JP3494503B2 - Torque converter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque converter, and more particularly to a torque converter in which a piston member of a lockup clutch is arranged on the front cover side.

[0002]

2. Description of the Related Art A torque converter disclosed in Japanese Patent Laid-Open No. 2-245562 has a lockup clutch having a piston member arranged on the front cover side.
In such a lockup clutch, the hydraulic pressure in the torque converter and the operating pressure for operating the piston member are separated. The space between the piston member and the front cover communicates with the oil passage formed in the front cover to the oil passage formed in the main drive shaft extending from the transmission side.

In the conventional example, a one-way throttle valve is arranged between the oil passage in the main drive shaft and the control valve. With this one-way throttle valve, the hydraulic oil is supplied from the control valve side to the space between the front cover and the piston member while being throttled, and the hydraulic oil is quickly discharged from the space. This is because the lockup pressure is gradually increased by gradually bending the piston member when the clutch is engaged, and as a result, the shock when the lockup is engaged is alleviated.

Further, in such a lockup clutch, the piston member is engaged with the front cover so as to rotate integrally therewith. This is because the piston is likely to rotate relative to the front cover when vibration is transmitted from the engine side or when acceleration / deceleration is performed, and therefore it is prevented. As a structure for preventing the rotation, conventionally, a pin is press-fitted inside the front cover, and an engaging concave portion into which the pin is inserted is formed on the piston member side.

[0005]

In the above conventional torque converter, the space between the front cover and the turbine hub is
Bushings and thrust bearings are arranged. If the sealing performance deteriorates due to wear on this bushing,
The hydraulic oil that has passed through the oil passage in the main drive shaft may leak from the bush portion. For this reason,
The operating pressure of the lockup clutch is unstable or drops. In particular, the hydraulic oil flowing through the oil passage in the main drive shaft has a small flow rate because it is throttled by the one-way throttle valve when the lockup clutch is connected, and if there is a leak from the bush portion, it has a great influence. However, providing a seal member near the bush increases the cost, and thus should be avoided.

The piston member is generally made of aluminum in order to prevent a large amount of inertia. for that reason,
The engagement recess of the piston member is likely to wear due to the sliding of the pin and the engagement recess when the clutch is engaged or disengaged. As the wear of the engagement recess progresses, the function of the piston member to prevent rotation is reduced. An object of the present invention is to prevent the lockup operating pressure from being significantly reduced while suppressing the cost.

Another object of the present invention is to ensure detent of the piston member.

[0008]

According to a first aspect of the present invention, there is provided a torque converter for transmitting torque to a shaft having an oil passage extending from a transmission side to an engine side and having an opening at an end thereof. . The torque converter includes an input side front cover, an impeller, an output side turbine, a turbine hub, a lockup clutch, an oil passage, and a one-way throttle valve. The input side front cover has a central portion facing the tip of the shaft with a gap.
The impeller is fixed to the front cover and forms a hydraulic oil chamber together with the front cover. The output side turbine is arranged to face the impeller in the hydraulic oil chamber. The turbine hub is fixed to the turbine and is non-rotatably connected to the shaft. The lock-up clutch is installed in the hydraulic oil chamber in close proximity to the front cover while ensuring a space, and the disc-shaped piston member whose inner and outer peripheral edges are axially movably supported by the front cover and the turbine hub. It includes a connecting mechanism to be connected and a clutch portion for connecting and disconnecting the front cover and the connecting mechanism by axial movement of the piston member. The oil passage is formed in the front cover and connects the gap and the space. The one-way throttle valve is provided in the oil passage and throttles the oil flowing from the gap to the space.

In this torque converter, the one-way throttle valve is formed in parallel with the check valve for prohibiting the oil from flowing from the gap to the space and allowing the oil to flow from the space to the gap. And a controlled orifice . The check valve includes a valve seat formed on the center line of rotation of the front cover and extending in the axial direction, and a valve body movable in the axial direction.

