JP5053052B2 - Piston device and hydraulic cylinder device provided with the same - Google Patents

Description

  The present invention relates to a piston device and a hydraulic cylinder device including the same.

  2. Description of the Related Art Conventionally, a piston device that operates by hydraulic pressure is used to switch a clutch of a power connection portion of an automatic transmission (AT) such as an automobile. In this type of piston device, a metal annular piston that is normally slidable in the axial direction in the cylinder case and urged away from the clutch plate by a return spring is used as a clutch by hydraulic pressure. It is configured to move to the plate side and press the clutch plate.

FIG. 2 is a cross-sectional explanatory view of a hydraulic cylinder device 51 provided with such a conventional piston device. Since the hydraulic cylinder device shown in FIG. 2 and FIG. 1 to be described later has a substantially rotationally symmetric structure around the rotation axis, only one side (right side) is shown in FIGS.
The hydraulic cylinder device 51 includes a piston 54 that is slidably mounted in an axial direction in an annular space 53 formed in a cylinder case 52. The annular space 53 includes an outer annular space 53a formed on the radially outer side (right side in FIG. 2) of the cylinder case 52, and an inner annular space 53b formed on the radially inner side (left side in FIG. 2) of the cylinder case 52. The outer annular space 53 a and the inner annular space 53 b are partitioned by an annular partition wall 55.

The piston 54 is formed by integrally machining an annular metal member so as to be integrally formed, and an outer portion 54a disposed in the outer annular space 53a and the inner annular space 53b. And an inward portion 54b.
An annular convex portion 56 is formed on the inner peripheral surface of the inner portion 54b, and an annular seal member 57 made of rubber is vulcanized and bonded to the convex portion 56. The seal member 57 has a seal lip that contacts the inner wall surface of the cylinder case 52. An annular groove 58 is formed on the outer peripheral surface of the inner portion 54 b, and an O-ring 59 that contacts the inner peripheral surface of the annular partition wall 55 is disposed in the groove 58. On the other hand, an annular groove 60 is formed on the inner peripheral surface of the outer portion 54 a, and an O-ring 61 that contacts the outer peripheral surface of the annular partition wall 55 is disposed in the groove 60. An annular seal member 62 made of rubber is vulcanized and bonded to the outer peripheral surface of the outer portion 54a.

A first hydraulic chamber is formed in the inner annular space 53b by the inner portion 54b of the piston 54 and the inner wall surface of the cylinder case 52. The outer portion 54a of the piston 54 and the inner wall surface of the cylinder case 52 form the outer side. A second hydraulic chamber is formed in the annular space 53a. The first hydraulic chamber is sealed by the seal member 57 and the O-ring 59, and the second hydraulic chamber is sealed by the seal member 62 and the O-ring 61. A first oil passage 63 communicates with the first hydraulic chamber, and a second oil passage 64 communicates with the second hydraulic chamber. The hydraulic oil is supplied to the first hydraulic chamber and the second hydraulic chamber through the first oil passage 63 and the second oil passage 64, and the hydraulic oil is discharged from the first hydraulic chamber and the second hydraulic chamber. . The piston 54 is slid in the axial direction in accordance with the hydraulic control for the hydraulic chamber. In FIG. 2, 65 is a contact with the ring pressure plate under surface of the outer portion 54 a of the piston 54, the piston 54 is a direction away from the clutch by the return spring 66 through the pressing plate 65 It is biased in a direction (upward in FIG. 2). Although not shown, the pressing plate 65 includes a pressing member extending along the axial direction, and the tip of the pressing member is moved to a multi-plate clutch (not shown) according to the movement of the piston 54. ) Can be pressed.

  However, since the piston 54 in the hydraulic cylinder device 51 is manufactured by cutting out each of the annular metal members one by one, it takes time for processing and increases the cost. Moreover, since it is a solid member, there is a problem that the weight is increased and the occupied space is large because it is processed as an integral body.

  In addition, an O-ring is used to seal the hydraulic chamber. However, in order to mount this O-ring, it is necessary to form an annular groove on the peripheral surface of the piston 54, which is troublesome. Further, the piston 54 needs to have a certain thickness in order to form such an O-ring mounting space (annular groove), and cannot be made compact and thin. Furthermore, the O-ring has a larger sliding resistance than the seal lip, and cannot be slid smoothly depending on the surface roughness of the mating member to be slid, and a stable response cannot be obtained. In order to smoothly slide the O-ring, it is necessary to reduce the surface roughness of the counterpart member, which is a factor for further cost increase.

