JPH0544745A - Fluid pressure coupling device - Google Patents

Abstract

PURPOSE:To reduce any interference with a braking system of a fluid pressure coupling device which is suitable for an automobile four-wheel drive device. CONSTITUTION:In a fluid pressure coupling device which transmits torque in space between two rotational systems by means of a vane pump structure, a working fluid is pressurized to this vane pump structure according to a rotational speed difference between two rotational systems, and there is provided a vane 17 which performs torque transfer between these two rotational systems through this working fluid pressure. In addition, there are provided two resistance flow passages 27, 101 regulating a torque transfer value to the rotational speed difference by letting the working fluid at the high pressure side flow into the vane 17 in keeping with some resistance to the low pressure side, and each passage resistance of these resistance flow passages 27, 101 should be set so as to make it smaller than at time of normal rotation at the time of reverse of the vane 17 as its constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure joint device for transmitting torque by a fluid pressure generated according to a difference in rotational speed between two rotary shafts, and particularly suitable for use in a four-wheel drive system for automobiles. The present invention relates to a fluid pressure coupling device.

[0002]

2. Description of the Related Art For example, in a four-wheel drive system in which front wheels and rear wheels are driven by the same engine, a tight corner braking phenomenon is prevented from occurring due to a difference in rotation speed between the front wheels and the rear wheels, and 2. Description of the Related Art A so-called full-time four-wheel drive type vehicle has been developed which has a drive coupling device for distributing driving force to front and rear wheels according to a rotational speed difference between the front and rear wheels.

As this drive coupling device, a differential (center differential) for absorbing the rotational speed difference is provided between the front and rear wheels, and a diff lock mechanism (or a viscous coupling for restricting the operation) of the front and rear wheels is provided. And a single viscous coupling has been developed.

However, in the case where the center diff is provided, it is difficult to downsize the center diff, which causes an increase in weight of the vehicle body and an increase in manufacturing cost. In addition, a diff lock mechanism and a viscous coupling for ensuring four-wheel drive performance are provided. Since it is necessary, the device is complicated. In addition, the one provided with the viscous coupling alone has a torque transmission characteristic that the transmission torque gradually decreases as the rotation difference increases, and the vehicle has a very small friction coefficient on a road surface such as sand, muddy snow, or snow. When traveling on a vehicle, unless the rotational difference between the front and rear wheels is large, torque cannot be transmitted to the wheels on the driven side, which may cause slipping on the wheels on the main driving side.

Therefore, as an alternative to the mist with a center differential and the viscous coupling, a fluid pressure coupling device has been developed as a drive coupling device for appropriately transmitting torque from the front wheel side to the rear wheel side by fluid pressure.

This fluid pressure coupling device transmits torque from the input shaft to the output shaft by the fluid pressure generated according to the rotational speed difference between the main drive side input shaft and the slave drive side output shaft. Is. For example, in a four-wheel drive vehicle in which the driving force from an engine mounted on the front of the vehicle body is transmitted directly to the front wheels and to the rear wheels via a propeller shaft, this fluid pressure coupling device is Attach to the middle part. In this case, the front wheel side of the propeller shaft corresponds to the input shaft, the rear wheel side of the propeller shaft corresponds to the output shaft, and the rotation speed difference between the input shaft and the output shaft is the difference between the front and rear wheels. Corresponding to.

The structure of this fluid pressure coupling device will be described. As shown in FIG. 10, this fluid pressure coupling device has, for example, a cam ring 11 that rotates integrally with an output shaft (not shown).
And a rotor 12 that rotates integrally with an input shaft (not shown). A shaft member 13 is serrated to the rotor 12.

A plurality of (
Three recesses are formed here, and this recess and the rotor 1
The oil chamber 2 that functions as a pump chamber between the outer peripheral surface
1 is formed.

Inside the pump chamber 21, a plurality of vanes 17 are provided, and the vanes 17 divide each pump chamber 21 into a discharge side chamber and a suction side chamber.

These vanes 17 are mounted in a large number of grooves 18 formed in the rotor 12 so as to be able to move forward and backward in the radial direction, and the tips thereof are in sliding contact with the inner peripheral surface of the cam ring 11. Particularly, here, each vane 17 is biased in the radial direction by a spring (not shown).
Further, an orifice 27 communicating with the discharge side chamber and the suction side chamber is provided on the upper portion of each vane 17.

