JP2002122211A - Lock-up device of torque converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable for enlargement of a torsion spring in the lock-up device of a torque converter. SOLUTION: This lock-up device 6 of the torque converter is provided with a piston 8 and a damper mechanism 13. The damper mechanism 13, which connects the piston 8 to a turbine elastically in the rotating direction, is provided with a drive plate 9 fixed to a surface of the circumferential portion of the piston 8 in the turbine side, a driven plate 10 relatively non-rotatably engaged with the turbine, and a torsion spring 12 connecting the both to each other in the rotating direction. In the drive plate 9, a cutout 37 is formed in a position corresponding to the spring 12 in the drive plate 9 and the side of a front cover 3 of the spring 12 is supported to the piston 8 in the cutout 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a torque converter, and mechanically transmits torque from an input-side rotating body to an output-side rotating body, and twists from an input-side rotating body to an output-side rotating body. The present invention relates to a torque converter lock-up device for absorbing and attenuating vibration.

[0002]

2. Description of the Related Art In general, a damper mechanism attenuates torsional vibration transmitted from an input side rotating body to an output side rotating body while transmitting torque from an input side rotating body to an output side rotating body. As an example of such a damper mechanism, there is a lock-up device arranged inside the torque converter.

[0003] A torque converter is a device that has three types of impellers (impeller, turbine, and stator) inside and transmits torque through internal working oil. The impeller is fixed to a front cover as an input-side rotating body. When the front cover rotates, hydraulic oil flows from the impeller toward the turbine, and torque is transmitted from the turbine to the output side rotating body. The lockup device is arranged in a space between the turbine and the front cover, and is a device for directly transmitting torque from the front cover to the turbine by mechanically connecting the front cover and the turbine.

Normally, a lock-up device includes a disc-shaped piston connectable to a front cover, a drive plate (retaining plate) fixed to an outer peripheral portion of the piston, and an elastic member (for example, torsion) held thereby. And a driven plate that supports both ends of the torsion spring in the rotation direction. The driven plate is fixed to a turbine shell or a turbine hub of the turbine.

When the lock-up device is operated, torque is transmitted from the front cover to the piston and transmitted to the turbine via the torsion spring. Further, when the lock-up device receives the torque fluctuation from the engine, the torsion spring is compressed between the drive plate and the driven plate in the damper mechanism including the torsion spring, and absorbs and attenuates torsional vibration.

[0006]

On the other hand, there is a demand for higher performance of the damper mechanism by using the vehicle at a low speed and increasing the torque. In recent years, a torque converter that transmits torque by fluid only at the time of starting and activates a lockup device at a speed of, for example, 20 km / h or more is known. In such a structure in which the lock-up region is increased, it is required to improve the performance of the torsion spring so that torsional vibration can be sufficiently absorbed and attenuated in response to torque fluctuations from the engine. Specifically, it is required that the diameter of the torsion spring of the damper mechanism be increased to improve the vibration absorption / damping characteristics against torsional vibration.

However, the lock-up device needs to be arranged in a limited space in the torque converter. In the conventional lock-up device, the piston and the drive plate are arranged on one axial side of the torsion spring. Therefore, the torsion spring cannot be made sufficiently large.

An object of the present invention is to make it possible to increase the size of an elastic member such as a torsion spring in a lockup device for a torque converter.

[0009]

According to a first aspect of the present invention, there is provided a lock-up device for a torque converter, comprising: a front cover having a friction surface on an inner side; an impeller forming a fluid chamber together with the front cover; And a turbine that is arranged in such a manner as to secure a space between the torque converter and the front cover. The lockup device is a device that is disposed in a space and mechanically connects and disconnects the front cover and the turbine by a change in pressure in the space. The lockup device has a piston and a damper mechanism. The piston is movable in the space by a change in pressure of the space, and is arranged close to a friction surface of the front cover. The damper mechanism is a mechanism for elastically connecting the piston and the turbine in the rotation direction, and includes a drive plate fixed to a turbine-side surface of an outer peripheral portion of the piston, and a driven A plate, and an elastic member that connects the drive plate and the driven plate in the rotation direction. A cutout is formed at a position corresponding to the elastic member in the drive plate, and a front cover side portion of the elastic member is disposed in the cutout.

