JP2989433B2 - Hydraulic power transmission coupling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art The present applicant has proposed a hydraulic power transmission coupling as described below in Japanese Patent Application No. 3-342606. The hydraulic power transmission coupling is provided between input and output shafts that are rotatable relative to each other, and is driven by differential rotation of the two shafts; and a hydraulic pump provided at an outlet of the hydraulic pump to reduce flow resistance of discharge oil. A control valve for controlling; an actuator for operating the control valve according to an external signal;
A hydraulic power transmission coupling for transmitting a torque according to a rotational speed difference between the two shafts and an external control signal; a cam having a plurality of peaks coupled to one of the input / output shafts, and one of the other shafts A plurality of plungers which are reciprocated while being regulated by the cam with the relative rotation of the cam and the rotor, and a suction opening to an end face of the rotor and communicating with a plunger chamber containing the plunger. A discharge port, a valve body provided with an end face of the rotor, and having a suction port and a discharge port that act as a suction valve and a discharge valve depending on a positional relationship with the suction and discharge port; A preload mechanism for maintaining the close contact state, a high-pressure chamber provided in the valve body and made to communicate with the discharge port, and a high-pressure chamber provided on the valve surface of the valve body, and a valve surface of the rotor. A third port closed and a control valve for controlling the state of conduction between the third port and the high-pressure chamber, and control the conduction and non-conduction of the control valve by an actuator with the signal from the outside, When the control valve is in a conductive state, the close contact between the rotor and the valve body is separated by hydraulic pressure generated at the third port.

That is, in this hydraulic power transmission coupling, a third port other than a suction port and a discharge port is provided on a rotary valve surface of a hydraulic pump, and hydraulic pressure from a high-pressure chamber is led to this port to thereby provide a rotary valve. This breaks the hydraulic balance of the surface, releases the tightly sealed state between the rotor and the rotary valve, and makes the joint free. Also,
The present applicant has proposed the following hydraulic power transmission coupling in Japanese Patent Application No. 4-331307.

The hydraulic power transmission coupling is provided between an input and output shaft that is rotatable relative to each other, and a positive displacement oil pump that is operated in a housing sealed with oil by the relative rotation between the input and output shafts. A valve for providing flow resistance generating means in a discharge oil passage of an oil pump, and for opening and closing the high pressure oil passage which is operated by an external signal in a high pressure oil passage on the way from the oil pump to the flow resistance generating means. A hydraulic power transmission coupling that generates a torque according to a relative rotation speed between the input and output shafts and an external control signal, the hydraulic power transmission coupling having the high-pressure oil passage therein, and a part of the oil pump. The first and second oil chambers provided on both sides of the valve body and the first and second oil chambers communicate with the low pressure chamber in the joint and are maintained at the same pressure. 1
An oil chamber, a cylindrical hole passing through the valve body so as to pass through the second oil chamber, and a movable hole along the axis of the cylindrical hole. A poppet valve for opening and closing the first oil chamber and a piston for holding the high-pressure oil passage and the second oil chamber in a sealed state integrally formed with each other; a seal portion diameter of the poppet valve; And a free control valve having the same diameter.

That is, in this hydraulic power transmission coupling, a pressure balanced type poppet valve is used as a free control valve so that pressure oil in a high pressure chamber is directly released to a low pressure chamber.

[0006]

However, such a conventional hydraulic power transmission coupling has the following problems in the former case. (1) When not made free, the third port is in a closed state, and oil leaking from the discharge port through the seal land accumulates in the port, so that the hydraulic balance on the rotary valve surface is lost, The rotor and rotary valve cannot be kept in close contact. As a result, there is an oil leak, and the torque is reduced. (2) Since the third port is recessed over the entire area, a large bearing area for supporting a thrust load during normal torque transmission cannot be obtained. As a result, 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 configuration of the oil passage becomes complicated. For this reason, production is not easy. (4) The control valve for controlling the conduction of the hydraulic pressure to the third port is a spool valve, which causes a large leakage during normal operation and a large danger of sticking.

On the other hand, the latter case also has the following problems. (1) Since the spool portion is provided in a part of the control valve, even when the control valve is not made free, oil leaks from the valve gap and the torque decreases due to a rise in temperature. (2) Foreign matter is easily clogged in the valve gap, and there is a risk of sticking of the control valve. (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 sufficiently increase the cross-sectional area of the high pressure chamber and the oil passage introduced to the free control valve. As a result, the size of the rotary valve increases, and the cost increases.

