JPS601428A - Multiple disc clutch or brake - Google Patents

Abstract

PURPOSE:To make it possible to correct a transmission torque capacity according to torque, by connecting an intermediate member for connecting a cylinder member with a friction plate so as to permit transmission of a rotational force with the cylinder member through a helical spline or cam. CONSTITUTION:A piston 14 installed in a cylinder portion 12a of a clutch drum 12 is integrally formed with an annular member 16. The clutch drum 12 is provided with an internal helical spline 12b at an inside diameter portion thereof, and the internal helical spline 12b is meshed with an external helical spline 16a provided on an outer circumference of the annular member 16 integral with the piston 14. Further, an internal helical spline 16b provided on an inside diameter portion of the annular member 16 is meshed with external splines of driven plates 28. A friction plate 27 is formed by the driven plates 28 and drive plates 30.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a multi-disc clutch or brake used in automatic transmissions for vehicles and the like.

(b) Prior art multi-disc clutches use hydraulic force acting on a piston to press a plurality of friction plates to transmit or disconnect rotational force between rotating members, but their transmission torque capacity is It is determined by the number of friction plates, the friction coefficient of the friction plates, and the force exerted by the piston. In the case of a multi-disc clutch used in a vehicle automatic transmission, in order to perform a smooth shift, it is necessary to adjust the transmission torque capacity of the multi-disc clutch in accordance with the torque input to the multi-disc clutch. In conventional multi-disc clutches, the transmission torque capacity is adjusted by quietly controlling the hydraulic pressure applied to the piston. However, it is relatively difficult to always control the transmission torque capacity of the multi-disc clutch approximately equal to the input torque using hydraulic pressure. The line pressure, which is the operating pressure supplied to the multi-disc clutch, is generally controlled to a value depending on the negative pressure in the engine intake pipe or the throttle opening, but even when the engine is idling (throttle fully closed), the minimum oil pressure is Because of this, the line pressure during idling is higher than it should be. Therefore, what is the ratio of the minimum throttle total pressure to the engine when the throttle is fully open and when the throttle is fully closed? It is smaller than the torque ratio.

Therefore, for example, in the case of a multi-disc clutch that requires a large transmission torque capacity when driven from the engine side, and conversely requires a very small transmission torque capacity when driven from the driving wheel side (in the case of engine braking). If the transmission torque capacity of the multi-disc clutch is set in accordance with the required transmission torque capacity when the vehicle is driven from the engine side, the transmission torque capacity of the multi-disc clutch will become excessive during engine braking. In such a case, when the multi-disc clutch is switched to change gears, problems such as a large shift shift or engine racing may occur. The cause of the above problems is that the line pressure is set uniformly and multiple friction elements (clutches, brakes, etc.)
The problem lies in the fact that operating pressures with the required characteristics are not supplied to each of them. However, it is practically difficult to adjust the operating pressure of each friction element according to its needs.

Furthermore, the line pressure is set in accordance with the assumption of the torque input to the friction element in advance, and therefore does not necessarily always correspond to the torque that is actually input. Also from this point of view, there is a possibility that the transmission torque capacity of the multi-disc clutch may be too large or too small.

(c) Purpose of the Invention The present invention provides, in addition to adjusting the transmission torque capacity by hydraulic pressure,
The object of the present invention is to obtain a multi-disc clutch or brake capable of modifying the transmission torque capacity according to the torque actually transmitted.

(D) Structure of the Invention The present invention solves the above problems by providing an intermediate member connected to the cylinder member by a helical spline or a cam. That is, in the multi-disc clutch or brake according to the present invention, an intermediate member is provided between the cylinder member and the friction plate to connect them to each other so as to be able to transmit rotational force, and the cylinder member and the intermediate member are connected to a helical spline or a cam. The intermediate member is capable of transmitting an axial force generated by a helical spline or a cam to the piston.

(e) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 4 of the accompanying drawings.

