JP2886795B2 - 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 Conventional hydraulic power transmission couplings include, for example, those shown in FIG. 6 and FIG. 6 and 7, reference numeral 1 denotes a rotary valve of a hydraulic power transmission joint. The rotary valve 1 has a high-pressure chamber 2 formed therein, and the high-pressure chamber 2 communicates with a discharge port (not shown). Ball 3 as a valve body in high-pressure chamber 2
Is movably stored, and the ball 3 is normally pressed and held by the pin member 4. The pin member 4 is urged by a spring 6 as an elastic member via a ball 5, and the spring 6 is formed in the rotary valve 1 and housed in a housing hole 7. The pin member 4 is prevented from moving by the pin member 8 via the ball 5. The high-pressure chamber 2 is closed by a plug 9, and an orifice 10 communicating with the low-pressure chamber is opened in the high-pressure chamber 2.

As shown in FIGS. 6 (A) and 6 (B), in a normal state, that is, in a rotation difference region not more than the lock torque, the spring 6 pushes the ball 5 through the ball 5 due to the pressing force of the pin member 4 by the hydraulic pressure of the high pressure chamber 2. Therefore, the pin member 4 presses the ball 3 because the force for pressing the pin member 4 is greater. Therefore, the orifice 10 as the flow resistance generating means is open, and the oil passes through the orifice 10. Arrow a at normal time
As shown by, the force by which the spring 6 pushes the pin member 4 is large. Arrow b indicates the flow of oil through orifice 10.

[0004] Therefore, the torque characteristic in the normal state is shown by c in FIG. In the drawing, Tr indicates a lock torque, and d indicates a rotation difference region equal to or less than the lock torque Tr. On the other hand, as shown in FIGS. 7 (A) and 7 (B), in the rotation difference region equal to or more than the lock torque, the force a1 of pressing the pin member 4 by the hydraulic pressure of the high pressure chamber 2 becomes larger than the force of pressing the pin member 4 by the spring 6. Therefore, the pin member 4 moves, the spring 6 is compressed, the ball 3 becomes free, and the orifice 10
Is closed. The joint is thus locked.

The torque characteristic at this time is a lock characteristic as shown in FIG. At the time of release, a force for pushing the ball 3 is necessary, and the force can be set freely by adjusting the contact position between the orifice 10 and the ball 3 and the contact position between the pin member 4 and the ball 3 in FIG. In order to prevent hunting, it is desirable that the pressure be released after the hydraulic pressure in the high-pressure chamber 2 slightly decreases. That is, at the time of release, the torque T is equal to the lock torque Tr.
The torque Tk is lower than the torque Tk.

Next, FIG. 10 is a diagram showing another conventional example. In FIG. 10, reference numeral 11 denotes a rotary valve of a hydraulic power transmission joint. A high pressure chamber 12 is formed on the front side of the rotary valve 11, and a communication groove 13 communicating with the high pressure chamber 12 is formed on the rear side. . Also, the rotary valve 1
A storage hole 14 is formed in 1, and a ball 15 as a valve body is movably stored in the storage hole 14.

The storage hole 14 and the high-pressure chamber 12 have an orifice 16
And the orifice 16 is spring 17
The spring 17 is closed by the plug 18 and the ball 15 which close the storage hole 14.
It is interposed between. Further, a discharge hole 19 for releasing hydraulic pressure is opened in the storage hole 14. When the oil pressure in the high-pressure chamber 12 rises above a predetermined value, the ball 15 moves against the spring 17 and releases the orifice 16.

Accordingly, the torque characteristic at this time is shown in FIG.
The initial torque is increased by an amount indicated by f in FIG.

[0009]

However, in such a conventional hydraulic power transmission joint, in the case of FIGS. 6 and 7, when the torque becomes constant, the pin member is pushed and the ball is pushed. By closing the orifice, it is possible to obtain the torque characteristics of the auto-lock for improving the performance on rough roads, and in the case of FIG. 10, to improve the vehicle stability such as starting on a low μ road such as snow and cornering. However, it is not possible to simultaneously obtain both the torque characteristics of the auto-lock and the characteristics of the initial torque increase necessary for vehicle performance.

