JPH02303966A - Brake fluid pressure generating device - Google Patents

Abstract

PURPOSE:To display a required effect of power assistance without providing a vacuum booster by providing a booster piston, which is actuated by a pressure of fluid supplied from an auxiliary fluid pressure source to increase step-in force of a brake pedal, in a master cylinder. CONSTITUTION:A tandem master cylinder 1 in an X-piping two-system brake device is formed by fitting a primary piston 3 and a secondary piston 4 into a housing 2, and wheel cylinders 8, 9 of right front and left rear wheels are connected to a pressure fluid chamber 5 partitioned by these pistons, while wheel cylinders 13, 14 of left front and right rear wheels are connected to a pressure fluid chamber 6. Here a hydrobooster device 100 is provided in an inner rear part of the housing 2. This booster device 100 is constituted by providing the first cylindrical booster piston 82 secured to the piston 3, second booster piston 83 fitted with a play to the periphery of the piston 3 and a reaction piston 84 insertion-fitted into the first booster piston 82.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a brake fluid pressure generating device that increases the brake pedal depression force when braking a vehicle.

(Prior Art) A brake fluid pressure control device for a vehicle normally uses two pistons to control the fluid pressure of two systems of brake equipment. The hydraulic chamber and the wheel cylinder are connected by a liquid passage.

The piston and brake pedal are connected via a vacuum booster, which is a booster that utilizes the negative pressure of the engine.

In such a configuration, when the brake pedal is operated, a force several times the brake pedal depression force is generated in the vacuum booster, and by operating the piston with this force, the hydraulic pressure in the hydraulic pressure chamber of the master cylinder is applied to the wheel. The hydraulic pressure is transmitted to the cylinder, and the hydraulic pressure inside the wheel cylinder increases to apply braking force to the wheels.

However, since the vacuum booster is large and expensive, it not only occupies a limited space in the engine room, but also requires heavy gf and increases in price.

(Objective of the Invention) Therefore, the object of the present invention is to provide a small, lightweight, and inexpensive brake fluid pressure generating device that can exert the same boosting effect as a vacuum booster without providing a vacuum booster. be.

(Structure of the Invention) The present invention is characterized in that the master cylinder includes a booster piston that is operated by hydraulic pressure supplied from an auxiliary hydraulic pressure source to further increase the brake pedal depression force.

(Example) Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the overall configuration of an embodiment of the brake fluid pressure control device according to the present invention, which is equipped with an anti-lock control function for a front-wheel drive vehicle having a cross-piping type (x-piping) type two-system brake device. The type master cylinder l includes a housing 2 consisting of two housing parts 2a and 2b, front and rear (left and right in FIG.
The hydraulic pressure chambers 5, whose hydraulic pressures are controlled by the primary piston 3, form hydraulic chambers 5.6 whose hydraulic pressures are controlled by the pistons 3.4, respectively.
The wheel cylinder 8 of the front right wheel FR is connected to the wheel cylinder 8 of the right front wheel FR via the liquid passage 7 in which a hold valve HVI, which is a normally open solenoid valve, is provided in the middle.
It is further connected to the wheel cylinder 9 of the left rear wheel RL. These wheel cylinders 8.9 are connected to the reservoir II via a liquid passage IO in which a decay valve DVI consisting of a normally closed T4 magnetic valve is provided.

Similarly, the hydraulic pressure chamber 6, whose hydraulic pressure is controlled by the secondary piston 4, is connected to the left front wheel F via a liquid passage 12 in which a hold valve HV2 consisting of a normally open single magnetic valve is provided.
It is connected to the wheel cylinder 13 of the L wheel, and further connected to the wheel cylinder 14 of the right rear wheel RR. These wheel cylinders I3.14 are connected to the reservoir 11 via a liquid passage 15 in which a decay valve DV2, which is a normally closed electromagnetic valve, is provided in the middle.

Valve chambers 18,19 each having an opening 16,17 communicating with the hydraulic pressure chamber 5.6 are formed in the housing portion a of the master cylinder l, and these valve chambers I8 and 9 are located in the housing portion. 2a are connected to each other via passages 20, and the valve chambers 19 are connected to passages 21 and 2a.
The suction port of the hydraulic pump 23 is connected to the discharge port of the hydraulic pump 23, which is an auxiliary hydraulic pressure source, through the reservoir 1.
Connected to 1. In the valve chambers 18, 19, there are provided valves aJI 26, 27, which will be described later, each having an intake valve 31, 32 which also serves as a check valve. The hydraulic pump 23 is operated at least during anti-lock control.