(First Embodiment) FIG. 1 shows a multi-disc clutch 10 according to the present invention. A piston 14 is inserted into a cylinder portion 12a of the clutch drum 12. An annular member 16, which will be described later, is integrally formed with the piston 14. The outer circumference and inner circumference of the piston 14 are sealed by seal members 18 and 20, respectively. Hydraulic pressure can be supplied from a passage hole 24 to an oil chamber 22 defined by the cylinder portion 12a and the piston 14.

The piston 14 is subjected to a force in the left direction in FIG. 1 by the bellows spring 26. Therefore, when oil pressure is not supplied to the oil chamber 22, the piston 14 is pushed back to the left as shown in the figure. An inner diameter helical spline 12b is provided on the inner diameter portion of the clutch drum 12, and an outer diameter helical spline 16a provided on the outer periphery of an annular member 16 integral with the piston 14 meshes with this inner diameter helical spline 12b. . The vertical splines 12b and 16a have helix angles with directions and magnitudes as described below. An inner diameter spline 16b is provided on the inner diameter portion of the annular member 16. The outer diameter spline of the driven plate 28 is engaged with the inner diameter spline 16b. In this embodiment, three driven plates 28 are provided, and they are arranged alternately with three drive plates 30. This driven plate 2
8 and drive plate 30 by friction plate 27
is configured. A dish plate 32 is located between the leftmost driven plate 28 and the piston 14 in FIG.
is provided.

Further, a pressure plate 34 is arranged on the right side of the rightmost drive plate 30 in FIG.

Pressure plate 34 also has an outer diameter spline that engages inner diameter spline 16b of annular member 16. The pressure plate 34 is restrained from moving in the axial direction with respect to the clutch drum 12 by a snap ring 36. Note that the clutch drum 12 is a separate rotating member 3.
It has a spline 12c that meshes with 8. The drive plate 30 also has an internal spline that engages with another rotating member 40.

Next, the operation of this embodiment will be explained.

When oil pressure is not acting on the oil chamber 22, the multi-disc clutch 10 is in a released state, and the clutch drum 12, the rotating member 38, and the rotating member 40 stop or rotate independently of each other. From this state, when operating pressure is supplied to the oil chamber 22 through the oil passage 24, the piston 14 moves to the right in FIG. 1 against the force of the plate spring 26. Therefore, there is no pressure between the drive plate 30 and the driven plate 28.
- Attachment begins to come into play. As a result, for example, the rotating member 40
The rotational force is transmitted from the drive plate 30 to the driven plate 28 by the frictional force between the two, and this rotational force is further transmitted to the annular member 16 that meshes with the driven plate 28.
transmitted to. Since the annular member 16 is engaged with the inner diameter helical spline 12b of the clutch drum 12 by the outer diameter helical spline 16a, the rotational force of the annular member 16 is divided into the rotational force and thrust force of the clutch drum 12 depending on the helical spline's twist angle. be divided.

The rotational force of the clutch drum 12 is transmitted to the rotating member 38 connected thereto, and when the multi-plate clutch 10 is fully engaged, the rotating member 40 and the clutch drum 12
, and the rotating member 38 rotate together. The thrust force generated by the meshing of the helical splines 16a and 12b is a force that depends on the magnitude and direction of the helical spline's twist angle. That is, the larger the torsion angle, the greater the thrust force, and the direction of action of the thrust force is opposite depending on the direction of rotational force. For example, if the twist angle of the helical spline is set so that a thrust force in the left direction in FIG. 1 acts on the annular member 16 when the rotational force from the rotational member 38 is transmitted to the rotational member 40, the thrust force It acts in the direction of reducing the pressing force by the piston 14. Therefore, since the pressing force acting on the drive plate 30 and the driven plate 28 is reduced, the transmission torque capacity of the multi-disc clutch 10 is reduced accordingly.

