JPH05221308A - Braking force control device - Google Patents

Abstract

PURPOSE:To secure the seal of the brake liquid and the operating oil by a hydraulic control valve in a braking force control device for supplying the operating oil from an oil pressure source to a wheel cylinder through a hydraulic control valve to be controlled in response to the pressure of a master cylinder. CONSTITUTION:A first bellows 56c and a second bellows 56f, which are respectively formed by a first bellows 56a and a second bellows 56d and which are communicated with each other, are provided in adjacent to a master cylinder chamber 60 provided in the end of a hydraulic control valve 5, and the inside of the first bellows 56c and the second bellows 56f are filled with silicon to provide a transmitting means 56 for transmitting the pressure of the master cylinder through the silicon inside of both the chambers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking force control device for arbitrarily controlling the braking force applied to each wheel.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 3-92038.
No. 1 provides a braking force control device that can arbitrarily control the braking force applied to each wheel. This braking force control device uses the pressure generated by the master cylinder on the pressure increasing side of the spool, and uses the force from the actuator on the pressure reducing side of the spool to control the hydraulic pressure supplied from an external hydraulic pressure source. It controls the braking hydraulic pressure supplied to the wheel cylinders.

That is, since the hydraulic oil from the external hydraulic source can be supplied to the wheel cylinder according to the master cylinder pressure,
In addition to realizing a high boosting function, anti-skid (braking slip) control and traction control (driving slip) by electronically controlling the actuator
Control is also possible.

By the way, since this hydraulic control valve uses a spool, hydraulic oil having a viscosity higher than that of the brake fluid is used in order to reduce leakage. The seal material used for the system from the hydraulic source that uses hydraulic oil to the wheel cylinders via the hydraulic control valve and the seal material used for the system that uses the brake fluid from the master cylinder to the hydraulic control valve are I am using non-erodible ones,
If the liquids mix with each other, the durability against erosion may deteriorate.

Therefore, in the hydraulic control valve shown in FIG. 7 of the above-mentioned application, the brake fluid flows into the end face chamber formed in the end face of the spool and into which the working oil flows, and adjacent to the end face chamber and communicating with the master cylinder. A bellows was provided to seal the master cylinder chamber. By interposing a spring between the bellows and the end surface of the spool, the spool is pressed toward the pressure increasing side via the bellows and the spring according to the master cylinder pressure. By using the bellows, it is possible to provide a hydraulic control valve having a high responsiveness because it is possible to secure a higher sealing property as compared with the one using a fixed seal and to reduce sliding friction.

[0006]

However, even though the master cylinder chamber has a high pressure, the spool end face chamber has been drained and thus is at atmospheric pressure. Therefore, it is necessary for the bellows to ensure high durability. was there.
For this reason, in order to increase the durability of the bellows, the wall thickness must be necessarily increased, and if the wall thickness is increased, the responsiveness deteriorates.

The present invention has been made in view of the above problems, and an object thereof is to provide a braking force control device that achieves both the securing of sealing performance and the prevention of deterioration of responsiveness.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 is a master cylinder for generating a master cylinder pressure according to a pedaling force of a brake pedal,
A hydraulic pressure source, a wheel cylinder for respectively braking each wheel by the output hydraulic pressure from the hydraulic pressure source, and an output hydraulic pressure from the hydraulic pressure source, which is provided between the hydraulic pressure source and the wheel cylinder, are set according to the master cylinder pressure. A hydraulic control valve for controlling the control pressure is provided. The hydraulic control valve includes a spool for increasing / decreasing the control pressure by switching the oil passage, an actuator for applying a force to the spool in a direction to reduce the control pressure, and a spool. To the master cylinder pressure in the direction of increasing the control pressure with respect to the master cylinder pressure from the hydraulic oil and the transmission means for transmitting the output hydraulic pressure from the hydraulic pressure source. In a braking force control device having a first bellows for sealing a brake fluid that transmits to the transmission means, the transmission means includes a space between the first bellows and the spool. The second bellows is provided, to form a sealed fluid chamber and the second bellows and the first bellows, it is assumed that the master cylinder pressure is made to act on the spool through a fluid sealed in the fluid chamber.

In order to achieve the above object, the invention according to claim 2 is characterized in that a pressing member is provided on the first bellows, and the master cylinder pressure is applied to the spool via the pressing member. The braking force control device according to claim 1.