Suction and discharge ports (suction and discharge ports) 21a and 21b are formed at both ends of the pump chamber 21, and the suction and discharge ports 21a and 21b are formed by the vanes 17.
When it becomes a discharge side chamber, it becomes a discharge port (discharge port), and when it becomes a suction side chamber, it becomes a suction port (suction port).

When a difference in rotation occurs between the input shaft and the output shaft, the rotor 12 rotates relative to the cam ring 11, and the vane 17 drives the hydraulic oil inside each pump chamber 21.

That is, when the rotor 12 rotates relative to the cam ring 11, the vane 17 pressurizes the hydraulic oil in front of the vane 17 in the pump chamber 21, and the suction / discharge port 21b side in front of the vane 17 moves. While serving as a discharge side chamber (high pressure chamber), a suction discharge port 21a behind the vane 17
The side is the suction side chamber (low pressure chamber). At the same time, in each pump chamber 21, hydraulic oil flows from the discharge side chamber to the suction side chamber through the orifice 27 of the vane 17.

By the way, the hydraulic oil is generated by the orifice 27.
The flow path resistance acts in a direction to prevent relative rotation of the rotor 12 with respect to the cam ring 11 when passing through the rotor 12.
It is controlled through the hydraulic fluid so that the difference between the rotational speeds of the two is reduced. For example, when the cam ring 11 tries to over-rotate with respect to the rotor 12, a part of the rotational torque on the cam ring 11 side is transmitted to the rotor 12 through the hydraulic oil.

By the action of such a fluid pressure coupling device, the torque from the engine is rotated at an appropriate ratio between the front wheel side and the rear wheel side, that is, the front wheel and the rear wheel are always rotated at substantially the same speed. , Distributed, the four-wheel drive state is realized. As a result, the slip of each wheel is suppressed and the drive torque can be efficiently transmitted to the road surface.

[0016]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a four-wheel drive vehicle equipped with the fluid pressure coupling device as described above, AB
If S (anti-lock braking system) is also provided, the fluid pressure coupling device may interfere with the ABS, which is not preferable.

That is, in the above fluid pressure coupling device, the working fluid flows from the high pressure side to the low pressure side while receiving the resistance of the orifice 27, so that the differential rotation (rotational speed difference) between the two rotary shafts (input shaft and output shaft). ) Is allowed, the torque transmission amount between the two rotary shafts increases as the rotational speed difference increases.

For example, curves a and b in FIG. 11 show the characteristic of the torque transmission amount with respect to the rotational speed difference, and it is known that the torque transmission characteristic with respect to the rotational speed difference changes depending on the shape and size of the orifice 27. There is. In the above fluid pressure coupling device, the orifice 27 is set so that a desired torque transmission characteristic (for example, the characteristic indicated by the curve a) can be obtained.

The torque transmitted according to the orifice 27 as described above has a higher rotational speed on the input shaft side than on the output shaft side when the vane 17 rotates forward (that is, when the vane 17 moves forward) from the input shaft side to the output shaft side. The rotation speed of the output shaft side is faster than that of the input shaft side when the vane 17 rotates in the reverse direction (that is, when the vane 17 rotates reversely). It is also performed when the rotation is transmitted.

In forward drive, the vane 17 is generally used.
Normally rotates, and conversely, during forward braking, the vanes 17 generally reversely rotate, and torque is transmitted between the front wheel side and the rear wheel side in both cases, but when such torque transmission is performed during braking, This leads to a reduction in braking performance during ABS operation.

The shape of the orifice 27 is the vane 17
A circular hole (cylindrical hole) is the most simple and preferable in terms of workability, but in order to stabilize the torque transmission characteristics, for example, as shown in FIG. It is considered that the low-pressure side) is partially chamfered into a conical surface to rectify the flow of the working fluid passing through the orifice 27 during normal rotation.

