JPH10110747A - Hydraulic type power transmission coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering of torque due to leak of oil and to prevent the occurrence of malfunction of a part owing to choking with contaminants. SOLUTION: A hydraulic type power transmission coupling comprises a containing hole 61 formed by expanding a delivery port 14; a drain hole 65 to intercommunicate the containing hole 61 and the low pressure chamber 54 side; a ball 66 contained in the containing hole 61 and closing the drain hole 65; and a weight member movably contained in the containing hole 61 and moved by a centrifugal force when a car speed attains a specified value and pressing the ball 66 for movement and opening the drain hole.

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 driving force distribution of a vehicle, and more particularly to a hydraulic power transmission coupling for cutting a torque at a predetermined vehicle speed.

[0002]

2. Description of the Related Art Conventional hydraulic power transmission couplings include, for example, the following. The hydraulic power transmission coupling is provided between a relatively rotatable input / output shaft, is connected to the one shaft, and has a cam housing having a cam surface having two or more peaks on an inner surface; A rotor connected to a shaft and rotatably housed in the cam housing and having a plurality of plunger chambers formed in the axial direction; reciprocating each of the plurality of plunger chambers under the pressure of a return spring A plurality of plungers housed movably and driven by the cam surface when the shafts rotate relative to each other; a suction / discharge hole formed in the rotor and communicating with the plunger chamber; The suction valve is rotatably slid and is positioned in a predetermined relationship with the cam housing. The operation of the suction valve and the discharge valve depends on the positional relationship with the suction / discharge hole. A rotary valve having a plurality of suction ports and discharge ports formed on the surface thereof, and flow resistance generating means for generating flow resistance by the flow of discharge oil by driving the plunger; Transmits torque.

In such a hydraulic power transmission coupling,
If different diameter tires are attached to the front and rear shafts, the differential rotation speed increases with the increase in vehicle speed, the torque increases, and if the differential between the front and rear of the vehicle is full of torque, the differential will overheat and damage will occur. Would. In order to solve such a problem, a type has been proposed in which a spool that moves in accordance with the vehicle speed (centrifugal force) is provided in a rotary valve to cut torque (see FIGS. 9 to 11). ).

FIG. 9 is a partial front view of a rotary valve of a hydraulic power transmission joint, FIG. 10 is a partial sectional view of the rotary valve illustrating an initial state, and FIG. 11 is a portion of the rotary valve illustrating an oil flow during operation. It is sectional drawing. 9 to 11
In the figure, reference numeral 101 denotes a rotary valve of a hydraulic power transmission joint. A discharge port 102 is formed on a front surface of the rotary valve 101, and the discharge port 102 communicates with a communication groove 103 formed on a back surface of the rotary valve 101. . A suction port and a suction path (not shown) are formed on the surface of the rotary valve 101.

A projection 104 is formed on the outer periphery of the rotary valve 101, and the projection 104 engages with a notch formed in a cam housing (not shown).
Arrow A indicates the direction of rotation of rotary valve 101. A storage hole 105 is formed in the rotary valve 101 from the outer periphery toward the discharge port 102, and a roll pin 106 is provided at an opening of the storage hole 105. A spool valve 107 is slidably accommodated in the accommodation hole 105 in the radial direction (centrifugal direction).

The spool valve 107 has a first valve body 107.
A, a second valve body 107B, and a shaft portion 107C connecting the first valve body 107A and the second valve body 107B. The first valve body 107A and the second valve body 107B An inflow chamber 108 into which the oil flows is formed between them.
A spring 109 for urging the spool valve 107 with a spring force indicated by an arrow P is interposed between the second valve body 107B of the spool valve 107 and the roll pin 106. On the other hand, a centrifugal force as shown by an arrow F acts on the spool valve 107.

An inflow chamber 1 is provided on the surface of the rotary valve 101.
08 and an inflow hole 110 communicating with the inflow hole 110 is formed.
Is a communication passage 111 formed on the surface of the rotary valve 101.
Through the discharge port 102. Therefore, as shown in FIG. 10, the high-pressure oil in the discharge port 102 passes through the communication passage 111 and the inflow hole 110, and the inflow chamber 1
08.

Further, a drain hole 112 is formed on the back surface of the rotary valve 101, and the drain hole 112 is formed as shown in FIG.
As shown in FIG.
7 is closed by the second valve body 107B. FIG.
When the spool valve 107 moves in the centrifugal direction due to the centrifugal force as shown in FIG.
Opened by 07B. Also, the rotary valve 101
The pressure release hole 11 is provided on the back surface below the drain hole 112 of FIG.
3 are formed, and the pressure release hole 113 communicates with the storage hole 105.

