Title of Invention	COVER STRUCTURE FOR ENGINE
Abstract	To increase rigidity so that a sprocket cover can be fastened at two points, upper and lower. [Constitution] A clamp 31 is integrally protruded rearward from a back wall 30 of an ACG cover 6 provided on a left case cover 5 to thereby support a sensor harness 15. The sprocket cover 7 covers the sensor harness 15 from above to cover an output sprocket 11, and is fastened to a crankcase 1 at two points, upper and lower, with bolts 13 and 14. At this time, the end of the clamp 31 abuts on and supports an inner surface of a front edge 7b, thereby increasing rigidity of the front edge 7b to allow fastening with only two portions, upper and lower.

Title of Invention

COVER STRUCTURE FOR ENGINE

Abstract

To increase rigidity so that a sprocket cover can be fastened at two points, upper and lower. [Constitution] A clamp 31 is integrally protruded rearward from a back wall 30 of an ACG cover 6 provided on a left case cover 5 to thereby support a sensor harness 15. The sprocket cover 7 covers the sensor harness 15 from above to cover an output sprocket 11, and is fastened to a crankcase 1 at two points, upper and lower, with bolts 13 and 14. At this time, the end of the clamp 31 abuts on and supports an inner surface of a front edge 7b, thereby increasing rigidity of the front edge 7b to allow fastening with only two portions, upper and lower.

