JPH0587163A - Hydraulic power transmission joint - Google Patents

Abstract

PURPOSE:To prevent the wrong action of ABS, the degradation of running performance and cost increase in a hydraulic power transmission joint used for the driving force distribution of a vehicle. CONSTITUTION:A valve body 11 is provided with two orifices serving as flow resistance generating means. There is provided a spool like switching valve 32 for controlling the conductive state between at least one orifice 35 and a high pressure chamber 31. A cam housing 4 or a member fixed integrally thereto is provided with a cam face 33 for controlling the operation of the switching valve 32 by the position relation with the valve body 11.

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 joint used for distributing a driving force of a vehicle.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed the following hydraulic power transmission joint in Japanese Patent Application No. 2-184735. That is, the hydraulic power transmission joint is provided between the relatively rotatable input / output shafts, is connected to the one shaft, and has a cam housing having a cam surface having two or more ridges on its inner surface; While being connected to the other shaft,
A rotor that is rotatably housed in the cam housing and has a plurality of plunger chambers formed in the axial direction; and a rotor that is reciprocally housed in each of the plurality of plunger chambers under the pressure of a return spring. A plurality of plungers driven by the cam surface when the two shafts rotate relative to each other; an intake / discharge hole formed in the rotor and communicating with the plunger chamber; and an end face of the rotor rotatably slidably contacted, A plurality of intake ports that are positioned in a predetermined relationship with the cam housing and that act as intake valves and discharge valves according to the positional relationship with the intake and discharge holes; A means for generating a flow resistance by the flow of the discharged oil by the driving of the jar; a power for transmitting a torque according to the rotational speed difference between the both shafts. In the universal joint, a communication groove which is provided on a back surface of the valve body where the suction port and the discharge port are not formed and communicates with each of the discharge ports, a lid member which is provided in close contact with the back surface, the communication groove or the The flow resistance generating means is provided between the discharge port and the low pressure chamber.

[0003]

However, when such a conventional hydraulic power transmission coupling is applied to a vehicle with ABS, the differential limiting effect on the front and rear wheels is too high and the ABS malfunctions. There was a problem.
Further, when the torque is reduced, there is a problem that the running performance on a bad road deteriorates.

If a mechanism for separating from the outside is provided,
There is a problem that the cost becomes high. The present invention has been made in view of such conventional problems,
It is an object of the present invention to provide a hydraulic power transmission joint capable of preventing malfunction of ABS and preventing deterioration of running performance and cost increase.

[0005]

In order to achieve the above-mentioned object, the present invention is provided between input / output shafts capable of relative rotation,
A cam housing connected to the one shaft and having a cam surface having two or more ridges on the inner surface; a cam housing connected to the other shaft and rotatably housed in the cam housing; A rotor having a plunger chamber formed in the axial direction; a plurality of plungers housed in each of the plurality of plunger chambers so as to be capable of reciprocating movement, and driven by the cam surface when the two shafts relatively rotate; A suction / discharge hole that opens to one end surface that does not accommodate the plunger of the rotor and communicates with the plunger chamber; rotatably slidably contacts the end surface of the rotor, and is rotatable by a predetermined angle with the cam housing. Is positioned at
A plurality of suction ports that act as a suction valve and a discharge valve according to a positional relationship with the suction and discharge holes, a valve body having a discharge port formed on the surface, and a high-pressure chamber that connects the discharge ports
A means for generating a flow resistance at an outlet portion from the high pressure chamber to the low pressure chamber in the joint is provided; in a power transmission joint for transmitting a torque according to a rotational speed difference between the both shafts, the flow resistance generating means is provided at the valve body. Two orifices are provided, and a spool-shaped switching valve for controlling the electrical connection between at least one of the orifices and the high pressure chamber is provided, and the cam housing or a member fixed integrally with the cam housing is connected to the valve body. A cam surface for controlling the operation of the switching valve according to the positional relationship is provided.

[0006]

In general, the braking force of the vehicle is set so that the front wheel side becomes stronger than the rear wheel side, and the front wheel often tends to lock during ABS operation, and a joint is used for an FF-based vehicle. In this case, the differential direction during ABS operation is opposite to that during forward drive (the same as during reverse drive).

