Torque converter

A torque converter is provided in which abutment claw portions provided integrally with one of a pair of retaining plates of a dynamic damper mechanism are inserted into a cutout part, a spring retaining member fixed to a clutch piston having the cutout part, wherein the cutout part is formed so that an inner end of the cutout part along a radial direction of an output shaft is positioned further outside than an inside end of a damper spring in the radial direction, and the abutment claw portion is formed so that part of the abutment claw portion overlaps an inertia plate in a projection onto a plane passing through the abutment claw portion and an axis of the output shaft. Such arrangement shortens the axial distance between the clutch piston and the dynamic damper mechanism while maintaining function of the spring retaining member in retaining the damper spring.

TECHNICAL FIELD

The present invention relates to a torque converter that includes a dynamic damper mechanism provided in a torque transmission path via which, when a lockup clutch having a clutch piston is connected, torque is transmitted between the clutch piston and an output shaft, the clutch piston being capable of being frictionally connected to a transmission cover joined to a pump impeller, the dynamic damper mechanism including a pair of retaining plates arranged with a gap in an axial direction of the output shaft while rotating together with a rotation transmitting member forming part of the torque transmission path, an inertial rotating body having an inertia plate sandwiched between the retaining plates, and a dynamic damper spring provided between the retaining plate and the inertia plate, and a damper mechanism disposed in the torque transmission path, the damper mechanism being formed from a plurality of damper springs, a spring retaining member fixed to the clutch piston while having spring cover portions formed into an arc-shaped cross section so as to retain the damper springs between the spring cover portions and the clutch piston and a plurality of cutout parts disposed between the spring cover portions, and a plurality of abutment claw portions provided integrally with one of the pair of retaining plates so as to be inserted into the cutout part and sandwich the damper spring between the abutment claw portion and the spring retaining member.

BACKGROUND ART

Such a torque converter is known from Patent Document 1. In this arrangement, of a pair of retaining plates, an abutment claw part provided integrally with the retaining plate on a clutch piston side is inserted into a cutout part of a spring retaining member, and this abutment claw part is formed so as to be inclined outward along the radial direction of the clutch piston in going toward the clutch piston side.

RELATED ART DOCUMENTS

Patent Documents

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In order to make the clutch piston and the torque converter compact in the axial direction, it is desirable that the axial distance between the clutch piston and a dynamic damper mechanism is shortened, but in the arrangement disclosed by Patent Document 1 above, among the pair of retaining plates, since the abutment claw part is formed integrally with the retaining plate on the clutch piston side, and this abutment claw part is formed so as to be inclined and extend toward the clutch piston side, if the axial distance between the clutch piston and the dynamic damper mechanism is shortened, in order to avoid the abutment claw part interfering with a spring cover part for the spring retaining member, it is necessary to dispose the abutment claw part further inward in the radial direction of the output shaft. By so doing, it becomes necessary to dispose the inner end along the radial direction of the cutout part, which is formed in the spring retaining member so that the abutment claw part is inserted therethrough, further inward along the radial direction, and there is a possibility that the function of the spring retaining member in retaining a damper spring will be degraded.

The present invention has been accomplished in light of such circumstances, and it is an object thereof to provide a torque converter that enables the axial distance between a clutch piston and a dynamic damper mechanism to be shortened while maintaining the function of a spring retaining member in retaining a damper spring.

Means for Solving the Problems

In order to attain the above object, according to a first aspect of the present invention, there is provided a torque converter comprising a dynamic damper mechanism provided in a torque transmission path via which, when a lockup clutch having a clutch piston is connected, torque is transmitted between the clutch piston and an output shaft, the clutch piston being capable of being frictionally connected to a transmission cover joined to a pump impeller, the dynamic damper mechanism comprising a pair of retaining plates arranged with a gap in an axial direction of the output shaft while rotating together with a rotation transmitting member forming part of the torque transmission path, an inertial rotating body having an inertia plate sandwiched between the retaining plates, and a dynamic damper spring provided between the retaining plate and the inertia plate, and a damper mechanism disposed in the torque transmission path, the damper mechanism being formed from a plurality of damper springs, a spring retaining member fixed to the clutch piston while having a plurality of spring cover portions formed into an arc-shaped cross section so as to retain the damper springs between the spring cover portions and the clutch piston and a plurality of cutout parts disposed between the spring cover portions, and a plurality of abutment claw portions provided integrally with one of the pair of retaining plates so as to be inserted into the cutout part and sandwich the damper spring between the abutment claw portion and the spring retaining member, characterized in that the cutout part is formed so that an inner end of the cutout part along a radial direction of the output shaft is positioned further outside than an inside end of the damper spring in the radial direction, and the abutment claw portion is formed so that part of the abutment claw portion overlaps the inertia plate in a projection onto a plane passing through the abutment claw portion and an axis of the output shaft.

