JP3491347B2 - Engine multi-stage transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift fork between a shift fork and a sliding groove of a gear gripped by the shift fork, and a shift fork for driving the shift fork. TECHNICAL FIELD The present invention relates to a multi-stage transmission for an engine in which a lubrication state between the shaft and a shaft is improved. 2. Description of the Related Art An engine of a motorcycle or the like is provided with a continuously meshing multi-stage transmission. This multi-stage transmission,
It has a counter shaft driven by the crankshaft of the engine, and a drive shaft for transmitting power to the drive wheel side, and a multi-stage gear train that always meshes between the two shafts is mounted. A sliding groove is formed in a specific gear of the multi-stage gear train, and several shift forks that rotatably grip the sliding groove are movable in the axial direction of the counter shaft and the drive shaft. Is provided. In addition, a cylindrical cam-like shifting shaft for moving these shift forks is supported. [0004] A dog clutch is provided between the specific gear in which the sliding groove is formed and another gear adjacent to this gear, and the shift fork moves by the rotation of the shifting shaft. When the gear with a sliding groove is slid in the axial direction, the dog clutch is disengaged and the gear position is changed. The shifting shaft is arbitrarily operated by a motorcycle occupant via a foot-operated lever. [0005] Such a multi-stage transmission is housed in a crankcase of an engine and lubricated by oil injected into the crankcase. That is, the oil accumulated at the bottom of the crankcase is violently stirred and atomized by the rotation of each gear, and each part of the transmission is lubricated by the oil mist. [0006] By the way, when performing a gear shifting operation in a motorcycle, a manual clutch is temporarily disengaged so that torque of the engine is not applied between gears, and then a foot-operated lever is operated. It is common to connect the manual clutch again after the shift operation is completed and continue running.However, in some racing cars, for example, a semi-automatic It employs a multi-stage transmission. In a semi-automatic multi-stage transmission, the output of the engine is temporarily reduced at the time of gear shifting operation by cutting off the ignition of the engine or delaying the ignition timing in conjunction with the movement of the foot-operated lever. The gear change operation can be performed even when the manual clutch is connected by reducing the torque of the engine applied therebetween. However, even when the output of the engine is temporarily reduced, a strong frictional force is applied between the shift fork and the sliding groove of the gear or between the shift fork and the shifting shaft during the gear shifting operation. Therefore, lubrication by oil mist as described above may not be sufficient. FIG. 8 shows the engagement portion of the dog clutch. The left side in the figure shows the engaged state, and the right side shows the disengaged state.
As shown in this figure, the teeth of the dog clutch are formed in a tapered shape with a flared end so that the engagement of the dog clutch is unlikely to be released when a slight torque is applied between the gears. For this reason, a strong force is required particularly in the direction in which the dog clutch is disengaged, and the lubrication is insufficient as described above. The frictional force between the shifting shaft and the shifting shaft may increase, and the shift fork and the sliding groove, or the sliding surface of the shifting shaft may be worn out. In the worst case, the shift fork and the sliding groove may be seized. SUMMARY OF THE INVENTION The present invention has been made to solve this problem.
It is another object of the present invention to provide a lubricating device for a multi-stage transmission capable of improving a lubricating state between a shift fork and a shifting shaft. In order to achieve the above object, a multi-stage transmission for an engine according to the present invention transmits power to a counter shaft driven by a crank shaft of the engine and to a driving wheel side. A drive shaft, a constantly meshing multi-stage gear train provided between the two shafts, and a sliding groove formed in a specific gear of the multi-stage gear train are rotatably gripped, and the gear is slid in the axial direction. In a multi-stage transmission of an engine having a shift fork for changing a gear position by engaging and disengaging a dog clutch provided between adjacent gears, and a shifting shaft for driving the shift fork, the counter The shaft is arranged above the drive shaft, and the shifting shaft is arranged behind the counter shaft and the drive shaft. To strike the Tofoku a counter shaft and a sliding groove of the drive shaft each gear rubbing portion and the shifting shaft, a plurality of oil injection hole for injecting oil from the lower front of the drive shaft in the vehicle width direction, these
Car with oil injection holes at the bottom of the crankcase
It is formed so as to be orthogonal to the oil passage extending in the width direction . According to the multi-stage transmission of the engine configured as described above, the shift fork and the counter are used when the oil injected from the oil injection hole releases the dog clutch.
