JP2002310262A - Lock-up device for hydraulic torque transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase torque transmission capacity and improve the response property of lock-up operation by arranging a damper mechanism of a lock-up device in an outer peripheral part of a space between a front cover and a turbine. SOLUTION: The damper mechanism 60 of the lock-up device 7 consists mainly of a first drive plate 61 having a function for torque transmission and arranged on an outer peripheral side of the space between the front cover 11 and the turbine 22, a driven plate 62, a second drive plate 63, and a torsion spring 64. A piston 74 has a function for connecting and releasing a clutch, is engaged with the front cover 11 so as to move in the axial direction and prevent its move in the direction of rotation by a piston connection mechanism 75, and is provided with a check valve 79 for letting hydraulic fluid flow into a second space 9b only form a first space 9a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock-up device for a hydraulic torque transmission device, and more particularly, to a front cover having a friction surface, an impeller fixed to the front cover and forming a fluid chamber filled with hydraulic oil, and The present invention relates to a lock-up device provided in a fluid torque transmission device including a turbine disposed in a fluid chamber so as to face the impeller.

[0002]

2. Description of the Related Art A torque converter is a type of fluid torque transmission device having three types of impellers (impeller, turbine, and stator) inside and transmitting torque through internal working oil. This torque converter is often provided with a lock-up device.

The lock-up device is arranged in a space between the turbine and the front cover, and is a mechanism for directly transmitting torque from the front cover to the turbine by mechanically connecting the front cover and the turbine. is there.

Normally, this lockup device has a disk-shaped piston that can be pressed against a front cover, a retaining plate fixed to the outer peripheral portion of the piston, and a rotational direction and an outer peripheral side by the retaining plate. It has a torsion spring that is supported and a driven plate that supports both ends of the torsion spring in the rotation direction. The driven plate is fixed to a turbine shell or the like of the turbine.

In such a lock-up device, a lock-up device having two friction surfaces to increase the torque transmission capacity has already been provided. One of such devices includes a damper mechanism coupled to a turbine, a friction connection formed at an input portion of the damper mechanism, and a piston for pressing the friction connection to a front cover. There is something.

In this type of device, it is desirable to arrange the damper mechanism on the outer peripheral portion of the space between the front cover and the turbine and increase the length and number of torsion springs to improve the torsional vibration absorbing performance. .

For example, a lock-up device disclosed in Japanese Patent Publication No. 11-509611 discloses a driven plate connected to a turbine, a torsion spring supported at both ends in a rotational direction, a torsion spring supported by the turbine, and its rotation. It has a damper mechanism composed of a guide ring engaged with both ends in the direction and a drive plate engaged with the guide ring so as to be relatively non-rotatable and movably in the axial direction. A friction connecting portion for transmitting torque is formed on the inner peripheral side of the drive plate, and is configured to be pressed against a front cover by a piston.

[0008]

In the prior art, the torsion spring of the lock-up device is disposed on the outer peripheral portion of the space between the front cover and the turbine, so that the torsional vibration absorbing performance is improved. However, the torque transmission capacity of the lock-up device cannot be sufficiently increased because the friction coupling portion is disposed on the inner peripheral side of the torsion spring.

Further, the inner peripheral edge of the piston is supported in a sealed state on the outer peripheral surface of the turbine hub, but the hydraulic oil can flow in the outer peripheral portion of the piston in the axial direction when the clutch is released. A gap is secured. Due to this gap, in the clutch disengaged state, the hydraulic oil flows from the front cover side of the piston to the turbine side, and further flows into the torque converter body. As a result, the friction coupling portion of the lock-up device is cooled, and sufficient hydraulic oil is supplied to the torque converter body.

However, in the initial stage of shifting from the clutch disengaged state to the clutch engaging operation, hydraulic oil flows from the turbine from the turbine side to the front cover side from the gap. As a result, a sufficiently large hydraulic pressure difference is not obtained between the turbine side and the front cover side of the piston, and the responsiveness of the lock-up operation is reduced.

An object of the present invention is to increase the torque transmission capacity in a lock-up device in which a torsion spring of a damper mechanism is arranged on an outer peripheral portion of a space between a front cover and a turbine.

Another object of the present invention is to improve the responsiveness of a lock-up operation.

[0013]

According to a first aspect of the present invention, there is provided a lock-up device for a hydraulic torque transmission device, comprising: a front cover having a friction surface; and a fluid chamber fixed to the front cover and filled with hydraulic oil. A lock-up device provided in a hydraulic torque transmission device including an impeller and a turbine disposed in the fluid chamber so as to face the impeller, wherein a friction is formed on an outer peripheral portion of a space between the front cover and the turbine. A drive member having a first frictional connection portion disposed opposite to the surface and a second frictional connection portion disposed away from the first frictional connection portion on the turbine side; A driven member extending between the connection portion and the second frictional connection portion, and a drive member and a driven member disposed between the first frictional connection portion and the second frictional connection portion are elastically moved in a rotational direction. A plurality of elastic members for connecting the first member and a drive member and the turbine so as to rotate integrally with the front cover. The first member is pressed against the second member to connect the first member to the friction surface. And a piston for pressing.

