Title of Invention

AIR CLEANER IN MOTORCYCLE

Abstract

In a motorcycle having an air cleaner 84 above a cylinder head 13 of an engine 12, a recess 98 is formed in the air cleaner 84 so as to overlap an extension line 97 of an axis 78 of a spark plug 75 installed in the cylinder head 13 and so that a tool for removing the spark plug 75 can be inserted into the recess 98 on the extension line 97 of the spark plug axis 78, thereby facilitating removal of the spark plug 75.

Full Text

[Name of Document] Specification [Title of the Invention] Air Cleaner in Motorcycle [Technical Field] [0001] The present invention relates to an improvement of an air cleaner in a motorcycle. [Background Art] [0002] A conventional air cleaner in a motorcycle is known which is disposed above an engine (see, for example, Patent Document 1). [Patent Document 1] Japanese Patent No. 2854964 [0003] Reference will be made below to Fig. 3 in Patent Document 1. In the motorcycle illustrated in the Fig. 3, an engine 11 is disposed within a double cradle-shaped frame 1 and an air cleaner 18 is disposed above the engine 11, further, a cylinder block 12 and a cylinder head 14 of the engine 11 are in a forwardly inclined state with respect to a vertical line. [Disclosure of the Invention] [Problem to be Solved by the Invention] [0004] If the angle of forward inclination of the cylinder block 12 and the cylinder head 14 is small, the air cleaner 18 becomes an obstacle when a spark plug installed in the cylinder head 14 is to be removed upwards of the engine 11, and thus the maintainability of the spark plug is affected. [0005] It is an object of the present invention to improve an air cleaner in a motorcycle and thereby improve the maintainability of a spark plug. [Means for Solving the Problem] [0006] According to the invention defined in claim 1, in a motorcycle having an air cleaner above a cylinder head of an engine, a recess is formed in the air cleaner so as to overlap an extension line of an axis of a spark plug installed in the cylinder head to facilitate removal of the spark plug. [0007] A tool for removing the spark plug is inserted into the recess of the air cleaner so as to lie on an extension line of the spark plug axis and is attached to the spark plug to facilitate removal of the spark plug or mounting of the spark plug after removal. [0008] The invention defined in claim 2 is characterized in that the air cleaner is mounted to a pair of frames and the axis of the spark plug lies between the pair of frames. Since the axis of the spark plug is positioned between the pair of frames, the spark plug removing tool does not interfere with the pair of frames when removing the spark plug. [0009] The invention defined in claim 3 is characterized in that an intake duct of the air cleaner is offset to one side of the air cleaner so as not to overlap the extension line of the spark plug. By offsetting the intake duct of the air cleaner to one side of the air cleaner so as not to overlap the extension line of the spark plug, there is ensured a space disposing the spark plug removing tool on the extension line. [Effects of the Invention] [0010] According to the invention defined in claim 1, since a recess is formed in the air cleaner so as to overlap an extension line of the axis of the spark plug installed in the cylinder head, the spark plug can be removed easily without being obstructed by the air cleaner and the maintainability of the spark plug can be improved. [0011] According to the invention defined in claim 2, since the axis of the spark plug is positioned between a pair of frames, the spark plug can be removed easily without interference of the spark plug removing tool with the pair of frames. [0012] According to the invention defined in claim 3, since an intake duct of the air cleaner is offset to one side of the air cleaner so as not to overlap the extension line of the spark plug, the spark plug removing operation can be done without being obstructed by the intake duct and thus the maintainability of the spark plug can be improved. [Best Mode for Carrying out the Invention] [0013] The best mode for carrying out the present invention will be described hereinunder with reference to the accompanying drawings. The drawings should be seen in the directions of the reference numerals. Fig. 1 is a side view of a motorcycle related to the present invention. In the motorcycle, indicated at 10, a water-cooled engine 12 is disposed inside a body frame 11 which is in the shape of a double cradle, an intake system 14 is mounted to a rear portion of a cylinder head 13 of the engine 12, and an exhaust system 16 is mounted to a front portion of the cylinder head 13. [0014] The body frame 11 includes a head pipe 21, a pair of right and left main pipes 22, a pair of right and left center pipes 23 integral with a rear portion of the right and left main pipes 22, a pair of right and left down-pipes 24, a pair of right and left seat rails 26, a pair