JP2649720B2 - Anti-lock control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an antilock control device for an automobile.

[Conventional technology]

The anti-lock control device performs a calculation based on a wheel speed sensor that detects a wheel speed, and a wheel speed signal from the wheel speed sensor, and detects whether the wheel has a tendency to lock or a tendency to recover from the lock, respectively. And an electronic control unit for issuing a hydraulic pressure change command such as pressure reduction or pressurization, and a hydraulic pressure control unit for controlling the hydraulic pressure applied to the wheel cylinders of the wheels from the master cylinder in accordance with the hydraulic pressure change command. I have.

When two front wheels are paired and two rear wheels are paired as a control method of these wheels, when either one of the pair of wheels is turned to the lock, both brake hydraulic pressures are set. To reduce the brake fluid pressure at the same time (select low), and only to reduce the brake fluid pressure at the same time when both wheels are locked (select high). On the other hand, there is a method of reducing the brake fluid pressure (independent).

Each control method controls the vehicle's directional stability, braking force,
Furthermore, since the steering characteristics are affected, the independent or select high control is generally applied to the front wheels, and the select low control is applied to the rear wheels.

On the other hand, in order to ensure safety in the event of a defect in the hydraulic circuit, in a vehicle employing X piping, the hydraulic pressure generation chamber of the master cylinder is separate for both rear wheels. Usually, separate hydraulic pressure control units are provided for the left and right wheels, respectively.

When these left and right hydraulic pressure control units are simultaneously controlled by the select row, the left and right brakes are affected by individual differences in the hydraulic pressure control units, for example, differences in the speed of pressure rise and fall due to differences in the solenoid response speed of control valves and hydraulic pipe diameters. There were problems such as imbalance in hydraulic pressure and insufficient braking force.

[Problem of the Invention]

In order to solve the above problems, the present inventor has proposed switching the rear wheel between select-row control and independent control as necessary (Japanese Patent Application Nos. 63-1333795 and 63-13795). No.-133796), increasing, maintaining, and reducing the brake fluid pressure
In the anti-lock control device that controls the state, when the select-low control is always performed, the solenoid control valves of both rear wheels are simultaneously driven, so that the solenoid drive circuit of the electronic control unit can be shared. Nevertheless, since independent control must also be performed, it is necessary to prepare drive circuits individually, which has the disadvantage of increasing costs.

Accordingly, an object of the present invention is to provide an anti-lock control device which can eliminate the shortage of the brake fluid pressure due to individual differences of the fluid pressure control unit and can reduce the cost by using a common drive circuit. It is.

[Solutions to solve the problem]

In order to solve the above problems, the first invention is disposed between a master cylinder and a wheel cylinder, and can control the flow of the brake fluid from the master cylinder to the wheel cylinder to two states of cutoff or communication by an electric signal. A first control valve, and a second control valve disposed between the wheel cylinder and the master cylinder, and capable of controlling the inflow of the brake fluid from the wheel cylinder to the master cylinder into two states of cutoff or communication by an electric signal. A hydraulic valve comprising a control valve for each wheel, and a pump disposed between the second control valve and the master cylinder and driven by an electric signal to pump up the brake fluid and to return to the master cylinder. An anti-lock control device comprising: a control unit; and an electronic control unit for providing an electric signal to the first and second control valves and a pump. A circuit for individually driving the first and second control valves associated with the respective wheels for the front wheels; and the first control valve associated with the respective wheels for the rear wheels. , And a circuit for collectively driving the second control valves associated with the respective wheels.

In the second invention, the electric wiring between the hydraulic control unit and the electronic control unit is provided. For the front wheels, the first and second control valves associated with the respective wheels and the electronic control unit are individually provided. For the rear wheels, wiring was separately performed between the first control valve and the electronic control unit associated with each wheel, and common wiring was formed between the second control valve and the electronic control unit. .

Further, the third invention is the first invention according to the first invention.
And a circuit for driving the second control valve is provided in the electronic control unit, so that the front wheel is individually combined with three states of pressurizing, holding, and depressurizing. In the case of pressurization, the other is held or pressurized, when one of the wheels is held, the other is held or pressurized, and when one of the wheels is depressurized, the other also controls the pressure control unit by combining the depressurized state It was done.

