JP2014219056A - Lockup device for torque converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of members, the cost and the weight in a lockup device having an intermediate member.SOLUTION: A lockup device includes a piston 30 having a plurality of input side fitting parts 30c protruded to a turbine side on an outer peripheral part, an output member 31 provided on the turbine 6, a plurality of torsion springs 32, and an intermediate member 33. The plurality of torsion springs 32 can be abutted to the input side fitting parts 30c of the piston 30, and elastically connect the input side fitting parts 30c and the output member 31 in a rotation direction. The intermediate member 33 is arranged relatively rotatable to the piston 30 and the torsion spring 32 between the piston 30 and the torsion spring 32 in an axial direction, and allows the two torsion springs 32 to act in series. The intermediate member 33 has circular arc-like slits 33e into which the input side fitting parts 30c of the piston 30 is inserted.

Description

  The present invention relates to a lockup device, and more particularly to a lockup device for transmitting torque from a front cover to a turbine of a torque converter.

  In many cases, the torque converter is provided with a lock-up device for transmitting torque directly from the front cover to the turbine. As shown in Patent Document 1, this type of lockup device includes a piston that can be frictionally connected to a front cover, a drive plate fixed to the piston, a driven plate, a plurality of torsion springs, an intermediate member, have. The driven plate is fixed to the turbine of the torque converter, and is elastically connected to the drive plate in the rotational direction via a plurality of torsion springs.

  In this device, the piston is provided between the front cover and the turbine. When an annular friction member fixed to the outer periphery of the piston is pressed against the friction surface of the front cover, the torque of the front cover is locked up. Is transmitted to the device. Then, torque is transmitted from the lockup device to the turbine. At this time, torque fluctuations input from the engine are absorbed and attenuated by the plurality of torsion springs of the lockup device.

JP 2011-179515 A

  In a torque converter lock-up device, a pair of torsion springs are often configured to act in series in order to increase the twisting angle of the damper mechanism with low rigidity. An intermediate member is provided to cause the pair of torsion springs to act in series. The intermediate member is provided to be rotatable relative to the drive plate and the driven plate, and supports a plurality of torsion springs.

  As described above, the lockup device with low rigidity and a wide torsion angle requires a drive plate fixed to the piston, an intermediate member supporting the torsion spring, and a driven plate fixed to the turbine. The number of parts is large, which hinders cost reduction.

  An object of the present invention is to realize a reduction in cost and weight by reducing the number of members, particularly in a lockup device provided with an intermediate member.

  A torque converter lockup device according to a first aspect of the present invention is a device for transmitting torque from a front cover to a turbine of a torque converter, and includes a piston, an output member, a plurality of elastic members, and an intermediate member. And a member. The piston is movable in the axial direction, has a friction member pressed against the front cover, and has a plurality of engaging portions protruding on the turbine side on the outer peripheral portion. The output member is provided in the turbine. The plurality of elastic members are engageable with the engaging portion of the piston and the output member, and elastically connect the engaging portion of the piston and the output member in the rotation direction. The intermediate member is a member that is disposed so as to be relatively rotatable with respect to the piston and the output member in the axial direction between the piston and the elastic member, and causes at least two of the plurality of elastic members to act in series. The intermediate member has a plurality of arc-shaped slits through which the plurality of engaging portions of the piston are inserted.

  In this apparatus, at least two of the plurality of elastic members act in series by the intermediate member, and the torsion angle is widened. And the engaging part provided in the piston penetrates the arc-shaped slit of the intermediate member and engages with the elastic member. In such a configuration, the torque is transmitted from the front cover to the piston when the friction member is pressed against the front cover. The torque transmitted to the piston is transmitted from the engagement portion to the output member via a plurality of elastic members.

  Here, the engaging portion of the piston passes through the slit of the intermediate member and engages with the elastic member. For this reason, the drive plate in the conventional apparatus becomes unnecessary, and cost reduction and weight reduction can be realized.

  In the torque converter lockup device according to the second aspect of the present invention, in the device according to the first aspect, the piston has a protrusion protruding toward the axial turbine side on the turbine side surface. The intermediate member is positioned in the radial direction by the inner peripheral end abutting against the protrusion.

  Here, the radial positioning of the intermediate member is performed by the intermediate member abutting against the protruding portion of the piston. For this reason, the special structure for positioning becomes unnecessary.