The present invention has been made in view of such a conventional problem. A step portion is provided on a pin member, an orifice is closed in an initial state, and until the hydraulic pressure overcomes the spring force. An object of the present invention is to provide a hydraulic power transmission coupling that can simultaneously obtain an auto-lock torque characteristic and an initial torque increase by preventing oil from passing through an orifice.

[0011]

In order to achieve the above object, the present invention is configured as follows. First, the present invention
A cam housing provided between input / output shafts that are relatively rotatable and connected to one shaft to form a cam surface having two or more ridges on an inner surface; connected to the other shaft and inside the cam housing A rotor having a plurality of plunger chambers formed in the axial direction so as to be rotatable; and a plurality of plunger chambers which are housed in respective plunger chambers so as to be reciprocally movable under the pressure of a return spring. A plurality of plungers driven by a cam surface during rotation; a suction / discharge hole formed in the rotor and communicating with the plunger chamber; rotatably slidably contacting an end face of the rotor and having a predetermined relationship with the cam housing. A rotary valve having a plurality of suction ports and discharge ports formed on the surface thereof, the plurality of suction ports functioning as a suction valve and a discharge valve depending on the positional relationship with the suction and discharge holes; Comprising a flow resistance generating means for generating a flow resistance by the flow of oil discharged by the driving of the changers;
It is intended for a hydraulic power transmission coupling that transmits torque according to the rotational speed difference between both shafts.

According to the present invention, a collar member is provided in a high-pressure chamber formed in a rotary valve and communicated with a discharge port, and a valve member is movably housed in the collar member. The valve body is held by a pin member urged by an elastic member, and a gap between a pin portion of the pin member and a communication hole communicating the inside of the collar member and a storage hole for storing the pin member is used as a flow resistance generating means. And a step portion for closing the orifice is formed following the pin portion.

Further, in addition to the elastic member, a second elastic member for urging the pin member when the pin member moves by a predetermined stroke or more may be provided in the storage hole.

[0014]

According to the hydraulic power transmission coupling of the present invention, the collar member is provided in the high-pressure chamber, the valve body is movably housed in the collar member, and the valve body is biased by the elastic member. While holding with the member, the gap between the pin portion of the pin member and the communication hole communicating the inside of the collar member and the storage hole for storing the pin member is set as an orifice as flow resistance generating means, and a step portion for closing the orifice is provided. In the initial state, the orifice is closed at the step, and the orifice is opened when the hydraulic pressure overcomes the spring force of the elastic member. Therefore, the initial torque increase for improving the vehicle performance and the torque characteristic of the auto-lock can be obtained at the same time.

Further, since the gap between the pin portion of the pin member and the communication hole is an orifice, it is possible to prevent the pin member from being fixed by foreign matter. Further, since the valve body is housed in the collar member, it is possible to prevent the orifice from being damaged by the impact of the valve body during locking. Further, in addition to the elastic member, since the second elastic member that urges the pin member when the pin member moves by a predetermined stroke amount or more is provided in the storage hole, a double spring structure is provided. The point torque value and the initial torque-up torque value can be changed independently. That is, the torque value of the lock point can be freely changed by changing the spring force of the second elastic member.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of the present invention.
FIG. 2 is a sectional view of a joint according to one embodiment of the present invention. First, the structure will be described. In FIG. 2, reference numeral 31 denotes a cam having a cam surface 32 having two or more ridges on an inner surface thereof. The cam 31 is connected to an output shaft (not shown) and rotates integrally with the output shaft. I do. Further, the cam 31 is fixed to the cam housing 34 by a welding portion 33, and the cam 31 is
4 and rotate together.