On the other hand, a hydro booster device 200 operated by brake fluid pressure is provided in a housing portion 2b connected to the rear (right side in FIG. 1) of the housing portion 2a. This booster device 100 includes a cylindrical first booster piston 8 fixed to the right end of the primary piston 3.
2, a cylindrical second booster piston 83 slidably provided on the outer periphery of the primary piston 3, and a rear axial run piston 84 slidably provided coaxially within the first booster piston 82. There is.

FIG. 7 is an enlarged cross-sectional view showing the configuration of the booster device W 100, in which the rear axle piston 84 incorporates a booster valve 85 that is movable in the axial direction of the master cylinder l, and this booster valve 85 is a valve. It is urged toward the primary piston 3 by a spring 86.

The primary piston 3 has a reservoir 1 along its axis.
A liquid passage 57 communicating with the L liquid distribution passage 57 is formed, and when the first booster piston 82 moves to the left in the figure, the booster valve 85 closes the L liquid distribution passage 57.

A bushing rod 38 shown in FIG. 1 is connected to the right end of the rear axial piston 84. Engagement step portions 84a and 82a are formed on the outer circumference of the rear axle piston 64 and the inner circumference of the first booster piston 82, respectively, so as to face each other so as to maintain a predetermined distance when the brake pedal 37 is not depressed. There is. Rear axial piston 8
4 and the first booster piston 82, a spring 87 urges the re-engaging step portions 84a, 82a in a direction away from each other.

The inner circumference of the housing portion 2b of the master cylinder 1 is formed with a large diameter portion that opens toward the housing portion 2a.
A second booster piston 83 is housed in this large diameter portion. An engagement protrusion 83b is formed at the right end of the inner circumference of the second booster piston 83, and this engagement protrusion 83b is connected to the engagement protrusion 82 formed at the left end of the outer circumference of the first booster piston 82.
b. Therefore, the primary piston 3 and the first booster piston 82 fixed to the primary piston 3 move together as the second booster piston 83 moves to the left in response to brake fluid pressure. There is. The second booster piston 83 has a pressure-receiving stepped portion 83c facing right in the figure and mainly receiving hydraulic pressure.
A boost hydraulic pressure chamber 88 is formed to the right of this stepped portion 83c.

The primary piston 3 and the secondary piston 4 shown in FIG. 1 have cylindrical intake sleeves 33 for operating the intake valves 31 and 32, respectively.
．． 34 are respectively fixed facing into the hydraulic pressure chamber 5.6. Primary piston 3 and secondary piston 4
has built-in center valves 35 and 36 that are movable in the axial direction of the master cylinder 1 relative to the pistons 3 and 4, respectively, and when the brake pedal 37 is not depressed, it is connected to the brake pedal 37. In the state shown in FIG. 1 in which the bushing rods 3 and 8 are not pressing the primary piston 3, the hydraulic chamber 5.6 is in the closed position, the center valve 35.36, and the communication passage 39.3 in the piston 3.4. 40, communicating with the reservoir 11 via annular chambers 41.42 and liquid passages 43.44, respectively, formed around the piston 3.4. Further, the boost hydraulic pressure chamber 88 shown in FIG.
It communicates with a liquid passage 54 leading to a check valve 90, which will be described later, through a boat 53 formed in the
It communicates with the reservoir 11 through 7.

When the brake pedal 37 is depressed in FIG. 1, the bushing rod 38 is actuated and the rear axle piston 84 is pressed. As a result, as is clear from FIG. 7, the rear axial piston 84 moves to the left while compressing the spring 87, and the booster valve 85 closes the fluid passage 57 of the primary piston 3, thereby causing the boost hydraulic pressure chamber. 88 and the server 11 are cut off.

Next, the engagement step 84 a provided in an annular shape on the rear axle piston 84 is connected to the engagement step 8 on the first booster piston 82 side.
2a, and when the brake pedal 37 is further depressed, the first booster piston 82 and the primary piston 3 fixed to the left side of the first booster piston 82 move against the rear axle piston 8.
4 to the left in FIG.

