WO2016103891A1

WO2016103891A1 - Lockup device for torque converter and method for controlling same

Info

Publication number: WO2016103891A1
Application number: PCT/JP2015/080072
Authority: WO
Inventors: 亮太中野; 佐藤　佳司
Original assignee: 株式会社エクセディ
Priority date: 2014-12-24
Filing date: 2015-10-26
Publication date: 2016-06-30

Abstract

The present invention pertains to a device which mechanically couples a front cover to an output side, thereby eliminating the need to supply hydraulic oil when in a locked state, wherein a shock occurring when transitioning from a locked state to an unlocked state is suppressed. This device is provided with a first clutch part (28), a piston (30), and a dog clutch (32). The first clutch part (28) allows torque to be transmitted between the front cover (2) and a turbine (4) when transitioning between the locked and unlocked states, and prevents torque from being transmitted while in the unlocked state or the locked state. The piston (30) transmits torque from the first clutch part (28) to the turbine (4). The dog clutch (32) has a coupling member (40) which couples the front cover (2) and the piston (30) while in the locked state and decouples the front cover (2) and the piston (30) while in the unlocked state.

Description

Torque converter lockup device and control method thereof

The present invention relates to a lockup device, and more particularly, to a torque converter lockup device disposed between a front cover and a turbine. The present invention also relates to a method for controlling the lockup device, and more particularly to a method for controlling the lockup device when releasing the lockup state from the lockup state.

The torque converter is a device that transmits torque from the engine to the transmission side via an internal working fluid, and mainly includes a front cover to which torque from the engine is input, an impeller, a turbine, and a stator. I have. Torque input to the front cover is transmitted from the impeller to the turbine via hydraulic oil and output to the transmission side. The hydraulic fluid returning from the turbine to the impeller is rectified by the stator.

Also, many torque converters are equipped with a lock-up device arranged between the front cover and the turbine. The lock-up device includes, for example, a piston that has a friction member and is pressed against the front cover, and a damper mechanism that is disposed between the piston and the turbine.

In the lockup device, it is necessary to maintain a predetermined hydraulic pressure with respect to the piston in the lockup state (torque transmission state by the lockup device). On the other hand, Patent Document 1 discloses a device that eliminates the need for hydraulic pressure to the piston in the lock-up state.

The device disclosed in Patent Document 1 includes a first clutch portion and a second clutch portion. The first clutch portion has a piston having a friction member. When the piston is slid in the axial direction by the hydraulic oil, the front cover and the turbine are switched between the torque transmission state and the torque transmission release state. On the other hand, the second clutch portion has a connecting member. The connecting member slides in the axial direction by the hydraulic oil, and can mechanically connect the front cover and the piston.

In this device, after the lockup state is once established by the first clutch portion, the front cover and the piston can be mechanically connected by the second clutch portion. For this reason, if the front cover and the piston are mechanically connected, it is not necessary to apply hydraulic pressure to the piston. For this reason, the loss by supply of hydraulic fluid can be suppressed.

JP 2013-256986 A

In the device of Patent Document 1, in the lock-up state, the torque is mechanically transmitted only by the second clutch portion. When the torque transmission state in the second clutch portion is released from such a state, the clutch does not slip as a transition state, and thus there is a possibility that a shock may occur when the torque transmission of the second clutch portion is released.

An object of the present invention is to shift from a lockup state to a lockup release state in a device in which the front cover and the output side are mechanically connected in the lockup state to eliminate the need for supplying hydraulic oil in the lockup state. It is to suppress the shock when doing.

(1) A lock-up device for a torque converter according to one aspect of the present invention is disposed between a front cover and a turbine, and includes a first clutch portion, a torque transmission member, and a second clutch portion. . The first clutch portion is actuated by hydraulic oil, and at the time of transition between the lock-up release state and the lock-up state, the first clutch portion is in a torque transmission state between the front cover and the turbine, and in the lock-up release state and the lock-up state, The torque transmission is released between the front cover and the turbine. A torque transmission member is arrange | positioned between a 1st clutch part and a turbine, and transmits the torque from a 1st clutch part to a turbine. The second clutch portion has a connecting member that can slide in the axial direction with hydraulic oil and mechanically connect the front cover and the torque transmitting member. When the connecting member is operated, the front cover and the torque transmission are transmitted in the locked-up state. The connection between the front cover and the torque transmitting member is set to a disconnected state in the lock-up released state.

In this device, torque is transmitted between the front cover and the turbine by operating the first clutch portion with hydraulic oil. Further, by operating the connecting member of the second clutch portion with the hydraulic oil, the connecting member mechanically connects the front cover and the torque transmitting member, and torque is transmitted between the front cover and the torque transmitting member. .

Here, the front cover → the torque transmission member → the turbine is mechanically connected to the second clutch portion while reducing the relative rotation between the front cover and the torque transmission member by setting the first clutch portion to the torque transmission state. Torque can be transmitted along the path. For this reason, if torque is transmitted between the front cover and the torque transmission member via the connecting member, it is not necessary to apply hydraulic oil to the first clutch portion and the second clutch portion.

Further, here, when shifting from the lock-up state to the lock-up release state, the first clutch portion is once brought into the torque transmission state, and then the connection of the second clutch portion is released. For this reason, it is possible to suppress a shock at the time of releasing the lock-up as compared with the case where the connection at the second clutch portion is released without once bringing the first clutch portion into the torque transmission state.

(2) The torque converter lock-up device according to another aspect of the present invention further includes a first hydraulic port and a second hydraulic port. The first hydraulic port supplies hydraulic oil for bringing the first clutch portion into a torque transmission state and operating the connecting member to bring the second clutch portion into a connected state. The second hydraulic port supplies hydraulic oil that brings the first clutch part into a torque transmission released state and operates the connecting member to bring the second clutch part into a released state.