[0010] In the torque converter according to claim 2, the front cover is formed first cylindrical portion extending toward the transmission, to the turbine hub at the inner circumference side of the first cylindrical portion extending toward the engine A second tubular portion is formed. The torque converter further includes a cylindrical member arranged between the first cylinder portion and the second cylinder portion.

[0011]

[0012]

[0013]

[0014]

In the torque converter according to the first aspect of the present invention, when the front cover rotates, the impeller also rotates, and the working oil flows from the impeller to the output side turbine. As a result, the turbine rotates and torque is transmitted from the turbine hub to the shaft on the transmission side.

For example, the flow rate of the hydraulic oil supplied from the control valve through the oil passage in the shaft is limited by the one-way throttle valve in the oil passage in the front cover. As a result, the hydraulic pressure that operates the piston member when the lockup clutch is engaged gradually increases. At this time, hydraulic oil may leak from the gap between the front cover and the tip of the shaft through the space between the front cover and the turbine. However, since the oil passage is narrowed before the gap between the front cover and the tip of the shaft, even if hydraulic oil leaks from the cylindrical member, the working pressure on the piston member does not drop significantly. .

In this torque converter, the one-way throttle valve has a simple structure including a check valve and an orifice. Further , the valve element moves in the axial direction to open and close the valve seat. Here, since the check valve is formed so as to extend in the axial direction on the rotation center line of the front cover, the centrifugal force due to the rotation of the front cover hardly acts on the valve body.

[0017] In the torque converter according to claim 2, the sealing member only cylindrical member is disposed between the second cylindrical portion of the first cylindrical portion and the turbine hub of the front cover is not disposed. Here, the cost is reduced by omitting the seal member.

[0018]

[0019]

[0020]

[0021]

First Embodiment FIG. 1 shows a torque converter 1 as a first embodiment of the present invention. Here, O-O is a rotation center line of the torque converter 1, an engine (not shown) is arranged on the left side of the drawing, and a transmission (not shown) is arranged on the right side of the drawing. The torque converter 1 is for transmitting torque transmitted from a crankshaft (not shown) on the engine side to a main drive shaft 3 extending from the transmission side. An oil passage 3a is formed at the center of the main drive shaft 3 and extends in the axial direction and has an open end. The oil passage 3a is connected to the control valve 34 and the hydraulic pressure supply source 35.

In the torque converter 1, a disk-shaped front cover 4 and an impeller shell 6 that is engaged with the outer peripheral portion of the front cover 4 so as not to be able to rotate relative to each other and to be removable.
and a form a hydraulic oil chamber 5 in which hydraulic oil is filled. A flange 4a is formed on the outer peripheral portion of the front cover 4, and a flange 6c is formed on the outer peripheral portion of the impeller shell 6a. The flanges 4a and 6c are in contact with each other, and the O-ring 32 is arranged on the inner peripheral side of the contact portion. Also, the flange 6c has a plurality of nuts 3
1 is fixed, and the bolt 30 has both flanges 4a, 6
It penetrates c and is screwed to the nut 31. in this way,
The front cover 4 and the impeller shell 6a are fixed so as to be disassembled.

The front cover 4 is a disk-shaped member made of cast iron. The front cover 4 is centered on the center 4
have c. An oil passage 20 and a one-way throttle valve 21, which will be described later, are arranged in the central portion 4c. An inner peripheral side cylinder portion 4b extending toward the transmission is formed in the central portion 4c. The tip of the main drive shaft 3 is arranged with a slight gap C in the central portion 4c, and is located inside the inner peripheral side cylinder portion 4b.

