The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2005-287126, filed Sep. 30, 2005, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a lubrication system of a small vehicle engine wherein a crankcase having an upper case coupled to a cylinder barrel forming a cylinder bore and a lower case separably coupled thereto rotatably supports a crankshaft having an axis in the vehicle width direction, a cylinder head has at one end along the axis of the crankshaft a head side oil passage, and the lower case is provided with a supply source side oil passage communicating with an oil supply source and extended in parallel with the axis of the crankshaft and a branched oil passage guiding oil to the head side oil passage and branched from the supply source side oil passage to be erected upwardly.
2. Description of Background Art
There has been known in JP-A No. 2004-100630 a lubrication system wherein an oil passage communicating an oil filter and an oil cooler disposed on the front surface of a crankcase when an engine is mounted on a motorcycle is provided in a lower case of the crankcase along the axis of a crankshaft, and a branched oil passage branched from the oil passage guides oil to a cylinder head side.
The cylinder head is provided with a head side oil passage positioned at one end along the axis of the crankshaft. In the lubrication system disclosed in JP-A No. 2004-100630, the branched oil passage branched from the oil passage provided in the lower case is connected to the head side oil passage by an oil passage construction arranged in one plane orthogonal to the axis of the crankshaft on one end side along the axis of the crankshaft. To secure a space arranging the branched oil passage, the width of the lower case in the direction along the axis of the crankshaft needs to be set to be relatively large. The degree of freedom in arrangement of the body frame and the exhaust system mounted on a small vehicle is reduced and the bank angle is difficult to secure.
The present invention has been made in view of such circumstances and an object of the present invention is to provide a lubrication system of a small vehicle engine wherein the width of a lower case in the direction along the axis of a crankshaft can be set to be small.
To achieve the above object, according to a first aspect of the present invention, a lubrication system of a small vehicle engine wherein a crankcase having an upper case coupled to a cylinder barrel forming a cylinder bore and a lower case separably coupled thereto rotatably supports a crankshaft having an axis in the vehicle width direction, a cylinder head has a head side oil passage at one end thereof extending along the axis of the crankshaft, and the lower case is provided with a supply source side oil passage communicating with an oil supply source and extended in parallel with the axis of the crankshaft and a branched oil passage guiding oil to the head side oil passage and branched from the supply source side oil passage to be erected upwardly. An upper case side oil passage extends vertically to communicate with the head side oil passage is provided at one end of the upper case along the axis of the crankshaft. A communication passage communicating the upper end of the branched oil passage is provided in the lower case inwardly from the upper case side oil passage and extending along the axis of the crankshaft. The lower end of the upper case side oil passage is formed between coupled surfaces of the upper case and the lower case.
According to a second aspect of the present invention, a portion formed with the communication passage of the coupled surfaces of the upper case and the lower case is formed to be wider than other portions of the coupled surfaces, and a groove is formed between the coupled surfaces outwardly of the communication passage.
According to a third aspect of the present invention, a liquid gasket is applied onto the coupled surfaces of the upper case and the lower case outwardly of the groove.
An oil pump 121 of an embodiment corresponds to the oil supply source of the present invention and a sub-gallery 137 of the embodiment corresponds to the supply source side oil passage of the present invention.
Effects of the Invention
According to the first aspect of the present invention, the oil passage from the branched oil passage to the upper case side oil passage is offset from the inner side to the outer side along the axis of the crankshaft. The branched oil passage can be arranged inwardly from the lower end of the upper case side oil passage along the axis of the crankshaft. The width of the lower case in the direction along the axis of the crankshaft can be set to be relatively small. The degree of freedom in arrangement of the body frame and the exhaust system mounted on a small vehicle can be increased and the bank angle can be easily secured.
According to the second aspect of the present invention, the groove is arranged outwardly of the communication passage. The liquid sealability on the coupled surfaces of the lower case and the upper case can be further reliable.
According to the third aspect of the present invention, the projected liquid gasket is received by the groove to prevent the liquid gasket from entering into the communication passage.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
An embodiment of the present invention will be described below based on an embodiment of the present invention shown in the accompanying drawings.
In
An air cleaner 25 for cleaning air supplied to the engine E is arranged above the engine body 24 to be positioned rearwardly of the head pipe 21. A fuel tank 26 covering the rear part and the upper part of the air cleaner 25 is mounted on the both main frames 23. A radiator 27 is arranged forwardly of the engine body 24.
The rear parts of the both main frames 23 are coupled to a pair of right and left seat rails 28 extended rearwardly and upwardly. The seat rails 28 support a main seat 29 for seating a rider to the rear of the fuel tank 26. A pillion seat 30 for riding a pillion passenger is supported by the seat rails 28 in the position rearwardly away from the main seat 29.
