JP2005069438A - Engine equipped with cartridge type transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a cartridge type transmission and shorten length in the forward and backward directions of an engine. <P>SOLUTION: This cartridge type transmission is constituted to be freely attached to and detached from a crankcase 31. A main shaft 102 is arranged on a split face BF of the crankcase 31 to pivotally support a change spindle 124 and a shift fork shaft 113 by an upper part crankcase 44 on an upper side more than the split face BF. A counter shaft 103 is pivotally supported by a lower part crankcase 45 on a lower side more than the split face BF. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine having a cartridge type transmission.

Some engines, such as motorcycles, that are internal combustion engines include a transmission that rotates a shift drum and switches a gear position by a driver's operation (see, for example, Patent Document 1). The transmission described in Patent Document 1 includes a main shaft, a counter shaft, a shift fork shaft, and a shift drum that are pivotally supported by a crankcase divided into left and right. The shift drum is disposed on the lower front side of the main shaft. The counter shaft is disposed on the lower rear side of the main shaft. The shift fork shaft is disposed below the main shaft, and the shift fork for the main shaft and the shift fork for the counter shaft are inserted into one shift fork. In addition, a change spindle serving as a swing center of a shift arm that rotates the shift drum is disposed below the shift drum.
Japanese Examined Patent Publication No. 2-29906 (5th page, Fig. 4)

However, in this type of transmission, the change spindle, shift fork shaft, shift drum, and counter shaft are concentrated on the lower side of the main shaft. Has the problem of becoming larger. In particular, as in Patent Document 1, when the shift drum, the shift fork, and the counter shaft are sequentially arranged in the front-rear direction, the length of the transmission in the front-rear direction increases, and the engine becomes larger. Furthermore, since the shift drum and the change spindle are arranged on the lower side of the engine, the layout of an oil pump or the like that supplies lubricating oil to the engine is limited.
Further, in order to configure the transmission as a cartridge type transmission that is detachable from the crankcase, it is desirable that the transmission is downsized to be easily attached and detached.
Furthermore, it is desirable that the cartridge transmission can be easily detached from the engine.
The present invention has been made in view of such a problem, and an object of the present invention is to downsize a cartridge type transmission and shorten the length of the engine in the front-rear direction.

  The invention according to claim 1 of the present invention that solves the above-described problems includes an upper crankcase (for example, the upper crankcase 44 of the embodiment) that can divide the crankcase (for example, the crankcase 31 of the embodiment) vertically. A crankshaft (for example, the crankshaft 47 of the embodiment) configured by a lower crankcase (for example, the lower crankcase 45 of the embodiment) and supported by a split surface (for example, the split surface BF of the embodiment) of the crankcase. ) And a main shaft (for example, the main shaft 102 of the embodiment), and is configured to transmit the rotational power of the main shaft to a counter shaft (for example, the counter shaft 103 of the embodiment). Removable cartridge transmission without separation (eg implementation In the engine including the cartridge type transmission 100), a change spindle (for example, the change spindle 124 of the embodiment) and at least one shift fork shaft (for example, the shift fork shaft 113 of the embodiment) are attached to the upper crankcase. An engine (for example, the engine 15 of the embodiment) including a cartridge type transmission that is supported by a shaft is used.

  In the engine equipped with this cartridge type transmission, the main shaft is disposed on the split surface of the crankcase, and the change spindle and at least one shift fork shaft are disposed above the main shaft. Since the change spindle and the shift fork and the shift function member cooperating with them, for example, the shift drum, are arranged at a high position of the crankcase, it is possible to effectively use the space that has not been used conventionally. Further, it is possible to prevent the transmission components from concentrating on the lower side of the main shaft.

  According to a second aspect of the present invention, in the engine having the cartridge type transmission according to the first aspect, the counter shaft is pivotally supported by the lower crankcase.

  In the engine equipped with this cartridge type transmission, a change spindle or the like is disposed above the split surface, and a counter shaft is disposed below the main shaft. Since the components of the transmission are arranged in the vertical direction, the length of the transmission in the front-rear direction is shortened.

  The invention according to claim 3 has a crankshaft and a main shaft that are pivotally supported by the crankcase, is configured to transmit the rotational power of the main shaft to the countershaft, and is removable in the width direction of the crankcase In an engine equipped with a cartridge type transmission, a shift arm (for example, the shift arm 122 of the embodiment) for rotating a shift drum (for example, the shift drum 105 of the embodiment) and a transmission holder (for example, an implementation) of the cartridge type transmission The engine is equipped with a cartridge-type transmission characterized in that the transmission holder 101) is arranged in the left and right directions of the vehicle.

  Since the engine equipped with this cartridge type transmission is arranged with the shift arm and the mission holder distributed to the left and right of the vehicle body, the cartridge type transmission can be attached and detached without removing the shift arm.