As a result, the torque transmission characteristic as shown by the curve a in FIG. 11 can be stably obtained. But,
In the case of this example, the working fluid at the time of reverse rotation may be less likely to be rectified than at the time of normal rotation. For example, as shown by the curve b in FIG. 11, the torque transmission characteristic at the time of reverse rotation is more than that at the time of normal rotation. When the braking force is increased, a large torque is likely to be transmitted during braking, and the braking performance may be deteriorated during ABS operation.

On the other hand, considering the backward movement of the vehicle, the vane 17 generally reverses when the vehicle is driven in reverse. Therefore, in order to perform four-wheel drive with a torque transmission characteristic according to the difference in rotational speed when the vehicle moves backward, the vane 17 is driven. It is necessary to operate the resistance flow path such as the orifice 27 even when reversing.

The present invention was devised in view of the above problems, and an object thereof is to provide a fluid pressure coupling device capable of reducing interference with a braking system.

[0025]

Therefore, the fluid pressure coupling device according to claim 1 of the present invention is a fluid pressure coupling device for transmitting rotational torque between two rotary systems by means of a vane pump structure, wherein the vane pump structure is provided. A vane is provided to pressurize the working fluid in accordance with the rotational speed difference between the two rotary systems and transmit torque between the two rotary systems through the working fluid pressure, and the working fluid on the high pressure side is supplied to the vane at a low pressure. A resistance flow passage is provided to adjust the amount of torque transmission with respect to the rotational speed difference by circulating with the resistance on the side, and the flow passage resistance of the resistance flow passage is smaller when the vane rotates in the reverse direction than in the normal rotation. The feature is that it is set to be.

A fluid pressure coupling device according to a second aspect of the present invention is a fluid pressure coupling device for transmitting rotational torque between two rotary systems by means of a vane pump structure, wherein the vane pump structure rotates the two rotary systems. A vane is provided for pressurizing the working fluid according to the speed difference and transmitting torque between the two rotary systems through the working fluid pressure, and the working fluid on the high pressure side flows through the vane with resistance to the low pressure side. By doing so, a resistance flow path for adjusting the torque transmission amount with respect to the rotational speed difference is provided, and a sub resistance flow path for reducing the flow path resistance of the working fluid on the high pressure side to the low pressure side when the vane is reversed is provided. It is characterized by

[0027]

In the fluid pressure coupling device according to the first aspect of the present invention described above, the resistance passage for adjusting the torque transmission amount with respect to the rotational speed difference by causing the working oil on the high pressure side to flow through the vane with resistance to the low pressure side. Since the flow path resistance of is set to be smaller when the vane rotates in the reverse direction than in the normal rotation, the torque transmission amount with respect to the rotational speed difference is smaller when the vane rotates in the reverse direction than when the vane rotates in the normal direction. ..

In the fluid pressure coupling device according to the second aspect of the present invention described above, since the flow resistance of the hydraulic oil on the high pressure side to the low pressure side is reduced during the reverse rotation of the vane through the auxiliary resistance flow passage, the rotational speed difference is reduced. The amount of torque transmitted to the vane is smaller when the vane rotates in the reverse direction than when the vane rotates in the normal direction.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show a fluid pressure coupling device as a first embodiment of the present invention, and FIG. ,
2 is a cross-sectional view of a main part thereof (a cross-sectional view taken along the line AA of FIG. 1), FIG. 3 is a cross-sectional view thereof, FIG. 4 is a vertical cross-sectional view thereof, FIG. 5 is a perspective view of its main parts, and FIG. FIG. 7 is a cross-sectional view of a main part of the vane when the vane rotates normally, FIG. 7 is a cross-sectional view of the main part of the vane when the vane rotates reversely, and FIG. FIG. 9 is a sectional view showing a vane of a fluid pressure coupling device as a third embodiment of the present invention.

The fluid pressure coupling device of the first embodiment will be described. The overall configuration of this fluid pressure coupling device is substantially the same as that of the conventional example. For example, a cam ring 11 that rotates integrally with the output shaft, When the input shaft and the rotor 12 rotate integrally with each other and a rotation difference occurs between the input shaft and the output shaft, the rotor 12 and the cam ring 11 relatively rotate,
The vane 17 drives hydraulic oil as a working fluid inside each pump chamber 21 to transmit torque.