An exhaust system 31 connected to the engine body 24 is extended downwardly from the front of the engine body 24 and is erected to be curved between a rear wheel WR and the engine body 24 from the lower side of the engine body 24 toward the right side of the vehicle body, thereby being extended rearwardly above the rear wheel WR.
The rear parts of the main frames 23 are connected to a pair of right and left pivot plates 32 extended downwardly. The front end of a swing arm 33 axially supporting the rear wheel WR at its rear end is swingably supported by the middle parts in the vertical direction of the both pivot plates 32 via an axis 34. A link mechanism 35 is provided between the lower parts of the both pivot plates 32 and the swing arm 33. The lower end of a rear cushion unit 36 whose upper end is coupled to a bracket 33a provided in the front part of the swing arm 33 is coupled to the front part of a link 37 constructing part of the link mechanism 35.
A crankcase 61 in the engine body 24 houses a transmission 72 (see later-described
The chain transmission means 41 has a driving sprocket 42 fixed to the countershaft 74, a driven sprocket 43 fixed to the rear wheel WR, and an endless chain 44 entrained about the sprockets 42 and 43, and is arranged on the left side of the engine E in the state that it is directed to the front of the traveling direction of the motorcycle.
The front of the head pipe 21 is covered by a front cowl 45 made of resin. Both sides of the front part of the vehicle body are covered by a center cowl 46 made of resin and joined to the front cowl 45. A lower cowl 47 made of resin and covering the engine body 24 from both sides is connected to the center cowl 46. The rear parts of the seat rails 28 are covered by a rear cowl 48.
A front fender 49 covering the upper side of the front wheel WF is attached to the front fork 22. A rear fender 50 covering the rear wheel WR from above is attached to the seat rails 28.
In
A crankshaft 67 having an axis in the body width direction is coupled to pistons 65 slidingly fitted in the cylinder bores 56 via connecting rods 66. The crankshafts 67 are rotatably supported by plural crank journal walls 68 provided in the crankcase 61. The crank journal walls 68 have upper walls 68a provided on the upper case 58 side mutually coupled to lower walls 68b provided on the lower case 60 side.
One end of the crankshaft 67 protruded from the crank journal wall 68 on one side (in this embodiment, the right side along the traveling direction of the motorcycle) in the axial direction of the crankshaft 67 is fitted with an overrunning clutch 69. The overrunning clutch 69 has been known and inputs to the crankshaft 67 a rotation power from a start motor 70 (see
An output of the crankshaft 67 is gear-shifted by the transmission 72 to be transmitted to the rear wheel as a driving wheel. The transmission 72 has a gear train having plural selectively-established gears between a main shaft 73 having an axis in parallel with the crankshaft 67 and rotatably supported by the upper case 58 of the crankcase 61 and a countershaft 74 having an axis in parallel with the main shaft 73 and rotatably supported between the upper case 58 and the lower case 60. The driving sprocket 42 constructing part of the chain transmission means 41 is fixed to an end of the countershaft 74 protruded from the crankcase 61.
One end of the main shaft 73 is fitted with a start clutch 75 interposed between the crankshaft 67 and the main shaft 73. When the start clutch 75 brought into the connected state according to the gear-shift operation of the rider, a power from the crankshaft 67 is transmitted to the main shaft 73.
The overrunning clutch 69 and the start clutch 75 are arranged in the positions protruded from the side walls of the cylinder block 59 and the lower case 60 (in this embodiment, the side walls on the right side toward the front of the traveling direction of the motorcycle) on one side along the axis of the crankshaft 67. A cover 76 covering the overrunning clutch 69 and the start clutch 75 is fastened to the side walls of the cylinder block 59 and the lower case 60.
Noting
With
Lifters 88 brought into contact with the top parts of the intake valves 84 are slidingly fitted in the cylinder heads 63 in the direction along the axis of the opened and closed operation of the intake valves 84. Lifters 89 brought into contact with the top parts of the exhaust valves 85 are slidingly fitted in the cylinder heads 63 in the direction along the axis of the opened and closed operation of the exhaust valves 85.
Intake side cams 90 are slidingly contacted with the lifters 88 from the opposite side of the intake valves 84. Exhaust side cams 91 are slidingly contacted with the lifters 89 from the opposite side of the exhaust valves 85. The intake side cams 90 are integral with an intake side cam shaft 92. The exhaust side cams 91 are integral with an exhaust side cam shaft 93.
