JP2002193092A - Vehicular brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular brake device causing little fluctuation in brake fluid pressure supplied by an auxiliary fluid pressure source. SOLUTION: This vehicular brake device has a hydraulic pump HB for boosting a brake fluid of a reservoir RS to prescribed pressure, an accumulator AC for storing the brake fluid boosted by a hydraulic pump HP as fluid pressure Pr, and a pressure sensor P for detecting the fluid pressure Pr of the accumulator AC, and is characterized by storing the fluid pressure in the accumulator AC by boosting the brake fluid by the hydraulic pump HP on the basis of a difference Pd between the fluid pressure Pr of the accumulator AC detected by the pressure sensor P and target fluid pressure Ptgt of the accumulator AC, and a pressure gradient ΔPr/Δt of the fluid pressure Pr of the accumulator AC detected by the pressure sensor P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake device mainly used for automatic braking of a vehicle.

[0002]

2. Description of the Related Art A conventional vehicle brake device is disclosed in Japanese Patent Application Laid-Open No. 2-136365. For this, the hydraulic pressure of the auxiliary hydraulic pressure source is controlled by a pressure switch connected to the pump motor operation circuit, and the pressure switch is closed by the lower limit of the hydraulic pressure of the auxiliary hydraulic pressure source, and is closed by the upper limit value. This is to open the pressure switch.

Japanese Patent Application Laid-Open No. 8-268256 discloses a vehicular brake device that controls a pump pressure in accordance with the sum of a brake control pressure based on a running state of a vehicle and a margin pressure based on brake control contents. ing.

[0004]

SUMMARY OF THE INVENTION In the vehicle brake device disclosed in the above-mentioned patent publication, variations in operation due to hysteresis or the like of a pressure switch are taken into consideration.
It is necessary to provide a predetermined pressure difference between the upper limit of the hydraulic pressure at which the pressure switch is opened and the lower limit of the hydraulic pressure at which the pressure switch is closed. The pressure fluctuates between an upper limit and a lower limit.

[0005] Further, in the vehicle brake device disclosed in the latter patent publication, it is conceivable that the amount of brake fluid supplied to the pump varies with respect to continuous brake operation.

Accordingly, an object of the present invention is to provide a vehicular brake device in which a variation in brake hydraulic pressure supplied by an auxiliary hydraulic pressure source is small in order to solve the above-mentioned problems.

[0007]

According to a first aspect of the present invention, a master piston is driven forward in response to an operation of a brake operating member to increase a brake fluid in a reservoir and to apply a brake fluid to a wheel cylinder. A master cylinder for outputting pressure, a hydraulic pump for increasing the brake fluid in the reservoir to a predetermined pressure, an accumulator for storing the brake fluid boosted by the hydraulic pump, and an accumulator connected to the accumulator. Pressurizing means for pressurizing the wheel cylinder with hydraulic pressure, accumulator hydraulic pressure detecting means for detecting the hydraulic pressure of the accumulator, hydraulic pressure of the accumulator detected by the accumulator hydraulic pressure detecting means, and target hydraulic pressure of the accumulator. Accumulator hydraulic pressure difference calculating means for calculating the difference between
An accumulator hydraulic pressure gradient calculating means for calculating a hydraulic pressure gradient of the accumulator hydraulic pressure detected by the accumulator hydraulic pressure detecting means; a hydraulic pressure of the accumulator calculated by the accumulator hydraulic pressure difference calculating means; and a target liquid of the accumulator. A hydraulic pressure for increasing the brake fluid by the hydraulic pump and storing the hydraulic pressure in the accumulator based on a difference between the hydraulic pressure and the hydraulic pressure gradient of the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure gradient calculating means. A vehicle brake device comprising control means.