That is, as shown in FIGS. 3 to 5, the fluid pressure coupling device includes a first rotary shaft 8A and a second rotary shaft 8B.
And a cam ring side portion 10a which is interposed between the first rotating shaft 8A and the first rotating shaft 8A and a rotor side portion 10b which integrally rotates with the second rotating shaft 8B.

The cam ring side portion 10a is the cam ring 1
1, end housings 15 and 16 connected to both ends of the cam ring 11, a spacer 15A joined to the end housing 15, and the cam ring 11, the end housings 15 and 16 and the spacer 15A so as to cover them. It has a cover member 30 attached thereto.

The spacer 15A, the end housing 15, the cam ring 11 and the end housing 16 are integrally connected with each other by a plurality of bolts 37 which penetrate the spacer 15A and are screwed into the end housing 16. Of these, the end housing 16 is coupled to the end flange 8a of the first rotating shaft 8A.

Both ends of the cover member 30 are fitted in the end housings 15 and 16 and are fixed by stopper rings 47, and the gaps between the cover member 30 and the cam ring 11, the end housings 15 and 16 and the spacer 15A therein are provided. Is a tank 30a capable of hermetically storing working oil as working fluid. A seal member 45 is interposed between each of these members.

The end portion housing 16 is provided with an oil passage 16a communicating with the inside of the tank 30a. This oil passage 16a
Supplies hydraulic oil into the tank 30a and is closed by the taper plug 48 after the supply.

On the other hand, the rotor side portion 10b is connected to the rotor 12
And a shaft member 13 serration-coupled to the rotor 12.
And a volume change absorbing piston 39 mounted on the end of the shaft member 13, and a spring 4 for urging the piston 39.
It has 0.

Of these, the shaft member 13 has a bearing 4
The end housings 15, 16 are connected via 3, 44, respectively. A gap formed between the shaft member 13 and each of the end housings 15 and 16 is an oil chamber 49, and both ends of the oil chamber 49 are covered with a seal member 42 and a lid member 46 with a sealing function. It is densified.

The seal member 42, the bearing 43,
44 and the lid member 46 are stoppers 42a, 4 respectively.
It is fixed at 3a, 44a and 46a.

Further, pump chambers 21, 22 and 23 are formed between the outer circumference of the rotor 12 and the cam ring 11. That is, as shown in FIG. 3, a plurality of (here, three) recesses are formed on the inner periphery of the cam ring 11, and these recesses are surrounded by the inner surfaces of the end housings 15 and 16 and the outer peripheral surface of the rotor 12, Oil chamber 2 that functions as a chamber
1, 22, 23 are formed.

A plurality of vanes 17 are provided inside the pump chambers 21, 22 and 23, and the vanes 17 divide the pump chambers 21, 22 and 23 into a discharge side chamber and a suction side chamber. It is designed to be used.

These vanes 17 are mounted in a large number of grooves 18 formed in the rotor 12 so as to be able to move forward and backward in the radial direction, and the tips thereof are in sliding contact with the inner peripheral surface of the cam ring 11. In particular, here each vane 17 has a spring 2
6 urges it in the radial direction. In addition, an orifice 27 as a main resistance flow passage that connects the discharge side chamber and the suction side chamber is provided on the upper portion of each vane 17.

At the base of the groove 18 of the rotor 12, the expanded diameter portion 1
9 are formed, and pressure chambers 20 that communicate the expanded diameter portions 19 with each other with the end housing 15 are formed at both ends of the large diameter expanded portions 19.

At both ends of the pump chambers 21, 22, 23, suction and discharge ports (suction and discharge ports) 21a, 21b,
22a, 22b, 23a, 23b are formed, and these suction and discharge ports 21a to 23b are partitioned by the vane 17 and become discharge ports (discharge ports) when they become discharge side chambers, and when they become suction side chambers. It serves as a suction port (suction port).

The tank 30a and each pump chamber 21 to
A working fluid supply path (hereinafter, simply referred to as an oil path) 2 so as to individually communicate with the respective suction and discharge ports 21a to 23b of 23.
4a to 25c and check valves 33a to 34c are provided.