In this lockup device for a torque converter, when the piston is connected to the front cover friction surface, torque from the front cover is transmitted to the damper mechanism via the piston. In the damper mechanism, torque is transmitted in the order of the drive plate, the torsion spring, and the driven plate, and torque is output from the driven plate to the turbine. When torsional vibration is input from the front cover to the lock-up device, the torsion spring is compressed in the rotational direction between the drive plate and the driven plate.

As described above, since the notch is formed in the drive plate in the lock-up device, the diameter of the torsion spring can be increased by the thickness of the drive plate as compared with the related art.

According to a second aspect of the present invention, in the lock-up device for a torque converter, the outer peripheral edge of the notch sounds in an arc shape, and the corner on the elastic member side is chamfered. Therefore, wear due to contact between the torsion spring and the outer peripheral edge of the notch is reduced.

According to a third aspect of the present invention, the turbine-side surface of the outer peripheral portion of the piston is subjected to a wear-resistant treatment. Therefore, wear of the piston due to sliding of the torsion spring hardly occurs.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Configuration Torque Converter FIG. 1 shows a torque converter 1 according to an embodiment of the present invention.
FIG. In FIG. 1, the entire structure of the torque converter 1 including the front cover 3, the impeller 4, and the turbine 5 is the same as that of the conventional one, so that the description will be simplified. An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of FIG. In addition, OO shown in FIG. 1 is a rotation axis of the torque converter 1, an arrow R1 shown in FIG. 2 is a rotation direction of the engine, and an arrow R2 is a rotation direction on the opposite side.

The front cover 3 is a circular slope member connected to the crankshaft of the engine. The front cover 3 and the impeller 4 constitute a hydraulic oil chamber of the torque converter 1. The turbine 5 is disposed in the hydraulic oil chamber and disposed to face the impeller 4 in the axial direction. The inner peripheral portion of the turbine 5 is connected to a turbine hub 11 described later. The turbine hub 11 is connected to a main drive shaft (not shown) of the transmission.

The turbine hub 11 is a cylindrical member.
The turbine hub 11 is composed of a boss 60 and a circular flange 61 formed on the outer peripheral surface thereof. Boss 60
A spline 62 is formed on the inner peripheral surface of the. The spline 62 is in spline engagement with the main drive shaft on the transmission side. Further, an outer peripheral surface 63 is formed on the boss 60. Outer peripheral surface 63 is flange 6
1 with respect to the engine side.

Lock-up device 6 will be described with reference to [0017] lockup device Figure 2-5. FIG. 2 is a partial plan view of a piston mechanism in which a drive plate 9 is mounted on a piston 8, and FIG. 3 is a partial plan view in a case where a driven plate 10 is further arranged in the structure of FIG. FIG. 4 is a vertical sectional view taken along the line IV-IV of FIG.
FIG. 5 is a vertical sectional view taken along line VV of FIG.

The lock-up device 6 is a device for absorbing and attenuating the input torsional vibration while mechanically transmitting the torque from the front cover 3 to the turbine 5. That is, the lockup device 6 has a clutch function and a damper function. The lockup device 6 is arranged in the space between the front cover 3 and the turbine 5 as is apparent from FIG. The lock-up device 6 mainly includes a piston 8, a drive plate 9, a driven plate 10, and a plurality of torsion springs 12. These members as a whole are the damper mechanism 13
Is composed. In the damper mechanism 13, the piston 8 and the drive plate 9 function as input members,
The driven plate 10 functions as an output-side member, and the torsion spring 12 functions as an elastic member between the two members.