The cylinder head 63 is integrally provided with the cam journal walls 94 arranged in the positions corresponding to the combustion chambers 83, which is common to the intake side cam shaft 92 and the exhaust side cam shaft 93 and a cam journal wall 95 arranged on one end side in the axial direction of the both cam shafts 92 and 93, which is common to the intake side cam shaft 92 and the exhaust side cam shaft 93. The intake side cam shaft 92 is rotatably supported by cam holders 96 and 97 fastened to the cam journal walls 94 and 95 and the cam journal walls 94 and 95. The exhaust side cam shaft 93 is rotatably supported by cam holders 98 and 97 fastened to the cam journal walls 94 and 95 and the cam journal walls 94 and 95.
With
The timing transmission device 100 has a driving sprocket 101 fixed to the crankshaft 67 between the crank journal wall 68 and the overrunning clutch 69 on one end side in the axial direction of the crankshaft 67, a driven sprocket 102 fixed to one end of the intake side cam shaft 92, a driven sprocket 103 fixed to one end of the exhaust side cam shaft 93, and an endless cam chain 104 entrained about the sprockets 101, 102, and 103. The driving sprocket 101 and the lower part of the cam chain 104 are housed between the cylinder block 59 and the cover 76. The upper part of the cam chain 104 is housed in a cam chain chamber 105 provided in the cylinder head 63 to be driven.
The loosening side of the cam chain 104, that is, the cam chain 104 between the driving sprocket 101 and the driven sprocket 102 is given a fixed tension force by a chain tensioner device 109 having a tensioner arm 106, a control arm 107, and a tensioner lifter 108.
The tensioner arm 106 has a tensioner arm body 111 swingably supported by the cylinder block 59 via a first pivot 110 near the driving sprocket 101, and a shoe 112 made of resin and attached to the tensioner arm body 111 to be slidingly contacted with the outer surface on the loosening side of the cam chain 104. The tensioner arm body 111 is formed in a belt shape by a spring steel to be curved into an arch toward the outer surface on the loosening side of the cam chain 104. The shoe 112 is formed to cover the front surface of the tensioner arm body 111.
The control arm 107 is formed by a spring steel as in the tensioner arm body 111 and has a base end swingably supported by the cylinder head 63 by a second pivot 113 near the driven sprocket 102. The swing end of the control arm 107 is brought into contact with the back surface of the swing end of the tensioner arm body 111. The back surface of the middle part of the control arm 107 is joined to a pressure receiving plate 115 via a cushion member 114 such as rubber. The tensioner lifter 108 is attached to the cylinder head 63 to exert the pressure receiving plate 115 to the tensioner arm 106 side.
The tensioner lifter 108 has been known and has a lifter case 116 fastened to the cylinder head 63, a hollow lifter rod 118 having at its edge a pressuring part 117 brought into contact with the pressure receiving plate 115 and unrotatably supported by the lifter case 116, a thread axis 119 threaded into the hollow part of the lifter rod 118, and a helical torsion spring 120 rotatably exerting the thread axis 119 in the lifter case 116 in the moving direction of the lifter rod 118.
The tensioner lifter 108 conversion-amplifies the torsional force of the helical torsion spring 120 to a thrust load by the thread axis 119. The lifter rod 118 is exerted to the control arm 107 side.
With
With
Oil is supplied from a main gallery 133 provided in the lower case 60 of the crankcase 61 to the lubrication part between the crank journal walls 68 and the crankshaft 67 and the transmission 72. The main gallery 133 is connected to the discharge port of the oil pump 121 via an oil filter 134 and an oil cooler 135. Passages 136 guiding oil to the lubrication part between the crank journal walls 68 and the crankshaft 67 are provided in the lower case 60 to communicate with the main gallery 133.
The lower case 60 of the crankcase 61 is provided with a sub-gallery 137 connected to an outlet 134a of the oil filter 134 in parallel with the main gallery 133 to guide oil to the cylinder head 63 side.
The sub-gallery 137 has a first passage part 137a linearly extended to communicate the outlet 134a of the oil filter 134 with the oil cooler 135 and a second passage part 137b linearly extended in the opposite direction of the first passage part 137a. The discharge passage 131 is connected to an inlet 134b of the oil filter 134. Oil admitted from the first passage part 137a communicating with the outlet 134a of the oil filter 134 into the oil cooler 135 is guided to the main gallery 133 via a communication passage 138 provided in the lower case 60 to coaxially communicate with an outlet 135b provided in the center part of the oil cooler 135.