That is, in the end housings 15 and 16 and the spacer 15A, the suction / discharge ports 21a, 21b, 22a, 22b, 23a, 2 of the pump chambers 21, 22, 23 are provided.
3b and the oil passages 24a, 2 for communicating the tank 30a with each other
5a, 24b, 25b, 24c, 25c are bored, and along with this, the respective suction / discharge ports 21a, 21b, 22.
Oil passages 31a, 32a, 31b, 32b, 31c, 32c that connect the pressure chambers 20 with a, 22b, 23a, 23b.
Has been drilled.

These oil passages 24a, 25a, 24b, 2
5b, 24c, 25c, 31a, 32a, 31b, 32
b, 31c, 32c, check valves 34a,
34b, 34c, 33a, 33b, 33c, 35a, 3
5b, 35c 36a, 36b, 36c are interposed.

On the other hand, a flange portion 13a is formed at one end of the shaft member 13, and the flange portion 13a is the second portion.
Is connected to the end flange 8b of the rotary shaft 8B. A piston chamber 38 is formed inside the flange portion 13a, and a volume change absorbing mechanism 14 including a volume change absorbing piston 39 and a spring 40 is provided.

In other words, the shaft center of the shaft member 13 is provided with a hole 13b which penetrates to both ends and communicates with the oil chamber 49.
A piston chamber 38 having a diameter larger than that of the hole 13b is provided at one end of the shaft member 13. The piston 39 is provided in sliding contact with the piston chamber 38 so as to be able to move forward and backward, and is biased by the spring 40 toward the hole 13b side.

A retainer 41 is fixed to the open end of the piston chamber 38 by a stopper ring 41a, and a recess 39a is formed on the rear surface of the piston 39. One end of the spring 40 is attached to the retainer 41. The piston 39 is equipped with the other end locked in the recess 39a of the piston 39.

Further, the piston 39 has a piston chamber 3
8 is equipped with a sealing member 39b that seals the gap between the two. An oil passage 50 is bored between the oil chamber 49 and the inside of the tank 30a so that the oil chamber 49 and the inside of the tank 30a have substantially the same pressure.

The working oil is supplied into the tank 30a through the oil passage 16a and is hermetically stored therein. At the time of this storage, the working oil is pressurized to a predetermined pressure. Against the proper decline.

By the way, the thickness of each vane 17 is set to be slightly smaller than the width of the groove 18, and a lubricating oil film is formed by the working oil that has entered the gap between the vane 17 and the groove 18. Thus, each vane 17 can smoothly move up and down in the groove 18.

As shown in FIGS. 1 and 2, each vane 17 is provided with another orifice 101 in addition to the orifice 27. This orifice 101 is
Vane 1 is formed at the required position under each vane 17.
Even when 7 is most protruded in the pump chambers 21, 22, 23, the orifice 101 is not exposed from the groove 18.

On the other hand, a notch 102 is formed at the opening of each groove 18, and the orifice 101 and the notch 102 form a sub resistance flow path. Further, a resistance flow path is constituted by the sub resistance flow paths 101 and 102 and the orifice 27 as a main resistance flow path.

This notch 102 is, as shown in FIG.
Wall surfaces 18a, 18 on which the vane 17 slides in the groove 18
Of b, it is formed in the opening of the wall surface 18b of the rotor 12 and the vane 17 on the forward rotation direction side.

As shown in FIG. 2, the notch 102 is partially formed in the longitudinal direction of the groove 18 (in the middle of the vertical direction in FIG. 2). Two
Orifice 101 when protruding most among 1, 22, 23
Are set so as to completely open in the notch 102.

The above-mentioned forward rotation direction is the relative rotation direction of the rotor 12 and the vane 17 with respect to the cam ring 11 during forward drive, and in this example, the rotor 12 and the vane 17 have the cam ring 11 in FIG. On the other hand, it is the case of rotating to the right. On the other hand, during forward braking, the relative rotation directions of the rotor 12 and the vane 17 with respect to the cam ring 11 are opposite (in FIG. 1, the rotor 12 and the vane 17 are opposite).
It rotates counterclockwise with respect to the cam ring 11) of FIG.