of right and left sub-pipes 27, and a pair of right and left pivot plates 2 8 mounted to the right and left center pipes 23. [0015] The numeral 31 denotes a font fork secured to the head pipe 21 steerably, numeral 32 denotes a front wheel, numeral 3 3 denotes a front fender, numeral 34 denotes a bar handle, numeral 3 6 denotes a radiator mounted to the down-pipes 24, numeral 37 denotes a fuel tank, numeral 38 denotes a fuel pump installed within the fuel tank 37, numeral 41 denotes an upper cover which covers the intake system 14 and the fuel tank 26 from above, numeral 4 2 denotes a seat, numeral 4 3 denotes a side cover, numeral 44 denotes a swing arm connected swingably to each of the right and left pivot plates 28, numeral 46 denotes a rear wheel, numeral 4 7 denotes a rear fender, numeral 4 8 denotes a step for a rider, numeral 51 denotes a step for a passenger, numeral 52 denotes a step bracket attached to each of the center pipes 23 for supporting the rider step 48 and the passenger step 51, numeral 53 denotes a side stand, and numeral 54 denotes a rear cushion unit for buffer connected bridgewise to both the main pipe 22 side and the swing arm 44. [0016] Fig. 2 is a side view (partially in section, the arrow FRONT in the figure represents the front side of the vehicle, as is also the case in the other drawings) of principal portions of the motorcycle related to the present invention. The engine 12 includes a cylinder block 63 with a piston 62 inserted movably into a cylinder bore 61, a cylinder head 13 mounted on top of the cylinder block 63, and a head cover 64 which closes an upper portion of the cylinder head 13. [0017] The cylinder head 13 includes an intake valve 67 for opening and closing an intake port 66, an exhaust valve 71 for opening and closing an exhaust port 68, cam shafts 72 and 73 for actuating the intake valve 67 and the exhaust valve 71, respectively, and a spark plug 75 having a tip projecting into a combustion chamber 74 which communicates with the intake port 66 and the exhaust port 68. [0018] Numeral 76 denotes a hole to be used for connecting an ignition coil to the spark plug 75 or for removal and maintenance of the spark plug, numeral 77 denotes a tubular member mounted bridgewise between the cylinder head 13 and the head cover 64 to form the hole 6, and numeral 78 denotes the axis of the spark plug 75. [0019] The intake system 14 is made up of a throttle body 82 connected at one end to an intake system connecting portion 81 which is provided in the cylinder head 13, a connecting tube 83 connected to an opposite end of the throttle body 82, and an air cleaner 84 connected to the connecting tube 83 . The connecting tube 83 extends up to the interior of the air cleaner 84. Numeral 86 denotes a fuel injection valve attached to the throttle body 82. [0020] The air cleaner 84 is made up of an air cleaner case 91 and an air cleaner element 92 disposed within the air cleaner case 91. The air cleaner case 91 is made up of a case body 94 and an air cleaner cover 95 which closes an opening of the case body 94. [0021] The case body 94 includes a recess 98 formed so as to overlap an extension line 97 of the axis 78 of the spark plug 75 and an intake duct 101 substantially projecting forward. Numeral 101a denotes an opening as an intake port formed in a front end of the intake duct 101. The recess 98 is formed in such a manner that a bottom 98a thereof is nearly parallel to the extension line 97. A pair of numerals 98b (only the inner-side numeral 98b is shown) denote side faces of the recess 98. [0022] The exhaust system 16 is made up of an exhaust pipe 106 connected at one end thereof to an exhaust system connecting portion 105, a heaterless 02 sensor attached to the exhaust pipe 106 at a position near the connection thereof to the cylinder head 13, and a muffler 108 attached to a rear end of the exhaust pipe 106 as shown in Fig. 1. Numeral 111 denotes a muffler support member attached to the step bracket 52 for supporting the muffler 108. [0023] In Fig. 2, the radiator 3 6 is mounted to front portions of the right and left down-pipes 24. A cooling fan 113 for feeding air forcibly to the radiator 36 is mounted through a bracket to a rear portion of the radiator 36. The heaterless O2 sensor 107 is mounted on top of the exhaust pipe 106 at a position between the radiator 36 and the cylinder head 13. [0024] The heaterless O2 sensor 107 is for detecting the concentration of oxygen contained in exhaust gas and does not include a heater for heating. For example, a heater-containing O2 sensor is of a structure wherein a sensor portion is heated by supplying an electric current to the heater to shorten the heat-up time up to a temperature required for operation of the sensor portion. This structure causes an increase of cost and of power consumption of a battery. On the other hand, in the case of the heaterless 02 sensor 107, since it does not have a heater, it is possible to decrease the cost