On the inner surface of the front cover 4 near the middle portion in the radial direction, a plurality of engaging recesses 4d are formed at equal intervals in the circumferential direction. The engagement recess 4d extends in the axial direction. In the hydraulic oil chamber 5, the impeller 6, the turbine 7 and the stator 8 are provided.
A torque converter main body and a lockup clutch 9 are arranged. A plurality of impeller blades 6b are fixed inside the impeller shell 6a, and the impeller 6 is constituted by both. A turbine 7 is arranged at a position facing the impeller 6 in the hydraulic oil chamber 5. The turbine 7 includes a turbine shell 7a and a plurality of turbine blades 7 fixed inside the turbine shell 7a.
and b. The inner peripheral end of the turbine shell 7a is fixed to the turbine hub 17 by a plurality of rivets 16. A spline hole that engages with spline teeth of the main drive shaft is formed on the inner peripheral portion of the turbine hub 17. The turbine hub 17 has a cylindrical portion 17a that extends toward the engine on the inner peripheral side. The cylindrical portion 17 a is arranged between the inner peripheral surface of the inner peripheral side cylindrical portion 4 b of the front cover 4 and the distal end side outer peripheral surface of the main drive shaft 3. A seal member 40 is arranged between the cylindrical portion 17 a and the outer peripheral surface of the main drive shaft 3 on the tip end side. A slight gap is secured between the tubular portion 17a and the inner circumferential side tubular portion 4b, and a cylindrical bush 19 is arranged therein. A thrust bearing 18 is arranged axially between the tip of the inner cylinder 4b and the turbine hub 17.

A stator 8 is arranged between the inner peripheral portion of the impeller 6 and the inner peripheral portion of the turbine 7. Stator 8
Consists of a rotating stator 8A and a fixed stator 8B.
Each of the stators 8A and 8B includes an annular stator carrier 8a and a plurality of stator blades 8b formed on the outer peripheral portion of the stator carrier 8a. Each stator carrier 8a is connected to the shafts 38 and 39 via a one-way clutch mechanism.

The lock-up clutch 9 is arranged axially between the front cover 4 and the turbine 7, and mainly comprises a disc-shaped piston 11, an elastic connecting mechanism 13, a clutch connecting portion 14 and a snap ring. It is composed of 15 and. The piston member 11 is a disc-shaped member, and is arranged close to the front cover 4. Piston member 1
1, the inner and outer peripheral edges of which are slidably supported by the front cover 4 in the axial direction. The piston member 11 has a thin shape with low rigidity in the axial direction and is easily bent, and is integrally formed of, for example, a cast aluminum product. A first space A formed between the piston member 11 and the front cover 4 is a place where the clutch operating hydraulic pressure is generated. In the second space B between the piston member 11 and the turbine shell 7a, the same pressure as in the torque converter body is maintained.

A seal ring 26 is fixed to the outer peripheral edge of the piston member 11 and is in contact with the outer peripheral wall of the front cover 4. The inner peripheral edge of the piston member 11 is in contact with the outer peripheral surface of the inner peripheral side cylinder portion 4b of the front cover 4. A seal ring 27 is arranged on this outer peripheral surface. In this way, the seal rings 26, 27
The space A is sealed from the second space B. The outer peripheral portion of the piston member 11 is arranged on the engine side of the clutch connecting portion 14.

The snap ring 15 is fixed to the outer circumference on the tip end side of the inner peripheral side cylinder portion 4b. When the clutch is disengaged, the distance between the inner peripheral portion of the piston member 11 and the snap ring 15 is larger than the distance between the outer peripheral portion of the piston member 11 and the clutch connecting portion 14. The clutch connecting portion 14 is composed of a drive plate connected to the front cover 4 side and a driven plate connected to the connecting mechanism 13.

The elastic coupling mechanism 13 is fixed to the turbine hub 17 by rivets 16 and has a coil spring and the like. On the outer peripheral side of the piston member 11, a plurality of pins 12 are caulked at equal intervals in the circumferential direction. Each of the pins 12 extends toward the engine and extends into the engagement recess 4d of the front cover 4. By this engagement, the piston member 11 is prevented from rotating on the front cover 4. The pin 12 is induction hardened.

The clearance C between the central portion 4c of the front cover 4 and the tip of the main drive shaft 3 and the first space A
An oil passage 20 communicating with the central portion 4 of the front cover 4 is provided.
It is formed in c. A one-way throttle valve 21 is formed in the middle of the oil passage 20. The one-way throttle valve 21 is
It is composed of a check valve 22 and an orifice 23.
The check valve 22 has a rotation center line O- of the torque converter 1.
It is formed on the O so as to extend in the axial direction. Check valve 22
Consists of a combination of a valve seat 24 having a narrower flow passage toward the engine side and a check ball 25 movably arranged in the axial direction. The orifice 23 communicates with the oil passage 20 so as to act in parallel with the check valve 22.