According to the first aspect of the present invention, since the change spindle and at least one shift fork shaft are disposed above the split surface of the crankcase, a shift drum or the like that cooperates with the change spindle and the shift fork is provided in the crankcase. Therefore, the space on the upper rear side of the engine can be effectively utilized, and the cartridge type transmission can be reduced in size. Accordingly, the transmission can be easily attached and detached, and the maintainability is improved. Further, with the downsizing of the cartridge transmission, the length of the engine in the front-rear direction can be shortened. Further, since the transmission components are not concentrated on the lower side of the main shaft, the degree of freedom in the layout of the components arranged in the lower portion of the engine is increased.
According to the invention described in claim 2, the main shaft is arranged on the upper and lower split surfaces of the crankcase, the change spindle is arranged on the upper side of the split surface, and the counter shaft is arranged on the lower side of the split surface. Therefore, the transmission components are arranged above and below the main shaft. Therefore, the longitudinal length of the cartridge transmission can be shortened. This facilitates attachment / detachment of the transmission. Since the distance from the crankshaft to the countershaft is shortened, the length in the front-rear direction of the engine can be shortened.
According to the invention described in claim 3, since the shift arm and the mission holder are arranged separately on the left and right sides of the vehicle body, the mission holder can be removed without removing the shift arm, and the cartridge transmission can be easily attached and detached. Become.

  The best mode for carrying out the invention will be described in detail with reference to the drawings. In the following, the front side is the forward direction of the vehicle, and the rear side is the direction in which the vehicle moves backward. Further, the right side and the left side are the right side and the left side in the direction in which the vehicle advances.

As shown in FIG. 1, the front wheel 2 of the motorcycle 1 is pivotally supported by a front fork 3, and the front fork 3 is steered by a head pipe 6 provided at a front end portion of a vehicle body frame 5 via a top bridge 4. It is pivoted as possible. The rear wheel 7 of the motorcycle 1 is pivotally supported by a rear fork 8, and the rear fork 8 is pivotally supported by a pivot portion 9 and an engine 15 provided at an intermediate portion of the vehicle body frame 5. In the vicinity of the pivot shaft of the rear fork 8, the upper end of the rear cushion unit 10 is attached. The lower end of the rear cushion unit 10 is attached to the lower part of the engine 15 via the link mechanism 11 and effectively absorbs the load propagating from the road surface to the vehicle body via the rear wheel 7 and the rear fork 8.
From the upper part of the head pipe 6, the main frame 12 of the vehicle body frame 5 is divided into left and right parts and extends rearward and downward, and the rear end part thereof is bent downward and continues to the pivot part 9. A seat rail 13 of the vehicle body frame 5 is connected to the rear of the main frame 12. A fuel tank 14 is disposed above the main frame 12, and an engine 15 is disposed below the main frame 12.

A driver's seat 16 and a rear passenger's pillion seat 17 are respectively supported by the seat rails 13 behind the fuel tank 14. A driver step 18 is attached to the rear portion of the pivot portion 9 of the main frame 12, and a rear passenger step 19 is attached to the lower portion of the seat rail 13. Further, a pair of left and right handles 20 are attached to the upper end portion of the front fork 3.
A brake caliper 21 is attached to the lower end of the front fork 3, and a brake rotor 22 corresponding to the brake caliper 21 is attached to the front wheel 2 to constitute a front brake device 23. A rear brake device (not shown) having the same configuration as the front brake device 23 of the front wheel 2 is provided on the right side of the rear wheel 7.
The front part of the motorcycle 1 is covered with a front cowl 24, and the periphery of the seat rail 13 is covered with a rear cowl 25. A rear sprocket 26 is attached to the left side of the rear wheel 7, and a drive chain 28 is wound around the rear sprocket 26 and a drive sprocket 27 disposed on the left side of the rear portion of the engine 15 to drive the engine driving force to the rear wheel 7. Can be communicated to. A retractable side stand 29 is disposed at the lower left side of the vehicle body frame 5 and can support the motorcycle 1 in a standing state in which the vehicle body is inclined to the left.

  The engine 15 of the present embodiment is a water-cooled in-line four-cylinder engine, and the cylinder body 30 is disposed on the crankcase 31 in a slightly inclined state. A throttle body 32 corresponding to each cylinder is connected to a rear portion of the cylinder body 30, and each throttle body 32 is connected to an air cleaner case 33 disposed between the main frame 12 and the fuel tank 14. An exhaust pipe 34 corresponding to each cylinder is connected to the front portion of the cylinder body 30. The exhaust pipe 34 curves downward from the front wall of the cylinder body 30, passes through the crankcase 31, and then bends upward at the rear of the pivot portion 9 to connect to the silencer 35 supported by the seat rail 13. Is done.

  A radiator 36 is disposed in front of the exhaust pipe 34 with a slightly forward tilted attitude similar to the cylinder body 30. The radiator 36 is a round type whose front side is curved in a concave shape, and is provided so as to extend from the upper part of the cylinder body 30 to the lower part of the crankcase 31 in the vertical direction. A pair of left and right radiator fans 39 are attached to the upper back side of the radiator 36.