The sub-gallery 137 and the main gallery 133 communicating with an outlet 135b of the oil cooler 135 have an axis in parallel with the axis of the crankshaft 67 and are provided in the lower case 60 of the crankcase 61. The discharge passage 131 has a passage part 131a provided in the lower case 60 so that one end thereof communicates with the inlet 134b of the filter 134 of the oil cooler 135, and a passage part 131b formed by a connection pipe 139 connecting the other end of the passage part 131 a and the discharge port of the oil pump 121. The passage part 131a has an axis in a plane orthogonal to the main gallery 133 and the sub-gallery 137 and is arranged below the main gallery 133 and the sub-gallery 137. The connection pipe 139 of the oil strainer 130 is bent to bypass a pipe part 130a connected to the intake port of the oil pump 121.
In
In
The outer wall surface of the lower case 60 of the crankcase 61 is provided with a circular installation seat 144 for installing a housing 143 of the oil filter 134. The circular outlet 134a communicating with the sub-gallery 137 is arranged in the center part of the installation seat 144. The inlet 134b communicating with the discharge passage 131 is arranged in the installation seat 144 in the position deviated from the outlet 134a.
An installation seat 146 for installing a housing 145 of the oil cooler 135 is provided on the outer wall surface of the lower case 60 in the position adjacent the installation seat 144 so as to form a circular recess 147. The first passage part 137a in the sub-gallery 137 is opened to the inside surface of the circular recess 147. Its opening part is the inlet 135b of the oil cooler 135. An outlet 135a is opened to the center part of the circular recess 147. The outlet 135a communicates with the main gallery 133 via the communication passage 138.
A branched oil passage 148 erected upwardly from the second passage part 137b of the sub-gallery 137 between one end of the sub-gallery 137 along the axis of the crankshaft 67 and the oil filter 134 is provided in the lower case 60 of the crankcase 61. The branched oil passage 148 communicates with the lower end of an upper case side oil passage 149 provided in the upper case 58 and the cylinder barrel 57 to be extended to the cylinder head 63 side. The upper end of the upper case side oil passage 149 communicates with the lower end of a head side oil passage 150 provided in the cylinder head 63.
The upper case side oil passage 149 is tilted upwardly toward the front of the traveling direction of the motorcycle and is provided at one end along the axis of the crankshaft 67 in the cylinder block 59 having the upper case 58 integrally coupled to the cylinder barrel 57. The branched oil passage 148 provided in the lower case 60 is extended vertically inwardly from the upper case side oil passage 149 along the axis of the crankshaft 67. The upper end of the branched oil passage 148 communicates with the lower end of the upper case side oil passage 149 via a communication passage 151 formed between the coupled surfaces of the upper case 58 and the lower case 60.
In
A portion formed with the communication passage 151 of the coupled surfaces of the upper case 58 and the lower case 60 is formed to be wider than other portions of the coupled surfaces. A groove 154 is formed outwardly of the communication passage 151 between the coupled surfaces of the upper case 58 and the lower case 60. In this embodiment, the groove 154 is formed on the coupled surface of the lower case 60 to the upper case 58.
The upper case 58 is coupled to the lower case 60 via a liquid gasket 155. The liquid gasket 155 is applied onto the coupled surfaces of the upper case 58 and the lower case 60 outwardly of the groove 154 in the portion provided with the groove 154.
The upper end of the upper case side oil passage 149 communicates with a recess 158 (see
Noting
Oil from the head side oil passage 150 is supplied to the lubrication oil passage 161 in the exhaust side camshaft 93. Oil is supplied from the lubrication oil passage 161 to the slide contact part of the exhaust side cams 91 and the lifters 89 and the slide contact part of the cam journal walls 94 and 95, the cam holders 98 and 97, and the exhaust side camshaft 93.
The ring groove 160 provided on the cam journal wall 95 and the cam holder 97 and surrounding the exhaust side camshaft 93, and a ring groove 164 provided on the cam journal wall 95 and the cam holder 97 and surrounding the intake side camshaft 92 communicate with each other by the communication groove 165 provided on at least one of the coupled surfaces of the cam journal wall 95 and the cam holder 97 (in this embodiment, the cam holder 97). A communication passage 166 communicating with the ring groove 164 is provided linearly on the cam journal wall 95 so as to be extended in parallel with the head side oil passage 150. The communication passage 166 communicates with a passage 167 provided in the lifter case 116 of the tensioner lifter 108.