Next, the operation will be described. The torque from the crankshaft on the engine side is input to the front cover 4. Then, the impeller 6 rotates, and the hydraulic oil flows from the impeller 6 to the turbine 7. The turbine 7 is rotated by the flow of the hydraulic oil, and the torque of the turbine 7 is output to the main drive shaft 3 via the turbine hub 17. The flow of hydraulic oil returning from the turbine 7 to the impeller 6 is adjusted by the stator 8.

When the main drive shaft 3 reaches a certain number of revolutions, the control valve 34 supplies the hydraulic oil from the hydraulic pressure supply source 35 to the oil passage 3a of the main drive shaft 3. This hydraulic oil is supplied from the clearance C through the one-way throttle valve 21 and further from the oil passage 20 to the first space A. By thus increasing the hydraulic pressure in the first space A, the piston member 11 moves to the turbine 7 side. Then, the outer peripheral portion of the piston member 11 contacts the clutch connecting portion 14 to connect the clutch. Next, the piston member 11 flexes in the axial direction as the hydraulic pressure in the first space A increases. As a result, the force on the clutch connecting portion 14 gradually increases. As the deflection of the piston member 11 progresses, the inner peripheral portion of the piston member 11 contacts the snap ring 15 in due course.
As a result, the bending of the piston member 11 is stopped and the clutch pressing force becomes constant. When the above clutch is engaged, the hydraulic oil from the oil passage 3a is supplied to the first space A through the orifice 23. By adjusting the flow passage cross-sectional area of the orifice 23, the time from the contact of the outer peripheral portion of the piston member 11 with the clutch connecting portion 14 to the contact of the inner peripheral portion of the snap ring 15 with the deflection is adjusted. it can. Further, the bush 19 is only arranged between the front cover 4 and the turbine hub 17, that is, between the inner peripheral side cylinder portion 4b and the cylinder portion 17a. Even if the oil leaks, a large amount of hydraulic oil is supplied to the clearance C, so that the hydraulic pressure in the first space A does not drop significantly. This is because the one-way throttle valve 21 is provided in the front cover 4. As a result, it is not necessary to provide a seal member around the bush 19 and the cost is reduced.

When the working oil is discharged from the oil passage 3a by the operation of the control valve 34, the working oil flows from the first space A through the oil passage 20, the one-way throttle valve 21 and the clearance C. At this time, in the one-way throttle valve 21, the hydraulic oil flows through the check valve 22.
Flows quickly from. That is, the lockup connection is released promptly. Since the valve seat 24 of the check valve 22 is formed so as to extend in the axial direction on the rotation center line O-O of the front cover 4, and the check ball 25 is structured to move in the axial direction, the check ball 25 can be placed in front of the check ball 25. The centrifugal force due to the rotation of the cover 4 is hard to act.

When the lockup clutch 9 is in operation, the piston member 11 moves axially forward and backward. At this time, the pin 12 slides in the engagement recess 4d of the front cover 4. However, the front cover 4 is made of cast iron and is hard to wear.
Further, the pins 12 are induction hardened, so that they are not easily worn. Further, since the plurality of engaging recesses 4d and the plurality of pins 12 are arranged in the circumferential direction, the surface pressure is reduced and the wear is less likely to occur. As a result, the rotation stop of the piston member 11 with respect to the front cover 4 can be maintained for a long period of time.