  As shown in the left side view of FIG. 2 and the right side view of FIG. 3, the engine 15 includes a cylinder head 40, a cylinder block 43, and a crankcase 31 that are main components. The cylinder head 40 is divided into a head body 41 and a head cover 42, and the crankcase 31 is divided into an upper crankcase 44 and a lower crankcase 45. The upper crankcase 44 and the cylinder block 43 are integrally formed, and an oil pan 46 is attached below the lower crankcase 45. Here, the head main body 41 is a cast product made of an aluminum alloy. The split surface BF of the crankcase 31 is a surface that forms a boundary between the upper crankcase 44 and the lower crankcase 45, and is a surface that has a slope that causes the rear side to rise corresponding to the forward tilting posture of the engine 15 in a side view. .

  A spark plug 70 is screwed into the head body 41 of the cylinder head 40 so as to face each combustion chamber, and an intake port 71 and an exhaust port 72 are formed to communicate each combustion chamber with the outside. A throttle body 32 is connected to the opening on the outside of each intake port 71, and an exhaust pipe 34 is connected to the opening on the outside of each exhaust port 72. In addition, valve seats are respectively attached to the openings on the combustion chamber side of the intake ports 71 and the exhaust ports 72, and these openings can be opened and closed by the operation of the intake valves 75 and the exhaust valves 76.

  Above each intake valve 75 and exhaust valve 76, an intake side camshaft 85 and an exhaust side camshaft 86 that actuate them are arranged in parallel with the axis C of the crankshaft 47. On the peripheral surfaces of the intake side camshaft 85 and the exhaust side camshaft 86, intake side cams and exhaust side cams (not shown) corresponding to the intake valves 75 and the exhaust valves 76 are provided.

  In addition, cam sprockets (not shown) are provided at the right ends of the camshafts 85 and 86, respectively, and the camshafts 85 and 86 are linked to the crankshaft 47 through cam chains wound around the cam sprockets. . As the crankshaft 47 rotates, the camshafts 85 and 86 rotate, so that the intake valve 75 and the exhaust valve 76 can be operated. The camshafts 85 and 86 are hollow, and the hollow portion serves as a passage for engine oil (lubricating oil) L, and the engine oil L is supplied to each sliding surface from a predetermined oil hole.

  Four cylinders 50 are formed in the cylinder block 43 side by side in the vehicle body width direction. Further, pistons 51 are slidably fitted in these cylinders 50. As shown in FIG. 2, a connecting rod 53 is rotatably connected to each piston 51 via a crank pin 54, and a large end portion of the connecting rod 53 is rotatably connected to the crank pin 54 of the crankshaft 47. The reciprocating motion of the piston 51 is converted into a rotational motion about the axis C.

  As shown in FIG. 3, an oil pump 89 that pumps the engine oil L to an appropriate location in the engine 15 is disposed below the crankcase 31. The oil pump 89 is linked to an oil pump drive sprocket 128 that rotates together with the main shaft 102 of the cartridge transmission 100 via a chain 129, and starts to operate as the crankshaft 47 rotates. Engine oil L is stored in an oil pan 46 fixed to the lower part of the lower crankcase 45, and an oil strainer 130 is immersed in the stored engine oil L.

  The upper end of the oil strainer 130 is connected to the suction port of the oil pump 89, and the discharge port of the oil pump 89 is connected to a first oil passage 133 formed in the lower crankcase 45. The first oil passage 133 extends upward from the discharge port of the oil pump 89 and then bends forward, extending slightly forward and extending forward. A cartridge type oil filter 134 is detachably attached to the front wall 196 of the lower crankcase 45. The engine oil L flows into the oil filter 134 from the oil inflow path 136, flows out of the oil outflow path 137, and is guided to the water-cooled oil cooler 65.

  The above-described water-cooled oil cooler 65 is disposed substantially at the center of the front wall 196 of the crankcase 31, and an oil filter 134 is attached to the right side of the water-cooled oil cooler 65. The water-cooled oil cooler 65 is attached to the front portion of the lower crankcase 45 that constitutes the crankcase 31 and cools the engine oil L flowing through the inside with cooling water. The cooling water is introduced from an introduction hose 68 attached to the oil pump 89. The cooling water after flowing through the water-cooled oil cooler 65 and cooling the engine oil L is returned to the water pump 55 attached to the left side wall of the lower crankcase 45 through the outlet hose 67.

  The water pump 55 is attached to the left side wall of the lower crankcase 45 of the engine 15. A cooling water introduction hose 58 for introducing cooling water from the radiator 36 (see FIG. 1) and a bypass hose 64 are connected to the water pump 55. Further, the water pump 55 has a rotating shaft to which an impeller is connected, and this rotating shaft is arranged coaxially with the rotating shaft of the oil pump 89 in FIG. Therefore, the rotating shaft of the water pump 55 rotates with the main shaft 102 by the oil pump drive sprocket 128 and the chain 129 shown in FIG. 3, and the cooling water is pressurized by the impeller. The pressurized cooling water is pumped from the cooling water outlet hose 56 to the cylinder-side water jacket 57 and flows out from the cooling water outlet 61 provided in the head-side water jacket 60 at the rear of the cylinder head 40. A part of the cooling water to be pumped is supplied to the water-cooled oil cooler 65 through the introduction hose 68.