In the initial state where the vehicle speed is low and the centrifugal force is low, as shown in FIG.
Since the spring force P of the spring 109 is larger than the centrifugal force F acting on the spool valve 107, the spool valve 107 does not move in the centrifugal direction, so the drain hole 112 is closed.
Therefore, the oil from the discharge port 102 flows into the inflow chamber 108 through the communication passage 111 and the inflow hole 110, but is not drained from the drain hole 112 to the low pressure chamber side. In this initial situation, normal torque characteristics are obtained.

When the vehicle speed exceeds a predetermined value and the centrifugal force F exceeds a predetermined value, as shown in FIG.
Centrifugal force F applied to the spring 109 is the spring force P of the spring 109
As the spool valve 107 becomes larger, the spool valve 107 moves in the direction shown by arrow B to open the drain hole 112. Therefore, high-pressure oil in the discharge port 102 enters the inflow chamber 108 through the communication passage 111 and the inflow hole 110 as shown by the arrow C, and drains from the drain hole 112. Thus, torque cut is performed.

[0011]

However, in such a conventional hydraulic power transmission coupling, the clearance between the spool and the storage hole is narrowed to prevent oil leakage from the high pressure chamber and to reduce the torque. In order to avoid a decrease in the size, there is a problem that a spool operation failure occurs due to contamination clogging.

If the clearance between the spool and the storage hole is widened to avoid malfunction of the spool due to contamination clogging, there has been a problem that torque is reduced due to oil leak from the high pressure chamber. The present invention has been made in view of such conventional problems, and uses a ball valve instead of a spool valve to abolish the seal in the clearance, avoid operation failure due to contamination clogging, and reduce An object of the present invention is to provide a hydraulic power transmission coupling capable of preventing a decrease in torque due to leakage.

[0013]

In order to achieve the above object, the present invention is configured as follows. First, the present invention provides a cam housing provided between input / output shafts which are relatively rotatable and connected to one shaft and having a cam surface having two or more ridges on an inner surface; and connected to the other shaft. And a rotor rotatably housed in the cam housing and having a plurality of plunger chambers formed in the axial direction; housed in each of the plurality of plunger chambers so as to be reciprocally movable under the pressure of the return spring. A plurality of plungers driven by a cam surface when the two shafts rotate relative to each other; a suction and discharge hole formed in the rotor and communicating with the plunger chamber;
A plurality of suction ports and discharge ports, which are rotatably slidably in contact with the end face of the rotor, are positioned in a predetermined relationship with the cam housing, and act as a suction valve and a discharge valve depending on the positional relationship with the suction and discharge holes. And a flow resistance generating means for generating flow resistance by the flow of discharge oil by driving a plunger; for a hydraulic power transmission coupling for transmitting a torque corresponding to a rotational speed difference between both shafts. I do.

The present invention is directed to such a hydraulic power transmission joint, wherein a storage hole formed by expanding a discharge port, a drain hole communicating the storage hole with the low pressure chamber side, and a drain stored in the storage hole are provided. A ball that closes the hole, and a weight member that is movably stored in the storage hole and moves by centrifugal force when the vehicle speed reaches a constant value to press and move the ball to open the drain hole.

The weight member may be formed with a tapered surface for pressing and moving the ball with a moment force. In this case, when the vehicle speed reaches a constant value, the ball is moved in balance with the moment force. The weight member may have a ball storage groove for storing a ball. In this case, when the vehicle speed becomes a constant value, the weight member moves by the centrifugal force and moves the ball directly.

Further, a cam surface may be formed at one end of the weight member, and a flat portion for pressing the ball may be formed at the other end. In this case, when the vehicle speed becomes a constant value, the weight member moves in the centrifugal direction and a predetermined circumferential direction by the centrifugal force, and moves the ball on the flat portion. At the time of sudden deceleration, the weight member moves in a predetermined circumferential direction, and moves the ball on a flat portion. At the time of sudden start, the weight member tries to move in the opposite circumferential direction, but does not move by contacting the wall surface of the storage hole.

If the weight member has a tapered surface or a ball storage groove, a spring storage hole is formed in the weight member, and a spring for biasing the weight member toward the center of the rotary valve is stored in the spring storage hole. I do. When the cam surface and the flat portion are formed on the weight member, the first spring storage hole and the second spring storage hole are formed on the weight member.
The first spring for urging the weight member toward the center of the rotary valve is housed in the second spring housing hole, and the weight member is provided in the second spring housing hole in a predetermined manner. The second spring that urges in the circumferential direction is housed.