Here, this device can be operated using a hydraulic circuit used in a torque converter having two hydraulic ports similar to the conventional device.

(3) In the torque converter lock-up device according to still another aspect of the present invention, the torque transmission member is a piston movable in the axial direction by hydraulic oil. The first clutch portion has a friction member fixed to the piston, and the friction member is pressed by the front cover to transmit torque between the front cover and the piston. The connecting member of the second clutch portion mechanically connects the front cover and the piston.

(4) In the torque converter lock-up device according to still another aspect of the present invention, the second clutch portion includes a first ring gear and a second ring gear. The first ring gear is provided on the front cover and has a plurality of teeth on the inner peripheral surface. The second ring gear is provided on the piston and has a plurality of teeth on the inner peripheral surface. The connecting member has a plurality of teeth on the outer peripheral surface that can mesh with the teeth of the first ring gear and the second ring gear.

Here, torque is transmitted through the connecting member between the front cover and the piston by the teeth formed on the outer peripheral surface of the connecting member meshing with the teeth of the first ring gear and the second ring gear.

(5) The torque converter lockup device according to still another aspect of the present invention further includes a first clutch portion, a second clutch portion, and an output member that outputs torque from the turbine. The output member has a disk-shaped flange and a cylindrical portion extending from the flange toward the axial front cover. The connecting member is supported on the outer peripheral surface of the cylindrical portion of the output member so as to be slidable in the axial direction.

(6) In the torque converter lockup device according to still another aspect of the present invention, an oil chamber is formed between the connecting member and the output member. This device is provided in the output member, and when the difference between the hydraulic oil pressure from the first hydraulic port and the hydraulic oil pressure from the second hydraulic port becomes a predetermined value or more, the oil chamber is connected to the first hydraulic port. A first valve for introducing the hydraulic oil.

Here, when hydraulic oil is supplied from the first hydraulic port, the first clutch unit is operated to enter a torque transmission state, and the rotational speed of the torque transmission member approaches the rotational speed of the front cover. Thereafter, hydraulic oil is supplied to the oil chamber via the first valve provided in the output member, and the connecting member is operated. By the operation of the connecting member, the front cover and the torque transmitting member are mechanically connected.

Here, the operation of the connecting member can be delayed from the operation start of the first clutch portion by the operation of the first valve. Therefore, the front cover and the torque transmission member are smoothly connected by the connecting member.

(7) In the torque converter lock-up device according to still another aspect of the present invention, when the hydraulic oil pressure provided from the first hydraulic port is equal to or lower than a predetermined value, provided in the output member, A second valve for discharging hydraulic oil is further provided.

Here, when the hydraulic oil pressure from the first hydraulic port falls below a predetermined value, the hydraulic oil that has been stored in the oil chamber until then is discharged through the second valve. For this reason, the connection between the front cover and the torque transmission member can be smoothly released by moving the connection member.

(8) In the lockup device for a torque converter according to still another aspect of the present invention, the connecting member includes an adjustment oil chamber whose internal volume can be changed, and a communication oil passage that connects the oil chamber and the adjustment oil chamber. ,have.

For example, if only one oil chamber is provided to operate the connecting member, once the working oil is supplied to the oil chamber, the connecting member is independently operated until the working oil in the oil chamber is discharged. It cannot be activated.

Thus, in this apparatus, the connecting oil is provided in the connecting member so that the operating oil can communicate between the oil chamber and the adjusting oil chamber, and the connecting member can be operated even when the operating oil is not discharged from the oil chamber. I am doing so. By adopting such a configuration, it is possible to release the connection of the second clutch portion by moving only the connecting member while maintaining the first clutch portion in the torque transmission state. That is, when the lockup is released, the second clutch portion can be released after the first clutch portion is in the torque transmission state, and then the first clutch portion can be in the torque transmission release state.

(9) A control method for a lockup device according to one aspect of the present invention is a lockup device having a first clutch portion, a torque transmission member, and a second clutch portion, and releases the lockup state from the lockup state. Control method. The first clutch portion is operated by hydraulic oil to perform torque transmission or torque transmission cancellation between the front cover and the turbine. The torque transmission member transmits torque from the first clutch portion to the turbine. The second clutch portion mechanically connects or disconnects the front cover and the torque transmission member by a connecting member that is operated by hydraulic oil. In the lock-up state, the second clutch portion is in a connected state and the first clutch portion is in a torque transmission release state.

The control method for the lockup device includes a first step, a second step, and a third step. A 1st step makes a 1st clutch part a torque transmission state in the state which maintained the 2nd clutch part in the connection state. In the second step, the connection of the second clutch portion is released while the torque transmission state of the first clutch portion is maintained. In the third step, after the connection of the second clutch portion is released, the first clutch portion is brought into a torque transmission release state.

(10) In the control method of the lockup device according to another aspect of the present invention, in the first step, the first hydraulic pressure is applied to the first clutch portion to set the torque transmission state. In the second step, in a state where the first hydraulic pressure is applied to the first clutch portion, a second hydraulic pressure lower than the first hydraulic pressure is applied to the second clutch portion to release the connection of the second clutch portion.

This makes it possible to release the connection at the second clutch part while maintaining the torque transmission state at the first clutch part.

In the present invention as described above, in a device in which the front cover and the output side are mechanically connected in the lock-up state to eliminate the need to supply hydraulic oil in the lock-up state, The shock when moving to can be suppressed.

1 is a cross-sectional view of a torque converter including a lockup device according to an embodiment of the present invention. The figure which extracts and shows the lockup apparatus of FIG. FIG. 2 is an enlarged partial view of FIG. 1 showing a positioning mechanism. The figure which extracts and shows the damper mechanism of FIG. The figure for demonstrating a hydraulic circuit. The cross-sectional block diagram which shows a main valve. The cross-sectional block diagram which shows an open valve. The flowchart for demonstrating the hydraulic control of a lockup apparatus.