The outlet of the water-cooled oil cooler 65 is connected to a second oil passage 140 which is formed in the lower crankcase 45 and slightly rises rearward and extends rearward substantially parallel to the first oil passage 133. The second oil passage 140 communicates with an oil gallery 173 and an oil jet (not shown) in the engine 15.
The engine oil L supplied into the engine 15 is returned and stored in the oil pan 46 by natural dripping or the like. The engine oil L is supplied again into the engine 15 through the oil strainer 130, the oil pump 89, the oil filter 134, and the water-cooled oil cooler 65, and circulates in the engine 15. Note that when the engine 15 is at a high speed, the hydraulic pressure of the engine oil L being pumped increases, but when this hydraulic pressure reaches a predetermined value, a relief path is formed below the intersection of the first oil path 133 and the oil inflow path 136. The oil relief valve 142 connected via 141 is activated. A part of the engine oil L flows back into the oil pan 46, and the hydraulic pressure in the path is adjusted.

  Further, as shown in FIGS. 3 and 4, the crankcase 31 has a crankshaft 47 disposed on the front side with an axis C parallel to the vehicle body width direction, and a clutch mechanism 163 and a cartridge type transmission on the rear side. 100 is disposed. A starting system component including a starter motor 98, a reduction gear 99, and the like is disposed on the upper part of the cartridge transmission 100 so that the crankshaft 47 can be rotated when the engine is started.

  The crankshaft 47 has an axis C located on the split surface, and has a crank pin 54 that rotatably connects the connecting rod 53 of the piston 51 along the vehicle body width direction. Since the engine 15 is an in-line four-cylinder type, the crankshaft 47 includes four crankpins 54. Each crank pin 54 is supported by a pair of crank arms 169. Each crank arm 169 is integrally formed with a counterweight 169 a at a portion opposite to the crankpin 54. A balancer drive gear 187 for operating the secondary balancer 185 is provided on the outer periphery of the crank arm 169 that supports the second crank pin 54 from the left side. A primary drive gear 189 is provided on the outer periphery of the crank arm 169 that supports the fourth crank pin 54 on the rightmost side. Five journal portions 170 provided on the axis C between both ends of the crankshaft 47 and the crank arms 169 are rotatably supported by bearings 171 provided in the upper crankcase 44 and the lower crankcase 45. The A generator serving as a generator is disposed at the left end of the crankshaft 47 and is covered with a generator cover 221.

  The clutch mechanism 163 includes a primary driven gear 190 that meshes with the primary drive gear 189 of the crankshaft 47, and includes a clutch outer 191 that rotates integrally therewith. In the clutch outer 191, a clutch center 193 is splined to the main shaft 102 of the cartridge type transmission 100 and rotates integrally, and a plurality of friction plates 191 a, 193 a, 193 a on the clutch outer 191 side and the clutch center 193 side. .. And the like, and plays a role of transmitting the rotational power generated in the crankshaft 47 to the main shaft 102 of the cartridge transmission 100. A pressure plate 195 urged by a plurality of clutch springs 194 is attached to the clutch center 193, and the friction plates 191a... 193a. It becomes a state that can be transmitted.

Further, the cartridge transmission 100 will be described with reference to the schematic diagram of FIG. FIG. 5 is a view of the engine 15 as viewed from the right side, and shows a state in which the cartridge type transmission 100 is pulled out from the crankcase 31 in the removal direction indicated by the arrow D.
As shown in FIG. 5, the cartridge type transmission 100 is a cartridge type transmission that is detachably attached to a transmission case portion 92 formed with an opening 91 at the right rear portion of the crankcase 31. The cartridge type transmission 100 has a mission holder 101 that covers an opening 91, and a main shaft 102 is rotatably supported on a front upper side of the mission holder 101 via a bearing 107 (see FIG. 4). A counter shaft 103 that transmits the rotational power of the main shaft 102 is rotatably supported on the lower front side of the mission holder 101. Each of the shafts 102 and 103 is provided with a transmission gear group 104 that is spline-fitted with each other. The transmission ratio can be selected by selecting a set of transmission gears that mesh with each other from a plurality of transmission gears constituting the transmission gear group 104. Selection of the transmission gear to be meshed is controlled by a shift drum 105 rotatably passing through the rear upper side of the mission holder 101 and a plurality of shift forks operating together therewith (only the shift fork 110 is shown in FIG. 5). To do. The cartridge type transmission 100 is arranged from the inner surface of the mission holder 101 toward the left side so that the axis of each rotation shaft of the shift drum 105, the main shaft 102, and the counter shaft 103 is parallel to the axis C of the crankshaft 47. .

