JP2002037052A - Hydraulic braking device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily set the initial position of an input member to a power piston in a hydraulic braking device provided with an auxiliary hydraulic pressure source, a pressure regulating means and a power piston. SOLUTION: In this device, the power piston 21 is disposed behind a master piston 12, and output power hydraulic pressure of an auxiliary hydraulic pressure source 40 is supplied to a power chamber R6 formed behind the power piston, through the pressure regulating means. The other end of a support member (a case 29) with a locking part 29b formed at one end is fixed to a housing 2 slidably storing the power piston. One end of a guide member 28 is slidably supported to the support member (the case 29), while the other end is fixed to an input member, and the locked position of one end of the guide member to a locking part of the support member is set as the initial position of the input member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake device for supplying brake hydraulic pressure to a wheel cylinder of a vehicle wheel, and more particularly, to a hydraulic brake device having an auxiliary hydraulic pressure source, a pressure adjusting means, and a power piston in addition to a master cylinder. The present invention relates to a hydraulic brake device for a vehicle.

[0002]

2. Description of the Related Art Various types of hydraulic brake devices for automobiles are known.
No. 28062 discloses a hydraulic booster provided with an auxiliary hydraulic pressure source and a pressure adjusting means in addition to a master cylinder. In this publication, a power chamber is formed at one end of a power piston in a housing, a valve mechanism is provided in conjunction with an input shaft, and a discharge passage communicating the power chamber to a reservoir via the valve mechanism is provided. A first supply passage communicating the power chamber with the pressure fluid source via the first supply passage, and a second supply passage communicating the power chamber with the pressure fluid source without the intervention of the valve mechanism; and a second supply passage for opening and closing the second supply passage. A first on-off valve and a second on-off valve for opening and closing the discharge passage are provided. If the first on-off valve is opened and the second on-off valve is closed, the second
Pressurized fluid can be introduced into the power chamber via the supply passage, which is not discharged to the reservoir, so that the power piston can be advanced without stepping on a brake pedal or the like, thus, for example, automatic braking operation Is described.

[0003] Further, in Japanese Patent Application Laid-Open No. 63-199166, the content of the description is not necessarily clear, but in consideration of the drawings, an operating piston (1) corresponding to a power piston is considered.
8), an auxiliary hole (30) is formed, and a damper chamber (33) is formed between the auxiliary piston (31) and the auxiliary hole (30) accommodated therein, and the damper chamber (33) communicates with the reservoir. The passage (35) is configured to restrict the fluid (brake fluid) passing therethrough. Thus, when the brake pedal is operated after the operation piston (18) is operated independently of the brake pedal, the speed at which the fluid in the damper chamber (33) flows out through the passage (35) is limited. . Thus, when citing the expression in the publication,
It is stated that the driver does not experience long pedal movements but feels momentary pedal reaction and braking effects.

[0004]

SUMMARY OF THE INVENTION The above-mentioned JP-A-3-28.
In the hydraulic booster described in Japanese Patent Application Laid-Open No. 062, there is no description about the adjustment of the relative positional relationship between the input shaft and the power piston, and furthermore, the valve mechanism. Is made at the mounting of the brake pedal. Although a boot is provided on the input shaft in the drawing, it is used to prevent intrusion of dust and the like, and is not used for positioning the input shaft.

On the other hand, in Japanese Patent Application Laid-Open No. 63-199166, it is shown that the auxiliary piston (31) is connected to the pedal (11) via a push rod (32).
The positioning is not described. Therefore, it is presumed that this is also performed at the mounting portion of the brake pedal.

In any of the devices described in the publications, setting the initial position of the input member with respect to the power piston is important, but if the adjustment is performed at the mounting portion of the brake pedal, the setting of the initial position is easy. Rather, a large number of assembly steps are required when mounting the brake device on the vehicle body.

Therefore, the present invention can easily set an initial position of an input member with respect to a power piston in a vehicle hydraulic brake device provided with an auxiliary hydraulic pressure source, a pressure adjusting means, and a power piston in addition to a master cylinder. It is an object to provide a hydraulic brake device.