FIG. 1 is a partial cross-sectional view of a torque converter 1 having a lock-up device as one embodiment of the present invention. An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of the figure. OO shown in FIG. 1 is the rotation axis of the torque converter and the lockup device.

[Overall configuration of torque converter]
The torque converter 1 is a device for transmitting torque from a crankshaft (not shown) on the engine side to an input shaft of a transmission. The torque converter 1 includes a front cover 2, a torque converter body 6 including three types of impellers (impeller 3, turbine 4, stator 5), and a lockup device 7.

The front cover 2 is fixed to a member on the engine side. The front cover 2 has a disk-shaped main body 2a and an outer peripheral cylindrical portion 2b that is formed on the outer peripheral portion and protrudes toward the axial transmission side.

The impeller 3 includes an impeller shell 12 fixed to the outer peripheral cylindrical portion 2 b of the front cover 2 by welding, a plurality of impeller blades 13 fixed to the inside thereof, and a cylindrical shape welded to the inner peripheral portion of the impeller shell 12. The impeller hub 14.

The turbine 4 is disposed opposite to the impeller 3 in the fluid chamber. The turbine 4 includes a turbine shell 15, a plurality of turbine blades 16 fixed to the turbine shell 15, and a turbine hub (an example of an output member) 17 fixed to the inner peripheral side of the turbine shell 15. .

The turbine hub 17 includes a flange 17a, a first cylindrical portion 17b, a second cylindrical portion 17c, and a third cylindrical portion 17d. The flange 17a is formed in a disk shape extending to the outer peripheral side. The inner peripheral portion of the turbine shell 15 is fixed to the flange 17 a by a plurality of rivets 18. The first cylindrical portion 17b is formed so as to protrude from the outer peripheral portion of the flange 17a to the front cover 2 side. The second cylindrical portion 17c and the third cylindrical portion 17d are formed on the inner peripheral portion of the flange 17a. The second cylindrical portion 17c is formed to protrude from the flange 17a to the front cover 2 side. The third cylindrical portion 17d is formed so as to protrude further toward the front cover 2 from the inner peripheral portion at the tip of the second cylindrical portion 17c. The third cylindrical portion 17d is smaller than the outer diameter of the second cylindrical portion 17c.

A spline hole is formed in the inner peripheral surface of the turbine hub 17. The transmission input shaft can be engaged with the spline hole.

The stator 5 is a mechanism for rectifying the hydraulic oil that is disposed between the impeller 3 and the inner peripheral portion of the turbine 4 and returns from the turbine 4 to the impeller 3. The stator 5 mainly includes an annular stator carrier 20 and a plurality of stator blades 21 provided on the outer peripheral surface thereof. The stator carrier 20 is supported by a fixed shaft (not shown) via a one-way clutch 22.

Thrust bearings

24 and 25 are provided between the turbine hub 17 and the one-way clutch 22 and between the one-way clutch 22 and the impeller shell 12, respectively.

[Lock-up device 7]
The lock-up device 7 is disposed in a space between the front cover 2 and the turbine 4, and transmits torque between them (hereinafter referred to as “lock-up state” or “lock-up on”) or cancels torque transmission. (Hereinafter referred to as “lock-up release” or “lock-up off”). The lock-up device 7 includes a friction member 28 (an example of a first clutch part), a piston 30 (an example of a torque transmission member), a dog clutch (an example of a second clutch part) 32, and a damper mechanism 34. Yes. Further, the lockup device 7 is provided with a hydraulic circuit.

<Friction member 28 and piston 30>
The friction member 28 is formed in an annular shape and is fixed to the outer peripheral side surface of the piston 30 on the front cover 2 side. The friction member 28 is for transmitting torque between the front cover 2, the damper mechanism 34, and the turbine 4 or releasing torque transmission by the piston 30 that moves in the axial direction by the hydraulic oil. Hereinafter, the friction member 28 is referred to as a “first clutch portion 28”.

As shown in FIG. 2, the piston 30 is a substantially disc-shaped member, and includes an outer peripheral disc portion 30a, an outer peripheral cylindrical portion 30b, an inner peripheral disc portion 30c, and an inner peripheral cylindrical portion 30d. ,have. The piston 30 is disposed between the front cover 2 and the damper mechanism 34, and is movable in the axial direction by hydraulic oil. 2 shows an extracted portion of the lock-up device 7 in FIG.

As described above, the annular friction member 28 is fixed to the outer peripheral portion of the outer peripheral disc portion 30a. The outer peripheral cylindrical portion 30b extends obliquely from the outer peripheral disc portion 30a toward the inner peripheral side, and further extends toward the axial turbine 4 side. The inner peripheral disc part 30c extends from the outer cylindrical part 30b to the inner peripheral side. The inner peripheral cylindrical portion 30d extends from the inner peripheral end of the inner peripheral disc portion 30c to the turbine 4 side. The inner peripheral cylindrical portion 30 d is slidably supported on the outer peripheral surface of the first cylindrical portion 17 b of the turbine hub 17. Further, a seal member 36 is disposed on the outer peripheral surface of the first cylindrical portion 17b of the turbine hub 17, so that the space between the inner peripheral surface of the piston 30 and the first cylindrical portion 17b of the turbine hub 17 is sealed. Has been.

<Dog clutch 32>
As shown in FIG. 2, the dog clutch 32 includes a connecting member 40 that is operated by hydraulic oil, a first ring gear 41, and a second ring gear 42. The dog clutch 32 is for mechanically connecting the front cover 2 and the piston 30 by the connecting member 40 and transmitting torque between the front cover 2 and the turbine 4 or releasing torque transmission.

The connecting member 40 is formed in an annular shape, and is disposed between the front cover 2 and the turbine hub 17 so as to be movable in the axial direction. An annular space is formed inside the connecting member 40. In the annular space, a bellows 44 in which helium gas is sealed is accommodated. The bellows 44 can expand and contract in the axial direction, and its volume changes when the pressure inside, that is, inside the annular space changes.