[Action]

As described above, for the rear wheels, the first control valves associated with the respective wheels are individually driven, and the second control valves are collectively driven. When the control valves are closed and the second control valves are collectively opened and the pump is driven, the brake fluid flows back to the master cylinder to be in a reduced pressure state. That is, the control of the select row in which the pressure of both wheels is reduced at the same time when one wheel is locked is achieved.

On the other hand, when the second control valve is closed at once,
Since the first control valves can be individually opened and closed, even if one wheel is in a pressure holding state, the other can be in a pressurized state. Therefore, when it is expected that the braking fluid pressure of one rear wheel is low, even if the other rear wheel is in the pressure holding state, one of the rear wheels can be in the pressurized state. There is no shortage.

〔Example〕

 FIG. 1 schematically shows an antilock control device.

Alternating voltage signal which is an output signal of the wheel speed sensors S ₁ to S _4, as shown, is converted into a pulse on the interface circuit, in the pulse processing circuit, a pulse count and calculation is performed in the central processing unit of the numerical value program operation, analysis, determination is made, based on the result, issues a command to the solenoid drive circuit and the motor relay drive circuit, for driving the solenoid SL ₁ to SL ₈ and the motor relay ML of the pressure control valve.

Here, the signal line from the central processing unit to the solenoid drive circuit is FR _{1 for} the solenoid SL ₁ of the first control valve of the right front wheel, and F ₁ for the solenoid SL ₂ of the second control valve.
R ₂ , F for solenoid SL ₃ of the first control valve for the left front wheel
L ₁ , FL _{2 for} the solenoid SL ₄ of the second control valve, RR _{1 for} the solenoid SL ₅ of the first control valve for the right rear wheel, R _{12 for} the solenoid SL ₆ of the second control valve, and R _{12 for} the solenoid SL ₆ of the second control valve. with respect to the solenoid SL ₇ of the first control valve RL _1, with respect to the solenoid SL ₈ of the second control valve has a R _12. Thus, the signal line R ₁₂ for controlling the second control valve SL ₆ and SL ₈ of the rear wheels are common, also, the wiring from the solenoid drive circuit to the hydraulic control unit is also common. In the figure, the interface circuit, the pulse processing circuit, the central processing unit, the solenoid drive circuit, and the motor relay drive circuit form an electronic control unit ECU.

Next, the rear wheel hydraulic control unit and its operation will be described with reference to FIG. 2 and FIG.

As shown, between the master cylinder MC and the rear wheel cylinder W _1, W _2, a first control valve 5 and 7 are arranged which are respectively driven by a solenoid SL ₅ and SL _7, the wheel cylinders the conduit for returning from W _1, W ₂ to the master cylinder MC, the second control valve 6 and 8 driven by a solenoid SL ₆ and SL ₈ is arranged. And
In the state shown in the figure, it is assumed that the solenoids SL ₅ , SL ₆ , SL ₇ , and SL ₈ are all demagnetized. At this time, the signal lines RR ₁ , R
The signals of L ₁ and R ₁₂ are all off.

As is clear from the figure, since the first control valves 5 and 7 are open and the second control valves 6 and 8 are closed, the master cylinder MC and the wheel cylinders W ₁ and W ₂ are in communication. Of the master cylinder MC
Brake pressure acts directly on the wheel cylinders W ₁ and W ₂ to bring both rear wheels into a pressurized state.

Next, from the above state, the only left rear wheel, when the pressure holding state, may output an ON signal from the signal line RL _1. Solenoid SL ₇ is excited accordingly, the first control valve 7 is closed, and since the second control valve 8 is also has orゝclosed, brake fluid pressure is trapped in the wheel cylinders W _2, the pressure holding Is done.

Similarly, only the right rear wheel, in order to obtain a state of the pressure holding may output an ON signal from the signal line RR _1.

To keep the pressure on both rear wheels, signal line RR ₁
And may such place an ON signal from the RL _1.