A rotor 35 is rotatably housed in the cam housing 34. The rotor 35 is connected to an input shaft 36 and rotates integrally with the input shaft 36. A plurality of plunger chambers 37 are formed in the rotor 35 in the axial direction,
A plurality of plungers 38 are slidably accommodated in the plunger chamber 37 via a return spring 39. Further, a plurality of suction / discharge holes 40 are formed in the rotor 35 so as to communicate with each plunger chamber 37.

Reference numeral 41 denotes a suction port 42 and a suction passage 43 on the surface.
And a rotary valve in which a discharge port 44 is formed.
Are formed with a communication groove 45 communicating with each of them. Further, a lid member 46 is provided in close contact with the back surface, and the communication groove 45 is closed. The rotary valve 41 has a positioning projection 48 that engages with a notch 47 formed on the inner periphery of the cam housing 34.

The rotary valve 41 constitutes a timing member for determining the opening / closing timing of the suction / discharge port 40, and the notch 47 and the projection 48 constitute a positioning mechanism for regulating the phase relationship between the cam 31 and the rotary valve 41. . When the plunger 38 is in the suction stroke, there is a positional relationship between the suction port 42 of the rotary valve 41 and the suction / discharge port 40 of the rotor 35, and the orifice, suction port 42, suction path 43, and suction / discharge port of the rotor 35, which will be described later. Oil can be sucked into the plunger chamber 37 through 40.

When the plunger 38 is in the discharge stroke, the relationship is opposite to that of the suction stroke, and the suction and discharge holes 40 of the rotor 35 communicate with the communication groove 45 through the discharge port 44 of the rotary valve 41. Reference numeral 49 denotes a bearing retainer which rotates integrally with the cam housing 34, and supports the input shaft 36 via a bearing 50. A thrust needle bearing 51 is interposed between the bearing retainer 49 and the rotary valve 41, and the friction torque on the thrust needle bearing 51 side is set to be smaller than the friction torque between the rotor 35 and the rotary valve 41. I have. Therefore, when the direction of the differential rotation changes, the rotary valve 41
5 and rotates until the positioning projection 48 of the rotary valve 41 hits the notch 47 of the cam housing 34, and then rotates together with the cam housing 34. Thus, the suction / discharge port 40 is forcibly opened and closed at a predetermined timing even at the time of forward rotation or reverse rotation.

An oil seal 52 is provided between the bearing retainer 49 and the input shaft 36.
An accumulator piston 53 for absorbing thermal expansion and contraction of oil is slidably accommodated in the inside. 54
Is a lid member for preventing infiltration of muddy water into the accumulator chamber 55. The accumulator chamber 55 communicates with the inside of the joint via oil passages 56 and 57.

The rotary valve 41 has the discharge port 4
A high-pressure chamber 58 communicating with 4 is formed, and an outlet of the high-pressure chamber 58 is closed by a plug 59. In addition, 60 is an oiling hole, 61 is a needle bearing, 62 is a screw hole, 6
3 and 64 are O-rings, 65 and 66 are snap rings, 6
7 is a mounting hole. Next, FIG. 1 is a sectional view of an essential part showing one embodiment of the present invention.

In FIG. 1, reference numeral 41 denotes the rotary valve. The rotary valve 41 has a discharge port 44 formed therein. Further, a high-pressure chamber 58 is formed in the rotary valve 41 so as to communicate with the discharge port 44 via a through-hole 68. A collar member 69 is provided in the high-pressure chamber 58, and a plug 59 is screwed in after the collar member 69. I have. The collar member 69 is made of a hardened material, and has a storage chamber 71 in which a ball 70 as a valve body is stored. The storage chamber 71 has an opening 7 formed in the collar member 69.
2 and communicate with the through hole 68 and the discharge port 44.
A valve seat 73 is formed in the storage chamber 71, and when the oil pressure in the storage chamber 71 exceeds a predetermined value, the ball 70 moves rightward in the drawing and sits on the valve seat 73. An opening 74 on the outlet side is formed following the valve seat 73, and a communication hole 75 is formed in the rotary valve 41 following the opening 74.

