JPH0735159A - Hydraulic power transmission coupling - Google Patents

Abstract

PURPOSE:To prevent any drop in torque from occurring, to be hard to cause the seizure or binding of a valve element to make durability improvable and embody the promotion of miniaturization and the cost reduction in addition to ease of production, in regard to a hydraulic power transmission coupling in use for a distribution of car driving force. CONSTITUTION:This power transmission coupling is provided with a third port 19 being installed on a valve surface of a valve element 11 and closed by the end face of a rotor 4, while at the case of being tuned to a high-pressure state, releasing the coheringness between the rotor 4 and the valve element 11, a high pressure chamber 15 being installed in the valve element 11 and made up of interconnecting a discharge port 13, two control valves 33 and 31 controlling conductingness between the third port 19 and a low pressure chamber in a coupling and another conductingness between the third port 19 and the high pressure chamber 15, and an actuator operating these control valves 33, 31 by a signal from the outside, respectively. In succession, pressure in the third port 19 is constituted so as to make it selectable to both high and low pressure states.

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. 3-342606. This hydraulic power transmission joint is provided between an input / output shaft capable of relative rotation, and a hydraulic pump driven by differential rotation of the both shafts; A control valve for controlling; and an actuator for operating the control valve in response to an external signal;
In a hydraulic power transmission joint for transmitting a torque according to a rotational speed difference between the both shafts and a control signal from the outside; a cam having a plurality of peaks coupled to one of the input / output shafts and the other shaft A rotor coupled to the cam, a plurality of plungers that are reciprocated by the cam and the rotor relative to the cam relative to each other, and suction that communicates with a plunger chamber that opens in the end face of the rotor and stores the plunger. A valve body provided with a discharge port and an end surface of the rotor, the suction port serving as a suction valve and a discharge valve depending on the positional relationship between the suction port and the suction port, and a valve body having a discharge port; A preload mechanism for maintaining a close contact state, a high-pressure chamber provided in the valve body and communicating with the discharge port, and a valve surface of the valve body, and a valve face of the rotor. And a control valve for controlling the conduction state between the third port and the high pressure chamber, wherein the actuator controls conduction and non-conduction of the control valve by a signal from the outside, When the control valve is in the conductive state, the oil pressure generated in the third port separates the contact state between the rotor and the valve body.

That is, in this hydraulic power transmission coupling, a third port other than the suction port and the discharge port is provided on the rotary valve surface of the hydraulic pump, and the hydraulic pressure from the high pressure chamber is introduced into this port, whereby the rotary valve is connected. This is to break the oil pressure balance on the surface, open the close contact seal state between the rotor and the rotary valve, and free the joint. Also,
The applicant has proposed the following hydraulic power transmission joint in Japanese Patent Application No. 4-331307.

This hydraulic power transmission coupling is provided between relatively rotatable input / output shafts, and has a positive displacement oil pump which operates by relative rotation between the input / output shafts in a housing in which oil is sealed. A valve that opens and closes the high-pressure oil passage by operating a signal from the outside in the high-pressure oil passage on the way from the oil pump to the flow resistance generating means while providing the flow resistance generating means in the discharge oil passage of the oil pump. In a hydraulic power transmission joint that is provided with a mechanism and generates torque according to a relative rotation speed between the input and output shafts and a control signal from the outside, the high pressure oil passage is provided inside, and a part of the oil pump is provided. The constituent valve element communicates with the low pressure chamber in the joint and is maintained at the same pressure, and the first and second oil chambers provided on both sides of the valve element pass through the high pressure oil passage to 1
Oil chamber and a second oil chamber so as to pass through the valve body, a cylindrical hole penetrating the valve body, and a movable body along the axis of the cylindrical hole. A poppet valve portion for opening and closing the first oil chamber, a piston portion for holding the high-pressure oil passage and the second oil chamber in a sealed state are integrally formed, and a seal portion diameter of the poppet valve portion and a piston portion are formed. It has a free control valve with the same diameter.

That is, in this hydraulic power transmission joint, a pressure balance type poppet valve is used as a free control valve to allow the pressure oil in the high pressure chamber to directly escape to the low pressure chamber.

[0006]

However, such a conventional hydraulic power transmission joint has the following problems in the former case. (1) When not freed, the third port is in a closed state, and oil leaking from the discharge port through the seal land accumulates in the same port, causing the oil pressure balance on the rotary valve surface to collapse, The rotor and rotary valve cannot be kept in close contact. Therefore, there is an oil leak and a torque drop occurs. (2) Since the third port is dented over the entire area, it is not possible to take a large bearing area to support the thrust load during normal torque transmission. Therefore, the durability of the valve surface was reduced. (3) Since the third port is arranged on the outer diameter side of the suction port and the discharge port, the oil passage configuration becomes complicated. Therefore, production is not easy. (4) The spool valve is a control valve that controls the conduction of hydraulic pressure to the third port, which causes a large amount of leakage during normal operation and a large risk of sticking.

