JP3732015B2 - Torque converter lockup piston - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piston for lockup of a torque converter, and more particularly to a piston using a disk-like member having a cylindrical portion extending in the axial direction on the outer periphery.
[0002]
[Prior art]
The torque converter is a device that has three types of impellers (impeller, turbine, and stator) inside, and transmits torque using internal hydraulic oil. The impeller is fixed to a front cover connected to the input side rotating body, and torque is transmitted to the output side by hydraulic oil flowing from the impeller to the turbine. The lockup device is disposed between the turbine and the front cover, and is a device for directly transmitting torque from the front cover to the output side member by mechanically connecting the front cover and the turbine.
[0003]
Normally, this lockup device is elastically connected to the piston in the rotational direction by a piston that can be pressed against the front cover, a retaining plate fixed to the piston, a torsion spring supported by the retaining plate, and a torsion spring. Driven plate. The driven plate is fixed to a turbine connected to the output side rotating body.
[0004]
The piston is movable in the axial direction due to a hydraulic pressure difference between both axial sides. Then, when the friction facing that is annularly stretched on the outer peripheral portion of the piston contacts the friction surface of the front cover, the torque of the front cover is transmitted to the lockup device.
[0005]
[Problems to be solved by the invention]
Although it is desirable that the friction surface of the front cover is flat, in reality, the friction surface may be swelled by welding or the like. In such a case, even if the frictional face of the piston abuts against the friction surface of the front cover, the annular portion of the piston is so stiff that it cannot follow the change of the friction surface on the front cover side, so the friction performance is descend. As a result, there arises a problem that, for example, vibration cannot be sufficiently absorbed and attenuated when performing slip control.
[0006]
On the other hand, in the lockup device, a structure is known in which a cylindrical portion is provided on the outer periphery of the piston, and the cylindrical portion supports a load when the torsion spring tries to move outward in the radial direction by centrifugal force. In this structure, the rigidity of the annular portion in which the friction facing is stretched by the cylindrical portion is high.
An object of the present invention is to improve the friction performance of a portion in which a cylindrical portion extending in the axial direction is formed on an outer peripheral edge and frictionally connected to another member.
[0007]
[Means for Solving the Problems]
The piston for lockup of the torque converter according to claim 1 is disposed between the front cover of the torque converter and the turbine in the axial direction, and is movable in the axial direction by a change in hydraulic pressure, and is output through a torsion spring. It is a piston that can be connected to. The piston includes a disk-shaped member, a retaining plate, and an annular member. The disc-shaped member has a disc-shaped portion and an annular portion that is formed on the outer peripheral side of the disc-shaped portion and is frictionally engaged with other members. The retaining plate is a member that is fixed to the turbine-side surface of the annular portion and supports the torsion spring, and has a support portion that supports the radially outer side of the torsion spring. The annular member is fixed to the outer peripheral surface of the support portion.
[0008]
In the lockup piston of the torque converter according to the first aspect, the load acting from the torsion spring is supported by fixing the annular member to the outer peripheral surface of the support portion. Since this annular member is a separate member from the disk-shaped member, it does not affect the rigidity of the disk-shaped member. That is, the rigidity of the annular portion is lower than that of the conventional disk-shaped member. In this way, the load performance acting from the torsion spring is sufficiently performed, and the friction performance is improved by reducing the rigidity of the annular portion.
[0009]
According to a second aspect of the present invention, the support portion is an annular outer peripheral wall, and the annular member is tightly fitted to the support portion.
In the torque converter lock-up piston according to claim 2, the annular member is fixed to the support portion by a simple method.
[0010]
According to a third aspect of the present invention, there is provided a lockup piston for a torque converter according to the second aspect, wherein the annular main body disposed radially outward of the support portion and the first and second contacts abutting on both axial sides of the support portion, respectively. And a contact portion.
In the lockup piston of the torque converter according to claim 3, the movement of the annular member in the axial direction with respect to the support portion is restricted by the first contact portion and the second contact portion.
[0011]
According to a fourth aspect of the present invention, there is provided the lockup piston of the torque converter according to the third aspect, wherein the first contact portion is a claw portion extending from the axial front cover side of the annular body and contacting the support portion from the axial front cover side. is there.