According to the hydraulic power transmission joint of the present invention having such a configuration, since the ball closes the drain hole until the centrifugal force reaches a constant value, a decrease in torque due to oil leak is prevented. can do. In addition, since the discharge port is expanded to form a storage hole and the weight member, spring and ball are stored in the storage hole, the gap between each part can be made large, so that operation failure of each part due to contamination clogging. Can be avoided.

Further, when the ball is moved with the balance of the moment force when the centrifugal force is constant, the force for moving the ball is small. Furthermore, it is possible to perform torque cut by moving the ball even in the case of sudden deceleration of the rotation of the joint itself, and to prevent torque cut without moving the ball at the time of sudden start, for example, ABS (anti-lock brake system) In a 4WD vehicle equipped with, torque interference between the front and rear wheels can be turned off during ABS operation (rapid deceleration of the joint rotation), and the adaptability to the ABS is excellent.

[0020]

FIG. 1 is a sectional view showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cam having a cam surface 2 having two or more peaks on an inner surface thereof. The cam 1 is connected to an output shaft (not shown) and rotates integrally with the output shaft.
Further, the cam 1 is fixed to the cam housing 4 at the welding portion 3, and the cam 1 rotates integrally with the cam housing 4.

Reference numeral 5 denotes a rotor rotatably housed in the cam housing 4. The rotor 5 is connected to an input shaft 6,
It rotates integrally with the input shaft 6. A plurality of plunger chambers 7 are formed in the rotor 5 in the axial direction.
Inside, a plurality of plungers 8 are slidably accommodated via return springs 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 suction port 12 and a suction passage 13 on the surface.
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, and the communication groove 15 is closed. The rotary valve 11 has a positioning projection 18 that engages with a notch 17 formed on the inner periphery of the cam housing 4.

The rotary valve 11 constitutes a timing member for determining the opening / closing timing of the suction / discharge port 10, and the notch 17 and the projection 18 constitute a positioning mechanism for regulating the phase relationship between the cam 1 and the rotary valve 11. . When the plunger 8 is in the suction stroke, the rotary valve 11
And the suction port 12 of the rotor 5 and the suction / discharge port 10 of the rotor 5 communicate with each other.
2, through the suction passage 13, through the suction and discharge holes 10 of the rotor 5,
Oil can be sucked into the plunger chamber 7.

When the plunger 8 is in the discharge stroke, the relationship is opposite to that of the suction stroke, and the suction and discharge holes 10 of the rotor 5 communicate with the communication groove 15 via the discharge port 14 of the rotary valve 11. Reference numeral 19 denotes a bearing retainer which rotates integrally with the cam housing 4, and a bearing 20.
, The input shaft 6 is supported. A thrust needle bearing 21 is interposed between the bearing retainer 19 and the rotary valve 11, and the friction torque on the thrust needle bearing 21 side is set to be smaller than the friction torque between the rotor 5 and the rotary valve 11. I have.

Therefore, when the direction of the differential rotation changes,
The rotary valve 11 rotates together with the rotor 5, rotates until the positioning projection 18 of the rotary valve 11 hits the notch 17 of the cam housing 4, and then rotates together with the cam housing 4. As a result, the suction / discharge port 10 is forcibly switched at a predetermined timing even at the time of forward rotation or reverse rotation.

An oil seal 22 is provided between the bearing retainer 19 and the input shaft 6, and an accumulator piston 23 for absorbing thermal expansion and contraction of oil is slidably housed inside the input shaft 6. Have been. Reference numeral 24 denotes a lid member for preventing muddy water from entering the O-ring sliding portion of the accumulator chamber 25. The accumulator chamber 25 is connected to the oil passage 2
It communicates with the inside of the joint via 6, 27. The rotary valve 11 has a high pressure chamber 2 communicating with the discharge port 14.
8 is formed, and the outlet of the high-pressure chamber 28 is closed by a plug 29. Reference numeral 30 denotes a lubrication hole, 31 denotes a needle bearing, 32 denotes a screw hole, 33 and 34 denote O-rings,
5 and 36 are snap rings, and 37 is a mounting hole.

FIG. 2 is a sectional view of a main part. In FIG.
Reference numeral 4 denotes a cam housing, in which a rotary valve 11 is rotatably housed. A projection 18 is formed integrally with the rotary valve 11, and a cutout 17 with which the projection 18 is engaged is formed in the cam housing 4.

