JPH1137299A - Sealing device of reciprocating member, and vehicular hydraulic brake device provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device for reliably preventing accumulation of pressure in an intermediate chamber between a pair of seal members in relation to a reciprocating member and for suitably maintaining the pressure accumulation preventing effect, and a vehicular hydraulic brake device provided with the sealing device. SOLUTION: A holding member (a sleeve 17) is interposed between a reciprocating member (a piston 12) and a main body (a cylinder body 1h), and first and second seal members 18a, 18b are held to it. Communication passages 17e, 1d for communicating an intermediate chamber Rm between the first and second seal members to be brought into communication the reciprocating member with a fluid chamber (a power chamber R1) are formed, a one-way sealing means (a third seal member 18c) for stopping pressure transmission from the fluid chamber side to the intermediate chamber side and allowing pressure transmission in the reverse direction is arranged on the communication passage, and an accumulated pressure discharging path different from a high pressure fluid introducing path is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for a reciprocating member, and a hydraulic brake device for a vehicle provided with the sealing device, and more particularly, to a reciprocating member partially exposed to a high-pressure fluid chamber. The present invention relates to a sealing device for sealing and a vehicle hydraulic brake device incorporating the sealing device.

[0002]

2. Description of the Related Art In recent years, hydraulic devices, hydraulic brake devices for vehicles, and the like are provided with sealing devices provided with various sealing members. In particular, sealing of a high-pressure fluid to a reciprocating member is an important issue. And tight sealing conditions are imposed. Regarding such a sealing device, for example, the third edition of Vol. 27, No. 7 (published in November 1996) of "Hydraulic and Pneumatic" magazine
From page 0 to page 36, a high-pressure seal is illustrated, entitled "Trends in High-Pressure Cylinder Seals". In the same magazine, as a form of self-sealing seal of reciprocating seal,
A squeeze-type seal (double-pressure seal) and a lip-type seal are illustrated. In a high-pressure sealing system, these seals are combined and the one shown in FIG. 5 is proposed.

In the high-pressure sealing system for the rod M shown in FIG. 5, a squeeze-type O-ring S1 is used as a primary seal disposed on the pressure side (left side in FIG. 5).
And a combination seal composed of a sliding surface seal B1 and
Lip type U packing S2 and backup ring B as a secondary seal for sealing the oil film that has passed through the primary seal
2 is used. In addition, it is described that the sealing performance of the combination seal is directional with respect to the prevention of pressure accumulation between the primary seal and the secondary seal.

Various types of sealing devices are also used in a vehicle hydraulic brake device.
No. 124505 discloses a sealing device shown in FIG. FIG. 6 shows a support portion of the power piston P with respect to the housing H. Since this portion is adjacent to the power pressure chamber R1 and is exposed to high pressure, an O-ring Sa of the primary seal and a cup of the secondary seal are provided. The seal Sb is combined. The intermediate chamber between the O-ring Sa in contact with the power piston P and the cup seal Sb forms a communication passage A.
Through the reservoir (not shown in FIG. 6).

[0005]

The above "hydraulic and pneumatic"
In the high pressure sealing system described in
Although it is intended to prevent the accumulation of pressure in the middle (chamber) between the primary seal and the secondary seal, the change in the cross-sectional shape of the sliding surface seal B1 alone can be applied to, for example, a vehicle hydraulic brake device. It is difficult to prevent the accumulation of pressure during the period. In particular, since the space between the sliding surface seal B1 and the rod M is used for both the introduction and discharge of pressure to the intermediate chamber between the primary seal and the secondary seal, the application site is inevitably limited. Limited. In addition, due to the wear of the sliding surface seal B1, it is not possible to expect directivity in the sealing property, and the desired pressure accumulation preventing effect may not be maintained.

