JPH10331864A - Creep prevention device for multiple disc clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a creep prevention device simple in structure, and excellent in durability by matching a braking unit simple in structure with the driven side of a clutch. SOLUTION: Both an inner race 20 connected with a driving shaft 12 and an outer race 30 connected with a driven shaft 13, are housed in a clutch case 11, a pressing plate 21 supported by the inner race 20 is interposed between a pressure receiving disc 32 supported by the outer race 30 and a pressing disc 31, the pressing disc 31 is energized to the pressure receiving disc side by an engaging spring 17 interposed between the pressure receiving disc 32 and the outer race 30, concurrently a clutch cam is provided for the end part of the outer race 30, which presses the outer race 30 against the engaging spring 17 so as to retreat the pressing disc 31, and let a restraining plate 50 only the rotating direction of which is locked to the clutch case 11, be interposed between the clutch cam and the end part of the outer race 30, so that its driven side is thereby restrained while releasing operations are being carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-plate clutch suitable for agricultural tractors, and more particularly to a method and apparatus for preventing so-called creep, in which a slight torque is transmitted when the clutch is released.

[0002]

2. Description of the Related Art Conventionally, in a wet multi-plate clutch, a small driving force is transmitted from a drive shaft to a driven shaft even when the clutch is released by the action of lubricating oil for lubricating the pressure plate, so that the driven side is driven at a low speed. This phenomenon is known as creep. Further, in order to prevent creep, a spring is interposed between the pressure plate for pressing the pressure plate and the pressure receiving plate to forcibly separate the pressure plate, but the number of pressure plates of the multi-plate clutch increases. There was a problem that the effect was diminished. On the other hand,
The technique of forcibly stopping the driven side when the friction clutch is released is frequently used in a steering brake used when turning the traveling direction of a cultivator or a tractor. That is, in the turning brake, the same level of power transmission capability is given to the clutch that interrupts the power and the brake that brakes the driven wheel side. In other words, the same size is prepared.

[0003]

However, if a simple multi-plate clutch is provided with braking means similar to a steering brake, the structure becomes complicated and the device becomes large.

[0004]

The object of the present invention is to provide a clutch case in which an inner race connected to a drive shaft and an outer race connected to a driven shaft are housed in a clutch case, and a pressure supported by the inner race between a pressure receiving plate and a pressing plate supported by the outer race. A plate is disposed, and the pressing plate is urged toward the pressure receiving plate by an engagement spring disposed between the pressure receiving plate and the outer ring,
A clutch cam that presses the outer ring against the engagement spring and retreats the pressing plate is provided at an end of the outer ring, and the clutch case is locked only in the rotation direction between the clutch cam and the end of the outer ring. The problem is solved by interposing a stop plate. Further, it is preferable that a friction material is attached to one of the outer race and the stop plate. Further, a hard sintered alloy is preferable as the friction plate.

[0005]

The drive shaft and the driven shaft hold the pressure plate supported by the inner ring between the pressing plate and the pressure receiving plate provided on the outer ring, and pressurize by an engagement spring to enable frictional transmission of power. Also,
When the clutch cam is operated to press the outer ring and retreat the pressing plate, the frictional engagement between the friction plate provided on the outer ring and the pressure plate is released, and the transmission of power is cut off. A stop plate locked to the clutch case is interposed between the outer ring and the clutch cam, and when the clutch cam is operated, the outer ring and the clutch case frictionally engage to stop rotation of the outer ring. Since a friction material made of a hard sintered alloy is attached to either the outer ring or the stopping plate, while the outer ring is stopped by the locking plate, while the excessive drag torque is acting,
Between them, they moderately slide to reduce the impact given to the driven side.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 10 denotes a multi-plate wet friction clutch. The friction clutch 10 has a clutch case 11 in which two halves separated in the axial direction are overlapped at their open ends and connected by bolts, and includes a drive shaft 1 connected to an engine.
2 and a driven shaft 13 connected to the wheels are rotatably supported.

A drive shaft 12 is provided inside the clutch case 11.
Inner ring 20 supported by a spline connection to the shaft end of the outer ring 3
0 is coaxially arranged and supported inside and outside. Reference numeral 14 denotes a flat bearing that supports the drive shaft 12, and reference numeral 15 denotes a ball bearing that supports the driven shaft 13. Between the inner ring 20 and the outer ring 30, a pressure plate 21 movably locked to the inner ring 20 only in the axial direction, a pressing plate 31 supported by the outer ring 30, and a slit movably in the axial direction are supported. It is frictionally engaged with the friction plate 34 and the pressure receiving plate 32 so as to be separable. Reference numeral 16 denotes a needle-shaped thrust bearing interposed between the inner ring 20 and the pressing plate 31.

The pressure receiving plate 32 is supported by the driven shaft 13, and is prevented from moving in the axial direction by the thrust bearing 16 on the front surface and the step 13a on the rear surface, and a disc spring is provided between the rear surface and the end surface of the outer ring 30. The engagement spring 17 is compressed in a compressed state, and presses the outer ring 30 rightward in the figure. The pressing plate 31 is supported movably in the axial direction only on the inner surface of the open end of the outer ring 30 and is prevented from falling off by the inner diameter circlip 33. Thus, the pressing plate 31 is biased in the direction of the pressure receiving plate 32 by the elastic force of the engagement spring 17, and presses the pressure plate 21 and the friction plate 34 between the pressing plate 31 and the pressure receiving plate 32.

