Title of Invention

ROTATIONAL ANGLE DETECTING APPARATUS OF AN INTERNAL COMBUSION ENGINE

Abstract

A rotational angle detecting apparatus (52) for an internal combustion engine (2), comprises : a rotational motion transmitting member (14) wrapped with an endless rotational motion transmitting member (44) and attached to one end side, in an axial line direction, of a rotating shaft (12) axially supported by an engine constituent member (10) of the engine, a cover member (50) covering the endless rotational motion transmitting member (44) and the rotational motion transmitting member (14) and attached to the engine constituent member (46), an identifier member (54) for identifying a rotational angle integral with an attaching portion (32) of the rotational motion transmitting member (14), identifier portions (58), in correspondence with the rotational angle of the rotating shaft, provided on a side of the identifier member opposed to the cover member, detecting means (60) for detecting the rotational angle of the rotating shaft by identifying the identifier portions, the detecting means being attached to the engine constituent member (10) to be opposed to the identifier portions by being inserted into a through hole (62) of the cover member (50) opposed to the identifier member.

Full Text

BACKGROUND OF THE INVENTION 1. Field of the Invention : The present invention relates to a rotational angle detecting apparatus for an internal combustion engine, particularly to a rotational angle detecting apparatus for an internal combustion engine in which large size formation of a rotational motion transmitting member installed with an identifier member for detecting a rotational angle can be avoided, restriction of layout of detecting means can be reduced, vibration of a cover member can be reduced, positioning accuracy of the identifier member in respect of a rotating shaft can be promoted, a number of steps of integration can be reduced, the weight can be reduced, a reduction in the cost can be achieved, erroneous detection of the rotational angle can be prevented, reliability of control by the rotational angle can be promoted and which can be implemented also to an existing rotational angle detecting apparatus. 2. Description of the Related Art There is an internal combustion engine mounted on a vehicle, which is installed with a rotational angle detecting apparatus for detecting a rotational angle of a 1A rotating shaft for determining cylinders and identifying a rotational number of the engine. As such a rotational angle detecting apparatus, there is one shown by Fig. 23 through Fig. 25. In Fig. 23, numeral 102 designates an internal combustion engine, numeral 104 designates a crank shaft which is a rotating shaft, numeral 106 designates a crank timing pulley which is a rotational motion transmitting member and numeral 108 designates a rotational angle detecting apparatus. The internal combustion engine 102 is installed to attach a timing belt pulley 106 wrapped with a timing belt (not illustrated) which is an endless rotational motion transmitting member on one end side in the axial direction of the crank shaft 104 axially supported by a cylinder block 110 which is an engine constituting member. The rotational angle detecting apparatus 108 is installed with a sensing rotor 112 which is an identifier member for identifying a rotational angle to project from a side face of the timing belt pulley 106 attached to the crank shaft 104. As shown by Fig. 24 and Fig. 25, the sensing rotor 112 is installed with projected portions 116 constituting an identifier portion in correspondence with the rotational angle of the crank shaft 104 at a peripheral edge 114 to project to an outer side in a diameter direction. 2 The rotational angle detecting apparatus 108 is installed with a sensor 118 constituting detecting means for detecting the rotational angle of the crank shaft 104 by identifying the projected portions 116. The sensor 116 is installed to attach to the cylinder block 110 around the peripheral edge 114 of the sensing rotor 112 to direct to a center in the diameter direction and to dispose on the lower side of the crank shaft 104. The rotational angle detecting apparatus 108 detects the crank angle which is the rotational angle by identifying the projected portions 116 in correspondence with the rotational angle by the sensor 118. Further, as a rotational angle detecting apparatus, there is one shown by Fig. 26 and Fig. 27. The rotational angle detecting apparatus 208 shown by Fig. 26 and Fig. 27 is installed to attach a sensing rotor 212 at a shaft end of a cam shaft 204 which is a rotating shaft. The sensing . rotor 212 is installed with projected portions 216 in correspondence with the rotational angle of the cam shaft 204 to project from a peripheral edge 214. The rotational angle detecting apparatus 208 is installed to attach a sensor case 220 covering the sensing rotor 212 to a cylinder head (not illustrated) which is an engine constituting member. A sensor 218 for detecting the rotational angle of the cams shaft 204 by identifying the 3 projected portions 216, is attached to the sensor case 220 around the peripheral edge 214 of the sensing rotor 212 to direct to a center in a diameter direction and to dispose at a side of the cam shaft 204. The rotational angle detecting apparatus 208 detects a cam angle which is the rotational angle by identifying the projected portions 216 in correspondence with the rotational angle by the sensor 218. Further, as a rotational angle detecting apparatus, there is one shown by Fig. 28. A rotational angle detecting apparatus 308 shown by Fig. 28, is installed to attach a sensing rotor 312 at a side face of a timing belt pulley 306 which is a rotational motion transmitting member attached to a shaft end of a cam shaft 304 constituting a rotating shaft by attaching bolts 322 and to project projected portions 316 in correspondence with the rotational angle of the cam shaft 304 from a peripheral edge 314 of the sensing rotor 312 to outer sides in the diameter direction. The rotational angle detecting apparatus 308 is installed with a sensor 318 for detecting the rotational angle of the cam shaft 304 by identifying the projected portions 316. The sensor 318 is attached to a cylinder head, not illustrated, to direct to a center of the sensing rotor 312 in the diameter direction and to dispose 4 at a side of the cam shaft 304. The rotational angle detecting apparatus 308 detects a cam angle which is the rotational angle by identifying the projected portions 316 in correspondence with the rotational angle by the sensor 318. As such a rotational angle detecting apparatus of an internal combustion engine, there is one in which a sensing rotor constituting an identifier member for identifying a rotational angle and a sensor are integrally integrated to a case to thereby constitute an integral member and the integral member is integrated to an internal combustion engine as disclosed in JP-A-8-14814 and JP-A--8-144799. Further, as a rotational angle detecting apparatus of an internal combustion engine, there is one in which a sensor constituting detecting means is attached to a cylinder head or a head cover to direct to a center in a diameter direction of a sensing rotor constituting an identifier member for identifying the rotational angle as disclosed in JP-A-8-121206, JP-A-8-312512 and JP-A-9-280084. Further, as a rotational angle detecting apparatus of an internal combustion engine, there is one in which an identifier member in correspondence with a rotational angle is installed on an inner side face of a rim portion 5 of a cam pulley attached to a cam shaft and a sensor constituting detecting means is attached to a head cover to direct to the inner side face of the rim portion installed with the identifier portion as disclosed in JP-A-5-180613. Further, as a rotational angle detecting apparatus of an internal combustion engine, there is one in which a sensing rotor constituting an identifier portion for identifying a rotational angle is press-fitted and fixed to a timing belt pulley as disclosed in JP-A-8-135478 and there is one in which a sensor constituting detecting means is installed to attach to a cam cap of a cam shaft to direct to projected portions in correspondence with a rotational angle of a rear face of a cam pulley as disclosed in JP-A-9-88626. However, according to each of the conventional rotational angle detecting apparatus shown by Fig. 22 through Fig. 28, the identifier member for identifying the rotational angle is installed on the side face of the rotational motion transmitting member attached to the rotating shaft and the detecting means is arranged around the peripheral edge of the identifier member to direct to the center in the diameter direction. Therefore, there is a drawback in the rotational motion transmitting member installed with the identifier 6 member in which the rotational motion transmitting member is large-sized which gives rise to an increase in weight and gives rise to an increase in the length of the rotating shaft in the axial direction and layout of the detecting means is restricted. Further, when the rotational motion transmitting member installed to. the rotating shaft is a sprocket, the identifier portion in correspondence with the rotational angle needs to install to separate from a teeth portion of the sprocket such that the teeth portion installed at a peripheral edge of the sprocket is not erroneously identified as the identifier portion in correspondence with the rotational angle which is installed at the peripheral edge of the identifier member for identifying the rotational angle. Therefore, similar to the above-described, there is a drawback in which the rotational motion transmitting member installed with the identifier member gives rise to an increase in the length in the axial direction of the rotating shaft, becomes large-sized and gives rise to an increase in weight and layout of the detecting means is restricted. Further, when a separate identifier member for identifying the rotational angle is attached to a rotational motion transmitting member attached to a 7 rotating shaft, there poses a problem in which the positioning accuracy of the identifier member for identifying the rotational angle relative to the rotating shaft gets deteriorated owing to an error in the position of attachment of the rotational motion transmitting member relative to the rotating shaft as well as an error in the position of attachment of the identifier member relative to the rotational motion transmitting member. Accordingly, there is a drawback in the identifier portion in correspondence with the rotational angle installed to the identifier member in which a deviation is caused in a position of the rotational angle, erroneous detection of the rotational angle is caused in the detecting means and a reliability of control by the rotational angle is deteriorated. SUMMARY OF THE INVENTION Hence, in order to remove