On the other hand, also in the latter case, there are the following problems. (1) Since there is a spool portion in a part of the control valve, oil leaks from the valve skimmer even when the control valve is not freed, and torque decreases due to temperature rise. (2) Foreign matter is apt to be caught in the valve clearance, and there is a risk of the control valve sticking. (3) In order to keep the torque in the free state small, it is necessary to reduce the flow resistance of the passage, and it is necessary to make the cross-sectional area of the introduction oil passage to the high pressure chamber and the free control valve sufficiently large. As a result, the rotary valve becomes large and the cost becomes high.

The present invention has been made in view of the above-mentioned problems of the prior art. The torque does not decrease, the valve body is less likely to stick, and the durability is improved. It is an object of the present invention to provide a hydraulic power transmission joint that is easy to produce and can be downsized and reduced in cost.

[0009]

In order to achieve the above-mentioned object, the present invention is provided between input / output shafts capable of relative rotation,
A hydraulic pump driven by the differential rotation of the both shafts;
A control valve provided at the outlet of the hydraulic pump for controlling the flow resistance of the discharged oil; and an actuator for operating the control valve in response to an external signal; a rotational speed difference between the two shafts and an external control signal In a hydraulic power transmission joint for transmitting torque according to: a plurality of cams in which the hydraulic pump is connected to one of the input / output shafts and has a plurality of peaks, and a plurality of cams connected to the other shaft and open on one side surface. A rotor having a plunger chamber, a plurality of plungers housed in the plunger chamber and reciprocally moved by being restricted by the cam due to relative rotation of the cam and the rotor, and a plunger of the rotor. Depending on the positional relationship between the suction / discharge hole that opens to the other end surface that is not housed and communicates with the plunger chamber, and the suction / discharge hole that is provided in contact with the end surface of the rotor. A valve body having an intake port and a discharge port that act as inlet and outlet valves, and a preload mechanism for keeping the rotor and valve body in close contact with each other; provided on the valve face of the valve body And a third port that is closed by the end surface of the rotor and that releases the close contact state between the rotor and the valve body due to the pressure when the pressure becomes high, and that is provided in the valve body and connects the discharge port. A control valve that controls the electrical connection between the created high pressure chamber, the third port and the low pressure chamber in the joint, and the electrical connection between the third port and the high pressure chamber; It is characterized in that the actuator for operating the control valve is provided, and the pressure of the third port can be switched between two high and low pressure states.

Further, the present invention is characterized in that the third port is arranged on the inner diameter side of the suction port and the discharge port. In addition, the present invention provides, in the third port,
A bearing pad portion that is flush with the valve surface of the valve body is provided. Further, the invention is characterized in that the third port is provided on the end face side of the rotor.

Further, the present invention is characterized in that the control valve is constituted by a rod-shaped member having a conical or spherical shape at its tip and a diameter larger than the hole diameter. Further, the present invention is
It is characterized in that the electrical connection between the third port and the low-pressure chamber in the joint is always maintained. Also, the present invention is characterized in that the orifice provided at the outlet of the hydraulic pump is controlled to be opened and closed by the control valve.

In addition, the present invention is characterized in that a second orifice is provided at the outlet of the hydraulic pump in addition to the orifice, and the second orifice is always open.

[0013]

According to the hydraulic power transmission joint of the present invention having such a configuration, the oil accumulated in the third port is discharged to the low pressure chamber when the joint is not freed. Is eliminated, and the close contact between the rotor and the valve element can be maintained, so that torque reduction can be prevented.

Further, since the control valve has a conical or spherical shape at its tip and is made of a rod-shaped member thicker than the hole diameter, sticking hardly occurs and reliability can be improved. Further, since the bearing pad portion that is flush with the valve surface of the valve body is provided in the third port, it is possible to secure a large area for receiving the thrust load and improve the durability of the valve body.

Further, since the third port is provided on the inner diameter side of the suction port and the discharge port, the oil passage structure is simplified and the production is facilitated. Further, since the cross-sectional area of the high pressure chamber may be small, the valve body is small and the cost is low.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 15 are views showing an embodiment of the present invention. FIG. 1 is a sectional view according to an embodiment of the present invention. First, the structure will be described. In FIG. 1, 1 is a housing, and the housing 1 is connected to an output shaft (not shown).
Rotates integrally with the output shaft.