Further, according to a second aspect of the present invention, in addition to the first aspect, a rotation restricting hole housing part of the abutment claw portion and extending lengthwise in a peripheral direction is formed in the inertia plate so that abutment of the abutment claw portion against an end part in the peripheral direction of the rotation restricting hole restricts the relative rotational angle between the pair of retaining plates and the inertial rotating body.

According to a third aspect of the present invention, in addition to the second aspect, part of the other retaining plate of the pair of retaining plates is disposed within the rotation restricting hole and abuts against and is fixed by swaging to the abutment claw portion.

Moreover, according to a fourth aspect of the present invention, there is provided a torque converter comprising a dynamic damper mechanism provided in a torque transmission path via which, when a lockup clutch having a clutch piston is connected, torque is transmitted between the clutch piston and an output shaft, the clutch piston being capable of being frictionally connected to a transmission cover joined to a pump impeller, the dynamic damper mechanism comprising a pair of retaining plates arranged with a gap in an axial direction of the output shaft therebetween while rotating together with a rotation transmitting member forming part of the torque transmission path, an inertial rotating body having an inertia plate sandwiched between the retaining plates, and a dynamic damper spring provided between the retaining plate and the inertia plate, and a damper mechanism disposed in the torque transmission path, the damper mechanism being formed from a plurality of damper springs, a spring retaining member fixed to the clutch piston while having a plurality of spring cover portions formed into an arc-shaped cross section so as to retain the damper springs between the spring cover portions and the clutch piston, and a plurality of abutment claw portions provided integrally with one of the pair of retaining plates so as to sandwich the damper spring between the abutment claw portion and the spring retaining member, characterized in that the spring cover portion is formed so that at least part of the spring cover portion is positioned further outside in a radial direction than an inside end of the damper spring, and the abutment claw portion, which can abut against the damper spring outside, along the radial direction, the spring cover portion, is formed so that part of the abutment claw portion overlaps the inertia plate in a projection onto a plane passing through the abutment claw portion and an axis of the output shaft.

Effects of the Invention

In accordance with the first aspect of the present invention, since the inner end, along the radial direction of the output shaft, of the cutout part is present further outside than the inside end of the damper spring in the radial direction, and part of the abutment claw portion overlaps the inertia plate on a projection onto a plane passing through the abutment claw portion and the axis of the output shaft, it is possible to dispose the abutment claw portion further outside in the radial direction of the output shaft while avoiding any interference with the spring cover portion, and it is possible to shorten the axial distance between the clutch piston and the dynamic damper mechanism while maintaining the function of the spring retaining member in retaining the damper spring.

Furthermore, in accordance with the second aspect of the present invention, the relative rotational angle between the pair of retaining plates and the inertial rotating body is restricted with a simple arrangement in which part of the abutment claw part is housed in the rotation restricting hole formed in the inertia plate, thus preventing an excessive load from acting on the dynamic damper spring of the dynamic damper mechanism.

In accordance with the third aspect of the present invention, since of the pair of retaining plates, part of the retaining plate on the side where the abutment claw part is not provided is abutted against and fixed by swaging to the abutment claw part within the rotation restricting hole, it is unnecessary to use a spacer disposed so as to be present between the pair of retaining plates, thereby achieving a reduction in cost.

Furthermore, in accordance with the fourth aspect of the present invention, since at least part of the spring cover part is present further outside, in the radial direction of the output shaft, than the inside end of the damper spring, and part of the abutment claw part, which can abut against the damper spring outside the spring cover part along the radial direction, overlaps the inertia plate in a projection onto a plane passing through the abutment claw part and the axis of the output shaft, it is possible to maintain the function of the spring retaining member in retaining the damper spring while avoiding any interference between the abutment claw part and the spring cover portion, and shorten the axial distance between the clutch piston and the dynamic damper mechanism.

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

MODES FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are explained below by reference to the attached drawings.

First Embodiment

A first embodiment of the present invention is explained by reference toFIG. 1toFIG. 5; first, inFIG. 1, this torque converter includes a pump impeller11, a turbine runner12disposed so as to oppose the pump impeller11, and a stator13disposed between inner peripheral parts of the pump impeller11and the turbine runner12, a circulation circuit15through which hydraulic oil circulates being formed as shown by an arrow14between the pump impeller11, the turbine runner12, and the stator13.

The pump impeller11has a bowl-shaped pump shell16, a plurality of pump blades17provided on an inner face of the pump shell16, a pump core ring18linking the pump blades17, and a pump hub19fixed to an inner peripheral part of the pump shell16by for example welding, an oil pump (not illustrated) supplying hydraulic oil to the torque converter being operatively linked to the pump hub19.