The shapes of the orifices 27 and 101 are
One of the circular holes (the low-pressure side at the time of forward rotation) is partially chamfered to form a conical surface, and the orifice 27 at the time of forward rotation is formed.
It is designed to rectify the flow of working fluid passing through and obtain stable torque transmission characteristics.

With the above-described structure, in the fluid pressure coupling device of this embodiment, when a difference in rotation occurs between the input shaft and the output shaft, the rotor 12 rotates relative to the cam ring 11 and each vane 17 causes the rotor 12 to rotate. The hydraulic oil inside the pump chambers 21 to 23 is driven.

That is, when the rotor 12 rotates relative to the cam ring 11, the vane 17 moves the pump chambers 21-2.
3 pressurizes the hydraulic oil in front of the vane 17 inside, and the suction and discharge ports 21b to 23b on the front side of the vane 17 serve as the discharge side chamber, while the suction and discharge port 2 behind the vane 17
The suction side chamber is located on the side of 1a to 23.

At the same time, in each pump chamber 21-23,
The working oil flows from the discharge side chamber to the suction side chamber through the orifice 27 of the vane 17, but when the working oil passes through the orifice 27, the working oil receives a resistance according to the flow rate, and this flow path resistance is It acts in a direction that impedes relative rotation with respect to the cam ring 11, and the rotor 12 and the cam ring 11
Is controlled through the hydraulic oil so that the difference in rotational speed between them is reduced.

For example, when the cam ring 11 tries to over-rotate with respect to the rotor 12, a part of the rotational torque on the cam ring 11 side is transmitted to the rotor 12 through the hydraulic oil.

By the action of such a fluid pressure joint device, the torque from the engine is rotated at an appropriate ratio between the front wheel side and the rear wheel side, that is, the front wheel and the rear wheel are always rotated at substantially the same speed. The four-wheel drive state in which the wheels are distributed and the slip of each wheel is suppressed and the drive torque is efficiently transmitted to the road surface is realized.

The torque transmission characteristic obtained through the orifice 27 is, for example, as shown by a curve a in FIG. 11 with respect to the differential rotation (rotational speed difference) between the cam ring 11 and the rotor 12, but in this fluid pressure coupling device, An orifice 101 is provided as a resistance flow path in addition to the orifice 27, and the orifice 101 acts only when the rotor 12 and the vane 17 rotate in the reverse direction, so that the torque transmission amount decreases during the reverse rotation.

That is, at the time of forward rotation, as shown in FIG.
The vane 17 tilts toward the low pressure side (suction and discharge port 21a side),
Since the side surface of the vane 17 comes into contact with the opening end of the wall surface 18a of the groove 18 (see reference numeral A), the low pressure side (suction / discharge port 21a side) is no longer in communication with the orifice 101,
Only the orifice 27 is provided as a flow path from the high pressure side (suction and discharge port 21b side) of the pump chamber 21 to the low pressure side (suction and discharge port 21a side). Therefore, the torque transmission characteristic during normal rotation is as shown by the curve a in FIG.

The vane 17 is inclined in the groove 18 because
This is because the thickness of the vane 17 is set to be slightly smaller than the width of the groove 18 so that the vane 17 can smoothly move up and down in the groove 18, and in reality, this inclination is slight. In FIG. 7, the inclination is emphasized more than the actual one for easier understanding.

On the other hand, at the time of reverse rotation, as shown in FIG. 7, the vane 17 is inclined toward the low pressure side (suction and discharge port 21b side), and the side surface of the vane 17 comes into contact with the opening end of the wall surface 18b of the groove 18. Since the notch 102 is provided at the opening end of the wall surface 18b, when the low pressure side of the pump chamber 21 communicates with the groove 18 and the vane 17 rises, the orifice 101 is opened in the notch 102. Therefore, as shown by the arrow in FIG. 7, the hydraulic oil on the high pressure side is discharged from the gap between the wall surface 18a of the groove 18 and the side surface of the vane 17 into the orifice 1
01 Further, it becomes possible to enter the low pressure side through the notch 102.

In this way, during reverse rotation, the pump chamber 2
Since the flow path from the high pressure side (suction and discharge port 21b side) of 1 to the low pressure side (suction and discharge port 21a side) is formed not only in the orifice 27 but also in the portion of the orifice 101, the flow path resistance is reduced accordingly. The torque transmission characteristics during reverse rotation are shown in FIG.
Curve c, which is smaller than that during normal rotation.

