JPH0754868A - Hydraulic power transmission joint - Google Patents

Abstract

PURPOSE:To provide a hydraulic power transmission joint which performs locking only when differential movement of the joint used for distribution of driving power of a vehicle, is in the normal direction, can be used for shaft penetrating joint, has stable locking characteristics and torque characteristic, has a simple structure, and is inexpansively manufactured. CONSTITUTION:Friction torque is telected acting on a valve body 11 due to sliding contact with a rotor 5, and load transducing mechanisms 11, 16, 17 transduce the friction torque to load only in the case that relative rotational direction of shafts is performed in one direction. A closure valve 24 which closes a fluid resistance generation means 22 receiving pressure from the load transducing mechanisms 11, 16, 17. A spring member energizes the load transducing mechanisms 11, 16, 17 with a specified load in a direction opposite to the closure valve 24.

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, in Japanese Patent Application No. 1-175051, a hydraulic power transmission joint in which a hydraulic lock works only when the differential direction of the joint is forward. That is,
The hydraulic power transmission joint generates flow resistance in a hydraulic pump driven by a rotational speed difference between a first rotatable member and a second rotatable member that are relatively rotatable, and a discharge passage of the hydraulic pump. Means for providing the first and second flow resistances
In a hydraulic power transmission joint in which the transmission torque between the second rotating members is controlled, the collecting means for collecting the discharge fluid in one collecting chamber and the orifice closed when the pressure in the collecting chamber exceeds a predetermined value. And a discrimination control means for discriminating the relative rotation directions of the first and second rotating members to control the orifice closing operation of the variable orifice mechanism. A brake ring with a pin that receives the frictional force of the rotating member, and a stopper member that has a hole that is slidably provided on the other rotating member by the pin of the brake ring and into which the end of the variable orifice mechanism can be inserted. It was made to become.

[0003]

However, such a conventional hydraulic power transmission joint has the following problems. (1) Since the oil pressure detection unit is located at the center of the shaft of the joint, it cannot be used for a shaft-through type joint. (2) Since not only the discharge pressure but also the viscous resistance itself acts on the hydraulic pressure detection unit, when the viscosity of the oil changes due to temperature, the hydraulic pressure to be locked changes. Therefore, the lock characteristic becomes unstable. (3) The mechanism is complicated and the cost is high. (4) Since there is a leak in the oil pressure detection unit, the torque characteristic also becomes unstable depending on the temperature.

The present invention has been made in view of the above-mentioned conventional problems, and can be locked only when the differential direction of the joint is forward, and can be used for a shaft-penetrating joint. It is an object of the present invention to provide a hydraulic power transmission joint that can be manufactured, has stable lock characteristics and torque characteristics, has a simple configuration, and is inexpensive.

[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 a plurality of peaks on the inner side surface, and a cam housing connected to the other shaft and rotatably housed in the cam housing, and on one side surface. A rotor that forms a plurality of plunger chambers that open, and each of the plurality of plunger chambers,
A plurality of plungers, which are housed so as to be reciprocally movable under the pressure of a return spring and driven by the cam housing according to the relative rotation of the both shafts, and other end surfaces of the rotor that do not house the plungers. The suction and discharge holes that are open and are in sliding contact with the end surface of the rotor and the suction and discharge holes that communicate with the plunger chamber are positioned in a predetermined relationship with the cam housing, and suction is performed by the positional relationship with the suction and discharge holes. A valve, a valve body having a plurality of suction ports acting as a discharge valve and a discharge port formed on the surface thereof, and a collecting chamber provided inside the valve body for collecting discharge oil from the discharge port; A hydraulic power transmission joint for transmitting torque according to a rotational speed difference between the two shafts; A load conversion mechanism that detects a friction torque acting on the valve element by sliding contact and converts the friction torque into a load only when the relative rotation directions of the both shafts are one direction, and receives the pressure from the load conversion mechanism to cause the flow. It is characterized by comprising a closing valve for closing the resistance generating means and a spring member for urging the load conversion mechanism in a direction opposite to the closing valve with a predetermined load.

Further, the present invention is characterized in that the orifice as the flow resistance generating means is formed laterally on the protrusion of the valve body. Further, the present invention is characterized in that the shutoff valve is arranged concentrically with the flow resistance generating means so as to be movable in the axial direction, and is made of a rod-shaped member having a spherical end or a tapered end.