The housing 1 is composed of a housing non-magnetic portion 1A made of a non-magnetic material and another portion made of a magnetic material including the member 2 having the spline 2A. Three
Is a cam, and the cam 3 is supported on the inner surface of the housing 1 so as to be rotatable by a predetermined angle. The cam 3 has a cam surface 3A composed of a plurality of cam peaks and cam valleys, and on the outer periphery thereof,
A plurality of protrusions 3B for positioning and transmitting torque are provided on the side surface where the cam ridge is located.

When the projection 3B of the cam 3 engages with the notch 1B formed in the housing 1 to rotate integrally with the housing 1 in the rotation direction of the rotor 4, and when the rotation direction of the rotor 4 changes, the cam 3 Moves around with the rotor 4, and the cam 3
The protrusion 3B rotates until it contacts the notch 1B of the housing 1, and then rotates integrally with the housing 1. The rotor 4 is rotatably accommodated in the housing 1, is coupled to the input shaft 5, and rotates together with the input shaft 5.

A plurality of plunger chambers 6 are formed in the rotor 4 in the axial direction, and a plurality of plungers 7 slide in the plunger chamber 6 via return springs 8 which also function as a preload mechanism. It is stored freely. Further, the rotor 4 is formed with a plurality of suction / discharge holes 9 so as to communicate with the respective plunger chambers 6. The valve side surface of the rotor 4 is shown in FIG.

A plurality of suction and discharge holes 9 are formed in the rotor 4 in the circumferential direction, and the suction and discharge holes 9 communicate with the plunger chambers 6, respectively. A spline 10 is formed on the inner circumference of the rotor 4, and the rotor 4 is spline-coupled to the input shaft 5. Referring again to FIG. 1, reference numeral 11 denotes a rotary valve as a valve body in which the suction port 12 and the discharge port 13 are formed, and the rotary valve 11 engages the notch 1 </ b> B of the housing 1 with the projection 14 to make the housing 1 Positioned and fixed to.

The discharge port 13 communicates with the high pressure chamber 15, and an orifice 16 as a flow resistance generating means is formed at the outlet of the high pressure chamber 15. Also, rotary valve 1
1, a relief hole 17 communicating with the high pressure chamber 15 is formed, and the relief hole 17 is opened on the back side of the rotary valve 11. A discharge hole 18 is formed in the rotary valve 11, and the discharge hole 18 communicates with the suction port 12 and opens on the back side of the rotary valve 11. The discharge hole 18 discharges the oil accumulated in the third port 19 formed on the surface side of the rotary valve 11 when it is not free.

Next, FIG. 3 shows the surface side of the rotary valve 11. In FIG. 3, a plurality of suction ports 12 that are open to the outer circumference of the rotary valve 11 are formed in the circumferential direction,
A plurality of discharge ports 13 are formed between the suction ports 12. The third port 19 has a bearing pad portion 20 which is formed on the inner diameter side of the suction port 12 and the discharge port 13 and is flush with the valve surface of the rotary valve 11.

The third port 19 is formed on the end surface side of the rotor 4 or the surface side of the rotary valve 11. A plurality of oil drain holes 21 communicating with the third port 19 are formed in the rotary valve 11, and the oil drain holes 21 are opened on the back surface of the rotary valve 11. The oil drain hole 21 drains the oil accumulated in the third port 19 when it is not free, and the high pressure oil flows back from the oil drain hole 21 to the third port 19 when it is free. There is.

The outflow passage 2 is provided on the outer circumference of the rotary valve 11.
2 is formed, and the discharge oil from the orifice 16 flows out from the outflow passage 22 into the low pressure chamber in the joint. That is, the outflow passage 22 does not allow the oil discharged from the orifice 16 to flow to the oil chamber side provided with the movable magnetic body described later, and the plunger chamber 6
I try to let it leak to the side. Again in FIG. 1, 2
3 is a retainer provided in contact with the rotary valve 11, the retainer 23 is supported by a bearing 24,
It rotates integrally with the housing 1. A seal ring 25 is interposed between the retainer 23 and the input shaft 5, the seal ring 25 prevents oil leakage, and a stopper ring 26 provided on the inner circumference of the housing 1 moves the retainer 23 to the right in the figure. Prevent.

A first groove 27 communicating with the orifice 16 of the rotary valve 11 is formed in the retainer 23, and the first groove 27 communicates with the outflow passage 22. 28 is a lock valve as a control valve, and the lock valve 28 is a retainer 23.
Slidably inserted into the first groove 27 and protruding into the first groove 27,
The orifice 16 is opened and closed. The lock valve 28 is concentrically arranged with the orifice 16 and has a conical or spherical shape at its tip and is made of a rod-shaped member thicker than the orifice hole diameter so as to directly close the orifice 16.