A discharge port 14 and a suction port 12 are formed alternately in the circumferential direction on the surface of the rotary valve 11, and a suction passage 13 is formed in communication with the suction port 12. The suction passage 13 extends to the outer periphery of the rotary valve 11. A low-pressure chamber 54 is formed between the rotary valve 11 and the cam housing 4. A high-pressure chamber 28 is formed in the rotary valve 11 and communicates with the discharge port 14 through a through-hole 38. A hardened collar member 39 is housed in the high-pressure chamber 28, and a plug 29 is screwed to the plug 29 following the collar member 39. Have been.

A storage chamber 41 in which a ball 40 as a valve body is movably stored is formed in the collar member 39. The storage chamber 41 communicates with the communication hole 38 via the opening 42 and communicates with the communication hole 44 via the opening 43. The communication hole 44 communicates with a storage hole 46 that stores the pin member 45, and the pin member 45 is slidably stored in the storage hole 46. The pin member 45 has a small diameter pin portion 47 and a large diameter base end portion 48, and the position of the ball 40 is controlled by the pin member 45.

The gap between the pin portion 47 and the communication hole 44 is
An orifice 49 is provided as flow resistance generating means. Therefore, the hole diameter of the communication hole 44 can be formed large, and the hole diameter accuracy can be made rough. When the ball 40 is held by the pin member 45, the orifice 49 is open, but when the ball 40 is free, the ball 40 sits on the valve seat 50 formed in the opening 43 of the collar member 39. The orifice 49 is closed.

The pin member 45 accommodated in the accommodating hole 46 is urged by a spring 51 to hold the ball 40, and when the oil pressure in the accommodating chamber 41 accommodating the ball 40 rises to a predetermined value or more, the pin member 45 The member 45 is a spring 51
And moves rightward against the roll pin 52.
The roll pin 52 prevents the pin member 45 from moving over a certain distance. Reference numeral 53 denotes a low pressure hole communicating with the low pressure side.

Here, a storage hole 61 is formed by enlarging the inside of the discharge port 14, and a weight member 62 is movably stored in the storage hole 61. A spring receiving hole 63 is formed in the weight member 62, a spring 64 is stored in the receiving hole 63, and the spring 64 is
2 is urged toward the center of the rotary valve 11.

The storage hole 61 and the low-pressure chamber 54 have a drain hole 65.
The drain hole 65 is constituted by a large diameter portion 65A and a small diameter portion 65B communicating with the large diameter portion 65A, and the small diameter portion 65B has a predetermined opening area. The drain hole 65 is closed by a ball 66 by hydraulic pressure, and is opened when no hydraulic pressure acts. The weight member 62 has a flat portion 6
2A is formed, and the tapered surface 62 continues to the flat portion 62A.
B is formed. The ball 66 is in contact with the tapered surface 62B.

Since the weight member 62 does not move in the centrifugal direction until the vehicle speed does not reach the constant value and the centrifugal force reaches the constant value, the ball 66 closes the drain hole 65 by hydraulic pressure. When the vehicle speed exceeds a certain value and the centrifugal force exceeds a certain value, the weight member 62 moves in the centrifugal direction against the spring force of the spring 64.
Reference numeral 2 denotes a tapered surface 62B for moving the ball 66 from the drain hole 65 by balancing moment force. When the ball 66 opens the drain hole 65, high-pressure oil is drained from the storage hole 61 through the drain hole 65 to the low-pressure chamber 54.

FIG. 3 is an explanatory view of the moment force acting on the ball 66. In FIG. 3, reference numeral 11 denotes a rotary valve, and a drain hole 65 is formed in the rotary valve 11. The drain hole 65 is normally closed by the ball 66, and the tapered surface 62B of the weight member 62 is in contact with the ball 66. A spring 64 is provided between the weight member 62 and the wall surface of the storage hole 61 formed to extend inside the discharge port 14, and the spring 64 urges the weight member 62 with a predetermined spring force.

F1 indicates the centrifugal force of the weight member 62,
F1 = m · r · w ² m is weight member 6
2, r represents the radius of the weight member 62 from the center, and w represents the rotational angular velocity. P1 is the spring force of the spring 64. T is the combined force of the centrifugal force and the spring force, and is represented by T = F1-P1. F
2 is a force acting on the ball 66, and F2 = T / sin
It is represented by θ. θ indicates the angle of the tapered surface 62B of the weight member 62. The balance of the moment force is expressed by the following equation.

ΜF2 · z + ΔP · A · x−F2 · y = 0 μ is the friction coefficient between the tapered surface 62B of the weight member 62 and the ball 66, z is the distance from the fulcrum S to the tapered surface 62B, and ΔP is the ball 66. Working hydraulic pressure, A is ball 66
, X indicates the distance from the fulcrum S to the center of the ball 66, and y indicates the distance from the fulcrum S to F2.