[0008]

In order to solve the above-mentioned problems, the present invention provides a method for driving a master piston forward in response to an operation of a brake operation member to increase the pressure of brake fluid in a reservoir. A master cylinder that outputs brake fluid pressure, a power piston that is arranged behind the master piston, and forms a power chamber behind, and boosts brake fluid in the reservoir to a predetermined pressure to output power fluid pressure. An auxiliary hydraulic pressure source, and pressure adjusting means connected to the auxiliary hydraulic pressure source and connected to the reservoir, for adjusting the output power hydraulic pressure of the auxiliary hydraulic pressure source to a predetermined pressure and supplying the output power hydraulic pressure to the power chamber. In a hydraulic brake device for a vehicle, an input member that is supported so as to be axially movable relative to the power piston and moves in response to operation of the brake operation member,
A support member having a locking portion formed at one end thereof, the other end being fixed to a housing for slidably housing the power piston, one end slidably supported by the support member, and the other end being the input And a guide member fixed to a member, wherein a position where one end of the guide member is locked by the locking portion of the support member is set to an initial position of the input member. The pressure adjusting means may be any of means called a regulator, a hydraulic booster, a hydraulic servo and the like. As the housing that houses the power piston, a housing that houses the entirety together with the master cylinder and the like, a booster housing that is joined to the master cylinder housing that houses the master cylinder to form a hydraulic booster, and the power piston A unit housing which is housed together with the pressure adjusting means and the like to form a pressure adjusting unit body is included.

In the above-mentioned hydraulic brake device, the support member comprises a cylindrical body for accommodating the input member and the guide member, and a locking portion formed at one end of the cylindrical body. The other end of the cylindrical body may be fixed to a housing that houses the power piston at a position where one end of the guide member is locked, and an initial position of the input member may be set.

According to a third aspect of the present invention, the pressure adjusting means is formed in the power piston, and a damper chamber is formed in the power piston between the pressure adjusting means and the input member. The damper chamber may be configured to communicate with the atmosphere via a throttle formed in the input member.

[0011] Further, a normally-closed electromagnetic on-off valve interposed in a hydraulic passage connecting the power chamber to the auxiliary hydraulic pressure source, and an interlocking valve in a hydraulic passage connecting the pressure regulating means to the reservoir. And a normally-open electromagnetic on-off valve that drives the auxiliary hydraulic pressure source and switches the normally-closed electromagnetic on-off valve and the normally-opened electromagnetic on-off valve to an open position and a closed position, respectively. Thereby, it can be configured to perform automatic braking.

[0012]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 and 2 show a hydraulic brake device according to an embodiment of the present invention, in which a pedaling force applied to a brake pedal 3 is transmitted as a brake operating force via an input rod 3a. The brake fluid pressure is output from the master cylinder 10 by being assisted by the assist device 20, and is supplied to a wheel cylinder (not shown) mounted on each wheel of the vehicle. As the hydraulic pressure assisting device 20, various names such as a hydraulic pressure booster and a regulator are used, but any of them may be used. FIG. 1 shows the overall configuration, and FIG. 2 shows an enlarged view of the hydraulic assisting device 20.

The master cylinder 10 of the present embodiment is shown in FIG.
As shown in FIG. 1, master pistons 11 and 12 are housed in series in a master cylinder housing 1 of a cylinder body composed of a first cylinder 1a and a second cylinder 1b and a third cylinder 1c housed therein. Tandem master cylinder. The first cylinder 1a is a cylindrical body with a bottom, and is formed with a stepped hole so that the inner diameter increases sequentially from the cylinder bore 1d toward the opening. The first cylinder 1a has a liquid supply port 1i, 1j and an output port 1
m, 1n are formed.

The second cylinder 1b is a substantially cylindrical body and has a cylinder bore 1e having the same diameter as the cylinder bore 1d. At the front end of the second cylinder 1b, the first cylinder 1
A flow path 1h communicating with the liquid supply port 1i is formed inside a, and a cup-shaped seal member S1 is disposed in front of the flow path 1h so as to expand forward. Further, a cup-shaped seal member S2 is also arranged on the rear inner side of the flow path 1h so as to expand rearward. The third cylinder 1c is a cylinder superimposed on the rear part of the second cylinder 1b, and has an annular flow path 1f formed therebetween, and is formed between the first cylinder 1a and the second cylinder 1b. It is configured to communicate with an annular flow path 1g. An output port 1n is open in this flow path 1g. A channel 1k communicating with the liquid supply port 1j is formed on a side surface of the third cylinder 1c.
An annular member 17 is disposed in the opening of the first embodiment.