According to the first aspect of the present invention, the difference between the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure difference calculating means and the target hydraulic pressure of the accumulator, and the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure gradient calculating means are calculated. Since the hydraulic pressure can be stored in the accumulator based on the hydraulic pressure gradient, fluctuations in the hydraulic pressure supplied by the accumulator can be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a vehicular brake device according to an embodiment of the present invention, and a master piston M is operated according to an operation of a brake pedal BP as a brake operation member.
The master cylinder MC which drives the P forward to increase the brake fluid in the reservoir RS and outputs the brake fluid pressure to the wheel cylinder WC, and the auxiliary fluid which boosts the brake fluid in the reservoir RS to a predetermined pressure and outputs the power fluid pressure The pressure source AS is connected to the auxiliary hydraulic pressure source AS and is also connected to the reservoir RS. The output power hydraulic pressure of the auxiliary hydraulic pressure source AS is adjusted to a predetermined pressure, and the master piston MP is adjusted by the adjusted hydraulic pressure. And a pressure regulating means RG corresponding to the pressure means of claim 1 to be driven. Further, a pressure-increasing valve IV, which is a linear valve in a normally closed state, is connected to the pressure-increasing-side hydraulic pressure path IP that connects the pressure-adjusting means RG to the auxiliary hydraulic pressure source AS. A pressure reducing valve DV which is a linear valve in a normally open state is interposed in the pressure path DP. The pressure increasing valve IV and the pressure reducing valve DV are electrically connected to a control means CT corresponding to the accumulator hydraulic pressure difference calculating means, the accumulator hydraulic pressure gradient calculating means and the power hydraulic pressure controlling means, respectively. As a result, the control means CT sets the pressure increasing valve IV
In addition, the energization of the pressure reducing valve DV is controlled, the pressure-increasing-side hydraulic pressure path IP and the pressure-reducing-side hydraulic pressure path DP are controlled to open and close, and the hydraulic pressure of the pressure adjusting means RG is controlled to a predetermined pressure equal to or higher than the atmospheric pressure. Control means C
T includes an accumulator hydraulic pressure difference calculating means DC, an accumulator hydraulic pressure gradient calculating means GC, and a hydraulic control means PT.

The auxiliary hydraulic pressure source AS is shown in detail in FIG. 7, and will be described in detail with reference to FIG. Auxiliary hydraulic pressure source AS
Is provided with a hydraulic pump HP driven by the electric motor M, the input side of which is connected to the reservoir RS, the output side of which is connected to the accumulator AC via the check valve C1, and the hydraulic pressure assisting section HB described later. It is connected to the input port 1f and is connected to the hydraulic pressure assisting unit HB input port 1e via the pressure increasing valve IV. The accumulator AC is connected to a pressure sensor P corresponding to the accumulator hydraulic pressure detecting means so that the auxiliary hydraulic pressure source AS is maintained at a predetermined output hydraulic pressure. It is configured to monitor.

Returning to FIG. 1, the description will be continued. The inter-vehicle distance sensor VD mounted on the vehicle detects the inter-vehicle distance with the preceding vehicle and transmits a detection signal to the control means CT. Further, the pressure sensor P as the auxiliary hydraulic pressure detecting means detects the hydraulic pressure of the auxiliary hydraulic pressure source AS and transmits a detection signal to the control means CT. Further, the wheel speed sensor WS detects the rotation speed of the wheel and transmits a detection signal to the control means CT. The brake switch BS detects the operation of the brake pedal BP and sends a detection signal to the control means CT.

The control means CT is configured as shown in FIG. 2, for example, and is connected to each of the above-described sensors to control the energization and non-energization of the pressure increasing valve IV and the pressure reducing valve DV. The electric motor M, which will be described later, constituting the auxiliary hydraulic pressure source AS is also controlled by the control means CT.
, And thereby the drive is controlled. In FIG. 2, the control means CT includes CPs connected to each other via a bus.
A microcomputer CM comprising U, ROM, RAM, an input interface IT, and an output interface OT is provided. Each output signal of the brake switch BS, the pressure sensor P, the inter-vehicle distance sensor VD, and the wheel speed sensor WS is configured to be input to the CPU from the input interface IT via the amplifier circuit AI. Further, control signals are output from the output interface OT to the drive motor M, the pressure increasing valve IV, and the pressure reducing valve DV via the drive circuit AO, respectively. In the microcomputer CM, the ROM corresponds to the flowchart shown in FIG. The CPU executes the program while an ignition switch (not shown) is closed, and the RAM temporarily stores variable data necessary for executing the program.