When the primary piston 3 moves to the left in FIG. 1, the center valve 35 moves to the closed position to hydraulically shut off the hydraulic chamber 5 and the reservoir 11.

Therefore, the hydraulic pressure in the hydraulic chamber 5 increases, and the brake fluid in the hydraulic chamber 5 is supplied to the wheel cylinders 8.9 through the open hold valve HVI, and the wheels FR and RL is braked. As the hydraulic pressure within the hydraulic chamber 5 increases, the secondary piston 4 is actuated and the center valve 36 is moved to the closed position, thereby hydraulically shutting off the hydraulic chamber 6 and the reservoir 11. Therefore, the hydraulic pressure in the hydraulic chamber 6 also increases, and the brake fluid in the hydraulic chamber 6 is supplied to the wheel cylinders 13, 14 through the open hold valve HV2, and the brake fluid in the hydraulic chamber 6 is supplied to the wheel cylinders FL of the other brake system. ,RF? is braked.

The positional relationship and operation between each member are determined by a stop bolt 45.4 with a center valve 35.36 at one end.
6, stop bushings 47.48 respectively engaged with the heads 45a and 46a at the other ends of these stop bolts 45.46, and compressed between the stop bushings 47.48 and the intake sleeves 33.34. This is accomplished by springs 49, 50 and 51, 52 which bias the center valves 35, 36, respectively, into the closed position.

A relief valve 22 is disposed in a liquid passage 21 that connects the hydraulic pump 2'3 and the valve chamber 19.

As shown in FIG. 8, this relief valve 22 includes a piston 22a containing a valve spring 22b and a ball valve 22c, and a piston 22a that is biased against the discharge hydraulic pressure of a hydraulic pressure pump 23. A relief spring 22f that opens the ball valve 22C, a valve rod 22d that protrudes into the piston 22a to open the ball valve 22C, and a valve rod 22d that is connected to the end of the piston 22a (the right end in FIG. 8) and moves integrally with the piston 22a. piston 22
h, and a spring 22j for integrally moving the piston 22a and the piston 22h.

The relief spring 22f is compressed between the spring seat 22e attached to the piston 22a and the case 22m, and the valve rod 22d is attached to the piston 22a so as not to hinder the movement of the piston 22a.
It is accommodated in a groove 22g formed in the groove 22g, and is adapted to be received in contact with a part of the case 22m when the ball valve 22c is engaged with the ball valve 22c. The spring 22j is compressed between an opening at the rear end (right end in FIG. 8) of the piston 22h and a part of the case 22m. A piston chamber 22k formed by a part of the case 22m and the back of the piston 22h is provided at the rear end of the relief valve 22 (the right end in FIG. 8). The hydraulic pressure in the hydraulic pressure chamber 6 of the master cylinder is applied through the opening 22n.

A switch 70 made of a microsinch is provided in a part of the case 22m of the relief valve 22 (the right side in FIG. 8). This switch 70 has two fixed contacts 70
a, 70b, and a movable contact 70C, the movable contact 70
c is connected to the electric wire R (not shown). Further, one fixed contact 70a is connected to a motor 71 that drives the hydraulic pump 23, and the other fixed contact 70b is not connected. When the actuator 70d is pressed by the outer circumferential surface (upper part of FIG. 8) of the piston 22h of the relief valve 22, the movable contact 70c of the switch 70 moves to the identification contact 70b as shown in FIG. When the actuator 70d falls into the recess 22i formed on the outer peripheral surface of the piston 22h, the movable contact 70c of the switch 70 is switched to the fixed contact 70a side. The hydraulic pump 23 is operated.

With such a configuration, the relief valve 22 is connected to the liquid passage 2.
When the brake fluid pressure of No. 1 increases, the piston 22a moves to the right in FIG. 8 while compressing the relief spring 22f, and when the valve rod 22d comes into contact with the ball valve 22C, the ball valve 22C is moved by the valve loft 22d. It is separated from the valve seat, thereby the brake fluid in the liquid passage 21 is relieved to the reservoir 11, and abnormally high pressure is prevented from being generated in the liquid passage 21. Then, if the liquid pressure in the liquid passage 21 decreases, the piston 22a and the piston 2
2h integrally move to the left in FIG. 8, the actuator 70d of the switch 70, which had been pressed by the outer circumferential surface of the piston 22h, falls into the four parts 221 provided on the outer circumferential surface of the piston 22h, and is moved again. Hydraulic pump 23 is activated.