The input member comprises a piston 8 and a drive plate 9. The piston is an annular and disk-shaped member arranged so as to divide the space between the front cover 3 and the turbine 5 in the axial direction, and is movable in the axial direction by a change in oil pressure in the torque converter 1. It is a member. The piston 8 is arranged in the vicinity of the transmission side of the front cover 3 in the axial direction. The piston 8 has an annular friction coupling portion 15 on the outer peripheral side. The friction coupling portion 15 has an annular and flat shape, and faces the annular and flat friction surface 3a of the front cover 3. Also,
An annular friction facing 16 is attached to the friction cover 15 on the front cover 3 side. A heat treatment such as gas nitrocarburizing is applied to the surface of the friction connection portion 15 on the turbine 5 side.
An outer peripheral side cylindrical portion 17 extending toward the transmission in the axial direction is formed on the outer peripheral side of the piston 8. An inner peripheral cylindrical portion 18 extending toward the transmission in the axial direction is formed on the inner peripheral edge of the piston 8. Inner circumference side tubular part 1
8 is supported in the radial direction by the outer peripheral surface 63 of the boss 60. This allows the piston 8 to move in the axial direction and the rotational direction with respect to the turbine hub 11.

The drive plate 9 is fixed to the piston 8, holds a torsion spring 12 described later, and functions as an input member for inputting torque to the torsion spring 12. The drive plate 9 is an annular plate member, and is arranged on the axial transmission side (turbine 5 side) of the outer peripheral portion of the piston 8. The drive plate 9 is entirely carbonitrided. The drive plate 9 includes an inner peripheral annular portion 25 and an outer peripheral spring support portion 26. Annular part 25
Is fixed to the outer peripheral portion of the piston 8 by a plurality of rivets 28 arranged in the circumferential direction. Spring support 26
Extends outward from the annular portion 25 and is disposed on the axial transmission side of the friction coupling portion 15 of the piston 8. That is, the spring support portion 26 is supported on the surface of the friction connection portion 15 of the piston 8 on the turbine 5 side, and further supported on the inner peripheral surface of the outer cylindrical portion 17. Describing in more detail, the spring support portion 26 mainly includes the annular portion 25.
Intermediate connecting portions 3 extending radially outward from the outer peripheral edge of
2 and an outer peripheral side tubular portion 33 extending from the outer peripheral edge toward the transmission in the axial direction.

A notch 37 penetrates in the axial direction between the intermediate connecting portions 32 in the rotation direction. The notch 37 is a hole portion having a certain width in the radial direction and extending in an arc shape long in the rotation direction. Since the portion corresponding to the notch 37 is a hole penetrating in the axial direction, the surface of the friction coupling portion 15 which is the outer peripheral portion of the piston 8 on the axial transmission side is exposed. The notch here refers to a hole formed by punching a part of a continuous plate member, and the periphery thereof forms a continuous edge. In addition, the notch may have a partially open shape if necessary. Since the notch 37 has a simple shape that has only been stamped out by press working, it is easy to manufacture.

The outer peripheral edge of the notch 37 has an arc shape in accordance with the operation of the torsion spring 12. Further, the corner of the outer peripheral edge of the notch 37 on the axial transmission side is chamfered to form a chamfered portion 37a facing the inner peripheral side and the axial transmission side. The chamfered portion 37 a is formed over the entire outer peripheral edge of the notch 37. As described above, when the torsion spring 12 operates, it moves radially outward and is compressed in the rotational direction.
Wear between the drive plate 9 and the outer peripheral edge of the cutout 37 is less likely to occur.

The distal end of the outer cylindrical portion 33 is a bent portion 35 which is bent obliquely toward the inner circumference. As shown in FIG. 4, a spring support portion 40 is formed at the bent portion 35 at equal intervals in the circumferential direction and further protruded toward the inner peripheral side by drawing. The spring support part 40 is formed corresponding to the intermediate connecting part 32.