The crankcases 168 are formed between plural crank journal walls 68 rotatably supporting the crankshaft 67. As shown in
A non-circular rib 170 joined endlessly by surrounding the circular communication hole 169A provided in the upper walls 68a is protruded from at least one surface of at least one part of the upper walls 68a of the crank journal walls 68. The cylinder block 69 integrally having the upper walls 68a is cast. It is difficult to provide a protrusion part on the side facing the cylinder bores 56 of the upper walls 68a. The ribs 170 and 170 are integrally protruded from the outer surfaces of the upper walls 68a and 68a arranged on the both outer sides along the axis of the crankshaft 67.
As shown in
Liners 171 insert coupled to the cylinder block 59 so as to form the cylinder bores 56 are made of a material difficult to be holed by a boring tool. When the communication holes 169A are arranged in the positions deviated from the liners 171, as clarified in
The operation of this embodiment will be described. The lower case 60 constructing the crankcase 61 together with the upper case 58 is provided with the supply source side oil passage 137 communicating with the oil pump 121 and extended in parallel with the axis of the crankshaft 67 and the branched oil passage 148 guiding oil to the head side oil passage 150 provided at one end of the cylinder head 63 along the axis of the crankshaft 67 and branched from the supply source side oil passage 137 to be erected upwardly. The upper case side oil passage 149 extended vertically to communicate with the head side oil passage 150 is provided at one end of the upper case 58 and the cylinder barrel 57 along the axis of the crankshaft 67. The upper end of the branched oil passage 148 provided in the lower case 60 inwardly from the upper case side oil passage 149 along the axis of the crankshaft 67 communicates with the lower end of the upper case side oil passage 149 via the communication passage 151 formed between the coupled surfaces of the upper case 58 and the lower case 60.
The oil passage from the branched oil passage 148 to the upper case side oil passage 149 is offset from the inner side to the outer side along the axis of the crankshaft 67. The branched oil passage 148 can be arranged inwardly from the lower end of the upper case side oil passage 149 along the axis of the crankshaft 67. A width W of the lower case 60 in the direction along the axis of the crankshaft 67 can be set to be relatively small. The degree of freedom in arrangement of the body frame F and the exhaust system 31 mounted on a small vehicle can be increased. The bank angle can be easily secured.
A portion formed with the communication passage 151 of the coupled surfaces of the upper case 58 and the lower case 60 is formed to be wider than other portions of the coupled surfaces. The groove 154 is formed between the coupled surfaces outwardly of the communication passage 151. The liquid sealability on the coupled surfaces of the lower case 60 and the upper case 58 can be further reliable.
The liquid gasket 155 is applied onto the coupled surfaces of the upper case 58 and the lower case 60 outwardly of the groove 154. The projected liquid gasket 155 is received by the groove 154 to prevent the liquid gasket 155 from entering into the communication passage 151.
The plural crank journal walls 68 rotatably supporting the crankshaft 67 are provided in the crankcase 61 to form the crankcases 168 between the crank journal walls 68. The communication hole 169A or 169B circularly formed by machining to communicate the adjacent crankcases 168 with each other is holed coaxially in the upper walls 68a of the crank journal walls 68. The non-circular ribs 170 and 170 joined endlessly by surrounding the circular communication hole 169A or 169B are integrally protruded from at least one surface of at least one part of the upper walls 68a of the crank journal walls 68, in this embodiment, from the outer surfaces of the upper walls 68a and 68a arranged on both outer sides along the axis of the crankshaft 67.
The rigidity of the upper walls 68a and 68a arranged on both outer sides along the axis of the crankshaft 67 in the crankcase 61 can be increased. The ribs 170 are formed in a non-circular shape to surround the circular communication hole 169A or 169B. Part of the periphery of at least the communication hole 169A or 169B can be spaced from the ribs 170. The substantial axial length of the communication hole 169A or 169B including the ribs 170 is shortened. The ventilation efficiency of air vented through the communication hole 169A or 169B can be increased. The pumping loss can be efficiently reduced.
The rib 170 is formed in a potbellied shape in which the small circular part 170a and the large circular part 170b are joined to each other. The position of the communication hole 169A or 169B in the rib 170 can be changed according to the requirement characteristic for each machine type. When the crankcase 61 is used for a machine type having a different requirement characteristic, the rigidity of the crankcase 61 can be secured and plural communication hole arrangement positions can be selected. The general versatility can be improved.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
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2005-287126 | Sep 2005 | JP | national |
Number | Name | Date | Kind |
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7100562 | Terada et al. | Sep 2006 | B2 |
20040069260 | Fujikubo | Apr 2004 | A1 |
20040069266 | Fujikubo | Apr 2004 | A1 |
Number | Date | Country |
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2004-100630 | Apr 2004 | JP |
Number | Date | Country | |
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20070074698 A1 | Apr 2007 | US |