The present invention has been made in view of such conventional problems, and does not cause a decrease in torque, hardly causes sticking of a valve body, and can improve durability. It is an object of the present invention to provide a hydraulic power transmission coupling that can be easily manufactured, reduced in size and reduced in cost.

[0009]

In order to achieve the above object, the present invention is provided between input / output shafts which are rotatable relative to each other,
A hydraulic pump driven by the differential rotation of the two shafts;
A control valve provided at an outlet of the hydraulic pump for controlling flow resistance of discharge oil; 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 A hydraulic power transmission coupling for transmitting torque according to the following: the hydraulic pump is connected to one of the input / output shafts and has a plurality of cams; and the plurality of cams are 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 reciprocated by the cam with the relative rotation of the cam and the rotor; and a plunger of the rotor. An opening is provided on the other end face that is not accommodated, and a suction / discharge hole communicating with the plunger chamber is provided in contact with an end face of the rotor. A valve body provided with a suction port and a discharge port acting as an inlet valve and a discharge valve, and a preload mechanism for maintaining close contact between the rotor and the valve body; provided on a valve surface of the valve body A third port that is closed by the end face of the rotor and releases the close contact state between the rotor and the valve body by the pressure when the rotor is in a high pressure state, and is provided in the valve body, and communicates with the discharge port. A control valve for controlling the state of conduction between the created high-pressure chamber, the third port and the low-pressure chamber in the joint, and the state of conduction between the third port and the high-pressure chamber; and It is characterized by comprising the actuator for operating a control valve, and switching the pressure of the third port between two high and low pressure states.

Further, the present invention is characterized in that the third port is disposed on the inner diameter side of the suction port and the discharge port. Also, the present invention provides the third port,
The present invention is characterized in that a bearing pad portion which 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 an 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 the tip end and a diameter larger than the hole diameter. Also, the present invention
The continuity between the third port and the low-pressure chamber in the joint is always maintained. Further, the present invention is characterized in that an orifice provided at an outlet of the hydraulic pump is controlled to be opened and closed by the control valve.

Further, the present invention is characterized in that a second orifice is provided at the outlet of the hydraulic pump separately from 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, when the joint is not made free, the oil accumulated in the third port is discharged to the low pressure chamber. Is eliminated, and the rotor and the valve element can be kept in close contact with each other, so that torque reduction can be prevented.

Further, since the control valve is formed of a rod-shaped member having a conical or spherical shape at the tip end and having a diameter larger than the hole diameter, sticking hardly occurs and reliability can be improved. Further, since the third port is provided with the bearing pad portion which is flush with the valve surface of the valve body, the area for receiving the thrust load can be made large, and the durability of the valve body can be improved.

Further, since the third port is provided on the inner diameter side of the suction port and the discharge port, the configuration of the oil passage is simplified, and the production is facilitated. Furthermore, 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 one embodiment of the present invention. First, the structure will be described. In FIG. 1, reference numeral 1 denotes a housing, and the housing 1 is connected to an output shaft (not shown).
It rotates integrally with the output shaft.

The housing 1 includes 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. 3
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 ridges and cam valleys.
A plurality of projections 3B for positioning and torque transmission are provided where the cam ridge is located on the side surface.

The cam 3 engages the notch 1B formed in the housing 1 with the projection 3B, rotates 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 Rotates with the rotor 4 and the cam 3
After rotating until the projection 3B of the housing 1 hits the notch 1B of the housing 1, it rotates integrally with the housing 1. The rotor 4 is rotatably housed in the housing 1, is coupled to the input shaft 5, and rotates integrally 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 a return spring 8 which also functions as a preload mechanism. It is stored freely. Further, a plurality of suction / discharge holes 9 are formed in the rotor 4 so as to communicate with each plunger chamber 6. FIG. 2 shows a valve side surface of the rotor 4.

A plurality of suction / discharge holes 9 are formed in the rotor 4 in the circumferential direction, and each of the suction / discharge holes 9 communicates with the plunger chamber 6. A spline 10 is formed on the inner periphery 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 a suction port 12 and a discharge port 13 are formed. The rotary valve 11 engages a notch 1 </ b> B Is positioned and fixed.