[0010]

According to the braking force control apparatus of the present invention, the output hydraulic pressure from the hydraulic pressure source increases the control hydraulic pressure to the spool by the force of the actuator that pushes the spool in the direction in which the hydraulic control valve reduces the pressure and the transmission means. Based on the balance with the master cylinder pressure acting in the directional direction, the pressure is output as the control pressure controlled while switching the oil passage by the spool to brake each wheel.
The transmission means causes the master cylinder pressure to act on the spool via the fluid enclosed in the fluid chamber formed by the first bellows and the second bellows. Therefore, when the first bellows breaks, the fluid in the fluid chamber mixes with the brake fluid, but the hydraulic oil and the brake fluid do not mix. On the other hand, when the second bellows breaks, the hydraulic oil mixes with the fluid in the fluid chamber, but the hydraulic oil and the brake fluid do not mix.

According to the braking force control device of the second aspect, in addition to the operation of the braking force control device of the first aspect, the second bellows is broken and the fluid in the fluid chamber leaks, and the master cylinder pressure is enclosed in the fluid chamber. Even if it is impossible to act on the spool via the fluid, the pressing member can push the spool in the pressure increasing direction.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall view showing a braking force control device of the first embodiment. This braking force control device extends from a master cylinder 2 that generates a master cylinder pressure PM in response to depression of a brake pedal 1 and a wheel cylinder 4 provided from the master cylinder 2 to a disc brake device 3 of each wheel. A brake fluid system 100, a hydraulic control valve 5 for adjusting the accumulator pressure PS from the hydraulic source 7,
It comprises a hydraulic oil system 101 leading to a booster 12 which makes the control pressure PC of the hydraulic control valve 5 a higher wheel cylinder pressure PW.

The hydraulic pressure source 7 comprises an oil pump 7a, a check valve 7b and an accumulator 7c,
The hydraulic oil is supplied from an accumulator oil passage 6 to an input port 5a of the hydraulic control valve 5 described later. Further, the TCS pressure PT, which is provided in the branch oil passage 6a of the accumulator oil passage 6 and has the accumulator pressure as a base pressure by opening the valve, transfers the TCS port 5b of the hydraulic control valve 5 described later to An electromagnetic switching valve 8 that operates on the pressure increasing side is provided.

The hydraulic control valve 5 connects and disconnects the accumulator oil passage 6 and the oil passage 9 leading to the booster 12,
A spool 51 that switches between communication and cutoff between the oil passage 9 and the drain 5j, and a proportional solenoid (actuator) that pushes the spool 51 in a direction that allows the oil passage 9 and the drain 5j to communicate with each other, that is, a direction that reduces the control oil pressure PC. ) 5
2 and a transmission means 56, which will be described later, that pushes the spool 51 in a direction in which the accumulator oil passage 6 and the oil passage 9 communicate with each other, that is, pushes in a direction in which the control hydraulic pressure PC is increased.

The body 50 forming the hydraulic control valve 5 includes:
An insertion hole 53 is bored in the longitudinal direction, and an input port 5a communicating with the annular groove 53a provided in the insertion hole 53 and a drain port 5d communicating with the annular groove 53d are provided. The output port 5c is provided between the annular grooves 53a and 53d.

The spool 51 is slidably inserted in the axial direction of the insertion hole 53. An annular groove 51a is formed in the center of the spool 51, and lands 51 are formed on both sides of the annular groove 51a.
b, a land 51c is formed. A diaphragm 510 is formed by the land 51b and the annular groove 53a.
By opening and closing, the input port 5a and the output port 5c are connected and disconnected. On the other hand, the land 51c and the annular groove 53d form a diaphragm 511, and the opening and closing of the diaphragm 511 connects and disconnects the output port 5c and the drain port 5d. or,
The land 51c on the right side of the figure has a larger diameter than the land 51b on the left side of the figure, and the insertion hole 53 also has a land 51c.
The diameter is changed according to b and 51c.

In order to close the diaphragm 510 and open the diaphragm 511, that is, to push the spool 51 in the right direction in the drawing,
When a current is applied to the solenoid 52a of the proportional solenoid 52, a plunger 52b, which receives a rightward force in the drawing, is brought into contact with the left end surface of the spool 51 in the drawing.

A spring 66 is press-fitted in an oil chamber 53g formed by the end surface of the spool 51 on the left side in the drawing and the insertion hole 53. The oil chamber 53g is connected to the tank 5j through the drain port 5d.