  The present invention has been made in view of such circumstances, and a piston device capable of reducing the sliding resistance and improving the responsiveness while reducing the weight and size, and the hydraulic cylinder including the piston device. The object is to provide a device.

A piston device according to the present invention includes a piston that is slidably mounted in an annular space formed in an inner space of a cylinder case, an annular first hydraulic chamber that communicates with a first oil passage, and a second oil passage. A piston device that is used in a hydraulic cylinder device that includes an annular second hydraulic chamber that is provided concentrically with the first hydraulic chamber, and that slides the piston in the axial direction in accordance with hydraulic control for these hydraulic chambers. Because
An annular movable member constituting the piston and the cylinder case are fixed, and a part of the movable member is overlapped in the radial direction to form the second hydraulic chamber with the movable member. A fixing member,
The movable member includes a first pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the first hydraulic chamber, a second pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the second hydraulic chamber, and an axial direction. A central cylindrical portion extending to connect the first pressure receiving portion and the second pressure receiving portion, and including a piston ring integrally formed by pressing a metal plate;
The fixing member has a communication hole for communicating the hydraulic front chamber and the second hydraulic chamber in the annular space where the second oil passage opens , and the whole is integrally formed by pressing a metal plate. With a fixed ring,
The first hydraulic chamber and the second hydraulic chamber are sealed by annular seals provided on the piston ring and the fixed ring.

  The piston device of the present invention comprises an annular movable member constituting the piston, and a fixed member that is fixed to the cylinder case and arranged to partially overlap the movable member in the radial direction. The piston ring and the fixed ring constituting the movable member and the fixed member are integrally formed by pressing a metal plate, respectively. In this way, the members or elements that make up the piston device are formed by pressing a metal plate, so the processing is simple and the cost is greatly reduced compared to conventional pistons that have been machined out of metal members. Can be achieved. Further, since the metal plate is formed into a predetermined cross-sectional shape, weight reduction can be achieved.

Further, since the hydraulic chamber is sealed with an annular seal, there is no need to form a groove for mounting such as an O-ring. As a result, the piston device can be made compact and thin.
Furthermore, since the annular seal has a smaller sliding resistance than the O-ring and can slide smoothly on the sliding surface, a stable response can be obtained. In addition, in the present invention, the ring-shaped seal slides on the surface of the fixed ring that has been pressed. The press surface of the fixed ring has a small surface roughness even without any post-processing. Since it is a surface, slidability can be further improved. In other words, a good sliding surface can be obtained without processing the sliding member.

  The hydraulic cylinder device according to the present invention is characterized in that, in the hydraulic cylinder device, the piston device is a bonded piston seal that presses a multi-plate clutch of an automatic transmission with the piston.

  According to the piston device of the present invention and the hydraulic cylinder device including the piston device, it is possible to reduce the weight and the size of the device, and to reduce the sliding resistance and improve the response.

Hereinafter, embodiments of a piston device of the present invention and a hydraulic cylinder device including the piston device will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional explanatory view of a hydraulic cylinder device S provided with a piston device P according to an embodiment of the present invention. The hydraulic cylinder device S includes an annular movable member 4 that constitutes a piston that is slidably mounted in the annular direction in an annular space 3 formed inside the cylinder case 2. The annular space 3 includes an outer annular space 3a formed on the radially outer side (right side in FIG. 1) of the cylinder case 2, and an inner annular space 3b formed on the radially inner side (left side in FIG. 1) of the cylinder case 2. The outer annular space 3 a and the inner annular space 3 b are partitioned by an annular partition wall 5.

  The movable member 4 includes a piston ring 4a integrally formed by pressing a metal plate. Seal members 6 and 7 made of rubber are provided near the inner peripheral end and the outer peripheral end of the piston ring 4a, respectively. It is vulcanized and bonded. The piston ring 4a includes an inner flat portion 4a1 disposed in the inner annular space 3b, an outer flat portion 4a2 disposed in the outer space 3a, and a central flat portion 4a3 positioned between the two flat portions, An inner cylindrical portion 4a4 that connects the outer peripheral end of the inner flat portion 4a1 and the inner peripheral end of the central flat portion 4a3, and an outer cylindrical portion 4a5 that connects the inner peripheral end of the outer flat portion 4a2 and the outer peripheral end of the central flat portion 4a3. It consists of and.