The discharge port 13 communicates with the high-pressure chamber 15, and an orifice 16 is formed at the outlet of the high-pressure chamber 15 as flow resistance generating means. Also, rotary valve 1
1 is provided with a relief hole 17 communicating with the high-pressure chamber 15, 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 front side of the rotary valve 11. In FIG. 3, a plurality of suction ports 12 that open to the outer periphery 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 is formed on the inner diameter side of the suction port 12 and the discharge port 13 and has a bearing pad portion 20 which is flush with the valve surface of the rotary valve 11.

The third port 19 is formed on the end face of the rotor 4 or on the front face 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 open on the back surface of the rotary valve 11. When the oil drain hole 21 is not free, the oil accumulated in the third port 19 is drained. When the oil drain hole 21 is free, the high-pressure oil flows back from the oil drain hole 21 to the third port 19. I have.

Outflow path 2 is provided on the outer periphery of rotary valve 11.
2 is formed, and the discharge oil from the orifice 16 flows out of the outflow passage 22 to the low-pressure chamber in the joint. That is, the oil discharged from the orifice 16 is not caused to flow out to the oil chamber side provided with the movable magnetic body described later by the
I let it flow out to the side. Referring again to FIG.
Reference numeral 3 denotes a retainer provided in contact with the rotary valve 11, and a 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 to prevent oil leakage by the seal ring 25 and to move the retainer 23 rightward in the figure by a stopper ring 26 provided on the inner periphery of the housing 1. To block.

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. Reference numeral 28 denotes a lock valve as a control valve, and the lock valve 28
And slidably inserted into the first groove 27,
The orifice 16 is opened and closed. The lock valve 28 is formed of a rod-shaped member having a conical or spherical shape at the end concentrically arranged with the orifice 16 and having a diameter larger than the diameter of the orifice hole, and directly closes 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.
The third communicating with the relief hole 17 of the rotary valve 11
Groove 30 is formed. Reference numeral 31 denotes a relief valve as a control valve. The relief valve 31 is slidably inserted into the retainer 23, protrudes into the third groove 30, and opens and closes the relief hole 17.

The relief valve 31 is formed of a rod-shaped member having a conical or spherical shape at the end concentrically arranged with the relief hole 17 and having a diameter larger than the relief hole diameter.
Is directly obstructed. The oil drain hole 21 communicating with the third port 19 and the drain hole 18 of the rotary valve 11 also communicate with the third groove 30.

Reference numeral 33 denotes a free valve as a control valve. The free valve 33 is slidably inserted into the retainer 23, protrudes into the third groove 30, and opens and closes the discharge hole 18. The free valve 33 is made of a rod-shaped member having a conical or spherical shape at the end concentrically arranged with the discharge hole 18 and having a diameter larger than the diameter of the discharge hole, and directly closes the discharge hole 18.

Numeral 34 denotes a movable magnetic body that generates a magnetic attraction force by energizing the solenoid coil 35. The movable magnetic body 34 is movably housed in the housing 1. When a weak current flows through the solenoid coil 35, the upper side of the movable magnetic body 34 is attracted to the retainer 23 side, and the lock valve 28 is operated. When a strong current flows through the solenoid coil 35, the movable magnetic body 34 It is sucked to the side 23 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 current is weakly applied to the solenoid coil 35, the upper side of the movable magnetic body 34 is attracted to the retainer 23 side, and the lock valve 28 is operated. On the other hand, when the strong current is applied to the solenoid coil 35, the entire circumference of the movable magnetic body 34 is 23
And the free valve 33 and the relief valve 31 operate. 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, a relief pressure setting spring 38 is interposed. 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 operated, and the relief valve 31 is operated. The hole 17 is opened (see FIG. 10). Thereby, generation of excessive torque can be prevented. 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 flows back through the relief hole 17 and the third groove 30 to the oil drain hole 21 and to the third port 19 (see FIGS. 11 and 12). In FIG. 1 again, 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
Numeral 1 has a function as a stopper for preventing the movable magnetic body 34 from moving rightward, and a fulcrum 39 of the reversing lever 36 is brought into contact therewith.