The communication hole 75 is provided in the storage chamber 71 of the collar member 69.
And a storage hole 77 for storing a pin member 76 for holding the ball 70. The pin member 76 is urged by a spring 78 as an elastic member to press and hold the ball 70. An orifice 80 as a flow resistance generating means is formed in a gap between the communication hole 75 and the pin portion 79 of the pin member 76. Following the pin portion 79 of the pin member 76, the pin portion 79
A step portion 81 having a larger diameter is integrally formed, and a base end portion 82 having a larger diameter than the step portion 81 is integrally formed following the step portion 81. In the initial state, the hydraulic pressure for pushing the pin portion 79 of the pin member 76 rightward is smaller than the urging force of the spring 78, so that the orifice 80 is closed by the step portion 81 of the pin member 76. When the oil pressure rises and exceeds a predetermined value, the ball 70 moves rightward and presses the pin member 76, and the pin member 76 moves rightward against the spring 78, and the orifice 80 is opened. You. When the oil pressure further rises and exceeds a predetermined value, the ball 70 is moved to the valve seat 73.
And the opening 74 is closed, whereby the orifice 80 is closed.

A pin member 83 is stored in the storage hole 77,
When the pin member 76 contacts the pin member 83, the pin member 7
6 is blocked. The storage hole 77 is a stopper pin 84
It is closed by. A drain hole 85 is opened in the storage hole 77 so that oil can escape to the low-pressure chamber side from the drain hole 85. Incidentally, FIG. 1 in a ₁ is communicating hole 75
A ₂ is the area of the pin 79, F is the spring 78
The spring force of each is shown.

Next, the operation will be described. When there is no rotation difference between the cam 31 and the rotor 35, the plunger 3
8 does not work and no torque is transmitted. At this time, the plunger 38 is pressed against the cam surface 32 by the return spring 39. Next, when a rotation difference occurs between the cam 31 and the rotor 35, the plunger 38 in the discharge stroke is pushed in the axial direction by the cam surface 32 of the cam 31.

At this time, the suction / discharge port 40 is connected to the discharge port 44
The plunger 38 pushes the oil in the plunger chamber 37 from the suction / discharge hole 40 to the discharge port 44 of the rotary valve 41. The oil pushed out to the discharge port 44 passes through the through hole 68, the opening 72, the storage chamber 71, the opening 7
4. The storage hole 77 and the drain hole 8 through the orifice 80
5, the air is supplied from the suction passage 43 to the suction port 42.
At this time, the hydraulic pressure in the through hole 68, the opening 72, the storage chamber 71, the discharge port 44, and the plunger chamber 37 increases due to the resistance of the orifice 80, and a reaction force is generated in the plunger 38. By rotating the cam 31 against this plunger reaction force, torque is generated, and the cam 31 and the rotor 3
5 is transmitted. Note that the discharge port 44
Are communicated through the communication groove 45, so that the hydraulic pressures of all the plunger chambers 37 in the discharge stroke become equal.

Further, when the cam 31 rotates, a suction stroke occurs, and the suction / discharge port 40 communicates with the suction port 42, so that the oil in the suction path 43 is discharged from the suction port 42, the suction / discharge port 4
The plunger 38 is sucked into the plunger chamber 37 through 0, and returns along the cam surface 32 of the cam 31. here,
In the initial state, assuming that the oil pressure in the storage chamber 71 is ΔP, (ΔP × a ₁ ) is the spring force F of the spring 78.
Since it is smaller, the orifice 80 is closed by the step 81 of the pin member 76.

