JPH0861468A - Multi-stage transmission of engine - Google Patents

Abstract

PURPOSE: To improve the lubricating condition between a shift fork and a sliding groove of a gear, and between the shift fork and a shifting shaft. CONSTITUTION: A counter shaft 31 is arranged above a drive shaft 32, and a shifting shaft 38 is arranged rearward of the counter shaft 31 and the drive shaft 32, and oil injection holes 61-64 to inject the oil from the front lower part of the drive shaft 32 are provided on the part where shift forks 34-37 are slid with a sliding groove of a drive gear and with a sliding groove of a driven gear when a dog clutch is detached.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves lubrication between a shift fork and a sliding groove of a gear held by the shift fork, and between the shift fork and a shifting shaft for driving the shift fork. The present invention relates to a multi-speed transmission of an engine.

[0002]

2. Description of the Related Art An engine of a motorcycle or the like is provided with a constant mesh type multi-stage transmission. This multi-speed transmission is
A counter shaft driven by the crankshaft of the engine and a drive shaft for transmitting power to the drive wheels are provided, and a multistage gear train that constantly meshes with each other is mounted between the shafts.

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. It is provided. Further, a cylindrical cam-shaped shifting shaft for moving these shift forks is pivotally supported.

A dog clutch is provided between a specific gear in which the sliding groove is formed and another gear adjacent to this gear, and the shift fork is moved by the rotation of the shifting shaft. When a 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 the occupant of the motorcycle via the foot-operated lever.

Such a multi-stage transmission is housed in the crankcase of the engine and lubricated by the oil injected into the crankcase. That is, the oil accumulated at the bottom of the crankcase is vigorously stirred and atomized by the rotation of each gear, and the mist of this oil lubricates each part of the transmission.

[0006]

By the way, when a gear shifting operation is performed in a motorcycle, the manual clutch is temporarily disengaged so that engine torque is not applied between the gears, and then the foot-operated lever is operated to shift the gear. It is common to connect the manual clutch again and continue driving after the end of the, but for example, in some racing cars, in order to avoid the time lag due to disengaging the clutch in this way, a semi-automatic multi-stage The transmission is adopted.

The semi-automatic multi-stage transmission is designed to temporarily reduce the output of the engine during a gear shifting operation by cutting the ignition of the engine or delaying the ignition timing in association with the movement of the foot-operated lever. The engine torque applied in between is reduced to enable gear shifting operation even with the manual clutch engaged.

However, even if the engine output is temporarily reduced in this way, a strong frictional force is exerted between the shift fork and the sliding groove of the gear or between the shift fork and the shifting shaft during a gear shift operation. Therefore, the lubrication with the oil mist as described above may not be sufficient.

FIG. 8 shows the engaging portion of the dog clutch, in which the left side shows the engagement and the right side shows the disengagement.
As shown in this figure, the tooth portion of the dog clutch is formed in a tapered shape that widens toward the end, and it is difficult for the dog clutch to disengage when torque is applied between the gears.

Therefore, a strong force is required especially in the direction of disengaging the dog clutch, and as described above, the lubrication is insufficient, so that the gap between the shift fork and the sliding groove or between the shift fork and the shift fork is not sufficient. There is a risk that the frictional force between the shift shaft and the shift fork will increase and the shift fork and the sliding groove, or the sliding surface of the shifting shaft will be worn away, and in the worst case, the shift fork and the sliding groove will seize.

The present invention has been made in order to solve this problem, and is provided between the shift fork and the sliding groove of the gear.
Another object of the present invention is to provide a lubrication device for a multi-stage transmission that can improve the lubrication state between the shift fork and the shifting shaft.

[0012]

In order to achieve the above object, a multi-stage transmission of an engine according to the present invention comprises a counter shaft driven by a crank shaft of the engine, and a drive shaft transmitting power to the drive wheels. , A constantly meshing multi-stage gear train provided between both shafts and a sliding groove formed in a specific gear of this multi-stage gear train are rotatably gripped, and the gears are slid in the axial direction to be adjacent to each other. Driving a counter shaft 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 the shift fork and the gear. It is arranged above the shaft and the shifting shaft is arranged behind the counter shaft and the drive shaft, and when the dog clutch is disengaged, the shift fork is The sliding groove and is rub against part of ya,
An oil injection hole for injecting oil from the lower front of the drive shaft is provided.

[0013]

According to the multi-stage transmission of the engine constructed as described above, since the oil injected from the oil injection hole hits the portion where the shift fork and the sliding groove of the gear rub against each other when the dog clutch is disengaged, Lubrication between the fork and the sliding groove of the gear is improved.

Further, since the shifting shaft is arranged 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 the lower front of the drive shaft, the injected oil is It also hits the shifting shaft and improves the lubrication condition between the shift fork and the shifting shaft.

[0015]

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-stage transmission according to the present invention is provided in an engine.