In this lockup device, the piston is
When the drive member moves to the engine side, the drive member comes into pressure contact with a second frictional connection portion formed on the turbine side of the drive member to move the entire drive member to the engine side. Then, the first friction connecting portion formed on the engine side of the drive member is pressed against the friction surface of the front cover. Thus, the torque input to the front cover is transmitted from the lock-up device to the drive member via the first and second frictional connection portions, and further transmitted to the turbine via the elastic member and the driven member.

In this lock-up device, the drive member has a pair of frictional connecting portions on the front cover side and the turbine side, and the elastic member is disposed between the pair of frictional connecting portions in the axial direction. The damper mechanism and the friction coupling part can all be arranged on the outer peripheral portion of the space between the front cover and the turbine. Thereby, the torsional vibration absorbing performance is improved and the torque transmission capacity is increased.

According to a second aspect of the present invention, in the lock-up device for a hydraulic torque transmission device according to the first aspect, the first frictional connection portion includes a first plate portion provided to face the front cover, and a first plate portion. A first friction plate having a lower rigidity than the first plate portion, the second friction coupling portion being provided on a side surface on the front cover side of the portion, the second friction connection portion being provided with a second plate portion facing the piston; A second friction plate provided on a side surface of the plate portion on the piston side and having lower rigidity than the second plate portion.

In this lock-up device, the first friction plate installed on the drive member is connected to the first friction plate of the drive member.
Since the rigidity is lower than that of the plate portion, it is possible to reduce the engagement shock when the front cover is pressed against the friction surface as compared with a case where the friction facing is directly attached to the first frictional connection portion. In addition, the ability to follow the friction surface is further improved. Similarly, since the second friction plate has lower rigidity than the second plate portion, it is possible to reduce the engagement shock at the time of pressing the piston, and the followability to the piston is further improved.

According to a third aspect of the present invention, there is provided a lock-up device for a hydraulic torque transmission device according to the first or second aspect, wherein the piston is arranged so as to axially divide a space between the front cover and the turbine. A check valve mechanism that allows oil to flow from the space on the front cover side of the piston to the space on the turbine side but prohibits oil from flowing in the opposite direction is further provided.

Since this lock-up device has a check valve mechanism, at the time of lock-up, there is no flow of hydraulic oil from the space on the turbine side to the space on the front cover side, thereby improving the responsiveness of the lock-up device. It is possible to Also, at the time of lock-up release, the flow of hydraulic oil from the space on the front cover side to the space on the turbine side can be ensured.

According to a fourth aspect of the present invention, in the lock-up device for a hydraulic torque transmission device,
A disk-shaped member having a center hole formed therein, the inner peripheral edge and the outer peripheral edge being movable in the axial direction in a sealed state, and the check valve mechanism includes a hole formed in the piston and a hole formed in the turbine. And a valve member that closes openably from the side.

In this lockup device, the piston is
Since the inner peripheral edge and the outer peripheral edge are both sealed, the hydraulic oil between the space on the front cover side of the piston and the space on the turbine side flows only through the check valve mechanism. Since the check valve mechanism is formed on the piston, the pressure receiving area of the piston is not reduced.

According to a fifth aspect of the present invention, there is provided a lock-up device for a hydraulic torque transmitting device, comprising: a front cover having a friction surface; an impeller fixed to the front cover to form a fluid chamber filled with hydraulic oil; A lock-up device provided in a fluid torque transmission device including a turbine disposed to face an impeller, the drive member having a frictional connection portion disposed to face a friction surface, and a drive member fixed to the turbine. The driven member, a plurality of elastic members for elastically connecting the drive member and the driven member in the rotational direction, and axially divide the space between the front cover and the turbine on the turbine side of the drive member. The piston for pressing the friction coupling portion against the friction surface, which is provided so as to rotate integrally with the front cover, and hydraulic oil, Allowing the flow from the space of the front cover side of the piston to the turbine side of the space, but a non-return valve mechanism to prohibit the flow in opposite direction.

In this lock-up device, the frictional connection portion formed on the drive member is pressed by the piston and pressed against the friction surface of the front cover. As a result, the torque input to the front cover is transmitted from the friction surface of the front cover to the drive member via the friction connecting portion, and further transmitted to the turbine via the elastic member and the driven member.