Further, the present invention is characterized in that the spring member has a plate portion for pushing the closing valve, and when a friction torque stronger than a spring force acts, the closing valve is pushed and locked. .

[0008]

According to the hydraulic power transmission joint of the present invention having such a structure, when the friction torque acting on the valve element due to the sliding contact with the rotor exceeds the spring force of the spring member only during forward rotation, The load is converted into a load, and the closing valve is pressed by the spring member so that it is in a locked state. At the time of reverse rotation, the spring member receives a load in the direction that does not lock, so that the closing valve is not pressed and does not lock. In a vehicle equipped with this joint on the front wheels, the tight corner braking phenomenon can be prevented without locking during tight corner turns, while high torque is generated on low μ roads such as sand. It can be locked securely and the running performance can be improved.

Further, unlike the conventional case, since the oil pressure detecting portion is not arranged at the shaft center portion, it can be used for a shaft penetrating joint. Further, since there is no oil pressure detecting portion and the closing valve is pressed and locked when the friction torque exceeds the spring force of the spring member, the locking torque does not change and the locking characteristic is stable.

Further, since there is no oil pressure detecting portion and there is no leak, the torque characteristic is stable. Further, since the oil pressure detecting section and the like are unnecessary, the structure is simple and the cost is low.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 11 are views showing an embodiment of the present invention. First, the structure will be described. In FIG. 1, reference numeral 1 denotes a cam having a cam surface 2 having two or more ridges on its inner surface. The cam 1 is connected to an output shaft (not shown) and rotates integrally with the output shaft. To do. The cam 1 is fixed to the cam housing 4 by the welded portion 3, and the cam housing 4 rotates integrally with the cam 1.

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 / discharge holes 10 so as to communicate with the respective plunger chambers 7.

Reference numeral 11 denotes 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. Further, a lid member 16 is provided in close contact with the back surface. 2 to 4 show the positional relationship between the cam housing 4 and the rotary valve 11.

2 to 4, a plurality of protrusions 17 are formed on the inner circumference of the cam housing 4 in the circumferential direction.
A notch 18 is formed between 7 and 7. The rotary valve 11 has a positioning projection 19 that engages with the notch 18 of the cam housing 4. Rotary valve 11
A collection chamber 20 as a high-pressure chamber is formed on the protrusion 19 of the projection 19, and the collection chamber 20 communicates with each discharge port 14. The collecting chamber 20 is closed by a closing member 21, and an orifice 22 as a flow resistance generating means is formed laterally at the outlet of the collecting chamber 20. The projection 19 on the outlet side of the orifice 22 is formed with a discharge oil passage 23 through which the oil that has passed through the orifice 22 is discharged to the low pressure chamber in the joint.

Further, the projection 19 is coaxial with the orifice 22.
Is provided with a lock valve 24 as a closing valve so as to be movable in the axial direction, and the lock valve 24 is formed of a rod-shaped member having a spherical end or a tapered end. When the lock valve 24 is pushed from the outside, the tip of the lock valve 24 blocks the orifice 22 and the joint is locked. FIG. 5 shows a spring member 25 that presses the lock valve 24 from the outside.

In FIG. 5, reference numeral 26 is a plate portion for pressing the lock valve 24, and 27 is a stopper portion for positioning the plate portion 26 in the returning direction. The plate portion 26 and the stopper portion 27 are connected to each other. It is connected to the part 28. A curved portion 29 extends on the plate portion 26,
A pin hole 30 is formed at the end of the curved portion 29. The plate portion 26, the stopper portion 27, and the connecting portion 28 are arranged so as to surround the protrusion 19, and the bending portion 29 is provided along the outer peripheral portion of the rotary valve 11, and the bending portion 29.
The end of is fixed to the rotary valve 11 by a pin 31. The plate portion 26 and the stopper portion 27 are constantly urged by a spring force in a direction in which the lock valve 24 is not pushed.

The friction torque acting on the rotary valve 11 is basically proportional to the transmission torque T of the joint. At the time of forward rotation of the rotary valve 11 in the direction shown by the arrow A in FIG.
When the plate portion 26 hits the plate 26, the lock valve 24 is pushed by a force proportional to the friction torque. However, when the spring force of the spring member 25 is stronger than the friction torque, the lock valve 24 is attached in the direction of opening the orifice 22. The normal torque characteristic is achieved.