and keep the power consumption of the battery low. [0025] Further, since the heaterless O2 sensor 107 is attached to the exhaust pipe 106 in the vicinity of the connection to the cylinder head 13 (i.e., disposed at a position closer to the combustion chamber 74), it is possible to raise the temperature up to the operation temperature of the sensor 107 in a short time. [0026] That is, the temperature of the heaterless 02 sensor 107 can be made relatively high and hence it is possible to quicken the activation of the sensor 107. An oxygen concentration signal is fed from the heaterless O2 sensor 107 to an engine control unit (not shown), which in turn performs a fuel injection control in accordance with the oxygen concentration signal. In this way it is possible to improve the engine output and improve the condition of exhaust gas. [0027] Fig. 3 is a plan view of principal portions of the motorcycle related to the present invention, showing a state in which a pair of right and left main pipes 22 are extended backward of the vehicle body from the head pipe 21, an air cleaner 84 is mounted to upper portions of the main pipes 22, a recess 98 is formed in a front portion of the air cleaner case 91 of the air cleaner 84 so as to overlap a vehicle body center line 120 extending the longitudinal direction of the vehicle body, and an intake duct 101 is disposed on one side of the vehicle body center line 12 0, i.e., in an offset state to the right, and so as to extend substantially in the longitudinal direction. Since the intake duct 101 is offset to one side with respect to the recess 98, there is no fear of the intake duct 101 being an obstacle when inserting the spark plug removing tool into the recess 98. [0028] The reason why the intake duct 101 is offset to the right side with respect to the vehicle body center line 12 0 and the recess 98 is that the air which has warmed up with heat of the exhaust pipe 106 disposed offset to the left side with respect to the vehicle body center line 120 is to be made difficult to be sucked in from the intake duct 101. [0029] Numeral 123 denotes a reinforcing plate connected bridgewise to front portions of the right and left main pipes 22, a pair of numerals 124 denote front projecting portions projecting forward from the air cleaner case 91 to mount the air cleaner 84 to the main pipes 22, a pair of numerals 126 (only one numeral 12 6 is shown) denote bolts for fixing the front projecting portions 124 to the reinforcing plate 123, numeral 127 denotes a radiator cap, numerals 128 and 131 denote radiator hoses, numerals 133 and 134 denote a cross plate and a cross pipe, respectively, which are connected bridgewise to the rear portions of the right and left main pipes 22, and numeral 13 6 denotes a cushion upper end supporting bracket attached to both cross plate 133 and cross pipe 134 to support an upper end of the rear cushion unit 54 (see Fig. 1) . [0030] Fig. 4 is a sectional view of the air cleaner embodying the present invention. The air cleaner case 91 of the air cleaner 84 is a vessel the interior of which is divided into a dirty side (a space in which unpurified intake air is present) 141 and a clean side (a space in which purified intake air is present) 142 by means of an air cleaner element 92. The intake duct 101 is in communication with the dirty side 141, while the connecting tube 83 is in communication with the clean side 142. [0031] The case body 94 of the air cleaner case 91 includes an element receptacle 144 for receiving the air cleaner element 92 therein and a fitting hole 145 for fitting therein of the connecting tube 83. Numeral 83a denotes a throttle body connection for connection thereto of the throttle body 82 (see Fig. 2), numeral 94a denotes a rear mounting portion which integral with a rear portion of the case body 94 to mount the air cleaner 84 to the main pipes 22 (see Fig. 2), numeral 94b denotes a drain pipe for the discharge of dust and water separated from the intake air within the dirty side 142, and numeral 14 6 denotes a drain hose attached to the drain pipe 94b. [0032] The air cleaner element 92 is made up of a frame member 147 and a filter (a cross-hatched portion) 148 secured to the frame member 147. The air cleaner element 92 is received in the element receptacle 144 of the case body 94, a spacer 151 is attached to the air cleaner cover 95, and the air cleaner cover 95 is aligned with and secured to the case body 94. In this way the air cleaner element 92 is fixed while being urged by the spacer 151. [0033] The outside air passes through the intake duct 101 from the opening 101a of the intake duct, flows into the dirty side 141, passes through the filter 148 and reaches the clean side 142, then flows through the connecting tube 83 into the throttle body and the combustion chamber of the engine. The recess 98 is a portion formed by depressing a front wall 94c of the dirty side 141 and it can be formed easily when forming the case body 94 by