A second groove 29 communicating with the high pressure chamber 15 of the rotary valve 11 is formed in the retainer 23, and
The third communicating with the relief hole 17 of the rotary valve 11
Groove 30 is formed. Reference numeral 31 is a relief valve as a control valve, and the relief valve 31 is slidably inserted into the retainer 23 and projects into the third groove 30 to open and close the relief hole 17.

The relief valve 31 is concentrically arranged with the relief hole 17 and has a conical or spherical tip, and is made of a rod-shaped member thicker than the relief hole diameter.
It is designed to directly block. The oil discharge hole 21 communicating with the third port 19 and the discharge hole 18 of the rotary valve 11 also communicate with the third groove 30.

Reference numeral 33 is a free valve as a control valve. The free valve 33 is slidably inserted in the retainer 23 and projects into the third groove 30 to open and close the discharge hole 18. The free valve 33 has a conical or spherical shape whose tip portion is arranged concentrically with the discharge hole 18 and is made of a rod-shaped member thicker than the diameter of the discharge hole to directly close the discharge hole 18.

Reference numeral 34 denotes a movable magnetic body that generates a magnetic attraction force by energizing the solenoid coil 35, and the movable magnetic body 34 is movably accommodated in the housing 1. When a weak current is applied to the solenoid coil 35, the upper side of the movable magnetic body 34 is attracted to the retainer 23 side, the lock valve 28 is activated, and when a strong current is applied to the solenoid coil 35, the entire circumference of the movable magnetic body 34 is retained. 23 is sucked, and the free valve 33 and the relief valve 31 are operated via the reversing lever 36.

Next, FIG. 4 shows the movable magnetic body 34 and the reversing lever 36. In FIG. 4, a return spring 37 is interposed between the lower side of the movable magnetic body 34 and the retainer 23. Therefore, when the solenoid coil 35 is weakly energized, the upper side of the movable magnetic body 34 is attracted to the retainer 23 side, and the lock valve 28 is activated. On the other hand, when the solenoid coil 35 is strongly energized, the entire circumference of the movable magnetic body 34 is retained. 23
The free valve 33 and the relief valve 31 are actuated. That is, the free valve 33 closes the discharge hole 18,
The relief valve 31 opens the relief hole 17.

The lower side of the reversing lever 36 and the retainer 2
3 is provided with a relief pressure setting spring 38, and when the pressure in the high pressure chamber 15 exceeds the set value of the relief pressure setting spring 38 in the normal characteristic and the lock characteristic, the relief valve 31 is activated and the relief pressure is set. Open the hole 17 (see FIG. 10). This can prevent the generation of excessive torque. Reversing lever 36
Is provided with a fulcrum 39, the reversing lever 36 swings about the fulcrum 39, and the free valve 33 and the relief valve 3
Activate 1.

When the oil is not free, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 and the third groove 30 (see FIG. 9). When free,
The oil in the high-pressure chamber 15 passes through the relief hole 17 and the third groove 30, flows back into the oil drain hole 21, and flows into the third port 19 (see FIGS. 11 and 12). Referring again to FIG. 1, reference numeral 41 denotes an inner cover formed of a non-magnetic sheet metal. The outer peripheral portion of the inner cover 41 is inserted into the housing 1, and the inner peripheral portion is fixed to the retainer 23. Inner cover 4
1 has a function as a stopper for preventing the movable magnetic body 34 from moving to the right, and a fulcrum 39 of the reversing lever 36 contacts.

The inner cover 41 is formed to have a predetermined shape and restricts the deformation of the diaphragm 43 housed between the cover 42 fixed to the housing 1 and the retainer 23. The diaphragm 43 has a function as an accumulator that absorbs thermal expansion of the enclosed oil,
Air 44 is enclosed inside. Inner cover 4
A communication hole 45 is formed in the first hole 1, and the enclosed oil can flow in and out through the communication hole 45.

Reference numeral 46 is a first magnetic frame, and the first magnetic frame 46 is fixed to an external member by a bolt 47 and is held in a non-contact state with a joint. The first magnetic frame 46 is arranged concentrically with respect to the joint shaft, and the solenoid coil 35 is housed in the first magnetic frame 46. Reference numeral 48 is a second magnetic frame, and the second magnetic frame 48 is fixed to the housing 1. The first and second magnetic frames 46 and 48 and the solenoid coil 35 collectively constitute an actuator that operates the movable magnetic body 34 by an external signal.

In addition, 49 and 50 are oiling holes, 51 is a seal ring, 52 is a needle bearing, and 53 is a stopper ring. Next, the operation will be described. First, the normal characteristics will be described. When the solenoid coil 35 is not energized, the movable magnetic body 34 does not generate a magnetic attraction force and is held at the position shown in FIG. Therefore, the return spring 3
7 is not compressed, the reversing lever 36 does not swing, and is held at the position shown in FIG.