As a result, the vane 1 is generally driven during forward drive.
7 rotates in the normal direction, and a required amount of torque transmission is obtained with respect to the differential rotation. On the other hand, during forward braking, generally vane 1
7 reversely rotates, and a torque transmission amount appropriately smaller than that in the normal rotation is obtained with respect to the differential rotation.

Since the amount of torque transmission during braking is small in this way, it is likely to occur due to torque transmission between the front and rear wheels.
It is possible to reduce deterioration of braking performance during BS operation.

Further, when the vehicle moves backward, the vanes 17 reversely rotate during reverse driving, but as described above, some torque is transmitted even during reverse rotation, so that reverse driving also requires four-wheel drive with proper torque distribution. realizable.

Further, the shape of the orifice 27 is such that one of the circular holes (low pressure side during normal rotation) is partially chamfered into a conical surface so that stable torque transmission characteristics can be obtained during normal rotation. In consideration of the above, larger torque transmission is more likely to occur during reverse rotation, but even in such a case, the torque transmission amount during reverse rotation can be sufficiently reduced by the orifice 101 that acts only during reverse rotation as described above.

Next, the second embodiment will be described. The overall structure of the fluid pressure coupling device is substantially the same as that of the first embodiment, and the vane 17 and its vicinity are different from those of the first embodiment.

That is, the vane 17 has an orifice 27.
In addition to the above, another orifice (sub resistance flow path) 101 is provided.
The valve 103 is provided so as to be exposed to the outside from the groove 18 at the time of protrusion of the valve 103. The valve 103 is opened only when the vane 17 rotates in the reverse direction.

In this fluid pressure joint device, the notch 102 as in the first embodiment is not provided. Further, FIG. 8 emphasizes the open state of the valve 103, and the valve 103 is actually set so as not to be exposed from the surface of the vane 17.

With such a configuration, the flow path resistance at the time of reverse rotation becomes small, the torque transmission amount at the time of reverse rotation becomes smaller than that at the time of forward rotation, and the same effect as in the first embodiment can be obtained.

Explaining the third embodiment, the overall structure of the fluid pressure coupling device is substantially the same as that of the first and second embodiments, and the vane 17 and its vicinity are different from those of the first and second embodiments. ing.

That is, the vane 17 has an orifice 27.
In addition to the above, another orifice (auxiliary resistance flow path) 104 with a check ball is provided. This orifice 10
The check ball of No. 4 is designed to open the flow path only when the vane 17 is reversed.

In this fluid pressure coupling device, the cutout 102 as in the first embodiment is not provided.

With this configuration, the flow path resistance during reverse rotation is reduced, the torque transmission amount during reverse rotation is smaller than during normal rotation, and the same effects as those of the first and second embodiments are obtained.

Incidentally, the sub resistance flow passages are those
Not only 1, 103, 104, but one having a valve function that allows the flow only in one direction (the flow direction of hydraulic oil during reverse rotation), or the direction of flow in one direction (circulation direction of hydraulic oil during reverse rotation) However, an orifice or the like having a directivity with a small resistance may be used.

In particular, in a directional orifice or the like, it may be provided as a main resistance passage instead of the auxiliary resistance passage instead of as the auxiliary resistance passage. In this case, the sub resistance flow path can be omitted.

[0083]

As described in detail above, the first aspect of the present invention
According to the fluid pressure coupling device of the present invention, in the fluid pressure coupling device which transmits the rotational torque between the two rotary systems by the vane pump structure, the working oil is pressurized to the vane pump structure according to the difference in rotational speed of the two rotary systems. A vane is provided for transmitting torque between the two rotary systems through the working fluid pressure, and the working oil on the high pressure side is circulated through the vane with resistance to the low pressure side to transmit the torque for the difference in rotational speed. A resistance flow path for adjusting the amount is provided so that the flow path resistance of the resistance flow path is set to be smaller when the vane rotates in the reverse direction than during normal rotation. It is possible to reduce the amount of torque transmission when the vanes reversely rotate, and to reduce the interference with the braking system such as ABS of the fluid pressure coupling device.