Therefore, it is desirable to provide a pressure accumulation discharge path separately from the introduction path of the high-pressure fluid, as in the sealing device used in the vehicle hydraulic brake device described in the above-mentioned publication. It is necessary to connect the intermediate chamber between the seal and the low pressure section. However, as shown in FIG. 6, in order to connect to the low pressure section through the communication path A,
Complicated processing is required, and in a structure in which processing is performed directly on the housing H, an increase in the size of the hydraulic brake device is inevitable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sealing device for a reciprocating member in which a pressure accumulation in an intermediate chamber between a pair of sealing members can be reliably prevented and a pressure accumulation preventing effect can be appropriately maintained. And

It is another object of the present invention to provide a vehicle hydraulic brake device having a high-pressure sealing device which has a simple structure, is easy to manufacture, and can be miniaturized.

[0009]

In order to achieve the above object, the present invention provides a body defining a fluid chamber, a reciprocating support for the body, and a part of the body being exposed to the fluid chamber. A reciprocating member for supporting the fluid chamber and pressure adjusting means for selectively adjusting at least a low pressure state and a high pressure state in the fluid chamber in accordance with the reciprocating motion of the reciprocating member. A reciprocating member sealing device comprising a first seal member and a second seal member arranged side by side at a predetermined distance along a reciprocating axis on a supporting portion of the reciprocating member on the main body of the reciprocating member; A holding member interposed between the member and the main body, the holding member holding the first seal member and the second seal member, and the first seal member contacting the reciprocating member; An intermediate chamber between the first and second seal members is connected to the fluid chamber. A holding member that forms a communication passage that communicates with the communication passage, and that prevents pressure transmission from the fluid chamber side to the intermediate chamber side and allows pressure transmission from the intermediate chamber side to the fluid chamber side. And one-way sealing means.

The one-way sealing means is configured to prevent the communication passage from transmitting pressure from the fluid chamber side to the intermediate chamber side and to allow pressure transmission from the intermediate chamber side to the fluid chamber side. It can be constituted by an arranged seal member, for example, a cup seal. Alternatively, the one-way sealing means may be constituted by a check valve interposed in the communication passage.

Further, according to the present invention, a master piston is reciprocally supported in a cylinder body, a pressure chamber is formed in front of the master piston, and a power chamber is formed in a rearward direction. Connecting the pressure chamber and the power chamber to a reservoir for storing brake fluid,
A master cylinder for driving the master piston forward in response to the operation of the brake operating member to output brake fluid pressure from the pressure chamber, and for boosting brake fluid in the reservoir to a predetermined pressure to output power fluid pressure An auxiliary hydraulic pressure source, a control piston disposed reciprocally in front of the master piston in the cylinder body, and arranged to interlock with the master piston, and an output power hydraulic pressure of the auxiliary hydraulic pressure source. Pressure regulating valve means for introducing the fluid into the pressure chamber and regulating the pressure to a predetermined pressure in accordance with the movement of the control piston, and applying the brake fluid pressure regulated by the pressure regulating valve means to the power chamber to assist the master piston. In the vehicle hydraulic brake device, a sleeve interposed between the master piston and the cylinder body is provided along a reciprocating axis of the master piston. The first seal member and the second seal member are juxtaposed and held at a predetermined distance from each other, and an intermediate chamber between the first seal member and the second seal member in contact with the master piston is formed. A sleeve forming a communication passage communicating with the power chamber; and a sleeve disposed in the communication passage, for preventing pressure transmission from the power chamber side to the intermediate chamber side and for preventing pressure from flowing from the intermediate chamber side to the power chamber side. A sealing device having a one-way sealing means allowing transmission can be provided.

Also in this hydraulic brake device, the one-way sealing means prevents the communication passage from transmitting pressure from the power chamber side to the intermediate chamber side, and from the intermediate chamber side to the fluid chamber side. A seal member, for example, a cup seal arranged to allow the pressure transmission. Alternatively, the one-way sealing means may be constituted by a check valve interposed in the communication passage.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a sealing device applied to a hydraulic brake device of the present invention. A power chamber R1 serving as a fluid chamber is provided in a cylinder body 1h serving as a main body of the present invention.
The piston 12 as a reciprocating member is supported so as to be able to reciprocate with respect to the cylinder body 1h and to be partially exposed to the power chamber R1. Further, a regulator (omitted in FIG. 1) described later is provided as the pressure adjusting means and the pressure regulating valve means, and the power chamber R1 is selectively adjusted to at least a low pressure state and a high pressure state according to the reciprocating motion of the piston 12. It is configured to be. That is, piston 1
The power chamber R1 is configured to communicate with a high-pressure regulator or a low-pressure reservoir (to be described later, not shown) via a communication passage 1t between the cylinder body 1 and the cylinder body 1h. A sleeve 17 as a holding member is interposed between the piston 12 and the cylinder body 1h.