On the other hand, on the right end surface of the spool 51 in the figure,
A hole 51d is bored in the axial direction of the spool 51 with the end face closed, and a pilot pin 54 slidable in the axial direction is inserted into the hole 51d. This pilot pin 54
Part of the pedestal 65 protrudes from the hole 51d and is located in the oil chamber 53f formed by the end surface of the spool 51 and the insertion hole 53.
It is slidably fitted in the recess of the. The oil chamber 53f is connected to the tank 5j through the drain port 5d.

A chamber 51e formed by the hole 51d and the pilot pin 54, and an annular groove 53b provided in the insertion hole 53.
And a communication hole 51h communicating with the annular groove 53b.
Is provided with a TCS port 5b.

An oil chamber 61 communicating with the oil chamber 53f is formed on the opposite side of the oil chamber 53f from the spool 51, and a master cylinder chamber 60 is formed between the oil chamber 61 and the cutoff wall 62. There is. The branch oil passage 10a of the oil passage 10 extending from the master cylinder 2 to the wheel cylinder 4 is connected to the port 5e provided in the master cylinder chamber 60.

The transmission means 56 includes the master cylinder chamber 6
A first bellows chamber 56c formed on the 0 side, a second bellows chamber 56f formed on the chamber 61 side, and a first bellows chamber 56
First bellows 56a and plate 56b made of metal forming c
And a second metal bellows 56d and a plate 56e which form the second bellows chamber 56f. First bellows chamber 5
6c and the second bellows chamber 56f communicate with each other through a communication hole 64 provided in the blocking wall 62, and silicon (fluid) is sealed inside. This silicon is used in the first bellows chamber 56c and the second bellows chamber 56c.
It moves according to the volume change of the bellows chamber 56f. Since silicon is unlikely to cause a chemical reaction, it does not corrode the seal members of the respective systems even if mixed with the brake fluid and the hydraulic oil.

A plate 56b is provided in the first bellows chamber 56c.
To the second bellows chamber 56f.
A pressing member 58 is provided inside the plate 56e with a gap.

A spring 63 is pressed between the plate 56b and the master cylinder chamber 60, and a spring 55 is pressed between the plate 56e and the pedestal 65.

The hydraulic booster 12 includes the step plunger 1
The control hydraulic chamber 122 communicating with the output port 5c and the input port 12a communicating with the oil passage 9 on the large diameter side of 21.
Is formed, a wheel cylinder pressure chamber 123 communicating with the output port 12b is formed on the small diameter side of the step plunger 121, and the step plunger 121 is provided with a return spring 124.
Is urged to the left in the drawing by. The wheel cylinder pressure chamber 123 is communicated with the master cylinder 2 by the master cylinder pressure port 12c.

Further, the pilot switching valve 1 provided in the oil passage 10
7 is provided in the middle of the oil passage that connects the master cylinder pressure oil passage 10 and the master cylinder pressure port 12c.
The hydraulic pressure in the oil passage 9 is used as a pilot pressure to connect and disconnect the master cylinder 2 and the master cylinder port 12c.

The proportional solenoid 52 of the hydraulic control device and the solenoid 81 of the electromagnetic switching valve 8 are drive-controlled by a command from the brake controller 13, and the brake controller 13 has a longitudinal acceleration sensor 14 as a sensor for obtaining input information. The wheel speed sensor 15, the master cylinder pressure sensor 16 and the like are connected.

That is, with the drive control by the brake controller 13, boost control for increasing the master cylinder pressure, ABS control for preventing wheel lock during braking, and TCS control for suppressing drive wheel slip at the time of starting or sudden acceleration. Is done. It is also possible to control the active brake or the like so that a desired yaw rate can be obtained by producing a braking force difference between the left and right wheels.

The operation of the braking force control system of the first embodiment having the above construction will be described below.

(A) During non-braking and non-controlling There is no depression of the brake pedal 1 and the master cylinder pressure P
When M is zero, the spring force F2 of the spring 63 acting leftward in the figure is balanced with the spring force F1 of the spring 66 acting rightward in the figure and the force FS generated by the proportional soleinoid 52. The spool 51 is stopped, the throttle 511 is opened, and the control pressure PC is the drain pressure.