A cup-shaped seal member S3 expanding forward and a cup-shaped seal member S4 expanding rearward are disposed on both sides of the annular member 17, and an opening of the flow path 1f is provided in front of the seal member S3. Is located above the flow path 1 above the seal member S4.
It is arranged so that the opening of k may be located. And
A bottomed cylindrical master piston 11 is provided in the cylinder bore 1d.
Are slidably housed in a liquid-tight manner, and the first cylinder 1
A first pressure chamber R <b> 1 is defined between a and the master piston 11. The master piston 12 is housed in the cylinder bore 1e, and the annular member 17 and the seal member S
3 and S4 slidably supported in a liquid-tight manner, and a second pressure chamber R is provided between the master piston 11 and the master piston 12.
2 is sectioned.

At the rear end position of the master piston 11 at the time of non-operation, a communication hole 11a formed in a skirt portion thereof is opposed to the flow path 1h, and the first pressure chamber R is provided via a liquid supply port 1i.
1 is configured to communicate with the reservoir 4. Further, at the rear end position of the master piston 12 at the time of non-operation, the communication hole 12a formed in the skirt portion thereof has a seal member S.
3 through the flow path 1k and the liquid supply port 1j.
Are configured to communicate with the reservoir 4. Thus, the seal member S3 is positioned at the position shown in FIG.
It is configured to allow the flow of the brake fluid from the side to the pressure chamber R2 side and prevent the flow in the reverse direction. Further, the sealing member S4 is connected to a sealed chamber R3 (described later) from the flow channel 1k side.
It is configured to allow the flow of the brake fluid to the side and prevent the flow in the reverse direction.

A spring 13 is stretched between the front end surface in the first cylinder 1a and the bottom surface of the concave portion of the master piston 11, and the master piston 11 is urged rearward. A rod 14a is provided on the bottom surface of the concave portion of the master piston 11.
Is fixed at one end, and the other head is a retainer 14b.
The rear end position of the master piston 11 is regulated by these components. Similarly, a spring 15 is stretched between the rear end surface of the master piston 11 and the bottom surface of the concave portion of the master piston 12, and is urged in a direction separating them. One end of a rod 16a is fixed to the bottom surface of the concave portion of the master piston 12, and the head at the other end is disposed so as to be able to be engaged with the tip of the retainer 16b. The end position is regulated.

A closed chamber R3 is provided behind the master piston 12.
The hydraulic pressure assisting device 20 is configured via the. A first cylinder 1a constituting the master cylinder housing 1 is joined with a fourth cylinder 2a of a bottomed cylindrical body constituting the booster housing 2, and its cylinder bore 2b
Has a larger diameter than the cylinder bores 1d and 1e of the master cylinder, in which a power piston 21 is housed so as to be slidable in a liquid-tight manner. As shown in FIG. 2, lands 21x and 21y are formed on the front and rear of the power piston 21, and seal members S5 and S7 are respectively fitted thereto. Further, a seal member S6 is provided on the inner surface of the cylinder bore 2b therebetween, and a seal member S8 is provided around the bottom opening 2c of the fourth cylinder 2a. Note that the seal member S is actually
In order to arrange 5 to S7 as shown in FIG. 2, it is necessary to take measures such as dividing the power piston 21 into two parts. However, since this is a design matter, it will be described as one part.

Thus, the sealing members S4 and S5
Between the sealing member S5 and the sealing member S6, an annular drain chamber R4 between the sealing members S5 and S6, an annular liquid supply chamber R5 between the sealing members S6 and S7, and between the sealing members S7 and S8. Each of the annular power chambers R6 is formed. The pressure adjusting means of the present invention is configured in the power piston 21 as follows. As shown in an enlarged manner in FIG.
a, a large-diameter cylinder bore 21b, a maximum-diameter cylinder bore 21j, a small-diameter cylinder bore 21c, and a large-diameter cylinder bore 21d are formed. A communication hole 21h that communicates the cylinder bore 21b with the drain chamber R4, a cylinder bore 2
A communication hole 21g that communicates 1c with the liquid supply chamber R5, and a communication hole 21e that communicates the cylinder bore 21c with the power chamber R6.
21f is formed. In this case, for example, in order to form the cylinder bore 21j in the power piston 21,
Although it is necessary to take measures such as dividing the power piston 21 into two parts, it is a matter of design, so that it will be described as one part.