The oil pressure ΔP in the storage chamber 71 rises and (ΔP
× a ₁ ) = F 2, an initial torque increase as shown by h in FIG. 3 can be obtained. The oil pressure ΔP rises,
When (ΔP × a ₁ )> F 2, the pin member 76 moves rightward in FIG. 1 and the step portion 81 of the pin member 76 opens the orifice 80. The oil from the discharge port 44
8, the liquid passes through the orifice 80 through the opening 72, the storage chamber 71, and the opening 74, and is supplied to the low-pressure chamber through the storage hole 77 and the drain hole 85.

The torque characteristic at this time is proportional to the square of the differential rotation speed ΔN as shown in FIG. The oil pressure ΔP in the storage chamber 71 further increases, and (ΔP × a ₂ ) + α = F + kδ where α is the resistance in the flow path of the ball 70 k is the spring constant of the spring 78 δ is the stroke amount of the pin member 76 (of the spring 78 (Compression amount), the pin member 76 further moves rightward in the figure,
Since the ball 70 is seated on the valve seat 73 by the resistance force α in the flow path, the orifice 80 is closed.

The torque characteristic at this time is a lock characteristic as shown in FIG. Further, when the oil pressure ΔP rises and (ΔP × a ₂ ) + α> F + kδ, the pin member 76 comes into contact with the pin member 83, and further movement to the right is prevented. Thus, the lock is completed. The torque characteristic after the lock is completed is shown by k in FIG.

As described above, both the torque characteristics of the automatic lock and the torque characteristics of the initial torque increase can be obtained at the same time. Further, since the gap between the pin portion 79 and the communication hole 75 is defined as the orifice 80, the pin member 76 does not adhere to the foreign material. Further, the valve seat 73 is formed in the collar member 69, and the ball 70 is seated on the valve seat 73 to close the opening 74, thereby closing the orifice 80. The orifice 80 does not break.

FIG. 4 is a cross-sectional view of a principal part showing another embodiment of the present invention. In FIG. 4, reference numeral 41 denotes a rotary valve, and a storage hole 77 is formed in the rotary valve 41. The storage hole 77 communicates with the storage chamber 71 of the collar member 69 via the communication hole 75. A gap between the communication hole 75 and the pin portion 79 of the pin member 76 is an orifice 80. A first spring 78 as an elastic member, a second spring 86 as a second elastic member, and a pin member 83 are accommodated in the accommodation hole 77.

The first spring 78 urges the pin member 76, and the pin member 76 holds the ball 70. The second spring 86 urges the pin member 76 leftward when the pin member 76 moves rightward by a predetermined stroke amount δ or more. The pin member 83 comes into contact when the pin member 76 moves further rightward, and prevents further movement to the right.

A step 81 is formed integrally with the pin 79 of the pin member 76, and the step 81 closes the orifice 80 until the initial torque is increased. Pin member 7
6, a base end portion 82 is formed integrally with the step portion 81. Stroke in the drawing δ pin member 76 the area of (the amount of compression of the first spring 78), a ₁ is the communication hole 75, a
₂ shows the area of the pin portion 79, F ₁ is the spring force of the first spring 78, F ₂ the spring force of the second spring 86 respectively.

In the initial state, (ΔP × a ₁ ) <F
_Since it is ₁ , the pin member 76 does not move rightward, and the orifice 80 is closed by the step 81 of the pin member 76. The hydraulic pressure ΔP rises and (ΔP × a ₁ ) = F ₁
, An initial torque increase as shown in FIG. Further, the hydraulic pressure ΔP rises and (ΔP × a ₁ )
> Becomes the F _1, the pin member 76 is first spring 7
8 moves rightward, and the orifice 80 is opened. The oil from the discharge port 44 passes through the orifice 80 through the through hole 68, the opening 72 of the collar member 69, the storage chamber 71, and the opening 74, and is supplied to the low-pressure chamber through the storage chamber 77 and the drain hole 85. (See FIG. 1). The torque characteristic at this time is as shown in FIG.