(B) During normal braking When the brake pedal 1 is depressed, a master cylinder pressure PM is generated in the master cylinder 2 in accordance with the depression force of the brake pedal 1 and is supplied to the master cylinder chamber 60.
Therefore, the first bellows 56a shrinks, and the liquid in the first bellows chamber 56c passes through the communication hole 64 and the second bellows chamber 56f.
Move to. Therefore, the second bellows 56d extends and pushes the spool 51 leftward in the drawing via the spring 55 and the pedestal 65. At this time, the force pushing the spool 51 to the left in the figure is F2 + A4.PM, where A4 is the pressure receiving area of the plate 56b.

When the above force acts on the spool 51, the spool 51 moves leftward in the drawing to open the throttle 510, and the accumulator pressure PS changes from the input port 5a to the output port 5c.
Flow to. Since the spool 51 is a two-stage spool having a step, the control oil pressure PC of the output port 5c is
This causes a force to move the spool 51 to the right. The force at that time is (A1−A2) · PC, where A1 is the large-diameter cross-sectional area and A2 is the small-diameter cross-sectional area.

At this time, the balance of the spool 51 is (A1-A2) .PC = F2 + A4.PM-F1.

Therefore, the control oil pressure PC is proportional to the master cylinder pressure PM and is the sum of the spring force (F2-F1).

Next, when a current is applied to the solenoid 52a,
A force FS proportional to the current is generated in the plunger 52b and pushes the spool 51 to the right in the figure. Spool 5 at this time
The balance of 1 is (A1 -A2) .PC = A4.PM + F2 -F1 -FS, and the control oil pressure P is in accordance with the current to the solenoid 52a.
C will be controlled to increase or decrease.

By the way, when the control oil pressure PC is generated in accordance with the brake operation, the pilot switching valve 17 having the control oil pressure PC as the pilot pressure is switched to the side that shuts off the oil passage 10, thereby the control oil pressure PC. Is a hydraulic booster 1
2 is supplied to move the step plunger 121 to the right in the drawing. When the step plunger 121 moves to the right in the figure, the wheel cylinder pressure chamber 123 is pressurized, so that the wheel cylinder pressure PW is equal to the area ratio (A
5 / A6: A5 is pressurized with a large area and A6 with a small area).

By the above operation, the wheel cylinder pressure PW
Is controlled by the following equation.

PW = {A5. (A4.PM + F2-F1
-FS)} / {A6. (A1-A2)} When this is illustrated, the characteristic shown in FIG. 2, that is, when the solenoid current is zero, the pressure boosting ratio becomes the largest and the characteristic (a) is exhibited. When the solenoid current is increased, the wheel cylinder pressure PW is reduced in proportion to the solenoid current, resulting in the characteristic (b).

Therefore, the wheel cylinder pressure characteristic with respect to the master cylinder pressure is set in the brake controller 13 according to the vehicle state by a function or a map, and based on the information indicating the vehicle state and the information from the master cylinder pressure sensor 16. By controlling the solenoid current, the wheel cylinder pressure can be obtained with an arbitrary boosting characteristic according to the vehicle state. That is, a boost control function having a high degree of freedom is exerted instead of a unique boost ratio.

(C) During ABS control During sudden braking or when wheel locking is likely to occur on the bottom μ road,
An ABS operation for preventing wheel lock is performed by a control command from the ABS control unit of the brake controller 13 to the proportional solenoid 52.

That is, as the normal boosting characteristic, for example, if the solenoid current is set so as to obtain the characteristic (e), a pressure increase up to the characteristic (a) and a pressure decrease up to the characteristic (b) are performed. The slip ratio of each wheel is calculated from the vehicle speed information obtained by integrating the input signal from the longitudinal acceleration sensor 14 and the wheel speed information obtained from the wheel speed sensor 15, and the slip ratio is the optimum slip ratio. The wheel cylinder pressure PW can be increased, maintained, or reduced as shown in the range.

That is, the ABS for improving the vehicle stability during braking.
The function can be achieved with a sufficient increase or decrease of the wheel cylinder pressure PW.

(D) During TCS control When a drive wheel slip occurs due to a sudden accelerator pedal operation during starting or sudden acceleration, the brake controller 1
The TCS operation for suppressing the drive wheel slip is performed by the control command to the proportional solenoid 52 and the ON command to the solenoid 81 from the TCS control unit 3 of FIG.