Furthermore, a bowl-shaped transmission cover20covering the turbine runner12from the outside is joined by welding to an outer peripheral part of the pump shell16, a ring gear21is fixed by welding to an outer peripheral part of the transmission cover20, and a drive plate22is fastened to the ring gear21. Moreover, a crankshaft23of a vehicle engine E is coaxially fastened to the drive plate22, and rotational power is inputted from the vehicle engine E into the pump impeller11.

The turbine runner12has a bowl-shaped turbine shell24, a plurality of turbine blades25provided on an inner face of the turbine shell24, and a turbine core ring26linked to the turbine blades25.

An end part of an output shaft27transmitting rotational power from the vehicle engine E to a transmission, which is not illustrated, is supported, via a bearing bush28, on a bottomed cylindrical support tube portion20aintegrally provided on a center part of the transmission cover20. The output shaft27is spline joined to an output hub29disposed at a position spaced in the axial direction from the pump hub19, and a needle thrust bearing30is disposed between the output hub29and the transmission cover20.

The stator13has a stator hub31disposed between the pump hub19and the output hub29, a plurality of stator blades32provided on the outer periphery of the stator hub31, and a stator core ring33linking the outer periphery of the stator blades32, a thrust bearing34is disposed between the pump hub19and the stator hub31, and a thrust bearing35is disposed between the output hub29and the stator hub31.

A one-way clutch37is disposed between the stator hub31and a stator shaft36relatively rotatably surrounding the output shaft27rotating together with the output hub29, and the stator shaft36is non-rotatably supported on a transmission case (not illustrated).

A clutch chamber38communicating with the circulation circuit15is formed between the transmission cover20and the turbine shell24. Housed within the clutch chamber38are a lockup clutch40, an inertial rotating body56rotatably supported on the outer periphery of the output hub29, and a spring holder42A sandwiching part of the inertial rotating body56from opposite sides while enabling relative rotation with respect to the inertial rotating body56in a restricted range.

The lockup clutch40has a clutch piston43that can be frictionally connected to the transmission cover20and can switch between a connected state in which the clutch piston43is frictionally connected to the transmission cover20and a non-connected state in which the frictional connection is released, and an inner peripheral part of the clutch piston43formed into a disk shape is slidably supported on the output hub29so that it can move in the axial direction.

The interior of the clutch chamber38is divided by the clutch piston43into an inside chamber38aon the turbine runner12side and an outside chamber38bon the transmission cover20side, an oil groove44formed in the output hub29so as to be adjacent to the needle thrust bearing30communicates with the outside chamber38b, and the oil groove44communicates with the interior of the cylindrical output shaft27. Furthermore, an oil passage45communicating with an inner peripheral part of the circulation circuit15is formed between the pump hub19and the stator shaft36. The oil pump and an oil reservoir (not illustrated) are alternately connected to the oil groove44and the oil passage45.

When the vehicle engine E is idling or in a very low speed operating range, hydraulic oil is supplied from the oil groove44to the outside chamber38b, and hydraulic oil is guided out from the oil passage45; in this state the outside chamber38bhas a higher pressure than that of the inside chamber38a, the clutch piston43is pushed toward the side on which it moves away from an inner face of the transmission cover20, and the lockup clutch40attains a non-connected state. In this state, relative rotation between the pump impeller11and the turbine runner12is allowed, the pump impeller11is rotated by the vehicle engine E, hydraulic oil within the circulation circuit15thereby circulates within the circulation circuit15as shown by the arrow14in sequence from the pump impeller11to the turbine runner12and then to the stator13, and rotational torque of the pump impeller11is transmitted to the output shaft27via the turbine runner12, the spring holder42A, and the output hub29.

In a state in which there is amplification of torque between the pump impeller11and the turbine runner12the accompanying reaction force is borne by the stator13, and the stator13is fixed by the locking function of the one-way clutch37. Furthermore, when the amplification of torque is finished, the stator13rotates together with the pump impeller11and the turbine runner12in the same direction while making the one-way clutch37idle by reversing the direction of the torque that the stator13receives.

When such a torque converter attains a coupled state or a nearly coupled state, the connected states between the oil groove44and oil passage45and the oil pump and oil reservoir are switched over so that hydraulic oil is supplied from the oil passage45to the inside chamber38aand hydraulic oil is guided out from the oil groove44. As a result, the inside chamber38aof the clutch chamber38has a higher pressure than that of the outside chamber38b, the difference in pressure pushes the clutch piston43toward the transmission cover20side, an outer peripheral part of the clutch piston43is pressed against the inner face of the transmission cover20and is frictionally connected to the transmission cover20, and the lockup clutch40attains a connected state.

When the lockup clutch40has attained the connected state, the torque transmitted from the vehicle engine E to the transmission cover20is mechanically transmitted to the output shaft27via a torque transmission path46A, which includes the clutch piston43, the spring holder42A, and the output hub29; at least one (one in this embodiment) damper mechanism47A is disposed in the torque transmission path46A, and a dynamic damper mechanism48A is attached thereto.