Since this lock-up device has a check valve mechanism, at the time of lock-up, there is no flow of hydraulic oil from the space on the turbine side to the space on the front cover side, thereby improving the responsiveness of the lock-up device. It is possible to Also, at the time of lock-up release, the flow of hydraulic oil from the space on the front cover side to the space on the turbine side can be ensured.

According to a sixth aspect of the present invention, in the lock-up device for a hydraulic torque transmitting device,
A disk-shaped member having a center hole formed therein, the inner peripheral edge and the outer peripheral edge being movable in the axial direction in a sealed state, and the check valve mechanism includes a hole formed in the piston and a hole formed in the turbine. And a valve member that opens and closes freely from the side space.

In this lockup device, the piston is
Since both the inner peripheral edge and the outer peripheral edge are sealed, hydraulic oil between the space on the front cover side of the piston and the space on the turbine side is supplied only through the check valve mechanism. Since the check valve mechanism is formed on the piston, the pressure receiving area of the piston is not reduced.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. (1) Basic Structure of Torque Converter FIG. 1 is a schematic longitudinal sectional view of a torque converter 1 in which one embodiment of the present invention is adopted. The torque converter 1 is a device for transmitting torque from a crankshaft 2 of an engine to an input shaft 3 of a transmission.
An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of FIG.
OO shown in FIG. 1 is a rotation shaft of the torque converter 1.

The torque converter 1 mainly comprises a flexible plate 4 and a torque converter body 5. The flexible plate 4 is a thin disk-shaped member that transmits torque and absorbs bending vibration transmitted from the crankshaft 2 to the torque converter body 5. Therefore, the flexible plate 4 has sufficient rigidity for transmitting torque in the rotation direction, but has low rigidity in the bending direction.

The torque converter body 5 includes a front cover 11 to which the outer peripheral side of the flexible plate 4 is fixed.
And a torus-shaped fluid working chamber 6 composed of three types of impellers (the impeller 21, the turbine 22, and the stator 23).
And a lock-up device 7.

The front cover 11 is a disk-shaped member, and a boss member 16 which is a cylindrical member extending in the axial direction is fixed to the inner peripheral end. The boss member 16 is inserted into a center hole of the crankshaft 2.

An outer peripheral cylindrical portion 11a extending toward the transmission is formed on the outer peripheral portion of the front cover 11. An impeller 2 is attached to the tip of the outer cylindrical portion 11a.
The outer peripheral edge of one impeller shell 26 is fixed by welding together with a piston support 76 described later in detail. As a result, the front cover 11 and the impeller 21
Thus, the fluid working chamber 6 filled with the working oil is formed.

The impeller 21 mainly includes an impeller shell 26, a plurality of impeller blades 27 fixed inside the impeller shell 26, and an impeller hub 28 fixed to an inner peripheral portion of the impeller shell 26.

The turbine 22 is disposed in the fluid working chamber 6 so as to face the impeller 21 in the axial direction. Turbine 2
2 mainly includes a turbine shell 30, a plurality of turbine blades 31 fixed to a surface on the impeller side thereof, and a turbine hub 32 fixed to an inner peripheral edge of the turbine shell 30.
It is composed of The turbine hub 32 includes a flange portion 32a and a boss portion 32b. The turbine shell 30 and the turbine hub 32 are connected to each other by a plurality of rivets 33 together with a driven plate 62 described later in detail in the flange portion 32a of the turbine hub 32. Fixed.

A spline engaging with the input shaft 3 is formed on the inner peripheral surface of the boss 32b of the turbine hub 32. Thereby, the turbine hub 32 rotates integrally with the input shaft 3.

The stator 23 is provided between the inner peripheral portion of the impeller 21 and the inner peripheral portion of the turbine 22, and is a mechanism for rectifying the flow of hydraulic oil returning from the turbine 22 to the impeller 21. The stator 23 is a member integrally manufactured by resin molding or casting of an aluminum alloy. The stator 23 mainly includes an annular stator carrier 35 and a plurality of stator blades 36 provided on an outer peripheral surface of the stator carrier 35.
It is composed of The stator carrier 35 is supported on a cylindrical fixed shaft 39 via a one-way clutch 37. The fixed shaft 39 extends between the outer peripheral surface of the input shaft 3 and the inner peripheral surface of the impeller hub 28.