Reference numeral 40 denotes a clutch cam which is an operating element of the clutch. As shown in FIG. 2, the clutch cam 40 is formed by cutting a cam shaft 41 rotatably supported by the clutch case 11, a cam lever 42 connected to the outer end thereof, and a middle portion of the cam shaft 41 into a semicircle. And a cam-shaped cam portion 43 formed in a chipped manner. The cam lever 42 is connected to a clutch operator (not shown) such as a clutch pedal or a clutch lever. When the cam lever 42 is rotated, the cam portion 43 of the clutch cam 40 presses the end of the outer ring 30, Move to the left inside. As a result, the pressing plate 31 retreats to the left in the drawing, and the pressure plate 21 slips, so that power is not transmitted. Note that the above configuration is not much different from the configuration of a conventionally commercially available multi-plate clutch.

Here, in the present invention, the cam portion 43 and
A stop plate 50 is arranged between the outer ring 30 and the end. The stop plate 50 is fitted on the driven shaft 13 and is locked to the clutch case 11 only in the rotational direction, and is allowed to move slightly in the axial direction but is supported so as not to rotate. Reference numeral 55 denotes a braking friction plate, which is fixedly attached to the end surface of the outer race 30 as necessary. Reference numeral 55a denotes a hard anti-friction material made of a sintered alloy, which is baked on one side of the braking friction plate 55. Thus, when the clutch cam 40 is released, the stop plate 50 moves in the axial direction, and the outer ring 30 is moved.
Abut on the end. When the clutch cam 40 is further operated to the release side, the outer ring 30 is moved leftward by pressing the outer ring 30 against the engaging spring 17 via the stop plate 50. As a result, the friction clutch 10 is released, the connection between the drive shaft 12 and the driven shaft 13 is disconnected, and the transmission of power is cut off.

The stop plate 50 frictionally engages with the outer ring 30 which is rotating with the operation of the clutch cam 40, and stops the rotation. For this reason, the outer ring 30 includes the pressure plate 21 and the pressing plate 3
1 or at the same time that the engagement with the pressure receiving plate 32 is interrupted, the rotation of the outer ring 30 is rapidly stopped, and the occurrence of so-called creep is prevented. The provision of the braking friction plate 55 between the stop plate 50 and the outer ring 30 is not an essential requirement, but this increases the friction between the stop plate 50 and the outer ring 30 and reduces the effect of preventing the creep. Will be noticeable. However, since the braking plate 50 applies a large braking load for a short period of time until the start of operation of the clutch cam 40 and the actual transmission of power is cut off, the friction plate is made of an oil-impregnated bearing in order to reduce wear. It is preferable to stick a known sintered alloy as a material.

[0012]

According to the first aspect of the invention, since the driven side is stopped by the stopping plate at the same time as the friction clutch is disengaged, the problem that the driven side is continuously driven to rotate by creep is eliminated. In addition, the effect of creep elimination can be obtained by a simple structural change in which the stopping plate is interposed between the existing clutch cam and the outer ring. According to the second aspect of the present invention, the frictional material increases the frictional force between the outer ring and the stop plate, and a large braking force can be obtained even if the frictional area is small. According to the third aspect of the present invention, the friction material is a hard sintered alloy, so that a large friction force can be obtained, and the friction material is placed in a severe friction environment from the time when the clutch is released until the power is shut off. The durability of the material does not deteriorate. And so on.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a multiple disc clutch according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II.

[Explanation of symbols]

10 Multi-plate wet friction clutch 11
Clutch case 12 Drive shaft 13
Driven shaft 13a ··· Step 14 ··· Flat bearing 15 ···
Ball bearing 16 ··· Thrust bearing 17 ···
Engagement spring 20 ... Inner ring 21 ...
Pressure plate 30 ··· Outer ring 31 ···
Pressing plate 32 ... Pressure receiving plate 33 ...
Inner diameter circlip 34 ··· Friction plate 40 ··· Clutch cam 41 ···
Cam shaft 42 ... Cam lever 43 ...
Cam part 50: Stop plate 55:
Friction plate

Claims (3)

[Claims] An inner ring connected to a drive shaft and an outer ring connected to a driven shaft are housed in a clutch case, and a pressure plate supported by the inner ring is disposed between a pressure receiving plate supported by the outer ring and a pressing plate; A clutch cam that urges the pressing plate toward the pressure receiving plate by an engagement spring disposed between the outer ring and the outer ring, and that presses the outer ring against the engagement spring at the end of the outer ring to retract the pressing plate. A device for preventing creep of a multi-plate clutch, comprising a stopping plate interposed between the clutch cam and the end of the outer race, the stopping plate being locked only in the rotation direction in the clutch case. 2. The anti-creep device for a multi-plate clutch according to claim 1, wherein a friction material is attached to one of the outer race and the stop plate. 3. The anti-creep device for a multi-plate clutch according to claim 1, wherein a friction material made of a hard sintered alloy is attached to one of the outer ring and the stop plate.