The sleeve 17 is a cylindrical member having two annular grooves 17a and 17b formed on the inner surface and two annular grooves 17c and 17d formed on the outer surface. A first seal member 18a and a second seal member 18b are accommodated in the annular grooves 17a and 17b, and these are arranged along a reciprocating axis of the piston 12 (represented by a bidirectional arrow in the drawing). They are juxtaposed at a distance. Then, the first seal member 18a and the second seal member 18b which are in contact with the piston 12
A communication passage 17e is formed in the radial direction of the sleeve 17 so that the intermediate chamber between the power supply chamber R1 and the intermediate chamber communicates with the power chamber R1.
A communication passage 1d is formed by a gap between the sleeve 17 and the cylinder body 1h. Second seal member 18
b is a so-called cup seal having a U-shaped cross section, and corresponds to the above-mentioned lip seal.

Further, as a one-way sealing means, in this embodiment, a third seal member 18c is housed in the annular groove 17c, and one end is disposed so as to close the communication passage 1d.
The third seal member 18c is also a cup seal having a U-shaped cross section, and is provided from the power chamber R1 side to the first seal member 18c.
The pressure transmission to the intermediate chamber Rm side between the second sealing member 18a and the second seal member 18b is prevented, and the pressure transmission in the opposite direction is allowed. Note that, in FIG.
e (annular groove 17d on the second seal member 18b side)
, A fourth seal member 18d is provided. Also,
A sliding surface seal 18e is provided between the first seal member 18a and the piston 12, and a backup ring 18f is provided between the second seal member 18b and the sleeve 17.

According to the sealing device according to the embodiment shown in FIG. 1, the piston 12 reciprocates with respect to the cylinder body 1h, and when the power chamber R1 is in a high pressure state, the first seal member 18a and the second Is securely sealed by the seal member 18b, but the pressure is accumulated in the intermediate chamber Rm therebetween. At this time, the pressure transmission from the power chamber R1 side to the communication path 17e through the communication path 1d is performed by the third seal member 18
c. When the power chamber R1 enters a low pressure state, the high-pressure fluid stored in the intermediate chamber Rm is discharged to the power chamber R1 via the communication passage 17e and the communication passage 1d. At this time, the third seal member 18c is connected to the power chamber R1.
It is configured to allow pressure transmission to the side,
The pressure in the intermediate chamber Rm is immediately reduced. The fourth seal member 18d is used for sealing the rear side of the gap between the sleeve 17 and the cylinder body 1h, but is not necessarily provided at this position, and may be provided separately from the sleeve 17. Is also good.

As described above, the third seal member 18c functions as a one-way sealing means, and can contribute to preventing pressure accumulation in the intermediate chamber Rm. In particular, the communication path 17e and the communication path 1d are pressure accumulation discharge paths, and are paths different from the high pressure fluid introduction path between the piston 12 and the first and second seal members 18a, 18b. Therefore, the pressure accumulation in the intermediate chamber Rm can be reliably prevented, and the effect can be appropriately maintained.

FIG. 2 shows a sealing device according to another embodiment of the present invention. In place of the radial communication passage 17e shown in FIG. 1, one end has a first sealing member 18 from the power chamber R1 side.
A communication path 17f is formed, which communicates with the intermediate chamber Rm between the first seal member a and the second seal member 18b and whose other end communicates with the power chamber R1. As a one-way sealing means, a check valve 18v is provided on the power chamber R1 side instead of the third seal member 18c. The check valve 18v has a ball valve body and a spring, prevents pressure transmission from the power chamber R1 side to the intermediate chamber Rm side, and allows pressure transmission from the intermediate chamber Rm side to the power chamber R1 side. The above third seal member 1
Functions similarly to 8c. Incidentally, the spring of the check valve 18v is not always necessary, and the check valve 18v may be provided on the intermediate chamber Rm side. Thus, also in the present embodiment, the check valve 18v can reliably prevent the accumulation of pressure in the intermediate chamber Rm.