Conversely, when rotational force is transmitted from the rotating member 40 to the rotating member 38, a thrust force in the right direction in FIG. 1 acts, and this thrust force is added to the pressing force of the piston 14. be done. Therefore, the pressing force between the drive plate 30 and the driven plate 28 increases, and the multi-plate clutch 10
The transmission torque capacity of is increased. Therefore, even if it is possible to increase the transmission torque capacity of the multi-disc clutch 10 when driven from the LF engine side, and to reduce the transmission torque capacity when driven from the drive wheel side, it is possible to Even in cases where it is not possible to obtain an appropriate ratio of the transmission torque capacity using hydraulic pressure alone, it is possible to obtain the optimum ratio of transmission torque capacity in both directions of movement. become able to. Since the torsion angle of the helical spline can be arbitrarily set within a range that is not extremely large, it should be set so that an optimal transmission torque capacity ratio can be obtained depending on the rotational force acting on the multi-disc clutch 10. I can do it.

Furthermore, by reversing the direction of the helical spline's helix angle, it is possible to reduce the transmission torque capacity when driven from the engine side and increase the transmission torque capacity when driven from the drive wheel side.

(Second Embodiment) In the first embodiment, the piston 14 and the annular member 16 are integrally formed, but as in the second embodiment shown in FIG.
There is no problem even if both are divided into separate members.

(Third example) In 3rd and 4th, a third embodiment of the present invention is shown.

In the first and second embodiments, the clutch drum 12 and the annular member 16 were connected by a helical spline, but in the third embodiment, they are connected via a cam. That is, the slider 50 is guided in the cam groove 16a' of the annular member 16', and the slider 50 is restrained by the clutch drum 12'. One wall of the cam groove 16a' is inclined with respect to the axial direction. It is clear that even with such a configuration, sliding and straining forces are generated in accordance with the transmitted torque, and the transmitted torque capacity is thereby adjusted.

In this case, the direction of the thrust force can be determined depending on which side of the wall of the cam groove 16a' is inclined, and the thrust force can be generated only in one direction.

Note that all of the above embodiments have been described with respect to multi-disc clutches, but considering that the latch drum is fixed, a clutch and a brake are equivalent, so the present invention can be applied to a multi-disc brake. It is clear that this can be done.

(v) As described in detail, the multi-disc clutch or brake according to the present invention includes a cylinder member (12) and a friction plate (2).
7) and an intermediate member (in the embodiment shown in FIGS. 1 and 2, an annular member 1
6'', and in the embodiment shown in FIGS. 3 and 4, the annular member 16
' and a slider 50''), the cylinder member and the intermediate member are connected by a helical spline or a cam, and the intermediate member is capable of transmitting the axial force generated by the helical spline or cam to the piston (14). It is possible to add or subtract a thrust force depending on the direction of action of the rotational force to the force of the piston, increasing the degree of freedom in setting the transmission torque capacity of the multi-disc clutch or brake.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a multi-disc clutch that is a first embodiment of the present invention, FIG. 2 is a diagram showing a multi-disc clutch that is a second embodiment of the present invention, and FIG. 3 is a diagram showing a multi-disc clutch that is a second embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3, showing an example of a multi-disc clutch. 12φ clutch drum, 12aφφ cylinder part,
12b...Inner diameter helical spline, 14. ψ piston, 16-.Fist annular member, 16a..φ outer diameter helical spline, 18.20-.Seal member, 22..-
Oil chamber, 24, passage hole, 26, φ, side spring, 27,
φ・Friction plate, 28--- Driven plate, 3
0- @- Drive plate, 32/φ dish plate, 34... Pressure plate, 38, 40
・One rotation member. Figure 1 0 Figure 2 6

Claims (1)

[Claims] An intermediate member is provided between the cylinder member and the friction plate to connect the two to each other so as to be able to transmit rotational force, the cylinder member and the intermediate member are connected by a helical spline or a cam, and the intermediate member is connected by a helical spline or a cam. Multi-disc clutch or brake capable of transmitting the resulting axial force to the piston.