JP2731463B2 - Hydraulic power transmission coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic power transmission coupling used for distributing driving force of a vehicle.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed a hydraulic power transmission coupling as described below in Japanese Patent Application No. 1-133662. That is, the hydraulic power transmission coupling includes a hydraulic pump driven by a rotational speed difference between a first rotatable member and a second rotatable member that are rotatable relative to each other, and a fluid from the hydraulic pump connected to one high pressure. A hydraulic power transmission coupling, wherein the hydraulic power transmission coupling includes a collecting means for collecting the fluid in the chamber, and a means for generating a flow resistance of the fluid, wherein a transmission torque between the first and second rotating members is controlled by the flow resistance. A relief hole communicating with the chamber, a needle valve (relief valve) integrally formed with the flywheel, which can open and close the relief hole, and a spring for setting a relief pressure for pressing the needle valve against the relief hole with a predetermined load. When the vehicle is suddenly decelerated, the pressure oil in the high-pressure chamber is relieved, the joint is set in a free state, and interference with the ABS is prevented.

[0003]

However, in such a conventional hydraulic power transmission coupling, since the relief valve has a structure for receiving the hydraulic reaction force of the high-pressure chamber, the relief valve is not relieved in a normal state. Had to be pushed with a strong spring. In order to open the relief valve in view of the spring force, a large flywheel is required, and there is a problem that the joint becomes large and heavy.

In addition, since the relief valve is provided at the center of the shaft, the joint cannot be formed as a through-the-shaft type, and there is a problem that there is a restriction in mounting the vehicle. The present invention has been made in view of such a conventional problem. By reducing the size of the flywheel, the joint can be reduced in size and weight, and the position of the relief valve can be changed. Accordingly, it is an object of the present invention to provide a hydraulic power transmission coupling having no restrictions on mounting on a vehicle.

[0005]

In order to achieve the above object, the present invention is provided between input / output shafts which are rotatable relative to each other,
A hydraulic pump driven by the differential rotation of the two shafts;
A high-pressure chamber for collecting oil discharged from the hydraulic pump; a flow resistance generating means provided at an outlet from the high-pressure chamber to a low-pressure chamber in the joint; a hydraulic pressure transmitting torque corresponding to a rotational speed difference between the two shafts In a power transmission coupling, a member forming a high-pressure chamber therein is provided with a spool-shaped relief valve for releasing pressure oil in the high-pressure chamber, and is positioned so as to be rotatable relative to the member by a predetermined angle, and the relative rotation Sometimes, a flywheel having a cam surface formed on its side surface for controlling the opening and closing of the relief valve, and a spring for constantly biasing the flywheel in the forward acceleration direction of the vehicle are provided. Only when the flywheel rotates relative to the member, opening the relief valve.

[0006]

In the present invention, when a deceleration of a predetermined value or more is applied to the flywheel, the flywheel relatively rotates against a member forming a high-pressure chamber therein against a spring, and the relief valve is provided with It is released along the cam surface formed on the flywheel. Thus, the joint is free.

In this case, since no hydraulic reaction force is generated in the relief valve, a large force is not required for its operation, and the flywheel can be downsized. As a result, the joint can be reduced in size and weight. In addition, since the relief valve can be arranged away from the center of the shaft, the joint can be of a through-shaft type, and there is no restriction on mounting on a vehicle.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing an embodiment of the present invention.
First, the structure will be described. In FIG.
The cam 1 has a cam surface 2 having one or more ridges. The cam 1 is positioned at a housing 4 to which an output shaft is connected via a spline 3 so as to be rotatable at a predetermined angle, and rotates integrally with the housing 4.

Reference numeral 5 denotes a rotor rotatably housed in the housing 4. The rotor 5 is connected to an input shaft 6 and rotates integrally with the input shaft 6. A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction, and a plurality of plungers 8 are slidably housed in the plunger chamber 7 via a return spring 9. Further, a plurality of suction / discharge holes 10 are formed in the rotor 5 so as to communicate with each plunger chamber 7.

Reference numeral 11 denotes a rotary valve fixed to the housing 4 and rotatably supporting the input shaft 6 via a bearing 12 and having a high-pressure chamber 13 formed therein. Suction port 1
4, a suction path 15, and a discharge port 16 are formed. The discharge port 16 and the high-pressure chamber 13 communicate with each other through a communication passage (not shown), and the high-pressure chamber 13 and the low-pressure chamber in the housing 4 communicate with each other through an orifice (not shown) as flow resistance generating means.

The rotary valve 11 is connected to the housing 4.
Has a not-shown positioning projection that engages with a not-shown notch formed on the inner periphery of the. Also, the rotary valve 1
As shown in FIG. 2, reference numeral 1 denotes a spool hole 17, an oil escape groove 18 formed continuously below the spool hole 17, a stopper 19, and a small hole 21 for hooking a coil spring 20.
Are formed, and the spool hole 17 is provided in the high-pressure chamber 13.
A spool valve 22, which is a relief valve for releasing the pressure oil, is mounted via a leaf spring 23.