Therefore, when the rotor is rotated in the reverse direction, the switching valve is moved along the cam surface formed on the cam housing or a member fixed integrally with the cam housing, and one of the orifices (sub-orifice) is made conductive. As a result, the torque characteristic at the time of reverse differential can be lowered and the malfunction of the ABS can be prevented. In this case, the torque at the time of reverse travel is also small, but since the torque characteristic itself is a quadratic curve, the required torque can be transmitted at the time of high differential, and there is no practical problem.

Further, since it is not necessary to reduce the torque at the time of forward rotation, the running performance on a bad road is not deteriorated.
Furthermore, since it is not necessary to provide a mechanism for separating from the outside, the cost does not increase.

[0009]

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 configuration will be described. In FIG. 1 and FIG.
Is a cam having a cam surface 2 having two or more ridges on its inner surface, and the cam 1 is connected to the output shaft 3 and rotates integrally with the output shaft 3. The cam 1 is fixed to the cam housing 4, and the cam 1 rotates integrally with the cam housing 4.

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

Reference numeral 11 indicates a suction port 12 and a suction passage 13 on the surface.
And a discharge port 14 are formed in the rotary valve (valve body), and a communication groove 15 communicating with each of the discharge ports 14 is formed on the back surface of the rotary valve 11. A lid member 16 is provided in close contact with the back surface, and the communication groove 15 forms a high-pressure chamber 31 as a whole.

At the outlet from the high pressure chamber 31 to the low pressure chamber in the joint, there is one orifice (flow resistance generating means).
17 is formed. Further, the rotary valve 11 has a positioning projection 19 that engages with a notch 18 formed in the inner circumference of the cam housing 4. Rotary valve 11
Serves as a timing member that determines the opening / closing timing of the suction / discharge hole 10, and the notch 18 and the projection 19 constitute a positioning mechanism that regulates the phase relationship between the cam 1 and the rotary valve 11.

When the plunger 8 is in the suction stroke,
The intake port 12 of the rotary valve 11 and the intake / discharge hole 10 of the rotor 5 communicate with each other, and the orifice 17,
Suction port 12, suction passage 13, suction / discharge hole 1 of rotor 5
Through 0, oil can be sucked into the plunger chamber 7. When the plunger 8 is in the discharge stroke, the relationship is the reverse of the suction stroke, and the suction / discharge hole 10 of the rotor 5 communicates with the communication groove 15 via the discharge port 14 of the rotary valve 11.

Reference numeral 20 is a thrust block that rotates integrally with the cam housing 4, and supports the input shaft 6 via a bearing 21. A needle bearing 22 is interposed between the thrust block 20 and the rotary valve 11, and the friction torque on the needle bearing 22 side is set to be smaller than the friction torque between the rotor 5 and the rotary valve 11. Therefore, when the direction of the differential rotation changes, the rotary valve 11 circulates together with the rotor 5, rotates until the positioning projection 19 of the rotary valve 11 hits the notch 18 of the cam housing 4, and then becomes integral with the cam housing 4. To rotate. As a result, the intake / discharge hole 10 is forcibly opened / closed at a predetermined timing even during normal rotation or reverse rotation.

Reference numeral 23 is an accumulator piston that rotates integrally with the cam housing 4, and the accumulator piston 23 is provided to absorb thermal expansion of the enclosed oil. In addition, 24 is a cover, 25 is a return spring, 26 is an oil seal, 27 is a stopper ring, 28
Is a needle bearing, and 29 is an oiling hole.

A spool hole 30 is formed in the rotary valve 11, and a spool valve which is a switching valve for controlling the conduction state between the high pressure chamber 31 and the second orifice (sub-orifice) 35 is formed in the spool hole 30. 32 is inserted. The thrust block 20 is provided with a cam surface 33 that controls the operation of the spool valve 32 according to the positional relationship with the rotary valve 11.

The high pressure chamber 31 and the sub-orifice 32
The state of communication with is closed by the spool valve 32 when the rotor 5 rotates normally (when driving forward), and is opened by the spool valve 32 when the rotor 5 rotates in reverse (reverse). As shown in FIG. 2, the spool valve 32 has a large diameter portion 32.
A has a small diameter portion 32B and a stepped pressure receiving surface 32C, and the pressure from the high-pressure chamber 31 is constantly applied to the stepped pressure receiving surface 32C, so that it receives a leftward force indicated by an arrow C as shown in FIG. Therefore, the spool valve 32 can move along the cam surface 33 of the thrust block 20 without a spring or the like. In addition, 34 is a blind cover.