As shown in the above equation, when the moment force is balanced and is zero, the ball 66 closes the drain hole 65. When μF2 · z + ΔP · A · x <F2 · y, the ball 66 moves and the drain hole 65 opens. Next, the operation will be described. In FIG. 1, a cam 1 and a 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, since the suction / discharge port 10 communicates with the discharge port 14, the plunger 8 pushes the oil in the plunger chamber 7 from the suction / discharge port 10 to the discharge port 14 of the rotary valve 11.

The oil pushed out to the discharge port 14 is supplied from the suction passage 13 to the suction port 12 through the orifice. At this time, discharge port 1
4. The hydraulic pressure in the plunger chamber 7 rises, and a reaction force is generated in the plunger 8. By rotating the cam 1 against this plunger reaction force, torque is generated, and the cam 1
And the rotor 5 transmits torque. Since the discharge port 14 is communicated with the communication groove 15, the hydraulic pressure of all the plunger chambers 7 in the discharge stroke becomes equal.

Further, when the cam 1 rotates, a suction stroke occurs, and the suction / discharge port 10 communicates with the suction port 12.
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. Here, as shown in FIG. 4, when the generated transmission torque ΔT is 0, the vehicle speed V
Is greater than or equal to a fixed value V0, and when the centrifugal force F is also greater than or equal to a fixed value F0, a torque cut is performed.

That is, when the vehicle speed V exceeds the fixed value V0 and the centrifugal force F also exceeds the constant value F0, the centrifugal force F applied to the weight member 62 becomes larger than the spring force of the spring 64. Move in the direction. For this reason, the tapered surface 62B of the weight member 62
Moves the ball 66 by the moment force to open the drain hole 65.

That is, when the balance of the moment force is μ · F2 · Z + ΔP · A · x <F2 · y, the ball 66 opens the drain hole 65, and the high-pressure oil of the discharge port 14 passes through the drain hole 65. It is drained to the low pressure chamber 54. FIG. 5 shows the torque characteristics after the torque cut.

As shown in FIG. 5, the torque T increases according to the rotation difference rpm, but the magnitude can be freely set by the contact area A, and the transmitted torque T can be reduced. Therefore, no torque is accumulated in the front-rear differential of the vehicle, and the differential does not overheat, so that the differential is not damaged. On the other hand, in FIG.
Until it reaches zero, the centrifugal force F also does not reach the fixed value F0. Therefore, the spring force of the spring 64 is greater than the centrifugal force F applied to the weight member 62, and the weight member 62 does not move. Therefore, the ball 66 keeps the drain hole 65 closed, and no torque cut is performed.

FIG. 6 shows torque characteristics when such a torque cut is not performed. That is, the rotation difference r
When pm does not reach the predetermined value, the oil pressure is small, and the force of pushing the pin member 45 by the spring 51 is greater than the force of pushing the pin member 45 by the oil pressure in the storage chamber 41. Therefore, the ball 40 is held by the pin member 45. , The oil passes through the orifice 49.

Therefore, the torque characteristic at this time is a normal torque characteristic as shown in FIG. Next, when the rotation difference rpm exceeds a predetermined value, the hydraulic pressure of the storage chamber 41 increases, and the force of pressing the pin member 45 by the hydraulic pressure of the storage chamber 41 becomes larger than the force of pressing the pin member 45 by the spring 51. The member 45 moves to the right, the spring 51 contracts, and the ball 40 becomes free. The ball 40 sits on the valve seat 50 and closes the orifice 49.

The torque characteristic at this time is a lock characteristic as shown in FIG. As described above, until the centrifugal force F becomes equal to or more than the fixed value F0, the ball 66 closes the drain hole 65 by the hydraulic pressure, so that the torque does not decrease due to the oil leak. Further, the inside of the discharge port 14 is extended to form a storage hole 61, and the weight member 62, the spring 64, and the ball 66 are stored in the storage hole 61, so that the gaps between the components can be increased. As a result, component malfunction due to contamination clogging is eliminated.

When the centrifugal force F becomes equal to or more than the fixed value F0, the ball 66 is moved by the balance of the moment force, so that the force for moving the ball 66 is small. In FIG. 4, when the transmitted torque ΔT is zero, the vehicle speed V
Is a constant value V0, the torque cut is performed. However, when the torque ΔT transmitted at the predetermined oil pressure ΔP is larger by ΔT1, the torque cut is performed when the vehicle speed V is V0 + ΔV = V1.