An annular space 9 is provided between the front cover 11 and the turbine 22 in the fluid chamber. A first thrust bearing 41 is arranged between the front cover 11 and the turbine hub 32 in the axial direction. In the portion where the first thrust bearing 41 is arranged, a first port 17 through which hydraulic oil can communicate is formed. That is, the first port 17 is connected to an oil passage between the center hole 3a of the input shaft 3 and the turbine hub 32,
The outer peripheral side of the boss portion 32b of the turbine hub 32, that is, the space 9 is communicated. Further, the inner peripheral portions of the turbine hub 32 and the stator 23 (specifically, the one-way clutch 3
7), a second thrust bearing 42 is arranged. In a portion where the second thrust bearing 42 is disposed, a second port 18 through which hydraulic oil can be communicated is formed. That is, the second port 18 communicates the oil passage between the input shaft 3 and the fixed shaft 39 with the working fluid chamber 6. Further, a third thrust bearing 43 is arranged between the stator 23 (specifically, the stator carrier 35) and the impeller 21 (specifically, the impeller hub 28) in the axial direction. In a portion where the third thrust bearing is disposed, a third port 19 through which hydraulic oil can communicate is formed. That is, the third
The port 19 has a fixed shaft 39 and an impeller hub 28.
And the fluid working chamber 6 is communicated. Each oil passage is connected to a hydraulic circuit (not shown).
Independent supply of hydraulic oil to the first to third ports 17 to 19
Emissions are possible.

(2) Structure of Lock-Up Device The lock-up device 7 is disposed in the space 9 between the front cover 11 and the turbine 22, and is a mechanism for mechanically connecting the two as necessary. is there. The lock-up device 7 has functions of a clutch and an elastic coupling mechanism, and mainly includes a damper mechanism 60, a piston 74, and a piston coupling mechanism 75.

First, the damper mechanism 60 will be described with reference to FIGS. The damper mechanism 60 has a function of elastically connecting the front cover 11 and the turbine 22 to transmit torque, and mainly includes a first drive plate 61, a driven plate 62, and a second drive plate 63. , A torsion spring 64 and a stud pin 65.

The first drive plate 61 is an annular plate member arranged on the outer peripheral side of the front cover 11, and inputs a torque from the front cover 11 to the torsion spring 64 integrally with the second drive plate 63. Has a function. First drive plate 61
Is mainly composed of a first plate portion 61a arranged to face the friction surface 11b of the front cover 11, and a cylindrical portion 61b extending from the outer peripheral edge toward the transmission.

A first friction plate 66 for pressing and frictionally engaging the friction surface 11b of the front cover 11 is disposed on the engine side surface of the first plate portion 61a. , A first friction facing 66a is attached. Further, the first friction plate 66 has a smaller thickness and a lower rigidity than the first plate portion 61a. Further, a plurality of first fixing holes 66b through which the stud pins 65 pass are formed at equal intervals along the circumference on the inner peripheral side of the first friction facing 66a of the first friction plate 66. 1
A plurality of second fixing holes 61d through which the stud pins 65 pass are formed at equal intervals along the circumference also on the inner peripheral side of the plate portion 61a.

The first plate portion 61a and the first
A first friction coupling portion is formed by the friction plate 66 and the first friction facing 66a. Note that the first friction facing 66a may be directly fixed to the first plate portion 61a.

The cylindrical portion 61b extends straight toward the transmission, and a plurality of fixed claw portions 61c bent inwardly are formed at the front end thereof at equal intervals along the circumference.

The second drive plate 63 is an annular plate member arranged on the transmission side of the first drive plate 61, and integrally with the first drive plate 61, applies the torque input from the front cover 11 to the torsion spring. It has a function of transmitting to the driven plate 62 via the second plate 64. The second drive plate 63 is mainly opposed to the first plate portion 61a of the first drive plate 61 with an interval in the axial direction, and is disposed close to a pressing portion 74a (described later) of the piston 74. It comprises a second plate portion 63a and a cylindrical portion 63b extending from the outer peripheral edge toward the engine. The cylindrical portion 63b extends substantially straight in the axial direction, but has a shape in which the tip is bent inward.

The second plate portion 63a is formed with a plurality of first cut and raised portions 63c and second cut and raised portions 63d cut and raised in the axial direction. First cut and raised section 6
3c is formed along the circumference and is arranged on the inner peripheral side of the cylindrical portion 63b with a gap. Second cut-and-raised part 63
d is arranged between the first cut-and-raised portions 63c in the rotational direction, and is located on the outer peripheral side of the radial position of the first cut-and-raised portions 63c. Further, a plurality of recesses 63g corresponding to the fixing claws 61c of the first drive plate 61 are formed on the outer peripheral edge of the transmission side surface of the second plate portion 63a.

The cylindrical portion 61b of the first drive plate 61 is connected to the cylindrical portion 63b of the second drive plate 63.
Of the first drive plate 61, and the fixed claw 61 c of the first drive plate 61 is locked by the recess 63 g of the second drive plate 63. The tip of the cylindrical portion 63b of the second drive plate 63 is
It is in contact with the transmission side surface of the plate portion 61a.