  In the torque converter lockup device according to the third aspect of the present invention, the piston engaging portion is in contact with a part of the slit of the intermediate member in the device of the first side surface, so that the radial positioning of the intermediate member is performed. Has been made.

  Here, the radial positioning of the intermediate member is performed using the engaging portion of the piston and the slit of the intermediate member. For this reason, the special structure for positioning becomes unnecessary.

  In the torque converter lockup device according to the fourth aspect of the present invention, in any of the first to third devices, the output member is formed by bending the turbine shell toward the axial front cover.

  Here, since the output member is constituted by a part of the turbine shell, the driven plate in the conventional apparatus becomes unnecessary. Further, there is no need to weld the driven plate to the turbine shell or to fix the driven plate to the turbine hub by rivets, and the number of parts can be reduced and the configuration can be simplified.

  As described above, according to the present invention, in the lockup device provided with the intermediate member, the drive plate in the conventional device becomes unnecessary, and the cost and weight can be reduced.

1 is a cross-sectional view of a torque converter including a lockup device according to an embodiment of the present invention. FIG. 2 is an enlarged partial view of FIG. 1. The partial front view of FIG.

[Overall configuration of torque converter]
FIG. 1 is a partial sectional view of a torque converter 1 in which a lockup device according to an embodiment of the present invention is employed. 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. OO shown in FIG. 1 is a rotational axis of the torque converter and the lockup device.

  The torque converter 1 includes a front cover 2, a torque converter main body 3, and a lockup device 4. The torque converter body 3 has a torus-shaped fluid working chamber, and the fluid working chamber includes an impeller 5, a turbine 6, and a stator 7.

  The front cover 2 is a disk-shaped member, and a center boss 10 is provided at the inner peripheral end. The center boss 10 is a cylindrical member extending in the axial direction, and is inserted into the center hole of the crankshaft. A plurality of bolts 11 are fixed on the outer peripheral side of the front cover 2 at equal intervals in the circumferential direction. A nut (not shown) screwed into the bolt 11 fixes the outer peripheral portion of the flexible plate (not shown) to the front cover 2.

  The impeller 5 includes an impeller shell 13, a plurality of impeller blades 14 fixed inside the impeller shell 13, and an impeller hub 15 fixed to the inner peripheral portion of the impeller shell 14. The outer peripheral edge of the impeller shell 13 is welded to the tip of the outer peripheral cylindrical portion 2 a formed on the outer peripheral portion of the front cover 2.

  The turbine 6 is disposed to face the impeller 5 in the axial direction. The turbine 6 includes a turbine shell 17, a plurality of turbine blades 18 fixed to the inside of the turbine shell 17, and a turbine hub 19 fixed to the inner peripheral edge of the turbine shell 18. An inner peripheral end portion of the turbine shell 17 is fixed to the turbine hub 19 by a plurality of rivets 20. A spline 19 a that engages with an input shaft (not shown) of the transmission is formed on the inner peripheral surface of the turbine hub 19. Thereby, the turbine hub 19 rotates integrally with the input shaft.

  The stator 7 is disposed between the inner peripheral portion of the impeller 5 and the inner peripheral portion of the turbine 6, and is a mechanism for rectifying the flow of hydraulic oil that returns from the turbine 6 to the impeller 5. The stator 7 has an annular stator shell 22 and a plurality of stator blades 23 provided on the outer peripheral surface of the shell 22. The stator shell 22 is supported by a cylindrical fixed shaft (not shown) via a one-way clutch 24. The fixed shaft extends between the outer peripheral surface of the input shaft and the inner peripheral surface of the impeller hub 15.

  A thrust bush 26 is disposed between the inner peripheral portion of the front cover 2 and the turbine hub 19 in the axial direction. Thrust bearings 27 and 28 are disposed between the turbine hub 19 and the one-way clutch 24 and between the stator 7 and the impeller 5 in the axial direction, respectively.

[Structure of lock-up device 4]
The lockup device 4 is disposed between the turbine 6 and the front cover 2 and is a mechanism for mechanically connecting the two. The lockup device 4 includes a piston 30, an output member 31 formed integrally with the turbine 6, a plurality of torsion springs 32, and an intermediate member 33.