FIG. 7 is a sectional view showing a main part of a second embodiment of the present invention. 7, reference numeral 71 denotes a rotary valve 1
The storage hole 71 is formed by expanding a part of the discharge port 14. A weight member 72 movable in the centrifugal direction is accommodated in the accommodation hole 71. That is, a spring housing hole 73 is formed in the weight member 72, and a spring 75 is interposed between a bottom wall of the spring housing hole 73 and a retainer 74 provided in the housing hole 73.

The spring 75 urges the weight member 72 toward the center of the rotary valve 11. Storage hole 7
1 and the suction port 12, a drain hole 76 is formed. The drain hole 76 communicates with the large diameter portion 76A opening to the suction port 12 and the large diameter portion 76A, and the small diameter portion 76B opening to the storage hole 71. It is composed of Drain hole 7
The small-diameter portion 76B has a predetermined opening area so that when the drain hole 76 is opened, a predetermined torque is obtained.

A ball housing groove 77 is formed in the weight member 72, and a ball 78 is housed in the ball housing groove 77. When the weight member 72 does not move, the ball 78 housed in the ball housing groove 77 closes the drain hole 76. When the weight member 72 moves, the ball 78 moves together and opens the drain hole 76. next,
The operation will be described.

As shown in FIG. 4, the centrifugal force F applied to the weight member 72 is smaller than the spring force of the spring 75 until the vehicle speed V reaches the centrifugal off vehicle speed V0.
The weight member 72 does not move in the centrifugal direction. Therefore, the ball 78 keeps the drain hole 76 closed.
Therefore, no torque cut is performed. FIG. 6 shows the torque characteristics when the torque is not cut.

When the vehicle speed V exceeds the centrifugal off vehicle speed V0, the centrifugal force F applied to the weight member 72 becomes larger than the spring force of the spring 75, so that the weight member 72 moves in the centrifugal direction and the ball 78 moves together. Therefore, the ball 78 opens the drain hole 76. The high-pressure oil in the discharge port 14 passes through the drain hole 76 and passes through the suction port 1.
After that, the fluid is drained to the suction passage 13 through which the torque is cut. The torque characteristics after such a torque cut are shown in FIG.

As described above, since the ball 78 closes the drain hole 76 by the oil pressure until the centrifugal force F becomes a constant value, a decrease in torque due to oil leak can be prevented. In addition, since the weight member 72, the spring 75, and the ball 78 are housed in the housing hole 71 formed by expanding the discharge port 14, a gap between each part can be increased, and malfunction of the part due to contamination clogging can be prevented. Can be avoided.

The weight member 72 has the ball storage groove 7.
Since the ball 78 is formed and the ball 78 is directly moved by the movement of the weight member 72, the structure is simplified as compared with the case where the ball 78 is moved by balancing the moment force. FIG.
FIG. 6 is a sectional view of a main part showing a third embodiment of the present invention. In FIG. 8, a storage hole 81 is formed by expanding the discharge port 14 in the storage hole 81. The bottom wall of the storage hole 81 on the center side of the rotary valve 11 is formed flat.

Further, one circumferential side wall of the storage hole 81 is
It is formed on a tapered surface, and a substantially flat surface portion is formed on the other side wall on the opposite side. A weight member 82 is accommodated in the accommodation hole 81 so as to be movable in the centrifugal direction and the circumferential direction. A cam surface 83 having an angle θ corresponding to the tapered surface of the storage hole 81 is formed in the weight member 82, a plane portion 84 is formed on the opposite side, and a first spring storage hole 85 is formed in the plane portion 84. Further, a tapered surface 86 is formed following the flat portion 84, and a flat portion 87 is formed following the tapered surface 86.

The weight member 82 has a flat portion 88 corresponding to the bottom wall of the storage hole 81, and a surface 89 having the same shape corresponding to the upper wall of the storage hole 81. A second spring storage hole 90 is formed. A first spring 91 is housed in the first spring housing hole 85, and the first spring 91 urges the weight member 82 in a circumferential direction with a predetermined spring force. A second spring 92 is housed in the second spring housing hole 90, and the second spring 92 is moved by a predetermined spring force to the weight member 8.
2 is urged toward the center of the rotary valve 11.

A drain hole 93 for communicating the storage hole 81 with the low-pressure chamber 54 is formed in the rotary valve 11, and the drain hole 93 is connected to the large-diameter portion 93A opening to the low-pressure chamber 54 and the large-diameter portion 93A. And a small-diameter portion 93B opening at 81. Small diameter portion 93B of drain hole 93
When the hydraulic pressure is not applied, the ball 94 is seated at the small diameter portion 93 of the drain hole 93.
A drain hole 93 is opened apart from the opening B.