This motorcycle 1 has its body frame 2
The front fork 4 supporting the front wheel 3 is attached to the forehead of the
The handlebar 5 and the front fender 6 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 which is provided in the vehicle width direction at a lower center of the vehicle body frame 2, and its base end portion is a suspension mechanism. Suspended by 11.

An engine 12 is mounted on the front portion of the vehicle body frame 2, and its power is transmitted through a drive sprocket 13, a chain 14, and a driven sprocket 15 to the rear wheel 8.
Is transmitted to The exhaust muffler 16 of the engine 12 extends below the engine 12 and extends rearward.

A fuel tank 17 is installed above the engine 12, and a seat 18 is placed behind the fuel tank 17. The front half of the vehicle body of the motorcycle 1 is covered by a streamlined front cowling 19 to reduce air resistance during traveling. A rear cowling 20 covers the rear part of the body frame 2.

FIG. 2 is a left side view of the engine 12. Further, FIG. 3 is an enlarged view of a part III of FIG. 2, and FIG.
FIG. 5 is a development view taken 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 in a front portion of a crankcase 22 so as to form a V-shape in a diagonally forward direction. Crankshafts 25 and 26 corresponding to the cylinders 23 and 24 are vertically supported. These two crankshafts 25 and 26 have constant speed gears that mesh with each other.
27 and 28 are fixed, the upper crankshaft 25 rotates forward (counterclockwise in FIG. 2), and the lower crankshaft 26 rotates backward.

Further, a multi-stage transmission is provided in the crankcase 22.
30 are provided. This multi-stage transmission 30 has a crankshaft
A counter shaft 31 and a drive shaft 32 which are axially supported in parallel with 25 and 26, a constantly meshed multi-stage gear train 33 provided between the shafts 31 and 32, and four shift forks 34 to 37 and It is configured to have a cylindrical cam-shaped shifting shaft 38, an oil passage 60 and oil injection holes 61 to 62 described later.

The drive shaft 32 is arranged, for example, in the lower rear part of the crankcase 22, and the counter shaft 31 is a drive shaft.
It is located above 32. Also, the above shifting shaft
38 is arranged behind the counter shaft 31 and the drive shaft 32.

A drive gear 40 is fixed to the upper crankshaft 25, and this drive gear 40 meshes with a driven gear 41 fixed to the countershaft 31, so that the countershaft 31 is driven by the crankshaft 25. And turn around. The rotation of the counter shaft 31 is performed by the drive shaft 32 through the multistage gear train 33.
To drive the drive shaft 32 forward. Drive shaft 32
Since the drive sprocket 13 is fixed on the drive shaft 32, when the drive shaft 32 rotates, power is transmitted to the rear wheel 8 which is a drive wheel.

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 gear shift type, and is composed of six drive gears A1 to A6 with different numbers of teeth mounted on the counter shaft 31 side and a drive shaft 32 side. It is composed of six driven gears B1 to B6 meshing with the drive gears A1 to A6.

Here, the drive gears A1, A3, A4,
A6 is rotationally integrated with the counter shaft 31 by spline coupling, 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 on the drive gear A3, and a sliding groove 50 is formed on the drive gear A4.
49 is rotatably held by the shift fork 34, and the sliding groove 50 is rotatably held by the shift fork 35.

The driven gears B2, B5 are rotatable integrally with the drive shaft 32 and slidable in the axial direction by spline coupling, and the driven gears B1, B3, B4, B6 are rotatable with respect to the drive shaft 32. is there. The driven gears B1 and B
Between two, between B2 and B3, between B4 and B5, B5 and B6
Dog clutches 51 to 54 are provided between them, and a sliding groove 55 formed on the driven gear B2 is formed on the shift fork 36, and a sliding groove 56 formed on the driven gear B5 is formed on the shift fork 37. , Are rotatably held.

Therefore, when the shift forks 34 to 37 are moved by the rotation of the shifting shaft 38, the drive gear A
3, A4 and driven gears B2, B5 slide in the axial direction,
The dog clutches 47 and 48 and the dog clutches 51 to 54 are engaged or disengaged. As a result, the drive gears A2 and A5 and the driven gears B1, B3, B4 and B6 that are 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 dog clutches 47 and 48.
Also, a neutral state in which the dog clutches 51 to 54 are disengaged is shown. In this state, the drive shaft 32 does not rotate even if the counter shaft 31 rotates. Further, FIG. 6 shows a state in which the drive gear A3 slides toward the drive gear A2 side by the movement of the shift fork 34 and the dog clutch 47 is engaged. In this state, the drive gear A2 is rotationally integrated 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 the engagement of 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 are formed so as to be located below the front of the drive shaft 32, and further extend from the oil passage 60 and face the multi-speed transmission 30 side (see also FIG. 4). . These oil injection holes 61 to 64 are formed so as to be orthogonal to the oil passage 60 by, for example, drilling from the outside of the crankcase 22, and after formation, the outermost parts of the oil injection holes 61 to 64 are formed by bolts 67 or the like. Is blocked.