6. The torque converter lockup piston according to claim 5, wherein the first abutting portion is formed on the axial front cover side of the annular body and is abutted on the support portion from the axial front cover side. Part.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First embodiment Fig. 1 is a partial longitudinal sectional view of a torque converter 61 in which one embodiment of the present invention is adopted. Here, a sectional view of only the outer peripheral side portion of the torque converter 61 is shown. 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 the figure. Further, R1 in FIG. 3 is the rotation direction of the torque converter 61 and the lockup device 1.
[0013]
The torque converter 61 is a mechanism for transmitting torque from the crankshaft on the engine side to the main drive shaft of the transmission, and includes a front cover 62 fixed to the input side member and three types of impellers (impeller 63, turbine). 67, a torus type torque converter main body and a lockup device 1. The front cover 62 is a disk-shaped member, and an outer peripheral cylindrical portion 66 protruding to the axial transmission side is formed on the outer peripheral portion thereof. The outer peripheral cylindrical portion 66 is fixed to the outer peripheral edge of the impeller shell 64 of the impeller 63 by welding. A plurality of impeller blades 65 are fixed inside the impeller shell 64 in the impeller 63. The turbine 67 is disposed opposite the impeller 63 in the fluid chamber. The turbine 67 includes a turbine shell 68 and a plurality of turbine blades 69 fixed to the impeller side surface of the turbine shell 68.
[0014]
The lockup device 1 is arranged in a space between the front cover 62 and the turbine 67 in the axial direction. The entire lockup device 1 has a disk shape, and divides the aforementioned space in the axial direction. A space between the front cover 62 and the lockup device 1 is a first hydraulic chamber A, and a space between the lockup device 1 and the turbine 67 is a second hydraulic chamber B. When the clutch is disengaged, hydraulic oil is supplied to the first hydraulic chamber A from the inner peripheral side, the hydraulic oil flows radially outward, then flows to the second hydraulic chamber B side, and further, the impeller 63 outlet and the turbine 67 inlet It flows into the torus space from the gap between them. At this time, since the hydraulic pressure in the first hydraulic chamber A becomes higher than the hydraulic pressure in the second hydraulic chamber B, the entire lockup device 1 moves to the axial transmission side (that is, the axial turbine 67 side), and the clutch connection is released. Has been. Subsequently, when the hydraulic oil in the first hydraulic chamber A is drained, the hydraulic pressure in the second hydraulic chamber B becomes higher than the hydraulic pressure in the first hydraulic chamber A, so that the entire lockup device 1 is axially engine-side (that is, the shaft Direction front cover 62 side). As a result, the lockup device 1 is pressed against the friction surface 70 of the front cover 62, and the torque of the front cover 62 is input to the lockup device 1.
[0015]
In addition, the other part of the torque converter 61 which is not illustrated in FIG. 1 has a structure common to a normal torque converter.
As shown in FIGS. 2 to 4, the lockup device 1 mainly includes a disk-shaped member 2, a retaining plate 3, a plurality of torsion springs 4, a driven plate 7, and an annular member 30. Has been.
[0016]
The disk-shaped member 2 is a member that engages and disengages the clutch, and further functions as an input member in the lockup device 1. The disk-shaped member 2 has a disk shape in which a central hole is formed. The disk-shaped member 2 is made of a sheet metal material. The disc-like member 2 is mainly composed of a disc-like portion 11 and an annular portion 12 (friction connecting portion) formed on the outer peripheral side of the disc-like portion 11. As apparent from FIG. 2, the disk-like portion 11 is subjected to drawing processing having irregularities in the axial direction. Further, an inner peripheral cylindrical portion 15 extending toward the axial transmission side is formed on the inner peripheral edge of the disk-shaped portion 11. The inner peripheral cylindrical portion 15 is supported, for example, on an outer peripheral surface of a turbine hub (not shown) so as to be relatively rotatable and movable in the axial direction.
[0017]
The annular portion 12 is an annular shape having a predetermined width in the radial direction, and has a planar shape in which both axial surfaces are surfaces perpendicular to the axial direction. A friction facing 6 is bonded to the front cover side of the annular portion 12. The friction facing 6 faces the friction surface 70 of the front cover 62.
As described above, the annular portion 12 has an annular flat plate shape having a predetermined length in the radial direction, and no protrusion or wall of any shape is formed on the outer peripheral edge thereof. For this reason, the rigidity of the annular portion 12 is greatly reduced if the same material and the same plate thickness are used as compared with the conventional annular portion. For example, it is known by calculation that the rigidity is reduced to 20% compared to the conventional case.