In the hydraulic brake system constructed as described above, the control means CT controls the pressure increasing valve IV and the pressure reducing valve D.
When a series of processes for controlling the V and a process for making the power hydraulic pressure output from the auxiliary hydraulic pressure source AS constant are performed, and an ignition switch (not shown) is closed, a predetermined value is set in the microcomputer CM. The execution of the program starts. Hereinafter, the control of the pressure increasing valve IV and the pressure reducing valve DV and the compensation control of the power hydraulic pressure of the auxiliary hydraulic pressure source AS will be described with reference to the flowchart of FIG.

In FIG. 3, first, at step 101, the microcomputer CM is initialized and various operation values are cleared. Next, the routine proceeds to step 102, where output signals from the brake switch BS, the pressure sensor P, the following distance sensor VD, the wheel speed sensor WS, and the like are read. Subsequently, in step 103, the state of the brake switch BS is determined, and when the brake pedal BP is operated and the brake switch BS is turned on, the process proceeds to step 104, in which conditions for starting energization of the pressure increasing valve IV and the pressure reducing valve DV are started. ,
For example, based on an inter-vehicle distance to a preceding vehicle detected by the inter-vehicle distance sensor VD and the own vehicle speed calculated from the wheel speed detected by the wheel speed sensor WS, an automatic braking force for generating a braking force regardless of the brake operation of the vehicle. It is determined whether or not the condition that it is necessary to perform the brake control and avoid the danger of collision with the vehicle ahead is satisfied. If it is determined that the condition for performing the automatic brake control is satisfied, the process proceeds to step 105.

In step 105, the booster valves IV,
Control of the pressure-reducing valve DV is started, and the pressure-increasing-side hydraulic pressure path IP and the pressure-reducing-side hydraulic pressure path DP are controlled to open and close. And step 1
Proceeding to 06, it is determined from the detection value of the pressure sensor P whether or not the condition for compensating the hydraulic pressure in the accumulator AC is satisfied. This determination will be described with reference to FIG. The hydraulic pressure of the accumulator AC is detected by the pressure sensor P, and the accumulator hydraulic pressure difference calculating means DC and the accumulator hydraulic pressure gradient calculating means GC each detect the power hydraulic pressure detection value P of the accumulator AC by the pressure sensor P.
Based on r and the target accumulator hydraulic pressure value Ptgt, an accumulator hydraulic pressure difference: Pd = Ptgt−Pr, and an accumulator hydraulic pressure gradient (time differential value of hydraulic pressure detection value Pr = (P1−P0) / (t1−t0)) : P1 is time t1
, P0 is the hydraulic pressure at time t0): ΔPr / Δt is calculated. The control means CT uses the hydraulic pump drive control map shown in FIG. 4 to calculate the accumulator hydraulic pressure difference: P
From d and the accumulator hydraulic pressure gradient: ΔPr / Δt, it is determined whether it is necessary to drive the hydraulic pump HP to compensate the hydraulic pressure in the accumulator AC. In FIG. 4, if the states of the accumulator hydraulic pressure difference: Pd and the accumulator hydraulic pressure gradient: ΔPr / Δt are located on the right side with respect to the center diagram, it is determined that the compensation condition of the accumulator AC is satisfied. Accumulator fluid pressure difference: P
If the state of d and the accumulator hydraulic pressure gradient: ΔPr / Δt is located on the left side of the center diagram, it is determined that the compensation condition of the accumulator AC is not satisfied.