That is, when the ON command is output to the solenoid 81, the electromagnetic switching valve 8 is opened, so that the accumulator pressure PS becomes the TCS pressure PT and the hydraulic control valve 5 is operated.
Is supplied to the chamber 51e from the TCS port 5b. This T
The CS pressure PT acts on the pilot pin 54 and pushes the pilot pin 54 to the right in the figure. However, since the pilot pin 54 is in contact with the base 65, the spool 51 is moved leftward in the drawing. At this time, the balance of the spool 51 becomes (A1 -A2) .PC = A3 .PT -F1 -FS + F2, where A3 is the cross-sectional area of the pilot pin 54.

Therefore, although the master cylinder pressure PM is not generated, the control oil pressure PC varies from the maximum pressure determined by the TCS pressure PT to the pressure obtained by reducing the force FS proportional to the solenoid current according to the solenoid current. It can be controlled arbitrarily. The characteristic is the characteristic shown in FIG.

That is, the braking force can be applied to the drive wheels in accordance with the amount of the drive wheel slips, and the TCS function of effectively suppressing the drive wheel slips is exhibited.

(E) When the electronic control system and the hydraulic system fail When the electronic control system related to the brake controller 13 fails, the current to the solenoid 52a is made zero and the electromagnetic opening / closing valve 8 is closed.

Therefore, the force acting on the spool 51 is (A1-A2) .PC = A4.PM + F2-F1. Therefore, although ABS operation and TCS operation cannot be performed, the characteristic (a) of FIG. 2 is retained. To be done. That is, the state of maximum capacity of the brake boosting performance is ensured, and the braking action having the boosting function is guaranteed.

Due to a failure of the oil pump 7a or the like, the hydraulic pressure source 7
Therefore, when the hydraulic source pressure fails such that the accumulator pressure PS is not, the control hydraulic pressure PC is not generated by the hydraulic control valve 5. When the control oil pressure PC is not generated in this manner, the pilot switching valve 17 having the control oil pressure PC as the pilot pressure is switched to the communication side as shown in FIG. 1, so that the master cylinder pressure PM is increased. The wheel cylinder pressure PW is used as it is, and the wheel cylinder 4 of each wheel is
Granted to.

(F) When the bellows breaks Although the first bellows 56a does not expand and contract according to the master cylinder pressure when the first bellows 58 breaks, the master cylinder pressure is transferred to the second bellows chamber 56f through the communication hole 64. Is applied, the second bellows 56c extends to the spool 51 side. Therefore, boost function, ABS function, T
It does not impair the CS function at all.

When the second bellows 56d is broken, the first bellows 56a contracts according to the master cylinder pressure, but the second bellows 56d does not expand. However, the pressing member 5
The plate 56e is pressed by 8 toward the spool side. Therefore, the boosting function, ABS function, and TCS function are not impaired at all.

That is, even if either the first bellows 56a or the second bellows 56d breaks, the hydraulic oil and the brake fluid do not mix with each other, and at the time of breaking, the boost control function, the ABS control function, and the TCS. It can support all of the functions and does not impair responsiveness as compared with one that uses a single bellows to increase the wall thickness to ensure durability.
Further, since the first bellows 56a and the second bellows 56d are hardly broken at the same time, a reliable sealing property can be secured.

Next, a second embodiment of the present invention will be described with reference to FIG.

In this embodiment, the volume of the first bellows chamber 56c of the hydraulic control valve 5 used in the first embodiment is increased. That is, the blocking wall 62 is provided with the first bellows 156a having a larger internal volume than the first bellows 56a, and the plate 56
A plate 156b having a larger cross-sectional area than b is fixed. The first bellows chamber (fluid chamber) 1 formed by this
56c and the second bellows chamber 56f are communicated with each other through a communication hole 64. The rest of the configuration is the same as that of the first embodiment, so its explanation is omitted.

With the above structure, the braking force control system of the second embodiment has (A), (B), (C), shown in the first embodiment.
In addition to the functions of (D), (E), and (F), the first bellows 1
When 56a is broken, the master cylinder pressure directly acts on the plate 56e and pushes the spool 51 in the pressure increasing direction via the spring 55. At this time, the pressure receiving area of the plate 56e is equal to the plate 156.
Since it is smaller than the pressure receiving area of a, the relationship between the master cylinder pressure and the wheel cylinder pressure is as shown in FIG. That is, although the characteristic is normally shown by the solid line, when the first bellows 156a is broken, the increase rate of the wheel cylinder pressure PW with respect to the master cylinder pressure PM is lower as compared with the normal characteristic as shown by the broken line. It becomes a characteristic.
Therefore, the driver can feel the breakage of the first bellows 156a as a change in the pedaling force of the brake pedal 1, and can know the abnormality of the brake device.