When the weight member 82 is stationary, the ball 94 closes the drain hole 93 by hydraulic pressure. When the vehicle speed does not reach a certain value or more and the centrifugal force applied to the weight member 82 is smaller than the spring force of the second spring 92 until the centrifugal force also becomes a certain value or more, the weight member 82 is indicated by an arrow d. Do not move in the indicated centrifugal direction. Therefore, the ball 94 keeps the drain hole 93 closed.

When the vehicle speed exceeds a certain value and the centrifugal force also exceeds a certain value, the centrifugal force applied to the weight member 82 becomes larger than the spring force of the second spring 92. It moves in the centrifugal direction indicated by arrow d against the force. At this time, the weight member 82 is actuated by the action of the cam surface 83 of the weight member 82.
Is the arrow e against the spring force of the first spring 91
It moves in the circumferential direction shown by. Therefore, the weight member 82
Moves the ball 94 to open the drain hole 93. When the drain hole 93 is opened, the high-pressure oil in the storage hole 81 is drained to the low-pressure chamber 54 through the drain hole 93.

During the ABS operation of the vehicle, that is, when the joint rotates rapidly, the weight member 82 moves against the spring force of the first spring 91 in the circumferential direction indicated by the arrow e. Therefore, the flat portion 87 of the weight member 82 moves the ball 94 to open the drain hole 93. When the vehicle suddenly starts, the weight member 82 tends to move in the opposite circumferential direction indicated by the arrow f due to the centrifugal force.
Since the second cam surface 83 comes into contact with the tapered surface of the storage hole 81, it cannot be moved. Therefore, the ball 94 keeps the drain hole 93 closed.

Next, the operation will be described. As shown in FIG. 4, the centrifugal force applied to the weight member 82 is smaller than the spring force of the second spring 92 until the vehicle speed V becomes the centrifugal off vehicle speed V0.
The centrifugal direction indicated by does not move. The ball 94 keeps the drain hole 93 closed, and no torque cut is performed. FIG. 6 shows the torque characteristics when the torque cut is not performed.

When the vehicle speed V exceeds the centrifugal off vehicle speed V0, the centrifugal force applied to the weight member 82 is reduced by the second spring 92.
, The weight member 82 moves in the centrifugal direction indicated by the arrow d. At this time, the weight member 82 acts against the spring force of the first spring 91 by the action of the cam surface 83 and is indicated by the arrow e. Move in the direction. For this reason, the ball 94 is pressed and moved by the flat portion 87 of the weight member 82 and opens the drain hole 93. When the drain hole 93 is opened, the high-pressure oil in the storage hole 81 is drained to the low-pressure chamber 54 through the drain hole 93. Thus, a torque cut is performed. The torque characteristic of this torque cut is shown in FIG.

As described above, when the centrifugal force F does not reach the fixed value F0, the ball 94 blocks the drain hole 93 by hydraulic pressure, so that a decrease in torque due to oil leak can be prevented. Further, the discharge port 14 is expanded to accommodate the storage hole 81.
Is formed, and the weight member 82, the first and second springs 91 and 92, and the ball 94 are collectively stored in the storage hole 81, so that a large gap can be provided between the respective components, and malfunction of the components can be avoided. can do.

Further, during the ABS operation of the vehicle, the weight member 82 moves in the circumferential direction indicated by arrow e against the spring force of the first spring 91 due to the deceleration / acceleration force.
For this reason, the ball 94 is attached to the flat portion 87 of the weight member 82.
And the drain hole 93 is opened. The high-pressure oil in the storage hole 81 is drained to the low-pressure chamber 54 through the drain hole 93, and the torque is cut. Thus, AB
Matching with S can be performed.

At the time of sudden start, the weight member 82 tends to move in the opposite circumferential direction due to centrifugal force due to the centrifugal force. However, the cam surface 83 of the weight member 82 comes into contact with the tapered surface of the storage hole 81 and cannot operate. . Therefore, the ball 94
, The drain hole 93 is kept closed, and no torque cut is performed.

[0067]

As described above, according to the present invention, it is possible to prevent a decrease in torque due to oil leak and to avoid a malfunction due to contamination clogging. Also, when the centrifugal force exceeds a certain value,
Since the ball is moved in balance with the moment force, the force acting on the ball is small.

When the ABS is activated, the ball is moved to open the drain hole to cut the torque, and when the vehicle starts suddenly, the ball can be cut off without closing the drain hole.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part.