In step 106, accumulator A
If it is determined that the compensation condition of C is satisfied, the routine proceeds to step 107, where the hydraulic pressure control means PT drives the electric motor M to operate the hydraulic pump HP, and the accumulator A
Refill C with hydraulic pressure. At this time, the hydraulic pressure control means PT energizes the electric motor M for operating the hydraulic pump HP in accordance with the accumulator hydraulic pressure gradient: ΔPr / Δt based on the hydraulic pump drive control diagram shown in FIG. The duty ratio of the drive current to be performed is determined. Based on the hydraulic pump drive control diagram of FIG. 5, the accumulator hydraulic pressure gradient: ΔPr / Δt
Is large, the duty ratio of the drive current supplied to the electric motor M is increased, and control is performed so that the discharge amount from the hydraulic pump HP increases. Further, the present invention is not limited to this, and a hydraulic pressure sensor (not shown) may be provided at the discharge port of the hydraulic pump HP to control the hydraulic pressure discharged from the hydraulic pump.

As described above, in the present embodiment, not only the accumulator hydraulic pressure difference: Pd but also the accumulator hydraulic pressure difference: Pd and the accumulator hydraulic pressure gradient: ΔPr / Δ
Since the drive control of the hydraulic pump HP is performed based on t, the relationship between the hydraulic pressure of the accumulator AC and the operating state of the hydraulic pump HP is as shown in FIG. In FIG. 6, the upper two curves show the hydraulic pressure diagram of the accumulator AC, and the two lower time charts show the operating state of the hydraulic pump HP. Further, in FIG. 6, reference numeral 1 denotes a case where the accumulator hydraulic pressure gradient: ΔPr / Δt is large in both the hydraulic pressure diagram and the time chart, and 2 denotes an accumulator hydraulic pressure gradient: ΔPr / Δt in both the hydraulic pressure diagram and the time chart. Represents things when they are small. As can be seen from FIG. 6, when the accumulator hydraulic pressure gradient: ΔPr / Δt is large, the operation of the hydraulic pump HP is performed early.

Next, the routine proceeds to step 108, where it is determined whether or not the condition for completing the compensation of the hydraulic pressure of the accumulator AC is satisfied. In step 108, it is determined whether or not the detected value of the fluid pressure of the accumulator AC by the pressure sensor P has reached the target accumulator fluid pressure value Ptgt, and the detected value of the fluid pressure of the accumulator AC is set to the target accumulator fluid pressure value. If it is determined that Ptgt has been reached, the process proceeds to step 109, and if it is determined that the detected value of the hydraulic pressure of the accumulator AC has not yet reached the target accumulator hydraulic pressure value Ptgt, the process returns to step 107 and returns to the accumulator AC. The hydraulic pressure compensation control is continued.

At step 109, the pressure increasing valve IV,
It is determined whether a condition for ending the control of the pressure reducing valve DV is satisfied. For example, when the speed of the own vehicle is sufficiently reduced by the automatic brake control and the danger of a collision with the vehicle in front is avoided, it is determined that the automatic brake control ends. If it is determined that the automatic brake control has been completed, the routine proceeds to step 110, where the energization of the pressure increasing valve IV and the pressure reducing valve DV is terminated.

In the pressure increasing / reducing valve control in step 105, first, the regulator pressure RP is set from the required wheel brake fluid pressure. Specifically, the required vehicle deceleration is calculated from the inter-vehicle distance to the preceding vehicle detected by the inter-vehicle distance sensor VD and the own vehicle speed calculated from the wheel speed detected by the wheel speed sensor WS. Based on the obtained vehicle deceleration, the hydraulic pressure of the wheel cylinder WC, that is, the hydraulic pressure PMC required by the master cylinder MC is calculated from the specifications of the wheel brake. here,
Between the hydraulic pressure PMC of the master cylinder MC and the hydraulic pressure PRG introduced from the auxiliary hydraulic pressure source AS to the pressure adjusting means RG, PM
Since there is a relation of C = α · PRG (α is a constant), the hydraulic pressure PRG to be introduced from the auxiliary hydraulic pressure source AS to the pressure adjusting means RG
Is PRG = PMC / α. Therefore, the required hydraulic pressure PM of the master cylinder MC is reduced to the auxiliary hydraulic pressure source AS.
The hydraulic pressure PRG to be introduced into the pressure adjusting means RG is determined from the above. The current to be supplied to the pressure increasing valve IV and the pressure reducing valve DV is determined according to the hydraulic pressure PRG to be introduced to the pressure adjusting means RG.