The plunger 22 constituting the input member of the present invention is slidably accommodated in the cylinder bore 21d. The plunger 22 is a cylindrical body, and has an annular groove 22a formed in an intermediate outer peripheral surface thereof and a radial throttle hole 22b communicating the annular groove 22a with the hollow portion 22c. Further, an annular groove (symbol is omitted) is also formed in front of the annular groove 22a of the plunger 22, and a seal member S9 is fitted in this annular groove. Therefore, the gap between the outer peripheral surface of the plunger 22 and the inner surface of the cylinder bore 21d is fluidly separated through the seal member S9, but the space before and after the seal member S9 is formed by the annular groove 22a, the throttle hole 22b, It communicates via the hollow part 22c.

A plug member 27 is fitted to the rear end of the hollow portion 22c of the plunger 22, and an input rod 3a is connected to a bearing formed behind the plug member 27.
Further, an annular guide member 28 is sandwiched between the rear end of the plunger 22 and the plug member 27, and a sliding member 28s is mounted on the outer periphery thereof. These plug members 2
The guide member of the present invention is constituted by the guide member 7 and the guide member 28.

On the other hand, at the rear end of the booster housing 2, a front end 29a of a tubular case 29 is fixed by caulking. The case 29 supports the guide member 28 slidably along the inner peripheral surface, and constitutes a support member of the present invention. The rear end portion 29b of the case 29 is bent inward to form a locking portion for the guide member 28,
The position where the guide member 28 is locked to the locking portion is the initial position of the plunger 22, and the rear end portion 29b prevents the plunger 22 from falling off. Note that the sliding member 28s has no sealing property, and therefore the inside of the case 29 is under atmospheric pressure.

The cylinder bore 21 in front of the plunger 22
A first spool 23 is slidably housed in c, and a second spool 24 is slidably housed in a cylinder bore 21b in front of the first spool 23. And recess 2
A reaction force rubber disk 25 is disposed at 1a as a reaction force transmission elastic member, and a metal plate 26 is housed in front of the reaction force rubber disk 25 in close contact with the reaction force rubber disk 25 so as to be able to move back and forth. These are arranged so that a slight gap is formed between the reaction force rubber disk 25 and the distal end surface of the second spool 24 when not operating as shown in FIGS. A damper chamber R7 is formed between the front end of the plunger 22 in the cylinder bore 21d and the rear end of the first spool 23. The damper chamber R7 has an annular groove 22a, a throttle hole 22b and a hollow part. It communicates with the space in the case 29 via 22c and is maintained at atmospheric pressure.

As shown in FIG. 2 in an enlarged manner, annular grooves 23a and 23b are formed on the outer peripheral surface of the first spool 23, and an axial hole 23d opening forward is formed.
It communicates with the annular groove 23a through the radial communication hole 23c. The front end of the first spool 23 is enlarged in diameter to form an enlarged diameter portion 23e, and the enlarged diameter portion 23e is disposed so as to be movably supported in the cylinder bore 21j. Then, the enlarged diameter portion 2 in the cylinder bore 21j
A spring 23f is provided in front of 3e, and the first spool 23 is urged rearward by the spring 23f. Therefore, when not in operation, as shown in FIG. 2, the rear end of the enlarged diameter portion 23e is pressed against the step portion 21k of the power piston 21. In this state, the annular grooves 23a and 23b of the first spool 23 are
e, 21f, and the power chamber R6 is connected to the hole 2 through the communication hole 21e, the annular groove 23a, and the communication hole 23c.
It communicates with 3d. When the first spool 23 moves forward, the communication between the power chamber R6 and the hole 23d is cut off, the annular groove 23b faces the opening of the communication hole 21f and the opening of the communication hole 21g, and the power chamber R6 communicates with the communication hole 21g. .

On the other hand, the second spool 24 has an annular groove 24a formed in the outer peripheral surface at the rear thereof, and has an axial hole 24c which opens rearward and faces the opening of the hole 23d of the first spool 23. Are formed, and communicate with the annular groove 24a via the radial communication hole 24b, and further communicate with the drain chamber R4 via the communication hole 21h. In addition, the first spool 2
In the state shown in FIG. 2, the third spool 24 and the second spool 24 come into contact with each other and move as a unit. However, as described later, a space may be formed between the spools 2 and 3 separately.

The booster housing 2 is formed with a drain port 2d and input ports 2e and 2f which are always in communication with the drain chamber R4. The drain port 2d is connected to a normally open on-off valve 6 as shown in FIG. It is connected to the reservoir 4. The on-off valve 6 is formed of a proportioning valve for performing fine control. On the other hand, the input ports 2e and 2f are connected to the auxiliary hydraulic pressure source 40 shown in FIG. The auxiliary hydraulic pressure source 40 includes a hydraulic pump 42 driven by an electric motor 41, the input side of which is connected to the reservoir 4, and the output side of which is a check valve 43.
Are connected to the accumulator 44 via the input port 2e and to the input port 2f via the normally closed on-off valve 5. If the opening / closing valve 5 is also constituted by a proportioning valve, finer control is possible. In the present embodiment, the auxiliary hydraulic pressure source 4
The pressure sensor P is connected to the accumulator 44 so that 0 is maintained at a predetermined output hydraulic pressure.