the above-mentioned drawback, the present invention provides a rotational angle detecting apparatus for an internal combustion engine, said apparatus comprising : a rotational motion transmitting member wrapped with an endless rotational motion transmitting member and attached to one end side, in an axial line direction, of a rotating shaft axially supported by an engine constituent member of the internal combustion engine ; a cover member covering said endless rotational motion transmitting member and said rotational motion transmitting member and attached to said engine 8 constituent member ; an identifier member for identifying a rotational angle, said identifier member being integral with an attaching portion of the rotational motion transmitting member for attaching it to the rotating shaft ; identifier portions, in correspondence with the rotational angle of the rotating shaft, provided on a side of the identifier member opposed to the cover member ; and detecting means for detecting the rotational angle of the rotating shaft by identifying the identifier portions, said detecting means being attached to the engine constituent member to be opposed to the identifier portions by being inserted into a through hole of the cover member opposed to the identifier member. In the rotational angle detecting apparatus, an identifying face may be provided on the side of the identifier member integral with the attaching portion of the rotational motion transmitting member to be opposed to the cover member and the identifier portions may be installed to be opposed to the detecting means in a peripheral direction of the identifying face. In a preferred embodiment, an identifying face on a side of the 9 identifier member installed integrally with the attaching portion of the rotational motion transmitting member to be opposed to the cover member and the identifier portions are installed to recess to be opposed to the detecting means in a peripheral direction of the identifying face, the rotational angle detecting apparatus is featured in that the rotational angle detecting apparatus is installed with an attaching hole at the attaching portion of the rotational motion transmitting member and the identifier member installed integrally with the attaching portion/ installed with the identifying face on the side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face, installed with a notch portion for positioning directed in the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner' side of the identifier portions in a diameter direction and installed with the notch portion to position on a diameter line the same as a diameter line of one of the identifier portions at the identifying face, and the rotational angle detecting apparatus is featured in that the rotational angle detecting apparatus is installed with an attaching hole at the attaching portion of the rotational motion 10 transmitting member and the identifier member installed integrally with the attaching portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner side of the identifier portions in a diameter direction and the notch portion is installed to position on a diameter line the same as a diameter line of one of the identifier portions at the identifying face and installed therewith such that a width of the notch portion becomes the same as a width of the identifier portions in respect of a peripheral direction of the identifying face. The rotational angle detecting apparatus is featured in that the rotational angle detecting apparatus is installed with an attaching hole at the attaching portion of the rotational motion transmitting member and the identifier member installed integrally with the attaching portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means along the attaching hole in 11 a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole and the notch portion is positioned to overlap one of the identifier portions at the identifying face, the rotational angle detecting apparatus is featured in that the rotational angle detecting apparatus is installed with an attaching hole at the attaching portion of the rotational motion transmitting member and the identifier member installed integrally with the attaching portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner side of the identifier portions in a diameter direction and installed with a stepped portion in a shape of a circular ring reaching an outermost end of the notch portion in a diameter direction from the attaching hole and recessed by a depth equal to or more than a depth of the identifier portions in the peripheral direction of the identifying face. 12 In a preferred embodiment of the rotational angle detecting apparatus, the identifying face is in a plane shape orthogonally intersecting with the axial line of the rotating shaft on a side of the identifier member installed integrally with the attaching portion of the rotational motion transmitting member opposed to the cover member and installed with, the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face in the plane shape. In another embodiment, the identifying face is in the shape of a conical face intersecting inclinedly with the axial line of the rotating shaft on a side of the identifier member installed integrally with the attaching portion of the rotational motion transmitting member opposed to the cover member and installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face in the shape of the conical face. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS In the accompanying drawings- Fig. 1 is a sectional view of an internal combustion engine installed with a rotational angle detecting apparatus showing a first embodiment of the invention; 13 Fig. 2 is an outline front view of the internal combustion engine; Fig. 3 is a front view of an intake sprocket; Fig. 4 is a sectional view of the intake sprocket; Fig. 5 is a sectional view enlarging essential portions of the intake sprocket; Fig. 6 is a perspective view of assembling the rotational angle detecting apparatus; Fig. 7 is an outline sectional view of the rotational angle detecting apparatus; Fig. 8 is a diagram showing a relationship among a position of a sensor relative to an identifier portion, generated voltage and an outputted rectangular wave; Fig. 9 is a sectional view of an internal combustion engine installed with a rotational angle detecting apparatus showing a second embodiment of the invention; Fig. 10 is an outline front view of the internal combustion engine; Fig. 11 is a front view of an intake sprocket; Fig. 12 is an outline sectional view of the rotational angle detecting apparatus; Fig. 13 is a sectional view enlarging essential portions of the intake sprocket; Fig. 14 is a diagram showing a rectangular wave outputted from a sensor; 14 Fig. 15 is a diagram showing a rectangular wave outputted by the sensor which detects an intake side notch portion for positioning as an identifier portion; Fig. 16 is a front view of an intake sprocket installed with a rotational angle detecting apparatus showing a third embodiment of the invention; Fig. 17 is a front view of an intake sprocket installed with a rotational angle detecting apparatus showing a fourth embodiment of the invention; Fig. 18 is a front view of an intake . sprocket installed with a rotational angle detecting apparatus showing a fifth embodiment of the invention; Fig. 19 is an outline sectional view of a rotational angle detecting apparatus showing a sixth embodiment of the invention; Fig. 20 is an outline sectional view of a rotational angle detecting apparatus showing a seventh embodiment of the invention; Fig. 21 is an outline sectional view of a rotational angle detecting apparatus showing an eighth embodiment of the invention; Fig. 22 is an outline sectional view of a rotational angle detecting apparatus showing a ninth embodiment of the invention; Fig. 23 is a sectional view of a crank shaft 15 installed with a rotational angle detecting apparatus showing a conventional example; Fig. 24 is a rear view of a crank sprocket; Fig. 25 is a sectional view of the crank sprocket; Fig. 26 is a perspective view of assembling a rotational angle detecting apparatus showing other conventional example; Fig. 27 is a sectional view showing a relationship between a sensing rotor and a sensor; and Fig. 28 is a perspective view of assembling a rotational angle detecting apparatus showing still other conventional example. DESCRIPTION OF THE PREFERRED EMBODIMENTS The rotational angle detecting apparatus of an internal combustion engine according to the invention, is installed with the identifier member for identifying the rotational angle at the attaching portion of the rotational motion transmitting member attached to the one end side in the axial line direction of the rotating shaft of the internal combustion engine and installed with identifier portions in correspondence with the rotational angle of the rotating shaft on the side of the identifier member opposed to the cover member by which large size formation of the rotational motion transmitting member and an increase in the length of the rotating shaft in the 16 axial line direction are not caused, the detecting means for detecting the rotational angle of the rotating shaft by identifying the identifier portions is attached to the engine constituent member such that the detecting means is inserted through the insertion hole of the cover member opposed to the identifier member to be opposed to the identifier portions and accordingly, vibration of the cover member can be restrained, layout of the detecting means is facilitated and the detecting means can be arranged proximate to the identifier member. The above-described identifier member is installed with the identifying face on the side of the identifier member installed integrally with the attaching portion of the rotational motion transmitting member opposed to the cover member and the identifier portions are installed to be opposed to the detecting means in the peripheral direction of the identifying face by which large si2e formation of the rotational motion transmitting member and the increase in the length of the rotating shaft in the axial line direction are not caused and the detecting means can be arranged proximate to the identifier member. Further, the rotational angle detecting apparatus is installed with the attaching hole at the attaching portion of the rotational motion transmitting member integrally installed therewith and the identifier member, installed 17 with the identifying face on the side of the identifier member opposed to the cover member and installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face and accordingly, when the rotational motion transmitting member is attached to the rotating shaft, an attaching jig does not interfere with the identifier portions and the rotational motion transmitting member can easily be attached thereto and the weight can be reduced. In this case, the rotational angle