FIGS. 7, 8 and 9 show the structure of a hydraulic brake device constituting a vehicle brake device according to an embodiment of the present invention, in which a pedaling force applied to a brake pedal BP is applied to an input rod 3. Through the hydraulic pressure assisting portion HB (the pressure adjusting means R in FIG. 1).
G), brake fluid pressure is output from master cylinder MC, and when it is determined that automatic braking control is required in the vehicle, brake pedal B
Regardless of the operation of P, the brake fluid pressure regulated by the fluid pressure assisting unit HB is output from the master cylinder MC,
It is configured to be supplied to a wheel cylinder WC mounted on each wheel of the vehicle. FIG. 7 shows the entire configuration, and FIGS. 8 and 9 show the initial position (at rest) and operation of the hydraulic pressure assisting section HB in an enlarged manner, respectively, but the control means CT of FIG. 1 is omitted. are doing.

Master cylinder MC according to the present embodiment
As shown in FIG. 7, a cylinder bore 1a and a larger cylinder bore 1b are formed in a housing 1, and a master piston 10 (corresponding to the master piston MP in FIG. 1) and a power piston 5 are accommodated in series. Have been.
The housing 1 is formed with liquid supply ports 1i, 1j and output ports 1k, 1n. The output port 1k communicates with a first pressure chamber R1 described later, and the output port 1n communicates with a second pressure chamber described later. It communicates with R2. Output port 1
k is connected to a wheel cylinder (not shown) of the front wheel of the vehicle, and the output port 1n is connected to a wheel cylinder (not shown) of the rear wheel of the vehicle.

A cup-shaped seal member S1, S2 is disposed at the front in the housing 1, and a master piston 10 having a bottomed cylinder is slidably slidable through these seal members S1, S2. The first pressure chamber R <b> 1 is supported and formed in front of the master piston 10. A power piston 5 is provided in the housing 1 behind the master piston 10.
Are housed in the rear opening 1c of the housing 1 so as to be slidable in a liquid-tight manner. A second pressure chamber R2 is defined between the master piston 10 and the power piston 5.

As shown in FIG. 7, a spring 11 is stretched between the front end surface in the housing 1 and the bottom surface of the concave portion of the master piston 10, and the master piston 10 is urged rearward. Further, a locking portion 10f is formed in which the master piston 10 is bent rearward. The locking portion 10f is locked to a step in the housing 1, and the rear end position of the master piston 10 is regulated. And master piston 1
The first pressure chamber R1 is configured to communicate with the reservoir RS via the communication hole 10e and the liquid supply port 1i formed in the skirt portion at the rear end position of the non-operating state at 0.

On the other hand, as shown in FIG. 2, lands 5x and 5y are formed on the front and rear of the power piston 5, and seal members S3 and S5 are fitted to the lands 5x and 5y, respectively. A seal member S4 is disposed on the inner peripheral surface of the housing 1 between them,
Further, a cup-shaped sealing member S
6, inner peripheral surface of housing 1 between S7 and power piston 5
An annular chamber R6 is formed between the annular chamber R6 and the outer peripheral surface. In order to actually arrange the seal members S1 to S7 as shown in FIGS. 7 and 8, it is necessary to configure the housing 1 by combining a plurality of cylinders and divide the power piston 5 into two parts. However, since it is a design matter, it will be described as one component.