  A fixing member 8 is press-fitted into the outer annular space 3a. The fixed member 8 includes a fixed ring 8a integrally formed by pressing a metal plate in the same manner as the piston ring 4a. The inner peripheral surface and the outer peripheral surface of the fixed ring 8a are each made of rubber. The seal members 9 and 10 are vulcanized and bonded. The fixed ring 8a includes an inner flat portion 8a1 that faces the lower end surface 5a of the partition wall 5 (an end surface positioned on the lower side in FIG. 1), an outer flat portion 8a2 that is locked to the cylinder case 2, and a space between the two flat portions. The central flat portion 8a3 positioned at the inner periphery, the inner cylindrical portion 8a4 connecting the outer peripheral end of the inner flat portion 8a1 and the inner peripheral end of the central flat portion 8a3, the inner peripheral end of the outer flat portion 8a2, and the outer periphery of the central flat portion 8a3 It is comprised by the outer side cylinder part 8a5 which connects an end.

Since the piston ring 4a and the fixed ring 8a are integrally formed by pressing a metal plate, the processing is simple, and the cost is much higher than that of a conventional piston that is obtained by machining a metal member. You can go down. Further, since the metal plate is formed into a predetermined cross-sectional shape, weight reduction can be achieved.
In the central flat portion 8a3 of the stationary ring 8a, a plurality of communication holes 11 are formed at equal intervals along the circumferential direction. The diameter of the communication hole 11 is about 2 to 4 mm, and the number thereof is not particularly limited, but about 3 to 8 is a standard.

  The seal member 6 has a seal lip that comes into contact with the inner wall surface of the cylinder case 2, and the seal member 7 has a seal lip that comes into contact with the inner peripheral surface of the outer cylindrical portion 8a5 of the stationary ring 8a. The seal member 9 has a seal lip that comes into contact with the outer peripheral surface of the inner cylindrical portion 4a4 of the piston ring 4a, and the seal member 10 has a hemispherical convex portion that comes into contact with the inner wall surface of the cylinder case 2. Have.

  A first hydraulic chamber 12 is formed in the inner space 3 b by the inner flat portion 4 a 1 and inner cylinder portion 4 a 4 of the piston ring 4 a and the inner wall surface of the cylinder case 2. The fixed ring 8a is disposed so as to partially overlap the piston ring 4a in the radial direction, and the second hydraulic chamber 13 is formed by the overlapping piston ring 4a and fixed ring 8a. Has been. The first hydraulic chamber 12 is sealed by the seal member 6 and the seal member 9, and the second hydraulic chamber 13 is sealed by the seal member 7, the seal member 9, and the seal member 10. A first oil passage 14 communicates with the first hydraulic chamber 12, and a second oil passage 15 communicates with the second hydraulic chamber 13 via a hydraulic front chamber 20. The hydraulic oil is supplied to the first hydraulic chamber 12 and the second hydraulic chamber 13 through the first oil passage 14 and the second oil passage 15, respectively, and the hydraulic oil is supplied from the first hydraulic chamber 12 and the second hydraulic chamber 13. Is discharged.

In the present embodiment, the first hydraulic chamber 12 and the second hydraulic chamber 13 are sealed only by the annular seal members 6, 7, 9 and 10, and no O-ring is used. Therefore, it is not necessary to form a groove in the piston that is necessary for mounting the O-ring. As a result, the piston device can be made compact and thin.
Furthermore, since the seal lip of the seal member has a smaller sliding resistance than the O-ring and can slide smoothly on the sliding surface, a stable response can be obtained. Moreover, in the present embodiment, the seal lip of the seal member 7 slides on the surface of the fixed ring 8a that has been pressed. The press surface of the fixed ring 8a is not particularly required to be post-processed. Since the sliding surface has a small surface roughness, the slidability can be further improved.

  The inner flat portion 4a1 of the piston ring 4a constitutes a first pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the first hydraulic chamber 12, and the central flat portion 4a3, the outer flat portion 4a2 of the piston ring 4a, and The outer cylinder portion 4a5 constitutes a second pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the second hydraulic chamber 13. And inner cylinder part 4a4 comprises the central cylinder part which extends in an axial direction and connects the 1st receiving pressure part and the 2nd receiving pressure part.