detecting apparatus is installed with the notch portion for positioning directed in the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole disposed on the inner side of the identifier portion in the diameter direction and installed with the notch portion to be disposed on a diameter direction line the same as that of one of the identifier portions at the identifying face by which a signal of erroneously identifying the notch as an identifier portion by the detecting means coincides with a regular identifying signal of the identifier portion and accordingly, the rotational angle is not erroneously detected. Further, the notch portion is installed to be disposed on the same diameter line of one of the 18 identifier portions at the identifying face and installed therewith such that a width of the notch portion is the same as that of the identifier portion in respect of the peripheral direction of the identifying face by which a width of the signal erroneously identifying the notch portion as the identifier portion by the detecting means can be made to coincide with a width of the regular identifying signal of the identifier portion and accordingly, erroneous detection of the rotational angle can be prevented with further certainty. Further, the rotational angle detecting apparatus is installed with the identifier portion to recess along the attaching hole in the peripheral direction of the identifying face and installed with the notch portion for positioning directed in the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole and the notch portion is installed to be disposed to overlap one of the identifier 'portions at the identifying face by which the notch portion can be utilized as one of the identifier portions, a number of machining can be reduced by reducing the identifier portion, recognition of the notch portion by detecting means can be made recognition of the regular identifier portion and the rotational angle is not erroneously detected. 19 Further, the rotational angle detecting apparatus is installed with the notch portion for positioning directed in the axial direction of the rotating shaft and reaching the identifying face in the attaching hole disposed on the inner side of the identifier portion in the diameter direction and installed with the stepped difference portion in the circular ring shape reaching the outermost end of the notch portion in the diameter direction from the attaching hole and recessed by the depth equal to or more than that of the identifier portion in the peripheral direction of the identifying face by which the portion installed with the identifier portion of the identifying face and the portion not installed therewith can be determined under the same condition and erroneous recognition can be dispensed with. Furthermore, the rotational angle detecting apparatus is installed with the identifying face in the plane shape orthogonally intersecting with the axial' line of the rotating shaft on the side of the identifier member opposed to the cover member and installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face , in the plane shape by which layout of the detecting means is facilitated, the detecting means can be arranged proximate to the identifier member, further, the 20 identifying face in the shape of the conical face intersecting inclinedly with the axial line of the rotating shaft is installed on the side of the identifier member opposed to the cover member and the identifier portions are installed to recess to be opposed to the detecting means in the peripheral direction of the identifying face in the shape of the conical face by which the length of the detecting means projecting from the cover member can be shortened and the rotational angle detecting apparatus can be arranged compactly. An explanation will be given of embodiments of the invention with reference to the accompanying drawings as follows. Fig. 1 through Fig. 8 show a first embodiment of the invention. In Fig. 1 and Fig. 2, numeral 2 designates an internal combustion engine having a plurality of cylinders. The internal combustion engine 2 is provided with a cylinder block 4, a cylinder head 6, a head cover 8 and a lower case 10. In the cylinder block 4 of the engine 2, a crank shaft 12, which is a rotating shaft, is axially supported by the lower case 10 and one end side of the crank shaft 12 in the axial direction is attached with a crank sprocket 14 which is a rotational motion transmitting member. Further, according to the internal combustion engine 21 2, in the cylinder head 6, an intake cam shaft 16 and an exhaust cam shaft 18 both constituting rotating shafts are axially supported respectively by an intake cam cap and an exhaust cam cap (not illustrated). The intake cam shaft 16 and the exhaust cam shaft 18 are installed with an intake side attaching boss portion 20 and an exhaust side attaching boss portion 22 on one end sides in the axial line directions and the intake side attaching boss portion 20 and the exhaust side attaching boss portion 22 are installed with an intake side through hole 24 and an exhaust side through hole 26 for positioning. The intake side attaching boss portion 20 and the exhaust side attaching boss portion 22 of the intake cam shaft 16 and the exhaust cam shaft 18 are respectively attached with an intake sprocket 28 and an exhaust sprocket 30 both constituting rotational motion transmitting members. The intake sprocket 2,8 and the exhaust sprocket 30 are respectively installed with an intake side attaching portion 32 and an exhaust side attaching portion 34 and installed with an intake side attaching hole 36 and an exhaust side attaching hole 38 fitted and press-fitted to the intake side attaching boss portion 20 and the exhaust side attaching boss portion 22. An intake side notch portion 40 and an exhaust side notch portion 42 for positioning in a groove shape which are 22 directed to the axial line directions of the intake cam shaft 16 and the exhaust cam shaft 18, are installed in the intake side attaching hole 36 and in the exhaust side attaching hole 38. The crank sprocket 14, the intake sprocket 28 and the exhaust sprocket 30 are wrapped with a timing chain 44 which is an endless rotational motion transmitting member. The timing chain 44 is held by being provided with a predetermined tension by a chain tensioner 46 and a chain holder 48, transmits rotational force of the crank shaft 12 to the intake cam shaft 16 and the exhaust cam shaft 18 and rotates the intake cam shaft 16 and the exhaust cam shaft 18 in synchronism with the crank shaft 12. As shown by Fig- 1, the crank sprocket 14, the intake sprocket 28 and the exhaust sprocket 30 and the timing chain 44 are covered by a chain cover 50 constituting a coyer member. The chain cover 50 is attached to the cylinder head 4 and the cylinder block 6 on one end side in the axial line direction of the crank shaft 12. The internal combustion engine 2 is installed with a rotational angle detecting apparatus 52 for detecting a rotational angle of the crank shaft 12, or the intake cam shaft 16 or the exhaust cam shaft 18 constituting a rotational shaft. The rotational angle detecting apparatus 52 according to the first embodiment detects a rotational 23 angle of the intake cam shaft 18. As shown by Fig. 3 through Fig. 5, the rotational angle detecting apparatus 52 is integrally installed with a sensing rotor 54 constituting an identifier member for identifying the rotational angle at the intake side attaching portion 32 of the intake sprocket 28 attached to the intake cam shaft 14. The sensing rotor 54 integrally installed to the intake side attaching portion 32 is installed with the intake side attaching hole 36, mentioned above. As shown by Fig. 4, the sensing rotor 54 is installed to a side opposed to the chain cover 50. An identifying face 56 is installed on the side of the sensing rotor 54 opposed to the chain cover 50. The identifying face 56 is installed in a plane shape orthogonally intersecting with the axial line of the intake cam shaft 16. The identifying face 56 in the plane shape is installed with identifier portions 58 in correspondence with the rotational angle of the intake cam shaft 14 in the peripheral direction on the outer side in the diameter direction to be opposed to the chain cover 50. The intake side notch portion 40 for positioning, mentioned above, directed in the axial line direction of the intake cam Shaft 16 and reaching the identifying face 58, is inst ailed in the intake side attaching hole 3 6 disposed on the identifying face 56 on the inner side of 24 the identifier portion 58 in the diameter direction. The identifier portions 58 according to the embodiment, are installed in the peripheral direction of the identifying face 56 to be recessed in a groove shape to be opposed to a sensor 60 constituting detecting means. The identifier portions 58 are identified by the sensor 60 by which the rotational angle of the intake cam shaft 16 is detected. As shown in Fig. 6 and Fig. 7, the sensor 60 is installed on the side of the chain cover 50 opposed to the sensing rotor 54. The chain cover 50 opposed to the sensing rotor 54 is provided with an insertion hole 62 for inserting the sensor 60. As shown in Fig. 2, the sensor 60 is inserted into the insertion hole 62, a flange 64 is brought into contact with the chain cover 50 and the sensor 60 is attached to the cylinder head 6 to be opposed to the identifier portions 58 by an attaching bolt 66. As shown in Fig. 1 and Fig. 2, in driving operation, the internal combustion engine 2 rotates the intake cam shaft 16 and the exhaust cam shaft 18 in synchronism with rotation of the crank shaft 12 by the timing chain 44 and drives to open and close an intake vale and an exhaust valve, not illustrated. 