Thus, the seal member S2 and the seal member S
3, between the second pressure chamber R2, the annular member R3 between the seal member S3 and the seal member S4, the annular chamber R4 between the seal member S4 and the seal member S5, and between the seal member S5 and the seal member S6. A power chamber R5 is formed. The power piston 5 is formed with a concave portion 5a at the front, and a stepped hollow portion 5b is formed following the concave portion 5a. Hole 5f, communication hole 5g, 5 communicating with power chamber R5
h, and a communication hole 5d communicating with the annular chamber R6 is further formed.

The input member 4 is accommodated behind the hollow portion 5b via a seal member S8 so as to be slidable in a liquid-tight manner, and the input rod 3 is connected to the rear thereof. A communication hole 4c is formed in the input member 4 in the axial direction, and a communication hole 4d in the radial direction is formed to communicate with the communication hole. The annular hole 4e, the communication hole 5d of the power piston 5, and the annular chamber R6 are formed. Through the drain port 1d. In front of the input member 4 in the hollow portion 5b, a spool 6 is accommodated slidably in a liquid-tight manner via a seal member S9, and further in front of the input member 4, a plunger 7 is slidably accommodated. In the recess 5a, a reaction force rubber disk 8 is disposed as a reaction force transmission elastic member, and a pressure receiving member 9 is housed in front of the reaction force rubber disk 8 in close contact with the reaction force rubber disk 8 so as to be movable back and forth. A spring 12 is interposed between the pressure receiving member 9 and the master piston 10 so that a direct force can be transmitted therebetween.
In the non-operation shown in FIGS. 7 and 8, a slight gap is formed between the reaction rubber disc 8 and the end face of the plunger 7.

As shown in an enlarged view in FIG. 8, a communication hole 6c is formed in the spool 6 in the axial direction, and a step 6e is formed on the outer peripheral surface.
Are formed on the outer periphery of the small diameter portion.
6 g are formed. Further, a communication hole 6h is formed in the radial direction, through which the communication hole 6c communicates with the annular groove 6g. 8, the spool 6 has the annular grooves 6f and 6g facing the openings of the communication holes 5g and 5h, respectively, and the power chamber R5 has the communication hole 5h, the annular groove 6g and the communication hole 6h as shown in FIG. Through the communication hole 6c. When the spool 6 moves forward, the communication between the power chamber R5 and the communication hole 6c is cut off, and the annular groove 6f is connected to the communication hole 5f and the communication hole 5c.
The power chamber R5 communicates with the input port 1f in opposition to the opening g. Step 6 of spool 6 in power piston 5
A hydraulic pressure introduction chamber R7 is formed behind e, so that the output hydraulic pressure of the auxiliary hydraulic pressure source AS is supplied to the hydraulic pressure introduction chamber R7 through the communication hole 5e during automatic braking. . Note that a liquid chamber communicating with the reservoir RS is formed between the rear end of the spool 6 and the input member 4, and this liquid chamber is separated from the liquid pressure introduction chamber R7.

On the other hand, the plunger 7 has an annular groove 7g formed on the outer peripheral surface at the rear thereof, and an axial hole 7e which opens at the rear and faces the opening of the communication hole 6c of the spool 6, and is formed. Annular groove 7 through radial communication hole 7f
g. Thus, the space in which the plunger 7 is accommodated is the communication hole 6 c of the spool 6 and the communication hole 4 of the input member 4.
c, 4d, annular groove 4e, communication hole 5 for power piston 5
d and the drain port 1d via the annular chamber R6.

An input port 1 is located behind the housing 1.
e, 1f and a drain port 1d are formed, the drain port 1d is connected to a reservoir RS, and the input ports 1e, 1f are connected to an auxiliary hydraulic pressure source AS. The input port 1e opens to the annular chamber R3, and is connected to the auxiliary hydraulic pressure source AS via a normally-closed pressure-intensifying valve IV and to the reservoir RS via a normally-open pressure-reducing valve DV. These pressure increasing valve IV and pressure reducing valve DV are constituted by linear solenoid valves.