The spool valve 22 has a high pressure chamber 1 at the time of sudden deceleration.
An outer peripheral groove 24 communicating the oil discharge groove 18 with the groove 3 is formed. 25 is a flywheel, flywheel 2
5 is rotatably supported on the input shaft 6 via a bearing 26 on the back side of the rotary valve 11. The flywheel 25 has a control cam surface 27 for driving the spool valve 22, a notch 28 for positioning relative to the rotary valve 11 so as to be rotatable by a predetermined angle,
A small hole 29 for hooking a coil spring 20 which generates a predetermined rotational force with the rotary valve 11 and constantly urges the vehicle in the forward acceleration direction is formed (see FIG. 3).

As shown in FIG. 4, the coil spring 20 has a bent end 30 inserted into a small hole 21 of the rotary valve 11.
And a bent end portion 31 inserted into the small hole 29 of the flywheel 25. In addition, the rotary valve 11 includes:
A pin 32 is provided at an axially symmetric position with the spool valve 22, and the pin 32 urges the flywheel 25 in the same direction as the spool valve 22.

As shown in FIG. 5, a spool hole 33 into which the pin 32 and the spool valve 22 are inserted and a pin hole 34 are formed in the leaf spring 23, and the spool valve 2
The convex portions 35 and 36 provided on the intermediate line between the pin 2 and the pin 32 are used as load supporting points. The leaf spring 23 always biases the spool valve 22 in the opening direction, and positions the pin 32 so as to be movable in the axial direction. The pin 32 has a function of preventing rotation of the balance and spring. That is, the pin 32 is
Of the leaf spring 23 itself and the misalignment of the leaf spring 23 itself. A one-way valve 38 having an orifice 37 is provided at the bottom of the spool hole 17 of the rotary valve 11 to delay the return after the operation.

The rotary valve 11 and the flywheel 25 are formed in a ring shape and are arranged concentrically with respect to the joint shaft, but the spool valve 22 is provided at a distance from the axis. Reference numeral 39 denotes an accumulator piston which rotates integrally with the housing 4.
Moves according to the internal pressure. Accumulator piston 39
A return spring 41 is interposed between the and the retainer 40. 42 and 43 are oil seals, 4
Reference numerals 4 and 45 are stopper rings, and 46 and 47 are needle bearings.

Next, the operation will be described. Cam 1 and rotor 5
When there is no rotation difference between the plunger 8 and the plunger 8, the plunger 8 does not operate and no torque is transmitted. At this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9. Next, when a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8 in the discharge stroke is pushed in the axial direction by the cam surface 2 of the cam 1.

At this time, the suction / discharge port 10 is connected to the discharge port 16
Plunger 8 is in plunger room 7
Is pushed out from the suction / discharge port 10 to the discharge port 16 of the rotary valve 11. The oil pushed out to the discharge port 16 is discharged to the low pressure chamber through the communication passage and the orifice. At this time, the hydraulic pressure in the communication passage, the discharge port 16 and the plunger chamber 7 increases due to the resistance of the orifice, and a reaction force is generated in the plunger 8. By rotating the cam 1 against this plunger reaction force, a torque is generated, and the torque is transmitted between the cam 1 and the rotor 5. Since the discharge ports 16 communicate with each other through the communication passage, the hydraulic pressures of all the plunger chambers 7 in the discharge stroke become equal.

Further, when the cam 1 rotates, a suction stroke occurs, and the suction / discharge port 10 communicates with the suction port 14.
The oil in the suction passage 15 is supplied to the suction port 14, the suction discharge port 1
The plunger 8 is sucked into the plunger chamber 7 through 0 and returns along the cam surface 2 of the cam 1. Here, FIG.
As shown in FIG. 3A, the stopper of the rotary valve 11 is actuated in the normal state or the accelerated state in which the coil spring 20 for urging the flywheel 25 in the forward acceleration direction of the vehicle is acting as shown by the arrow D. 19 is engaged with the notch 28 for positioning the flywheel 25, and the spool valve 22 is in a closed state.

This normal state or acceleration state is shown in FIG.
The spool valve 22 is closed, and the pressure oil in the high-pressure chamber 13 does not escape from the spool valve 22. Next, when the vehicle suddenly decelerates, as indicated by an arrow E in FIG. 6B, a force due to inertial force acts on the flywheel 25, so that the flywheel 25 relatively rotates with the rotary valve 11, and The stopper 19 is locked in the notch 28 on the opposite side, and the spool valve 22 is opened along the cam surface 27 of the flywheel 25 by the urging force of the leaf spring 23.