Further, as shown in FIG. 3, when the friction torque exceeds the spring force of the spring member 25 at the time of normal rotation, the lock valve 24 is pressed and the orifice 22 is opened.
Close. This results in a lock characteristic. On the other hand, at the time of reverse rotation in which the rotary valve 11 rotates in the direction indicated by the arrow B in FIG. 4, the plate portion 26 does not push the lock valve 24, and always has the normal torque characteristic.

Rotary valve 11, cam housing 4
The protrusion 17 and the lid member 16 constitute a load converting mechanism as a whole, and the load converting mechanism detects the friction torque acting on the rotary valve 11 and locks the friction torque only when the rotation direction is the forward rotation direction. Valve 2
Convert to load for closing 4. That is, when the friction torque that presses the lock valve 24 becomes stronger than the spring force of the spring member 25, the joint is locked.

Referring again to FIG. 1, the rotary valve 11
Constitutes a timing member that determines the opening / closing timing of the suction / discharge hole 10, and the notch 18 and the protrusion 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 intake stroke, the intake port 12 of the rotary valve 11 and the rotor 5 are
Therefore, the oil can be sucked into the plunger chamber 7 through the orifice 22, the discharge oil passage 23, the suction passage 13, the suction port 12, and the suction discharge hole 10 of the rotor 5.

When the plunger 8 is in the discharge stroke, the suction stroke is reversed, and the suction / discharge hole 10 of the rotor 5 communicates with the collecting chamber 20 through the discharge port 14 of the rotary valve 11. A retainer 32 rotates integrally with the cam housing 4, and the retainer 32 supports the input shaft 6 via a bearing 33. The thrust needle bearing 3 is provided between the retainer 32 and the rotary valve 11 via the lid member 16 and the quenching plate 34.
5, the friction torque on the thrust needle bearing 35 side is the rotor 5 and the rotary valve 1.
It is set so as to be smaller than the friction torque during the period 1. Therefore, when the direction of differential rotation changes,
The rotary valve 11 rotates with the rotor 5,
The positioning projection 19 of the rotary valve 11 rotates until it contacts the notch 18 of the cam housing 4, and then rotates together with the cam housing 4. As a result, the intake / discharge hole 10 is forcibly opened / closed at a predetermined timing even during normal rotation or reverse rotation.

A cover 3 is provided between the retainer 32 and the input shaft 6.
6 is provided inside the cover 36, and the retainer 3
An oil seal 37 is interposed between 2 and the input shaft 6. The oil seal 37 prevents oil from leaking outside the joint. Reference numerals 38 and 39 denote communication passages formed in the input shaft 6, and the inside of the joint and the accumulator chamber 40 communicate with each other through the communication passages 38 and 39. Accumulator room 4
In 0, the accumulator piston 41 is movably accommodated, and the accumulator piston 41 moves according to the internal pressure of the joint. That is, the accumulator piston 41 absorbs the thermal expansion of the oil filled in the joint.

Reference numeral 42 denotes a lid provided on the input shaft 6, and the lid 42 also has a function as a stopper of the accumulator piston 41. Air 43 is enclosed in the accumulator piston 41. In addition, 44 is an oiling hole, 45 is a screw hole, 46 is a needle bearing, 47 and 48 are stopper rings, and 49 and 50 are O-rings.

Next, the operation will be described. Cam 1 and rotor 5
When there is no difference in rotation between and, 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, when a rotation difference occurs between the cam 1 and the rotor 5, the plunger 8 in the discharge stroke is pushed axially by the cam surface 2 of the cam 1.

At this time, the suction / discharge hole 10 is formed in the discharge port 14
Plunger 8 is connected to plunger room 7
Oil is pushed out from the suction / discharge hole 10 to the discharge port 14 of the rotary valve 11. The oil pushed out to the discharge port 14 is supplied from the discharge oil passage 23 to the suction passage 13 through the communication groove 15, the collecting chamber 20, and the orifice 22. At this time,
Due to the resistance of the orifice 22, the communication groove 15, the collecting chamber 20,
The hydraulic pressure in the discharge port 14 and the plunger chamber 7 rises, 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 ports 14 communicate with each other in the collecting chamber 20, the hydraulic pressures of all the plunger chambers 7 in the discharge process are equal.

Further, when the cam 1 rotates, the 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 sucked into the plunger chamber 7 through the suction port 12 and the suction / discharge hole 10, and the plunger 8 returns along the cam surface 2 of the cam 1. FIG. 6 shows the state of the lock valve 24 when the normal rotation is not locked.