Further, on the inner peripheral edge of the notch 37, an inner peripheral side support portion 41 protruding toward the transmission in the axial direction is formed. The inner peripheral side support portion 41 extends in an arc shape in the rotation direction corresponding to a middle portion of the notch 37 in the rotation direction.

The torsion spring 12 is arranged at a position corresponding to the notch 37 of the drive plate 9. The torsion spring 12 includes, for example, a coil spring, a spring seat, a small coil spring,
It is a member composed of an elastic member assembly in which a float body or the like is appropriately combined. The torsion spring 12 has a radially outer side supported by the outer cylindrical portion 33 and a radially inner side supported by the inner peripheral side supporting portion 41. Further, the torsion spring 12 is supported by the friction coupling portion 15 of the piston 8 on the engine side in the axial direction, and is supported by the bent portion 35 on the transmission side in the axial direction. Further, both ends of the torsion spring 12 in the rotation direction are
And at both ends of the intermediate connecting portion 32 in the rotation direction.
Here, as shown in FIG. 4, the intermediate connecting portion 32 is formed with a step by drawing so that the inner peripheral portion is raised in the axial direction as compared with the outer peripheral side, so that the contact area with the torsion spring 12 increases. I have. As described above, the torsion spring 12 is held by the drive plate 9. That is, the piston 8, the drive plate 9, and the torsion spring 12 form a piston mechanism as a sub-assembly.

The driven plate 10 is a member to which torque is output from the torsion spring 12. The driven plate 10 is an annular and disk-shaped member, and is disposed between the turbine 5 and the piston 8 in the axial direction. The inner peripheral portion of the driven plate 10 is fixed to the flange 61 by a plurality of rivets 47 arranged in a circumferential direction.
A plurality of spring support claws 5 are provided on the outer peripheral edge of the driven plate 10.
1 is formed. Each spring support claw 51 includes a protruding portion 51a protruding radially outward from the outer peripheral edge, and a claw portion 51b extending therefrom toward the engine side in the axial direction.
The claw portion 51b has main surfaces facing both sides in the radial direction, and side surfaces facing both sides in the rotation direction. The spring support claws 51 are formed corresponding to the intermediate connecting portions 32 of the drive plate 9, and the claw portions 51 b extend from the engine side in the axial direction so as to be located on the inner peripheral side of the spring support portions 40. The tip of the claw portion 51b is close to a portion of the intermediate connecting portion 32 that is in contact with the piston 8. Both sides of the claw portion 51b in the rotation direction are in contact with or close to both ends of the torsion spring 12 in the rotation direction.

Further, a plurality of cutout holes 52 are formed in a radial portion of the driven plate 10. (2) Operation Next, the operation will be described. When hydraulic oil is supplied to the inner peripheral portion of the front cover 3 and the piston 8 by a hydraulic operating mechanism (not shown), the hydraulic oil flows through the space between the front cover 3 and the piston 8 to the outer peripheral side. The hydraulic oil flows further between the front cover 3 and the friction facing 16 to the outer peripheral side, and flows into the torque converter body from between the outlet of the front cover 3 and the inlet of the turbine 5. In this state, the entire piston mechanism has moved toward the transmission in the axial direction, and the clutch connection at the friction connection portion 15 has been released.