A second friction plate 67 is provided on the transmission side surface of the second plate portion 63a so that the pressing portion 74a of the piston 74 is brought into pressure contact with and frictionally engaged with the transmission portion of the second friction plate 67. Has a second friction facing 67a attached thereto.
Further, the second friction plate 67 includes a second plate portion 63a.
The plate thickness is smaller and the rigidity is weaker. further,
A plurality of third fixing holes 63f through which the stud pins 65 pass are formed at equal intervals along the circumference on the inner peripheral side of the first cut-and-raised portion 63c of the second plate portion 63a.
The fourth fixing hole 67 through which the stud pin 65 penetrates also on the inner peripheral side of the second friction facing 67 a of the second friction plate 67.
b are formed at equal intervals along the circumference.

The second plate portion 63a and the second
A second friction connecting portion is formed by the friction plate 67 and the second friction facing 67a. Note that the second friction facing 67a may be directly fixed to the second plate portion 63a.

The cylindrical portion 63b has a second plate portion 63a
Is formed at a position corresponding to the second cut-and-raised portion 63d.

In this embodiment, the torsion spring 64 is a plurality (six) of coil springs extending in the circumferential direction, and has a cylindrical portion 63 b of the second drive plate 63 and a second drive plate 63 on both sides in the radial direction. And the first cut-and-raised portion 63c formed at
Further, the end in the rotation direction is supported directly or through a spring seat in contact with or close to the second cut-and-raised portion 63d as the torque transmitting portion and the projected portion 63e. Further, the transmission side surface is supported by the second plate portion 63a, and the engine side surface is supported by the bent portion at the tip of the cylindrical portion 63b so that each torsion spring 64 does not fall off the second drive plate 63.

The driven plate 62 is an annular plate member disposed between the first drive plate 61 and the second drive plate 63 in the axial direction, and is input to the first drive plate 61 and the second drive plate 63. It has a function of transmitting torque from the torsion spring 64 to the turbine. The driven plate 62 mainly includes a disc-shaped portion 62a and a plurality of holding claws 62b formed on an outer peripheral edge thereof.

A connecting hole 62 is formed on the inner peripheral side of the disc-shaped portion 62a.
c are formed along the circumference.
The rivet 33 penetrating the turbine hub 32
A driven plate 62 is fixed to the side of the engine of the flange portion 32a. A stud pin 65 is provided between the outer peripheral edge of the disc-shaped portion 62a and the connection hole 62c in the radial direction.
Are formed at equal intervals along the circumference. Further, a driven plate 6 is provided between the long hole 62d of the disc-shaped portion 62a and the connection hole 62c in the radial direction.
A plurality of oil holes 62e for communicating the space on the engine side with the space on the transmission side are formed.
Further, the portion from the long hole 62d to the outer peripheral edge of the disc-shaped portion 62a and the holding claw portion 62b are
And the second drive plate 63 in the axial direction.

As shown in FIGS. 3 and 6, the holding claw portion 62b has a plurality of first portions 62f extending further from the outer peripheral edge of the disc-shaped portion 62a to the outer peripheral side, and a second portion extending therefrom toward the transmission. 62g. Note that both sides in the rotational direction of the boundary between the first portion 62f and the second portion 62g are slightly cut and raised toward the outer periphery. Therefore, the second portion 62g has a rotating end surface that extends straight. The end face in the rotation direction of the second portion 62g is in contact with two portions of the torsion spring 64 which are opposed to each other in the coil radial direction. With the structure in which the root of the second portion 62g of the holding claw portion 62b is cut and raised, the setting of the contact surface between the holding claw portion 62b and the torsion spring 64 can be easily optimized.

The stud pins 65 are used to fix the first friction plate 66, the first drive plate 61, the second drive plate 63, and the second friction plate 67, which are arranged in this order from the engine side, into respective fixing holes, that is, the first fixing plate. Hole 6
6b, a pin member for penetrating and fixing the second fixing hole 61d, the third fixing hole 63f, and the fourth fixing hole 67b. The stud pin 65 has a first head 65 having a diameter larger than that of the first fixing hole 66b abutting on the engine side of the first friction plate 66.
a, a first body 65b having a diameter penetrating the first fixing hole 66b and the second fixing hole 61d is formed on the transmission side of the first head 65a. First trunk 6
5b, the driven plate 6
A second body portion 65c having a diameter larger than the diameter of the first body portion 65b is formed through the second long hole 62d, and the driven plate 62 rotates relative to the second drive plate 63 in the long hole 62d. I can do it. On the transmission side of the second body 65c, a third body 65d having a diameter penetrating the third fixing hole 63f and the fourth fixing hole 67b is formed. A second head 6 having a larger diameter than the fourth fixing hole 67b is provided on the transmission side of the third body 65d.
5e is formed, and abuts on the transmission side of the second friction plate 67 to fix these plate members.

