JPH0225934Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a multi-disc torque transmission device suitable for a multi-disc clutch or brake used mainly in a power transmission section of a vehicle.

(Prior Art) A plate group includes a plurality of annular drive plates and annular driven plates arranged concentrically in an alternating manner, and an annular end plate and an annular piston are arranged at positions sandwiching the plate group, Multi-plate torque transmission devices for clutches or brakes are generally known in which an annular disc spring is disposed as a damper member on either the piston side or the end plate side. In such a device, in order to operate smoothly, in the relationship between the piston stroke and the transmitted torque when transitioning to the actuation side or the cutting side, a small torque is transmitted at the beginning of connection, and a large connection torque is transmitted as time passes. Generally, characteristics are required, and therefore, multi-stage characteristics are sometimes required for a disc spring used as a damper member.

In order to meet this demand, a configuration has conventionally been adopted in which two types of disc springs with different compression characteristics are stacked one on top of the other. In addition, as another configuration, a configuration is adopted in which multi-stage compression characteristics are obtained by changing the shape of the disc spring, such as by providing a radial notch in the inner circumference of the disc spring.

(Problems to be Solved by the Invention) The above configuration in which two types of disc springs having different compression characteristics are used in a stacked manner has the disadvantage of increasing costs because it is necessary to use a plurality of disc springs.
Also, since it is necessary to secure space for arranging multiple disc springs, the housing becomes larger and
This has the problem that a sufficient operating stroke cannot be secured. Moreover, when used in a vehicle, for example, it is necessary to set the operating characteristics of the disc spring based on the inertia of the vehicle, etc., but it is necessary to prepare a large number of disc springs in advance for this adjustment. Therefore, the work is troublesome.

In addition, in the above configuration in which multistage compression characteristics are obtained by changing the shape of the disc spring, processing is difficult because the disc spring is made of spring material, and it is difficult to change the compression characteristics, making it difficult to achieve the desired operation. Characteristics are difficult to obtain.
Furthermore, since a special shape disc spring is used, there is a problem in that the cost is high.

(Means for Solving the Problems) In order to solve the above problems, the multi-plate torque transmission device for a clutch or brake of the present invention is a plate formed by a plurality of annular drive plates and annular driven plates arranged concentrically alternately. a stopper for restricting movement of the end plate when the piston presses the plate group against the end plate; In a multi-plate torque transmission device for a clutch or brake in which an annular disc spring is arranged as a damper member between the end plate and the disc spring, the disc spring expands at a uniform taper angle from the inner circumference to the outer circumference. The inner circumferential edge is in contact with the end plate, and the end plate is provided with a step or an inclined surface on the disc spring contact surface, so that the compression fulcrum of the disc spring in contact is on the side where the rigidity is increased. It is designed to change during compression.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a sectional view of a multi-plate torque transmission device according to an embodiment of the present invention, in which a large-diameter clutch cover 12 is integrally formed at the end of an output shaft 11 located at the center. clutch cover 1
An annular clutch room 12a opening to the left in the drawing is concentrically formed within the clutch chamber 2. A gear 14 is disposed on the left side of the clutch cover 12 in the figure, and is rotatably supported concentrically on the shaft 11 via a ball bearing 13.A power source (not shown) is connected to teeth formed on the outer circumference of the gear 14. By connecting these, power is input to the gear 14. Gear 14 has clutch room 12a
A cylindrical boss portion 15 that protrudes inward is integrally formed.

A large number of grooves 16 parallel to the shaft 11 are formed at equal intervals in the circumferential direction on the inner surface of the outer periphery of the clutch cover 12. Protrusions formed on the outer periphery of one end plate 18 disposed close to each other are slidably engaged with the groove 16. Four annular drive plates 20 having friction facings fixed to their sides are arranged between each driven plate 17 and between each driven plate 17 and the end plate 18. A large number of protrusions projecting radially inward are formed on the inner circumferential portion of the drive plate 20, and the protrusions can only slide freely into grooves 19 parallel to the shaft 11 formed on the outer circumferential surface of the boss portion 15. engaged.