25 As shown in Fig. 6 and Fig. 7, the rotational angle detecting apparatus 52 is installed with the identifier portions 58 in correspondence with the rotational angle of the intake cam shaft 16 to be opposed to the chain cover 50, at the identifying face 56 of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake cam shaft 16 and the rotational angle is detected by identifying the identifier portions 58 by the sensor 60 installed on the side of the chain cover 50. As shown in Fig. 8, the sensor 60 generates a voltage which differs in accordance with a distance a1 to the identifying face 56 and a distance a2 to a bottom face 68 of the identifier portion 58 in the groove shape and forms the generated voltage in a rectangular wave in accordance with a threshold level by a built-in sensor circuit (not illustrated). The rectangular wave outputted from the sensor 60 is inputted to control means, (not illustrated) and is utilized in determining cylinders, in determining a crank angle or the like. The rotational angle detecting apparatus 52 according to the first embodiment is installed with the sensing rotor 54 for identifying the rotational angle at the intake side attaching portion 32 of the intake sprocket 28 26 attached to the intake cam shaft 16 of the internal combustion engine 2 and installed with the identifying porions 58 in the groove shape in correspondence with the rotational angle of the intake cam shaft 16 on the side of the sensing rotor 54 opposed to the chain cover 50 and accordingly, large size formation of the intake sprocket 28 and an increase in the length of the intake cam shaft 16 in the axial direction are not caused. Further, the rotational angle detecting apparatus 52 according to the first embodiment is installed to attach the sensor 60 for detecting the rotational angle of the intake cam shaft 16 by identifying the identifier portions 58 to the cylinder head 6 to be opposed to the identifier portions 58 by being inserted into the through hole 62 of the chain cover 50 opposed to the sensing rotor 54 and accordingly, vibration of the chain cover 50 can be restrained, layout of the sensor 60 is facilitated and the sensor 60 can be arranged proximate to 'the identifier portions 58. The sensing rotor 54 is installed integrally with the intake side attaching portion 32 of the intake sprocket 2$, installed with the identifying face 56 on the side opposed to the chain cover 50 and installed with the identifier portions 58 to be opposed to the sensor 60 in the peripheral direction of the identifying face 56 and 27 accordingly, the intake sprocket 28, the sensing rotor 54 and the identifier portions 58 can be machined simultaneously, a number of machining and a number of integration can be reduced, the positioning accuracy of the sensing rotor 54 in respect of the intake cam shaft 16 can be promoted, an error in integration can be eliminated, large size formation of the intake sprocket 28 and an increase in the length of the intake cam shaft 16 in the axial direction are not caused and the sensor 60 can be arranged proximate to the sensing rotor 54. That is, the rotational angle detecting apparatus 52 according to the first embodiment is installed with the identifier portions 58 by utilizing the identifying face 56 orthogonal to the axial line of the intake cam shaft 16 and accordingly, the detection is made possible by installing the identifier portions 58 having a small depth at the sensing rotor 54 installed integrally with the intake side attaching portion 32. When the detection is carried out by the sensor 118 installed around the peripheral edge 114 of the sensing rotor 112 to direct to the center in the diameter direction as in the conventional rotational angle detecting apparatus 108 shown by Fig. 23 through Fig. 25, there poses a problem in which in contrast to a very small change in the position of the sensor 118 relative to the crank shaft 104 which is 28 the rotating shaft, the distance between the peripheral edge 114 of the sensing rotor 112 and the projected portion US projected from the peripheral edge 114 needs to change significantly and accordingly, the height of the projected portion 116 must be large. By contrast, according to the rotational angle detecting apparatus 52 of the first embodiment, the detection is carried out by installing the identifier portions 58 at the identifying face 56 of the sensing rotor 54 orthogonal to the axial line of the intake cam shaft 16 mentioned above by which a change in the distance between the sensor 60 and the identifier portion 58 can be reduced in respect of a change in position in view of machining and a variation in driving the internal combustion engine 2, the detection can be carried out by machining the identifier portions 58 having a small depth at the sensing rotor 54 and large size formation of the intake side sprocket 28 installed with the sensing rotor 54 can be avoided. Further, as shown by Fig. 1 and Fig. 2, the rotational angle detecting apparatus 52 according to the first embodiment is installed with the identifying face 56 orthogonal to the axial line direction of the intake cam shaft 16 on the inner side in the diameter direction of teeth 68 of the intake sprocket 28 driven by the timing 29 chain 44 and installed with the identifier portions 58 at the identifying face 56 by which the sensor 60 can be arranged to be remote from the teeth 68 of the input sprocket 28 and erroneous detection caused by the teeth 68 of the intake sprocket 28 can be prevented. Further, the rotational angle detecting apparatus 52 according to the first embodiment is arranged with the sensor 60 on the side of the chain cover 50 to be attached to the cylinder head 6 by being inserted through the insertion hole 62 of the chain cover 50 and accordingly, vibration of the chain cover is restrained by the flange 64 of the sensor 60 and isolation of vibration can be achieved. Therefore, the rotational angle detecting apparatus 52 according to the first embodiment can avoid large size formation of the intake sprocket 58 installed with the sensing rotor 54 for detecting the rotational angle, can deduce restriction of layout of the sensor 60, can reduce vibration of the chain cover 50, can promote positioning accuracy of the sensing rotor 54 in respect of the intake cam shaft 16, can reduce a number of steps of integration, can reduce the weight, can achieve a reduction in the cost, can prevent erroneous detection of the rotational angle and can promote the reliability of control by the rotational angle. 30 Second Embodiment: Fig. 9 through Fig. 13 show a second embodiment of the invention- Further, an explanation will be given of the second embodiment by attaching the same notations to portions achieving functions the same as those in the first embodiment shown by Fig. 1 through Fig. 8, mentioned above. In Fig. 9 and Fig. 10, the internal combustion engine 2 is provided with the cylinder block 4, the cylinder head 6, the head cover 8 and the lower case 10 which are engine constituting members, in the cylinder block 4, the crank shaft 12 which is the rotational shaft is axially supported by the lower case 10 and the crank sprocket 14 which is the rotational motion transmitting member is attached to one end side in the axial direction of the crank shaft 12. The internal combustion engine 2 is installed with tlie intake side attaching boss portion 20 and the exhaust side attaching boss portion 22 on the one end sides in the axial line directions of the intake cam shaft 16 and the exhaust cam shaft 18 which are rotating shafts axially supported by the cylinder head 6 and the intake side attaching boss portion 20 and the exhaust side attaching boss portion 22 are installed with the intake side through hole 24 and the exhaust side through hole 26 for 31 positioning. The intake side attaching boss portion 20 and the exhaust side attaching boss portion 22 of the intake cam shaft 16 and the exhaust cam shaft 18 are respectively attached with the intake sprocket 28 and the exhaust sprocket 30 which are the rotational motion transmitting members. The intake sprocket 28 and the exhaust sprocket 30 are respectively installed with the intake side attaching portion 32 and the exhaust side attaching portion 34 and installed with the intake side attaching hole 36 and the exhaust side attaching holes '38 fitted and press-fitted to the intake side attaching boss portion 20 and the exhaust side attaching boss portion 22. The intake side notch portion 40 and the exhaust side notch portion 42 for positioning in a groove shape which are directed in the axial line directions of the intake cam shaft 16 and the exhaust cam shaft 18, are installed in the intake side attaching hole 36 and the exhaust side attaching hole 38. The crank sprocket 14, the intake sprocket 28 and the exhaust sprocket 30 are wrapped with the timing chain 44 which is the endless rotational motion transmitting member. The timing chain 44 is held by being provided with a predetermined tension by the chain tensioner 46 and the chain holder 48, transmits rotational force of the crank shaft 12 to the intake cam shaft 16 and the exhaust cam 32 shaft 18 and rotates the intake cam shaft 16 and the exhaust cam shaft 18 in synchronism with the crank shaft 12. The crank sprocket 14, the intake sprocket 28 and the exhaust sprocket 30 and the timing chain 44 are covered by the chain cover 50 constituting the cover member as shown by Fig. 9. The chain cover 50 is attached to the cylinder head 4 and the cylinder block 6 on the one end side of the crank shaft 12 in the axial direction. The internal combustion engine 2 is installed with the rotational angle detecting apparatus 52 for detecting the rotational angle of the crank shaft 12 or the intake cam shaft 16 or the exhaust cam shaft 18 which is the rotating shaft. The rotational angle detecting apparatus 52 according to the second embodiment detects the rotational angle of the intake cam shaft 18. As shown by Fig. 11 through Fig. 13, the rotational angle detecting apparatus 52 is integrally installed with the sensing rotor 54 which is the identifier member for identifying the rotational angle at the intake side attaching portion 32 of the intake sprocket 28 for attaching to the intake cam shaft 14. The sensing rotor 54 installed integrally with the intake side attaching portion 32 is installed with the intake side attaching hole 36, As shown by Fig. 9, the sensing rotor 54 is 33 installed on the side opposed to the chain cover 50. The identifying face 56 is installed on the side of the sensing rotor 54 opposed to the chain cover 50. The identifying face 56 is installed in the plane shape intersecting orthogonally with the axial line of the intake cam shaft 16. The identifying face 56 in the plane shape is installed with the identifier portions 58 in correspondence with the rotational angle of the intake cam shaft 14 in the peripheral direction on the outer side in the diameter direction to be opposed to the chain cover 50. The intake side notch portion 40 for positioning directed in the axial line direction of the intake cam shaft 16 and reaching the identifying face 58 is installed in the intake side attaching hole 36 disposed at the identifying face 56 on the inner side of the identifier portion 58 in the diameter direction. The identifier portions 58 are respectively installed to recess in the groove shape in the peripheral direction of the identifying face 56 to be opposed to the sensor 60 which is the detecting means. As shown by Fig. 11, the intake side notch portion 40 is installed to dispose on a diameter line L the same as that of the identifier portion 58 at the identifying face 56. The identifier portions 58 are identified by the sensor 60 by which the rotational angle of the intake cam 34 shaft 14 is detected. As shown by Fig. 12, the sensor 60 is installed on the side of the chain cover 50 to be opposed to the sensing rotor 54. The chain cover 50 opposed to the sensing rotor 54 is installed with the insertion hole 62 for inserting the sensor 60. As shown by Fig. 9, the sensor 60 is inserted into the insertion hole 62, the flange 64 is brought into contact with the chain cover 50 and is attached to the cylinder head 6 by