<Piston 30>
The piston 30 is a member for connecting and disconnecting the clutch, and has a disk shape with a center hole formed therein. An inner peripheral cylindrical portion 30 a extending toward the axial transmission side is formed on the inner peripheral edge of the piston 30. The inner peripheral cylindrical portion 30a is supported by the engine outer peripheral surface of the turbine hub 19 so as to be movable in the rotational direction and the axial direction. Note that the piston 30 is restricted from moving toward the transmission in the axial direction by contacting the transmission side surface of the turbine hub 19.

  Further, a seal ring 35 is provided on the outer peripheral surface of the turbine hub 19 on the engine side so as to come into contact with the inner peripheral surface of the inner peripheral cylindrical portion 30a. Thereby, the inner peripheral edge of the piston 30 is sealed. Further, an annular friction coupling portion 30 b is formed on the outer peripheral side of the piston 30. An annular friction facing 36 is fixed to the axially engine side of the friction coupling portion 30b.

  As shown in an enlarged view in FIG. 2, a plurality of input side engaging portions 30 c are formed on the outer peripheral portion of the piston 30. The plurality of input side engaging portions 30c are arranged at equal angular intervals in the circumferential direction, and are formed by bending the outer peripheral portion of the piston 30 to the transmission side. Each input-side engaging portion 30 c can abut on the circumferential end surface of the torsion spring 32.

<Output member 31>
As shown in FIGS. 1 and 2, the output member 31 is formed by bending the outer peripheral portion of the turbine shell 17 to the engine side. The output member 31 is formed with a plurality of output side engaging portions 31a. The plurality of output side engaging portions 31a are arranged at equal angular intervals in the circumferential direction and arranged on the inner peripheral side of the input side engaging portion 30c, and can contact the circumferential end surface of the torsion spring 32. is there.

<Torsion spring 32>
As shown in FIGS. 1 to 3, the torsion spring 32 is supported by an intermediate member 33 and elastically connects the piston 30 and the output member 31 in the rotational direction. Specifically, the torsion spring 32 is disposed at a position where it can come into contact with the input side engaging portion 30c of the piston 30 and the output side engaging portion 31a of the output member 31, and torque is transmitted from the input side engaging portion 30c. Then, this is transmitted to the output side engaging part 31a. Note that two torsion springs 32 of the plurality of torsion springs 32 are arranged so as to act in series by the intermediate member 33.

<Intermediate member 33>
As described above, the intermediate member 33 is a member for causing the pair of torsion springs 32 to act in series, and is a member for supporting the torsion springs 32 in the radial direction and the axial direction. The intermediate member 33 is disposed so as to be rotatable relative to the piston 30 and the output member 31.

  The intermediate member 33 is formed in an annular shape, and as shown in FIG. 2, a positioning portion 33a, an axial restriction portion 33b, a radial restriction portion 33c, and a plurality of intermediate members formed at the inner peripheral end portion. And a joint portion 33d.

  The positioning portion 33a is supported on the outer peripheral surface of the positioning convex portion 30d formed on the piston 30, and is positioned in the radial direction of the intermediate member 33. The positioning convex portion 30d is a portion formed by extruding a part of the piston 30 to the turbine side.

  The axial direction restricting portion 33b is a disc-shaped portion formed on the outer peripheral side of the positioning portion 33a. The axial direction restricting portion 33b is disposed between the torsion spring 32 and the piston 30, and restricts the movement of the torsion spring 32 toward the axial direction engine. Further, as shown in FIG. 3, a plurality of arc-shaped slits 33 e extending in the circumferential direction are formed in the axial direction restricting portion 33 b. The input side engaging portion 30c of the piston 30 penetrates the slit 33e in the axial direction. The input side engaging portion 30c is movable in the rotation direction in the slit 33e. Therefore, the piston 30 and the intermediate member 33 can be rotated relative to each other within an angle range where the slit 33e is formed.

  The radial restricting portion 33c is formed to extend from the outer peripheral portion of the axial restricting portion 33b to the transmission side. The radial restricting portion 33 is formed by bending the outer peripheral portion of the axial restricting portion 33b to the transmission side. The radial restricting portion 33c restricts the torsion spring 32 from protruding outward in the radial direction.

  The plurality of intermediate engaging portions 33d have an outer peripheral side engaging portion 33do and an inner peripheral side engaging portion 33di. The outer peripheral side engaging portion 33do is formed by bending a part of the radial direction restricting portion 33c toward the inner peripheral side and further bending the tip toward the engine side. The inner peripheral side engaging portion 33di is formed by cutting and raising a part of the axial direction restricting portion 33b to the transmission side. These intermediate engaging portions 33d are arranged between the rotation directions of the pair of torsion springs 32 acting in series.