FIG. 3 shows an embodiment of the hydraulic brake device according to the present invention, which is provided with the sealing device shown in FIG. 1, but may be provided with the sealing device shown in FIG. The cylinder body 1h of this embodiment includes a master cylinder section and a regulator section as pressure regulating valve means, and a brake pedal 2 as a brake operating member is provided on the rear side of the vehicle (right side in FIG. 3). The pedaling force applied to the brake pedal 2 is transmitted as a brake operating force via the push rod 3 and the input member 4, and the output brake fluid pressure of the master cylinder unit and the regulator unit is accordingly changed to the right and left front wheels of the vehicle. FR, FL, and wheel cylinders Wfr, W of rear right and left wheels RR, RL
The signals are output to fl, Wrr, and Wrl (FIG. 3 shows only the front and rear wheels FR, RR on the right side of the vehicle, and the wheel cylinders Wfr, Wrr mounted on each wheel).

The cylinder body 1h is formed with a stepped hole composed of holes 1a, 1b, 1c and the like having different inner diameters.
The master piston 10 and the control piston 21 are accommodated therein, and a pressure chamber R2 is defined between the master piston 10 and the control piston 21. The hole 1a communicates with a power chamber R1 having a larger inner diameter. A control piston 21 is slidably fitted in the hole 1b having the smallest diameter in a liquid-tight manner. The master piston 10 includes two pistons 11 and 12, and both ends of the piston 11 are accommodated and supported in both the hole 1b and the hole 1a having a larger diameter. That is, on the outer surface of the piston 11, a small-diameter land portion 11a is formed at the front end portion, and the large-diameter land portion 1a is located rearward at a predetermined distance in the axial direction.
1b, an annular cup-shaped sealing member 14 is disposed on the former, and is fitted slidably in a liquid-tight manner in the hole 1b, and the latter is slidably fitted in the hole 1a and is fitted on the piston 12. It is arranged to be in contact.

A cylindrical support portion 11s is formed on the land 11a side of the piston 11 so as to extend therefrom.
Are formed. In addition, a through hole 11c is formed in the radial direction of the piston 11, and an axial communication hole 11d communicating with the through hole 11c is formed, and is open to the concave portion 11e.
The retainer 16 is mounted on the support portion 11s, and the valve body 25 is locked to the retainer 16 to restrict the movement of the valve body 25 in the direction of the control piston 21. An elastic member such as rubber is attached to one end of the valve body 25, and is configured to abut on the communication hole 11d to seal it. A rod 25b is integrally formed on the other end of the valve body 25, and a locking portion 25
c is formed. The land 1 of the piston 11
A communication hole 11f is formed in the peripheral direction of the periphery of 1a. An annular seal member 14 is attached to an opening end on the pressure chamber R2 side in front of the communication hole 11f, and these constitute a check valve. Therefore, the liquid supply chamber R5 can communicate with the pressure chamber R2 via the communication holes 11c and 11d and the communication hole 11f. The liquid supply chamber R5 is connected to the hydraulic pressure passage 1.
e, and communicates with the reservoir 6.

Further, a piston 12 is accommodated behind the piston 11. The piston 12 has a land portion 12a formed on a front outer surface thereof. An annular seal member 12b is mounted on the land portion 12a and is fitted in the hole 1a in a liquid-tight slidable manner. The liquid supply chamber R5 is separated. Further, a concave portion 12c is formed behind the piston 12, and the input member 4 is housed in the concave portion 12c, and is screwed with the contact member 5 at the front. The front end face of the piston 12 faces the rear end face of the piston 11, and the pressing force from the brake pedal 2 is transmitted to the piston 11 via the input member 4 and the contact member 5. The main body of the piston 12 is supported by the sleeve 17 as described above. That is,
As shown in FIG. 4 in an enlarged manner, the piston 12 and the power chamber R1 include the configuration shown in FIG. Incidentally, the piston 11 and the piston 12 may be formed integrally.