Further, in the present embodiment, a flow passage 1g for communicating the second pressure chamber R2 and the power chamber R5 is formed in the housing 1, and the normally open differential pressure reaction reverse flow is formed in the flow passage 1g. A stop valve CV (hereinafter simply referred to as a check valve CV) is provided. That is, the communication chamber is always maintained in a communication state, and is opened according to the pressure difference between the power chamber R5 and the second pressure chamber R2. The power chamber R5 is larger than the pressure in the second pressure chamber R2 and the pressure difference is a predetermined value. When it is above, the check valve CV is closed,
Both are 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 CV is in the open position.
By evacuating from the fifth side, the brake fluid from the reservoir RS can be introduced through the fluid supply port 1j, and the air in the second pressure chamber R2 can be easily and surely vented.

Next, the operation of the hydraulic brake device configured as described above will be described. First, when the brake pedal 2 is in a non-operating state, each component is in a state shown in FIGS. The closed position and the pressure reducing valve DV are in the open position, and the hydraulic pressure assisting unit HB is in a non-operating state. At this time, the annular chamber R4 stores the accumulator AC of the auxiliary hydraulic pressure source AS.
The communication hole 5 f is closed by the spool 6. The power chamber R5 is provided with a communication hole 5
h, a groove 6g of the spool 6 opposed thereto, a communication hole 6h and a communication hole 6c, and communication holes 4c and 4d of the input member 4 annular grooves 4.
e, communicating with the reservoir RS via the communication hole 5d of the power piston 5, the annular chamber R6, and the drain port 1d. Further, the power chamber R5 communicates with the second pressure chamber R2 via the flow path 1g and the check valve CV. Thus, even when the assisting hydraulic pressure source AS is driven, only the rearward pressing force is applied to the power piston 5 by the hydraulic pressure of the annular chamber R4. Will be maintained.

When the automatic brake is started while the brake pedal BP (omitted in FIGS. 8 and 9) is not operated, the pressure increasing valve IV is opened and the pressure reducing valve DV is closed as shown in FIG. The auxiliary hydraulic pressure source AS is driven, and the initial position of each component immediately after the start is the same as in FIG.
That is, since the spool 6 and the plunger 7 are at the same position as in FIG. 8, the communication hole 5f is blocked by the spool 6, but the hydraulic pressure behind the step 6e of the spool 6 from the input port 1e via the communication hole 5e. Since the output hydraulic pressure of the auxiliary hydraulic pressure source AS is applied to the introduction chamber R7, the spool 6 is driven forward to be in the state shown in FIG. Thus, the power room R5 has the communication hole 5
g, which communicates with the auxiliary hydraulic pressure source AS via the annular groove 6f, the communication hole 5f, and the input port 1f opposed thereto, so that the power piston 5 is driven forward and the master piston 10 is driven forward, and each wheel is driven. The brake fluid pressure is supplied to a wheel cylinder (not shown) of the vehicle.

The present invention is not limited to the above embodiment. For example, the pressure adjusting means RG is not an essential component of the present invention, and the present invention is applied to a traction control system, a stability control system, or the like, which supplies the hydraulic pressure of an accumulator directly to a wheel cylinder via an electromagnetic valve. It is possible to

The automatic brake system is not an essential component, and can be applied to a normal brake system.

Further, the pressure-increasing valve and the pressure-reducing valve in the present embodiment do not necessarily have to be linear valves, and various changes can be made.

[0037]

According to the present invention, the hydraulic pump is operated to store the hydraulic pressure in the accumulator based on the difference between the hydraulic pressure of the accumulator and the target hydraulic pressure of the accumulator and the hydraulic pressure gradient of the hydraulic pressure of the accumulator. Therefore, it is possible to provide a vehicular brake device in which the fluid pressure of the accumulator is small.

[Brief description of the drawings]

FIG. 1 is an overall view showing a vehicle brake device of the present invention.