Referring in addition toFIG. 2, the damper mechanism47A is formed by disposing a plurality of, for example four, coil-shaped damper springs49at equal intervals in the peripheral direction between the spring holder42A and a spring retaining member51fixed to the clutch piston43.

An annular housing recess part50is formed in a face, on the side opposite to the transmission cover20, of an outer peripheral part of the clutch piston43, and the spring retaining member51retaining the damper springs49, which are housed within the housing recess part50at equal intervals in the peripheral direction, between itself and the clutch piston43is fixed to the clutch piston43.

The spring retaining member51is formed so as to integrally have a ring plate portion51adisposed coaxially with the clutch piston43while having an outer periphery substantially corresponding to the inner periphery of the housing recess part50, a spring cover portion51bformed into an arc-shaped cross section covering the inside of the damper spring49along the radial direction of the clutch piston43, connected to four positions, equally spaced in the peripheral direction, of the outer periphery of the ring plate portion51a, and formed lengthwise along the peripheral direction of the clutch piston43, and a spring abutment portion51cdisposed between the spring cover portions51band connected to the outer periphery of the ring plate portion51aso as to project further outward in the radial direction than the spring cover portion51b, the ring plate portion51abeing fixed to the clutch piston43by means of a plurality of rivets52.

The spring abutment portions51care disposed between the four damper springs49, and when the lockup clutch40is in a non-connected state, the spring abutment portions51cabut against opposite end parts of the damper spring49.

Referring in addition toFIG. 3, the dynamic damper mechanism48A is formed by disposing a plurality of, for example six, coil-shaped dynamic damper springs57between the inertial rotating body56and the spring holder42A rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46A.

The spring holder42A is formed from a pair of retaining plates54and55relatively non-rotatably linked to each other. The retaining plates54and55are disposed with a gap therebetween in the axial direction of the output shaft27while rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46A, and of the pair of retaining plates54and55the retaining plate54on the turbine runner12side is fixed, by means of a plurality of rivets53, to the output hub29together with the inner peripheral part of the turbine shell24of the turbine runner12.

The inertial rotating body56is formed from a disk-shaped inertia plate58and a weight-adding member59, the disk-shaped inertia plate58being sandwiched between the pair of retaining plates54and55forming the spring holder42A and having its inner peripheral part rotatably supported on the output hub29, and the weight-adding member59being fixed to the outer periphery of the inertia plate58by means of a rivet60.

Spring-retaining portions54aand55afor retaining the dynamic damper spring57are formed at a plurality of, for example four, locations equally spaced in the peripheral direction of the retaining plates54and55, part of the dynamic damper spring57facing the exterior. A spring housing hole61housing part of the dynamic damper spring57is formed in a portion, corresponding to the spring-retaining portions54aand55a, of the inertia plate58so that opposite end parts, along the peripheral direction of the inertia plate58, of the spring housing hole61abut against opposite end parts of the dynamic damper spring57when the lockup clutch40is in a non-connected state.

The inertia plate58is formed so that its outer peripheral part projects further outward in the radial direction than the retaining plates54and55, and the weight-adding member59is fixed to the outer peripheral part of the inertia plate58.

Cylindrical spacers63each inserted into elongated holes62provided at a plurality of, for example four, locations equally spaced in the peripheral direction of the inertia plate58are disposed between the pair of retaining plates54and55on the inside, along the radial direction of the inertial rotating body56, of the spring housing hole61, and cylindrical spacers65each inserted into elongated holes64provided at a plurality of, for example four, locations equally spaced in the peripheral direction of the inertia plate58are disposed between the pair of retaining plates54and55on the outside, along the radial direction of the inertial rotating body56, of the spring housing hole61. The retaining plates54and55are linked by means of rivets66and67extending through the spacers63and65respectively. That is, the inertia plate58can rotate relative to the spring holder42A in a restricted range via which the spacers63and64move within the elongated holes62and64.

Provided integrally with one of the pair of retaining plates54and55forming the spring holder42A, in this embodiment, of the retaining plates54and55, the retaining plate54on the side opposite to the clutch piston43of the lockup clutch40, are a plurality of abutment claw portions54bsandwiching the damper spring49between themselves and the spring abutment portion51cof the spring retaining member51. The damper mechanism47A is formed by disposing the damper spring49between the spring abutment portion51cof the spring retaining member51fixed to the clutch piston43and the abutment claw portion54bof the retaining plate54of the spring holder42A.

In this embodiment, the abutment claw portions54b, of which there are the same number as for the four damper springs49, are bent so as to protrude toward the side opposite to the damper spring49from the outer periphery of the retaining plate54, and are provided integrally with the retaining plate54so as to extend from the bent part in a direction along the axis of the output shaft27. Moreover, it is desirable that the extremity of the abutment claw portion54bpasses through a cross section center C of the damper spring49or is disposed further outward than the cross section center C in the radial direction of the output shaft27. Furthermore, of the pair of retaining plates54and55, the plate thickness of the retaining plate54on the side on which the abutment claw portion54bis provided is set larger than the plate thickness of the other retaining plate55.