Next, a third embodiment of the present invention will be described with reference to FIG.

In this embodiment, in addition to the structure described in the first embodiment, the driver warning lamp 11 lights up to notify the breakage of the first bellows 56a or the second bellows 56d. That is, the blocking wall 62 is formed of an insulator 62a, a metal disc 62b that does not contact the metal pressing member 58 is fixed to the metal first bellows 56a side, and the metal second bellows 56d side is fixed. Metal disk 6 that does not contact the pressing member 58
2c is fixed, and these insulators 62a and disks 62
b and the disc 62c are fitted to the body 50 via an insulator 62d. The positive electrode side of the battery 10 is connected to the disk 62b, and the negative electrode side of the battery 10 is connected to the disk 62c via the warning light 11. The warning light 11 is provided inside the vehicle and can be confirmed by the driver when it is turned on.

With the above-mentioned structure, the braking force control system of the third embodiment has (A), (B), (C), which are shown in the first embodiment.
In addition to the functions of (D), (E), and (F), the first bellows 5
8 or the second bellows 56 is broken, the pressing member 58
And the plate 56e come into contact with each other, and the disc 62c and the second bellows 56
d, the plate 56e, the pressing member 58, the plate 56b, the first bellows 56a, and the disk 62b are energized, and the warning light 11 is turned on, so that the driver can know the abnormality of the brake device.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

Similar to the third embodiment, the present embodiment notifies the breakage of the first bellows 56a or the second bellows 56d by lighting the driver warning light 11 in addition to the structure described in the first embodiment. That is, the blocking wall 6 used in the first embodiment
The contact portion of the second pressing member 58 is formed of an insulator 62f, the pressing member 58 is also formed of an insulator, and a metal piece 58f is provided at the tip end portion of the pressing member 58.
f is connected to the positive electrode of the battery 10 by the covered wiring 10a provided inside the pressing member 58 and the plate 56b, and the blocking wall 62 is connected to the negative electrode of the battery 10 by the wiring 10b via the warning light 11. is there.

With the above-mentioned structure, the braking force control device of the fourth embodiment has (A), (B), (C), shown in the first embodiment.
In addition to the functions of (D), (E), and (F), the first bellows 5
When the 6a or the second bellows 56d breaks, the metal 58
Since the f and the plate 56a come into contact with each other and the warning light 11 is turned on, the driver can know the abnormality of the brake device.

Next, a fifth embodiment of the present invention will be described with reference to FIG.

In this embodiment, the master cylinder chamber 60 and the first bellows chamber 56c of the hydraulic control valve 5 used in the first embodiment are used.
The shape of is changed. That is, the master cylinder chamber 160 communicated with the master cylinder 2 is formed by the first bellows 256a and the plate 256b fixed to the first bellows 256a, and the communication hole 64 is communicated with the second bellows chamber 56f on the outer side thereof.
A fluid chamber 256c having silicon sealed therein is formed. Further, a spring 163 is pressure-installed between the plate 256b and the blocking wall 62, and the plate 256b is provided with a pressing member 58 which passes through the blocking wall 62 and is loosely inserted into the second bellows chamber 56f. The other structure is similar to that of the first embodiment, and the description thereof is omitted.

With the above structure, the plate 256b is pressed leftward in the drawing in accordance with the master cylinder pressure, and the first bellows 256 is pressed.
a grows. The silicon in the fluid chamber 256c moves to the second bellows chamber 56f through the communication hole 64 to compensate for the increased volume of the master cylinder chamber 160. For this reason, the second bellows 56d extends leftward in the figure, so that the spool 51 is pushed leftward in the figure via the spring 55. That is, as in the first embodiment, the spool 51 can be pushed leftward in the drawing in accordance with the master cylinder pressure, and (A), (B), (C), (D), () shown in the first embodiment. It has the action and effect of E).

(F) When the bellows ruptures When the first bellows 256a ruptures, the first bellows 256a does not expand or contract according to the master cylinder pressure, but the master cylinder pressure is fed into the second bellows chamber 56f through the communication hole 64. Is applied, the second bellows 56d extends toward the spool 51 side. Therefore, the boosting function, ABS function, and TCS function are not impaired at all.