Full Text	[Document Name] Specification [Title of the Invention] COVER STRUCTURE FOR ENGINE [Technical Field] [0001] The present invention relates to a cover structure for an engine, and more particularly, to a cover structure for an engine allowing a protective cover for externally covering an output sproclcet to be mounted at fewer mounting points, with high support rigidity. [Background Art] [0002] There has been known a structure in which an output shaft for outputting power of an engine is provided to extend on the side of an engine case mounted on a saddle-ride type vehicle, and an output sprocket is provided on the output shaft extension portion, and in which a sprocket cover for covering the output sprocket is fastened to the engine case with bolts. [Citation List] [Patent Literature] [0003] [Patent Literature 1] JP-A No. 2007-290640 [Summary of Invention] [Technical Problem] [0004] When fastening the above-described sprocket cover, however, an unfixed edge, for example, a front edge, becomes unstable at the time of external bolting, and therefore, there has been a need to perform fastening in such unstable state. Also, for improvement in workability/ fastening points are preferably minimized, for example, two points. However, since the sprocket cover is disposed at the outermost portion of the engine case and below the engine, high rigidity is required. Therefore, when the fastening points are reduced to, for example, two, it has been difficult to increase rigidity of the sprocket cover. Accordingly, an object of the present invention is to provide a cover structure for an engine allowing a protective cover, such as a sprocket cover, to be mounted at fewer points, with high rigidity. [Solution to Problem] [0005] In order to address the above-described problem, a cover structure for an engine according to the present invention includes: an engine case; an output shaft supported by the engine case; an output sprocket co-rotatably attached to an extension portion of the output shaft protruding from the engine case; a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and a detector supported by the engine case for detecting a state of the engine and including a harness extending outwardly from the engine, in which the engine case is externally covered with a case cover including an expanding portion expanding outwardly, wherein a cover-side rib is provided for guiding the harness between the cover-side rib and the expanding portion while protruding outwardly, leaving a predetermined space from the expanding portion of the case cover, the cover-side rib abutting on and supporting an inner surf ace of the protective cover, and wherein the protective cover includes an end placed between a protective cover abutting portion of the cover-side rib and'the expanding portion. [0006] Furthermore, in a cover structure for an engine including the premise parts common with above, a case cover extension portion is provided, the case cover extension portion extending in an axial direction of the output shaft from the case cover. Also, the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case. Further, the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Additionally, the protective cover includes an end placed between the cover rib and the expanding portion. [Advantageous Effects of Invention] [0007] When the protective cover is mounted on an outer surface of the engine case, the protective cover is allowed to abut on the cover-side rib provided on the case cover. Thus, a depth of the protective cover is regulated and positioning at the time of assembly is performed, thereby improving assembly performance. Also, even when the fastening points are reduced in number, the inner side of the protective cover is supported by the cover-side rib to thereby increase strength of inward stress from outside. In addition, by externally covering the harness with the' protective cover while guiding the harness with the engine case, it is possible to protect the harness with simple structure. [0008] Also, instead of the cover-side rib, there is provided a case cover extension portion extending in an axial direction of the output shaft from the case cover. Also, the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case. Further, the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Additionally, the protective cover includes an end placed between the cover rib and the expanding portion. The inwardly protruding cover rib provided on the protective cover abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Even with this structure, the same advantages as the above can be achieved. [Brief Description of Drawings] [0009] [Fig. 1] Fig. 1 is a left side view of an air-cooled engine for a motorcycle. [Fig. 2] Fig. 2 is a partially sectional view of the engine taken along the line 2-2 of Fig. 1. [Fig. 3] Fig. 3 is an enlarged sectional view of a back wall . and a clamp. [Fig. 4] Fig. 4 is a sectional view taken along the line 4-4 of Fig. 1. [Fig. 5] Fig. 5 is a left side view of a left case cover and a sprocket cover. [Fig. 6] Fig. 6 is a left side view of an air-cooled engine for a motorcycle according to a second embodiment. [Fig. 7] Fig. 7 is a left side view of a left crankcase. [Fig. 8] Fig. 8 is a left side view of a left case cover. [Fig. 9] Fig. 9 is a rear view of the left crankcase. [Fig. 10] Fig. 10 is a side view of a sprocket cover. [Fig. 11] Fig. 11 is a sectional view taken along the line 11-11 of Fig. 6. [Fig. 12] Fig. 12 is a sectional view taken along the line 12-12 of Fig. 6. [Fig. 13] Fig. 13 is an enlarged sectional view of the same portion as Fig. 3, according to a third embodiment. [Fig. 14] Fig. 14 is an enlarged view of the essential parts of a fourth embodiment with a further modification made to the third embodiment. [Description of Embodiments] [0010] An embodiment will hereinafter be described with reference to the accompanying drawings. Figs. 1 to 5 correspond to a first embodiment, and Fig. 1 is a left side view of an air-cooled engine for a motorcycle. The engine includes a crankcase 1, a cylinder block 2 provided above the front of the crankcase 1 and tilted slightly forward in a vertical direction, a cylinder head 3 superposed on the cylinder block 2, and a cylinder head cover 4 for covering the cylinder head 3. [0011] On'a side surface of the crankcase 1, a left case cover 5 for covering a left side surface thereof is mounted, and a part of the left case cover 5 forms an ACG cover 6 expanding outward in an approximately bowl shape. A sprocket cover 7 formed separately from the left case cover 5 is attached to the rear of the left case cover 5, and a front edge 7b of a front portion 7a of the sprocket cover 7 is disposed along a rear edge of the left case cover 5. The left case cover 5 is made of metal with high rigidity, and formed by light alloy casting or the like. The sprocket cover 7 is formed of appropriate material, and, in this embodiment, made of resin. [0012] On a rear edge 7f of the sprocket cover 7, there is provided a recess 7g recessed forward,at a vertically intermediate portion thereof and formed in an approximately semicircular shape, and a pivot 8 for swingably supporting a front end of a rear fork (not shown) faces the recess 7g. The pivot shaft of the pivot 8 is supported by a pivot frame 9 vertically disposed in the rear of the engine. [0013] The sprocket cover 7 externally covers an output sprocket 11 provided on an output shaft 10 of the engine at a center thereof, and a part of a chain 12 wound around the output sprocket 11. Also, an upper portion 7d and a lower portion 7e are fastened to the crankcase 1 at two points, upper and lower, with bolts 13 and 14, respectively. [0014] The front portion 7a of the sprocket cover 7 covers a part of a sensor harness 15 vertically wired between the ACG cover 6 and the output sprocket 11, and a position sensor 16 connected to a lower end of the sensor harness 15. The sensor harness 15 extends outwardly and upwardly from an upper edge of the sprocket cover 7 to be connected to an ECU (not shown) disposed above the crankcase 1. [0015] The position sensor 16 is a sensor for detecting a shift position by detecting rotation of a shift drum to be described later. Also, the position sensor 16 is disposed below the rear of the ACG cover 6, and covered with a projection 7c formed to protrude downwardly at a lower portion of the front portion 7a of the sprocket cover 7. Reference numeral 17 denotes a spindle shaft for rotating the shift drum. The spindle shaft 17 is provided below the output sprocket 11 and at a bottom of the crankcase 1, and is rotated by operation of a shift pedal not shown. [0016] Here, the left case cover 5 is an example corresponding to a case cover of the present invention; the ACG cover 6, expanding portion; the sprocket cover 7, a protective cover; the sensor harness 15, a harness; the position sensor 16, a detector, [0017] Fig. 2 is a partially sectional view of the engine taken along the line 2-2 of Fig. 1. The crankcase 1 is separated into left and right in a vehicle width direction, and composed of left and right crankcases 20 and 21. The exterior of the left crankca^e 20- is laterally covered with the left case cover 5 and the sprocket cover 7, and the exterior of the right crankcase 21 is covered with a right case cover 22. The engine case is composed of the left crankcase 20, the right crankcase 21, the left case cover 5 and the right case cover 22. In the crankcase 1, a crankshaft 23, a main shaft 24, and a countershaft 25 are rotatable with their respective axes parallel. The countershaft 25 and the output shaft 10 are coaxial, and the output shaft 10 is formed integrally with an axial end of the countershaft 25. [0018] The crankshaft 23 is rotationally driven by a connecting rod 27 integral with a piston 26 sliding in a cylinder 2a of the cylinder block 2. ; One end (the left end in this embodiment) of the crankshaft 23 protrudes outwardly from the left crankcase 20, and an ACG 28 is supported thereon. The ACG 28 is a known generator, and is expanded outwardly from the left crankcase 20. Also, the ACG cover 6 for covering the ACG 28 is outwardly expanded. [0019] The main shaft 24 and the countershaft 25 constitute a transmission, and a gear train (not shown) is provided on the main shaft 24 and the output shaft 10. Driving force transmitted from the crankshaft 23 to the main shaft 24 is changed by the gear train, and gear change output is transmitted from the countershaft 25 to the output shaft 10. One end of the output shaft 10 protrudes outwardly from the left crankcase 20 to co-rotatably support the output sprocket 11. [0020]' Fig. 3 is an enlarged view of the periphery of the output sprocket 11. A clamp 31 is integrally provided on a back wall 30, that is, a portion of the ACG cover 6 facing the front edge 7b of the sprocket cover 7. The clamp 31 has an approximately L-shaped section composed of a base portion 32 bent at an approximately right angle rearward from the back wall 30, and a support protrusion 33 bent at an approximately right angle further outward from a rear end thereof and formed in a vertical wall shape to protrude rearward from the back wall 30. Also, when the left case cover 5 is formed by casting or the like, the clamp 31 is formed integrally therewith, however, may be formed as a separate body from the left case cover 5, and then integrated therewith by welding or the like. [0021] The support protrusion 33 protrudes outwardly approximately parallel to the back wall 30 so as to form a predetermined clearance corresponding to a protruding length of the base portion 32 between the back wall 30 and the support protrusion 33. A clamp groove 34 having an approximately U-shaped section is formed of the back wall 30, the base portion 32, and the support protrusion 33, and an open portion of the clamp' groove 34 faces outward. The support protrusion 33 of the clamp 31 is an example corresponding to a cover-side rib of the present invention. [0022] The sensor harness 15 is stored within the clamp groove 34, and an overlap portion 41 is formed at the front edge 7b of the ' sprocket cover 7. A support rib 40 integrally formed to protrude from the overlap portion 41 toward the base portion 32 of the clamp 31 is inserted into the clamp groove 34, and located on the outer upper side of the sensor harness 15 to prevent the sensor harness 15 from falling out of the clamp groove 34. [0023] The base portion 32 of the clamp 31 is provided at a position approximately half the height (the length expanding outwardly from the outer surface of the left crankcase 20) of the back wall 30, and at a position outwardly distant from the outer surface of the left crankcase 20. Also, corners of the clamp 31 are generally rounded at the time of molding to remove sharp edges. Thus, the base portion 32 regulates a position of the innermost portion of the sensor harness 15. Also, even when the base portion 32 supports the sensor harness 15 in contact therewith, the base portion 32 having no sharp edges causes no damage to the sensor harness 15. In addition, the sensor harness 15 is placed away from the outer surface of the left crankcase 20 to thereby prevent the sensor harness 15 from being brought into contact with the outer surface of the left crankcase 20, so that any damage caused by the contact with the outer surface of the left crankcase 20 is prevented. [0024] The end of the support protrusion 33 abuts, at a position just behind the support rib 40, on an inner surface of the front edge of the sprocket cover 7. Therefore, the front edge 7b of the sprocket cover 7 is supported from inside by the clamp 31. 