[0018]
The retaining plate 3 is arranged on the axial transmission side of the annular portion 12. The retaining plate 3 is an annular member made of sheet metal. The role of the retaining plate 3 is to hold a torsion spring 4 described later. The main body portion 17 of the retaining plate 3 is fixed to the disk-like member 2 by a plurality of rivets 5 at the inner periphery. A cylindrical portion 18 (support portion) extending toward the axial transmission side is formed on the outer peripheral edge of the main body portion 17. The cylinder part 18 is an annular wall. The cylindrical portion 18 is slightly bent at the tip end inward in the radial direction. In the cylindrical portion 18, outer peripheral side cut and bent portions 21 are formed at equal intervals in the circumferential direction. The outer peripheral cut and bent portion 21 is a portion obtained by cutting and bending the tip of the cylindrical portion 18 inward, and extends radially inward. Further, a first inner peripheral side cut and raised portion 22 is formed in the main body portion 17 corresponding to the outer peripheral side cut and bent portion 21. The first inner peripheral side cut-and-raised portion 22 is a portion cut and raised from the main body portion 17 and extends to the axial transmission side. A hole 25 is formed in the main body portion 17 by the first inner peripheral side cut and raised portion 22. Further, the main body portion 17 is formed with a second inner peripheral side cut-and-raised portion 19 at a position corresponding to between the circumferential directions of the first inner peripheral side cut-and-raised portions 22. The second inner peripheral side cut and raised portion 19 is cut and raised from the main body portion 17 and extends to the axial transmission side. In the cylindrical portion 18, a slit 20 is formed in the circumferential direction between the outer peripheral side cut and bent portion 21 and the first inner peripheral side cut and raised portion 22, that is, a portion corresponding to the second inner peripheral side cut and raised portion 19. The circumferential width of the slit 20 is smaller than the alignment of the torsion spring 4 described later. In addition, the slit 20 is connected to a hole 26 formed by cutting and raising the second inner peripheral side cutting and raising portion 19.
[0019]
The torsion spring 4 is for elastically connecting the disc-like member 2 and the driven plate 7 in the rotational direction. Each torsion spring 4 is disposed between each pair of circumferential directions including the first inner peripheral side cut and raised portion 22 and the outer peripheral side cut and bent portion 21 of the retaining plate 3. As a result, both ends in the circumferential direction of the torsion spring 4 are in contact with and supported by the outer peripheral side cut and bent portion 21 and the first inner peripheral side cut and raised portion 22 as torque transmission engaging portions. Further, the radially outer side of the torsion spring 4 is supported by a cylindrical portion 18 as an outer peripheral wall, and the radially inner side is supported by a second inner peripheral side cut-and-raised portion 19. In this way, the torsion spring 4 is supported by the retaining plate 3 on both sides in the radial direction, the axial engine side, and further both ends in the circumferential direction.
[0020]
Each torsion spring 4 is a coil spring composed of a combination of a large coil spring and a small coil spring. The small coil spring is disposed inside the large coil spring and has a circumferential length shorter than that of the large coil spring. As a result, a two-stage torsion characteristic can be realized when the torsion spring 4 is compressed in the rotational direction. Spring seats 9 are disposed at both circumferential ends of each torsion spring 4. The spring seat 9 is engaged with the outer peripheral side cut and bent portion 21, the first inner peripheral side cut and raised portion 22 and the claw 8 (described later) so as to be able to transmit torque.
[0021]
The driven plate 7 is a disk-shaped member, and is disposed between the disk-shaped member 2 and the turbine 67 in the axial direction. The driven plate 7 has a claw 8 that abuts on both ends of each torsion spring 4 in the circumferential direction on the outer peripheral edge. The claw 8 extends in the axial direction from the gap between the outer peripheral cut and bent portion 21 and the first inner peripheral cut and raised portion 22. The driven plate 7 has an inner peripheral edge extending to the vicinity of the inner peripheral cylindrical portion 15 of the disk-shaped member 2. The driven plate 7 has an inner peripheral portion fixed to a turbine hub (not shown). The driven plate 7 may be of a type that is fixed to the turbine shell on the outer peripheral side.