Further, to reduce the brake fluid pressure, the signal lines RR ₁ , R
An ON signal is issued from L ₁ and R ₁₂ and the motor M is driven by a motor relay drive circuit. Then, the solenoids SL ₅ , SL ₇ , SL ₆ and SL ₈ are excited, and the first control valves 5 and 7 are excited.
Is closed and the second control valves 6 and 8 are opened, so that the wheel cylinders W ₁ and W ₂ communicate with the reservoirs R ₁ and R ₂ , respectively.
By P _1, P _2, reservoir R _1, brake fluid that has been pumped out of R ₂ is recirculated to the master cylinder MC, brake hydraulic pressure is reduced.

As described above, for one of the rear wheels, if one wheel is in a pressurized state, the other is pressure holding or pressurizing. When the pressure of the wheel is reduced, the control is performed in combination with the state where the other wheel is also reduced.

For the front wheels, pressurization, pressure holding,
It is preferable to control by combining the three states of reduced pressure. In this case, the first and second control valves, pumps and motors for driving them as shown in FIG. 2 must be individually prepared for each wheel.

As shown in FIG. 2, the hydraulic pressure generation chamber of the master cylinder connected to the right rear wheel system is connected to the left front wheel system, and the hydraulic pressure generation chamber connected to the left rear wheel system is connected to the right front wheel system. X piping is being performed.

〔effect〕

According to the present invention, as described above, since the respective second control valves related to both rear wheels are controlled collectively, a common drive circuit can be used, thereby reducing costs. In addition, since the pressure reduction is simultaneously performed by the select low control for both rear wheels, the directional stability of the wheels can be maintained well.

On the other hand, the first control valves associated with the two rear wheels can be driven individually, so if it is expected that the brake fluid pressure of one rear wheel is low, Even when the pressure holding is practical, it is possible to pressurize without holding the pressure on one of the rear wheels. Can be prevented from becoming unduly low, resulting in insufficient braking force.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an antilock control device, FIG. 2 is a diagram showing details of a rear wheel hydraulic pressure control unit, and FIG. 3 shows correspondence between signals on a signal line and a pressure control state. It is a table. S _{1 to} S ₄ … Wheel speed sensor, FR ₁ , FR ₂ , FL ₁ , FL ₂ , RR ₁ , R ₁₂ , RL ₁ … Signal line, ML… Motor relay, SL _{1 to} SL ₈ … Solenoid , 5,7 ...... first control valve, 6,8 ...... second control valve, R _1, R ₂ ...... reservoir, P _1, P ₂ ...... pumps, MC ...... master cylinder, W _1, W ₂ …… wheel cylinder,

Claims (3)

(57) [Claims] A first control valve disposed between a master cylinder and a wheel cylinder, the first control valve being capable of controlling the flow of brake fluid from the master cylinder to the wheel cylinder into two states of shutting off or communicating by an electric signal; A second control valve disposed between the wheel cylinder and the master cylinder and capable of controlling the inflow of the brake fluid from the wheel cylinder to the master cylinder into two states of shutting off or communicating with each other by an electric signal, for each wheel; And a hydraulic pressure control unit comprising a pump disposed between the second control valve and the master cylinder and driven by an electric signal to pump up the brake fluid and return the brake fluid to the master cylinder; An antilock control device comprising an electronic control unit for providing an electrical signal to the control valve and the pump, wherein the electronic control unit is connected to a front wheel. A circuit for individually driving said first and second control valves associated with each wheel, and for a rear wheel, individually driving said first control valve associated with each wheel. And a circuit for collectively driving a second control valve associated with each wheel. 2. The electric wiring between the hydraulic control unit and the electronic control unit, and for the good neighbor, individual wiring between the first and second control valves associated with each wheel and the electronic control unit, respectively. The rear wheels are individually wired between the first control valve and the electronic control unit associated with each wheel, and common wiring is provided between the second control valve and the electronic control unit. The antilock control device according to claim 1. 3. A circuit for driving the first and second control valves is provided in an electronic control unit, so that the front wheel is individually combined with three states of pressurizing, holding, and depressurizing, and the rear wheel is combined with three states. For wheels, when one wheel is pressurized, the other is pressure holding or pressurizing, when one wheel is holding, the other is pressure holding or pressurizing, and when one is depressurizing, the other is also pressure reducing. 3. The anti-lock control device according to claim 1, wherein the hydraulic control unit is controlled by the control.