According to the fluid pressure joint device of the second aspect of the present invention, in the fluid pressure joint device for transmitting the rotational torque between the two rotary systems by the vane pump structure, the vane pump structure is provided with the two rotary system. A vane is provided for pressurizing hydraulic oil according to the rotational speed difference and transmitting torque between the two rotary systems through the hydraulic fluid pressure. The vane is provided with hydraulic oil on the high pressure side and resistance on the low pressure side. A resistance flow passage is provided to adjust the amount of torque transmission with respect to the rotational speed difference by flowing, and a sub resistance flow passage is provided to reduce the flow resistance of the hydraulic oil on the high pressure side to the low pressure side when the vane is reversed. With such a configuration, it is possible to reduce the amount of torque transmission at the time of reverse rotation of the vane, such as during braking, through the sub resistance flow path, and reduce the interference with the braking system such as ABS of the fluid pressure coupling device. .

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts of a fluid pressure coupling device as a first embodiment of the present invention.

FIG. 2 is a sectional view (a sectional view taken along the line AA of FIG. 1) of a main part of a fluid pressure coupling device according to a first embodiment of the present invention.

FIG. 3 is a transverse sectional view of a fluid pressure coupling device as a first embodiment of the present invention.

FIG. 4 is a vertical sectional view of a fluid pressure coupling device as a first embodiment of the present invention.

FIG. 5 is a perspective view of a main part of a fluid pressure coupling device according to a first embodiment of the present invention.

FIG. 6 is a cross-sectional view of the main parts of the fluid pressure coupling device according to the first embodiment of the present invention when the vane is normally rotated.

FIG. 7 is a cross-sectional view of essential parts of the fluid pressure coupling device according to the first embodiment of the present invention when the vanes are reversed.

FIG. 8 is a cross-sectional view of essential parts of a fluid pressure coupling device according to a second embodiment of the present invention.

FIG. 9 is a sectional view of essential parts of a fluid pressure coupling device as a third embodiment of the present invention.

FIG. 10 is a cross-sectional view of a conventional fluid pressure coupling device.

FIG. 11 is a diagram showing torque transmission characteristics of a fluid pressure coupling device.

FIG. 12 is a cross-sectional view of essential parts of a conventional fluid pressure coupling device.

[Explanation of symbols]

8A 1st rotating shaft 8B 2nd rotating shaft 10a Cam ring side part 10b Rotor side part 11 Cam ring 12 Rotor 13 Shaft member 17 Vanes 18 Groove 18a, 18b Wall surface 19 of groove 18 Expanded part 21,22,23 Pump chamber 21a , 21b to 23a, 23b Suction / discharge port (suction / discharge port) 27 Orifice (main resistance flow passage) 101 Orifice (sub resistance flow passage) 102 Notch (sub resistance flow passage) 103 Valve 104 Orifice with check ball (sub resistance flow) Road)

Claims (2)

[Claims] 1. A fluid pressure coupling device for transmitting a rotational torque between two rotary systems by a vane pump structure, wherein the working fluid is pressurized to the vane pump structure in accordance with a difference in rotational speed between the two rotary systems. 2 through pressure
A vane for transmitting torque between two rotary systems is provided, and a resistance flow passage for adjusting the amount of torque transmission with respect to the rotational speed difference by causing the working fluid on the high pressure side to flow through the vane with resistance to the low pressure side. Is provided, and the flow passage resistance of the resistance flow passage is set to be smaller when the vane rotates in the reverse direction than when the vane rotates in the normal direction. 2. A fluid pressure coupling device for transmitting rotational torque between two rotary systems by means of a vane pump structure, wherein the working fluid is pressurized to the vane pump structure in accordance with the difference in rotational speed between the two rotary systems. 2 through pressure
A vane for transmitting torque between two rotary systems is provided, and a resistance flow passage for adjusting the amount of torque transmission with respect to the rotational speed difference by causing the working fluid on the high pressure side to flow through the vane with resistance to the low pressure side. And a sub resistance flow passage for reducing flow resistance of the working fluid on the high pressure side to the low pressure side when the vane is reversed, the fluid pressure coupling device.