Further, in this embodiment, a flow passage 2g is formed in the booster housing 2 for communicating the closed chamber R3 and the power chamber R6, and the normally open differential pressure responsive check valve 30 is formed in the flow passage 2g. (Hereinafter, simply referred to as a check valve 30). That is, the communication state is always maintained, and the power chamber R6 is closed according to the pressure difference between the power chamber R6 and the sealed chamber R3. When the power chamber R6 is larger than the pressure in the sealed chamber R3 and the pressure difference is equal to or more than a predetermined value, The check valve 30 is closed, and the connection between them is shut off. On the other hand, when the hydraulic brake device is not operating, there is no pressure between the two and the check valve 30 is in the open position. Therefore, when filling the brake fluid, by evacuating from the power chamber R6 side, It is possible to easily and surely bleed the air in the closed chamber R3.

In the hydraulic brake device configured as described above, the power piston 21 is adjusted to a predetermined positional relationship with respect to the booster housing 2 and the plunger 2 is adjusted.
2. It is necessary to adjust the first spool 23 and the second spool 24 to a predetermined positional relationship with respect to the power piston 21, and it is necessary to adopt a structure capable of maintaining these positional relationships. In the present embodiment, the case 29 is structured so that the case 29 can be appropriately assembled to the booster housing 2 while maintaining these positional relationships. The booster housing 2, the power piston 21, the plunger 22, the first spool 23,
The assembly of the second spool 24, the case 29 and the like will be described with reference to FIG.

First, the plunger 22, the first spool 2
3. The power piston 21 in which the spring 23f and the second spool 24 are accommodated in the hollow portion is accommodated in the cylinder bores 2b and 2c of the booster housing 2. In this case, the first spool 23 is designed as described above.
It is necessary to take measures such as a two-part structure. However, here, the description will be made assuming that each part is housed in the booster housing 2 as shown in FIGS. That is, before the guide member 28 and the case 29 are mounted, the power piston 21, the plunger 22, the first spool 23, the spring 23f, and the second spool 24 are held in the positional relationship shown in FIGS. . Specifically, the master piston 12 is urged rearward by the spring 15 shown in FIG. 1, and the power piston 21 is urged rearward via the metal plate 26 and the reaction force rubber disk 25 that come into contact with the master piston 12. The stepped portion 21 is held at the rear end position where it is engaged with the booster housing 2. At this time, the first spool 23 causes the enlarged diameter portion 2
3e is pressed against the shoulder 21k and is located at the rear end position, and the plunger 22 is disposed so as to abut this. In this state (that is, before mounting the case 29), when the rear side is arranged so as to be upward, the state shown in FIG. 3 is obtained.

From the above state, the plug member 27 is fitted into the hollow portion 22c of the plunger 22 via the guide member 28, and the guide member 28 is sandwiched between the plunger 22 and the plug member 27. Then, the case 29 is mounted such that the sliding member 28s mounted on the outer periphery of the guide member 28 is in sliding contact with the inner surface of the case 29, and is urged toward the booster housing 2 by the presser PO and the spring BS. The urging force of the spring BS is set smaller than the urging force of the spring 23f in the power piston 21. Therefore, even in the state of FIG.
Is maintained in a state of being pressed against the shoulder 21k. In this state, the front end 29a of the case 29 is swaged to the rear end of the booster housing 2 by the jig CL. Thus, the initial positions of the plunger 22, and thus the first spool 23 and the second spool 24, with respect to the booster housing 2 are accurately set.