In addition, in this relief valve 22, the piston 22a is moved to the 8111th position by the relief spring 22f.
27 is biased to the left, the piston 22
a moves from side to side in accordance with fluctuations in the brake fluid pressure in the fluid passage 21, changing the volume of the fluid chamber 22ff in the case 22m, and also acts to relieve the impact pressure when the fluid pressure pump 23 is discharged.

Furthermore, in this relief valve 22, the direction in which the ball valve 22C is seated with respect to the valve seat is the same as the direction in which the brake fluid escapes when the valve is opened.
2C is inserted into the valve seat by both hydraulic pressure and valve spring 22b, and the sealing performance of this relief valve 22 is extremely good.

In addition, in the non-braking state of this embodiment, the liquid passage 21 and the valve chambers 18 and 19 in which the relief valve 22 is provided are
Brake fluid is constantly supplied to the fluid passage 20 that communicates between the two, and the brake fluid on which the fluid pressure equal to Eta of the relief spring 22f acts is constantly supplied.As will be described later, since the check valve 90 is closed, the fluid is not flowing in the valve chambers 18 and 19. The intake valves 31 and 32 to which the pressure has been applied move in the F direction as shown in Figure 2, and their tip portions 31a and 32a (see Figure 2, however, 32
(a not shown) project into the hydraulic pressure chamber 5.6. The set load of the relief spring 22f is set so that the brake fluid pressure when the ball valve 22c comes into contact with the valve rod 22d and is relieved is higher than the maximum fluid pressure generated in the fluid pressure chamber 5.6. has been done.

Check valve 90 is connected to valve chamber 18 and port 53 through fluid passages 56,54, respectively. This check valve 90 includes a piston 90a incorporating a valve spring 90b and a ball valve 90c, a spring 90d that biases the piston 90a against the hydraulic pressure acting on the liquid passage 56, and a spring 90d for opening the ball valve 90c. The valve rod 90e protrudes into the piston 90a. Then, when the brake fluid pressure in the fluid passage 56 increases and reaches a predetermined value, the piston 90a moves against the spring 9
The valve rod 90e presses the ball valve 90c and moves it away from the valve seat, causing the pressurized brake fluid in the fi passage 56 to flow into the fluid passage. 54 and the boat 53 to the boost hydraulic pressure chamber 88.

The set load of the spring 90d is set so that the brake fluid pressure when the ball valve opens under pressure from the valve rod 90e is higher than the set load of the relief spring 22r of the relief valve 22 by a predetermined amount (direction). is set to .

When the boost hydraulic pressure chamber 88 and brake hydraulic pressure are supplied, the second booster piston 83 moves to the left in the figure.
Since the first booster piston 82 fixed to the primary piston 3 is engaged with the second booster piston 83, the primary piston 3 also moves to the left as the second booster piston 83 moves. in this case,
If the acting area of the primary piston 3 is 8, the area of the annular pressure receiving step 83c of the second booster piston 83 is B, and the hydraulic pressure that the second booster piston 83 receives is Pa, then the liquid in the hydraulic pressure chamber 5 is The pressure pH is pH-xpA. That is, the hydraulic pressure P in the hydraulic pressure chamber 5 is the boost hydraulic pressure chamber 8.
It depends on the hydraulic pressure Pa applied to 8 and the pressure receiving area ratio B/A.

FIG. 2 is an enlarged sectional view showing the structure of the valve mechanism 26 assuming that no hydraulic pressure is acting on the liquid passage 20. A piston chamber G<b>1 is formed coaxially with the opening 16 of the valve chamber 18 to the hydraulic pressure chamber 5 . Inside this piston chamber 61, a piston 63 as a valve holding member equipped with a center hole 62 penetrating in the axial direction is slidable in a direction perpendicular to the inner peripheral surface 5a of the hydraulic pressure chamber 5 and has an opening. It is provided with a section 16 and a centering section. piston 63
A conical valve seat surface 63a is formed at the end of the center hole 62 (the end opposite to the opening 16). .