molding. [0034] Next, a description will be given below about how to remove the spark plug 75 described above. Figs. 5(a), 5(b) are operation diagrams showing how to remove the spark plug related to the present invention. In Fig. 5(a), a tool 155 (hereinafter referred to as the plug wrench 155) for removing the spark plug 75 is moved from the front side of the air cleaner 84 (front-and lower-side walls of the air cleaner 84 are hatched) onto the extension line 97 within the recess 98, as indicated with arrow A, and is further moved into the hole 76 formed in the upper portion of the engine 12, as indicated with arrow B. One end portion 155a and an opposite end portion 155b of the plug wrench 155 are each provided with a hexagonal hole. Numeral 75a denotes a hexagonal portion of the spark plug 75. [0035] In Fig. 5(b), the hexagonal hole formed in one end portion 155a of the plug wrench 155 is fitted on the hexagonal portion 75a of the spark plug 75. Then, a hexagonal tip 156a of a ratchet handle 156 as a hand-working tool is inserted into the hexagonal hole formed in the opposite end portion 155b of the plug wrench 155, as indicated with arrow C, and the spark plug 75 is turned with the ratchet handle 156 through the plug wrench 155 to remove the spark plug 75 from the cylinder head 13. Mounting of the spark plug 75 is performed in reverse order from the above mounting order. [0036] As described above in connection with Figs. 1 and 2, in the motorcycle 10 having the air cleaner 84 above the cylinder head 13 of the engine 12, the present invention is characterized in that the recess 98 is formed in the air cleaner 84 so as to overlap the extension line 97 of the axis 78 of the spark plug 75 installed in the cylinder head 13, thereby facilitating removal of the spark plug 75. [0037] Since the recess 98 is formed in the air cleaner 84 so as to overlap the extension line 97 of the axis 7 8 of the spark plug 75 installed in the cylinder head 13, the spark plug 75 can be removed easily without being obstructed by the air cleaner 84 even if the angle of forward inclination of the cylinder head 13 and cylinder block 63 in the engine 12, whereby it is possible to improve the maintainability of the spark plug 75. Further, since the angle of forward inclination of the engine 12 is small, it is possible to shorten the distance between the engine 12 and the front wheel 32 and hence possible to shorten the wheel base of the motorcycle 10. [0038] As shown in Figs. 2 and 5 (a), 5(b) , the present invention is also characterized in that the air cleaner 84 is mounted to the main pipes 22 (see Fig. 3) as a pair of frames and that the axis 78 of the spark plug 75 and the extension line 97 thereof are positioned between the pair of main pipes 22. [0039] Since the axis 78 of the spark plug 75 and the extension line 97 thereof are positioned between the pair of main pipes 22, the spark plug 75 can be removed easily without interference of the plug wrench 155 as a spark plug removing tool and the ratchet handle 156 with the pair of main pipes 22. [0040] As shown in Fig. 3, the present invention is further characterized in that the intake duct 101 of the air cleaner 84 is offset to one side of the air cleaner 84, more particularly, to one side of the recess 98 (the right side of the vehicle body center line 120) so as not to overlap the extension line 97 (see Fig. 2) of the spark plug 75 (see Fig. 2) . [0041] As a result, the spark plug 75 can be removed without being obstructed by the intake duct 101 and hence it is possible to improve the maintainability of the spark plug 75. [Industrial Applicability] [0042] The air cleaner of the present invention is suitable for a motorcycle. [Brief Description of the Drawings] [0043] [Fig. 1] Fig. 1 is a side view of a motorcycle related to the present invention. [Fig. 2] Fig. 2 is a side view of principal portions of the motorcycle. [Fig. 3] Fig. 3 is a plan view of principal portions of the motorcycle. [Fig. 4] Fig. 4 is a sectional view of an air cleaner embodying the present invention. [Fig. 5] Fig. 5 is an operation diagram showing how to remove a spark plug related to the present invention. [Description of Reference Numerals] [0044] 10 ... motorcycle, 12 ... engine, 13 ... cylinder head, 22 ... frame (main pipe), 75 ... spark plug, 78 ... axis of the spark plug, 84 ... air cleaner, 97 ... extension line of the axis of the spark plug, 98 ... recess, 101 ... intake duct.

Documents:

1285-che-2006 abstract granted.pdf

1285-che-2006 claims granted.pdf

1285-che-2006 description (complete) granted.pdf

1285-che-2006 drawings granted.pdf

1285-che-2006-abstract.pdf

1285-che-2006-abstractimage.jpg

1285-che-2006-claims.pdf

1285-che-2006-correspondence-others.pdf

1285-che-2006-description-complete.pdf

1285-che-2006-drawings.pdf

1285-che-2006-form 1.pdf

1285-che-2006-form 18.pdf

1285-che-2006-form 26.pdf

1285-che-2006-form 3.pdf

1285-che-2006-form 5.pdf

1285-che-2006-priority document.pdf