10 This allows'an increase in rigidity when the sprocket cover 7 is mounted. Also, even by fastening at only two points, upper and lower, sufficient rigidity of the front edge 7b when mounted is maintained. In particular, even when the sprocket cover 7 is made of resin as described in this embodiment, the front portion 7a including the front edge 7b can have a thin wall thickness of about 2.5 mm. [0025] 5 The support rib 40 may be widely continuously formed along the front edge 7b or alternatively, may be partially formed corresponding to the clamp 31. When the support rib 40 is partially provided in this manner, falling-out prevention using the overlap portion 41 becomes particularly effective. [0026] On the sprocket cover 7, a partition wall 42 protrudes integrally, inward from an inner surface of the front portion 7a, behind of the clamp 31. The partition wall 42 extends inward longer than the clamp 31 to reach an outer surface of the left crankcase 20 at its end. The partition wall 42 is a vertical rib for covering to surround a front half side in a radial direction of the output sprocket 11. Reference numeral 43 denotes a cylindrical portion protruding integrally from an inner surface of an intermediate portion of the sprocket cover 7 to the vicinity of an outer surface of the output sprocket 11. [0027] On an outer surface of the left crankcase 20, in the vicinity of a bearing portion 50 for supporting an axial end 11 of the main'Shaft 24, ribs 51 and 52 are formed in front and in the rear, respectively, to protrude outward. An inner end of the back wall 30 of the ACG cover 6 abuts on the end of the front rib 51. A chain guide 53 is supported on the end of the rear rib 52, and the end of the partition wall 42 abuts on an outer surface of the chain guide 53. [0028] , The chain guide 53 is located in front of and above the center in the width direction of the chain 12, and is a member for guiding smooth rotation of the chain 12. Also, on the front half side in a radial direction of the output sprocket 11, the chain guide 53 is formed in an approximately half-circular arc shape to surround the chain 12. The front of the output sprocket 11 and the chain 12 is separated from the ACG cover 6 side by the rib 52, the chain guide 53, and the partition wall 42. The output sprocket 11 is disposed in the separate space, and is co-rotatably attached to an end of the output shaft 10 protruding from an outer surface of the left crankcase 20. The output shaft 10 is supported by a bearing 54 provided on the left crankcase 20. [0029] Fig. 4 is a sectional view taken along the line 4-4 of Fig. 1. The respective ends of the support protrusions 33 of the clamps 31 abut on inner surfaces of the front edge 7b of the sprocket cover 7. Among those abutting portions, on the upper and lower abutting portions, flat seat portions 44 are formed. The seat portions 44 abut on the support protrusions 33. On the abutting portion of the intermediate support 12 protrusion 33, no special seat portion is formed since the inner surface of the front edge 7b is originally substantially flat. In this manner, the abutting portions are formed of flat surfaces, thereby further ensuring support of the front edge 7b with the support protrusions 33. [0030] The sprocket cover 7 is fixed by the bolt 13 with a boss 45 provided on the upper portion 7d superposed on a corresponding boss 55 provided on an outer surface of the left crankcase 20. At this time, the chain guide 53 is also sandwiched between the bosses 45 and 55 to be fastened together. Also, the lower portion 7e is fixed by the bolt 14 with a boss 46 previously provided thereon superposed on a corresponding boss 56 of the left crankcase 20. At this time, a lower portion of the partition wall 42 is situated below the output sprocket 11 to abut on a side surface of the chain guide 53 also situated below the output sprocket 11, thereby separating the position sensor 16 located below the partition wall 42, and the output sprocket 11 from each other, so that adhesion to the position sensor 16 of mud, or the like, splashed from the side of the output sprocket 11 and the chain 12, is effectively prevented. [0031] A sensor mounting hole 57 is provided in a lower portion of the side surface of the left crankcase 20, below the output sprocket 11 and the partition plate 42, and the position sensor 16 is fitted therein to be fixed by a bolt 58. An axial end portion of a shift drum 29 is fitted in the sensor mounting hole 57. The position sensor 16 is connected to a protrusion 29a 13 provide'd at'an axial end of the shift drum 29, so that rotation of the shift drum 29 can be detected by the position sensor 16. [0032] Fig. 5 is an enlarged left side view of the left case cover 5 and the sprocket cover 7. The front edge 7b of the sprocket cover 7 includes an approximately half-circular arc-shaped portion with an edge facing the ACG cover 6 curved around a rear portion of the ACG cover 6, and is superposed on a rear edge of the left case cover 5. The clamps 31 overlap with the inside of an upper portion, an intermediate portion, and a lower portion of the front edge 7b. [0033] On the rear edge of the left case cover 5, a total of the three clamps 31 are provided leaving a predetermined space therebetween in a vertical direction. The sensor harness 15 is guided by those clamps 31 to be vertically wired substantially along the rear surface of the back wall 30. Reference numerals 35 denote bosses provided on rear edges of the left case cover for fastening the left case cover 5 to the left crankcase 20, and overlapping with the undersurface of the sprocket cover 7. Reference numeral 36 denotes another mounting boss provided on the periphery of the left case cover 5. [0034] The expanding portion of the ACG cover 6, the clamps 31, the bosses 35, and the like, are dislocated from center line L between the upper and lower bolts 13 and 14. Also, the upper and lower bolts 13 and 14 are positioned point-symmetrically with respect to center 0 of the output sprocket 11. With such 14 structure, even when the number of fastening portions is reduced, it is possible to easily and readily mount the sprocket cover 7. [0035] Further, when the sprocket cover 7 is laterally mounted on the left crankcase 20, the respective ends of the support protrusions 33 of the clamps 31 abut on inner surfaces of the front portion 7a of the sprocket cover 7. Thus, a depth of the front edge 7b of the sprocket cover 7 is regulated and positioned, and therefore assembly performance is improved. This allows improvement in workability of the assembly. [003 6] Also, even when the fastening points are reduced to two, by supporting the inner side of the sprocket cover 7 using the support protrusions 33 of the clamps 31 to increase strength of inward stress from outside, it is possible to sufficiently enhance support rigidity. In addition, by externally covering the sensor harness 15 with the sprocket cover 7 while guiding the sensor harness 15 with the left case cover 5, it is possible to protect the sensor harness 15 with simple structure. [0037] Next, a second embodiment will be described. Figs. 6 to 12 correspond to the second embodiment. Fig. 6 is a left side view of an engine; Fig. 7 is a left side view of a left crankcase; Fig. 8 is a left side view of a left case cover; Fig. 9 is a rear view of the left crankcase; Fig. 10 is a side view of a sprocket cover; Fig. 11 is a sectional view taken along the line 11-11 of Fig. 6; and Fig. 12 is a sectional view taken along , 15 the line 1-2-12 of Fig. 6. Here, the second embodiment also relates to wiring of a sensor harness with the left case cover and the sprocket cover of the air-cooled engine, the same as the foregoing embodiment. In the second embodiment, therefore, the component parts common with the foregoing embodiment are designated by common reference numerals, and their description is omitted except in case of necessity. [0038] In Fig. 6, the left case cover 5 integrally includes the ACG cover 6 formed to be expanded, and is laterally fastened to the left crankcase 20 with the bosses 35 and 36. In the rear of the left case cover 5, the sprocket cover 7 is attached to the left crankcase 20 at two portions, upper and lower, with the bolts 13 and 14 to laterally cover the output sprocket 11. The front edge of the sprocket cover 7 overlaps with the rear edge of the left case cover 5, and the sensor harness 15 is vertically wired in the overlapping portion. This structure is the same as the foregoing embodiment. [0039] As shown in Fig. 7, the left crankcase 20 includes an ACG container 60 in front, and an output sprocket container 61 in the rear. Between the ACG container 60 and the output sprocket container 61, the chain guide 53 formed in an approximately half-circular arc shape is opened rearward, and mounted to cover a front portion of the output sprocket container 61. The sensor mounting hole 57 is provided below the left crankcase 20 and between the ACG container 60 and the chain guide 16 53. A dpindle hole 62 through which the spindle shaft passes is provided in the rear of and adjacent to the sensor mounting hold 57. [0040] Reference numeral 63 denotes a mounting portion for the chain guide 53, and the mounting portions 63 are provided at two points, upper and lower. The upper mounting portion 63, and the boss 45 provided on the sprocket cover 7 are fastened together with the bolt 13. Reference numeral 64 denotes a boss, provided on the left crankcase 20, to which the boss 46 of the sprocket cover 7 is fastened with the bolt 14. Reference numerals 65 denote bosses, overlapping with the sprocket cover 7, of mounting bosses for the left case cover 5. Reference, numerals 66 denote other mounting bosses. [0041] As shown in Figs. 8 and 9, the clamp 31 is integrally provided on the back wall 30 of the left case cover 5. The clamp 31 is composed of a flange 70 connecting the upper and lower bosses 35 to extend from the back wall 30 toward the output shaft 10 provided in the rear, and clamp ribs 72 and 73 provided at upper and lower portions thereof. The rear edge of the flange 70 has an approximately circular arc-shaped portion 71 curved around the chain guide 53. The clamp ribs 72 and 73 protrude integrally upward from upper and lower portions of the flange 70, respectively. The upper edge of the clamp rib 72 as shown in Fig. 8 is placed substantially perpendicular in the vertical direction. The-upper edge of the clamp rib 73 is tilted forward so that an upper 17 portio'n of the upper edge is positionedx forward. [0042] The clamp ribs 72 and 73 are adjacent to the upper and lower bosses 35, respectively. The upper and lower bosses 35 are fixed in a superposed manner on the upper and lower bosses 65 (Fig. 7) formed on the left crankcase 20. The bosses 36 to be fixed in a superposed manner on the other plural bosses 66 provided on the left crankcase 20, are provided on the periphery of the left case cover 5. [0043] As shown in Fig. 9, the clamp ribs 72 and 73 are provided at a higher position (outer side) than the bosses 35 to guide the sensor harness 15 between the back wall 30 and the clamp ribs, so that the sensor harness 15 is prevented from approaching