As described above, the inner peripheral portions of the first drive plate 61 and the second drive plate 63 are fixed by the stud pins 65. Further, the outer peripheral portions of the first drive plate 61 and the second drive plate 63 are engaged with each other as described above. Thus, the first drive plate 61 and the second drive plate 63 are fixed in the axial direction and the rotational direction, and constitute an integral drive member.

The axial distance between the inner periphery of the first drive plate 61 and the inner periphery of the second drive plate 63 is larger than the axial length of the second body 65c of the stud pin 65. The drive member is axially movable with respect to the driven plate 62 within a predetermined axial distance.

The third body 65c of the stud pin 65
, A wave spring 68 is interposed between the driven plate 62 and the second drive plate 63 in the axial direction.

The wave spring 68 is a member for urging the drive member from the driven plate 62 toward the transmission when the clutch is engaged. Therefore, when the clutch is released, as shown in FIG.
The drive member is located closest to the transmission with respect to the driven plate 62. More specifically, the inner peripheral portion of the first drive plate 61 is
2, and the first friction plate 66 is apart from the friction surface 11 b of the front cover 11.

In the structure of the damper mechanism 60 described above, the two friction coupling portions are arranged with an interval in the axial direction, and the torsion spring 64 is arranged between them.
The torsion spring 64 and the two friction coupling portions can be arranged on the outermost side in the space between the front cover 11 and the turbine 22. As a result, while maintaining the torsional vibration absorbing performance of the torsion spring 64, the torque transmission capacity can be increased by arranging the two friction coupling portions on the outer peripheral side of the conventional structure. In the present embodiment, the two friction coupling portions and the torsion spring have substantially the same radial center position and radial width, and are completely overlapped in the axial direction. It may have a width. However, it is necessary that at least a part of the torsion spring is axially overlapped with the friction connecting portion.

Next, the piston 74 and the piston connecting mechanism 75 shown in FIGS. 2, 3 and 7 will be described.
The piston 74 is a disc-shaped member having a center hole formed therein, and has a function of engaging and disengaging the clutch. The piston 74 is disposed between the damper mechanism 60 and the turbine 22, and has an outer peripheral edge formed on the outer cylindrical portion 11 of the front cover 11.
a, and the inner peripheral edge is close to the outer peripheral surface of the turbine hub 32. That is, the piston 74 divides the space 9 between the front cover 11 and the turbine 22 into the first space 9a on the front cover 11 side and the second space 9 on the turbine side.
b.

The piston 74 mainly includes a pressing portion 74a,
First cylindrical portion 74 formed on the inner peripheral edge and extending to the engine side
b, a second cylindrical portion 74c formed on the outer peripheral edge and extending toward the transmission, a pressing portion 74a, and a first cylindrical portion 74.
b.

The pressing portion 74a is a flat annular portion, and the second friction facing 67a of the second drive plate 63
Is arranged facing the transmission side. The inner peripheral surface of the first cylindrical portion 74b is in contact with the outer peripheral surface of the flange portion 32a of the turbine hub 32, and is rotatably fitted to the turbine hub 32 via a seal member 81.
As a result, the inner peripheral portion of the piston 74 is
Both sides in the axial direction are sealed with the outer peripheral portion of the second flange portion 32a.

The outer peripheral surface of the second cylindrical portion 74c is in contact with the inner peripheral surface of the outer cylindrical portion 11a of the front cover 11, and the outer cylindrical portion 11a of the front cover 11 is interposed via the sealing member 78. Is fitted on the inner peripheral surface. Thereby, the outer peripheral portion of the piston 74 is sealed on both sides in the axial direction with the inner peripheral surface of the outer cylindrical portion 11 a of the front cover 11. Further, a folded portion 74 bent inwardly is provided on the transmission-side end of the second cylindrical portion 74c.
d is formed, and a plurality of slits 74e are further formed along the circumference of the folded portion 74d.

The communication hole 74f has a function of an oil passage between the first space 9a and the second space 9b to secure the flow of the hydraulic oil. When the oil pressure in the first space 9a is relatively higher than the oil pressure in the second space 9b, the operating oil flows on the transmission side surface of each communication hole 74f, but the oil pressure in the second space 9b is lower than the first space. If the oil pressure is relatively higher than 9a, a check valve 79 that does not allow hydraulic oil to flow is provided. In the present embodiment, the type of the check valve 79 includes:
The flapper type is used.