On the other hand, when the second bellows 56d is broken,
The first bellows 256a expands according to the master cylinder pressure, but the second bellows 56d does not expand. However, the pressing member 58 presses the plate 56e toward the spool.
Therefore, the boosting function, ABS function, and TCS function are not impaired at all.

That is, the first bellows 256a or the second bellows 256a
Even if one of the bellows 56d breaks, the hydraulic oil and the brake fluid do not mix with each other, and even when the bellows 56d breaks, the boost control function, the ABS control function, and the TCS function can all be supported. Responsiveness is not impaired as compared with a bellows which is thickened to ensure durability.
Further, since the first bellows 256a and the second bellows 56d are hardly broken at the same time, a reliable sealing property can be secured.

Next, a sixth embodiment of the present invention will be described with reference to FIG.

In this embodiment, the oil chamber 53f of the first embodiment is used.
Is provided adjacent to the oil chamber 161 and a master cylinder chamber 160 communicated with the master cylinder 2 is formed by the first bellows 256a and the plate 256b, and the second bellows with silicon sealed inside is formed. The chamber (fluid chamber) 156f is formed by the second bellows 156d and the plate 156e. Further, the pressing member 158 is fixed to the plate 256b with a gap from the plate 156e. The other structure is similar to that of the first embodiment, and the description thereof is omitted.

With the above structure, the plate 256b is pressed leftward in the drawing in accordance with the master cylinder pressure, and the first bellows 2
56a extends to the left in the figure. Therefore, the second bellows 1
56d extends to the left in the drawing to compensate for the volume change of the master cylinder chamber 160, and pushes the spool 51 to the left in the drawing via the spring 55. That is, as in the first embodiment, the spool 51 can be pushed leftward in the drawing in accordance with the master cylinder pressure, and (A), (B) shown in the first embodiment,
It has the functions and effects of (C), (D), and (E).

(F) When the bellows breaks When the first bellows 258 breaks, the first bellows 256a does not expand or contract according to the master cylinder pressure, but the master cylinder pressure acts directly on the second bellows chamber 156f. The second bellows 156d extends leftward in the figure, and pushes the spool 51 leftward in the figure via the spring 55. Therefore, boost function, ABS function, TCS
There is no loss of functionality. Further, at this time, the pressure receiving area is changed, so that the driver does not need to change the first area as in the second embodiment.
The break of the bellows 256a can be felt as a change in the pedaling force of the brake pedal 1, and the abnormality of the brake device can be known.

On the other hand, when the second bellows 156d is broken, the first bellows 256a expands according to the master cylinder pressure, but the silicon in the second bellows chamber 156f leaks into the chamber 161, so that the second bellows 156d does not expand. However, the pressing member 158 causes the plate 156 to
Since e is directly pressed to the spool 51 side, a boosting function, A
The BS function and the TCS function are not impaired at all.

That is, the first bellows 256a or the second bellows
Even if either of the bellows 156d breaks, the hydraulic oil and the brake fluid do not mix with each other, and even when the bellows 156d breaks, it is possible to support all of the boost control function, the ABS control function, and the TCS function. Responsiveness is not impaired as compared with a bellows which is thickened to ensure durability. In addition, the first bellows 256a and the second bellows 156d
Since and are almost never broken at the same time, a reliable sealing property can be secured.

Also, in this embodiment, the second bellows chamber 156f is used.
Since the master cylinder chamber 160 is formed therein, the volume of the fluid chamber 156f can be reduced and the size of the hydraulic control valve 5 itself can be reduced.

Next, a seventh embodiment of the present invention will be described with reference to FIG.

In this embodiment, a fluid chamber 360 having silicon sealed therein is formed adjacent to the oil chamber 53f, and the first bellows chamber 160 communicating with the master cylinder is formed in the fluid chamber 360 with the first bellows 256a plate. Formed with 256b,
Second bellows chamber 2 communicating with the oil chamber 53f through the communication passage 264
56f is formed by the second bellows 256d and the plate 256e. A shaft member 555 is provided so that the pedestal 65 can be pressed according to the reduction of the second bellows chamber 256f. This shaft member has a spring 55a in the right direction in the drawing.
Being pushed by. Also, the plate 256b has a plate 256e.
A pressing member 158 is provided with a gap. The other structure is similar to that of the first embodiment, and the description thereof is omitted.