Next, a regulator portion is formed in a front portion of the cylinder body 1h, and an auxiliary hydraulic pressure source 40 is connected to the regulator portion, and the output power hydraulic pressure is appropriately controlled and output. The auxiliary hydraulic pressure source 40 includes a hydraulic pump 43 driven by an electric motor 42, the input side of which is connected to the reservoir 6 and the output side of which is connected to the accumulator 44,
The power hydraulic pressure is supplied from the accumulator 44 to the communication hole 31d via the hydraulic pressure path 1p. The control piston 21 accommodated in the hole 1c is formed with a pair of lands 21a and 21b at a predetermined distance in the axial direction. An annular seal member 24 is mounted only on the front land 21a. , The rear land portion 21b communicates. Therefore, the pressure chamber R2 and a regulator chamber R3 described later are separated by the seal member 24, and the pressure chamber R2 is formed between the seal member 24 and the seal member 14 mounted on the land 11a of the piston 11. Have been.

As shown in FIG. 3, the control piston 21 is formed with a through hole 21c penetrating in the radial direction and extending in the axial direction and opening at the rear end. Land part 2 in front
1a is a locking pin 2 which is located at the rear end and extends radially.
8 is fixed to the cylinder body 1h, which allows the control piston 21 to move forward, but restricts retreat (movement in the direction of the master piston 10). The through-hole 21c of the control piston 21 also extends in the axial direction, and a cylindrical support portion 21s is integrally formed so as to surround the through-hole 21c, and the locking portion 25c of the valve body 25 is accommodated therein. Have been. A retainer 26 is attached to the support portion 21s, and a retaining portion 25c is retained by the retainer 26, thereby restricting the movement of the valve body 25 in the direction of the master piston 10. A concave portion is formed at an axial end of the control piston 21 in a direction opposite to the retainer 26, and a distal end portion of a spool 32 described later is held in the concave portion.

In the stepped hole 1c communicating with the hole 1b, cylindrical sleeves 31 and 36 are fitted, and a regulator chamber R3 as a pressure regulating chamber is formed between the sleeve 31 and the control piston 21. Have been. A plurality of annular grooves are formed on the outer periphery of the sleeves 31 and 32, and annular seal members are fitted to the respective annular grooves. Between these adjacent seal members, communication holes 31d and 31f are formed in the radial direction of the sleeve 31.
Are formed, and communication holes 36b, 3 are formed in the radial direction of the sleeve 36.
6c is formed. A spool 32 is slidably housed in the hollow portion of the sleeve 31.
Is arranged so that the opening of the communication hole 31f is shielded by the forward movement of.

In the axial direction of the sleeve 31, there is formed a communication hole 31e having one end communicating with the communication hole 31f and the other end communicating with the regulator chamber R3. When the communication hole 31f is open, the regulator chamber R3 Are communicating holes 31e, 3
It is configured to be able to communicate with the hydraulic path 1s via 1f. The communication hole 31d is connected to the auxiliary hydraulic pressure source 40 through the hydraulic pressure path 1p, but is shielded by the outer peripheral surface of the spool 32 at the position shown in FIG. Furthermore, the communication hole 3
An annular groove 31c is formed in the inner peripheral surface of the sleeve 31 behind 1d. The communication holes 36b and 36c are connected to the hydraulic passages 1q and 1r, respectively.

A plunger 35 is fitted to the front end of the spool 32 so as to protrude in the axial direction.
The rear end is located in the regulator chamber R3 and is locked to the control piston 21. That is, the retainer 33 is supported in the concave portion in front of the control piston 21,
A spring 34 is stretched between the control piston 21 and the spool 32 and the spool 32 is urged to abut the control piston 21. At the initial position (retracted position) of the control piston 21, the opening of the communication hole 31f is not shielded by the spool 32, and the regulator chamber R3 is connected to the communication holes 31e and 31f of the sleeve 31 and the hydraulic pressure path 1s. And is filled with brake fluid at atmospheric pressure.
In the outer peripheral surface of the spool 32, an annular groove 32b is formed at a retreat position over a predetermined range in the axial direction centered on the rear end of the sleeve 31, and a predetermined distance is provided in front of the annular groove 32b. An annular groove 32c is formed at a position facing the groove 31c.