In the structure of the piston 74 described above, since the outer peripheral end of the piston 74 extends to the inner peripheral portion of the outer cylindrical portion 11a of the front cover 11, the pressure receiving area of the piston 74 is increased. Further, since the check valve 79 is provided on the transmission side surface of the piston 74, the pressure receiving area of the piston 74 is not reduced.

The piston connecting mechanism 75 is disposed on the outer cylindrical portion 11a of the front cover 11, and integrally moves the piston 74 with respect to the front cover 11 so as to be immovable in the rotational direction and movable in the axial direction. It has a function of connecting so as to rotate. The piston coupling mechanism 75 includes a slit portion 74e formed in the folded portion 74d of the piston 74, an engagement claw portion 76a formed at the engine-side end of the piston support 76, and an engine formed by the second cylindrical portion 74c of the piston 74 And a cone spring 77 installed in a concave portion 11c on the inner peripheral surface of the outer cylindrical portion 11a of the front cover 11 on the side.

The engaging claw 76a of the piston support 76
Is the slit portion 74 of the folded portion 74d of the piston 74.
e, the piston is engaged with the front cover 11 so as to be immovable in the rotational direction and movably in the axial direction with respect to the front cover 11.

The cone spring 77 abuts on the engine side surface of the second cylindrical portion 74c of the piston 74, and urges the piston 74 in a direction away from the second friction facing 67a of the second drive plate 63.

In the structure of the piston connecting mechanism 75 described above, since the members constituting the piston connecting mechanism 75 are arranged on the outer peripheral portion of the space between the front cover 11 and the turbine 22, the space property is improved. ing.

Since the lock-up device 7 is constituted by the damper mechanism 60, the piston 74 and the piston connecting mechanism 75 described above, the front cover 11
The axial dimension of the inner peripheral portion of the torque converter is as short as the torque converter having no lock-up device. Thereby, the space in the axial direction near the crankshaft is improved.

(3) Operation of Torque Converter and Lockup Device The operation of the torque converter 1 and the lockup device 7 will be described below with reference to FIGS.

Immediately after the engine is started, hydraulic oil is supplied into the torque converter main body 5 from the first port 17 and the third port 19, and hydraulic oil is discharged from the second port 18. The hydraulic oil supplied from the first port 17 is supplied to the outer peripheral side of the damper mechanism 60 and the oil hole 62 e of the driven plate 62.
Flows through. At this time, since the oil pressure in the first space 9a is higher than the oil pressure in the second space 9b, the check valve 79 is opened, and the hydraulic oil flows from the first space 9a through the communication hole 74f of the piston 74 to the second space 9a. 9b, and finally into the fluid working chamber 6.

At this time, the piston 74 moves toward the transmission side by the urging force of the cone spring 77 of the piston connecting mechanism 75,
d stops in a state where d comes into contact with the base of the engagement claw portion 76a of the piston support 76. The drive member moves toward the transmission side by the urging force of the wave spring 68, and stops in a state where the first drive plate 61 is in contact with the driven plate 62. Therefore, the pressing portion 74a of the piston 74 is separated from the second friction plate 67 of the second drive plate 63, and the first friction plate 66 of the first drive plate 61 is separated from the friction surface 11b of the front cover 11. That is, the lock-up device 7 is disconnected and does not transmit torque.

When the lock-up is released, the torque transmission between the front cover 11 and the turbine 22 is performed by the fluid drive between the impeller 21 and the turbine 22.

When the speed ratio of the torque converter 1 increases and the input shaft 3 reaches a certain rotation speed, the first port 1
Hydraulic oil in the first space 9a is discharged from 7. On this occasion,
Since the oil pressure in the first space 9a decreases and the oil pressure in the second space 9b relatively increases, the check valve 79 closes. Thereby, the piston 74 is promptly moved to the front cover 11 side, and the pressing portion 74a is moved to the second drive plate 6.
The third friction plate 67 of the third drive plate 61 is pressed, and the first friction plate 66 of the first drive plate 61 is further pressed against the friction surface 11 b of the front cover 11. As a result, the torque of the front cover 11 is transmitted from the first drive plate 61 and the second drive plate 63 to the driven plate 62 via the torsion spring 64. Further, the torque is transmitted from the driven plate 62 to the turbine 22. Further, the front cover 11 is mechanically connected to the turbine 22, and the torque of the front cover 11 is directly output to the input shaft 3 via the turbine 22.

At this time, the first friction plate 66 and the second
Since the friction plates 67 are smaller in thickness than the first drive plate 61 and the second drive plate 63 and have low rigidity, the engagement shock at the time of pressing is reduced, and the followability to each friction surface is further improved. Has improved.

Since the check valve 79 is closed and there is no leakage of hydraulic oil from the second space 9b to the first space 9a,
The movement of the piston 74 toward the engine is quickly performed. That is, the responsiveness of the lock-up operation is improved.