the bosses 35. Also, the flange 70 vertically elongated is provided as the equivalent of the base portion 32 according to the foregoing embodiment. This allows the flange 70 to support the sensor harness 15 on the left crankcase 20 over a long distance, so that the sensor harness 15 can be less likely to be brought into contact with the left crankcase 20. [0044] As shown in Fig. 10, in the center of the sprocket cover 7, the cylindrical portion 43 extending to the outer surface of the output sprocket 11 is integrally provided. Also, the partition wall 42 is integrally provided so as to surround the front of the cylindrical portion 43 in an approximately half-circular arc shape. The partition wall 42 is superposed on the chain guide 53 to form a wall for covering the front of 18 the output'Sprocket 11. [0045] A front portion 42a of the partition wall 42 continues, with a stepped portion 42b, to a rear portion on the bosses 35, and a rear portion thereof is drawn further rearward than a virtual position extended forward, so that a certain clearance is provided between the front portion 42a and the flange 70 (Fig. 8) disposed in front of the front portion 42a. Either end of the partition wall 42 continues to the upper and lower bosses 45 and 46. With this structure, even when the partition wall 42 is elongated along the circumferential direction of the output sprocket 11, either end of the partition wall 42 is integrated with the bosses 45 and 46 having high rigidity, thereby obtaining sufficient rigidity. [0046] On an inner surface of the front edge 7b located in front of the partition wall 42, support ribs 40a and 40b are integrally formed at upper and lower portions thereof to protrude inward. The support ribs 40a and 40b correspond to the clamp ribs 72 and 73 of the left case cover 5, respectively. The upper support rib 40a is disposed forward of the clamp rib 72, leaving a predetermined space therebetween, with approximately the same size as the clamp rib 72, and approximately parallel thereto. Also, the lower support rib 40b is disposed forward of the clamp rib 73, leaving a predetermined space therebetween, with approximately the same size as the clamp rib 72, and approximately parallel thereto. ■ [0047] 19 pis shdwn in Fig. 11, when the sprocket cover 7 is mounted, the overlap portion 41 of the front edge 7b is superposed on the flange 70, and edges of the clamp ribs 72 and 73 abut on inner surfaces of the front edge located in the rear of the support ribs 40a and 40b to thereby support the sprocket cover 7. The support ribs 40a and 40b are inserted into the clamp groove 34 formed between the clamp ribs 72 and 73, and the back wall 30 to hold the upper side of the sensor harness 15 previously stored within the clamp groove 34. ■[0048] Further, the front edge 7b is formed with the front thereof upwardly tilted. However, since the support ribs 40a and 40b are provided in front, and the partition wall 42 is provided in the rear to support the clamp ribs 72 and 73 therebetween, rigidity of the front edge 7b is increased. Also, even in the case where the front edge 7b is formed in such a manner, deformation, such as enlargement of the opening, is avoided, and the front edge 7b is kept steady. [0049] As shown in Fig. 12, the portion provided without the support ribs 4 0a and 4 0b of the front edge 7b covers the upper side of the flange 70 with the formation of the overlap portion 41. Since the sensor harness 15 is guided above the flange 70, the upper side of the sensor harness 15 is held by the overlap portion 41, thereby allowing falling-out prevention. In ^ addition, although no clamp rib 72 (73) is provided in the rear of the flange 70, the partition wall 42 instead of the clamp rib 72 (73) is disposed slightly rearward away from the rear 20 edge of the'flange 70, thereby allowing the sensor harness 15 to be guided from the rear of the vehicle by utilizing the partition wall 42. ■ [0050] As described above, according to this embodiment, it is possible to reduce the number of the support ribs 40a and 40b or the clamp ribs 72 and 73, and simplify clamp structure. Further, the sensor harness 15 can be guided over a long distance by the flange 70. Therefore, guiding is facilitated, and damage to the sensor harness 15 by the left crankcase 20 becomes less likely to be caused. In addition to this, this embodiment can achieve the same advantages as the foregoing embodiment. Also, placement of the chain guide 53 as shown in Fig. 7, the structure of the rear surface of the ACG cover 6 on the left case cover 5 as shown in Fig. 8, and the structure of the partition portion 42 as shown in Fig. 10 can be employed in the foregoing first embodiment. [0051] Next, a third embodiment will be described with reference to Fig. 13. Fig. 13 is an enlarged sectional view of the same portion as Fig. 3. In the third embodiment, a rear extension portion 90 is formed to protrude from the back wall 30, in a direction perpendicular to the axis of the output shaft 10 provided in the rear, in an approximately tongue shape, and a flat surface thereof faces outward. The end of the rear extension portion 90 extends to about the vicinity of a peripheral position of the output sprocket 11, and the end of an integral strut rib 47 extending, at a substantially right 21 angle,'inwardly from an inner surface of the front portion 7a, abuts on the end of the rear extension portion 90 . In this manner, the end of the strut rib 47 abuts on the rear extension portion 90 to be supported, so that the inner surface of the front portion 7a is supported by the back wall 30. Therefore, support rigidity of the front portion 7a including the front edge 7b can be still increased. [0052] The rear extension portion 90 corresponds to the base portion 32 and the flange 70 according to the foregoing respective embodiments. However, the rear extension portion 90 differs from those in that the rear extension portion 90 is integrally provided to protrude in an elongated manner, and in that the rear extension portion 90 is provided without the support protrusions 33, or the clamp ribs 72 and 73 with the respective ends thereof abutting directly on the inner surface of the front portion 7a. However, a protrusion formed in a short rib sjiape, or the like, may be provided to protrude from the rear extension portion 90 for allowing the respective ends of the protrusion and the strut rib 47 to abut on each other. Here, the rear extension portion 90 is an example corresponding to a case cover extension portion of the present invention, and the strut rib 47 is an example corresponding to a cover rib of the present invention. [0053] With this structure, a storing space 91 for the sensor harness 15 is formed of the back wall 30, the rear extension portion 90, and the strut rib 47, and is covered with the overlap 22 portion 41 extending forward over the strut rib 47 of the front portion 7a to overlap with an upper portion of the rear extension portion 90. Therefore, abutting of the strut rib 47 and the rear extension portion 90 allows the front portion 7a to be supported by the left case cover 5, and allows an increase in rigidity. Also, the rear extension portion 90 can be relatively downsized with a simple shape. Therefore, when the rear extension portion 90 is molded integrally with the left case cover 5, the left case cover 5 can be easily molded. [0054] Fig. 14 illustrates a fourth embodiment with a further modification made to Fig. 13. A small rib 92 protrudes from the rear extension portion 90 toward the overlap portion 41, and a small rib 48 also protrudes from the overlap portion 41 towards the rear extension portion 90. The respective ribs 92 and 48 are displaced from each other in a front-rear direction, leaving a space therebetween so as to prevent the ribs 92 and 48 from reaching the respective counter sides thereof and so as to prevent the ribs 92 and 48 from vertically abutting on each other, to hold the sensor harness 15 with their respective ends. With this structure, the expanded space of the storing space 91 can be freely adjusted by changing the size or position of the two ribs 92 and 48. Even when the sensor harness 15 becomes thick or flat, therefore, the sensor harness 15 can be reliably held. '[0055] 23 'It should be understood that the present invention is not limited to the above-described embodiments. Various modifications and applications may be made within the principle of the invention. For example, any detector for detecting a state of an engine can be used instead of the position sensor 16. The harness is not only the sensor harness for the position sensor 16, but also can be variously changed according to a detector. Further, the expanding portion of the engine case is not only the ACG cover, but also any expanding portion capable of guiding the harness can be employed. Also, the protective cover is not necessarily limited to the sprocket cover 7. Alternatively, any cover for laterally covering the output sprocket 11 can be used. For example, a member referred to as a left rear cover, or the like, may be used. [Reference Signs List] [0056] 1. . .Crankcase 5...Left case cover 6...ACG cover 7...Sprocket cover 10...Output shaft 11...Output sprocket 15...Sensor harness 16... Position sensor 20...Left crankcase 30...Back wall 24 31...Clamp 35...Boss 36...Boss 37...Vertical wall 38...Clamp groove 40...Rib 47...Strut rib 72, 73...Clamp rib 90...Rear expansion portion [Document Name] Claims [Claim 1] A cover structure for an engine, comprising: an engine case; an output shaft supported by the engine case; an output sprocket co-rotatably attached to an extension portion of the output shaft protruding from the engine ca?e; a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and a detector supported by the engine case for detecting a state of the engine and including a harness extending outwardly from the engine, in which the engine case is externally covered with a case cover including an expanding portio'n expanding outwardly, wherein a cover-side rib is provided for guiding the harness between the cover-side rib and the expanding portion while protruding outwardly, leaving a predetermined space from the expanding portion of the case cover, the cover-side rib abutting on and supporting an inner surface of the protective cover, and wherein the protective cover includes an end placed between a protective cover abutting portion of the cover-side rib and the expanding portion. [Claim 2] A cover structure for an engine, comprising: an engine case; an output shaft supported by the engine case; an output sprocket co-rotatably attached to an extension porti6n of' the output shaft protruding from the engine case;' a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and a detector supported by the engine case for detecting a state of the engine and including a harness extending outwardly from the engine, in which the engine case is externally covered with a case cover including an expanding portion expanding outwardly, , wherein a case cover extension portion is provided, the case cover extension portion extending from the case cover • toward the output shaft, wherein the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case, wherein the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib, and wherein the protective cover includes an end placed between the cover rib and the expanding portion. [Claim 3] The cover structure for the engine according to Claim 1 or 2, wherein the protective cover is fastened to the engine case at a plurality of fastening portions, the fastening portions being disposed approximately point-symmetrically with respect to a center of the output shaft, and wherein the rib provided on the case cover or on the protective cover, and the expanding portion are dislocated from a line' between the approximately point-symmetrically disposed fastening portions. [Claim 4] •• The cover structure for the engine according to any one of Claims 1 to 3, wherein an ACQ supported on a crankshaft is provided outwardly of the engine case, and the expanding portion of the case cover is an ACG cover for covering the ACG. [Claim 5] The cover structure for the engine according to any one of Claims 1 to 4, wherein the detector is disposed below the output shaft, and is a position detecting sensor for detecting a rotational position of a shift drum, the position detecting sensor being externally covered with the protective cover.