When the cartridge-type transmission 100 is mounted on the engine 15, that is, the transmission case portion 92, as shown in FIG. Is supported rotatably.
The left end 103a side of the countershaft 103 shown in FIG. 5 penetrates the left side wall 93 while being pivotally supported via a bearing (not shown) of the left side wall 93. A drive sprocket 27 (see FIG. 2) is spline fitted to a portion of the left end portion 103a protruding from the left side wall 93. The left end portion 108 of the shift drum 105 is pivotally supported on the left side wall 93.

The arrangement of each element when the cartridge type transmission is mounted on the engine 15 will be described with reference to FIGS.
As shown in FIG. 2, the cartridge transmission 100 is disposed at the rear portion of the crankcase 31 of the engine 15.
As shown in FIGS. 2 and 6, in the main shaft 102, the axis M of the rotation shaft is positioned on the split surface BF of the upper crankcase 44 and the lower crankcase 45 of the crankcase 31. This position is rearward along the split surface BF from the position where the crankshaft 47 is disposed. The countershaft 103 is located behind the crankshaft 47, behind the main shaft 102 and below the main shaft 102, and is axially supported by the lower crankcase 45 below the split surface BF. The shift drum 105 is substantially rearward of the main shaft 102 and has an axis R of the rotation shaft positioned behind and above the countershaft 103 and is pivotally supported by the lower crankcase 45. The axis M of the main shaft 102, the axis N of the counter shaft 103, and the axis R of the shift drum 105 are arranged in this order from the front side in plan view.

  A shift fork shaft 113 that passes through the shift fork 110 is located on the upper crankcase 44 above the split surface BF, with the axis T of the rotary shaft positioned behind and above the main shaft 102 and above and above the shift drum 105. Be supported. Further, two shift forks 111 and 112 are disposed between the shift drum 105 and the counter shaft 103, and the shift fork shaft 114 passes through both of the shift forks 111 and 112. The shift fork shaft 114 has an axis V located behind and above the counter shaft 103 and forward and below the shift drum 105, and is pivotally supported by the lower crankcase 45. The shift fork shafts 113 and 114 are both disposed closer to the shift drum 105 than the shafts 102 and 103.

  As shown in FIG. 7, the shift drum 105 has a plurality of grooves 109 on a cylindrical outer peripheral surface, and the left end portion 108 is pivotally supported on the left side wall 93 of the crankcase 31 via a bearing 115, and the right end portion 116 is pivotally supported on the mission holder 101 by a bearing 151. The groove 109 has a shape that is displaced along the direction of the axis R. The shape of the groove 109 is formed to correspond to all gear positions including neutral, and shifting is performed by moving the shift forks 110, 111, 112 engaged with the groove 109 in the direction of the axis R along the groove 109. The meshing of the gear group 104 is controlled to change the gear position. One end 110a of the shift fork 110 is engaged with the central groove 109a, and one end 111a of the shift fork 111 and one end 112a of the shift fork 112 are engaged with the grooves 109b and 109c on both sides, respectively.

  The shift fork 110 has a through hole 110b through which the shift fork shaft 113 passes. The shift fork 110 engages with one end 110a that engages with the shift drum 105 from the boss portion of the through hole 110b and with the transmission gear group 104 on the main shaft 102 side. The other end 110c is extended. The other end 110 c has a bifurcated end and engages with a groove provided in a predetermined transmission gear of the transmission gear group 104. The shift fork shaft 113 is arranged such that the axis T is parallel to the axis C of the crankshaft 47, the right end is pivotally supported by the upper crankcase 44 (see FIG. 6), and the left end is pivotally supported by the mission holder 101. The shift fork 110 is slidable along the longitudinal direction (axis line T) of the shift fork shaft 113. Therefore, when the shift drum 105 rotates and one end 110a of the shift fork 110 is pressed in the left-right direction by the groove 109a, the entire shift fork 110 moves in the left-right direction, and the transmission gear group 104 on the main shaft 102 side is moved to the main shaft. Slide along the axis M of 102.

  The shift fork 111 has a through-hole 111b through which the shift fork shaft 114 passes, and engages with one end 111a that engages the shift drum 105 from the boss portion of the through-hole 111b, and the transmission gear group 104 on the counter shaft 103 side. The other end 111c is extended. The other end 111 c has a bifurcated tip and engages with a groove provided in a predetermined transmission gear of the transmission gear group 104. Similarly, the shift fork 112 has one end 112a and the other end 112c extending from the boss portion of the through hole 112b. The axis V of the shift fork shaft 114 is arranged in parallel with the axis C of the crankshaft 47, the right end is pivotally supported by the lower crankcase 45 (see FIG. 6), and the left end is pivotally supported by the mission holder 101. The shift forks 111 and 112 are slidable along the axis V of the shift fork shaft 114 and can be moved in the left-right direction by the shift drum 105. When the shift forks 111 and 112 are moved, predetermined transmission gears that engage with the other ends 111 c and 112 c of the transmission gear group 104 on the counter shaft 103 side are slid along the axis N of the counter shaft 103.