the attaching bolt 66 to be opposed to the identifier portions 58. Next, an explanation will be given of the operation of the second embodiment. As shown by Fig. 9 and Fig. 10, in driving operation, the internal combustion engine 2 rotates the intake cam shaft 16 and the exhaust cam shaft 18 in synchronism with rotation of the crank shaft 12 by the timing chain 44 and drives to open and close an intake vale and an exhaust Vale, not illustrated- ' As shown by Fig. 11 through Fig. 13, the rotational angle detecting apparatus 52 is installed with the identifier portions 58 to recess in correspondence with the rotational angle of the intake cam shaft 14 to be opposed to the chain cover 50 at the identifying face 56 of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake cam shaft 35 16 and detects the rotational angle by identifying the identifier portions 58 by the sensor 60 installed on the side of the chain cover 50- As shown by Fig. 12, the sensor 60 generates a voltage which differs in accordance with the distance al to the identifying face 56 and the distance a2 to the bottom face 68 of the identifier portion 58 in the groove shape and forms the generated voltage in a rectangular wave in accordance with the threshold level by a built-in sensor circuit (not illustrated) as shown by Fig. 14. The rectangular wave outputted from the sensor 60 is inputted to control means, not illustrated, and is utilized in determining cylinders, in determining a crank angle or the like. The rotational angle detecting apparatus 52 according to the second embodiment is installed with the identifier portions 58 in correspondence with the rotational angle of the intake cam shaft 14 to be opposed to the chain cover 50 at the identifying face 56 of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake cam shaft 16 and installed with the sensor 60 for detecting the rotational angle by identifying the identifier portions 58 on the side of the chain cover 50. Accordingly, the rotational angle detecting apparatus 36 52 according to the second embodiment can achieve an effect similar to that of the first embodiment. The rotational angle detecting apparatus 52 according to the second embodiment is installed with the identifier portions 58 in correspondence with the rotational angle of the intake cam shaft 14 to be opposed to the chain cover 50 at the identifying face 56 of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 and accordingly, when the intake sprocket 28 is attached to the intake cam shaft 16, it can be attached easily without interfering with an attaching jig (not illustrated) and the weight can be reduced. That is, when the intake sprocket 28 and the exhaust sprocket 30 are attached to the intake cam shaft 16 and the exhaust cam shaft 18, firstly, the intake cam shaft 16 and the exhaust cam shaft 18 are fixed by positioning them to the cylinder head 6 by the intake side through hole 24 and the exhaust side through hole 26 for positioning, successively, the intake sprocket 28 and the exhaust sprocket 30 are positioned to the intake cam shaft 16 and the exhaust cam shaft 18 by the intake side notch portion 40 and the exhaust side notch portion 42 for positioning and press-fitted to the intake side attaching boss portion 20 and exhaust side attaching boss portion 22 by the 37 intake sidle attaching hole 3 6 and the exhaust side attaching hole 38. The press-fitting operation is carried out by an automatic machine and in that case, the machine searches the intake side through hole 24 and the exhaust side through hole 26 for positioning and the intake side notch portion 40 and the exhaust side notch portion 42 for positioning by rotating the intake sprocket 28 and the exhaust sprocket 30 and the intake cam shaft 16 and the exhaust cam shaft 18. At this occasion, when the identifier portions 58 are projected from the identifying face 56 of the sensing rotor 54, an attaching jig interferes with the identifier portions 58 and the respective sprockets 28 and 30 cannot be rotated. According to the rotational angle detecting apparatus 52 of the second embodiment, the identifier portions 58 are installed to recess from the identifying face 56 of the sensing rotor 54 and accordingly, when the intake sprocket 28 is attached to the intake cam shaft 16, the attaching jig does not interfere with the identifier portions 58, the intake sprocket 28 can easily be attached and the weight can be reduced, Further, the intake sprocket 28 installed with the sensing rotor 54 is installed with the intake side notch portion 40 for positioning reaching the identifying face 38 56 and is installed with the identifier portions 58 in correspondence with the rotational angle. Therefore, there is a case in which the sensor 60 erroneously recognizes the intake side notch portion 40 for positioning as the identifier portion 58 and detects it as a signal of the rotational angle as shown by Fig- 15. In this case, there is a drawback in which the reliability of control by rotational angle is deteriorated. As shown by Fig. 11, the rotational angle detecting apparatus 52 according to the second embodiment is installed with the identifier portions 58 in the peripheral direction on the outer side in the diameter direction of the identifying face 56 on the side opposed to the chain cover 50 of the sensing rotor 54 and installed with the intake side notch portion 40 installed in the intake side attaching hole 36 disposed at the identifying face 56 on the inner side of the identifier portion 58 in the diameter direction on trie diameter line L the same as that of one of the identifier portions 58 at the identifying face 56. Thereby, according to the rotational angle detecting apparatus 52 of the second embodiment, a signal which erroneously identifies the intake side notch portion 40 as the identifier portion 58 by the sensor 60, coincides with a regular identifying signal of the identifier portion 58 39 and accordingly, the rotational angle is not erroneously detected. Accordingly, the rotational angle detecting apparatus 52 according to the second embodiment can prevent erroneous detection of the rotational angle and can promote the reliability of control by the rotational angle. Third Embodiment: Fig. 16 shows a third embodiment of the invention. Further, an explanation will be given of the third embodiment by attaching the same notations to portions achieving functions the same as those of the first embodiment shown by Fig. 1 through Fig. 8, mentioned above. The rotational angle detecting apparatus 52 according to the third embodiment is installed with the intake side attaching hole 36 at the intake attaching portion 32 of the intake cam shaft 16 and the sensing rotor 54 installed integrally with the intake side attaching portion 32, installed with the identifying face 56 on 'the side of the sensing rotor 54 opposed to the chain cover 50, installed with the identifier portions 58 to recess in correspondence with the rotational angle in the peripheral direction on the outside of the identifying face 56 in the diameter direction to be opposed to the sensor 60, installed with the intake side notch portion 40 directed in the axial line direction of the intake cam shaft 16 and 40 reaching the identifying face 56 in the intake side attaching hole 36 disposed on the inner side of the identifier portion 58 in the diameter direction and installed with the intake side notch portion 40 to dispose on the diameter line L the same as that of one of the identifier portions 58 at the identifying face 56 and installed therewith such that the intake side notch portion 4 0 is provided with a width W the same as that of the identifier portion 58 in respect of the peripheral direction of the identifying face 56. The rotational angle detecting apparatus 52 according to the third embodiment is installed with the intake side notch portion 40 such that it is disposed on the diameter line L the same as that of one of the identifier portions 58 and its width is a width W the same as that of the identifier portion 58 and accordingly, a width of a signal for erroneously identifying the intake side notch portion 40 as the identifier portion 58 can be made to coincide with a width of a regular identifying signal of the identifier portion 58. Therefore, the rotational angle detecting apparatus 52 according to the third embodiment can achieve an effect similar to that ,of the first embodiment and can prevent erroneous detection of the rotational angle by the sensor 60 with further certainty. 41 Fourth Embodiment: Fig- 17 shows a fourth embodiment of the invention. Further, an explanation will be given of the fourth embodiment by attaching the same notations to portions achieving functions the same as those of the first embodiment shown by Fig. 1 through Fig. 8, mentioned above. The rotational angle detecting apparatus 52 according to the fourth embodiment is installed with the intake side attaching hole 36 at the intake side attaching portion 32 of the intake cam shaft 16 and the sensing rotor 54 installed integrally with the intake side attaching portion 32, installed with the identifying face 56 on the side of the sensing rotor 54 opposed to the chain cover 50, installed with the identifier portions 58 to recess in correspondence with the rotational angle in the peripheral direction on the inner side of the identifying face 56 in the diameter direction along the intake side attaching hole 36 to be opposed to the sensor 60, installed with the intake side notch portion 40 directed to the axial line direction of the intake cam shaft 16 and reaching the identifying face 56 in the intake side attaching hole 36 and installed with the intake side notch portion 40 of the intake cam shaft 16 to overlap one of the identifier portions 58 at the identifying face 56. In this way, the rotational angle detecting apparatus 42 52 according to the fourth embodiment is installed with the intake side notch portion 40 to coincide with one of the identifier portions 58 installed along the intake side attaching hole 36 and accordingly, the intake side notch portion 40 can be utilized as one of the identifier portions 58, a number of machining can be reduced by reducing a number of the identifier portions 58, recognition of the intake side notch portion 40 by the sensor 60 can be made recognition of a regular one of the identifier portions 58 and the rotational angle is not erroneously detected. Accordingly, the rotational angle detecting apparatus 52 according to the fourth embodiment can achieve an effect similar to that of the first embodiment, mentioned above, and erroneous detection of the rotational angle by the sensor 60 can be prevented with further certainty. Fifth Embodiment: Fig. 18 shows a fifth embodiment of the invention. Farther, an explanation will be given of the fifth embodiment by attaching the same notations to portions achieving functions the same as those of the first embodiment shown by Fig. 1 through Fig. 8, mentioned above. The rotational angle