Referring toFIG. 2, a plurality of cutout parts70disposed between the plurality of spring cover portions51bare formed in the spring retaining member51fixed to the clutch piston43, the abutment claw portion54bbeing inserted through the cutout part70.

The cutout parts70are formed at a plurality of, for example four, locations equally spaced in the peripheral direction of the spring retaining member51so as to be long in the peripheral direction and open toward the extremity side of the spring cover portion51b. Moreover, the cutout part70is formed in the spring retaining member51so that an inner end70aof the cutout part70along the radial direction of the output shaft27is positioned further outside than an inside end49aof the damper spring49in the radial direction. That is, as shown inFIG. 1, the inner end70aof the cutout part70is disposed at a position further outside along the radial direction than a virtual straight line L passing through the inside end49aof the damper spring49and extending in parallel with the axis of the output shaft27on a projection onto a plane passing through the abutment claw portion54band the axis of the output shaft27.

On the other hand, the spring abutment portion51cis disposed so as to be positioned in a middle part in the peripheral direction of the cutout part70when viewed from the spring holder42A side, and a recess part71for forming the spring cover portion51binto an arc-shaped cross section so as to cover the damper spring49is formed in opposite sides of a base part of the spring abutment portion51cso as to communicate with the cutout part70.

The abutment claw portion54bis, as clearly shown inFIG. 1, bendingly formed so that part of the abutment claw portion54boverlaps the inertia plate58on a projection onto a plane passing through the abutment claw portion54band the axis of the output shaft27, and in this embodiment as shown inFIG. 1andFIG. 4a rotation restricting hole72extending lengthwise in the peripheral direction is formed in the inertia plate58, the abutment claw portion54bbeing inserted through the rotation restricting hole72so that part thereof is housed in the rotation restricting hole72.

Moreover, as shown inFIG. 5the rotation restricting hole72is formed so as to restrict the relative rotational angle between the pair of retaining plates54and55and the inertial rotating body56by the abutment claw portion54babutting against an end part, in the peripheral direction, of the rotation restricting hole72.

When the lockup clutch40attains a connected state and the clutch piston43and the spring retaining member51rotate, the spring abutment portion51ccompresses the damper spring49between itself and the abutment claw portion54b, and power is transmitted from the damper spring49to the output shaft27via the spring holder42A connected to the abutment claw portion54band the output hub29. That is, torque is mechanically transmitted between the clutch piston43and the output shaft27via the torque transmission path46A.

The operation of the first embodiment is now explained. The damper mechanism47A is formed from the plurality of damper springs49, the spring retaining member51, and the plurality of abutment claw portions54b. The spring retaining member51is fixed to the clutch piston43while having the plurality of spring cover portions51bformed into an arc-shaped cross section so as to retain the damper springs49between itself and the clutch piston43. The plurality of abutment claw portions54bare provided integrally with one retaining plate54of the pair of retaining plates54and55forming part of the dynamic damper mechanism48A and sandwiching the inertia plate58of the inertial rotating body56, and sandwich the damper spring49between themselves and the spring retaining member51. The inner end70a, along the radial direction of the output shaft27, of the cutout part70formed in the spring retaining member51so that the abutment claw portion54bis inserted through the cutout part70is disposed further outside than the inside end49aof the damper spring49in the radial direction, and the abutment claw portion54bis formed so that part of the abutment claw portion54boverlaps the inertia plate58on a projection onto a plane passing through the abutment claw portion54band the axis of the output shaft27. It is therefore possible to dispose the abutment claw portion54bfurther outside in the radial direction of the output shaft27while avoiding any interference with the spring cover portion51b, and it is possible to shorten the axial distance between the clutch piston43and the dynamic damper mechanism48A while maintaining the function of the spring retaining member51in retaining the damper spring49.

Moreover, the abutment claw portion54bis provided integrally with the retaining plate54of the pair of retaining plates54and55, which is on the side opposite to the clutch piston43of the lockup clutch40, and it is possible to further shorten the axial distance between the clutch piston43and the dynamic damper mechanism48A.

Furthermore, since the extremity of the abutment claw portion54bis disposed at a position either passing through the cross section center C of the damper spring49or further outside than the cross section center C in the radial direction of the output shaft27, curvature of the damper spring49that makes it protrude toward the radially outward direction of the output shaft27is suppressed when the damper spring49is compressed, and it is possible to suppress the occurrence of a frictional force due to the damper spring49making frictional contact with the clutch piston43.