In FIG. 6, the rotary valve 11 is
The friction torque from the rotor 5 is received in the direction indicated by the arrow A, and the reaction force is applied to the protrusion 17 of the cam housing 4.
Acts on the plate portion 26 in the direction to close the lock valve 24. A biasing force from the spring member 25 acts on the plate portion 26 in a direction in which the lock valve 24 is not pushed, and the stopper portion 27 positions the plate portion 26 with respect to the projection 19 of the rotary valve 11.

In this case, since the spring force of the spring member 25 is stronger than the friction torque, the lock valve 24 does not close the orifice 22. Therefore, the torque characteristic shown in C of FIG. 7 is exhibited. That is, when the forward rotation is not locked, the torque characteristic C is proportional to the square of the rotation speed difference ΔN.

Next, when a high torque is generated on a low μ road such as sand, the friction torque acting on the rotary valve 11 increases, and when the spring force of the spring member 25 is exceeded, as shown in FIGS. 8 and 9. The lock valve 24 closes the orifice 22. As shown by an arrow D in FIG. 8, oil from the plunger chamber 7 is sucked and discharged through the suction port 10 and the discharge port 1.
4 and then gather in the gathering chamber 20, but the orifice 22
Cannot be passed through the orifice 22 because the valve is closed by the lock valve 24. In this way, it becomes a locked state. The arrow E indicates the rotation direction (normal rotation).

That is, as shown in FIG. 9, when the friction torque exceeds the spring force of the spring member 25 due to the high differential rotation of the joint, the lock valve 24 is pressed by the plate portion 26 to close the orifice 22. During such a forward rotation lock, the torque characteristic shifts from point F in FIG. 7 to G and becomes the lock characteristic.

Next, FIG. 10 shows the flow of oil when the joint is rotated in the reverse direction. In FIG. 10, an arrow H indicates that the rotation direction of the rotor 5 has been reversed. During this reverse rotation, the oil in the plunger chamber 7 of the plunger 8 due to the discharge stroke passes through the suction / discharge hole 10, the discharge port 14, the collecting chamber 20 and the orifice 22. The torque characteristic at the time of reverse rotation is a characteristic proportional to the square of the rotational speed difference ΔN.

During this reverse rotation, the lock valve 24 does not operate and the orifice 22 is open. That is, FIG.
As shown in FIG. 4, when the motor is rotated in the reverse direction, the rotary valve 11 rotates in the direction indicated by the arrow B, the protrusion 19 moves in the direction indicated by the arrow B along the notch 18 of the cam housing 4, and the stopper portion 27 is moved. It hits the protrusion 17 of the cam housing 4 by sandwiching it.

The friction torque urges the lock valve 24 in a direction in which it is not pushed, and the spring member 25 also urges the lock valve 24 in a direction in which it is not pushed. Therefore, the lock valve 24 does not operate and the orifice 22 remains open. In this way, since the lock is prevented during the reverse rotation, as shown in FIG. 12, in the vehicle on the front wheel 51 side and in which the main joint 53 is mounted near the front wheel side differential device 52,
In the normal forward driving state, the tight corner braking phenomenon can be prevented from occurring without locking during the tight corner turning.

In FIG. 12, 54 is an engine, 55 is a transmission, 56 is a transfer, 57 is a rear wheel, 58 is a rear wheel side differential device, 59 is a rear wheel side propeller shaft, and 60 is a front wheel side propeller shaft. . Also, when moving forward, if high torque is generated on a low μ road such as sandy land, it can be securely locked,
The running performance can be improved.

Further, since the lock valve 24 and the like are not arranged at the central portion of the shaft of the joint, the joint can be used for the shaft penetrating joint. Further, the conventional hydraulic pressure detecting portion is not required, the plate portion 26 is applied to the protrusion 17 of the cam housing 4, the lock valve 24 is pushed by a force proportional to the friction torque, and the friction torque becomes stronger than the spring force of the spring member 25. Since it is locked at the time of locking and not locked at the time of reverse rotation, the locking torque does not change, and stable locking characteristics can be obtained.

Further, since the oil pressure detecting portion is not required, the oil pressure detecting portion does not leak and the torque characteristic can be stabilized. Further, since the oil pressure detecting unit is not necessary, the structure is simple and the cost is low.