The left end portion 108 of the shift drum 105 is rotatably supported on the left side wall 93, and a shift plate 117 is fixed to the right end surface with bolts 118. A knock pin 119 is inserted into the abutting portion between the shift plate 117 and the left end portion 108, and the shift plate 117 and the shift drum 105 can rotate together.
The shift plate 117 has a circular shape in a side view, the center thereof is fixed by a bolt 118, and six through-holes 120 are arranged at substantially equal intervals on a concentric circle. The through hole 120 is provided in parallel with the axis R of the shift drum 105, and a drum pin 121 is inserted into each of the through holes 120 from the inner side toward the outer side (left side) along the axial direction of the shift drum 105. The protruding direction of the drum pin 121 is opposite to the removing direction of the cartridge type transmission 100 indicated by the arrow D in FIG. 6, and at least one of the protruding six drum pins 121 has an engaging claw of the shift arm 122. 123 is engaged from the outside in the width direction of the engine 15 (cartridge transmission 100).

  The shift arm 122 has an elongated shape along the front-rear direction of the engine 15, and the engagement claw 123 is cut and raised toward the shift drum 105 on the rear side, and is fixed to the change spindle 124 on the front side. The change spindle 124 is rotatably supported on the upper crankcase 44 (see FIG. 6) of the left side wall 93 of the crankcase 31 and a coil-shaped shift return spring 125 is mounted. The shift arm 122 has a slit 127 above and behind the change spindle 124, and a stopper pin 126 fixed to the left side wall 93 is loosely fitted therein. One end of the shift return spring 125 is engaged with the stopper pin 126 from above, and a biasing force in the direction around the radius (the direction opposite to the arrow E in FIG. 2) is applied to the shift arm 122. ing. Since the stopper pin 126 is inserted through the slit 127 formed in the shift arm 122, the rotation amount of the shift arm 122 is regulated by the stopper pin 126.

  The change spindle 124 passes through a gear shift link cage cover 222 that covers the shift arm 122. As shown in FIG. 6, the axis S of the rotation shaft of the change spindle 124 is located above the split surface BF of the crankcase 31 and behind and above the main shaft 102. This is a position that is forward and above the shift drum 105 and partially overlaps the shift fork shaft 113 in a side view.

  As shown in FIG. 2, one end of the front side of the link member 145 is fixed to the change spindle 124. The link member 145 extends from one end to the rear along the engine 15 and is connected to the upper end of the rod 147 by a pin 146 at the other end. The lower portion of the rod 147 is coupled to a shift pedal 148 for shift change that is attached to the engine 15 so as to be swingable. A connecting portion between the lower portion of the rod 147 and the speed change pedal 148 is provided between the pin 149 serving as a swing center and an operating point where the driver puts his foot. The shift pedal 148, the rod 147, the link member 145, the change spindle 124, and the shift arm 122 are disposed on the left side of the engine 15.

  On the other hand, as shown in FIG. 7, the right end portion 116 of the shift drum 105 is rotatably supported by the mission holder 101 by a bearing 151 and penetrates the mission holder 101. A stopper plate 152 is fixed to the right end surface of the shift drum 105 with a bolt 153 so as to restrict the rotation of the shift drum 105. A knock pin 154 is press-fitted into the abutting portion between the stopper plate 152 and the right end portion 116, and the stopper plate 153 and the shift drum 105 rotate integrally.

  The stopper plate 152 has a curved groove 155 along the outer periphery, and a central portion thereof is fixed with a bolt 153. As shown in FIG. 3, the stopper plate 152 is a stopper plate that can switch the cartridge type transmission 100 in six stages, and has a substantially star shape provided with six grooves 155 in accordance with the arrangement of the drum pins 121 described above. . The stopper roller 157 of the stopper roller assembly 156 is brought into elastic contact with one of the grooves 155. As shown in FIG. 7, the stopper roller assembly 156 has a structure in which a lever member 159 is swingably attached to a bolt 158 erected from the mission holder 101, and a stopper roller 157 is rotatably attached to the tip of the lever member 159. Have. A coiled return spring 160 is attached to the bolt 158 and biases the lever member 159 in a direction in which the stopper roller 157 is pressed against the stopper plate 152.

  Further, the shift drum 105 has a cam surface 201 on the right outer peripheral portion inside the bearing 151. The cam surface 201 has protrusions (cams) 201a corresponding to all the gear positions including neutral. Further, a sensor 202 for detecting the rotational position of the shift drum 105 is attached to the wall portion 45 a of the rear portion of the lower crankcase 45 at a position corresponding to the cam surface 201. The sensor 202 is attached from the outside of the wall portion 45a, and the detection pin 203 at the front end is in contact with the cam surface 201 from a direction substantially perpendicular to the cam surface 201 (or the axis R of the shift drum 105). is there.