detecting apparatus 52 according to the fifth embodiment is installed with the intake side attaching hole 36 at the intake side attaching portion 32 43 of the intake cam shaft 16 and the sensing rotor 54 installed integrally with the intake side attaching portion 32, installed with the identifying face 56 on the side of the sensing rotor 54 opposed to the chain cover 50, installed with the identifier portions 58 to recess in correspondence with the rotational angle in the peripheral direction on the outer side of the identifying face 56 in the diameter direction to be opposed to the sensor 60, installed with the intake side notch portion 40 directed to the axial line direction of the intake cam shaft 16 and reaching the identifying face 56 in the intake side attaching hole 36 disposed on the inner side of the identifier portion 58 in the diameter direction and installed with a stepped portion 70 in a circular ring shape reaching an outermost end 40e of the intake side notch portion 40 in the diameter direction from the intake side attaching hole 36 and recessed by a depth equal to or more than that of the identifier portion 58 in the peripheral direction of the identifying face 56. In this way, the rotational angle detecting apparatus 52 according to the fifth embodiment is installed with the stepped portion 70 in the circular ring shape reaching the outermost end 40e of the intake side notch portion 40 in the diameter direction from the intake side attaching hole 36 and recessed by the depth equal to or more than that of 44 the identifier portion 58 in the peripheral direction of the identifying face 56 and accordingly, a portion of the identifying face 56 installed with the identifier portion 58 and a portion thereof not installed therewith can be determined under the same condition and erroneous recognition by the sensor 60 can be dispensed with. Accordingly, the rotational angle detecting apparatus 52 according to the fifth embodiment can achieve an effect similar to that of the first embodiment, mentioned above, and can prevent erroneous detection of the rotational angle by the sensor 60 with further certainty. Further,the rotational angle detecting apparatus 52 according to the fifth embodiment can prevent erroneous detection of the rotational angle by the sensor 60 with further certainty by implementing it in the identifying face 56 according to the first embodiment. Further, a depth h1 of the stepped portion 70 is set to be equal to a depth h2 of the identifier portion 58 (hl=h2) or larger than the depth h2 of the identifier portion 58 (hl>h2). Sixth Embodiment: Fig. 19 shows a sixth embodiment SG1 of the invention. Further, an explanation will be given of the sixth embodiment by attaching the same notations to portions achieving functions the same as those in the first embodiment shown by Fig. 1 through Fig. 8. mentioned above. 45 According to the respective embodiments, mentioned above, the identifying face 56 in the plane shape orthogonally intersecting with the axial line of the intake cam shaft 16 is installed on the side of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 opposed to the chain cover 50. According to the rotational angle detecting apparatus 52 of the sixth embodiment, the identifying face 56 in a shape of a conical face intersecting inclinedly with the axial line of the intake cam shaft 16 is installed on the side of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 opposed to the chain cover 50. The sensing rotors 54 is respectively installed with the identifier portions 58 to be opposed to the sensor 60 in the peripheral direction of the identifying face 56 in the conical face shape. In this way, according to the rotational angle detecting apparatus 52 of the sixth embodiment, the identifying face 56 in the conical face shape intersecting inclinedly with the axial line of the intake cam shaft -16 is installed on the side of the sensing rotor 54 opposed to the chain cover 50 and the identifier portions 58 are installed in the peripheral direction of the identifying face 56 by which the sensor 60 can be arranged proximate 46 to the sensing rotor 54 and can be arranged compactly. Accordingly, the rotational angle detecting apparatus 52 according to the sixth embodiment can achieve an effect similar to that of the first embodiment, mentioned above, and can contribute to small size formation of the internal combustion engine 2. Seventh Embodiment: Fig- 20 shows a seventh embodiment SG2 of the invention. The rotational angle detecting apparatus 52 according to the seventh embodiment is installed with the identifying face 56 in the plane shape orthogonally intersecting with the axial line of the intake cam shaft 16 on the side of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 to be opposed to the chain cover 50 and the identifying face 56 in the plane shape is installed with the identifier portions 58 having a section in a shape of a triangular embankment to' project in the peripheral direction on the outer side in the diameter direction. The identifier portion 58 is installed with a projected face 72 inclined to the identifying face 56 to direct in a skewed forward direction in the rotational direction of the sensing rotor 54 and the sensor 60 is installed to incline on the side of the chain cover 50 to 47 be opposed to the projected face 72 and to direct in a skewed rearward direction in the rotational direction of the sensing rotor 54. The rotational angle detecting apparatus 52 according to the seventh embodiment is installed with the inclined projected faces 72 at the identifier portions 58 projected from the identifying face 56 in the plane shape of the sensing rotor 54 and installed inclinedly with the sensor 60 to be opposed to the projected faces 72 by which the sensor 60 can be arranged proximate to the sensing rotor 54 and can be positioned on the inner side in the diameter direction of the sensing rotor 54 and can be arranged compactly and the internal combustion engine 2 can further be downsized. Further, according to the rotational angle detecting apparatus 52 of the seventh embodiment, the identifier portions 58 are moved to intersect with the sensor 60 by which the height of the projected face's 72 from the identifying face 56 is not constant as in the respective embodiments, mentioned above, but is varied to be higher or lower in accordance with the rotation of the sensing rotor 54 and accordingly, voltage outputted from the sensor 60 can be varied further significantly and the rotational angle can be detected further accurately. Eighth Embodiment: 48 Fig. 2:1 shows an eighth embodiment SG3 of the invention. The rotational angle detecting apparatus 52 according to the eighth embodiment is installed with the identifying face 56 in the plane shape orthogonally-intersecting with the axial line of the intake cam shaft 16 on the side of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 to be opposed to the chain cover 50 and the identifying face 56 in the plane shape is installed with the identifier portions 58 having a section in a shape of a triangular groove to recess in the peripheral direction on the outer side in the diameter direction. The identifier portions 58 are installed with recessed faces 74 inclined to the identifying face 56 to direct in a skewed forward direction in the rotational direction of the sensing rotor 54 and the sensor 60 is Installed to incline on the side of the chain cover 50 to be opposed to the recessed faces 74 and to direct in a skewed rearward direction in the rotational direction of the sensing rotor 54. The rotational angle detecting apparatus 52 according to the eighth embodiment is installed with the inclined projected faces 72 at the identifier portions 58 projected from the identifying face 56 in the plane shape of the 49 sensing rotor 54 and installed with the sensor 60 inclined to be opposed to the projected faces 72 and accordingly, the sensor 60 can be arranged further proximately to the sensing rotor 54 and can be positioned on the inner side of the sensing rotor 54 in the diameter direction and can be arranged compactly and the internal combustion engine 2 can further be downsized. Further, according to the rotational angle detecting apparatus 52 of the eighth embodiment, the identifier portions 58 are moved to intersect with the sensor 60 by which the height of the recessed faces 74 from the identifying face 56 is not constant as in the respective embodiments, mentioned above, but is varied to be higher or lower in accordance with the rotation of the sensing rotor 54 and accordingly, voltage outputted from the sensor 60 can be varied further significantly and the rotational angle can be detected further accurately. Ninth Embodiment: Fig. 22 shows a ninth embodiment SG4 of the invention. The rotational angle detecting apparatus 52 according to the ninth embodiment is installed with the identifying face 56 in the plane shape orthogonally intersecting with the axial line of the intake cam shaft 16 on the side of the sensing rotor 54 installed integrally with the intake side attaching portion 32 of the intake sprocket 28 to be 50 opposed to the chain cover 50 and installed with the identifier portions 58 to project in a shape of a triangular embankment in respect of the section and recessed in a shape of a triangular groove in respect of the section in the peripheral direction on the outer side of the identifying face 56 in the plane shape in the diameter direction. The identifier portion 58 is installed with a plane 76 to incline to intersect with the identifying face 56 to direct in a skewed forward direction in the rotational direction of the sensing rotor 54 and installed with the sensor 60 to incline on the side of the chain cover 50 to be opposed to the plane 76 and to direct in a skewed rearward direction in the rotational direction of the sensing rotor 54. The rotational angle detecting apparatus 52 according to the ninth embodiment is installed with the inclined planes 76 at the identifier portions 58' projected and recessed from the identifying face 56 in the plane shape of the sensing rotor 54 and installed with the sensor 60 inclined to be opposed to the planes 74 and accordingly, the sensor 60 can be arranged proximate to the sensing rotor 54, can be positioned on the inner side of the sensing rotor 54 and can be arranged compactly and the internal combustion engine 2 can be downsized. 