A plurality of teeth 40 a are formed on the outer peripheral surface of the connecting member 40. A chamfer is formed at the front end of each tooth 40a on the front cover side. The inner peripheral surface of the connecting member 40 is slidably supported on the outer peripheral surface of the third cylindrical portion 17d of the turbine hub 17 and the outer peripheral surface of a thrust washer 46 (described later). A seal member 47 is disposed on the outer peripheral surface of the third cylindrical portion 17d of the turbine hub, whereby the space between the inner peripheral surface of the connecting member 40 and the third cylindrical portion 17d is sealed.

Further, in the inner peripheral portion of the connecting member 40, an annular projecting portion 40b projecting to the turbine 4 side is formed on the side surface on the turbine 4 side. The annular projecting portion 40b is slidably supported on the outer peripheral surface of the second cylindrical portion 17c of the turbine hub 17. A seal member 48 is disposed on the inner peripheral surface of the annular projecting portion 40b, thereby sealing between the inner peripheral surface of the annular projecting portion 40b and the second cylindrical portion 17c.

The first ring gear 41 is fixed to the intermediate portion in the radial direction on the side surface of the front cover 2 on the turbine 4 side. A plurality of teeth 41 a are formed on the inner peripheral surface of the first ring gear 41. The second ring gear 42 is formed integrally with the piston 30 on the inner peripheral surface of the outer peripheral cylindrical portion 30 b of the piston 30. A plurality of teeth 42 a are formed on the inner peripheral surface of the second ring gear 42.

The teeth 40a of the connecting member 40 are always meshed with the teeth 42a of the second ring gear 42. Then, the connecting member 40 is moved to the front cover 2 side by the hydraulic oil, so that the teeth 40 a on the outer peripheral surface mesh with the teeth 41 a of the first ring gear 41. That is, the state in which the teeth 40a of the connecting member 40 mesh with the

teeth

41a, 42a of both the first ring gear 41 and the second ring gear 42 is the torque transmission state (clutch on) of the dog clutch 32, and the second ring A state where only the teeth 42a of the gear 42 are engaged is a torque transmission release state (clutch off) of the dog clutch 32.

<Positioning mechanism>
The lockup device 7 includes a positioning mechanism 49 for positioning the connecting member 40 in the axial direction. The positioning mechanism 49 has a thrust washer 46. As shown in FIG. 2, the thrust washer 46 is disposed on the inner peripheral side of the connecting member 40 between the third cylindrical portion 17 d of the turbine hub 17 and the front cover 2.

As shown in an enlarged view in FIG. 3, the thrust washer 46 is formed with two through holes 46a at positions opposed to each other in the radial direction (only one hole is shown in FIG. 3). A spring seat 50 is disposed in each of the two holes 46a. The spring seat 50 includes a disc-shaped collar portion 50a and a positioning projection 50b that projects from the center of the collar portion 50a. The positioning protrusion 50 b is inserted into the hole 46 a from the inner peripheral side of the thrust washer 46. A spring 51 is provided between the flange portions 50a of the two spring seats 50 so as to bias the two spring seats 50 outward.

On the other hand, two

annular recesses

40c and 40d are formed on the inner peripheral surface of the connecting member 40 in the axial direction. The tips of the positioning protrusions 50b of the two spring seats 50 can be fitted into the

annular recesses

40c and 40d.

With such a configuration, when the connecting member 40 moves to the front cover 2 side and the dog clutch 32 is in a torque transmission state (clutch on), the positioning protrusion 50b is fitted into one annular recess 40c of the connecting member 40, and the connecting member 40 is connected. The movement of the member 40 in the axial direction is restricted. Further, when the connecting member 40 moves to the turbine 4 side and the dog clutch 32 is in the torque transmission released state (clutch off), the positioning protrusion 50b is fitted in the other annular recess 40d of the connecting member 40, and the shaft of the connecting member 40 is Directional movement is restricted.

<Damper mechanism 34>
The damper mechanism 34 is disposed between the piston 30 and the turbine 4. As shown in FIG. 4, the damper mechanism 34 includes an input plate 54, a plurality of torsion springs 55, a float member 56, and an output plate 57.

The input plate 54 is an annular member, and the inner periphery is fixed to the piston 30 by a rivet 58. The input plate 54 includes a support portion 54a, a plurality of engagement portions 54b, and a plurality of stopper claws 54c. The support portion 54a is formed by bending the radial intermediate portion of the input plate 54 toward the turbine 4 and is formed in a cylindrical shape. The plurality of engaging portions 54b are formed by bending a part of the support portion 54a to the outer peripheral side and further bending the tip thereof to the turbine 4 side. The engaging portion 54 b is in contact with the circumferential end surface of the torsion spring 55. The stopper claw 54c is formed by extending a part of the support portion 54a further to the turbine 4 side.

The plurality of torsion springs 55 are arranged at intervals in the circumferential direction, and movement is regulated by the float member 56.

The float member 56 is formed in an annular shape, and includes a side portion 56a, an outer peripheral portion 56b, and an intermediate engagement portion 56c.

The side portion 56a is disposed between the piston 30 and the torsion spring 55, and restricts the movement of the torsion spring 55 toward the front cover 2 side. The inner peripheral surface of the side portion 56a is supported by the outer peripheral surface of the support portion 54a of the input plate 54, whereby the float member 56 is positioned in the radial direction.

The outer peripheral portion 56b is formed by extending the outer peripheral end of the side portion 56a toward the turbine 4 side. The outer peripheral portion 56b restricts the torsion spring 55 from projecting to the outer peripheral side. The movement of the torsion spring 55 toward the inner peripheral side is restricted by the stopper claw 54 c of the input plate 54.