Next, the operation of this embodiment will be described.
When the engine 15 is started, the rotational power generated by the crankshaft 47 shown in FIGS. 3 and 4 is transmitted to the main shaft 102 of the cartridge transmission 100 via the clutch mechanism 163. The main shaft 102 is connected to the counter shaft 103 by a pair of transmission gears that are selected from the transmission gear group 104 and engaged with each other, so that the counter shaft 103 has a rotation ratio that corresponds to the gear ratio of the transmission gears of the transmission stage. Rotates. Thus, rotational power is transmitted from the main shaft 102 to the countershaft 103, and the rear wheel 7 is rotated via the drive chain 28 by the drive sprocket 27 attached to the left side of the countershaft 103 (see FIG. 1).

  Here, when the gear position is switched, the driver steps on the shift pedal 148 shown in FIG. When the shift pedal 148 is stepped downward with the pin 149 as a fulcrum, the rod 147 is pulled down substantially downward, and the link member 145 connected to the upper portion of the rod 147 with the pin 146 is lowered downward about the change spindle 124. Swing. The engaging claw 123 of the shift arm 122 integral with the change spindle 124 also swings clockwise (in the direction of arrow E in FIG. 2) about the change spindle 124. The drum pin 121 is pushed down by a predetermined amount, the shift plate 117 rotates, and the shift drum 105 fixed integrally with the shift plate 117 also rotates by an angle equal to the rotation angle of the shift plate 117.

At this time, the stopper plate 152 fixed integrally with the shift drum 105 also rotates. The stopper plate 152 pushes back the stopper roller 157 of the stopper roller assembly 156 that elastically contacts the stopper plate 152. The stopper roller 157 is pushed back along the outer peripheral surface of the stopper plate 152, and when the stopper plate 143 rotates by a rotation angle corresponding to one groove 155, the stopper roller 157 is accommodated in the rotated groove 155 by the urging force of the return spring 160. Thereby, the rotation of the stopper plate 152 and the shift drum 105 fixed integrally therewith stops.
When the driver removes his / her foot from the shift pedal 148, the shift pedal 148 returns upward. The shift arm 122 is returned in the direction opposite to the arrow E in FIG. 2 until the stopper pin 126 and the slit 127 come into contact with each other by the shift return spring 125, where it engages with the next drum pin 121.

When the shape of the groove 109 shown in FIG. 7 changes to the left and right in the axial direction, the engagement positions with the shift forks 110, 111, and 112 move in the left-right direction when the shift drum 105 rotates. For example, if the groove 109a with which the one end 110a of the shift fork 110 is engaged has a shape that is displaced to the right before and after the shift, the one end 110a of the shift fork 110 is also moved during the rotation of the shift drum 105. It is moved to the right along the groove 109a. Since the shift fork 110 is slidably supported on the shift fork shaft 113, the entire shift fork 110 moves to the right. Further, since the bifurcated portion of the other end 110c of the shift fork 110 is engaged with the transmission gear group 104 on the main shaft 102 side, the main shaft 102 that engages with the other end 110c moves to the right side. The side transmission gear also moves to the right. If the groove 109 has a shape that is displaced to the left before and after the shift, the shift fork 110 moves to the left and the transmission gear also moves to the left. If the groove 109 has a shape that does not displace in the left-right direction before and after shifting, the shift fork 110 does not move, and the transmission gear group 104 does not move.
Similarly, if the engagement positions of the shift fork 111, the shift fork 112, and the grooves 109b and 109c of the shift drum 105 change to the left and right, the shift gear group 104 on the counter shaft 103 side also moves to the right or left side accordingly. If the engagement position does not change, it does not move.

  The groove 109a, groove 109b, and groove 109c of the shift drum 105 are a groove shape that moves to the left side when the shift drum 105 rotates, a groove shape that moves to the right side, and a shift fork 110, even if the shift drum shift drum 105 rotates. A groove shape in which 111 and 112 do not move is formed in correspondence with each shift stage including neutral. Therefore, when the first speed is selected by the driver, the shift forks 110, 111, and 112 are moved according to the shapes of the grooves 109a, 109b, and 109c of the shift drum 105, and the predetermined speed change gear is brought into the meshing state. Are formed. When a shift change is made from the first speed to the second speed, the shift forks 110, 111, 112 move according to the shape of the grooves 109a, 109b, 109c of the shift drum 105 to form the first speed gear. The meshing state is released, and the transmission gears that constitute the second gear are substantially meshed at the same time.

  When removing the cartridge transmission 100 from the crankcase 31, first, the left and right crankcase covers of the engine 15 are removed. When the left crankcase cover is removed, the left end portion 103a of the countershaft 102 appears, and the drive sprocket 27 (see FIG. 2) fixed thereto is removed. On the other hand, when the right crankcase cover is removed, the clutch mechanism 163 appears, which is removed to expose the mission holder 101. Next, the bolts on the outer periphery of the mission holder 101 are removed, the mission holder 101 is pulled out along the arrow D in FIG. 5, and the cartridge transmission 100 is removed from the crankcase 31. At this time, the main shaft 102, the counter shaft 103, and the shift drum 105 that are pivotally supported by the mission holder 101 are also pulled out from the crankcase 31. Since the stopper plate 152 and the stopper roller assembly 156 are arranged on the mission holder 101 side, they are pulled out together with the mission holder 101. Similarly, the shift plate 117 on which the drum pin 121 is mounted is pulled out from the crankcase 31 together with the shift drum 105. On the other hand, the shift arm 122 engaged with the drum pin 121 remains on the crankcase 31 side (see FIG. 6).