The inner cover 41 is formed to have a predetermined shape, and regulates 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 for absorbing thermal expansion of the sealed oil,
Air 44 is sealed inside. Inner cover 4
1 is formed with a communication hole 45 so that the sealed oil can enter and exit from the communication hole 45.

Reference numeral 46 denotes a first magnetic frame. The first magnetic frame 46 is fixed to an external member by bolts 47, and is held in a non-contact state with the joint. The first magnetic frame 46 is disposed concentrically with respect to the joint shaft, and the solenoid coil 35 is housed in the first magnetic frame 46. Reference numeral 48 denotes 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 as a whole constitute an actuator for operating the movable magnetic body 34 by an external signal.

Reference numerals 49 and 50 denote oil holes, 51 denotes a seal ring, 52 denotes a needle bearing, and 53 denotes 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, and the relief hole 17 is closed. Further, 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 has the orifice 16 open because there is no attractive force of the movable magnetic body 34. Therefore, the oil flows as indicated by arrow A. That is, the discharge port 1
The oil pushed out to 3 passes through the high-pressure chamber 15 and the orifice 16 and is supplied to the suction port 12 through the outflow passage 22.

Then, due to the resistance of the orifice 16, the hydraulic pressure in the high-pressure chamber 15, the discharge port 13, and the plunger chamber 6 rises, and a reaction force is generated in the plunger 7. By rotating the cam 3 against this plunger reaction force, a torque is generated, and the torque is transmitted between the cam 3 and the rotor 4. The torque characteristic at this time is shown in 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. In the pressure distribution C, the close contact 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 lands 54 and 55.

Next, the lock characteristics will be described. When the solenoid coil 35 is weakly energized, only the upper side of the movable magnetic body 34, on which the return spring 37 is not provided, is attracted to the retainer 23 and presses the lock valve 28 to close the orifice 16 (see FIG. 8). ). On the other hand, since the lower side of the movable magnetic body 34 does not move,
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 due to the load of the relief pressure setting spring 38, and the relief hole 17 remains closed.

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

Next, a description will be given of the discharge of the leak oil in the case of the normal characteristic and the lock characteristic. In the case of the normal characteristic and the lock characteristic, the high-pressure oil in the discharge port 13 leaks through the seal lands 54 and 55, though slightly. In a state where the discharge hole 18 is closed by the free valve 33, the leaked oil accumulates in the third port 19 and lifts the rotor 4 from the valve surface.
In the present embodiment, as shown in FIG.
From 1, through the third groove 30, through the discharge hole 18 and into the suction 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. When the pressure in the high-pressure chamber 15 exceeds a predetermined value determined by the strength of the relief pressure setting spring 38 in the normal characteristic and the lock characteristic, the relief valve 31 moves to the right as shown in FIG. 17 and the reversing lever 36
Is swung to close the free valve 33, but the free valve 33 does not completely close the discharge hole 18. Accordingly, 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 flows from the discharge hole 18 to the suction port 12. Flows.

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 characteristics are as shown by H in FIG. Next, the free characteristics will be described. 11 and FIG. 1 when the solenoid coil 35 is strongly energized.
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.

For this reason, the pressure oil in the high-pressure chamber 15 flows from the relief hole 17 and the third groove 30 to the oil discharge hole 2 as shown by the arrow I.
1 and enters the third port 19. Due to this backflow, the hydraulic pressure 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 close contact between the rotor 4 and the rotary valve 11 is lost.
At this time, the pressure distribution J for moving the rotor 4 to the left is:
It is determined by the discharge port 13, the seal lands 54, 55, the third port 19, and the third port seal land 56.

Therefore, the main flow of oil (arrow K) from the plunger chamber 6 flows out of the gap between the rotor 4 and the rotary valve 11. The torque characteristic at this time is indicated by L in FIG. Next, FIGS.
FIG. 3 is a diagram showing the first embodiment of the present invention described above. FIG.
FIG. 4 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 is opened.
8 is opened by the free valve 33. This results in the joint having normal characteristics. On the other hand, the oil accumulated in the third port 19 is indicated by an arrow M
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 the 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 a locking characteristic. 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 an arrow N. FIG. 15 is an explanatory diagram of the 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 is closed.
The pressure oil flows through the relief hole 17 as shown by the arrow O, flows back to the oil drain hole 21, and enters the third port 19. For this reason, the close contact between the rotor 4 and the rotary valve 11 is lost, and the free characteristics are obtained.