Therefore, the relief valve 31 is pressed by the reversing lever 36 by the load of the relief pressure setting spring 38 to close the relief hole 17. The free valve 33 opens the discharge hole 18 because the reversing lever 36 does not swing. On the other hand, the lock valve 28 opens the orifice 16 because there is no attraction force of the movable magnetic body 34. Therefore, the oil flows as shown by the arrow A. That is, the discharge port 1
The oil extruded to 3 passes through the high pressure chamber 15 and the orifice 16 and is supplied to the suction port 12 via the outflow passage 22.

The resistance of the orifice 16 raises the hydraulic pressure in the high pressure chamber 15, the discharge port 13 and the plunger chamber 6 to generate a reaction force in the plunger 7. A torque is generated by rotating the cam 3 against the plunger reaction force, and the torque is transmitted between the cam 3 and the rotor 4. The torque characteristic at this time is shown in B of FIG.
The torque T is proportional to the square of the differential rotation speed ΔN.

As shown in FIG. 7, in this normal characteristic, the pressure distribution for moving the rotor 4 to the left, that is, for separating the rotor 4 from the rotary valve 11 is as shown by C, and In the pressure distribution C, the close contact state between the rotor 4 and the rotary valve 11 is maintained. The pressure distribution C is determined by the discharge port 13 and the seal land portions 54 and 55.

Next, the lock characteristic will be described. When the solenoid coil 35 is weakly energized, only the upper side of the movable magnetic body 34, which is not provided with the return spring 37, is attracted to the retainer 23 side, presses the lock valve 28, and closes the orifice 16 (see FIG. 8). ). On the other hand, since the lower side of the movable magnetic body 34 does not move, the reversing lever 36
Does not swing, the free valve 33 keeps the discharge hole 18 open, and the relief valve 31 is pressed by the reversing lever 36 by the load of the relief pressure setting spring 38, and the relief hole 17 remains closed.

Since the outlet of the oil discharged from the plunger chamber 6 is blocked, the joint is locked. The torque characteristic at this time is shown by D in FIG. As shown in FIG. 7, the pressure distribution with the lock characteristic is the same as the pressure distribution C with the normal characteristic, and the contact state between the rotor 4 and the rotary valve 11 is maintained.

Next, the discharge of the leak oil in the normal characteristic and the lock characteristic will be described. In the normal characteristic and the lock characteristic, the high-pressure oil in the discharge port 13 leaks through the seal land portions 54 and 55, though only slightly. In the state where the discharge hole 18 is closed by the free valve 33, this leak oil collects in the third port 19 and floats the rotor 4 from the valve surface.
In the present embodiment, as shown in FIG. 9, the oil accumulated in the third port 19 is the oil drain hole 2 as shown by the arrow E.
1 through the third groove 30 and through the discharge hole 18 into the intake port 12. In this way, it is possible to prevent the rotor 4 from floating above the valve surface.

Next, the relief operation will be described. In the normal characteristic and the lock characteristic, when the pressure in the high pressure chamber 15 exceeds a predetermined value determined by the strength of the relief pressure setting spring 38, the relief valve 31 moves to the right side as shown in FIG. 17 and open the reversing lever 36
The free valve 33 does not completely close the discharge hole 18, though the free valve 33 is swung to close the free valve 33. Therefore, the pressure oil in the high-pressure chamber 15 passes through the orifice 16 as shown by the arrow F, passes through the relief hole 17 and the third groove 30 as shown by the arrow G, and then flows from the discharge hole 18 to the suction port 12. Flowing.

Therefore, no pressure higher than the relief pressure is generated. Therefore, the transmission torque does not exceed the value determined by the relief pressure. The torque characteristic is as shown by H in FIG. Next, the free characteristics will be described. When the solenoid coil 35 is energized strongly, FIG. 11 and FIG.
As shown in FIG. 2, the movable magnetic body 34 overcomes the load of the return spring 37, and the entire circumference is attracted to the retainer 23 side. Since the lock valve 28 closes the orifice 16 and the reversing lever 36 swings, the relief valve 31 opens the relief hole 17 and the free valve 33 closes the discharge hole 18.

Therefore, the pressure oil in the high-pressure chamber 15 flows from the relief hole 17, the third groove 30 to the oil drain hole 2 as shown by the arrow I.
Backflow to 1 and enter third port 19. Due to this backflow, the hydraulic balance of the rotary valve 11 is lost and the close contact with the rotor 4 is lost. That is, in this free characteristic, the pressure distribution is as shown by J in FIG. 7, and the contact state between the rotor 4 and the rotary valve 11 is lost.
At this time, the pressure distribution J that moves the rotor 4 to the left is
It is determined by the discharge port 13, the seal land portions 54, 55, the third port 19 and the third port seal land 56.