Full Text

[Document Name] Specification
[Title of the Invention] COVER STRUCTURE FOR ENGINE
[Technical Field]
[0001]
The present invention relates to a cover structure for an engine, and more particularly, to a cover structure for an engine allowing a protective cover for externally covering an output sproclcet to be mounted at fewer mounting points, with high support rigidity. [Background Art]
[0002]
There has been known a structure in which an output shaft for outputting power of an engine is provided to extend on the side of an engine case mounted on a saddle-ride type vehicle, and an output sprocket is provided on the output shaft extension portion, and in which a sprocket cover for covering the output sprocket is fastened to the engine case with bolts. [Citation List] [Patent Literature]
[0003]
[Patent Literature 1] JP-A No. 2007-290640 [Summary of Invention] [Technical Problem]
[0004]
When fastening the above-described sprocket cover, however, an unfixed edge, for example, a front edge, becomes unstable at the time of external bolting, and therefore, there has been a need to perform fastening in such unstable state.

Also, for improvement in workability/ fastening points are preferably minimized, for example, two points. However, since the sprocket cover is disposed at the outermost portion of the engine case and below the engine, high rigidity is required. Therefore, when the fastening points are reduced to, for example, two, it has been difficult to increase rigidity of the sprocket cover.
Accordingly, an object of the present invention is to provide a cover structure for an engine allowing a protective cover, such as a sprocket cover, to be mounted at fewer points, with high rigidity. [Solution to Problem] [0005]
In order to address the above-described problem, a cover structure for an engine according to the present invention includes: an engine case; an output shaft supported by the engine case; an output sprocket co-rotatably attached to an extension portion of the output shaft protruding from the engine case; a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and a detector supported by the engine case for detecting a state of the engine and including a harness extending outwardly from the engine, in which the engine case is externally covered with a case cover including an expanding portion expanding outwardly, wherein a cover-side rib is provided for guiding the harness between the cover-side rib and the expanding portion while protruding outwardly, leaving a predetermined space from the expanding portion of the case cover, the cover-side rib abutting on and

supporting an inner surf ace of the protective cover, and wherein the protective cover includes an end placed between a protective cover abutting portion of the cover-side rib and'the expanding portion. [0006]
Furthermore, in a cover structure for an engine including the premise parts common with above, a case cover extension portion is provided, the case cover extension portion extending in an axial direction of the output shaft from the case cover. Also, the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case. Further, the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Additionally, the protective cover includes an end placed between the cover rib and the expanding portion. [Advantageous Effects of Invention] [0007]
When the protective cover is mounted on an outer surface of the engine case, the protective cover is allowed to abut on the cover-side rib provided on the case cover. Thus, a depth of the protective cover is regulated and positioning at the time of assembly is performed, thereby improving assembly performance.
Also, even when the fastening points are reduced in number, the inner side of the protective cover is supported by the cover-side rib to thereby increase strength of inward stress from outside. In addition, by externally covering the harness

with the' protective cover while guiding the harness with the engine case, it is possible to protect the harness with simple structure.
[0008]
Also, instead of the cover-side rib, there is provided a case cover extension portion extending in an axial direction of the output shaft from the case cover. Also, the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case. Further, the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Additionally, the protective cover includes an end placed between the cover rib and the expanding portion. The inwardly protruding cover rib provided on the protective cover abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib. Even with this structure, the same advantages as the above can be achieved. [Brief Description of Drawings]
[0009] [Fig. 1] Fig. 1 is a left side view of an air-cooled engine for a motorcycle.
[Fig. 2] Fig. 2 is a partially sectional view of the engine taken along the line 2-2 of Fig. 1.
[Fig. 3] Fig. 3 is an enlarged sectional view of a back wall . and a clamp.
[Fig. 4] Fig. 4 is a sectional view taken along the line 4-4 of Fig. 1.

[Fig. 5] Fig. 5 is a left side view of a left case cover and
a sprocket cover.
[Fig. 6] Fig. 6 is a left side view of an air-cooled engine for a motorcycle according to a second embodiment.
[Fig. 7] Fig. 7 is a left side view of a left crankcase.
[Fig. 8] Fig. 8 is a left side view of a left case cover.
[Fig. 9] Fig. 9 is a rear view of the left crankcase.
[Fig. 10] Fig. 10 is a side view of a sprocket cover.
[Fig. 11] Fig. 11 is a sectional view taken along the line
11-11 of Fig. 6.
[Fig. 12] Fig. 12 is a sectional view taken along the line
12-12 of Fig. 6.
[Fig. 13] Fig. 13 is an enlarged sectional view of the same portion as Fig. 3, according to a third embodiment.
[Fig. 14] Fig. 14 is an enlarged view of the essential parts of a fourth embodiment with a further modification made to the third embodiment. [Description of Embodiments] [0010]
An embodiment will hereinafter be described with reference to the accompanying drawings. Figs. 1 to 5 correspond to a first embodiment, and Fig. 1 is a left side view of an air-cooled engine for a motorcycle. The engine includes a crankcase 1, a cylinder block 2 provided above the front of the crankcase 1 and tilted slightly forward in a vertical direction, a cylinder head 3 superposed on the cylinder block 2, and a cylinder head cover 4 for covering the cylinder head 3. [0011]

On'a side surface of the crankcase 1, a left case cover 5 for covering a left side surface thereof is mounted, and a part of the left case cover 5 forms an ACG cover 6 expanding outward in an approximately bowl shape. A sprocket cover 7 formed separately from the left case cover 5 is attached to the rear of the left case cover 5, and a front edge 7b of a front portion 7a of the sprocket cover 7 is disposed along a rear edge of the left case cover 5. The left case cover 5 is made of metal with high rigidity, and formed by light alloy casting or the like. The sprocket cover 7 is formed of appropriate material, and, in this embodiment, made of resin.
[0012]
On a rear edge 7f of the sprocket cover 7, there is provided a recess 7g recessed forward,at a vertically intermediate portion thereof and formed in an approximately semicircular shape, and a pivot 8 for swingably supporting a front end of a rear fork (not shown) faces the recess 7g. The pivot shaft of the pivot 8 is supported by a pivot frame 9 vertically disposed in the rear of the engine.
[0013]
The sprocket cover 7 externally covers an output sprocket 11 provided on an output shaft 10 of the engine at a center thereof, and a part of a chain 12 wound around the output sprocket 11. Also, an upper portion 7d and a lower portion 7e are fastened to the crankcase 1 at two points, upper and lower, with bolts 13 and 14, respectively.
[0014]
The front portion 7a of the sprocket cover 7 covers a part

of a sensor harness 15 vertically wired between the ACG cover 6 and the output sprocket 11, and a position sensor 16 connected to a lower end of the sensor harness 15. The sensor harness 15 extends outwardly and upwardly from an upper edge of the sprocket cover 7 to be connected to an ECU (not shown) disposed above the crankcase 1.
[0015]
The position sensor 16 is a sensor for detecting a shift position by detecting rotation of a shift drum to be described later. Also, the position sensor 16 is disposed below the rear of the ACG cover 6, and covered with a projection 7c formed to protrude downwardly at a lower portion of the front portion 7a of the sprocket cover 7. Reference numeral 17 denotes a spindle shaft for rotating the shift drum. The spindle shaft 17 is provided below the output sprocket 11 and at a bottom of the crankcase 1, and is rotated by operation of a shift pedal not shown.
[0016]
Here, the left case cover 5 is an example corresponding to a case cover of the present invention; the ACG cover 6, expanding portion; the sprocket cover 7, a protective cover; the sensor harness 15, a harness; the position sensor 16, a detector,
[0017]
Fig. 2 is a partially sectional view of the engine taken along the line 2-2 of Fig. 1. The crankcase 1 is separated into left and right in a vehicle width direction, and composed of left and right crankcases 20 and 21. The exterior of the left

crankca^e 20- is laterally covered with the left case cover 5 and the sprocket cover 7, and the exterior of the right crankcase 21 is covered with a right case cover 22. The engine case is composed of the left crankcase 20, the right crankcase 21, the left case cover 5 and the right case cover 22. In the crankcase 1, a crankshaft 23, a main shaft 24, and a countershaft 25 are rotatable with their respective axes parallel. The countershaft 25 and the output shaft 10 are coaxial, and the output shaft 10 is formed integrally with an axial end of the countershaft 25.
[0018]
The crankshaft 23 is rotationally driven by a connecting rod 27 integral with a piston 26 sliding in a cylinder 2a of the cylinder block 2.
; One end (the left end in this embodiment) of the crankshaft 23 protrudes outwardly from the left crankcase 20, and an ACG 28 is supported thereon. The ACG 28 is a known generator, and is expanded outwardly from the left crankcase 20. Also, the ACG cover 6 for covering the ACG 28 is outwardly expanded.
[0019]
The main shaft 24 and the countershaft 25 constitute a transmission, and a gear train (not shown) is provided on the main shaft 24 and the output shaft 10. Driving force transmitted from the crankshaft 23 to the main shaft 24 is changed by the gear train, and gear change output is transmitted from the countershaft 25 to the output shaft 10. One end of the output shaft 10 protrudes outwardly from the left crankcase 20 to co-rotatably support the output sprocket 11.