As described above, when the oil is not freed, the oil accumulated in the third port 19 is discharged from the discharge hole 18, so that the close contact between the rotor 4 and the rotary valve 11 can be maintained. Since there is no oil leakage, a decrease in torque can be prevented. Relief valve 3
1 and the free valve 33 are formed of a rod-shaped member having a conical or spherical shape at the tip and a diameter larger than the diameter of the relief hole and the diameter of the discharge hole, so that the sticking hardly occurs and the reliability can be improved.

In the third port 19, the bearing pad 2 is flush with the valve surface of the rotary valve 11.
Since 0 is provided, a large thrust area for receiving a thrust load during normal torque transmission can be obtained, so that 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 becomes simple and the production is simplified.

Further, since the cross-sectional area of the high-pressure chamber 15 may be small, the rotary valve 11 is small, and the cost can be reduced. Next, FIGS. 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, joints exhibit normal properties. On the other hand, the discharge hole 18
Is opened, and 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 P.

FIG. 17 is an explanatory diagram of the lock characteristics. FIG.
At 7, the orifice 16 is closed by a lock valve 28, and the relief hole 17 of the high-pressure chamber 15 is closed by a relief valve 31. Thus, the joint exhibits locking properties. On the other hand, the drain hole 18 is open, and the oil accumulated in the third port 19, as shown by the arrow Q,
Through the discharge hole 18.

FIG. 18 is an explanatory diagram of the free characteristic. FIG.
At 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 backward to the oil drain hole 21 as shown by the arrow R, enters the third port 19, and the state of close contact between the rotor 4 and the rotary valve 11 is lost. Thus, the joint exhibits free characteristics. On the other hand, since the discharge hole 18 is open while having a small diameter, a part of the pressure oil in the high-pressure chamber 15 is discharged from the discharge hole 18 as shown by the arrow S.

In this embodiment, the same effect as in the above embodiment can be obtained. 19 to 21 show a third embodiment of the present invention. In the present embodiment, the orifice 16 and the lock valve 31 are eliminated, and the relief hole 1 is removed.
7 as an orifice 57 and a relief valve 31 as a lock valve 5
8, and the reversing lever 36 is also eliminated.

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

Thus, the joint exhibits normal characteristics. 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 a dotted line U. FIG. 20 is an explanatory diagram of the lock characteristics. In FIG. 20, the orifice 57 is a lock valve 5
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 the arrow V.

FIG. 21 is an explanatory diagram of the free characteristic. FIG.
In FIG. 1, the orifice 57 is opened by the lock valve 58, and the discharge hole 18 is closed by the free valve 33. Accordingly, the pressure oil in the high-pressure chamber 15 flows back through the orifice 57 to the oil drain hole 21 and enters the third port 19 as shown by the arrow X. Thus, the close contact between the rotor 4 and the rotary valve 11 is lost, and the joint exhibits free characteristics.

In this embodiment, the same effects as in the above embodiment can be obtained. Next, FIGS. 22 to 24 are views showing a fourth embodiment of the present invention. In this embodiment, the orifice 16 is the first orifice 59 and the
7 is a 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,
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 an arrow a. Therefore, joints exhibit normal 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 a dotted line b.

FIG. 23 is an explanatory diagram of the lock characteristics. FIG.
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 a free valve 33. Since the second orifice 60 is open, the pressure oil in the high-pressure chamber 15 is discharged through the second orifice 60 as shown by an arrow c, but the first orifice 59 is closed by the lock valve 28. So it is almost in the state of lock. 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 a dotted line d.

FIG. 24 is an explanatory diagram of the free characteristic. FIG.
4, 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 closed by the free valve 33. Accordingly, the pressure oil in the high-pressure chamber 15 is supplied to the second orifice 6 as shown by the arrow e.
0, flows back to 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 rotor 4 becomes free.

In this embodiment, the same effects as in the above embodiment can be obtained.

[0064]

As described above, according to the present invention, when it is not free, oil accumulated in the third port can be drained, and the close contact between the rotor and the valve body can be maintained. Therefore, torque reduction can be prevented. In addition, sticking of the control valve hardly occurs, and 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 be formed in 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 the drawings]

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

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

FIG. 3 is a surface view of a rotary valve.