Furthermore, the hydraulic pressure is raised, at the spring constant of _{(ΔP × a 2) + α} = F 1 + kδ + F 2 α is the flow passage resistance k of the ball 70 is first spring 78, the pin member 76 Further, the ball 70 moves to the right by the stroke amount δ, the ball 70 moves to the right due to the resistance α in the flow path, sits on the valve seat 73, and the orifice 80 is closed.

The torque characteristic at this time is a lock characteristic as shown by l in FIG. In this case, the auto-lock torque value can be made variable. That is, since the first spring 78 and the second spring 86 are provided to form a double spring structure, the torque value at the lock point and the initial torque-up torque value can be changed independently.

The hydraulic pressure ΔP further rises to (ΔP ×
a ₂ ) When + α> F ₁ + kδ + F ₂ , the pin member 7
6 further moves to the right, contacts the pin member 83,
Movement is blocked. The torque characteristic at this time is represented by k in FIG.
It will be something like shown below. In this embodiment, the torque characteristics of the initial torque increase and the automatic lock can be obtained at the same time, and the initial torque increase torque value and the lock point torque value can be changed independently.
That is, by changing the spring force F2 of the _second spring 86, the torque value of the auto lock can be changed.

In this embodiment, the pin member 76 is also provided.
The orifice 80 is not damaged by the impact of the ball 70 during locking.

[0041]

As described above, according to the present invention, it is possible to simultaneously obtain the auto-lock torque characteristics and the initial torque increase necessary for vehicle performance. Further, it is possible to prevent the pin member from being fixed by foreign matter, and to prevent the orifice from being damaged due to the impact of the valve body during locking.

In another embodiment, the torque value of the lock point and the torque value of the initial torque increase can be changed independently.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a joint.

FIG. 3 is a graph showing torque characteristics.

FIG. 4 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is a graph showing torque characteristics of FIG. 4;

FIG. 6 is a diagram showing a conventional example in a normal state.

FIG. 7 is a diagram showing a conventional example at the time of locking.

FIG. 8 is a graph showing torque characteristics in a normal state;

FIG. 9 is a graph showing torque characteristics at the time of locking.

FIG. 10 is a diagram showing another conventional example.

11 is a graph showing the torque characteristics of FIG.

[Explanation of symbols]

 31: Cam 32: Cam surface 33: Welded part 34: Cam housing 35: Rotor 36: Input shaft 37: Plunger chamber 38: Plunger 39: Return spring 40: Suction / discharge hole 41: Rotary valve 42: Suction port 43: Suction path 44: Discharge port 45: Communication groove 46: Lid member 47: Notch 48: Projection 49: Bearing retainer 50: Bearing 51: Thrust needle bearing 52: Oil seal 53: Accumulator piston 54: Lid member 55: Accumulator chamber 56 , 57: oil passage 58: high pressure chamber 59: plug 60: lubrication hole 61: needle bearing 62: screw hole 63, 64: O-ring 65, 66: snap ring 67: mounting hole 68: through hole 69: collar member 70: Ball (valve element) 71: Storage chamber 72, 74: Opening 73: valve seat 75: communication hole 76, 83: pin member 77: storage hole 78: spring (elastic member) 79: pin portion 80: orifice (flow resistance generating means) 81: step portion 82: base end portion 84: stopper Pin 85: drain hole 86: second spring (second elastic member)

Claims (2)

(57) [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 collar member is provided in a high-pressure chamber formed in the rotary valve and communicating with the discharge port, a valve body is movably housed in the collar member, and the valve body is urged by an elastic member. While being held by the pin member, a gap between the pin portion of the pin member and a communication hole communicating the inside of the collar member and the storage hole for storing the pin member is defined as an orifice as the flow resistance generating means, and the orifice is closed. A hydraulic power transmission joint, wherein a step portion is formed following the pin portion. 2. A storage device according to claim 1, wherein a second elastic member for urging the pin member when the pin member moves by a predetermined stroke or more is provided in the housing hole in addition to the elastic member. 2. The hydraulic power transmission coupling according to 1.