The intake valve 31 is a rod-shaped poppet valve that is slidably provided through the opening 16 of the housing 2 and the center hole 62 of the piston 63, and as the intake valve 31 moves, the tip end 3La opens into the hydraulic chamber 5. It is configured so that 7 appear. The intake valve 31 is connected to the piston 6.
The hemispherical valve portion 31b is seated on the valve seat surface 63a of No. 3.

Further, as shown in the cross-sectional views of FIGS. 3 and 4, the tip portion 31a and part of the shaft portion of the intake valve 31 are
The intake valve 31 has a substantially rectangular cross-sectional shape, and its four corners are slidably in contact with the inner circumferential surface of the opening 16 of the housing 2 and the inner circumferential surface of the center hole 62 of the piston 63 as support parts. This prevents twisting when the intake sleeve 33 pushes down the intake sleeve 33 to smooth its operation, and a liquid passage 64 is formed around the outer peripheral surface of the intake sleeve 31.

A spring holder 65 is integrally connected to the piston 63, and a check spring 66 is compressed between the spring holder 65 and the intake valve 31 to connect the valve portion 31b of the intake valve 31 to the piston 6.
It is seated on the valve seat surface 63a of No. 3 with a predetermined check pressure. Furthermore, the piston 63 is attached to the spring holder 6
5 and the wall surface of the valve chamber 18, the set spring 67 is biased in a direction away from the opening 16 side. The spring biasing force of the set spring 67 is made larger than that of the check spring 66,
At the position where the base end surface 31c of the intake valve 31 is in contact with the inner wall surface 60a of the plug 60, the piston 63 is maintained in the state shown in FIG. The spring biasing force of the set spring 67 also acts between the valve portions 31b of the valve 31.

In the case of this embodiment, in the non-braking state, the hydraulic pump 2
3 is not operating, but as mentioned above relief valve 2
The liquid passage 20 that communicates between the liquid passage 21 and the valve chambers 18 and 19 in which the relief spring 2
2. Brake fluid is supplied with hydraulic pressure equal to the weight of
Moreover, since the check valve 90 is closed, the valve chamber 18
, I9 is acted upon by a hydraulic pressure equivalent to the load of the relief spring 22f. As shown in FIG. 5, the end surface 63c of the piston 63 opposite to the end surface 63b
When hydraulic pressure is applied to the piston 63, the piston 63 moves toward the opening 16 against the biasing force of the set spring 67 while holding the intake valve 31 on the valve seat surface 63a due to the biasing force of the check spring 66. and its end face 63
b is in contact with the wall surface 61a of the piston chamber 61. Therefore, the intake valve 31 is in a state where its tip portion 31a protrudes into the opening 16.

During normal braking or anti-lock control, the valve mechanism 26 operates so that the stroke of the primary piston 3 reaches a predetermined point and the intake sleeve 33 closes the intake valve 3.
1, the valve mechanism maintains the state shown in FIG. 5, similar to the valve mechanism in the non-braking state.

Meanwhile, the primary piston 3 moves to the left in FIG.
When the stroke reaches a predetermined value, as shown in FIG. 6, the intake sleeve 33 engages with the tip 31a of the intake valve 31 and pushes down the intake valve 31 against the spring biasing force of the check spring 66. from,
The valve portion 31b separates from the valve seat surface 63a of the piston 63.

If the brake fluid pressure in the fluid passage 21 is high at that time, brake fluid is supplied into the fluid pressure chamber 5.

Here, the operation of Hydro Booster+4Attoo will be explained. As mentioned above, the set load of the spring 90d of the check valve 90 is set to be higher than the set load of the relief spring 22f of the relief valve 22 by a predetermined value. When the hydraulic pressure is maintained at atmospheric pressure, only the set load of the relief spring 22f acts on the liquid passage 56, and therefore the check valve 90 is in a closed state.