  When the cartridge type transmission 100 is attached to the crankcase 31, the mission holder 101 is inserted into the mission case portion 92 of the crankcase 31 as shown in FIGS. 4 and 5. At this time, the shift plate 117 penetrates the left side wall 93 of the mission case portion 92, and the drum pin 121 engages with the engagement claw 123. In this state, the mission holder 101 is fixed to the crankcase 31 with a bolt, and the clutch mechanism 163 is attached to the right end portion 102b (see FIG. 5) of the main shaft 102 that protrudes to the right from the mission holder 101. On the other hand, since the countershaft 103 protrudes on the left side of the engine 15, the drive sprocket 27 is fixed thereto. After that, attach the left and right crankcase covers. Thus, the cartridge transmission 100 can be removed without separating the crankcase 31 from the split surface BF.

  As shown in FIGS. 2 and 6, in the present embodiment, in the engine 15 including the cartridge type transmission 100, the main shaft 102 is disposed on the split surface BF of the crankcase 31, and above the split surface BF. The change spindle 124 and the shift fork shaft 113 are supported. By disposing the change spindle 124 and the shift fork shaft 113 in the space on the upper rear side of the main shaft 102 that has not been used conventionally, the empty space can be effectively utilized. Further, the shift spindle 124 and the shift fork shaft 113, and the shift functional parts including the shift drum 105, the shift fork 110, the shift arm 122, and the like cooperating with the change spindle 124 and the shift arm 122 are arranged at a high position of the crankcase 31, so the main shaft The degree of freedom of the layout below 102 is improved. Furthermore, the cartridge type transmission 100 can be made compact by optimizing the arrangement of the shift function parts. Therefore, the length of the engine 15 in the front-rear direction can be shortened.

  Further, since the shift arm 122 and the mission holder 101 are arranged in the left-right direction of the engine 15, the mission holder 101 can be removed without removing the shift arm 122. Therefore, the cartridge type transmission 100 can be easily attached and detached, and the maintainability is improved.

  Furthermore, while the change spindle 124 and the like are disposed above the main shaft 102, the counter shaft 103 is disposed in the lower crankcase 45 below the main shaft 102. Since the components of the cartridge transmission 100 are arranged above and below the main shaft 102, the length in the front-rear direction is further shortened, and the length in the front-rear direction of the engine 15 is shortened. In addition, maintainability is further improved.

The present invention is not limited to this embodiment. For example, the cartridge type transmission 100 is not limited to a two-wheeled vehicle, but may be a transmission such as a three-wheeled vehicle, a four-wheeled vehicle, or a ship.
The split surface BF of the crankcase 31 may not have an inclination, and may have an inclination in which the front side rises with respect to the rear side. The same effect can be realized even if the shift drum 105 is pivotally supported on the upper crankcase 44 side of the crankcase 31. Similarly, the shift fork shaft 114 may be pivotally supported on the upper crankcase 44 side.

1 is a side view of a motorcycle according to an embodiment of the present invention. It is a left view of an engine. It is a right view of an engine. It is sectional drawing along the AA line of FIG. It is a schematic diagram explaining attachment and detachment of a cartridge type transmission. It is a right side view of the engine, and is an enlarged view for explaining the arrangement of the cartridge transmission. It is an expanded view which shows a shift drum.

Explanation of symbols

15 Engine 31 Crankcase 44 Upper crankcase 45 Lower crankcase 47 Crankshaft 100 Cartridge type transmission 101 Transmission holder 102 Main shaft 103 Countershaft 105 Shift drum 113 Shift fork shaft 122 Shift arm 124 Change spindle BF Split face

Claims (3)

The crankcase is composed of an upper crankcase and a lower crankcase that can be divided into upper and lower parts, and has a crankshaft and a main shaft that are pivotally supported by a split surface of the crankcase, and the rotational power of the main shaft is used as a countershaft. In an engine having a cartridge-type transmission configured to transmit and removable without separating the crankcase,
An engine having a cartridge-type transmission, wherein a change spindle and at least one shift fork shaft are pivotally supported by the upper crankcase.   2. The engine having a cartridge type transmission according to claim 1, wherein the counter shaft is pivotally supported by the lower crankcase. An engine having a crankshaft supported by a crankcase and a main shaft, and configured to transmit the rotational power of the main shaft to a countershaft and having a cartridge-type transmission that is removable in the width direction of the crankcase In
An engine equipped with a cartridge type transmission, wherein a shift arm for rotating a shift drum and a transmission holder of the cartridge type transmission are arranged separately on the left and right sides of the vehicle.

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