Reference numeral 35 is the sub-orifice formed in the rotary valve 11, and the spool hole 30 and the low-pressure chamber communicate with each other via the sub-orifice 35.
The sub-orifice 35 is closed when the spool valve 32 is closed, and the sub-orifice 35 is also opened when the spool valve 32 is opened. Next, the operation will be described.

When there is no rotation difference between the cam 1 and the rotor 5, the plunger 8 does not operate and torque is not transmitted. At this time, the plunger 8 is pressed against the cam surface 2 by the return spring 9. Next, the operation of the rotor 5 during normal rotation will be described. As shown in FIG. 4 (A), during forward rotation when the projection 19 of the rotary valve 11 engages with the notch 18 of the cam housing 4, as shown in FIGS. 5 and 6 (A), the spool valve 32 Is closed by the thrust block 20, the sub-orifice 35 is also closed. In such a state, only the orifice 17 operates.

When the rotor 5 normally rotates in this way,
When a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8 in the discharge stroke is pushed in by the cam surface 2 of the cam 1 in the axial direction. At this time, since the suction / discharge hole 10 communicates with the discharge port 14, the plunger 8 causes the oil in the plunger chamber 7 to flow from the suction / discharge hole 10 to the rotary valve 11.
To the discharge port 14 of.

The oil pushed out to the discharge port 14 is
It is supplied to the suction port 12 through the communication groove 15 and the orifice 17. At this time, the hydraulic pressure in the communication groove 15, the discharge port 14, and the plunger chamber 7 increases due to the resistance of the orifice 17, and a reaction force is generated in the plunger 8. A torque is generated by rotating the cam 1 against the plunger reaction force, and the torque is transmitted between the cam 1 and the rotor 5. Since the discharge port 14 is communicated with the communication groove 15, the hydraulic pressures of all the plunger chambers 7 in the discharge process are equal.

Further, when the cam 1 rotates, a suction stroke is started, and the suction / discharge hole 10 communicates with the suction port 12, so that
The oil in the suction passage 13 is supplied to the suction port 12 and the suction / discharge hole 1.
It is sucked into the plunger chamber 7 via 0, and the plunger 8 returns along the cam surface 2 of the cam 1. The torque T is shown in FIG.
As indicated by A, the torque characteristic increases as the square of the differential rotation speed ΔN.

Next, the operation of the rotor 5 during reverse rotation will be described. Generally, the braking force of the vehicle is set so that the front wheel side is stronger than the rear wheel side, and the front wheels often tend to lock when ABS is operating. The differential direction of is opposite to that when driving forward (the same as when moving backward).

That is, the positional relationship between the rotary valve 11 and the cam housing 4 is as shown in FIG.
The spool valve 32, on which the pressure oil in the high pressure chamber 31 acts, moves along the cam surface 33 of the thrust block 20 and opens.
Therefore, as shown by the arrow D in FIG.
The pressure oil No. 1 escapes to the low pressure chamber side through the sub-orifice 35.

Therefore, due to the action of the orifice 17 and the sub-orifice 35, the torque characteristic shown in FIG. 7B is obtained. At the time of this reverse differential, the torque characteristic can be lowered in this way, so that a malfunction of the ABS can be prevented. In this case, the torque when going backward is also small,
Since the torque characteristic itself is a quadratic curve, the required torque can be transmitted and there is no practical problem.

Since the torque is not reduced during normal rotation, the running performance on a bad road is not deteriorated. Moreover, since it is not necessary to provide a mechanism for separating from the outside, the cost does not increase. When the rotor 5 is switched between forward rotation and reverse rotation, the suction port 12 and the discharge port 1
Since the relationship of 4 is reversed, no pressure is generated in the high pressure chamber 31.

Therefore, the spool valve 32 is provided in the high pressure chamber 3
Although the structure is such that it is pressed against the cam surface 33 by the pressure inside 1, hydraulic pressure is not generated in the spool valve 32 when switching between forward and reverse rotation, and rotation of the rotary valve 11 with respect to the cam housing 4 is not blocked. Absent.
Next, FIGS. 8 and 9A and 9B are views showing another embodiment of the present invention.