With the above structure, the plate 158a is pressed leftward in the drawing in accordance with the master cylinder pressure, and the first bellows 2
Reference numeral 58 extends leftward in the figure. Therefore, the second bellows 15
Reference numeral 6 extends to the left in the drawing to compensate for the volume change of the master cylinder chamber 160, and the shaft member 555 pushes the spool 51 in the pressure increasing direction via the pedestal 65. That is, as in the first embodiment, the spool 51 can be pushed to the left in the drawing in accordance with the master cylinder pressure, as shown in the first embodiment (A),
The functions and effects of (B), (C), (D), (E), and (F) are provided.

(F) When the bellows breaks When the first bellows 258 breaks, the master cylinder pressure directly acts on the second bellows chamber 356, and the second bellows 256
Since d contracts leftward in the figure, the shaft member 555 can be pushed leftward in the figure, and the spool 51 is pushed leftward in the figure. Therefore, the boosting function, ABS function, and TCS function are not impaired at all.

When the second bellows 256d is broken, the second bellows chamber 256f is not reduced in order to compensate the volume of the fluid chamber 360, but the pressing member 158 causes the plate 25 to shrink.
The pressing member 555 can be pushed leftward in the figure via 6e, and the spool 51 is pushed leftward in the figure. Therefore, the boosting function, ABS function, and TCS function are not impaired at all. In addition, the first bellows 256a and the second bellows 256d
Since and are almost never broken at the same time, a reliable sealing property can be secured.

[0081]

As described above, according to the first aspect of the present invention, even if either one of the first bellows and the second bellows is broken, the brake fluid and the hydraulic oil do not mix with each other, which is reliable. The sealability can be secured, and since it is not necessary to make the first bellows and the second bellows thicker than necessary, deterioration of responsiveness can be prevented.

The invention according to claim 2 is the above-mentioned claim 1.
In addition to the effects of the invention described above, even if the second bellows is broken, the spool can be pushed in the pressure increasing direction via the pressing member, so that braking force control can be ensured.

[Brief description of drawings]

FIG. 1 is an overall view of a braking force control device showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a master cylinder pressure and a wheel cylinder pressure of the braking force control device shown in FIG.

FIG. 3 is a sectional view of a hydraulic control valve used in a second embodiment of the present invention.

FIG. 4 is a graph showing characteristics of a braking force control system according to a second embodiment of the present invention during normal operation and when the second bellows breaks.

FIG. 5 is a sectional view of a hydraulic control valve used in a third embodiment of the present invention.

FIG. 6 is a sectional view of a hydraulic control valve used in a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a hydraulic control valve used in a fifth embodiment of the present invention.

FIG. 8 is a sectional view of a hydraulic control valve used in a sixth embodiment of the present invention.

FIG. 9 is a sectional view of a hydraulic control valve used in a seventh embodiment of the present invention.

[Explanation of symbols]

1 ... Brake pedal, 2 ... Master cylinder, 4 ... Wheel cylinder, 5 ... Hydraulic control valve, 7 ... Hydraulic source, 51 ... Spool, 52 ... Proportional solenoid (actuator), 5
6 ... Transmission means, 56a, 156a, 256a ... First bellows, 56f, 156f, 256f ... Second bellows, 5
8, 158 ... Pressing members, 56c, 56f, 156c, 2
56c, 156f, 360 ... Fluid chamber.

Claims (2)

[Claims] 1. A master cylinder for generating a master cylinder pressure according to a pedaling force of a brake pedal, a hydraulic pressure source, a wheel cylinder for respectively braking each wheel with an output hydraulic pressure from the hydraulic pressure source, the hydraulic pressure source and the wheel. And a hydraulic control valve that is provided between the cylinder and a hydraulic pressure control valve that controls the output hydraulic pressure from the hydraulic pressure source to a control pressure that corresponds to the master cylinder pressure. And a transmission means for applying the master cylinder pressure to the spool in a direction to increase the control pressure, and a transmission means for applying a force to the spool in a direction to reduce the control pressure. A first vero that seals the hydraulic fluid transmitting the output hydraulic pressure from the hydraulic pressure source and the brake fluid transmitting the master cylinder pressure from the master cylinder The braking force control device having a's, the transmission means, the second bellows is provided between the spool and the first bellows, the this second bellows first
A braking force control device characterized in that a fluid chamber sealed with a bellows is formed, and the master cylinder pressure is made to act on a spool via a fluid sealed in the fluid chamber. 2. The braking force control device according to claim 1, wherein a pressing member is provided on the first bellows, and the master cylinder pressure is applied to the spool through the pressing member.