[0022]
The annular member 30 is disposed on the outer peripheral side of the cylindrical portion 18 of the retaining plate 3. The annular member 30 is a member for supporting the load acting on the outer side in the radial direction by the torsion spring 4 by supporting the outer peripheral side of the cylindrical portion 18. The entire annular member 30 is plate-shaped and cylindrical. The plate thickness of the annular member 30 is smaller than the plate thickness of the disc-like member 2. The annular member 30 has a main body 31 that contacts the outer peripheral surface of the cylindrical portion 18. The main body 31 is tightly fitted to the cylindrical portion 18. An inclined portion 32 that is bent inward is formed on the axial transmission side of the main body 31, and a distal end portion 33 that extends radially inward from the inclined portion 32 is formed. The inclined portion 32 is in contact with the slightly bent tip of the tube portion 18, and the tip portion 33 is located on the axial transmission side of the tip of the tube portion 18. Thereby, the annular member 30 is not movable toward the axial direction engine side with respect to the retaining plate 3. Further, a plurality of claws 34 are formed in the circumferential direction on the axial direction engine side of the main body 31. The claw 34 is bent to the inner peripheral side and is in close contact with the surface of the cylindrical portion 18 on the axial engine side.
[0023]
As described above, the annular member 30 has the inclined portion 32 and the tip portion 33 (second contact portion) in contact with the axial transmission side of the cylindrical portion 18, and the claw 34 (first contact portion) is in the cylindrical shape. The part 18 is in contact with the axial engine side. In other words, the annular member 30 is engaged with the axially opposite surfaces of the cylindrical portion 18, and cannot move in the axial direction with respect to the cylindrical portion 18, that is, the retaining plate 3.
[0024]
As described above, the annular member 30 for supporting the radially outward load from the torsion spring 4 is a separate member from the disk-shaped member 2, and is in contact with the disk-shaped member 2. Not engaged. For this reason, a structure that supports the load from the torsion spring 4 and does not increase the rigidity of the annular portion 12 is realized. The structure of the lockup device 1 will be described from another angle. The disk-shaped member 2, the retaining plate 3, the annular member 30, and the like form a piston 10 that is a member that rotates integrally. The piston 10 functions as an input member of the lockup device 1 as a damper. The driven plate 7 functions as an output member of the damper. The torsion spring 4 functions as an elastic member that connects the input member and the output member in the rotation direction in the damper.
[0025]
Next, the operation will be described.
The torque of the crankshaft from the engine side is input to the front cover 62 via a flexible plate (not shown). As a result, the impeller 63 rotates and hydraulic oil flows from the impeller 63 to the turbine 67. The turbine 67 is rotated by the flow of the hydraulic oil, and the torque of the turbine 67 is output to a main drive shaft (not shown).
[0026]
When the speed ratio of the torque converter 61 increases and the main drive shaft reaches a constant rotational speed, the hydraulic oil in the first hydraulic chamber A between the disc-like member 2 and the front cover 62 passes through the inside of the main drive shaft. Drained. As a result, due to the hydraulic pressure difference between the first hydraulic chamber A and the second hydraulic chamber B, the disc-like member 2 is moved to the front cover 62 side. As a result, the friction facing 6 is pressed against the friction surface 70 of the front cover 62. Thereby, the torque of the front cover 62 is transmitted from the disc-like member 2 to the driven plate 7 via the retaining plate 3 and the torsion spring 4. Further, torque is output from the driven plate 7 to a main drive shaft (not shown). That is, the front cover 62 is mechanically coupled to the turbine 67, and the torque of the front cover 62 is directly output to the main drive shaft (not shown) via the turbine 67.
[0027]
At this time, the lockup device 1 transmits torque and absorbs and attenuates torsional vibration input from the front cover 62. Specifically, when torsional vibration is input from the front cover 62 to the lockup device 1, the torsion spring 4 is compressed between the retaining plate 3 and the driven plate 7. More specifically, the torsion spring 4 is compressed in the circumferential direction between the outer circumferential side cut and bent portion 21 and the first inner circumferential side cut and raised portion 22 and the claw 8 on the opposite side in the circumferential direction. The torsion spring 4 extends to the original state after being compressed and repeats the above operation.
[0028]
As described above, when a torsional vibration is input and the torsion spring 4 repeats compression and extension, the torsion spring 4 is moved radially outward by the centrifugal force and is pressed against the cylindrical portion 18 of the retaining plate 3. Sliding. That is, force is applied to the cylindrical portion 18 from the inside in the radial direction. A portion corresponding to the torsion spring 4 in the cylindrical portion 18 is divided into two in the circumferential direction by the slit 20. For this reason, the degree of concentration of stress when receiving force is lowered. As a result, the life of the retaining plate 3 can be maintained longer even if the plate thickness is made thinner than before. That is, weight reduction of the lockup device 1 is realized.