At the position shown in FIG. 3, the inside of the regulator chamber R3 communicates with the reservoir 6 through the communication holes 31e and 31f of the sleeve 31 and the hydraulic pressure path 1s, and is at atmospheric pressure. When the spool 32 moves forward with the forward movement of the control piston 21, the communication hole 31f of the sleeve 31 is shut off, and instead the communication hole 31d faces the groove 32c of the spool 32, and the groove 31c and the groove 32b
Oppose each other and thus communicate with the auxiliary hydraulic pressure source 40. As a result, the power hydraulic pressure of the auxiliary hydraulic pressure source 40 becomes
It is supplied to the inside and is boosted.

On the other hand, the hollow portion of the sleeve 36 is formed in a stepped hole shape, and the transmission member 37 is accommodated in the small diameter hole portion so as to be slidable in the axial direction, and the rear end faces the tip of the plunger 35. Are located. Further, the sleeve 36
An elastic member 38 made of rubber, for example, is fitted into the large-diameter hole portion, and the distal end of the transmission member 37 is arranged so as to abut this. In the present embodiment, a contact member (not shown) having a truncated cone shape is provided at the tip of the transmission member 37, but the tip of the transmission member 37 may be formed in the same shape. A plug 39 is fitted to the distal end of the hollow portion of the sleeve 36, and a regulator chamber R4 is formed between the plug 39 and the elastic member 38.

The regulator chamber R4 is connected to the regulator chamber R3 via the communication hole 36b and the hydraulic path 1q, and is also connected to the power chamber R1 via the communication hole 36c and the hydraulic path 1r. The pressure chamber R2 is connected to the wheel cylinder Wfr via a hydraulic path 1n, and the power chamber R1 is connected to the wheel cylinder Wrr via a hydraulic path 1k.
Is connected to the

Next, the overall operation of the hydraulic brake device having the above configuration will be described. FIGS. 3 and 4 show a state in which the brake pedal 2 is not operated. The power chamber R1 has a hydraulic passage 1r, a regulator room R4, a hydraulic passage 1q, a regulator room R3, communication holes 31e, 31f, and a hydraulic passage. It communicates with the reservoir 6 via the pressure path 1s, and is in a low pressure state equal to the atmospheric pressure. In this state, when the brake pedal 2 is operated to push the pistons 11 and 12 forward (to the left in FIG. 3) via the push rod 3, the transmission member 4, and the abutting member 5, the piston 11 is moved to the valve body. 25 abuts, the communication hole 11d is closed by the elastic member of the valve body 25, and the pressure chamber R2
The communication between the liquid supply chamber R5 and the liquid supply chamber R5 is interrupted, and a closed state is established. As described above, when the pistons 11 and 12 are driven by the operating force of the brake pedal 2 in a state where the communication between the pressure chamber R2 and the liquid supply chamber R5 is interrupted, the piston 11
Since they are held in the state shown in FIG.

Accordingly, the communication hole 31f is closed by the spool 32 supported by the control piston 21, and the communication with the reservoir 6 is cut off. At the same time, the power hydraulic pressure from the auxiliary hydraulic pressure source 40 flows into the regulator chamber R3 from the hydraulic pressure path 1p through the communication hole 31d, the annular grooves 31c, 32c, and the groove 32b, and as the regulator hydraulic pressure, 1q
Is supplied to the regulator chamber R4 through the
The power is supplied to the power chamber R1 via r. by this,
The power chamber R1 is brought into a high pressure state, the pistons 11 and 12 are assisted to move forward, the inside of the pressure chamber R2 is further compressed, and the master cylinder hydraulic pressure is supplied from the hydraulic pressure passage 1n to the wheel cylinder Wfr.
And the regulator hydraulic pressure is output to the wheel cylinder Wrr via the hydraulic passage 1k.