An annular piston 21 is fitted to the bottom side of the clutch room 12a so as to be slidable only in the parallel direction to the shaft 11, with both inner and outer peripheral ends kept liquid-tight by O-rings. . Piston 21
An annular protrusion is formed on the driven plate 17 side of the outer periphery so that it can be brought into pressure contact with the driven plate 17. A small gap is provided between the piston 21 on the opposite side of the protrusion and the bottom surface of the clutch room 12a, forming a hydraulic chamber 22. The inner peripheral end of the hydraulic chamber 22 is connected to the shaft 1.
It communicates with one end of an oil passage 23 formed in 1,
The other end of the oil passage 23 is connected to a hydraulic control mechanism (not shown). One end of a coil spring 24 for returning the piston 21, which is concentric with the shaft 11, is in contact with the surface of the inner peripheral part of the piston 21 on the gear 14 side. With the other end of the coil spring 24 in contact with the spring seat 26, the coil spring 24 constantly pushes the piston 21 to the right in the figure.

On the other hand, an annular disc spring 27 is disposed in the clutch room 12a closer to the gear 14 than the end plate 18.
are arranged, and in the illustrated state, the disc spring 27 is in a free state. Since the outer circumferential portion of the disc spring 27 is supported by the inner surface on the outer circumferential side of the clutch cover 12, the disc spring 27 is held concentrically with the shaft 11, and is fixed to the inner peripheral portion of the groove 16 near the gear 14. Movement of the disc spring 27 toward the gear 14 is restricted by a snap spring 28 as a stopper. The disc spring 27 has a shape that becomes closer to the end plate 18 as it goes toward the inner circumference, and the disc spring 27
The inner circumferential edge of 7 is in contact with the inner circumferential edge of the end plate 18 . The end face of the end plate 18 on the side of the disc spring 27 is a plane extending in the radial direction of the shaft 11, and a stepped portion 29 is formed at the radially intermediate part of the end face so that the outer peripheral part projects toward the disc spring 27 side. has been done. Note that the stepped portion 29 is annular and concentric with the shaft 11, and is easily formed in advance by machining. It is easy to change the position and step difference of the step portion 29 by ordinary simple machining, and therefore it is easy to obtain a desired shape or change the shape.

Next, the operation will be explained. The state shown in Figure 1 is hydraulic chamber 2.
2 shows a state in which hydraulic pressure is not supplied,
Therefore, the piston 21 does not press the driven plate 17. That is, the torque input to the gear 14 is transmitted from the gear 14 to the drive plate 20 via the boss portion 15;
Since the space between the shaft 11 and the driven plate 17 is in a disconnected state, input torque is not transmitted to the shaft 11.

When hydraulic pressure is supplied from the oil passage 23 to the hydraulic chamber 22, the piston 2 resists the coil spring 24.
1 slides toward the gear 14 side, and the driven plate 17
Press. This allows each driven plate 1
7. The distance between the end plates 18 becomes narrower, and the drive plate 20 is sandwiched and pressed into contact with each other.
At the same time, the disc spring 27 begins to be compressed by the end plate 18. In the initial state of compression, the disc spring 27
Since the inner circumferential end of the disc spring 27 is in contact with the end plate 18, the rigidity of the disc spring 27 is weak, and the load on the compression stroke of the disc spring 27 does not increase significantly.
The compression stroke S to spring load P characteristics in this case are, for example, the relationship from 0 to s1 in FIG. 2.

Furthermore, when strong pressure is supplied to the hydraulic chamber 22, the disc spring 27 is further compressed by the end plate 18, and eventually the radial middle part of the disc spring 27 becomes the stepped part 2.
It comes into contact with the corner of 9. This point is point s1 in FIG. If the hydraulic pressure to the hydraulic chamber 22 is further increased, the corner of the stepped portion 29 becomes the fulcrum of the disc spring 27, so the load characteristic of the disc spring 27 changes from s1 to s in FIG.
As shown in 2, the slope becomes steep, and the transmitted torque suddenly increases.

The disc spring 27 is compressed until it becomes flat (second
s2 in the figure, when the end plate 18 comes into direct contact with the snap spring 28 via the disc spring 27, the driven plate 17 and the drive plate 20 are connected between the clutch cover 12 and the boss portion 15.
The torque from the gear 14 is integrally transmitted to the shaft 11.

Next, when the oil pressure in the hydraulic chamber 22 is lowered from the connected state, the operation is opposite to the above-mentioned operation. Driven plate 17, end plate 18, and piston 21 are moved toward the bottom side of clutch room 12a by the spring force of coil spring 24 and disc spring 27, disc spring 27 becomes free, and piston 21 moves toward driven plate 17. If you move away from
The state is again cut as shown in the figure.

(Another embodiment) The stepped portions 29 are provided concentrically in two or more locations in stages,
It is also possible to change the compression characteristics in three or more stages.