Since the shaft and the drive shaft contact a portion where the sliding groove of the gear rubs, the lubrication state between the shift fork and the sliding groove of the gear is improved. Further, since the shifting shaft is disposed behind the counter shaft and the drive shaft, when the oil is injected from below the front of the drive shaft into the sliding groove of the shift fork and the gear, the injected oil is The lubrication between the shift fork and the shifting shaft is also improved by hitting the shifting shaft. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a left side view of a motorcycle in which a multi-speed transmission according to the present invention is provided on an engine. The motorcycle 1 has a body frame 2
Front fork 4 supporting the front wheel 3
The handle bar 5 and the front fender 6 and the like are provided so as to be rotatable left and right. A swing arm 9 supporting a rear wheel 8 is vertically swingably connected to a pivot shaft 7 erected in the vehicle width direction at a lower center portion of the body frame 2, and its base end is a suspension mechanism. Suspended by 11 cushions. An engine 12 is mounted on a front portion of the body frame 2, and its power is transmitted via a drive sprocket 13, a chain 14, and a driven sprocket 15 to the rear wheel 8.
Is transmitted to Note that the exhaust muffler 16 of the engine 12 extends rearward below the engine 12. A fuel tank 17 is provided above the engine 12, and a seat 18 is placed behind the fuel tank 17. The front half of the motorcycle 1 is covered with a streamlined front cowling 19 to reduce air resistance during traveling. The rear portion of the body frame 2 is covered by a rear cowling 20. FIG. 2 is a left side view of the engine 12. FIG. 3 is an enlarged view of a portion III in FIG. 2, and FIG.
5 is a development view along the line VV in FIG. The engine 12 is, for example, a V-type two-cylinder two-cycle engine. Cylinders 23 and 24 are provided at the front of a crankcase 22 so as to form an obliquely forward V-shape. Crankshafts 25 and 26 corresponding to the two cylinders 23 and 24 are vertically supported. These two crankshafts 25 and 26 have constant-speed gears that mesh with each other.
The upper crankshaft 25 rotates forward (counterclockwise in FIG. 2), and the lower crankshaft 26 rotates backward. In the crankcase 22, a multi-stage transmission is provided.
30 are provided. This multi-stage transmission 30 has a crankshaft
A counter shaft 31 and a drive shaft 32 which are supported in parallel with the shafts 25 and 26; a continuously meshing multi-stage gear train 33 provided between the shafts 31 and 32; and four shift forks 34 to 37 and It has a cylindrical cam-shaped shifting shaft 38, an oil passage 60 and oil injection holes 61 to 62, which will be described later. The drive shaft 32 is disposed, for example, below the rear of the crankcase 22. The counter shaft 31 is a drive shaft.
It is located above 32. Also, the above shifting shaft
38 is disposed behind the counter shaft 31 and the drive shaft 32. A drive gear 40 is fixed to the upper crankshaft 25. Since the drive gear 40 meshes with a driven gear 41 fixed to the countershaft 31, the countershaft 31 is driven by the crankshaft 25. Turn around. The rotation of the counter shaft 31 is performed by the drive shaft 32 via the multi-stage gear train 33.
To rotate the drive shaft 32 forward. Drive shaft 32
, The drive sprocket 13 is fixed, so that when the drive shaft 32 rotates, power is transmitted to the rear wheels 8 as drive wheels. As shown in FIG. 5, the counter shaft 31 and the drive shaft 32 are rotatably supported by bearings 42 to 45. On the other hand, the multi-stage gear train 33 is, for example, a six-speed transmission type, and includes six drive gears A1 to A6 having different numbers of teeth mounted on the counter shaft 31 side and a drive shaft 32 side. It comprises six driven gears B1 to B6 that mesh with the drive gears A1 to A6. Here, the driving gears A1, A3, A4,
A6 is integrally rotatable with the counter shaft 31 by spline connection, and the drive gears A2 and A5 are rotatable with respect to the counter shaft 31. The drive gears A3 and A4 are slidable in the axial direction of the counter shaft 31, a dog clutch 47 is provided between the drive gears A2 and A3, and a dog clutch 47 is provided between the drive gears A4 and A5. 48 are provided. A sliding groove 49 is formed in the driving gear A3, and a sliding groove 50 is formed in the driving gear A4.