In FIG. 8, a spool valve 37 is radially inserted into an insertion hole 36 into which the blind cover 34 in the above embodiment is inserted. Then, on the inner peripheral surface of the cam housing 4, there is formed a cam surface 38 for controlling the entrance and exit of the spool valve 37. As shown in FIG. 9A, the spool valve 37 is closed by the notch 18 of the cam housing 4 when the rotor 5 rotates normally. Therefore, the sub-orifice 35
Does not conduct. The torque characteristic in this case is shown in A of FIG.

On the other hand, as shown in FIG.
During reverse rotation, the spool valve 37 moves along the cam surface 38 of the cam housing 4, and the sub-orifice 35 is brought into conduction. The torque characteristic in this case is shown in B of FIG. Also in this embodiment, the same effect as that of the above embodiment can be obtained. In this embodiment, one spool valve 32 controls the opening and closing of the sub-orifice 35, but two spool valves may be used to control the orifice 17 and the sub-orifice 35, respectively. ..

[0030]

As described above, according to the present invention, the orifice acts during normal rotation and the orifice and sub-orifice act during reverse rotation.
At the time of reverse rotation, the torque characteristic can be lowered, and the malfunction of the ABS can be prevented. Normal torque characteristics can be obtained during normal rotation, and running performance on rough roads is not deteriorated. Further, since it is not necessary to provide a function for separating from the outside, the cost does not increase.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view of a spool valve.

FIG. 3 is an explanatory view of a force acting on a spool valve.

FIG. 4 is a diagram showing a positional relationship between a rotary valve and a cam housing during forward rotation and reverse rotation.

FIG. 5 is a diagram showing the operation of the spool valve during normal rotation.

FIG. 6 is a diagram showing the operation of the spool valve during normal rotation and during reverse rotation.

FIG. 7 is a graph showing torque characteristics.

FIG. 8 is a diagram showing another embodiment of the present invention.

FIG. 9 is a diagram showing the operation of the spool valve during normal rotation and during reverse rotation.

[Explanation of symbols]

 1: Cam 2: Cam surface 3: Output shaft 4: Cam housing 5: Rotor 6: Input shaft 7: Plunger chamber 8: Plunger 9: Return spring 10: Suction / discharge hole 11: Rotary valve (valve body) 12: Suction port 13: Suction path 14: Discharge port 15: Communication groove 16: Lid member 17: Orifice (flow resistance generating means) 18: Notch 19: Protrusion 20: Thrust block 21: Bearing 22: Needle bearing 23: Accumulator piston 24 : Cover 25: Return spring 26: Oil seal 27: Stopper ring 28: Needle bearing 29: Oiling hole 30: Spool hole 31: High pressure chamber 32: Spool valve (switching valve) 32A: Large diameter part 32B: Small diameter part 33C: Step Pressure receiving surface 33: Cam surface 34: Blind cover 35: Sub-orifice Space (flow resistance generating means) 36: Insertion hole 37: Spool valve (switching valve) 38: Cam surface

Claims (2)

[Claims] 1. A cam housing provided between relatively rotatable input / output shafts, connected to said one shaft, and having a cam surface having two or more ridges on its inner side surface; connected to said other shaft. And a rotor having a plurality of plunger chambers axially formed therein and rotatably housed in the cam housing; reciprocally housed in each of the plurality of plunger chambers; A plurality of plungers driven by the cam surface during relative rotation of the rotor;
An inlet / outlet hole communicating with the plunger chamber; rotatably slidably contacting an end surface of the rotor and positioned so as to be rotatable by a predetermined angle with the cam housing, and an inlet valve depending on a positional relationship with the inlet / outlet hole. And a flow valve is formed at the outlet from the high-pressure chamber to the low-pressure chamber inside the joint, and the high-pressure chamber that connects the suction port and discharge valve on the surface that form the discharge valve and the discharge port. In the power transmission joint for transmitting torque according to the rotational speed difference between the both shafts, the valve body is provided with two orifices as the flow resistance generating means, and at least one orifice and a high pressure A spool-shaped switching valve that controls the electrical connection with the chamber is provided, and the cam housing or a member integrally fixed thereto has a positional relationship with the valve body. Hydraulic power transmission joint, characterized in that a cam surface for controlling the operation of the switching valve I. 2. The hydraulic type according to claim 1, wherein the spool-shaped switching valve is provided with a pressure receiving surface for receiving the pressure of the discharge oil, and the switching valve itself is pressed against the cam surface by a hydraulic reaction force thereof. Power transmission joint.