[0020]'
Fig. 3 is an enlarged view of the periphery of the output sprocket 11. A clamp 31 is integrally provided on a back wall 30, that is, a portion of the ACG cover 6 facing the front edge 7b of the sprocket cover 7. The clamp 31 has an approximately L-shaped section composed of a base portion 32 bent at an approximately right angle rearward from the back wall 30, and a support protrusion 33 bent at an approximately right angle further outward from a rear end thereof and formed in a vertical wall shape to protrude rearward from the back wall 30. Also, when the left case cover 5 is formed by casting or the like, the clamp 31 is formed integrally therewith, however, may be formed as a separate body from the left case cover 5, and then integrated therewith by welding or the like. [0021]
The support protrusion 33 protrudes outwardly approximately parallel to the back wall 30 so as to form a predetermined clearance corresponding to a protruding length of the base portion 32 between the back wall 30 and the support protrusion 33. A clamp groove 34 having an approximately U-shaped section is formed of the back wall 30, the base portion 32, and the support protrusion 33, and an open portion of the clamp' groove 34 faces outward.
The support protrusion 33 of the clamp 31 is an example corresponding to a cover-side rib of the present invention. [0022]
The sensor harness 15 is stored within the clamp groove 34, and an overlap portion 41 is formed at the front edge 7b

of the ' sprocket cover 7. A support rib 40 integrally formed to protrude from the overlap portion 41 toward the base portion 32 of the clamp 31 is inserted into the clamp groove 34, and located on the outer upper side of the sensor harness 15 to prevent the sensor harness 15 from falling out of the clamp groove 34. [0023]
The base portion 32 of the clamp 31 is provided at a position approximately half the height (the length expanding outwardly from the outer surface of the left crankcase 20) of the back wall 30, and at a position outwardly distant from the outer surface of the left crankcase 20. Also, corners of the clamp 31 are generally rounded at the time of molding to remove sharp edges. Thus, the base portion 32 regulates a position of the innermost portion of the sensor harness 15. Also, even when the base portion 32 supports the sensor harness 15 in contact therewith, the base portion 32 having no sharp edges causes no damage to the sensor harness 15. In addition, the sensor harness 15 is placed away from the outer surface of the left crankcase 20 to thereby prevent the sensor harness 15 from being brought into contact with the outer surface of the left crankcase 20, so that any damage caused by the contact with the outer surface of the left crankcase 20 is prevented. [0024]
The end of the support protrusion 33 abuts, at a position just behind the support rib 40, on an inner surface of the front edge of the sprocket cover 7. Therefore, the front edge 7b of the sprocket cover 7 is supported from inside by the clamp 31.
10

This allows'an increase in rigidity when the sprocket cover 7 is mounted. Also, even by fastening at only two points, upper and lower, sufficient rigidity of the front edge 7b when mounted is maintained. In particular, even when the sprocket cover 7 is made of resin as described in this embodiment, the front portion 7a including the front edge 7b can have a thin wall thickness of about 2.5 mm.
[0025]
5 The support rib 40 may be widely continuously formed along the front edge 7b or alternatively, may be partially formed corresponding to the clamp 31. When the support rib 40 is partially provided in this manner, falling-out prevention using the overlap portion 41 becomes particularly effective.
[0026]
On the sprocket cover 7, a partition wall 42 protrudes integrally, inward from an inner surface of the front portion 7a, behind of the clamp 31. The partition wall 42 extends inward longer than the clamp 31 to reach an outer surface of the left crankcase 20 at its end. The partition wall 42 is a vertical rib for covering to surround a front half side in a radial direction of the output sprocket 11. Reference numeral 43 denotes a cylindrical portion protruding integrally from an inner surface of an intermediate portion of the sprocket cover 7 to the vicinity of an outer surface of the output sprocket 11.
[0027]
On an outer surface of the left crankcase 20, in the vicinity of a bearing portion 50 for supporting an axial end
11

of the main'Shaft 24, ribs 51 and 52 are formed in front and
in the rear, respectively, to protrude outward. An inner end
of the back wall 30 of the ACG cover 6 abuts on the end of the
front rib 51. A chain guide 53 is supported on the end of the
rear rib 52, and the end of the partition wall 42 abuts on an
outer surface of the chain guide 53.
[0028] ,
The chain guide 53 is located in front of and above the center in the width direction of the chain 12, and is a member for guiding smooth rotation of the chain 12. Also, on the front half side in a radial direction of the output sprocket 11, the chain guide 53 is formed in an approximately half-circular arc shape to surround the chain 12.
The front of the output sprocket 11 and the chain 12 is separated from the ACG cover 6 side by the rib 52, the chain guide 53, and the partition wall 42. The output sprocket 11 is disposed in the separate space, and is co-rotatably attached to an end of the output shaft 10 protruding from an outer surface of the left crankcase 20. The output shaft 10 is supported by a bearing 54 provided on the left crankcase 20. [0029]
Fig. 4 is a sectional view taken along the line 4-4 of Fig. 1. The respective ends of the support protrusions 33 of the clamps 31 abut on inner surfaces of the front edge 7b of the sprocket cover 7. Among those abutting portions, on the upper and lower abutting portions, flat seat portions 44 are formed. The seat portions 44 abut on the support protrusions 33. On the abutting portion of the intermediate support
12

protrusion 33, no special seat portion is formed since the inner surface of the front edge 7b is originally substantially flat. In this manner, the abutting portions are formed of flat surfaces, thereby further ensuring support of the front edge 7b with the support protrusions 33.
[0030]
The sprocket cover 7 is fixed by the bolt 13 with a boss 45 provided on the upper portion 7d superposed on a corresponding boss 55 provided on an outer surface of the left crankcase 20. At this time, the chain guide 53 is also sandwiched between the bosses 45 and 55 to be fastened together. Also, the lower portion 7e is fixed by the bolt 14 with a boss 46 previously provided thereon superposed on a corresponding boss 56 of the left crankcase 20. At this time, a lower portion of the partition wall 42 is situated below the output sprocket 11 to abut on a side surface of the chain guide 53 also situated below the output sprocket 11, thereby separating the position sensor 16 located below the partition wall 42, and the output sprocket 11 from each other, so that adhesion to the position sensor 16 of mud, or the like, splashed from the side of the output sprocket 11 and the chain 12, is effectively prevented.
[0031]
A sensor mounting hole 57 is provided in a lower portion of the side surface of the left crankcase 20, below the output sprocket 11 and the partition plate 42, and the position sensor 16 is fitted therein to be fixed by a bolt 58. An axial end portion of a shift drum 29 is fitted in the sensor mounting hole 57. The position sensor 16 is connected to a protrusion 29a
13

provide'd at'an axial end of the shift drum 29, so that rotation of the shift drum 29 can be detected by the position sensor 16.
[0032]
Fig. 5 is an enlarged left side view of the left case cover 5 and the sprocket cover 7. The front edge 7b of the sprocket cover 7 includes an approximately half-circular arc-shaped portion with an edge facing the ACG cover 6 curved around a rear portion of the ACG cover 6, and is superposed on a rear edge of the left case cover 5. The clamps 31 overlap with the inside of an upper portion, an intermediate portion, and a lower portion of the front edge 7b.
[0033]
On the rear edge of the left case cover 5, a total of the three clamps 31 are provided leaving a predetermined space therebetween in a vertical direction. The sensor harness 15 is guided by those clamps 31 to be vertically wired substantially along the rear surface of the back wall 30. Reference numerals 35 denote bosses provided on rear edges of the left case cover for fastening the left case cover 5 to the left crankcase 20, and overlapping with the undersurface of the sprocket cover 7. Reference numeral 36 denotes another mounting boss provided on the periphery of the left case cover 5.
[0034]
The expanding portion of the ACG cover 6, the clamps 31, the bosses 35, and the like, are dislocated from center line L between the upper and lower bolts 13 and 14. Also, the upper and lower bolts 13 and 14 are positioned point-symmetrically with respect to center 0 of the output sprocket 11. With such
14