Moreover, since the rotation restricting hole72housing part of the abutment claw portion54band extending lengthwise in the peripheral direction is formed in the inertia plate58so that the relative rotational angle between the pair of retaining plates54and55and the inertial rotating body56is restricted by the abutment claw portion54babutting against an end part in the peripheral direction of the rotation restricting hole72, it is possible to restrict the relative rotational angle between the pair of retaining plates54and55and the inertial rotating body56with a simple arrangement, and it is possible to prevent an excessive load from acting on the dynamic damper spring57of the dynamic damper mechanism48A.

Second Embodiment

A second embodiment of the present invention is explained by reference toFIG. 6; parts corresponding to those of the first embodiment above are denoted by the same reference numerals and symbols and only illustrated, detailed explanation thereof being omitted.

When the lockup clutch40attains a connected state, torque transmitted from the vehicle engine E to the transmission cover20is mechanically transmitted to the output shaft27via a torque transmission path46B that includes the clutch piston43, a spring holder42B, and the output hub29. At least one (one in this embodiment) damper mechanism47B is disposed in the torque transmission path46B, and a dynamic damper mechanism48B is attached thereto.

The damper mechanism47B is formed by disposing a plurality of, for example four, coil-shaped damper springs49between the spring holder42B and the spring retaining member51fixed to the clutch piston43so as to be equally spaced in the peripheral direction.

The dynamic damper mechanism48B is formed by disposing a plurality of, for example six, coil-shaped dynamic damper springs57between the inertial rotating body56and the spring holder42B rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46B.

The spring holder42B is formed from a pair of retaining plates74and75relatively non-rotatably linked to each other, the retaining plates74and75being disposed with a gap therebetween in the axial direction of the output shaft27while rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46B. Moreover, of the pair of retaining plates74and75, the retaining plate74on the turbine runner12side is fixed to the output hub29together with the inner peripheral part of the turbine shell24of the turbine runner12by means of a plurality of rivets53.

The inertial rotating body56is formed from the disk-shaped inertia plate58sandwiched between the pair of retaining plates74and75forming the spring holder42B and having its inner peripheral part rotatably supported on the output hub29, and the weight-adding member59fixed to the outer periphery of the inertia plate58.

Spring-retaining portions74aand75afor retaining the dynamic damper spring57are formed on a plurality of, for example four, locations, equally spaced in the peripheral direction, of the retaining plates74and75so that part of the dynamic damper spring57faces the exterior. The spring housing hole61housing part of the dynamic damper spring57is formed in a portion, corresponding to the spring-retaining portions74aand75a, of the inertia plate58so that when the lockup clutch40is in a non-connected state opposite end parts, along the peripheral direction of the inertia plate58, of the spring housing hole61abut against opposite end parts of the dynamic damper spring57.

The cylindrical spacers63inserted through the elongated holes62provided at a plurality of, for example four, locations, equally spaced in the peripheral direction, of the inertia plate58are disposed between the pair of retaining plates74and75on the inside of the spring housing hole61along the radial direction of the inertial rotating body56, and the retaining plates74and75are linked by the rivet66extending through the spacer63.

A plurality of abutment claw portions74bare provided integrally with one of the pair of retaining plates74and75forming the spring holder42B, in this embodiment the retaining plate74on the side opposite the clutch piston43of the lockup clutch40among the retaining plates74and75, the abutment claw portions74bbeing inserted through the cutout part70formed in the spring retaining member51fixed to the clutch piston43and sandwiching the damper spring49between themselves and the spring abutment portion51cof the spring retaining member51. The damper mechanism47B is formed by disposing the damper spring49between the spring abutment portion51cof the spring retaining member51fixed to the clutch piston43and the abutment claw portion74bof the retaining plate74of the spring holder42B.

Of the pair of retaining plates74and75, the retaining plate74on the side on which the abutment claw portion74bis provided has a plate thickness that is set larger than the plate thickness of the other retaining plate75.

The abutment claw portion74bis bent so that part of the abutment claw portion74boverlaps the inertia plate58on a projection onto a plane passing through the abutment claw portion74band the axis of the output shaft27, and in this second embodiment a rotation restricting hole76extending lengthwise in the peripheral direction is formed in the inertia plate58, the abutment claw portion74bbeing inserted through the rotation restricting hole76so that part thereof is housed in the rotation restricting hole76.

Moreover, part of the other of the pair of retaining plates74and75, that is, the retaining plate75, is disposed within the rotation restricting hole76and abuts against and is fixed by swaging to the abutment claw portion74b; in this second embodiment a mounting plate portion75bconnectedly provided integrally with the outer periphery of the retaining plate75and disposed within the rotation restricting hole76is disposed within the rotation restricting hole76, abutted against the abutment claw portion74b, and fixed by swaging to the abutment claw portion74busing a rivet77.