In FIG. 1, 16 is an annular pressing plate that contacts the lower surface of the central flat portion 4a3 of the piston ring 4a (the lower surface in FIG. 1, the surface in the advance direction of the piston ring 4a). 4a, that is, the movable member 4 is biased by the return spring 17 through the pressing plate 16 in a direction away from the clutch (upward in FIG. 1). A plurality of return springs 17 are arranged at equal intervals along the circumferential direction. Reference numeral 18 denotes a stopper for restricting the movement position (end point) of the movable member 4 urged in the direction away from the clutch by the return spring 17 to the fixed member 8 side. The stopper 18 is provided on the piston ring 4a. The upper surface of the inner flat part 4a1 is provided with a plurality at equal intervals along the circumferential direction.
The pressing plate 65 includes a pressing member (not shown) extending along the axial direction, and the tip of the pressing member is a clutch of a multi-plate clutch (not shown) according to the movement of the piston 54. The plate can be pressed.

The hydraulic cylinder device S having the above-described configuration operates as follows, for example.
When the hydraulic oil is supplied from the second oil passage 15, the hydraulic oil first enters the hydraulic front chamber 20, and then passes through the communication hole 11 formed in the central flat portion 8a3 of the stationary ring 8a to enter the second hydraulic chamber 13. Flow into. The hydraulic front chamber 20 and the second hydraulic chamber 13 are sealed by the seal lips of the seal members 7, 9 and 10 described above, and the hydraulic front chamber 20 and the second hydraulic chamber 13 are filled with hydraulic oil. The movable member 4, which is a piston, slides in the axial direction and presses the pressing plate 65 against the urging force of the return spring 17.

Then, in a state where the second hydraulic chamber 13 is pressurized, the hydraulic oil is further supplied from the first oil passage 14 to the first hydraulic chamber 12 and is sealed by the seal lips of the seal members 6 and 9. When the chamber 12 is filled with hydraulic oil, the movable member 4 that is a piston slides in the axial direction and is pressed against the urging force of the return spring 17 by the hydraulic pressure of the hydraulic oil in the first hydraulic chamber 12. The plate 65 is pressed. That is, in the present embodiment, in addition to the pressure from the second hydraulic chamber 13, the pressure from the first hydraulic chamber 12 is pressed against the pressing plate 65, so that a larger pressing force can be obtained.
When the pressing plate 65 moves in the axial direction, the tip of the pressing member attached to the pressing plate 65 presses the clutch plate of the multi-plate clutch and presses it, thereby transmitting the driving force.

It is a section explanatory view of a hydraulic cylinder device provided with one embodiment of a piston device of the present invention. It is sectional explanatory drawing of the hydraulic cylinder apparatus provided with the conventional piston apparatus.

Explanation of symbols

2 cylinder case 3 annular space 3a outer annular space 3b inner annular space 4 movable member (piston)
4a Piston ring 6 Seal member 7 Seal member 8 Fixed member 8a Fixed ring 9 Seal member 10 Seal member 11 Communication hole 12 First hydraulic chamber 13 Second hydraulic chamber 14 First oil passage 15 Second oil passage 16 Press plate 17 Return spring P Piston device S Hydraulic cylinder device

Claims (2)

A piston which is slidably mounted in an annular space in an annular space formed inside the cylinder case, an annular first hydraulic chamber communicating with the first oil passage, and the first hydraulic chamber communicating with the second oil passage An annular second hydraulic chamber provided concentrically with the piston chamber, and a piston device used in a hydraulic cylinder device that slides the piston in the axial direction according to hydraulic control on these hydraulic chambers,
An annular movable member constituting the piston and the cylinder case are fixed, and a part of the movable member is overlapped in the radial direction to form the second hydraulic chamber with the movable member. A fixing member,
The movable member includes a first pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the first hydraulic chamber, a second pressure receiving portion that receives the hydraulic pressure of the hydraulic oil supplied to the second hydraulic chamber, and an axial direction. A central cylindrical portion extending to connect the first pressure receiving portion and the second pressure receiving portion, and including a piston ring integrally formed by pressing a metal plate;
The fixing member has a communication hole for communicating the hydraulic front chamber and the second hydraulic chamber in the annular space where the second oil passage opens , and the whole is integrally formed by pressing a metal plate. With a fixed ring,
The piston device, wherein the first hydraulic chamber and the second hydraulic chamber are sealed by annular seals provided on the piston ring and the fixed ring.   The hydraulic cylinder device according to claim 1, wherein the piston device according to claim 1 is a bonded piston seal that presses a multi-plate clutch of an automatic transmission with the piston.

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