structure, even when the number of fastening portions is reduced, it is possible to easily and readily mount the sprocket cover 7.
[0035]
Further, when the sprocket cover 7 is laterally mounted on the left crankcase 20, the respective ends of the support protrusions 33 of the clamps 31 abut on inner surfaces of the front portion 7a of the sprocket cover 7. Thus, a depth of the front edge 7b of the sprocket cover 7 is regulated and positioned, and therefore assembly performance is improved. This allows improvement in workability of the assembly.
[003 6]
Also, even when the fastening points are reduced to two, by supporting the inner side of the sprocket cover 7 using the support protrusions 33 of the clamps 31 to increase strength of inward stress from outside, it is possible to sufficiently enhance support rigidity. In addition, by externally covering the sensor harness 15 with the sprocket cover 7 while guiding the sensor harness 15 with the left case cover 5, it is possible to protect the sensor harness 15 with simple structure.
[0037]
Next, a second embodiment will be described. Figs. 6 to 12 correspond to the second embodiment. Fig. 6 is a left side view of an engine; Fig. 7 is a left side view of a left crankcase; Fig. 8 is a left side view of a left case cover; Fig. 9 is a rear view of the left crankcase; Fig. 10 is a side view of a sprocket cover; Fig. 11 is a sectional view taken along the line 11-11 of Fig. 6; and Fig. 12 is a sectional view taken along ,
15

the line 1-2-12 of Fig. 6.
Here, the second embodiment also relates to wiring of a sensor harness with the left case cover and the sprocket cover of the air-cooled engine, the same as the foregoing embodiment. In the second embodiment, therefore, the component parts common with the foregoing embodiment are designated by common reference numerals, and their description is omitted except in case of necessity. [0038]
In Fig. 6, the left case cover 5 integrally includes the ACG cover 6 formed to be expanded, and is laterally fastened to the left crankcase 20 with the bosses 35 and 36. In the rear of the left case cover 5, the sprocket cover 7 is attached to the left crankcase 20 at two portions, upper and lower, with the bolts 13 and 14 to laterally cover the output sprocket 11. The front edge of the sprocket cover 7 overlaps with the rear edge of the left case cover 5, and the sensor harness 15 is vertically wired in the overlapping portion. This structure is the same as the foregoing embodiment. [0039]
As shown in Fig. 7, the left crankcase 20 includes an ACG container 60 in front, and an output sprocket container 61 in the rear. Between the ACG container 60 and the output sprocket container 61, the chain guide 53 formed in an approximately half-circular arc shape is opened rearward, and mounted to cover a front portion of the output sprocket container 61.
The sensor mounting hole 57 is provided below the left crankcase 20 and between the ACG container 60 and the chain guide
16

53. A dpindle hole 62 through which the spindle shaft passes is provided in the rear of and adjacent to the sensor mounting hold 57. [0040]
Reference numeral 63 denotes a mounting portion for the chain guide 53, and the mounting portions 63 are provided at two points, upper and lower. The upper mounting portion 63, and the boss 45 provided on the sprocket cover 7 are fastened together with the bolt 13. Reference numeral 64 denotes a boss, provided on the left crankcase 20, to which the boss 46 of the sprocket cover 7 is fastened with the bolt 14. Reference numerals 65 denote bosses, overlapping with the sprocket cover 7, of mounting bosses for the left case cover 5. Reference, numerals 66 denote other mounting bosses. [0041]
As shown in Figs. 8 and 9, the clamp 31 is integrally provided on the back wall 30 of the left case cover 5. The clamp 31 is composed of a flange 70 connecting the upper and lower bosses 35 to extend from the back wall 30 toward the output shaft 10 provided in the rear, and clamp ribs 72 and 73 provided at upper and lower portions thereof. The rear edge of the flange 70 has an approximately circular arc-shaped portion 71 curved around the chain guide 53.
The clamp ribs 72 and 73 protrude integrally upward from upper and lower portions of the flange 70, respectively. The upper edge of the clamp rib 72 as shown in Fig. 8 is placed substantially perpendicular in the vertical direction. The-upper edge of the clamp rib 73 is tilted forward so that an upper
17

portio'n of the upper edge is positionedx forward. [0042]
The clamp ribs 72 and 73 are adjacent to the upper and lower bosses 35, respectively. The upper and lower bosses 35 are fixed in a superposed manner on the upper and lower bosses 65 (Fig. 7) formed on the left crankcase 20.
The bosses 36 to be fixed in a superposed manner on the other plural bosses 66 provided on the left crankcase 20, are provided on the periphery of the left case cover 5. [0043]
As shown in Fig. 9, the clamp ribs 72 and 73 are provided at a higher position (outer side) than the bosses 35 to guide the sensor harness 15 between the back wall 30 and the clamp ribs, so that the sensor harness 15 is prevented from approaching the bosses 35. Also, the flange 70 vertically elongated is provided as the equivalent of the base portion 32 according to the foregoing embodiment. This allows the flange 70 to support the sensor harness 15 on the left crankcase 20 over a long distance, so that the sensor harness 15 can be less likely to be brought into contact with the left crankcase 20. [0044]
As shown in Fig. 10, in the center of the sprocket cover 7, the cylindrical portion 43 extending to the outer surface of the output sprocket 11 is integrally provided. Also, the partition wall 42 is integrally provided so as to surround the front of the cylindrical portion 43 in an approximately half-circular arc shape. The partition wall 42 is superposed on the chain guide 53 to form a wall for covering the front of
18

the output'Sprocket 11. [0045]
A front portion 42a of the partition wall 42 continues, with a stepped portion 42b, to a rear portion on the bosses 35, and a rear portion thereof is drawn further rearward than a virtual position extended forward, so that a certain clearance is provided between the front portion 42a and the flange 70 (Fig. 8) disposed in front of the front portion 42a. Either end of the partition wall 42 continues to the upper and lower bosses 45 and 46. With this structure, even when the partition wall 42 is elongated along the circumferential direction of the output sprocket 11, either end of the partition wall 42 is integrated with the bosses 45 and 46 having high rigidity, thereby obtaining sufficient rigidity. [0046]
On an inner surface of the front edge 7b located in front of the partition wall 42, support ribs 40a and 40b are integrally formed at upper and lower portions thereof to protrude inward. The support ribs 40a and 40b correspond to the clamp ribs 72 and 73 of the left case cover 5, respectively. The upper support rib 40a is disposed forward of the clamp rib 72, leaving a predetermined space therebetween, with approximately the same size as the clamp rib 72, and approximately parallel thereto. Also, the lower support rib 40b is disposed forward of the clamp rib 73, leaving a predetermined space therebetween, with approximately the same size as the clamp rib 72, and approximately parallel thereto. ■ [0047]
19

pis shdwn in Fig. 11, when the sprocket cover 7 is mounted, the overlap portion 41 of the front edge 7b is superposed on the flange 70, and edges of the clamp ribs 72 and 73 abut on inner surfaces of the front edge located in the rear of the support ribs 40a and 40b to thereby support the sprocket cover 7. The support ribs 40a and 40b are inserted into the clamp groove 34 formed between the clamp ribs 72 and 73, and the back wall 30 to hold the upper side of the sensor harness 15 previously stored within the clamp groove 34. ■[0048]
Further, the front edge 7b is formed with the front thereof upwardly tilted. However, since the support ribs 40a and 40b are provided in front, and the partition wall 42 is provided in the rear to support the clamp ribs 72 and 73 therebetween, rigidity of the front edge 7b is increased. Also, even in the case where the front edge 7b is formed in such a manner, deformation, such as enlargement of the opening, is avoided, and the front edge 7b is kept steady. [0049]
As shown in Fig. 12, the portion provided without the support ribs 4 0a and 4 0b of the front edge 7b covers the upper side of the flange 70 with the formation of the overlap portion 41. Since the sensor harness 15 is guided above the flange 70, the upper side of the sensor harness 15 is held by the overlap portion 41, thereby allowing falling-out prevention. In ^ addition, although no clamp rib 72 (73) is provided in the rear of the flange 70, the partition wall 42 instead of the clamp rib 72 (73) is disposed slightly rearward away from the rear
20