In accordance with the second embodiment, in addition to the same effects as those of the first embodiment above being exhibited, since the pair of retaining plates74and75are fixed further outside than the dynamic damper spring57in the radial direction of the output shaft27, it is unnecessary to use a spacer disposed so as to be present between the two retaining plates74and75, thereby achieving a reduction in cost.

Third Embodiment

A third embodiment of the present invention is explained below by reference toFIG. 7; parts corresponding to those of the first embodiment above are denoted by the same reference numerals and symbols and only illustrated, detailed explanation thereof being omitted.

When the lockup clutch40has attained a connected state, the torque transmitted from the vehicle engine E to the transmission cover20is mechanically transmitted to the output shaft27via a torque transmission path46C, which includes the clutch piston43, a spring holder42C, and the output hub29, at least one (one in this embodiment) damper mechanism47C is disposed in the torque transmission path46C, and a dynamic damper mechanism48C is attached thereto.

The damper mechanism47C is formed by disposing a plurality of, for example four, coil-shaped damper springs49at equal intervals in the peripheral direction between the spring holder42C and a spring retaining member51fixed to the clutch piston43.

The dynamic damper mechanism48C is formed by disposing a plurality of, for example six, coil-shaped dynamic damper springs57between the inertial rotating body56and the spring holder42C rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46C.

The spring holder42C is formed from a pair of retaining plates84and85forming part of the torque transmission path46C, the retaining plates84and85being disposed with a gap therebetween in the axial direction of the output shaft27while rotating together with the output hub29, which is a rotation transmitting member forming part of the torque transmission path46C. Moreover, of the pair of retaining plates84and85, the retaining plate84on the turbine runner12side is fixed to the output hub29together with the inner peripheral part of the turbine shell24of the turbine runner12by means of a plurality of rivets53.

The inertial rotating body56is formed from the disk-shaped inertia plate58and the weight-adding member59, the disk-shaped inertia plate58being sandwiched between the pair of retaining plates84and85forming the spring holder42C and having its inner peripheral part rotatably supported on the output hub29, and the weight-adding member59being fixed to the outer periphery of the inertia plate58.

Spring-retaining portions84aand85afor retaining the dynamic damper spring57are formed at a plurality of, for example four, locations equally spaced in the peripheral direction of the retaining plates84and85, part of the dynamic damper spring57facing the exterior. The spring housing hole61housing part of the dynamic damper spring57is formed in a portion, corresponding to the spring-retaining portions84aand85a, of the inertia plate58so that opposite end parts, along the peripheral direction of the inertia plate58, of the spring housing hole61abut against opposite end parts of the dynamic damper spring57when the lockup clutch40is in a non-connected state.

The cylindrical spacers63each inserted into the elongated holes62provided at a plurality of, for example four, locations equally spaced in the peripheral direction of the inertia plate58are disposed between the pair of retaining plates84and85on the inside, along the radial direction of the inertial rotating body56, of the spring housing hole61, and the cylindrical spacers65inserted into the elongated holes64provided at a plurality of, for example four, locations equally spaced in the peripheral direction of the inertia plate58are disposed between the pair of retaining plates84and85on the outside, along the radial direction of the inertial rotating body56, of the spring housing hole61. The retaining plates84and85are linked by means of the rivets66and67extending through the spacers63and65.

A plurality of abutment claw portions85bare provided integrally with one of the pair of retaining plates84and85forming the spring holder42C, in this embodiment the retaining plate85on the clutch piston43side of the lockup clutch40among the retaining plates84and85, the abutment claw portions85bbeing inserted through the cutout part70formed in the spring retaining member51fixed to the clutch piston43and sandwiching the damper spring49between themselves and the spring abutment portion51cof the spring retaining member51. The damper mechanism47C is formed by disposing the damper spring49between the spring abutment portion51cof the spring retaining member51fixed to the clutch piston43and the abutment claw portion85bof the retaining plate85of the spring holder42C.

Of the pair of retaining plates84and85, the retaining plate85on the side on which the abutment claw portion85bis provided has a plate thickness that is set larger than the plate thickness of the other retaining plate84.

The abutment claw portion85bis bent so that part of the abutment claw portion85boverlaps the inertia plate58on a projection onto a plane passing through the abutment claw portion85band the axis of the output shaft27, and in this third embodiment a rotation restricting hole86extending lengthwise in the peripheral direction is formed in the inertia plate58, part of the abutment claw portion85bbeing housed in the rotation restricting hole86. That is, an intermediate part of the abutment claw portion85bis bendingly formed so as to protrude toward the side opposite to the damper mechanism47C, and the intermediate bent part of the abutment claw portion85bis housed in the rotation restricting hole86.

In accordance with the third embodiment, in spite of the abutment claw portion85bbeing provided integrally with, of the pair of retaining plates84and85, the retaining plate85on the clutch piston43side of the lockup clutch40, in the same manner as in the first embodiment the axial distance between the clutch piston43and the dynamic damper mechanism48C can be shortened while maintaining the function of the spring retaining member51in retaining the damper spring49.