Next, when the brake pedal 37 is depressed, the pedal force is applied to the primary piston 3 via the rear axle piston 84, and the hydraulic pressure in the hydraulic pressure chamber 5.6 increases. therefore,
The hydraulic pressure in the piston chamber 22 of the relief valve 22 also increases, and the piston 22h moves to the left, so the switch 7.0
is turned on, the hydraulic pump 23 operates and the piston chamber 2
The piston 22h is pushed back to supply brake fluid to the piston 21. Accordingly, a hydraulic pressure higher than the hydraulic pressure in the hydraulic pressure chamber 6 by the set load of the relief spring 22f is applied to the liquid passage 56 communicating with the piston chamber 221 through the liquid passage 21, and the check valve 90 is opened. be excused.

Therefore, a high hydraulic pressure acts on the boost hydraulic pressure chamber 88, which is already isolated from the reservoir 11 by the booster valve 85, and the function as a hydro booster is achieved.

Next, regarding the operation of the brake fluid pressure control device shown in FIG.
This will be explained with reference to the figures.

Figure 9 shows changes in brake fluid pressure during normal braking and subsequent anti-lock control.
2 is a timing chart showing the opening and closing states of the Note that, in reality, the hydraulic pressures of the two brake systems are controlled independently, but for the sake of simplicity, the explanation here will be based on the assumption that both systems operate at the same time.

(A) ii During normal braking (Fig. 9 La=L+) As shown in Fig. 1, hold valve IIVI, 1 (V2 is 0F
F (open) and decay valves DVI and DV2 are 0FF (closed), by depressing the brake pedal 37, the primary piston 3 is pushed by the Pnoschrond 38 and moves to the left in FIG. The valve 35 closes, and the secondary piston 4 also moves to the left to close the center valve 36.
closes. Therefore, a hydraulic pressure is generated in the hydraulic chamber 5.6 which is increased by the hydrobooster Vial OO and is supplied to the wheel cylinder 8.9.13.14 for braking.

(B) During anti-lock control, due to an increase in the hydraulic pressure in the wheel cylinders 8.9.13.14, the system speed (the speed of the wheels to be controlled by each brake system, for example, both the front right wheel FR and the rear left wheel R1) When a predetermined deceleration of the wheel speed (speed determined by select low) is detected, a hold signal is generated from a control circuit (not shown) consisting of a microcomputer, and at this point 1. anti-lock control is started.

(1) Holding mode (Fig. 9 [, -・tz) At time t1 in Fig. 9, hold pulp l-+ V l and HV 2 are also turned on.
(closed) to block the fluid passage 7 to the wheel cylinder 8.9 and the fluid passage 12 to the wheel cylinder 13.14, so that the fluid pressure in the wheel cylinders 8.9.13, I4 is maintained. In this case, the valve mechanism 26.27 is in the state shown in FIG. 5, with the tip portions 31a, 32a of the intake valves 31.32 protruding into the hydraulic pressure chamber 5.6, respectively. At this time, when the intake sleeves 33, 34 are in a position where they can push down the intake valves 31, 32, the valve mechanisms 26, 27 are in the state shown in FIG.
3, high-pressure brake fluid flows into the hydraulic chamber 5.6 via the fluid passage 21.2o. This brake fluid pressure pushes the piston 3.4 back to the position where the intake sleeve 33.34 is disengaged from the intake valves 31, 32, and the fluid pressure in the fluid pressure chamber 5.6 is applied to the brake pedal. 37, the hydraulic pressure is proportional to the pedal force. In this case, the positions of the primary piston 3 and the secondary piston 4 cause the intake sleeve 33.34 to be connected to the intake valve 31.3.
2 is pushed down to communicate the hydraulic chamber 5.6 with the discharge port of the hydraulic pump 23, and the hydraulic pressure discharged from the hydraulic pump 23 causes the piston 3.4 to open the intake valve 31.32.
is pushed back until it closes the opening 16.17.

Therefore, even if a failure occurs in the hydraulic pressure source system,
Sufficient hydraulic pressure can be ensured within the hydraulic pressure chamber 5.6.

(2) Depressurization mode (Fig. 9 1 t-(s)) When the system speed further decreases, the decay valve DVI is activated from time t2.
, DV2 turns ON (open), and this causes the brake fluid in the wheel cylinder 8.9.13.14 to flow into the fluid passage 1O.
It flows into the reservoir 11 through 115 and is depressurized.

(3) Holding mode (Fig. 9 t, →ta) Due to the above brake fluid pressure reduction, at the time t when the system speed begins to recover after passing through a low peak, the decay valve DVI, DV27 becomes <0.
FF (closed) grins and goes into holding mode again.