51 Further, according to the rotational angle detecting apparatus 52 of the ninth embodiment, the identifier portions 58 are moved to intersect with the sensor 60 by which the height of the planes 76 from the identifying faces 56 is not constant as in the respective embodiments, mentioned above, and the area of the plane 76 is larger than those of the projected face 72 and the recessed face 74 according to the seventh and the eighth embodiments, mentioned above, by which the height of the planes 76 from the identifying face 56 are varied to be higher or lower further significantly in accordance with the rotation of the sensing rotor 54 and accordingly, the voltage outputted from the sensor 60 can be varied further significantly and the rotational angle can be detected further accurately. Further, although in the above-described respective embodiments, the sensing rotor 54 is installed integrally ¦with the intake sprocket 28, it is applicable also to the crank sprocket 14 or the exhaust sprocket 30 and is applicable to a timing pulley (not illustrated) other than the sprockets. Further, although the identifier portion-58 is installed to recess in the groove shape from the identifying face,. 56 of the sensing rotor 54, it can also be installed to project in a shape of an embankment. In this way, according to the rotational angle 52 detecting apparatus of an internal combustion engine of the invention, large size formation of a rotational motion transmitting member or an increase in a length of a rotating shaft in an axial line direction are not caused, layout of detecting means is facilitated, detecting means can be arranged to proximate to an identifier member, further, vibration of a cover member can be restrained, large size formation of the rotational motion transmitting member and an increase in the length of the rotating shaft in the axial line direction are not caused and the detecting means can be arranged proximate to the identifier member. Further, according to the rotational angle detecting apparatus of the invention, when a rotational motion transmitting member is attached to a rotating shaft, an attaching jig does not interfere with an identifier portion and it can easily be attached, the weight can be reduced, a timing erroneously identifying notched portions by detecting means coincides with a timing of regularly identifying the identifier portion and accordingly, the rotational angle is not erroneously detected. Further, according to the rotational angle detecting apparatus of the invention, a notch portion can be utilized as one of identifier portions, the weight can be reduced by reducing the identifier portions, recognition 53 of the notch portion by detecting means can be made identification of the regular identifier portion, the rotational angle is not erroneously detected, a portion installed with the identifier portion of an identifying face and a portion not installed therewith can be determined under the same condition and erroneous recognition can be dispensed with. Further, according to the rotational angle detecting apparatus of the invention, layout of detecting means is facilitated, the detecting means can be arranged proximate to an identifier member, a length of the detecting means projected from a cover member can be shortened and the rotational angle detecting apparatus can be arranged compactly. Therefore, according to the rotational angle detecting apparatus of the invention, large size formation of a rotational motion transmitting member installed with an identifier member for detecting the rotational angle can be avoided, restriction of layout of detecting means can be reduced, vibration of a cover member can be reduced, positioning accuracy of the identifier member in respect of a rotating shaft can be promoted, a number of steps of integration can be reduced, the weight can be reduced, a reduction in the cost can be achieved, erroneous detection of the rotational angle can be prevented, the reliability 54 of control by the rotational angle can be promoted and the rotational angle detecting apparatus can be implemented also to an existing rotational angle detecting apparatus. 55 WE CLAIM: 1. A rotational angle detecting apparatus (52) for an internal combustion engine (2), said apparatus comprising : a rotational motion transmitting member (14) wrapped with an endless rotational motion transmitting member (44) and attached to one end side, in an axial line direction, of a rotating shaft (12) axially supported by an engine constituent member (10) of the internal combustion engine ; a cover member (50) covering said endless rotational motion transmitting member (44) and. said rotational motion transmitting member (14) and attached to said engine constituent member ; an identifier member (54) for identifying a rotational angle, said identifier member being integral with an attaching portion (32) of the rotational motion transmitting member (14) for attaching it to the rotating shaft (16); identifier. portions (58), in correspondence with the rotational angle of the rotating shaft provided on a side of the identifier member opposed to the cover member (50) ; and detecting means (60) for detecting the rotational angle of the rotating shaft by identifying the identifier portions, said detecting means being attached to the engine constituent member (10) to be opposed to the identifier portions by being inserted into a through hole (62) of the cover member (50) opposed to the identifier member. 2. The apparatus as claimed in claim 1, wherein an identifying face (56) is provided on a side of the identifier member integral with the attaching portion (32) of- the rotational motion transmitting member to be opposed to the cover member and the identifier portions (58> are installed to be opposed to the detecting means in a peripheral direction of the identifying face. 56 3. The apparatus as claimed in claim 1, wherein an identifying face is provided on a side of the identifier member integral with the attaching portion of the rotational motion transmitting member to be opposed to the cover member and the identifier portions are installed in a recess (60) to be opposed to the detecting means in a peripheral direction of the identifying face. 4. The apparatus of as claimed in claim 3, comprising an attaching hole (62) provided at the attaching portion of the rotational motion transmitting member and the identifier member installed integral with the attaching portion, installed with the identifying face on the side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face, installed with a notch portion for positioning directed in the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner side of the identifier portions in a diameter direction and installed with the notch portion to position on a diameter line the same as a diameter line of one of the identifier portions at the identifying face. 5. The apparatus as claimed in claim 3, comprising an attaching hole provided at the attaching portion of the rotational motion transmitting member and the identifier member installed integral with the attaching 57 portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner side of the identifier portions in a diameter direction and the notch portion is installed to position on a diameter line the same as a diameter line of one of the identifier portions at the identifying face and installed therewith such that the width of the notch portion becomes the same as a width of the identifier portions in respect of a peripheral direction of the identifying face. 6. The apparatus as claimed in claim 3, comprising an attaching hole provided at the attaching portion of the rotational motion transmitting member and the identifier member installed integrally with the attaching portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means along the attaching hole in a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial line direction of the rotating shaft and reaching the identifying face in the attaching hole and the notch portion is positioned to overlap one of the identifier portions at the identifying face. 58 7. The apparatus as claimed in claim 3, comprising an attaching hole provided at the attaching portion of the rotational motion transmitting member and the identifier member installed integrally with the attaching portion, installed with the identifying face on a side of the identifier member opposed to the cover member, installed with the identifier portions to recess to be opposed to the detecting means in a peripheral direction of the identifying face, installed with a notch portion for positioning directed to the axial direction of the rotating shaft and reaching the identifying face in the attaching hole positioned on an inner side of the identifier portions in a diameter direction and installed with a stepped portion in a shape of a circular ring reaching an outermost end of the notch portion in a diameter direction from the attaching hole and recessed by a depth equal to or more than a depth of the identifier portions in the peripheral direction of the identifying face. 8. The apparatus as claimed in any one of claims 3 to 7, comprising the identifying face in a plane shape orthogonally intersecting with the axial line of the rotating shaft on a side of the identifier member installed integrally with the attaching portion of the rotational motion transmitting member opposed to the cover member and installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face in the plane shape. 59 9. The apparatus as claimed in any one of claims 3 to 7, comprising the identifying face in a shape of a conical face intersecting inclinedly with the axial line of the rotating shaft on a side of the identifier member installed integrally with the attaching portion of the rotational motion transmitting member opposed to the cover member and installed with the identifier portions to recess to be opposed to the detecting means in the peripheral direction of the identifying face in the shape of the conical face. 10. A rotational angle detecting apparatus for an internal combustion engine, substantially as herein described, particularly with reference to and as illustrated in the accompanying drawings. 11. An internal combustion engine incorporating a rotational angle detecting apparatus as claimed in any of claims 1 to 9. Dated this 19th day of May, 1999. -60- A rotational angle detecting apparatus (52) for an internal combustion engine (2), comprises : a rotational motion transmitting member (14) wrapped with an endless rotational motion transmitting member (44) and attached to one end side, in an axial line direction, of a rotating shaft (12) axially supported by an engine constituent member (10) of the engine, a cover member (50) covering the endless rotational motion transmitting member (44) and the rotational motion transmitting member (14) and attached to the engine constituent member (46), an identifier member (54) for identifying a rotational angle integral with an attaching portion (32) of the rotational motion transmitting member (14), identifier portions (58), in correspondence with the rotational angle of the rotating shaft, provided on a side of the identifier member opposed to the cover member, detecting means (60) for detecting the rotational angle of the rotating shaft by identifying the identifier portions, the detecting means being attached to the engine constituent member (10) to be opposed to the identifier portions by being inserted into a through hole (62) of the cover member (50) opposed to the identifier member.