Fourth Embodiment

A fourth embodiment of the present invention is explained by reference toFIG. 8andFIG. 9; parts corresponding to those of the first to third embodiments above are denoted by the same reference numerals and symbols and only illustrated, detailed explanation thereof being omitted.

When the lockup clutch40has attained a connected state, the torque transmitted from the vehicle engine E to the transmission cover20is mechanically transmitted to the output shaft27via the torque transmission path46A, which includes the clutch piston43, the spring holder42A, and the output hub29, at least one (one in this embodiment) damper mechanism47D is disposed in the torque transmission path46A, and the dynamic damper mechanism48A is attached thereto.

The damper mechanism47D is formed by disposing a plurality of, for example four, coil-shaped damper springs49at equal intervals in the peripheral direction between the spring holder42A and a spring retaining member91fixed to the clutch piston43.

The annular housing recess part50is formed in a face, on the side opposite to the transmission cover20, of the outer peripheral part of the clutch piston43, and the spring retaining member91retaining the damper springs49, which are housed within the housing recess part50at equal intervals in the peripheral direction, between itself and the clutch piston43is fixed to the clutch piston43.

The spring retaining member91is formed so as to integrally have a ring plate portion91adisposed coaxially with the clutch piston43while having an outer periphery substantially corresponding to the inner periphery of the housing recess part50, a spring cover portion91bformed into an arc-shaped cross section covering the inside of the damper spring49in the radial direction along the clutch piston43, connected to four positions, equally spaced in the peripheral direction, of the outer periphery of the ring plate portion91a, and formed lengthwise along the peripheral direction of the clutch piston43, and a spring abutment portion91cdisposed between the spring cover portions91band connected to the outer periphery of the ring plate portion91aso as to project further outward in the radial direction than the spring cover portion91b, the ring plate portion91abeing fixed to the clutch piston43by means of a plurality of rivets52.

The spring abutment portions91care disposed between the four damper springs49, and when the lockup clutch40is in a non-connected state, the spring abutment portions91cabut against an end part of the damper springs49on its opposite sides.

Provided integrally with one of the pair of retaining plates54and55forming the spring holder42A of the dynamic damper mechanism48A, in this embodiment, of the retaining plates54and55, the retaining plate54on the side opposite to the clutch piston43of the lockup clutch40, are a plurality of abutment claw portions54bsandwiching the damper spring49between themselves and the spring abutment portion51cof the spring retaining member51.

The spring cover portion91bis formed so that at least part thereof is positioned further outside than the inside end49aof the damper spring49in the radial direction of the output shaft27, and in this embodiment, the entirety of an outer end91baof the spring cover portion91balong the radial direction is positioned at a position further outside along the radial direction than a virtual straight line L passing through the inside end49aof the damper spring49and extending in parallel with the axis of the output shaft27on a projection onto a plane passing through the abutment claw portion54band the axis of the output shaft27, the abutment claw portion54bbeing capable of abutting against the damper spring49outside the spring cover portion91balong the radial direction.

Furthermore, a recess part92for forming the spring cover portion91binto an arc-shaped cross section so as to cover the damper spring49is formed in opposite sides of a base part of the spring abutment portion91c.

The abutment claw portion54bis bendingly formed so that part of the abutment claw portion54boverlaps the inertia plate58on a projection onto a plane passing through the abutment claw portion54band the axis of the output shaft27, the abutment claw portion54bbeing inserted into the rotation restricting hole72, formed in the inertia plate58so as to extend lengthwise in the peripheral direction, so that part of the abutment claw portion54bis housed in the rotation restricting hole72.

When the lockup clutch40attains a connected state and the clutch piston43and the spring retaining member91rotate, the spring abutment portion91ccompresses the damper spring49between itself and the abutment claw portion54b, and power is transmitted from the damper spring49to the output shaft27via the spring holder42A connected to the abutment claw portion54band the output hub29. That is, torque is mechanically transmitted between the clutch piston43and the output shaft27via the torque transmission path46A.

Since the spring retaining member91does not have a function of restricting the relative position in the peripheral direction of the abutment claw portion54bwith respect to the clutch piston43, due to the damper spring49being in a state of intimate contact in the axial direction the relative position in the peripheral direction of the abutment claw portion54bwith respect to the clutch piston43is restricted, and there is the advantage that a high strength is not required for the spring retaining member91and the plate thickness of the spring retaining member91can be reduced.

In accordance with the fourth embodiment also, in the same manner as in the first embodiment, the axial distance between the clutch piston43and the dynamic damper mechanism48A can be shortened while maintaining the function of the spring retaining member91in retaining the damper spring49.

Embodiments of the present invention are explained above, but the present invention is not limited to the above embodiments and may be modified in a variety of ways as long as the modifications do not depart from the spirit and scope thereof.