[Torque converter operation]
In the low engine speed region, the piston 30 moves to the transmission side due to the pressure difference between the hydraulic oils on both sides of the piston 30 in the axial direction. That is, the friction facing 36 is separated from the front cover 2 and the lock-up is released. When the lockup is released, torque from the front cover 2 is transmitted from the impeller 5 to the turbine 6 via hydraulic oil.

[Operation of lock-up device]
When the speed ratio of the torque converter 1 increases and the engine speed reaches a constant speed, the hydraulic oil on the engine side of the piston 30 is discharged and the hydraulic pressure on the turbine side of the piston 30 is increased. As a result, the piston 30 is moved to the front cover 2 side, and the friction facing 36 is pressed against the friction surface of the front cover 2. As a result, the torque of the front cover 2 is transmitted to the torsion spring 32 via the input side engaging portion 30 c of the piston 30 and further transmitted to the turbine 6 via the output side engaging portion 31 a of the output member 31. That is, the front cover 2 is mechanically connected to the turbine 6, and the torque of the front cover 2 is directly output to the input shaft of the transmission via the turbine 6.

  Here, one set (two) of torsion springs 32 of the plurality of torsion springs 32 directly act by the intermediate member 33. Therefore, the torsional characteristics of the lockup device 4 can be reduced in rigidity and widened.

[Feature]
(1) The input side engaging portion 30 c formed on the piston 30 passes through the slit 33 e of the intermediate member 33 and engages with the torsion spring 32. For this reason, the drive plate in the conventional apparatus becomes unnecessary, and cost reduction and weight reduction can be realized.

  (2) Since the intermediate member 33 is positioned by the positioning convex portion 30d formed on the piston 30, a special configuration for positioning is not required.

  (3) Since the output member 31 is formed by bending the turbine shell 17 toward the axial front cover, the driven plate in the conventional apparatus is not necessary. Further, there is no need to weld the driven plate to the turbine shell or to fix the driven plate to the turbine hub by rivets, and the number of parts can be reduced and the configuration can be simplified.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and various changes or modifications can be made without departing from the scope of the present invention.

  (1) In the above embodiment, the output member is formed by bending a part of the turbine shell, but the output member may be constituted by a member different from the turbine shell.

  (2) The configuration for positioning the intermediate member 33 in the radial direction is not limited to the above embodiment. For example, instead of the positioning convex portion 30 d of the piston 30, positioning may be performed by bringing the input side engaging portion 30 c of the piston 30 into contact with the outer peripheral side wall surface of the slit 33 e of the intermediate member 33.

DESCRIPTION OF SYMBOLS 1 Torque converter 2 Front cover 4 Lockup device 6 Turbine 17 Turbine shell 30 Piston 30c Input side engaging part 30d Positioning convex part 31 Output member 31a Output side engaging part 32 Torsion spring 33 Intermediate member 33e Slit

Claims (4)

A lockup device for transmitting torque from a front cover to a turbine of a torque converter,
A piston that is movable in the axial direction, has a friction member pressed against the front cover, and has a plurality of engaging portions projecting toward the turbine side on an outer peripheral portion;
An output member provided in the turbine;
A plurality of elastic members that are engageable with the engaging portion of the piston and the output member, and elastically connect the engaging portion of the piston and the output member in a rotation direction;
Between the axial direction of the piston and the elastic member, is arranged to be relatively rotatable with respect to the piston and the output member, and is a member for causing at least two of the plurality of elastic members to act in series, An intermediate member having a plurality of arc-shaped slits through which each of the plurality of engaging portions of the piston is inserted;
Torque converter lockup device with The piston has a protrusion protruding toward the axial turbine side on the turbine side surface,
The intermediate member is positioned in the radial direction by the inner peripheral end abutting against the protrusion.
The lockup device for a torque converter according to claim 1.   2. The torque converter lockup device according to claim 1, wherein the engaging portion of the piston is in contact with a part of the slit of the intermediate member, and the intermediate member is positioned in a radial direction.   4. The torque converter lockup device according to claim 1, wherein the output member is formed by bending a shell of the turbine toward an axial front cover side. 5.

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