The intermediate engaging part 56c is formed by cutting and raising a part of the side part 56a toward the turbine 4, and a part formed by bending a part of the outer peripheral part 56b toward the inner peripheral side and the front cover 2 side. ,have. The intermediate engagement portion 56 c can contact the end surface of the torsion spring 55. Further, the movement of the torsion spring 55 toward the turbine 4 side is restricted by an intermediate engagement portion 56c formed by bending a part of the outer peripheral portion 56b toward the inner peripheral side.

In the configuration as described above, the engaging portions 54b of the input plate 54 are engaged with both end faces in the circumferential direction of the set of two torsion springs 55 out of the plurality of torsion springs 55, and one set of two torsion springs. An intermediate engagement portion 56 c is inserted between the springs 55 and is in contact with the end surface of the torsion spring 55. Thereby, one set of two torsion springs 55 acts in series.

The output plate 57 is a substantially disk-shaped member, and an inner peripheral portion thereof is fixed to the flange 17 a of the turbine hub 17 together with the turbine shell 15 by a rivet 18. A cylindrical portion 57 a and a plurality of engaging portions 57 b are formed on the outer peripheral portion of the output plate 57. The cylindrical part 57a is formed by bending the outer peripheral part to the front cover 2 side. The plurality of engaging portions 57b are formed by bending a part of the tip of the cylindrical portion 57a to the outer peripheral side and the front cover 2 side.

The cylindrical portion 57a is formed with a notch extending in the circumferential direction at a portion where the plurality of engaging portions 57b are not formed. The stopper claw 54c of the input plate 54 is inserted into this notch. Therefore, the input plate 54 and the output plate 57 can rotate relative to each other as long as the stopper claw 54c can move within the notch.

The plurality of engaging portions 57 b can be engaged with both circumferential end surfaces of one set of two torsion springs 55 of the plurality of torsion springs 55.

<Hydraulic circuit>
The hydraulic circuit will be described with reference to FIG. The hydraulic circuit includes a first hydraulic port P1, a second hydraulic port P2, a first oil chamber Q1, a second oil chamber Q2, a third oil chamber Q3, a dog oil chamber Qd including a regulating oil chamber R, It has a main valve (an example of a first valve) Vc and an open valve (an example of a second valve) Vo (see FIG. 7).

The first hydraulic port P1 is formed between the turbine hub 17 and the one-way clutch 22. The first hydraulic port P1 supplies hydraulic oil into the torque converter body 6 and supplies hydraulic oil to the first oil chamber Q1. When the first hydraulic port P1 is connected to the drain, the hydraulic oil in the first oil chamber Q1 is discharged through the first hydraulic port P1. The second hydraulic port P2 is formed by a notch 46b formed at the end of the thrust washer 46 on the front cover 2 side. The second hydraulic port P2 supplies hydraulic oil to the second oil chamber Q2. Further, when the second hydraulic port P2 is connected to the drain, the hydraulic oil in the second oil chamber Q2 is discharged through the second hydraulic port P2.

The first oil chamber Q1 is a space formed on the turbine 4 side of the piston 30. The second oil chamber Q <b> 2 is a space formed between the front cover 2, the piston 30 and the connecting member 40. The piston 30 moves to the front cover 2 side by increasing the hydraulic pressure of the hydraulic oil in the first oil chamber Q1 (hereinafter simply referred to as “hydraulic pressure”) above the hydraulic pressure of the second oil chamber Q2.

The dog oil chamber Qd includes a third oil chamber Q3 and a regulating oil chamber R. The third oil chamber Q3 is a space formed between the inner peripheral portion of the connecting member 40 and the turbine hub 17. The adjustment oil chamber R is a space other than the space closed by the bellows 44 in the annular space formed inside the connecting member 40. Since the bellows 44 expands and contracts, the volume of the adjusting oil chamber R changes as the bellows 44 expands and contracts. The third oil chamber Q3 and the adjustment oil chamber R communicate with each other through a connection hole 40e formed in the connection member 40.

The main valve Vc is disposed inside the second cylindrical portion 17c of the turbine hub 17, as shown in FIG. 6 which is a partially enlarged view of FIGS. More specifically, a stepped hole penetrating in the axial direction is formed in the second cylindrical portion 17c, and the main valve Vc is disposed in this hole. The main valve Vc opens when the differential pressure between the first oil chamber Q1 and the third oil chamber Q3 (dog oil chamber Qd) exceeds a predetermined value, and is moved from the first hydraulic port P1 to the third oil chamber Q3 side. Guide hydraulic fluid. The main valve Vc has a spool 61 that can move in the axial direction, a seat 62, and a spring 63.

The spool 61 has a body portion 61a and a seal portion 61b. A horizontal hole 61c and a vertical hole 61d are formed in the body portion 61a. The lateral hole 61c extends in the axial direction at the center of the body 61a. The end of the horizontal hole 61c on the third oil chamber Q3 side is open, and the other end is closed. The vertical hole 61d is formed in the end portion of the body portion 61a on the seal portion 61b side so as to penetrate in the radial direction. The seal portion 61b is formed in a truncated cone shape, and an annular groove 61e is formed in a part thereof, and an O-ring 64 is attached to the groove 61e.

The sheet 62 has a tapered recess 62a into which the seal portion 61b of the spool 61 can be fitted. A communication hole 62b communicating with the first hydraulic port P1 is formed at the bottom of the recess 62a. The spring 63 is disposed on the outer periphery of the body portion 61 a of the spool 61 and acts to press the seal portion 61 b of the spool 61 against the concave portion 62 a of the sheet 62.