FIG. 4 shows a state of assembling a hydraulic brake device according to another embodiment. In this embodiment, the above-mentioned hydraulic assisting device 20 is replaced with a pressure adjusting unit 200.
1 and 2 are separate from the booster housing 2 to constitute a cartridge type sub-assembly. The unit housing of the pressure adjustment unit body 200 is
1. The three members 201 to 203 are formed by superimposing the three members, and the booster housing 2 shown in FIGS.
Of the power piston accommodating portion. Similarly, the power piston of this embodiment is also composed of three members 211 to 213, but is substantially the same as the power piston 21 of FIG. 1 and FIG. The first and second spools 230 and 240 are also the first and second spools 230 and 240 shown in FIGS.
The first spool 230 has its enlarged diameter portion 231 pressed against the front end face of the power piston member 212 by the urging force of the spring 23f. Since these configurations are substantially the same as those of the embodiment of FIGS. 1 and 2, detailed description will be omitted. The plug member 27, the guide member 28, the case 29, and the like are the same as those in FIGS. 1 and 2 except that the case 29 is caulked to the housing member 201 of the pressure regulating unit 200.

When assembling the case 29 to the pressure adjusting unit 200, the power piston member 213 is attached to the assembling table SU.
And the stopper ST supports the front end face of the
While the spool 240 is supported, the components are assembled according to the above-described assembly procedure. And the sliding member 28
The case 29 is mounted on the housing member 201 such that s slides on the inner surface of the case 29, and is urged in the direction of the pressure adjusting unit 200 by the presser PO and the spring BS. At this time, the enlarged diameter portion 231 of the first spool 230 is maintained in a state of being pressed against the front end surface of the power piston member 212. In this state, the front end 29
is caulked to the housing member 201 by the jig CL. Thus, with respect to the sub-assembly of the pressure adjusting unit 200, the initial positions of the plunger 22, and thus the first spool 230 and the second spool 240, are accurately set.

Next, the operation of the hydraulic brake device configured as shown in FIGS. 1 and 2 will be described. First, when the brake pedal 3 is in a non-operation state, each component is in a state shown in FIGS. 1 and 2, and the on-off valve 5 is in a closed position and the on-off valve 6 is in an open position. The rear end face of the master piston 12 is a metal plate 2
6, the hydraulic pressure assisting device 20 is in a non-operating state.
At this time, the closed chamber R3 has the communication hole 1k and the liquid supply port 1j.
And is under atmospheric pressure. On the other hand, the liquid supply chamber R5 is connected to the accumulator 44 of the auxiliary hydraulic pressure source 40, but the communication hole 21g is closed by the first spool 23. In the power chamber R6, the on-off valve 5 is in the closed position, the communication hole 21e, the groove 23a of the first spool 23 opposed to the communication hole 21e, and the communication hole 23c.
23d, the hole 24c of the second spool 24, the communication hole 24b and the groove 24a, the communication hole 21 of the power piston 21.
h, and communicates with the reservoir 4 via the port 2d. Further, the power chamber R6 communicates with the closed chamber R3 via the flow path 2g and the check valve 30. Thus, the auxiliary hydraulic pressure source 4
Even if 0 is driven, the power piston 21 is merely provided with a rearward pressing force by the liquid pressure in the liquid supply chamber R5, so that the power piston 21 is maintained at the stop position shown in FIGS.

When the brake operation is performed, the plunger 22
Is driven forward and the first spool 23 moves forward, the communication hole 21e is blocked by the first spool 23, and the communication between the power chamber R6 and the hole 23d is blocked.
Since the annular groove 23b faces the openings of the communication hole 21f and the communication hole 21g, the power chamber R is provided via the input port 2e, the communication hole 21g, the annular groove 23b and the communication holes 21f and 21e.
At 6 a power hydraulic pressure is introduced. At this time, since the power hydraulic pressure from the auxiliary hydraulic pressure source 40 has been introduced into the liquid supply chamber R5, the land portion 21y (rearward) applied in the direction of pressing the power piston 21 rearward by the power hydraulic pressure. Of the power piston 21 by the hydraulic pressure introduced into the power chamber R6 in response to the brake operation, and the brake operation force. Activated, the power room R6 at this time
Check valve 30 when the pressure difference between
Is closed and the flow path 2g is shut off by the check valve 30, so that the closed chamber R3 becomes a closed space filled with brake fluid. In other words, the area of the land portion 21y constituting the rear pressure receiving surface is determined by the pressure required to drive the power piston 21 forward at the start of the brake operation, to a pressure sufficient to close the check valve 30. The area is set as described above, whereby the check valve 30 can be reliably closed before the master cylinder hydraulic pressure is generated.