edge of the'flange 70, thereby allowing the sensor harness 15
to be guided from the rear of the vehicle by utilizing the
partition wall 42. ■
[0050]
As described above, according to this embodiment, it is possible to reduce the number of the support ribs 40a and 40b or the clamp ribs 72 and 73, and simplify clamp structure. Further, the sensor harness 15 can be guided over a long distance by the flange 70. Therefore, guiding is facilitated, and damage to the sensor harness 15 by the left crankcase 20 becomes less likely to be caused. In addition to this, this embodiment can achieve the same advantages as the foregoing embodiment. Also, placement of the chain guide 53 as shown in Fig. 7, the structure of the rear surface of the ACG cover 6 on the left case cover 5 as shown in Fig. 8, and the structure of the partition portion 42 as shown in Fig. 10 can be employed in the foregoing first embodiment.
[0051]
Next, a third embodiment will be described with reference to Fig. 13. Fig. 13 is an enlarged sectional view of the same portion as Fig. 3. In the third embodiment, a rear extension portion 90 is formed to protrude from the back wall 30, in a direction perpendicular to the axis of the output shaft 10 provided in the rear, in an approximately tongue shape, and a flat surface thereof faces outward. The end of the rear extension portion 90 extends to about the vicinity of a peripheral position of the output sprocket 11, and the end of an integral strut rib 47 extending, at a substantially right
21

angle,'inwardly from an inner surface of the front portion 7a, abuts on the end of the rear extension portion 90 . In this manner, the end of the strut rib 47 abuts on the rear extension portion 90 to be supported, so that the inner surface of the front portion 7a is supported by the back wall 30. Therefore, support rigidity of the front portion 7a including the front edge 7b can be still increased.
[0052]
The rear extension portion 90 corresponds to the base portion 32 and the flange 70 according to the foregoing respective embodiments. However, the rear extension portion 90 differs from those in that the rear extension portion 90 is integrally provided to protrude in an elongated manner, and in that the rear extension portion 90 is provided without the support protrusions 33, or the clamp ribs 72 and 73 with the respective ends thereof abutting directly on the inner surface of the front portion 7a. However, a protrusion formed in a short rib sjiape, or the like, may be provided to protrude from the rear extension portion 90 for allowing the respective ends of the protrusion and the strut rib 47 to abut on each other.
Here, the rear extension portion 90 is an example corresponding to a case cover extension portion of the present invention, and the strut rib 47 is an example corresponding to a cover rib of the present invention.
[0053]
With this structure, a storing space 91 for the sensor harness 15 is formed of the back wall 30, the rear extension portion 90, and the strut rib 47, and is covered with the overlap
22

portion 41 extending forward over the strut rib 47 of the front portion 7a to overlap with an upper portion of the rear extension portion 90.
Therefore, abutting of the strut rib 47 and the rear extension portion 90 allows the front portion 7a to be supported by the left case cover 5, and allows an increase in rigidity. Also, the rear extension portion 90 can be relatively downsized with a simple shape. Therefore, when the rear extension portion 90 is molded integrally with the left case cover 5, the left case cover 5 can be easily molded. [0054]
Fig. 14 illustrates a fourth embodiment with a further modification made to Fig. 13. A small rib 92 protrudes from the rear extension portion 90 toward the overlap portion 41, and a small rib 48 also protrudes from the overlap portion 41 towards the rear extension portion 90.
The respective ribs 92 and 48 are displaced from each other in a front-rear direction, leaving a space therebetween so as to prevent the ribs 92 and 48 from reaching the respective counter sides thereof and so as to prevent the ribs 92 and 48 from vertically abutting on each other, to hold the sensor harness 15 with their respective ends.
With this structure, the expanded space of the storing space 91 can be freely adjusted by changing the size or position of the two ribs 92 and 48. Even when the sensor harness 15 becomes thick or flat, therefore, the sensor harness 15 can be reliably held. '[0055]
23

'It should be understood that the present invention is not limited to the above-described embodiments. Various modifications and applications may be made within the principle of the invention. For example, any detector for detecting a state of an engine can be used instead of the position sensor 16. The harness is not only the sensor harness for the position sensor 16, but also can be variously changed according to a detector.
Further, the expanding portion of the engine case is not only the ACG cover, but also any expanding portion capable of guiding the harness can be employed.
Also, the protective cover is not necessarily limited to the sprocket cover 7. Alternatively, any cover for laterally covering the output sprocket 11 can be used. For example, a member referred to as a left rear cover, or the like, may be used. [Reference Signs List]
[0056]
1. . .Crankcase
5...Left case cover
6...ACG cover
7...Sprocket cover
10...Output shaft
11...Output sprocket
15...Sensor harness
16... Position sensor
20...Left crankcase
30...Back wall
24

31...Clamp
35...Boss
36...Boss
37...Vertical wall
38...Clamp groove
40...Rib
47...Strut rib
72, 73...Clamp rib
90...Rear expansion portion

[Document Name] Claims [Claim 1]
A cover structure for an engine, comprising:
an engine case;
an output shaft supported by the engine case;
an output sprocket co-rotatably attached to an extension portion of the output shaft protruding from the engine ca?e;
a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and
a detector supported by the engine case for detecting a state of the engine and including a harness extending outwardly from the engine, in which the engine case is externally covered with a case cover including an expanding portio'n expanding outwardly,
wherein a cover-side rib is provided for guiding the harness between the cover-side rib and the expanding portion while protruding outwardly, leaving a predetermined space from the expanding portion of the case cover, the cover-side rib abutting on and supporting an inner surface of the protective cover, and
wherein the protective cover includes an end placed between a protective cover abutting portion of the cover-side rib and the expanding portion. [Claim 2]
A cover structure for an engine, comprising:
an engine case;
an output shaft supported by the engine case;
an output sprocket co-rotatably attached to an extension

porti6n of' the output shaft protruding from the engine case;'
a protective cover attached to an outer surface of the engine case to externally cover the output sprocket; and
a detector supported by the engine case for detecting a
state of the engine and including a harness extending outwardly
from the engine, in which the engine case is externally covered
with a case cover including an expanding portion expanding
outwardly, ,
wherein a case cover extension portion is provided, the case cover extension portion extending from the case cover • toward the output shaft,
wherein the protective cover includes a cover rib protruding inward, at a predetermined spaced-apart position from the expanding portion of the engine case,
wherein the cover rib abuts on the case cover extension portion to be supported, and guides the harness between the expanding portion and the cover rib, and
wherein the protective cover includes an end placed between the cover rib and the expanding portion. [Claim 3]
The cover structure for the engine according to Claim 1 or 2,
wherein the protective cover is fastened to the engine case at a plurality of fastening portions, the fastening portions being disposed approximately point-symmetrically with respect to a center of the output shaft, and
wherein the rib provided on the case cover or on the protective cover, and the expanding portion are dislocated from

a line' between the approximately point-symmetrically disposed fastening portions. [Claim 4] ••
The cover structure for the engine according to any one of Claims 1 to 3, wherein an ACQ supported on a crankshaft is provided outwardly of the engine case, and the expanding portion of the case cover is an ACG cover for covering the ACG. [Claim 5]
The cover structure for the engine according to any one of Claims 1 to 4, wherein the detector is disposed below the output shaft, and is a position detecting sensor for detecting a rotational position of a shift drum, the position detecting sensor being externally covered with the protective cover.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=KGfwiAW7brIGZdo0QJeKcg==&loc=egcICQiyoj82NGgGrC5ChA==

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Patent Number

272513

Indian Patent Application Number

3163/CHE/2009

PG Journal Number

15/2016

Publication Date

08-Apr-2016

Grant Date

05-Apr-2016

Date of Filing

23-Dec-2009

Name of Patentee

HONDA MOTOR CO., LTD.

Applicant Address

1-1, MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO 107-8556

Inventors:

#	Inventor's Name	Inventor's Address
1	ANDO, JUNJI	C/O HONDA R&D CO., LTD., 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA 351-0193
2	HARADA, MAKOTO	C/O HONDA R&D CO., LTD., 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA 351-0193

PCT International Classification Number

B62J 13/00 ; H01H 19/20

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2009-003831	2009-01-09	Japan