FIG. 3 is an explanatory view of the balance of moment force.

FIG. 4 is a graph showing the relationship between vehicle speed, centrifugal force, and limit torque.

FIG. 5 is a graph showing torque characteristics after torque cut.

FIG. 6 is a graph showing torque characteristics when torque is not cut;

FIG. 7 is a sectional view of a main part showing a second embodiment of the present invention.

FIG. 8 is a sectional view of a main part showing a third embodiment of the present invention.

FIG. 9 shows a conventional example.

FIG. 10 is an explanatory diagram of a conventional initial state.

FIG. 11 is an explanatory view at the time of a conventional operation.

[Explanation of symbols]

 1: cam 2: cam surface 3: welded portion 4: cam housing 5: rotor 6: input shaft 7: plunger chamber 8: plunger 9: return spring 10: suction / discharge hole 11: rotary valve 12: suction port 13: Suction path 14: Discharge port 15: Communication groove 16: Lid member 17: Notch 18: Projection 19: Bearing retainer 20: Bearing 21: Thrust needle bearing 22: Oil seal 23: Accumulator piston 24: Lid member 25: Accumulator chamber 26 , 27: oil passage 28: high pressure chamber 29: plug 30: lubrication hole 31: needle bearing 32: screw hole 33, 34: O-ring 35, 36: snap ring 37: mounting hole 38: through hole 39: collar member 40: Ball 41: Storage chamber 42, 43: Opening 44: Communication hole 45: Pin Material 46: storage hole 47: pin portion 48: base end 49: orifice 50: valve seat 51: spring 52: roll pin 54: low pressure chamber 61, 71, 81: storage hole 62, 72, 82: weight member 62A, 84 , 87, 88: flat portion 62B, 86: tapered surface 63, 73: spring receiving hole 64, 75: spring 65, 76, 93: drain hole 65A, 76A, 93A: large diameter portion 65B, 76B, 93B: small diameter portion 66, 78, 94: ball 74: retainer 77: ball storage groove 83: cam surface 85: first spring storage hole 89: surface 90: second spring storage hole 91: first spring 92: second spring

Claims (6)

[Claims] A cam housing provided between input and output shafts rotatable relative to each other and connected to said one shaft and having a cam surface having two or more peaks on an inner surface; and connected to said other shaft. And a rotor rotatably housed in the cam housing and having a plurality of plunger chambers formed in the axial direction; each of the plurality of plunger chambers being reciprocally movable by being pressed by a return spring. A plurality of plungers housed and driven by the cam surface when the two shafts rotate relative to each other; a suction / discharge hole formed in the rotor and communicating with the plunger chamber; and a rotatable end face of the rotor. A plurality of suction valves which are in sliding contact with each other and are positioned in a predetermined relationship with the cam housing, and act as suction and discharge valves depending on the positional relationship with the suction and discharge holes. A rotary valve having a port and a discharge port formed on the surface thereof; and a flow resistance generating means for generating a flow resistance by the flow of the discharge oil by driving the plunger; transmitting a torque corresponding to a rotational speed difference between the two shafts. In the hydraulic power transmission coupling, a storage hole formed by expanding the discharge port, a drain hole communicating the storage hole with the low pressure chamber side, and a ball stored in the storage hole to close the drain hole And a weight member that is movably stored in the storage hole and moves by centrifugal force when the vehicle speed reaches a constant value to press and move the ball to open the drain hole. Hydraulic power transmission coupling. 2. The hydraulic power transmission coupling according to claim 1, wherein the weight member has a tapered surface which presses and moves the ball by a moment force. 3. The hydraulic power transmission joint according to claim 1, wherein a ball housing groove for housing the ball is formed in the weight member. 4. The hydraulic power transmission coupling according to claim 1, wherein a cam surface is formed at one end of the weight member,
A hydraulic power transmission joint characterized in that a flat portion for pressing the ball is formed at the other end. 5. The hydraulic power transmission coupling according to claim 2, wherein a spring receiving hole is formed in the weight member, and a spring for urging the weight member toward the center of the rotary valve is provided in the spring receiving hole. A hydraulic power transmission joint characterized by being housed in a housing. 6. The hydraulic power transmission coupling according to claim 4, wherein a first spring storage hole and a second spring storage hole are formed in the weight member, and the weight member is formed in the second spring storage hole. A first spring that biases toward the center of the rotary valve is housed, and a second spring that biases the weight member in a predetermined circumferential direction is housed in a second spring housing hole. Hydraulic power transmission coupling.