[0037]

As described above, according to the present invention, when the friction torque acting on the valve element exceeds the spring force of the spring member at the time of forward rotation, the stop valve is closed and locked to reverse rotation. Since it is not locked at times, it does not lock during tight corner turning in vehicles equipped with this joint on the front wheels, preventing the occurrence of tight corner braking phenomenon, and locking on low μ roads such as sandy land and running performance Can be improved.

Further, since the oil pressure detecting portion is not located at the center of the shaft, it can be used for a shaft penetrating joint, and since the oil pressure for locking does not change, the lock characteristic can be stabilized, and
Since there is no leak, the torque characteristic can be stabilized. Further, the structure is simple and the cost is low.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a state in which a normal rotation is unlocked.

FIG. 3 is a diagram showing a state when the forward rotation is locked.

FIG. 4 is a diagram showing a state at the time of reverse rotation.

FIG. 5 is a perspective view of a spring member.

FIG. 6 is an operation explanatory diagram when the forward rotation is not locked.

FIG. 7 is a graph showing torque characteristics.

FIG. 8 is a diagram showing an oil flow when the forward rotation is locked.

FIG. 9 is an explanatory diagram of the operation when the forward rotation is locked.

FIG. 10 is a diagram showing the flow of oil during reverse rotation.

FIG. 11 is an explanatory diagram of operation during reverse rotation.

FIG. 12 is a diagram showing an arrangement of joints.

[Explanation of symbols]

 1: Cam 2: Cam surface 3: Welded part 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, 19: Protrusion 18: Notch 20: Collecting chamber 21: Closing member 22: Orifice (flow resistance generating means) 23: Discharge oil passage 24 : Lock valve (close valve) 25: Spring member 26: Plate part 27: Stopper part 28: Connecting part 29: Curved part 30: Pin hole 31: Pin 32: Retainer 33: Bearing 34: Quenching plate 35: Thrust needle bearing 36 : Cover 37: Oil seal 38, 39: Communication passage 40: Accumulator chamber 41: Accumulator piston 4 : Lid 43: Air 44: Oiling hole 45: Screw hole 46: Needle bearing 47, 48: Stopper ring 49, 50: O-ring 51: Front wheel 52: Front wheel side differential device 53: Joint 54: Engine 55: Transmission 56: Transfer 57: Rear Wheel 58: Rear Wheel Differential Device 59: Rear Wheel Propeller Shaft 60: Front Wheel Propeller Shaft

Claims (4)

[Claims] 1. A cam housing provided between relatively rotatable input / output shafts, connected to said one shaft, and having a cam surface having a plurality of peaks on its inner side surface, and to said other shaft. And a rotor having a plurality of plunger chambers rotatably housed in the cam housing and having an opening on one side surface, and the plunger chambers are reciprocally movable under the pressure of a return spring. Stored in
A plurality of plungers driven by the cam housing according to the relative rotation of the two shafts; a suction / discharge hole that opens to the other end surface of the rotor that does not house the plunger and communicates with the plunger chamber; Is rotatably slidably contacted with the end surface of the intake port, is positioned in a predetermined relationship with the cam housing, and has a plurality of intake ports that act as intake valves and discharge valves depending on the positional relationship with the intake and discharge holes. A valve body formed on the surface; a collecting chamber provided inside the valve body for collecting the oil discharged from the discharge port; and means for generating flow resistance at the outlet of the collecting chamber; In a hydraulic power transmission joint that transmits torque according to the difference in rotational speed; frictional torque acting on the valve element by sliding contact with the rotor is detected, A load conversion mechanism that converts a load only when the relative rotation direction of the shaft is one direction, a closing valve that closes the flow resistance generating means by receiving pressure from the load conversion mechanism, and a closing mechanism that closes the load conversion mechanism. A hydraulic power transmission joint comprising a spring member for urging a predetermined load in a direction opposite to the valve. 2. The hydraulic power transmission joint according to claim 1, wherein an orifice as the flow resistance generating means is formed laterally on the protrusion of the valve body. 3. The shut-off valve is arranged concentrically with the flow resistance generating means so as to be movable in the axial direction, and is made of a rod-shaped member having a spherical end or a tapered end.
Hydraulic power transmission joint. 4. The spring member has a plate portion for pushing the closing valve, and when the friction torque stronger than the spring force acts, the closing valve is pressed and locked. Hydraulic power transmission joint.