Since the piston member 11 is made of aluminum, the amount of inertia of the piston member 11 can be suppressed and the shock at the time of connecting the lockup clutch can be reduced.
In the case where the pin is provided on the front cover side as in the prior art, aluminum cannot be used on the piston member side because the wear becomes severe. Pin 12 is a disk-shaped piston member 1
It is crimped to 1. The caulking is possible because the pin 12 is provided on the piston member 11 side instead of the front cover 4 side. As a result, the pin 12 is unlikely to loosen even when repeatedly impacted. Further, the axial dimension of the pin 12 becomes smaller than that of the conventional press-fitting. [Other Embodiments] In the above embodiment, the engaging recess 4d and the pin 1 are used.
Although 2 is disposed on the outer peripheral side, it may be disposed on the inner peripheral side.

As shown in FIG. 2, the engaging recesses 4d and the pins 12 may be provided both in the circumferential direction of the outer peripheral portion of the front cover 4 and in the circumferential direction of the inner peripheral portion thereof. In this case, the surface pressure at the engaging portion is reduced and the amount of wear is reduced. The pin 12 may be subjected to another hardening treatment other than induction hardening.

[0037]

In the torque converter according to the aspect of the present invention, the flow rate of the working oil supplied through the oil passage in the shaft is limited by the one-way throttle valve in the oil passage in the center of the front cover. . As a result, the hydraulic pressure that operates the piston member when the lockup clutch is engaged gradually increases. At this time, hydraulic fluid may leak from the gap between the front cover and the tip of the shaft through the front cover and the turbine. However, since the oil passage is narrowed before the gap between the front cover and the tip of the shaft, even if hydraulic oil leaks from the cylindrical member, the working pressure on the piston member does not drop significantly. .

Since the valve seat of the check valve is formed so as to extend in the axial direction on the rotation center line of the front cover, centrifugal force due to the rotation of the front cover hardly acts on the valve body. Only the cylindrical member is arranged between the first cylindrical portion of the front cover and the second cylindrical portion of the turbine hub, and the seal member is not arranged. Here, the cost is reduced by omitting the seal member.

[0039]

[0040]

[0041]

[Brief description of drawings]

FIG. 1 is a schematic partial vertical cross-sectional view of a torque converter as an embodiment of the present invention.

FIG. 2 is a diagram corresponding to FIG. 1 in another embodiment.

[Explanation of symbols]

1 Torque converter 3 Main drive shaft 4 Front cover 6 impeller 7 turbine 9 Lockup clutch 11 Piston member 12 pin 13 Elastic connection mechanism 14 Clutch connecting part 15 snap ring 17 turbine hub 19 bush 20 oil passage 21 One-way throttle valve 22 Check valve 23 Orifice 24 valve seat 25 check balls

Claims (2)

(57) [Claims] 1. A torque converter for transmitting torque to a shaft having an oil passage extending from a transmission side to an engine side and having an opening at an end, the torque converter facing the end of the shaft with a gap. An input side front cover having a central portion, an impeller fixed to the front cover and forming a working oil chamber together with the front cover, an output side turbine arranged to face the impeller in the working oil chamber, and the turbine. The turbine hub is fixed and is connected to the shaft so as not to rotate relative to the turbine hub, and the turbine hub is disposed in close proximity to the front cover while ensuring a space in the hydraulic oil chamber, and inner and outer peripheral edges move axially to the front cover. A disc-shaped piston member supported freely, a coupling mechanism coupled to the turbine hub, and the piston A lock-up clutch including a clutch portion for connecting and disconnecting the front cover and the connecting mechanism by axial movement of a material; and an oil passage formed in the front cover and connecting the gap and the space. , provided in the oil passage, and a one-way throttle valve for throttling the oil flow from the clearance into the space, the one-way throttle valve, oil flow from the clearance into the space
To prevent oil from flowing from the space to the gap.
And a non-return valve that allows the
And a check valve is provided on the center line of rotation of the front cover.
A valve seat formed to extend in the axial direction and movable in the axial direction
A torque converter consisting of a valve body. 2. The front cover is formed with a first cylinder portion extending toward the transmission side, and the turbine hub is formed with a second cylinder portion extending toward the engine side and arranged on the inner peripheral side of the first cylinder portion. is, the first tubular portion and further comprising the placed cylindrical member between said second cylindrical portion, a torque converter according to claim 1.