Therefore, the main stream of oil (arrow K) from the plunger chamber 6 flows out from the gap between the rotor 4 and the rotary valve 11. The torque characteristic at this time is shown by L in FIG. 6 and is in a free state. Next, FIGS.
FIG. 3 is a diagram showing the above-described first embodiment of the present invention. FIG.
Is an explanatory diagram of normal characteristics.

In FIG. 13, the orifice 16 is opened, the relief hole 17 is closed by the relief valve 31, and the discharge hole 1
Open valve 8 with free valve 33. This gives the joint its normal properties. On the other hand, the oil accumulated in the third port 19 is
As shown by, the oil is discharged from the discharge hole 18 through the oil discharge hole 21. FIG. 14 is an explanatory diagram of lock characteristics.

In FIG. 14, the orifice 16 is closed by the lock valve 28, the relief hole 17 is closed by the relief valve 31, and the discharge hole 18 is opened by the free valve 33. This allows
The joint has locking characteristics. On the other hand, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as shown by the arrow N. FIG. 15 is an explanatory diagram of free characteristics.

In FIG. 15, when the lock valve 28 closes the orifice 16, the relief hole 17 is opened by the relief valve 31, and the discharge hole 18 is closed by the free valve 33, the high pressure chamber 15
The pressure oil of No. 2 passes through the relief hole 17 as shown by the arrow O, flows back to the oil discharge hole 21, and enters the third port 19. Therefore, the contact between the rotor 4 and the rotary valve 11 is lost, and the free characteristic is obtained.

As described above, when not freed, the oil accumulated in the third port 19 is discharged from the discharge hole 18, so that the rotor 4 and the rotary valve 11 can be kept in close contact with each other. Since there is no oil leak, it is possible to prevent a decrease in torque. Relief valve 3
Since 1 and the free valve 33 are configured with a rod-shaped member whose tip portion has a conical or spherical shape and are thicker than the relief hole diameter and the discharge hole diameter, sticking hardly occurs and reliability can be improved.

In the third port 19, the bearing pad portion 2 is flush with the valve surface of the rotary valve 11.
Since 0 is provided, the thrust area that receives the thrust load during normal torque transmission can be widened, and the durability of the rotary valve 11 can be improved. Also, the third
Since the port 19 is formed on the inner diameter side of the suction port 12 and the discharge port 13, the oil passage configuration has a simple shape, which simplifies the production.

Further, since the cross-sectional area of the high pressure chamber 15 may be small, the rotary valve 11 can be made small and the cost can be reduced. 16 to 18 are views showing a second embodiment of the present invention. In this embodiment,
Instead of providing a free valve that closes the discharge hole 18, the discharge hole 18 has a small diameter, so that the discharge hole 18 is always open.

FIG. 16 is an explanatory diagram of normal characteristics. FIG.
In, the orifice 16 is opened and the relief hole 17 of the high pressure chamber 15 is closed by the relief valve 31.
Therefore, the joint exhibits normal properties. On the other hand, the discharge hole 18
Is open, and the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as indicated by an arrow P.

FIG. 17 is an explanatory diagram of the lock characteristic. Figure 1
7, the orifice 16 is closed by the lock valve 28, and the relief hole 17 of the high pressure chamber 15 is closed by the relief valve 31. Therefore, the joint exhibits locking properties. On the other hand, the drain hole 18 is open, and the oil accumulated in the third port 19 is discharged from the drain hole 21 as shown by an arrow Q.
And is discharged from the discharge hole 18.

FIG. 18 is an explanatory diagram of free characteristics. Figure 1
8, the orifice 16 is closed by the lock valve 28, and the relief hole 17 of the high pressure chamber 15 is opened by the relief valve 31. Therefore, the pressure oil in the high pressure chamber 15 flows back to the oil discharge hole 21 and enters the third port 19 as shown by the arrow R, and the close contact between the rotor 4 and the rotary valve 11 is lost. Thus, the joint exhibits free properties. On the other hand, since the discharge hole 18 has a small diameter and is open, a part of the pressure oil in the high pressure chamber 15 is discharged from the discharge hole 18 as indicated by an arrow S.

Also in this embodiment, the same effect as that of the above embodiment can be obtained. Next, FIGS. 19 to 21 are views showing a third embodiment of the present invention. In this embodiment, the orifice 16 and the lock valve 31 are eliminated and the relief hole 1
7 as the orifice 57 and the relief valve 31 as the lock valve 5
The reversing lever 36 was also abolished.