A shift groove 49 is rotatably held by the shift fork 34, and a sliding groove 50 is rotatably held by the shift fork 35. The driven gears B2 and B5 are rotatable and axially slidable integrally with the drive shaft 32 by spline coupling, and the driven gears B1, B3, B4 and B6 are rotatable with respect to the drive shaft 32. is there. The driven gears B1, B
2, B2, B3, B4, B5, B5, B6
Between them, dog clutches 51 to 54 are provided, and a sliding groove 55 formed on the driven gear B2 is provided on the shift fork 36, and a sliding groove 56 formed on the driven gear B5 is provided on the shift fork 37. Are rotatably held. Therefore, when each of the shift forks 34 to 37 is moved by the rotation of the shifting shaft 38, the driving gear A
3, A4 and driven gears B2, B5 slide in the axial direction,
The dog clutches 47, 48 and the dog clutches 51 to 54 are engaged or disengaged. Thus, the drive gears A2, A5 and the driven gears B1, B3, B4, B6 rotatably provided with respect to the counter shaft 31 and the drive shaft 32.
Are rotated integrally with the shaft in a predetermined order, and the gear position is changed. Then, the drive shaft 32 is driven by the counter shaft 31 via a predetermined gear ratio. FIG. 5 shows all the dog clutches 47 and 48.
And a neutral state in which the dog clutches 51 to 54 are disengaged. In this state, even if the counter shaft 31 rotates, the drive shaft 32 does not rotate. FIG. 6 shows a state in which the drive gear A3 slides toward the drive gear A2 by the movement of the shift fork 34 and the dog clutch 47 is engaged. In this state, the drive gear A2 is integrally rotated with the counter shaft 31 via the drive gear A3, so that the rotation of the counter shaft 31 is transmitted to the drive shaft 32 by meshing the drive gear A2 and the driven gear B2. As shown in FIGS. 2 and 3, an oil passage 60 extending in the vehicle width direction is provided at the bottom of the crankcase 22.
A plurality of oil injection holes 61 to 64 extending from the oil passage 60 and facing the multi-stage transmission 30 are formed (see also FIG. 4). . These oil injection holes 61 to 64 are formed so as to be orthogonal to the oil passage 60 by drilling or the like from the outside of the crankcase 22, for example. Closed. Oil for lubrication is injected into the bottom of the crankcase 22. This oil is pumped up by an oil pump (not shown) and fed into the oil passage 60, and is sent from the oil injection holes 61 to 64 to the multi-stage transmission. Oil is injected toward 30. The oil injection direction of each of the oil injection holes 61 to 64 is between the sliding grooves 49, 50 formed in the drive gears A3, A4 of the multi-stage transmission 30 and the shift forks 34, 35, and the driven gears B2, B5. It is directed between the formed sliding grooves 55 and 56 and the shift forks 36 and 37, and more specifically, when the dog clutches 47 and 48 and the dog clutches 51 to 54 are disengaged, the shift forks 34 to 37 and the gear Sliding grooves of 49,5
0,55,56 are directed to the area where they rub. For example, as shown by an arrow α in FIG. 7, the oil injection direction of the oil injection hole 62 shown in FIG.
The sliding groove 49 is directed between the inner surface 49a of the sliding groove 49 and the outer surface 34a of the shift fork 34 that grips the sliding groove 49.
In FIG. 7, when the drive gear A3 is slid in the direction of the arrow β to disengage the dog clutch 47 between the drive gears A2 and A3, the inner surface 49a of the slide groove 49 and the outer surface of the shift fork 34 Although the side surface 34a rubs strongly, the oil is injected from the oil injection hole 62 into this portion, so that the lubrication state between the shift fork 34 and the sliding groove 49 is greatly improved, and cooling is performed. Similarly, the lubrication state between the other sliding grooves 50, 55, 56 and the shift forks 35, 36, 37 is also improved. The shifting shaft 38 is connected to the counter shaft 31.