The state at the time of this rapid deceleration is shown in FIG. 7B. The pressure oil in the high-pressure chamber 13 passes through the outer peripheral groove 24 and escapes from the oil release groove 18 as shown by an arrow G. Thus, the joint is free. Next, at the time of re-acceleration, the force of the coil spring 20 indicated by the arrow F in FIG.
To return to the original closed state along
Since the one-way valve 38 is provided at the bottom of 7, the oil in the spool hole 17 is discharged through the orifice 37 as shown by the arrow H, and it takes time for the spool valve 22 to return. .

Here, when the ABS is operated, as shown in FIG. 8, the rotational speed I of the joint stops while repeating acceleration and deceleration. In the figure, J indicates the vehicle speed, K indicates the angular acceleration at which the vehicle is free, and L indicates the angular acceleration at which the vehicle is turned on. When such acceleration / deceleration acts on the joint, the spool valve 22 repeatedly opens and closes, and the joint becomes free or recovers (see FIG. 8).
For this reason, interference occurs with the operation of the ABS, which may cause the malfunction of the ABS.

In this embodiment, the one-way valve 3
In FIG. 8, the recovery time from the free state is delayed so that the joint maintains the free state during the ABS operation. Therefore, malfunction of the ABS can be prevented. In addition, since the spool valve 22 that does not generate a hydraulic reaction force is used as the relief valve, a large force is not required for its operation, so that the flywheel 25 can be downsized.

As a result, the joint can be reduced in size and weight. Further, since the spool valve 22 is arranged away from the center of the shaft, the joint can be of a through-shaft type, and there is no restriction on mounting on the vehicle.

[0024]

As described above, according to the present invention, since the spool valve which does not generate a hydraulic reaction force is used, the flywheel can be reduced in size, and as a result, the joint can be reduced in size and weight. can do. Further, since the spool valve is arranged away from the center of the shaft, the joint can be of a through-shaft type, and there is no restriction on mounting on a vehicle.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 is a partial perspective view of a rotary valve.

FIG. 3 is a perspective view of a flywheel.

FIG. 4 shows a coil spring.

FIG. 5 shows a leaf spring.

FIG. 6 is an explanatory diagram of an operation.

FIG. 7 shows a normal state and a free state.

FIG. 8 is a diagram showing an ABS operation state;

[Explanation of symbols]

 1: cam 2: cam surface 3: spline 4: housing 5: rotor 6: input shaft 7: plunger chamber 8: plunger 9: return spring 10: suction / discharge hole 11: rotary valve (a member forming a high-pressure chamber) 12: Bearing 13: High pressure chamber 14: Suction port 15: Suction path 16: Discharge port 17: Spool hole 18: Oil escape groove 19: Stopper 20: Coil spring 21: Small hole 22: Spool valve (relief valve) 23: Leaf spring 24: Outer circumferential groove 25: Flywheel 26: Bearing 27: Cam surface 28: Notch 29: Small hole 30, 31: Bend end 32: Pin 33, 34: Hole 35, 36: Convex portion 37: Orifice 38: One-way valve 39: accumulator piston 40: retainer 41: return spring 42, 43: oil seal 44 45: stopper ring 46, 47: needle bearing

Claims (4)

(57) [Claims] 1. A hydraulic pump provided between input and output shafts rotatable relative to each other and driven by differential rotation of the two shafts; a high pressure chamber for collecting oil discharged from the hydraulic pump; A hydraulic resistance transmission means for transmitting a torque corresponding to the rotational speed difference between the two shafts; a high-pressure chamber provided inside a member forming the high-pressure chamber; A flywheel having a spool-shaped relief valve for releasing pressure oil, and a cam surface formed on a side surface thereof, the cam surface being positioned to be rotatable relative to the member by a predetermined angle and controlling opening and closing of the relief valve during relative rotation. A wheel and a spring that constantly biases the flywheel in the forward acceleration direction of the vehicle, and only when a predetermined or more deceleration is applied to the flywheel, the flywheel moves relative to the member. Rolling, and hydraulic power transmission joint, characterized by opening the relief valve. 2. A hydraulic system according to claim 1, wherein a one-way valve having a flow resistance generating function is provided at an end of said relief valve which is not driven by said flywheel, and the return of said relief valve is delayed. Type power transmission coupling. 3. The hydraulic power transmission coupling according to claim 1, wherein the member and the flywheel are formed in a ring shape, and the relief valve is provided on the joint shaft at a distance from the axis. 4. A disk-shaped, ring-shaped leaf spring for constantly biasing the relief valve in the direction of opening, and attaching the flywheel in the same direction as the relief valve at a position axially symmetrical with the relief valve of the leaf spring. A biasing pin, and the pin is movably positioned in the axial direction between a member forming a high-pressure chamber therein; and two projections provided on an intermediate line between the relief valve and the pin of the leaf spring. The hydraulic power transmission coupling according to claim 1, wherein the portion is a load fulcrum.