FIG. 2 is a diagram showing control means of the vehicle brake device of the present invention.

FIG. 3 is a view showing a flowchart of control means of the vehicle brake device of the present invention.

FIG. 4 is a diagram showing a hydraulic pump drive control map of the vehicle brake device of the present invention.

FIG. 5 is a diagram showing a hydraulic pump drive control diagram of the vehicle brake device of the present invention.

FIG. 6 is a diagram showing a power hydraulic pressure of an accumulator and an operation time chart of a hydraulic pump of the vehicle brake device of the present invention.

FIG. 7 is an overall view showing a structure of a hydraulic brake device of the vehicle brake device of the present invention.

FIG. 8 is a partially enlarged view showing a structure of a hydraulic pressure assisting portion of the vehicle brake device of the present invention.

FIG. 9 is a partially enlarged view showing an operation state of a hydraulic assisting portion of the vehicle brake device of the present invention.

[Explanation of symbols]

BP: Brake operating member MP, 10: Master piston RS: Reservoir WC: Wheel cylinder MC: Master cylinder P: Pressure sensor HP: Hydraulic pump HP AC: Accumulator RG: Pressure adjusting means HB: Hydraulic pressure assisting unit CT: Control means DC: Accumulator hydraulic pressure difference calculating means GC: Accumulator hydraulic pressure gradient calculating means PT: Hydraulic pressure controlling means Pr ... Hydraulic pressure of accumulator AC Ptgt ... Target hydraulic pressure of accumulator AC Pd ... Difference between hydraulic pressure Pr of accumulator AC and target hydraulic pressure Ptgt of accumulator AC ΔPr / Δt: Hydraulic pressure of accumulator AC Pr pressure gradient

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaki Oishi 2-1-1 Asahi-cho, Kariya-shi, Aichi F-term (reference) in Aisin Seiki Co., Ltd. 3D046 BB18 CC02 HH02 HH16 HH20 HH23 HH36 LL11 LL23 LL37 LL41 3D048 BB33 BB35 CC08 HH15 HH16 HH26 HH66 RR01 RR06 RR35 3D049 CC02 HH12 HH13 HH20 HH42 HH47 RR01 RR04 RR13

Claims (3)

[Claims] 1. A master cylinder for driving a master piston forward in response to an operation of a brake operating member to increase brake fluid in a reservoir and output brake fluid pressure to a wheel cylinder, and the brake fluid in the reservoir to a predetermined pressure. A hydraulic pump for increasing the pressure, an accumulator for storing the brake fluid pressurized by the hydraulic pump, pressurizing means connected to the accumulator to pressurize the wheel cylinder by the hydraulic pressure of the accumulator, and a hydraulic pressure of the accumulator. Accumulator hydraulic pressure detecting means for detecting the accumulator hydraulic pressure, accumulator hydraulic pressure difference calculating means for calculating a difference between the accumulator hydraulic pressure detected by the accumulator hydraulic pressure detecting means and the accumulator target hydraulic pressure, and the accumulator hydraulic pressure detecting means Hydraulic pressure of the accumulator detected by An accumulator hydraulic pressure gradient calculating means for calculating a gradient, a difference between the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure difference calculating means and a target hydraulic pressure of the accumulator, and an accumulator hydraulic pressure gradient calculating means. A vehicle brake device comprising: hydraulic control means for increasing the brake fluid by the hydraulic pump based on a hydraulic pressure gradient of the accumulator and storing the hydraulic pressure in the accumulator. 2. The hydraulic pressure control means controls the discharge amount of the hydraulic pump based on a hydraulic pressure gradient of the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure gradient calculating means. A vehicle brake device that satisfies the claim 1. 3. The hydraulic pressure control means controls the discharge hydraulic pressure of the hydraulic pump based on the hydraulic pressure gradient of the accumulator hydraulic pressure calculated by the accumulator hydraulic pressure gradient calculating means. A vehicle brake device that satisfies the following claim 1.