The oil is injected into the shift forks 34-37 and the sliding grooves 49, 50, 55, 56 from the oil injection holes 61-64 located in front of and below the drive shaft 32. Then, the injected oil also hits the shifting shaft 38, and the lubrication state between the shift forks 34 to 37 and the shifting shaft 38 is also improved. Therefore, even in the case of a semi-automatic multi-stage transmission in which the shift operation is performed without operating the manual clutch, the shift forks 34 to 37 and the sliding grooves 49, 50, 5
5, 56 or the sliding surface of the shifting shaft 38 is not worn out, and the shift forks 34 to 37 and the sliding grooves 49, 50, 55, 56 are not burned. As described above, the lubricating device for a multi-stage transmission according to the present invention includes a counter shaft driven by a crankshaft of an engine, a drive shaft transmitting power to a driving wheel side, and A continuously meshing multi-stage gear train provided between the two shafts and a sliding groove formed in a specific gear of the multi-stage gear train are rotatably gripped, and the gears are slid in the axial direction to be adjacent to each other. In a multi-stage transmission of an engine having a shift fork for changing a gear position by disengaging a dog clutch provided between the gear and a shifting shaft for driving the shift fork, the counter shaft is driven by a drive shaft. And the shifting axis is arranged behind the counter axis and the drive axis,
When the dog clutch is disengaged, the oil injection hole for injecting oil from the lower front of the drive shaft is provided on the vehicle so that the shift fork and the counter shaft and the sliding groove of the gear of the drive shaft rub against each other and the shifting shaft come into contact with the shift fork. Provide multiple oil jet holes in the width direction and close these oil injection holes.
An oil cover formed at the bottom of the rank case and extending in the vehicle width direction
In a direction perpendicular to the nozzle passage . Therefore, when the oil injected from the oil injection hole disengages the dog clutch, the shift fork rubs against the sliding groove of the gear of each of the counter shaft and the drive shaft, and the sliding groove of the shift fork and the gear. The lubrication state during is improved. Further, since the shifting shaft is disposed behind the counter shaft and the drive shaft, when the oil is injected into the sliding groove of the shift fork and the gear from below the front of the drive shaft, the injected oil is The lubrication between the shift fork and the shifting shaft is also improved by hitting the shifting shaft.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a left side view of a motorcycle in which a multi-speed transmission according to the present invention is provided in an engine. FIG. 2 is a left side view of the engine, showing one embodiment of the present invention. FIG. 3 is an enlarged view of a part III in FIG. 2; 4 is a view taken in the direction of the arrow IV in FIG. 3; FIG. 5 is a development view taken along a line VV in FIG. 2, showing a state in which a dog clutch is not engaged. FIG. 6 is a development view taken along a line VV in FIG. 2, showing a state in which a dog clutch is engaged. FIG. 7 is a detailed view around the dog clutch. FIG. 8 is a diagram showing an engagement portion of the dog clutch. DESCRIPTION OF SYMBOLS 1 Motorcycle 8 Rear wheel 12 as drive wheel 12 Engine 22 Crankcase 23, 24 Cylinder 25, 26 Crankshaft 27, 28 Constant-speed gear 30 Multi-stage transmission 31 Counter shaft 32 Drive shaft 33 Multi-stage gear train 34 To 37 shift fork 38 shifting shaft 40 drive gear 41 driven gears 47, 48, 51, 52, 53, 54 dog clutch 49, 50, 55, 56 sliding groove 60 oil passages 61 to 64 oil injection holes A1 to A6 drive gear B1 to B6 driven gear

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 57/00-57/12 F16H 3/00-3/78

Claims (1)

(57) Claims 1. A countershaft driven by a crankshaft of an engine, a drive shaft for transmitting power to a drive wheel side, and a constantly meshing multi-stage provided between the two shafts A dog clutch provided between a gear train and an adjacent gear by rotatably gripping a sliding groove formed in a specific gear of the multi-stage gear train and sliding the gear in the axial direction. In a multi-stage transmission of an engine having a shift fork for changing a gear position by removing the gear and a shifting shaft for driving the shift fork, the counter shaft is arranged above a drive shaft, and the shifting shaft is It is arranged behind the counter shaft and the drive shaft, and when the dog clutch is disengaged, the shift fork and the sliding grooves of the respective gears of the counter shaft and the drive shaft are rubbed. Fit portion and to strike the above shifting shaft, a plurality of oil injection hole for injecting oil from the lower front of the drive shaft in the vehicle width direction, crankcase these oil injection holes
The oil passage formed at the bottom of the case extends in the vehicle width direction.
A multi-stage transmission for an engine, which is formed so as to be orthogonal .