Here, when the O-ring 64 of the seal portion 61b is pressed against the recess 62a of the seat 62 by the spring 63, the hydraulic oil from the first hydraulic port P1 does not flow into the third oil chamber Q3. On the other hand, when the hydraulic pressure of the hydraulic oil supplied from the first hydraulic pressure port P1 becomes relatively higher than the hydraulic pressure on the third oil chamber Q3 side, and the differential pressure between the two becomes a predetermined value or more, the spool 61 is spring-loaded. It moves to the third oil chamber Q3 side against the urging force of 63. In this state, the hydraulic oil from the first hydraulic port P1 flows into the recess 62a from the communication hole 62b of the seat 62, and further flows into the third oil chamber Q3 through the vertical hole 61d and the horizontal hole 61c of the spool 61. .

The open valve Vo is mounted inside the second cylindrical portion 17c of the turbine hub 17 at a location where the phase in the circumferential direction is different from that of the main valve Vc (for example, a position corresponding in the radial direction). Similarly to the main valve Vc, the release valve Vo is disposed in a stepped hole formed in the second cylindrical portion 17c and penetrating in the axial direction. When the hydraulic pressure on the third oil chamber Q3 side is relatively higher than the hydraulic pressure on the first oil chamber Q1 side, the release valve Vo communicates the third oil chamber Q3 and the first oil chamber Q1 (first hydraulic port P1). Then, the hydraulic oil in the third oil chamber Q3 and the adjustment oil chamber R is discharged.

As shown in FIG. 7, the release valve Vo has a spool 71 that can move in the axial direction, a seat 72, and a spool guide 73.

The spool 71 has the same configuration as the spool 61 of the main valve Vc, although the assembled direction is different. That is, it has the trunk | drum 71a and the seal | sticker part 71b. A horizontal hole 71c and a vertical hole 71d are formed in the body portion 71a. An annular groove 71e is formed in the seal portion 71b, and an O-ring 74 is disposed in the groove 71e.

The seat 72 has the same configuration as the seat 62 of the main valve Vc, although the assembled direction is different. That is, it has a tapered recess 72a, and a communication hole 72b communicating with the third oil chamber Q3 is formed at the bottom of the recess 72a.

The spool guide 73 is disposed in the hole of the second cylindrical portion 17c and is formed in a cylindrical shape. The body 71a of the spool 71 is slidable through the hole 73a inside the spool guide 73. A large diameter recess 73 b is formed at the end of the spool guide 73. When the end surface of the seal portion 71b of the spool 71 comes into contact with the recess 73b, the movement of the spool 71 in the axial direction is restricted.

Here, when the hydraulic pressure on the first oil chamber Q1 (first hydraulic port P1) side is relatively higher than the hydraulic pressure on the third oil chamber Q3 side, the seal portion 71b of the spool 71 is pressed against the recess 72a of the seat 72. The hydraulic oil in the third oil chamber Q3 and the adjustment oil chamber R is not discharged to the first oil chamber Q1 (first hydraulic port P1) side. On the other hand, if the oil pressure on the first oil chamber Q1 (first oil pressure port P1) side is relatively lower than the oil pressure on the third oil chamber Q3 side, the hydraulic oil in the third oil chamber Q3 and the adjusting oil chamber R is the first. The oil is discharged to the oil chamber Q1 (first hydraulic port P1) side.

[Operation of lock-up device]
FIG. 8 shows the hydraulic control flow for the lockup device and the state of the lockup device at that time. The upper part of the figure shows the oil pressure (left vertical axis) of each part with respect to the elapsed time (horizontal axis) and the displacement of the piston 30 and the connecting member 40 (right vertical axis). Note that “displacement” is not an absolute movement amount but a ratio (%) when the maximum displacement is 100%. In the lower part of the figure, the movement of the piston 30 and the connecting member 40 in each stage of hydraulic control is shown.

In the following description, the state of transmitting torque in the first clutch portion 28 and the dog clutch 32 is described as “(clutch) on”. The state where torque transmission is released in each clutch is referred to as “(clutch) off”.

8, C1 indicates the hydraulic pressure of the first oil chamber Q1, C2 indicates the hydraulic pressure of the second oil chamber Q2, and C3 indicates the hydraulic pressure of the dog oil chamber Qd. Dp represents the displacement of the piston 30 and Dd represents the displacement of the connecting member 40.

<First stage I (lock-up off)>
The first stage shows a torque transmission state by the torque converter body 6. In this case, the hydraulic pressure C2 of the hydraulic oil supplied from the second hydraulic port P2 is relatively high, and the hydraulic pressure C2 of the second oil chamber Q2 is higher than the hydraulic pressures C1 and C3 of the first oil chamber Q1 and the dog oil chamber Qd. Is expensive. Therefore, both the first clutch portion 28 and the dog clutch 32 are off, and the torque input to the front cover 2 is transmitted to the turbine 4 via the torque converter body 6. That is, lock-up off.

<Second stage II (lock-up on)>
When the engine speed increases to a predetermined engine speed, the process proceeds to the second stage. In the second stage, the hydraulic pressure C1 of the hydraulic oil supplied from the first hydraulic pressure port P1 increases from the hydraulic pressure of the first stage. On the other hand, the hydraulic pressure C2 of the hydraulic oil supplied from the second hydraulic pressure port P2 decreases. Accordingly, the hydraulic pressure C1 of the first oil chamber Q1 is higher than the hydraulic pressure C2 of the second oil chamber Q2, the piston 30 moves to the front cover 2 side, and the first clutch portion 28 is turned on. That is, the lockup is turned on.

In this second stage, the main valve Vc remains closed. Therefore, the hydraulic pressure C3 of the dog oil chamber Qd is maintained as it is in the first stage, and the connecting member 40 does not move to the front cover 2 side. That is, the connecting member 40 meshes with the second ring gear 42, but does not mesh with the first ring gear 41, and the dog clutch 32 remains off.

In this state, torque from the front cover 2 is transmitted to the piston 30 and further transmitted to the turbine 4 via the damper mechanism 34.