(4) Pressure mode (Fig. 9 L a = t s) When the system speed reaches a high peak, the hold pulp HVI, HV
, 2 become 0FF (open), the piston 3.4 moves and the intake valve 31.32 opens, and the hydraulic pressure from the hydraulic pump 23 passes through the hydraulic chamber 5.6 to the wheel cylinder 8.
．． Given on 9.13.14. Time t4 in this figure 9
In the pressurized mode starting from the hold pulp HVI
, HV2 in small increments! , :0N-OFF causes the brake hydraulic pressure to rise stepwise.

(5) Holding mode (Fig. 9 t, -h i &) When the system speed starts to decrease due to the increase in brake fluid pressure, the holding mode is entered again, and hold pulp 1 (vl, HV2 is set to 0FF)
(closed), and at time 1h the decay valve DV1
．． ．． DV2 is turned ON (open) and the pressure reduction mode is entered again.

(Effects of the Invention) As is clear from the above explanation, the present invention eliminates the need for a large and expensive vacuum booster by employing a hydro booster that can provide the same boosting effect as a conventional vacuum booster. It is possible to do so. In particular, the combination of the inch-grate type master cylinder and the simple hydro booster device of the present invention enables compact and inexpensive brake fluid pressure generation! '4', device can be obtained. Furthermore, since the hydraulic power source of the hydrobooster device can be shared with the hydraulic power source of the inch-grade master cylinder, this combination is an extremely effective means.

In addition, in this embodiment, by employing the relief valve 22, a large-capacity accumulator is not required, and the discharge pressure of the hydraulic pump 23 is determined by the relief spring 22f, so that the brake from the hydraulic pump 23 is It is possible to absorb the impact pressure generated when discharging liquid, reduce the occurrence of operating noise, vibration, etc., and provide a small, lightweight, and inexpensive device. In addition, by adopting the 'ζ switch 70, the brake fluid pressure on the discharge side of the hydraulic pump 23 can be adjusted.
It is possible to monitor the absence of f and determine whether the hydraulic pump function is normal or not, and at the time of high deceleration due to normal braking, the intake sleeve 33 pushes down the intake valve 31 as shown in FIG. As a result, high-pressure brake fluid is supplied into the hydraulic chamber 5, which activates the switch 70 and drives the hydraulic pump 23, thereby preventing an increase in the pedal stroke and ensuring braking force even when the vapor is locked. can do.

Furthermore, since the ball valve 22c is configured to sit in the direction in which the brake fluid escapes when the valve is opened, the sealing performance is extremely good, and the piston 22a maintains a balanced hydraulic pressure due to the relief spring 22f. Therefore, during the relief operation, the hydraulic pressure in the liquid passage 21 does not decrease, and stable hydraulic pressure can be supplied.

Furthermore, in this embodiment, the normal intake valve 31.32
The hydraulic pressure acting on the seal is only that of the biasing force of the relief spring 22r, and no high hydraulic pressure is applied, improving the durability of the seal and the like.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a brake fluid pressure control device according to an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of its valve mechanism, and FIG.
Figure 4 shows the ■-m line and rV- line of the 2nd rM, respectively.
5 and 6 are longitudinal sectional views for explaining the operation of the valve mechanism shown in FIG. 2, and FIGS.
1 is an enlarged view of the main part of the apparatus shown in FIG. 1, and FIG. 9 is a timing chart for explaining anti-rotation/rotation control by the apparatus shown in FIG. 1-Master cylinder 3-Primary piston 4...Secondary piston 5.6-...Hydraulic pressure chamber 8.9.13.14-Wheel cylinder 11...Reservoir 18.19...Valve chamber 22-... Relief valve 23 - Hydraulic pump 31.32 - Intake valve 33.34 - Intake sleeve 35.36 - Center valve, 37 - Brake pedal 82 - First booster piston 83 - Second booster piston 84 - Reactor Piston 85 - Booster valve 90 - Check valve

Claims (1)

[Claims] A brake fluid pressure generating device for a vehicle, comprising a booster piston in a master cylinder that is operated by fluid pressure supplied from an auxiliary fluid pressure source to increase brake pedal depression force.