Documents:

00471-cal-1999 abstract.pdf

00471-cal-1999 claims.pdf

00471-cal-1999 correspondence.pdf

00471-cal-1999 description (complete).pdf

00471-cal-1999 drawings.pdf

00471-cal-1999 form-1.pdf

00471-cal-1999 form-18.pdf

00471-cal-1999 form-2.pdf

00471-cal-1999 form-3.pdf

00471-cal-1999 form-5.pdf

00471-cal-1999 gpa.pdf

00471-cal-1999 priority document other.pdf

00471-cal-1999 priority document.pdf

471-cal-1999-granted-abstract.pdf

471-cal-1999-granted-claims.pdf

471-cal-1999-granted-correspondence.pdf

471-cal-1999-granted-description (complete).pdf

471-cal-1999-granted-drawings.pdf

471-cal-1999-granted-form 1.pdf

471-cal-1999-granted-form 18.pdf

471-cal-1999-granted-form 2.pdf

471-cal-1999-granted-form 3.pdf

471-cal-1999-granted-form 5.pdf

471-cal-1999-granted-gpa.pdf

471-cal-1999-granted-letter patent.pdf

471-cal-1999-granted-priority document.pdf

471-cal-1999-granted-reply to examination report.pdf

471-cal-1999-granted-specification.pdf

471-cal-1999-granted-translated copy of priority document.pdf