<Third stage III → fourth stage IV (transition to mechanical connection)>
After maintaining the state of the second stage for a predetermined time, the process proceeds to the third stage. In this third stage, the hydraulic pressure C2 of the hydraulic oil supplied from the second hydraulic pressure port P2 is further lowered while maintaining the hydraulic pressure C1 of the first oil chamber Q1. At this time, since the hydraulic oil (hydraulic pressure) in the dog oil chamber Qd is maintained in the second stage, the oil pressure C3 in the dog oil chamber Qd is changed to the second oil chamber by lowering the oil pressure C2 in the second oil chamber Q2. It becomes higher than the hydraulic pressure C2 of Q2. For this reason, the connecting member 40 moves to the front cover 2 side, the differential pressure between the first oil chamber Q1 and the dog oil chamber Qd becomes larger, and the main valve Vc opens.

When the main valve Vc is opened, the hydraulic oil from the first hydraulic port P1 flows into the dog oil chamber Qd (the third oil chamber Q3 and the adjusting oil chamber R) via the main valve Vc. Here, when the hydraulic oil flows into the adjustment oil chamber R, the bellows 44 is compressed. Then, the hydraulic pressure C3 of the dog oil chamber Qd rises to the hydraulic pressure C1 of the first oil chamber Q1.

Thus, when the oil pressure C3 of the dog oil chamber Qd rises to the oil pressure C1 of the first oil chamber Q1, the connecting member 40 moves to the front cover 2 side. However, at this time, there may be a case where the teeth 40a on the outer peripheral surface of the connecting member 40 collide with the end surfaces of the teeth 41a of the first ring gear 41 and are not engaged with each other. FIG. 8 shows a state where the displacement Dd of the connecting member 40 is stopped in the middle.

Therefore, the next stage IV is entered. In the fourth stage, the hydraulic pressure C1 of the hydraulic oil supplied from the first hydraulic pressure port P1 is lowered to a predetermined hydraulic pressure. This predetermined hydraulic pressure is such that the first clutch portion 28 slips. Thus, by causing the first clutch portion 28 to slip, relative rotation occurs between the connecting member 40 (second ring gear 42) and the first ring gear 41 (front cover 2). For this reason, the phase of the tooth 40a of the connection member 40 and the tooth 41a of the 1st ring gear 41 shifts, and mutual collision is avoided. As a result, the connecting member 40 reliably meshes with the first ring gear 41. Moreover, since the chamfer is formed in the end surface of the tooth | gear 40a of the connection member 40, it will mesh more smoothly.

In the second half of the fourth stage, the first hydraulic port P1 and the second hydraulic port P2 are connected to the drain, and the hydraulic oil in the first oil chamber Q1 and the second oil chamber Q2 is discharged. As a result, the hydraulic pressures C1 and C2 of the first and second oil chambers Q1 and Q2 become “0”. Further, since the oil pressure in the dog oil chamber Qd is relatively higher than the oil pressure in the first oil chamber Q1, the release valve Vo is opened, the hydraulic oil in the dog oil chamber Qd is also discharged, and the oil pressure C3 becomes “0”. Become. At this time, the bellows 44 that has been compressed so far is stretched.

Here, the torque input to the front cover 2 is transmitted to the piston 30 via the dog clutch 32 and then transmitted to the turbine 4 via the damper mechanism 34. That is, lock-up on by mechanical connection.

Further, in this state, since the hydraulic oil is not supplied to the first oil chamber Q1, the first clutch portion 28 does not transmit torque. Further, since the hydraulic oil is not supplied also to the second oil chamber Q2, it is not necessary to drive a pump for supplying the hydraulic oil. That is, it is possible to transmit the torque input to the front cover 2 to the turbine 4 while maintaining the lock-up state without supplying hydraulic oil to the torque converter.

<Fifth stage V (lock-up on by mechanical connection)>
The fifth stage is a lock-up state in which torque from the front cover 2 is mechanically transmitted to the turbine 4 via the dog clutch 32. In the fifth stage, the displacement of the piston 30 is the same as that of the fourth stage, but here, the pressing force by the hydraulic oil does not act on the piston 30. Therefore, in the fifth stage, the first clutch portion 28 is off. In this state, as described above, the first hydraulic port P1 and the second hydraulic port P2 are connected to the drain, and the hydraulic pressures C1, C2, and C3 of each chamber are “0”. That is, the lockup state can be maintained without supplying hydraulic oil to the lockup device.

The sixth stage and the seventh stage show the hydraulic control when releasing the lockup state from the lockup state. Here, the lock-up state is a state where torque is mechanically transmitted only by the dog clutch 32. If the dog clutch 32 is turned off from such a state, the clutch does not slip as a transition state, so that a shock may occur when the dog clutch 32 is turned off.

Therefore, here, when changing from the lock-up state to the lock-up release state, the dog clutch 32 is turned off after the first clutch portion 28 is turned on, and then the first clutch portion 28 is turned off.

Specifically, first, hydraulic fluid is supplied from the first hydraulic port P1, and the hydraulic pressure C1 of the first oil chamber Q1 is raised. As a result, the friction member 28 fixed to the piston 30 is pressed against the front cover 2 and the first clutch portion 28 is turned on. In this state, torque from the front cover 2 is transmitted not only to the dog clutch 32 but also to the damper mechanism 34 and the turbine 4 via the first clutch portion 28.

Thereafter, the hydraulic oil is supplied from the second hydraulic port P2 with a delay from the increase in the hydraulic pressure C1 in the first oil chamber Q1, and the hydraulic pressure C2 in the second oil chamber Q2 is increased to a predetermined hydraulic pressure. At this time, although the main valve Vc is closed, the hydraulic oil in the third oil chamber Q3 flows into the adjusting oil chamber R inside the connecting member 40 by the bellows 44 being compressed. As a result, the connecting member 40 moves to the second ring gear 42 side. For this reason, the meshing between the connecting member 40 and the first ring gear 41 is released, and the dog clutch 32 is turned off.