Further, instead of the step portion 29, a tapered surface 30 (slanted surface) as shown in FIG. 3 may be formed on the end plate 18. The inclination angle θ1 of the tapered surface 30 is set to be larger than the inclination angle θ2 of the disc spring 27 in the free state. Therefore, in this embodiment, the inner circumferential end of the disc spring 27 touches the tapered surface 30 at the initial stage of compression of the disc spring 27.
Point s1 in FIG. 2 is when the radially intermediate portion of the disc spring 27 comes into contact with the outer peripheral end of the tapered surface 30.

Further, instead of the stepped portion 29 and the tapered surface 30, a tapered surface 31 (slanted surface) formed in a curved shape slightly convex toward the inner circumference as shown in FIG. 4 may be employed. The tangential direction of the inner peripheral end of the tapered surface 31 is slightly larger than the inclination angle of the disc spring 27, and the tangential angle is set to gradually increase toward the outer peripheral side. Therefore, in this embodiment, the inner peripheral end of the disc spring 27 touches the tapered surface 31 at the initial stage of compression of the disc spring 27.
As the degree of compression of the disc spring 27 increases, the position of the disc spring 27 in pressure contact with the tapered surface 31 changes toward the outer peripheral side. Therefore, in this embodiment, as shown in FIG.
The spring load P characteristics form a curved relationship. Also, s
Characteristic changes at one point become smooth. Note that various compression stroke S to spring load P characteristic curves can be obtained by variously changing the shape of the tapered surface 31.

Alternatively, the shaft 11 may be used as the input side, and the gear 14 may be used as the output side. Also gear 14 or shaft 11
By employing a fixing member in place of either one, it can also be used for brakes.

(Effect of the invention) As explained above, according to the invention, the disc spring 2
7 is placed between the stopper (snap spring 28) and the end plate 18, and the end plate 18 is
A stepped portion 29 or an inclined surface (tapered surfaces 30, 31) is provided on the contact surface of the disc spring 27, so that the disc spring 27 comes into contact with the disc spring 27.
The compression fulcrum changes during compression to the side that increases the rigidity, so the end plate 18 is much easier to attach and detach than the piston 21, so replacing the end plate 18 can be done easily and quickly. The desired cushioning effect can be selected by changing the multi-stage characteristics.

Also, stop the disc spring 27 (snap spring 2
8) and the end plate 18, the piston 21 and the plate group (plates 17,
20), the plate group (plate 1
There is no need to provide a thick press plate for uniformly transmitting force to the entire end face of the plate group (plates 17, 20) and protecting the plate group (plates 17, 20), thereby achieving cost reduction and space saving.

Further, the disc spring 27 has a normal shape that expands at a uniform taper angle from the inner periphery to the outer periphery, and the end plate 18 has a stepped portion 29 or an inclined surface (tapered surfaces 30, 31) on the contact surface of the disc spring 27. ) By providing
Since the compression fulcrum of the abutting disc spring 27 changes during compression to the side that increases rigidity, processing of the end plate 18 is much easier than processing the disc spring 27 made of a spring material. Therefore, desired multi-stage characteristics can be easily and accurately obtained, and processing costs can be significantly reduced.

Furthermore, since the disc spring 27 is not also used as a return spring (coil spring 24) for the piston 21, it is easy to design to obtain desired multi-stage characteristics, and a good cushioning effect can be easily and reliably obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a multi-plate torque transmission device according to an embodiment of the present invention, Figs. 2 and 5 are graphs showing the compression stroke to spring load characteristics, respectively, and Figs. 3 and 4 are graphs showing different FIG. 2 is a cross-sectional view of main parts showing an example. 17, 20...Plate (plate group), 18
... End plate, 27 ... Belleville spring, 28 ...
Snap spring (stopper), 29...stepped part, 3
0, 31...Tapered surface (slanted surface).

Claims (1)

[Scope of utility model registration request] It has a plate group consisting of a plurality of annular drive plates and annular driven plates arranged concentrically alternately, an annular end plate and an annular piston are arranged at positions sandwiching the plate group, and the piston is arranged to sandwich the plate group. In a multi-plate torque transmission device for a clutch or brake, in which an annular disc spring is disposed as a damper member between a stopper that restricts movement of the end plate when the group is pressed against the end plate. , the disc spring expands at a uniform taper angle from the inner periphery to the outer periphery, and the inner peripheral edge is in contact with the end plate, and the end plate has a step or a step on the disc spring contact surface. A multi-disc torque transmission device for a clutch or brake, characterized in that an inclined surface is provided so that the compression fulcrum of the abutting disc spring changes to the side that increases rigidity during compression.