[0029]
The cylindrical portion 18 is supported on the outer peripheral side by an annular member 30. That is, the radial load acting from the torsion spring 4 is supported by the annular member 30 via the cylindrical portion 18.
As described above, the annular member 30 is engaged with the outer peripheral surface of the cylindrical portion 18 to support the load acting from the torsion spring 4. Since the annular member 30 is a separate member from the disk-shaped member 2 (which rotates integrally but does not have a continuous portion), it does not easily affect the rigidity of the disk-shaped member 2. That is, the rigidity of the annular portion 12 is lower than that of a conventional disk-shaped member (having a cylindrical portion extending in the axial direction from the outer peripheral edge of the annular portion). In this manner, the load acting from the torsion spring 4 is sufficiently supported, and the friction performance is improved by reducing the rigidity of the annular portion 12.
[0030]
Second embodiment In the lockup device 1 shown in Figs. 5 and 6, the annular member 37 is tightly fitted to the outer peripheral surface of the cylindrical portion 18. The effects obtained by the annular member 37 are the same as those in the above embodiment. The main body 38 of the annular member 37 has a cylindrical shape and is in close contact with the outer peripheral surface of the cylindrical portion 18. In this embodiment, the plate thickness of the main body 38 is substantially the same as the plate thickness of the disk-shaped member 2. An engaging portion 39 that protrudes toward the inner peripheral side is formed on the axial transmission side of the main body 38. The engaging part 39 is in contact with the bent tip of the cylindrical part 18. Further, a caulking portion 40 is formed on the inner peripheral side of the main body 38 on the axial direction engine side. A plurality of caulking portions 40 are formed side by side in the circumferential direction. The caulking portion 40 protrudes from the main body 38 toward the inner peripheral side, and is strongly pressed against the axial direction engine side of the cylindrical portion 18. In this way, the annular member 37 is less likely to move in the axial direction with respect to the cylindrical portion 18 because the engaging portion 39 and the caulking portion 40 abut from both sides in the axial direction of the cylindrical portion 18.
[0031]
【The invention's effect】
In the torque converter lock-up piston according to the present invention, the annular member is a separate member from the disk-like member, so that the rigidity of the disk-like member is not affected, and as a result, compared to the conventional disk-like member. In this case, the rigidity of the annular portion is low. In this way, the load performance acting from the torsion spring is sufficiently performed, and the friction performance is improved by reducing the rigidity of the annular portion.
[Brief description of the drawings]
FIG. 1 is a partial vertical cross-sectional schematic view of a torque converter that employs a lock-up clutch as a first embodiment of the present invention.
FIG. 2 is a schematic vertical sectional view of the lockup device.
FIG. 3 is a plan view of the lock-up device.
FIG. 4 is a partial instruction of the lock-up device.
FIG. 5 is a schematic vertical sectional view of a lockup device according to a second embodiment.
FIG. 6 is a plan view of a lockup device according to a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lockup apparatus 2 Disc shaped member 3 Retaining plate 4 Torsion spring 10 Piston 11 Disc shaped part 12 Annular part 18 Cylindrical part 30 Annular member

Claims (5)

A piston that is arranged between the front cover of the torque converter and the turbine in the axial direction, is movable in the axial direction by a change in hydraulic pressure, and is connectable to an output member via a torsion spring;
A disk-shaped member having a disk-shaped part and an annular part formed on the outer peripheral side of the disk-shaped part for frictional engagement with other members;
A retaining plate that is fixed to the turbine-side surface of the annular portion and supports the torsion spring, and has a support portion for supporting the radially outer side of the torsion spring;
An annular member fixed to the outer peripheral surface of the support part;
Torque converter piston for lockup with The support portion is an annular outer peripheral wall;
The annular member is tightly fitted to the support;
The piston for lockup of the torque converter of Claim 1. The annular member includes an annular main body disposed on the outer side in the radial direction of the support portion, and first and second abutting portions that abut on both sides in the axial direction of the support portion, respectively.
The piston for lockup of the torque converter according to claim 2. The first contact portion is a claw portion that extends from the axial front cover side of the annular main body and contacts the support portion from the axial front cover side.
The piston for lockup of the torque converter according to claim 3. The first contact portion is a caulking portion that is formed on the axial front cover side of the annular main body and contacts the support portion from the axial front cover side.
The piston for lockup of the torque converter according to claim 3.

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