In this manner, during the assisting operation after the closed chamber R3 is made a closed space, the annular area of the land portion 21y is smaller than the brake operating force and the pressing force applied to the rear end face of the power piston 21. And the pressing force applied to the front end face of the power piston 21 by the pressure of the closed chamber R3 is controlled so as to be balanced. And the sealed room R3
Since the effective area of the land 21x of the power piston 21 is larger than the effective area of the master piston 12,
Master piston 1 with forward movement of power piston 21
2 moves forward and the master piston 12 and the power piston 21
5 becomes the same as that shown in FIG. 5 described later. In this state, the master piston 12 and the power piston 21 are fluidly connected and move integrally. As described above, at the time of assisting by the hydraulic assisting device 20, the power piston 21 and the master piston 12 are fluidly coupled via the brake fluid filled in the closed chamber R3, and the gap between the power piston 21 and the master piston 12 is increased. Since the power piston 21 and the master piston 12 advance integrally with the master piston 12 advanced (the same gap as in FIG. 5), the stroke of the brake pedal 3 is shortened.
During this time, the brake fluid pressure in the closed chamber R3 is transmitted to the brake pedal 3 via the metal plate 26 and the reaction force rubber disc 25, and a reaction force is applied.

FIG. 5 shows the operating state during automatic braking (active braking), in which the brake pedal 3 is not operated, the on-off valve 5 shown in FIG. 1 is in the open position, and the on-off valve 6 is in the closed position. And the auxiliary hydraulic pressure source 40 is driven.
In the initial position, the first and second spools 23 and 24 are in the same positional relationship as in FIG. 2, so that the communication hole 21g is blocked by the first spool 23 and the auxiliary hydraulic pressure source 40 is provided in the liquid supply chamber R5. Output power hydraulic pressure is applied. On the other hand, the power chamber R6 has a communication hole 21e, a groove 23a of the first spool 23 opposed thereto, a communication hole 23c and a hole 23d, a hole 24c of the second spool 24, a communication hole 24b and a groove 24a, and a power piston 21. Although it communicates with the communication hole 21h and the port 2d, since the on-off valve 6 is in the closed position,
The space between them becomes the brake fluid pressure in the power chamber R6, that is, the power fluid pressure. As a result, an equal pressure is applied to both ends of the first spool 23, and this state is maintained. On the other hand, the second spool 24 moves forward by the action of the power hydraulic pressure to The disc 25 is pressed, and a gap is formed between the first and second spools 23 and 24 as shown in FIG.

Also in this case, the check valve 30 is closed by the pressure difference between the power chamber R6 and the closed chamber R3, and the flow passage 2g is shut off by the check valve 30, so that the closed chamber R3 is filled with the brake fluid. It becomes a closed space. Therefore, the power piston 21 is driven forward by the brake fluid pressure introduced into the power chamber R6, and the master pistons 11 and 12 are pressed by the pressing force of the effective area integral of the power piston 21.
Is driven forward. Thus, when the brake pedal 3 is not operated, a desired brake hydraulic pressure can be output by appropriately controlling the auxiliary hydraulic pressure source 40 and the on-off valves 5, 6. At this time, since the brake pedal 3 is not operated, the plunger 22 remains at the initial position shown in FIGS. 1 and 2, and the capacity of the damper chamber R7 is maximized as shown in FIG.

When the driver operates the brake pedal 3 and performs a so-called additional step during the automatic braking operation as described above, the plunger 22 moves forward, but the air in the damper chamber R7 is restricted. It is discharged to the atmosphere through the hole 22b. For this reason, the damper room R7 is gradually reduced without being reduced all at once, and a damper effect is achieved. Thus, it is possible to suppress an abrupt increase in the stroke of the brake pedal 3 at the time of additional depression during the operation of the automatic brake, and to give an appropriate operational feeling to the driver.

If the hydraulic pressure assisting device 20 fails, no power hydraulic pressure is supplied to the liquid supply chamber R5 and the power chamber R6, and the drain chamber R4 is connected to the reservoir 4 via the port 2d.
And the inside of the sealed chamber R3 has a flow path 1k and a port 1j.
Communicates with the reservoir 4 via the, so that all of them remain at the atmospheric pressure. Therefore, when the input rod 3a is driven forward in response to the operation of the brake pedal 3, the second spool 24 comes into contact with the reaction rubber disc 25 via the plunger 22 and the first spool 23, and this reaction rubber The master piston 12 is pressed via the disk 25 and the metal plate 26,
The brake fluid pressure output in this case is integrated with the land portion 21 of the power piston 21.
Since it is determined not by the effective area of x but by the effective area of the master piston 12, the pressure increase gradient at the time of the failure of the hydraulic pressure assist device 20 is larger than the characteristic when the effective areas of both pistons are the same. Become.