During this time, the force applied to the control piston 21 by the regulator fluid pressure in the regulator chamber R3 is:
If the force applied to the control piston 21 by the master cylinder fluid pressure in the pressure chamber R2 is larger than the control piston 2
1 moves rearward, the communication hole 31f opens and communicates with the reservoir 6, so that the pressure in the regulator chamber R3 is reduced. When the relationship of the force applied to the control piston 21 is reversed, the control piston 21 moves forward, the communication hole 31f is shut off, and the regulator chamber R3 is replaced with the communication hole 31d.
Thus, the pressure in the regulator chamber R3 is increased. Such a control piston 21
By repeating the movement of the spool 32 accompanying the movement of
Control is performed so that the force by the regulator hydraulic pressure applied to the control piston 21 and the force by the master cylinder hydraulic pressure are equal. Until the force due to the regulator hydraulic pressure in the regulator chamber R4 is transmitted to the plunger 35 via the elastic member 38 and the transmission member 37, the regulator hydraulic pressure that is substantially proportional to the master cylinder hydraulic pressure is output, and the first hydraulic pressure is output. Brake fluid pressure characteristics are obtained.

Further, the regulator fluid pressure is increased, and the central portion of the elastic member 38 is displaced rearward by the regulator fluid pressure supplied to the regulator chamber R4, so that the transmission member 37 abuts on the plunger 35 and the spool 32 is moved rearward. When pressed, the opening area of the communication hole 31f increases. As a result, the regulator pressure in the regulator chamber R3 is reduced, and the second pressure having a pressure increasing gradient which is substantially proportional to the master cylinder pressure but is gentler than the pressure increasing gradient of the first brake fluid pressure characteristic.
Brake fluid pressure characteristics of

In the above-described operation, when the power chamber R1 is in a low pressure state, the regulator fluid pressure accumulated in the intermediate chamber Rm is discharged to the power chamber R1 via the communication passages 17e and 1d as shown in FIG. The fluid is further discharged to the reservoir 6 via the hydraulic pressure passage 1r, the regulator chamber R4, the hydraulic pressure passage 1q, the regulator chamber R3, the communication holes 31e and 31f, and the hydraulic pressure passage 1s. At this time, the third seal member 18c is configured to allow pressure transmission to the power chamber R1 side, and the intermediate chamber Rm is immediately depressurized.
m can be reliably prevented from accumulating.

[0036]

Since the present invention is configured as described above, the following effects can be obtained. That is, according to the reciprocating member sealing device of the present invention, the holding member is interposed between the reciprocating member and the main body, and the first and second sealing members that are in contact with the reciprocating member are held by the holding member. In addition, the holding member forms a communication passage through which the intermediate chamber between the first seal member and the second seal member communicates with the fluid chamber, and a pressure transmission from the fluid chamber side to the intermediate chamber side is formed in the communication passage. Is provided, and the one-way sealing means that allows pressure transmission in the opposite direction is provided, so that the communication path becomes a pressure accumulation discharge path, and the high-pressure fluid introduction path between the reciprocating member and the seal member is It will be a different route. Thus, the pressure accumulation in the intermediate chamber can be reliably prevented, and the effect of preventing the pressure accumulation can be appropriately maintained. Moreover, there is no need for complicated processing, and it can be easily manufactured.

Further, in the vehicle hydraulic brake device of the present invention, the above-mentioned sealing device is provided, and the accumulator discharge path is a communication path, and the high pressure fluid is introduced between the master piston and the first and second seal members. Since it will be different from the route,
The pressure accumulation in the intermediate chamber can be reliably prevented, and the effect of preventing the pressure accumulation can be appropriately maintained. Moreover, since this communication passage is formed in the sleeve, the sealing device can be formed with a simple structure,
The hydraulic brake device can be easily manufactured, and thus the hydraulic brake device can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a reciprocating member sealing device of the present invention.

FIG. 2 is a sectional view of another embodiment of the reciprocating member sealing device of the present invention.

FIG. 3 is a cross-sectional view of one embodiment of the vehicle hydraulic brake device of the present invention.

FIG. 4 is an enlarged sectional view showing a rear portion of the embodiment of the vehicle hydraulic brake device of the present invention.