Here, when the lockup is released, the first clutch portion 28 is once turned on and then the dog clutch 32 is turned off, so that the lock is turned on compared to the case where the dog clutch 32 is turned off without turning on the first clutch portion 28. Shock when releasing up can be suppressed.

Then move on to the 7th stage. The hydraulic pressure and displacement of each part of the seventh stage are the same as those of the first stage. Here, since the hydraulic pressure C2 of the second oil chamber Q2 is higher than the hydraulic pressure C1 of the first oil chamber Q1, the piston 30 moves away from the front cover 2, and the first clutch portion 28 is completely turned off.

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

(A) In the above embodiment, the first clutch portion is a friction member fixed to the piston, but it may be a multi-plate clutch having a plurality of clutch plates. Moreover, although the 2nd clutch part was made into the dog clutch, if the torque is transmitted mechanically other, the structure is not limited.

(B) In the above embodiment, the front cover and the piston are mechanically connected by the second clutch portion, but the torque transmission path is not limited to this. For example, the front cover and the input member of the damper mechanism may be mechanically coupled by the second clutch portion.

In the lock-up device for a torque converter and the control method thereof according to the present invention, in the lock-up state, in the device that mechanically connects the front cover and the output side to eliminate the need to supply hydraulic oil in the lock-up state, The shock at the time of shifting from the up state to the lockup release state can be suppressed.

1 Torque converter 2 Front cover 4 Turbine 7 Lock-up device 17 Turbine hub (output member)
28 Friction member (first clutch part)
30 piston (torque transmission member)
32 dog clutch (second clutch part)
40 connecting member 41 first ring gear 42 second ring gear Vc main valve (first valve)
Vo release valve (second valve)
Q1 First hydraulic chamber Q2 Second hydraulic chamber Q3 Third hydraulic chamber R Regulating oil chamber Qd Dog oil chamber P1 First hydraulic port P2 Second hydraulic port

Claims

A torque converter lock-up device that is arranged between a front cover and a turbine and transmits or interrupts torque,
Actuated by hydraulic oil, and at the time of transition between the lock-up release state and the lock-up state, a torque transmission state is established between the front cover and the turbine. A first clutch portion for releasing torque transmission with the turbine;
A torque transmission member disposed between the first clutch part and the turbine, and transmitting torque from the first clutch part to the turbine;
A connecting member capable of mechanically connecting the front cover and the torque transmission member by sliding in the axial direction with hydraulic oil, and the front cover and the torque transmission member in a locked-up state by the operation of the connecting member; Between the front cover and the torque transmission member in a lock-up release state, and a second clutch portion for releasing the connection between the front cover and the torque transmission member,
Torque converter lockup device with
A first hydraulic port for supplying hydraulic oil for bringing the first clutch part into a torque transmitting state and operating the connecting member to bring the second clutch part into a connected state;
A second hydraulic pressure port for supplying hydraulic oil to bring the first clutch part into a torque transmission release state and actuate the connecting member to bring the second clutch part into a release state;
The torque converter lockup device according to claim 1, further comprising:
The torque transmission member is a piston movable in the axial direction by hydraulic oil,
The first clutch portion includes a friction member fixed to the piston, and the friction member is pressed by the front cover to transmit torque between the front cover and the piston,
A connecting member of the second clutch portion mechanically connects the front cover and the piston;
The lockup device for a torque converter according to claim 2.
The second clutch part is
A first ring gear provided on the front cover and having a plurality of teeth on an inner peripheral surface;
A second ring gear provided on the piston and having a plurality of teeth on an inner peripheral surface;
Have
The connecting member has a plurality of teeth on the outer peripheral surface that can mesh with the teeth of the first ring gear and the second ring gear.
The lockup device for a torque converter according to claim 3.
The first clutch portion, the second clutch portion, and an output member that outputs torque from the turbine are further provided, and the output member includes a disc-shaped flange and a cylinder that extends from the flange toward the axial front cover side. And having a shape part,
The connecting member is supported on the outer peripheral surface of the cylindrical portion of the output member so as to be slidable in the axial direction.
The torque converter lockup device according to claim 4.
An oil chamber is formed between the connecting member and the output member,
The first hydraulic port is provided in the oil chamber when the difference between the hydraulic oil pressure from the first hydraulic port and the hydraulic oil pressure from the second hydraulic port is equal to or greater than a predetermined value. A first valve for introducing hydraulic oil from
The lockup device for a torque converter according to claim 5.
The apparatus according to claim 6, further comprising a second valve that is provided in the output member and that guides the hydraulic oil in the oil chamber when the hydraulic oil pressure supplied from the first hydraulic port becomes a predetermined value or less. The torque converter lockup device described.
The connecting member is
An adjustment oil chamber whose internal volume can be changed;
A communication oil passage communicating the oil chamber and the adjustment oil chamber;
have,
The torque converter lockup device according to claim 6 or 7.
A first clutch portion that is actuated by hydraulic oil to transmit or release torque between the front cover and the turbine; a torque transmission member that transmits torque from the first clutch portion to the turbine; A lockup device having a second clutch part that mechanically connects or disconnects the front cover and the torque transmission member by an operating connection member, wherein the first clutch part is in a connected state. Is a control method for releasing the lock-up state from the lock-up state in which the torque transmission is released,
A first step of bringing the first clutch portion into a torque transmitting state while maintaining the second clutch portion in a connected state;
A second step of removing the connection of the second clutch part while maintaining the torque transmission state of the first clutch part;
A third step of bringing the first clutch part into a torque transmission release state after the connection of the second clutch part is released;
A method for controlling a lockup device including:
In the first step, a first hydraulic pressure is applied to the first clutch portion to achieve a torque transmission state,
In the second step, in a state where the first hydraulic pressure is applied to the first clutch portion, a second hydraulic pressure lower than the first hydraulic pressure is applied to the second clutch portion to connect the second clutch portion. To release,
The control method of the lockup apparatus of Claim 9.