Lubricating oil is injected into the bottom of the crankcase 22, and this oil is pumped up by an oil pump (not shown) and pumped into the oil passage 60, and the multistage transmission is transmitted through the oil injection holes 61 to 64. Oil is jetted toward 30. The oil injection directions of the oil injection holes 61 to 64 are between the sliding grooves 49 and 50 formed in the drive gears A3 and A4 of the multi-stage transmission 30 and the shift forks 34 and 35, and the driven gears B2 and 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 gears are disengaged. Sliding groove of 49,5
It is aimed at the part where 0,55,56 rub against each other.

For example, the oil injection direction of the oil injection hole 62 shown in FIG. 4 is the drive gear A3 as shown by the arrow α in FIG.
It is directed between the inner side surface 49a of the sliding groove 49 and the outer side surface 34a of the shift fork 34 which holds 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 sliding groove 49 and the outer side of the shift fork 34 are separated. The side surface 34a rubs strongly against each other, but oil is injected from the oil injection hole 62 to this portion, so that the lubrication state between the shift fork 34 and the sliding groove 49 is greatly improved, and cooling is also 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 replaced by the counter shaft 31.
Since it is located behind the drive shaft 32, oil is injected from the oil injection holes 61-64 located in the lower front of the drive shaft 32 to the shift forks 34-37 and the sliding grooves 49, 50, 55, 56. 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 that shifts gears without operating the manual clutch, the shift forks 34 to 37 and the sliding grooves 49, 50, 5 are used during shifting.
There is no risk of abrasion of the sliding surface of the shifting shaft 38 or 5,56 or seizure of the shift forks 34 to 37 and the sliding grooves 49, 50, 55, 56.

[0034]

As described above, the lubrication device for a multi-speed transmission according to the present invention includes a counter shaft driven by the crankshaft of the engine, a drive shaft transmitting power to the drive wheels, and both the shafts. It is provided between an always meshing multi-stage gear train provided between the two and an adjacent gear by gripping a sliding groove formed in a specific gear of this 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 engaging and disengaging the dog clutch, and a shift shaft for driving the shift fork, the counter shaft is arranged above the drive shaft. , A portion where the shifting shaft is arranged behind the counter shaft and the drive shaft and the shift fork and the sliding groove of the gear rub against each other when the dog clutch is disengaged. And it is characterized by comprising an oil injection hole for injecting oil from the lower front of the drive shaft.

Therefore, when the oil injected from the oil injection hole hits the portion where the shift fork and the sliding groove of the gear rub against each other when the dog clutch is disengaged, the lubrication state between the shift fork and the sliding groove of the gear is improved. To do.

Further, since the shifting shaft is arranged behind the counter shaft and the drive shaft, when the oil is injected from the front lower part of the drive shaft into the sliding groove of the shift fork and the gear, the injected oil is It also hits the shifting shaft and improves the lubrication condition between the shift fork and the shifting shaft.

[Brief description of drawings]

FIG. 1 is a left side view of a motorcycle having an engine equipped with a multi-stage transmission according to the present invention.

FIG. 2 is a left side view of the engine showing an embodiment of the present invention.

FIG. 3 is an enlarged view of a part III in FIG.

FIG. 4 is a view on arrow IV in FIG.

5 is a development view taken along the line VV of FIG. 2, showing a state in which the dog clutch is not engaged. FIG.

FIG. 6 is a development view taken along the line VV of FIG. 2, showing a state in which the dog clutch is engaged.

FIG. 7 is a detailed view around the dog clutch.

FIG. 8 is a diagram showing an engaging portion of a dog clutch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 8 Rear wheels which are drive wheels 12 Engine 22 Crankcase 23, 24 Cylinder 25, 26 Crankshaft 27, 28 Constant velocity gear 30 Multi-speed transmission 31 Counter shaft 32 Drive shaft 33 Multi-speed gear train 34-37 Shift fork 40 Drive gear 41 Driven gear 47, 48, 51, 52, 53, 54 Dog clutch 49, 50, 55, 56 Sliding groove 60 Oil passage 61-64 Oil injection hole A1-A6 Drive gear B1-B6 Driven gear

Claims (1)

[Claims] 1. A counter shaft driven by a crank shaft of an engine, a drive shaft transmitting power to a drive wheel side, a constant mesh type multi-stage gear train provided between the shafts, and a multi-stage gear train of the multi-stage gear train. The gear position is changed by rotatably gripping the sliding groove formed in a specific gear, sliding the gear in the axial direction, and disengaging the dog clutch provided between the gear and the adjacent gear. In a multi-stage transmission of an engine having a shift fork and a shifting shaft for driving the shift fork, the counter shaft is arranged above a drive shaft, and the shifting shaft is arranged behind the counter shaft and the drive shaft. However, when the dog clutch is disengaged, oil is injected from the lower front of the drive shaft to the part where the shift fork and the sliding groove of the gear rub against each other. An engine multi-stage transmission characterized by being provided with an injection hole.