FIG. 5 is a sectional view of a conventional sealing device for a reciprocating member.

FIG. 6 is a cross-sectional view showing a sealing device portion in a conventional hydraulic brake device for a vehicle.

[Explanation of symbols]

 1h Cylinder body 1e, 1p, 1q, 1r, 1s, 1k, 1n Hydraulic pressure passage 1d Communication passage 2 Brake pedal 6 Reservoir 10 Master piston 11 Piston 12 Piston 17 Sleeve 17a, 17b, 17c, 17d Annular groove 17e Communication passage 18a 1st seal member 18b 2nd seal member 18c 3rd seal member 18d 4th seal member 18v Check valve 21 Control piston 32 Spool 40 Auxiliary hydraulic pressure source R1 Power room R2 Pressure chamber R3, R4 Regulator room R5 Liquid supply Room Rm Intermediate room

Claims (6)

[Claims] 1. A main body defining a fluid chamber, a reciprocating member supported reciprocally with respect to the main body and supported so as to be partially exposed to the fluid chamber, and a reciprocation of the reciprocating member. For a device provided with pressure adjusting means for selectively adjusting the fluid chamber to at least a low pressure state and a high pressure state in accordance with movement, a support portion of the reciprocating member to the main body, A sealing member for a reciprocating member comprising a first sealing member and a second sealing member arranged side by side at a predetermined distance along the holding member, wherein the holding member is interposed between the reciprocating member and the main body. Holding the first seal member and the second seal member, and communicating an intermediate chamber between the first seal member and the second seal member in contact with the reciprocating member with the fluid chamber. A holding member that forms a communication passage, and a holding member that is disposed in the communication passage. A one-way sealing means for preventing pressure transmission from the fluid chamber side to the intermediate chamber side and allowing pressure transmission from the intermediate chamber side to the fluid chamber side. Sealing device. 2. The one-way sealing means prevents the communication passage from transmitting pressure from the fluid chamber side to the intermediate chamber side and allows pressure transmission from the intermediate chamber side to the fluid chamber side. The sealing device for a reciprocating member according to claim 1, wherein the sealing member is arranged as described above. 3. The reciprocating member sealing device according to claim 1, wherein the one-way sealing means is a check valve interposed in the communication passage. 4. A master piston is reciprocally supported in a cylinder body, a pressure chamber is formed in front of the master piston, and a power chamber is formed in the rear, and brake fluid is stored when the brake operating member is not operated. A master cylinder that communicates the pressure chamber and the power chamber to a reservoir to be driven, drives the master piston forward in response to operation of the brake operating member, and outputs brake fluid pressure from the pressure chamber, and a brake in the reservoir. An auxiliary hydraulic pressure source that boosts the liquid to a predetermined pressure and outputs a power hydraulic pressure, and a control piston that is reciprocally supported in front of the master piston in the cylinder body and disposed so as to interlock with the master piston. Pressure regulating valve means for introducing output power hydraulic pressure of the auxiliary hydraulic pressure source into a pressure regulating chamber and regulating the output power hydraulic pressure to a predetermined pressure in accordance with movement of the control piston. A hydraulic brake device for a vehicle that applies the brake fluid pressure regulated by the pressure regulating valve means to the power chamber to assist the master piston, and is interposed between the master piston and the cylinder body. A sleeve for holding a first seal member and a second seal member side by side at a predetermined distance along an axis of reciprocation of the master piston, and the first seal in contact with the master piston; A sleeve forming a communication passage communicating the intermediate chamber between the member and the second sealing member with the power chamber; and a pressure transmission from the power chamber side to the intermediate chamber side provided in the communication passage. And a one-way sealing means for allowing pressure transmission from the intermediate chamber side to the power chamber side. 5. The one-way sealing means prevents the communication passage from transmitting pressure from the power chamber side to the intermediate chamber side and allows pressure transmission from the intermediate chamber side to the fluid chamber side. The hydraulic brake device for a vehicle according to claim 4, wherein the seal member is disposed as described above. 6. The hydraulic brake system for a vehicle according to claim 5, wherein said one-way sealing means is a check valve interposed in said communication passage.