[0040]

The present invention has the following effects because it is configured as described above. That is, according to the first aspect of the present invention, an input member which is supported to be movable in the axial direction relative to the power piston and moves in accordance with the operation of the brake operating member, and a locking portion is formed at one end. A support member that fixes the other end to a housing that slidably houses the power piston, and a guide member that slidably supports one end of the support member and fixes the other end to the input member, Since the position where one end of the guide member is locked to the locking portion of the support member is set to the initial position of the input member, the initial position at the time of automatic braking can be easily set. . The housing that houses the power piston slidably is a unit housing that houses the power piston together with the pressure adjusting means to form a pressure adjusting unit body, and that the support member is fixed to the unit housing. The sub-assembly of the formula can be used, and in this case, the initial position of the input member can be easily set.

According to a second aspect of the present invention, the support member is constituted by a cylinder housing the input member and the guide member, and one end of the guide member is engaged with a locking portion formed at one end of the cylinder. If the other end of the cylinder is fixed to the housing accommodating the power piston at the stop position and the initial position of the input member is set, the initial position can be easily and accurately set. Accordingly, the input member can be securely locked to prevent the input member from falling off.

Further, as described in claim 3, the pressure adjusting means is formed in the power piston, and a damper chamber is formed in the power piston between the pressure adjusting means and the input member. If it is configured to communicate with the atmosphere via a throttle formed in the input member, it is possible to suppress a sudden increase in the stroke of the brake pedal at the time of additional depression during automatic braking operation, and to provide an appropriate operational feeling to the driver. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic brake device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the hydraulic pressure assist device in a state where a brake operation is not performed in one embodiment of the present invention.

FIG. 3 is a sectional view showing a state when the hydraulic brake device according to the embodiment of the present invention is assembled.

FIG. 4 is a cross-sectional view illustrating a state in which a hydraulic brake device according to another embodiment of the present invention is assembled.

FIG. 5 is a cross-sectional view showing a state of the hydraulic pressure assist device during automatic braking according to the embodiment of the present invention.

[Explanation of symbols]

10 master cylinder, 20 hydraulic assist device, 3
Brake pedal, 4 reservoir, 5, 6 on-off valve,
11, 12 master piston, 21 power piston,
22 plunger, 27 plug member, 28 guide member, 29 case, S1 to S9 seal member,
R1, R2 pressure chamber, R3 closed chamber, R4 drain chamber, R5 liquid supply chamber, R6 power chamber, R7 damper chamber

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Ishida 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin Seiki Co., Ltd. (72) Inventor Masaki 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin Seiki Co., Ltd. F term (reference) 3D048 BB27 BB54 CC10 GG05 GG16 GG22 GG36 HH15 HH16 HH18 HH39 HH42

Claims (3)

[Claims] 1. A master cylinder for driving a master piston forward in response to an operation of a brake operation member to boost brake fluid in a reservoir and output brake fluid pressure, and disposed behind the master piston, and a power chamber is disposed rearward. A hydraulic piston, an auxiliary hydraulic pressure source that boosts the brake fluid in the reservoir to a predetermined pressure and outputs power hydraulic pressure, and an auxiliary hydraulic pressure connected to the auxiliary hydraulic pressure source and connected to the reservoir. And a pressure regulating means for regulating the output power hydraulic pressure of the power source to a predetermined pressure and supplying the output power hydraulic pressure to the power chamber, wherein the hydraulic brake device is axially movable relative to the power piston. An input member that moves in accordance with the operation of the brake operation member, and a locking portion formed at one end;
A support member for fixing the other end to a housing that slidably accommodates the power piston, and a guide member for slidably supporting one end with respect to the support member and fixing the other end to the input member. A hydraulic brake device for a vehicle, wherein a position at which one end of the guide member is locked to a locking portion of the support member is set to an initial position of the input member. 2. A position where the support member is formed of a cylinder housing the input member and the guide member, and one end of the guide member is locked to a locking portion formed at one end of the cylinder.
The hydraulic brake device for a vehicle according to claim 1, wherein the other end of the cylindrical body is fixed to a housing that houses the power piston, and an initial position of the input member is set. 3. The pressure adjusting means is formed in the power piston, a damper chamber is formed in the power piston between the pressure adjusting means and the input member, and the damper chamber is connected to the input member. 2. The hydraulic brake device for a vehicle according to claim 1, wherein the hydraulic brake device is configured to communicate with the atmosphere via a throttle formed in the vehicle.