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

FIG. 5 is an explanatory diagram of a normal characteristic.

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 discharge of leak oil.

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

FIG. 11 is an explanatory diagram of a free characteristic.

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 a free characteristic 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 a free characteristic according to the second embodiment.

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

FIG. 20 is an explanatory diagram of lock characteristics according to the third embodiment.

FIG. 21 is an explanatory diagram of a free characteristic according to the third embodiment.

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

FIG. 23 is an explanatory diagram of a 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: Non-magnetic part of housing 1B: Notch 2: Member 2A: Spline 3: Cam 3A: Cam surface 3B: Projection 4: Rotor 5: Input shaft 6: Plunger chamber 7: Plunger 8: Return spring 9 : Suction and discharge hole 10: Spline 11: Rotary valve (valve element) 12: Suction port 13: Discharge port 14: Projection 15: High pressure chamber 16: Orifice 17: Relief hole 18: Discharge hole 19: Third port 20: Bearing Pad portion 21: Oil drain hole 22: Outflow path 23: Retainer 24: Bearing 25: Seal ring 26: Stopper ring 27: First groove 28: Lock valve (first control valve) 29: Second groove 30: Second 3 groove 31: relief valve (third control valve) 33: free valve (second control valve) 34: movable magnetic body 35: solenoid coil 36: Roller lever 37: return spring 38: relief pressure setting spring 39: fulcrum 41: inner cover 42: cover 43: diaphragm 44: air 45: communication hole 46: first magnetic frame 47: bolt 48: second magnetic frame 49 , 50: Lubrication hole 51: Seal ring 52: Needle bearing 53: Stopper ring 54, 55: Seal land 56: Third port seal land 57: Orifice 58: Lock valve 59: First orifice 60: Second Orifice

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16D 31/02 B60K 17/348

Claims (8)

(57) [Claims] 1. A hydraulic pump provided between an input / output shaft that is rotatable relative to each other and driven by differential rotation of the two shafts; and a control provided at an outlet of the hydraulic pump to control a flow resistance of discharge oil. A valve; an actuator for operating the control valve in response to an external signal; a hydraulic power transmission coupling for transmitting a torque corresponding to a rotational speed difference between the two shafts and an external control signal; 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; A plurality of plungers which are reciprocated while being regulated by the cam with the relative rotation of the cam and the rotor; and A suction and discharge hole communicating with the suction chamber, a valve body provided with a suction port and a discharge port provided in contact with an end face of the rotor and acting as a suction valve and a discharge valve depending on a positional relationship with the suction and discharge hole; A preload mechanism for maintaining close contact between the rotor and the valve element; provided on a valve surface of the valve element;
A third port closed by the end face of the rotor and releasing the close contact between the rotor and the valve body by the pressure when a high pressure state is provided. The third port is provided in the valve body and is made to communicate with the discharge port. A control valve for controlling a conduction state between the third port and the low-pressure chamber in the joint, and a conduction state between the third port and the high-pressure chamber; and a control valve based on an external signal. A hydraulic power transmission coupling, comprising: the actuator for actuating the pressure switch; and wherein the pressure of the third port can be switched between two high and low pressure states. 2. The hydraulic power transmission coupling according to claim 1, wherein said third port is arranged on an inner diameter side of said suction port and said discharge port. 3. The hydraulic power transmission coupling according to claim 1, wherein a bearing pad portion is provided in the third port so as to be flush with the valve surface of the valve element. 4. The hydraulic power transmission coupling according to claim 1, wherein said third port is provided on an end face of the rotor. 5. The hydraulic power transmission coupling according to claim 1, wherein said control valve is constituted by a rod-shaped member having a conical or spherical shape at its tip and a diameter larger than a hole diameter. 6. The hydraulic power transmission coupling according to claim 1, wherein a continuity between said third port and a low-pressure chamber in said coupling is always maintained. 7. The hydraulic power transmission coupling according to claim 1, wherein an orifice provided at an outlet of said hydraulic pump is controlled to open and close by said control valve. 8. The hydraulic power transmission coupling according to claim 7 , wherein a second orifice is provided at an outlet of the hydraulic pump in addition to the orifice, and the second orifice is always opened.