The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration is not limited to this embodiment, and can be changed without departing from the gist of the invention.

For example, in this embodiment, a flapper type check valve mechanism is used as the check valve mechanism, but a spring type check valve mechanism may be used.

[0079]

In the lock-up device according to the present invention, the elastic member is disposed axially between the pair of friction coupling portions by the drive member having the pair of friction coupling portions on the front cover side and the turbine side. Therefore, all of these members can be arranged on the outer peripheral portion of the space between the front cover and the turbine. Thereby, it is possible to improve the torsional vibration absorbing performance and increase the torque transmission capacity.

Further, by providing a check valve on the piston, it is possible to improve the responsiveness of the lock-up operation.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged view of FIG. 1, showing a lock-up device.

FIG. 3 is a partially enlarged view of FIG. 2, showing a damper mechanism and a piston connection mechanism.

FIG. 4 is an exploded perspective view of a first friction plate and a first drive plate of the damper mechanism.

FIG. 5 is an exploded perspective view of a driven plate, a stud pin, a wave spring, a second drive plate, and a second friction plate of the damper mechanism.

FIG. 6 is a partial perspective view of a holding claw portion of the driven plate.

FIG. 7 is an exploded perspective view of a piston and a piston coupling mechanism.

[Explanation of symbols]

 7 Lock-up device 11 Front cover 60 Damper mechanism 61 First drive plate 62 Driven plate 63 Second drive plate 64 Torsion spring 65 Stud pin 74 Piston 75 Piston coupling mechanism 79 Check valve

Claims (6)

[Claims] A front cover having a friction surface; an impeller fixed to the front cover to form a fluid chamber filled with hydraulic oil; and a turbine disposed in the fluid chamber so as to face the impeller. A lock-up device provided in the hydraulic torque transmission device, wherein a first frictional connection portion disposed on an outer peripheral portion of a space between the front cover and the turbine so as to face the frictional surface, and A drive member having a second frictional connection part disposed at a position away from the first frictional connection part on the turbine side; and a drive member fixed to the turbine and at least a part of which is the first frictional connection part and the second frictional connection part. A driven member extending between the first frictional connection portion and the second frictional connection portion for elastically connecting the drive member and the driven member in a rotational direction. And a plurality of elastic members for rotating the first frictional connection portion between the drive member and the turbine so as to rotate integrally with the front cover, and pressing the first frictional connection portion by pressing against the second frictional connection portion. A lock-up device for a hydraulic torque transmission device, comprising: a piston for pressing against a surface. 2. The first frictional connection portion includes a first plate portion provided to face the front cover, and a first plate portion provided on a side surface of the first plate portion on the front cover side. A first friction plate having low rigidity, wherein the second friction connection portion is provided on a side of the second plate portion facing the piston, the second plate portion being provided facing the piston; The lock-up device for a hydraulic torque transmission device according to claim 1, further comprising a second friction plate having a lower rigidity than the second plate portion. 3. The piston is arranged so as to divide a space between the front cover and the turbine in an axial direction, and hydraulic oil flows from a space of the piston on the front cover side to a space on the turbine side. Allow to flow,
The lock-up device for a hydraulic torque transmission device according to claim 1 or 2, further comprising a check valve mechanism for inhibiting flow in the reverse direction. 4. The piston is a disc-shaped member having a center hole formed therein, and the inner peripheral edge and the outer peripheral edge are movable in the axial direction in a sealed state. The lock-up device for a hydraulic torque transmission device according to claim 3, further comprising a hole formed in the piston, and a valve member that closes and opens the hole from the turbine side. 5. A front cover having a friction surface, an impeller fixed to the front cover to form a fluid chamber filled with hydraulic oil, and a turbine disposed in the fluid chamber so as to face the impeller. A drive member having a friction coupling portion disposed opposite to the friction surface, a driven member fixed to the turbine, and the drive member. A plurality of elastic members for elastically connecting the driven member in a rotational direction; and a plurality of elastic members arranged on the turbine side of the drive member so as to axially divide a space between the front cover and the turbine. A piston provided to rotate integrally with the front cover, and for pressing the friction coupling portion against the friction surface; But it is allowed to flow from the space of the front cover side of the piston to the turbine side of the space,
A lock-up device for a hydraulic torque transmission device, comprising: a check valve mechanism for inhibiting flow in the reverse direction. 6. The piston is a disk-shaped member having a center hole formed therein, and the inner peripheral edge and the outer peripheral edge are movable in the axial direction in a sealed state. The lock-up device for a hydraulic torque transmission device according to claim 5, further comprising a hole formed in the piston, and a valve member that opens and closes the hole from the space on the turbine side so as to be able to open and close.