Subsequently, when hydraulic oil is discharged from the space between the front cover 3 and the piston 8 by a hydraulic operating mechanism (not shown), the entire piston mechanism moves toward the engine in the axial direction. As a result, the friction facing 16 is strongly pressed against the front cover 3 and the clutch is engaged. The torque from the front cover 3 is transmitted to the damper mechanism 13 via the piston 8. In the damper mechanism 13, the drive plate 9 moves the torsion spring 12
Is transmitted to the driven plate 10 via the. The torque is output from the driven plate 10 via the turbine hub 11 to a shaft (not shown). When torque fluctuation is input from the engine side in the clutch engaged state, the torsion spring 12 is compressed in the rotation direction between the drive plate 9 and the driven plate 10 in the damper mechanism 13. Specifically, the torsion spring 1 is connected between the spring supporting portion 40 and the intermediate connecting portion 32 of the drive plate 9 and the spring supporting claw 51 of the driven plate 10.
2 is compressed in the direction of rotation. At this time, the torsion spring 12 slides on the drive plate 9 and the piston 8 while moving to the outer peripheral side due to centrifugal force. The outer peripheral side of the torsion spring 12 is directly supported by the outer cylindrical part 33, and the load from the torsion spring 12 is received by the outer cylindrical part 17. Furthermore, the torsion spring 12 is close to or in contact with the axial transmission side surface of the piston 8 in the notch 37.

As described above, by providing the notch at the position corresponding to the torsion spring in the conventional drive plate, the coil diameter of the coil spring can be increased as compared with the conventional one even when the axial size of the damper portion is the same as the conventional one. can do. As a result, the design of the torsion spring 12 is facilitated, and higher functions such as lower rigidity can be realized.

In particular, since the torsion spring 12 is disposed on one side in the axial direction of the friction coupling portion 15 which is the outermost peripheral portion of the piston 8, the coil diameter can be further increased. This is because the outer periphery of the turbine 5 is curved toward the transmission in the axial direction, so that the front cover 3
This is because the outermost peripheral portion of the space between the turbine and the turbine 5 is the largest in the axial direction.

If the coil diameter of the torsion spring does not need to be particularly large, the axial dimension of the damper can be shortened by the thickness of the drive plate. Further, the weight of the drive plate 9 is reduced by the notch 37.

The present invention is not limited to the above embodiment. Further, the present invention is also employed in a lock-up device having a clutch connecting portion forming a plurality of friction surfaces.

[0033]

In the lock-up device for a torque converter according to the present invention, the notch is formed in the drive plate in the lock-up device, so that the diameter of the elastic member is increased by the plate thickness of the drive plate as compared with the related art. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a torque converter to which an embodiment of the present invention is applied.

FIG. 2 is a partial plan view of a piston and a drive plate of the lockup device.

FIG. 3 is a partial plan view of a driven plate, a piston, and a drive plate of the lockup device.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Torque converter 3 Front cover 4 Impeller 5 Turbine 6 Lockup device 8 Piston 9 Drive plate 10 Driven plate 11 Turbine hub 12 Torsion spring 37 Notch

Claims (3)

[Claims] A front cover having a friction surface on the inside;
A torque converter including an impeller that forms a fluid chamber together with the front cover, and a turbine that is disposed in the fluid chamber so as to face the impeller and that secures a space between the impeller and the front cover; A lock-up device for mechanically connecting / disconnecting the front cover and the turbine according to a pressure change in the space, wherein the lock-up device is movable in the space due to a pressure change in the space, and the friction of the front cover is increased. A piston disposed in close proximity to a surface, a mechanism for elastically connecting the piston and the turbine in a rotational direction, and a drive plate fixed to the turbine-side surface of an outer peripheral portion of the piston; A driven plate engaged with the turbine in a relatively non-rotatable manner, the drive plate and the drive plate. A damper mechanism having an elastic member that couples the elastic member to the hood plate in a rotation direction, wherein a cutout is formed at a position corresponding to the elastic member in the drive plate, and a portion of the elastic member on the front cover side. Is a lock-up device for the torque converter, which is arranged in the notch. 2. An outer peripheral edge of the notch has an arc shape, and a corner on a side of the elastic member is chamfered.
A lock-up device for a torque converter according to claim 1. 3. The lock-up device for a torque converter according to claim 1, wherein a surface of the outer peripheral portion of the piston on the turbine side is subjected to a wear-resistant treatment.