FIG. 19 is an explanatory diagram of normal characteristics. FIG. 19
In, the orifice 57 is opened by the lock valve 58, and the discharge hole 18 is opened by the free valve 33. Therefore, the pressure oil in the high-pressure chamber 15 passes through the orifice 57 and is discharged from the discharge hole 18, as shown by the arrow W.

The joint thus exhibits the usual properties. on the other hand,
Since the discharge hole 18 is open, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as shown by the dotted line U. FIG. 20 is an explanatory diagram of lock characteristics. In FIG. 20, the orifice 57 is the lock valve 5
It is closed by No. 8 and the joint exhibits locking properties. On the other hand, since the discharge hole 18 is opened by the free valve 33, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as shown by an arrow V.

FIG. 21 is an explanatory diagram of free characteristics. Figure 2
In No. 1, the orifice 57 is opened by the lock valve 58, and the discharge hole 18 is closed by the free valve 33. Therefore, the pressure oil in the high pressure chamber 15 flows back to the oil drain hole 21 through the orifice 57 and enters the third port 19 as shown by the arrow X. In this way, the close contact between the rotor 4 and the rotary valve 11 is lost, and the joint exhibits free characteristics.

Also in this embodiment, the same effect as the above embodiment can be obtained. Next, FIGS. 22 to 24 are views showing a fourth embodiment of the present invention. In the present embodiment, the orifice 16 is the first orifice 59, and the relief hole 1
No. 7 is the second orifice 60, and the relief valve 31 and the reversing lever 36 are eliminated. FIG. 22 is an explanatory diagram of normal characteristics.

In FIG. 22, the first orifice 59 is open, the second orifice 60 is always open, and the discharge hole 1
8 is opened by a free valve 33. Therefore,
The pressure oil in the high pressure chamber 15 passes through the first orifice 59 and is discharged from the discharge hole 18 through the second orifice 60 as shown by the arrow a. Therefore, the joint exhibits normal properties. On the other hand, since the discharge hole 18 is opened, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as shown by the dotted line b.

FIG. 23 is an explanatory diagram of lock characteristics. Figure 2
3, the first orifice 59 is closed by the lock valve 28, the second orifice 60 is opened, and the discharge hole 18 is opened.
Is opened by the free valve 33. Since the second orifice 60 is opened, the pressure oil in the high pressure chamber 15 is discharged through the second orifice 60 as shown by the arrow c, but the first orifice 59 is closed by the lock valve 28. Since it is, it is almost in a state close to lock. On the other hand, since the discharge hole 18 is opened, the oil accumulated in the third port 19 is discharged from the discharge hole 18 through the oil discharge hole 21 as shown by the dotted line d.

FIG. 24 is an explanatory diagram of free characteristics. Figure 2
4, the first orifice 59 is closed by the lock valve 28, the second orifice 60 is opened, and the discharge hole 18
Is closed by the free valve 33. Therefore, the pressure oil in the high-pressure chamber 15 is supplied to the second orifice 6 as indicated by the arrow e.
0, flows back into the oil drain hole 21, and enters the third port 19. Therefore, the close contact between the rotor 4 and the rotary valve 11 is lost and the free characteristic is obtained.

Also in this embodiment, the same effect as the above embodiment can be obtained.

[0064]

As described above, according to the present invention, when it is not free, the oil accumulated in the third port can be discharged and the close contact between the rotor and the valve body can be maintained. Therefore, it is possible to prevent the torque from decreasing. Further, the control valve is less likely to be stuck, and the reliability can be improved.

Further, since the area for receiving the thrust load can be widened, the durability of the valve body can be improved. Further, since the oil passage for supplying the pressure oil to the third port can have a simple shape, the production becomes easy. Furthermore, since the cross-sectional area of the high-pressure chamber may be small, the valve body is small and the cost is low.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a valve side surface of a rotor.

[Figure 3] Surface view of rotary valve

FIG. 4 is a diagram showing a movable magnetic body and a reversing lever.

FIG. 5 is an explanatory diagram of normal characteristics

FIG. 6 is a graph showing torque characteristics

FIG. 7 is a diagram showing a valve surface hydraulic pressure balance.

FIG. 8 is an explanatory diagram of lock characteristics.

FIG. 9 is an explanatory diagram of leak oil discharge.

FIG. 10 is an explanatory diagram of a relief operation.

FIG. 11 is an explanatory diagram of free characteristics.

FIG. 12 is a diagram showing the flow of pressure oil when free.

FIG. 13 is an explanatory diagram of normal characteristics of the first embodiment.

FIG. 14 is an explanatory diagram of a lock characteristic of the first embodiment.

FIG. 15 is an explanatory diagram of free characteristics of the first embodiment.

FIG. 16 is an explanatory diagram of normal characteristics of the second embodiment.

FIG. 17 is an explanatory diagram of a lock characteristic of the second embodiment.

FIG. 18 is an explanatory diagram of free characteristics of the second embodiment.

FIG. 19 is an explanatory diagram of normal characteristics of the third embodiment.

FIG. 20 is an explanatory diagram of a lock characteristic of the third embodiment.

FIG. 21 is an explanatory diagram of free characteristics of the third embodiment.

FIG. 22 is an explanatory diagram of normal characteristics of the fourth embodiment.

FIG. 23 is an explanatory diagram of the lock characteristic of the fourth embodiment.

FIG. 24 is an explanatory diagram of free characteristics of the fourth embodiment.

[Explanation of symbols]

 1: Housing 1A: Nonmagnetic part of housing 1B: Notch 2: Member 2A: Spline 3: Cam 3A: Cam surface 3B: Protrusion 4: Rotor 5: Input shaft 6: Plunger chamber 7: Plunger 8: Return spring 9 : Inlet / outlet port 10: Spline 11: Rotary valve (valve body) 12: Inlet port 13: Outlet port 14: Protrusion 15: High pressure chamber 16: Orifice 17: Relief hole 18: Discharge hole 19: Third port 20: Bearing Pad part 21: Oil drain hole 22: Outflow passage 23: Retainer 24: Bearing 25: Seal ring 26: Stopper ring 27: First groove 28: Lock valve (first control valve) 29: Second groove 30: No. 3 groove 31: relief valve (third control valve) 33: free valve (second control valve) 34: movable magnetic body 35: solenoid coil 36: Rolling lever 37: Return spring 38: Relief pressure setting spring 39: Support point 41: Inner cover 42: Cover 43: Diaphragm 44: Air 45: Communication hole 46: First magnetic frame 47: Bolt 48: Second magnetic frame 49 , 50: Oiling hole 51: Seal ring 52: Needle bearing 53: Stopper ring 54, 55: Seal land part 56: Seal land part for third port 57: Orifice 58: Lock valve 59: First orifice 60: Second Orifice

Claims (8)

[Claims] 1. A hydraulic pump provided between relatively rotatable input and output shafts and driven by differential rotation of the both shafts; a control provided at an outlet of the hydraulic pump for controlling flow resistance of discharged oil. A valve and; an actuator for actuating the control valve in response to a signal from the outside; a hydraulic power transmission joint for transmitting a torque according to a rotational speed difference between the two shafts and a control signal from the outside; A cam having a plurality of peaks coupled to one of the input / output shafts, a rotor having a plurality of plunger chambers coupled to the other shaft and opening on one side surface, and housed in the plunger chambers A plurality of plungers that are reciprocally moved by being restricted by the cam due to relative rotation of the cam and the rotor; and an opening at another end surface of the rotor that does not house the plunger, A suction and discharge hole communicating with the suction chamber, a valve body provided in contact with the end surface of the rotor, the suction port acting as a suction valve and a discharge valve depending on the positional relationship with the suction and discharge hole, and a valve body having a discharge port, And a preload mechanism for keeping the rotor and the valve body in close contact; provided on the valve surface of the valve body,
A third port that is closed by the end surface of the rotor and that releases the close contact state between the rotor and the valve body due to the pressure when a high pressure state is formed, is provided in the valve body, and is made by communicating the discharge port. A high pressure chamber, a control valve for controlling a conduction state between the third port and a low pressure chamber in the joint, and a conduction state between the third port and the high pressure chamber, and the control valve according to a signal from the outside. A hydraulic power transmission joint comprising the actuator for activating the pressure control device, wherein the pressure of the third port can be switched between two high and low pressure states. 2. The hydraulic power transmission joint according to claim 1, wherein the third port is arranged on the inner diameter side of the suction port and the discharge port. 3. The hydraulic power transmission joint according to claim 1, wherein a bearing pad portion that is flush with the valve surface of the valve body is provided in the third port. 4. The hydraulic power transmission joint according to claim 1, wherein the third port is provided on the end face side of the rotor. 5. The hydraulic power transmission joint according to claim 1, wherein the control valve is constituted by a rod-shaped member having a conical or spherical shape at its tip and a diameter larger than the hole diameter. 6. The hydraulic power transmission joint according to claim 1, wherein the electrical connection between the third port and the low pressure chamber in the joint is always maintained. 7. The hydraulic power transmission joint according to claim 1, wherein the orifice provided at the outlet of the hydraulic pump is controlled to be opened and closed by the control valve. 8. A hydraulic power transmission joint according to claim 6, wherein a second orifice is provided at the outlet of the hydraulic pump in addition to the orifice, and the second orifice is normally opened.