KR100379923B1 - Anti-lock brake system for vehicle - Google Patents

Abstract

PURPOSE: An anti-lock brake system for a vehicle is provided to reduce the cost and perform precise automatic braking by driver's will by forcibly pumping oil stored in an oil storage tank through an SR motor and a suction pump and forming braking hydraulic pressure, in operating a brake pedal. CONSTITUTION: An anti-lock brake system for a vehicle comprises a pedal sensor(20) sensing operation of a brake pedal(10), and an SR(Switch Reluctance) motor(40) and suction pumps(41), installed to a hydraulic pressure line connecting oil storage tank(33) with brakes(80,81,82,83). If the brake pedal is pressed, the SR motor and the suction pumps are operated and oil in the oil storage tank is transmitted to the brakes by pumping force of the suction pumps and thus, braking force is generated. Accordingly, the cost of the brake system not requiring an energizing unit is reduced. Precise braking control by driver's will is performed through operation of the SR motor and the suction pumps electrically operated. Normal close-type solenoid valves(31) are disposed to a hydraulic pressure line(32) connecting an emergency master cylinder(30) and normal open-type solenoid valves(60), and pedal simulators(35) with normal open-type solenoid valves(34) are disposed to the inlet side of the normal close-type solenoid valve. Accordingly, braking hydraulic pressure generated from the emergency master cylinder flows into the pedal simulators and thus a driver feels braking action. If the SR motor and the suction pump are not operated, the braking hydraulic pressure is directly transmitted to the brakes, for braking action.

Description

Automotive Antilock Brake System

The present invention relates to a vehicle anti-lock brake system, and more particularly, to a brake system that performs deceleration or stop operation of a vehicle through an SR motor, a suction pump, and an electric control device for controlling the same without using a booster. will be.

Vehicles are equipped with a brake system for braking. Recently, various kinds of systems have been proposed for obtaining a stronger and more stable braking force. Among them, the anti-lock brake system exhibits the most advanced effect. FIG. 1 is a schematic diagram showing a general configuration of such an anti-lock brake system.

Conventional anti-lock brake system is a drum or caliper hydraulic brake (9a, 9b, 9c, 9d) to generate a braking force by hydraulic pressure to the front wheel (FR, FL) and the rear wheel (RR, RL), respectively, as shown here Is installed, and is composed of a large power unit 2 and the master cylinder (3) for forming and transmitting hydraulic pressure to the brake (9a, 9b, 9c, 9d).

The power booster 2 is a device that generates a large braking force with a small force by using a pressure difference between the vacuum and the atmosphere, and is operated by being connected to the brake pedal 1 provided in the driver's seat. The master cylinder 3 forms hydraulic pressure by receiving the amplified force from the power booster 2 and is connected to the brakes 9a, 9b, 9c, and 9d via hydraulic lines.

On the other hand, solenoid valves 5 and 6 are provided at the inlet and outlet sides of each of the brakes 9a, 9b, 9c and 9d to control the hydraulic pressure transmitted to the brakes 9a, 9b, 9c and 9d. Normally open solenoid valves (5, hereinafter referred to as NO solenoid valves) are arranged on the side, and normally closed solenoid valves (6, hereinafter referred to as NC solenoid valves) are installed on the outlet side. These solenoid valves 5 and 6 are controlled by an electric controller not shown, thereby exhibiting a strong and stable braking force.

A low pressure accumulator 8a is provided downstream of the NC solenoid valve 6 to temporarily store oil discharged from the brakes 9a, 9b, 9c, and 9d. In addition, a high pressure accumulator 8b is installed at the rear of the low pressure accumulator 8a, and a pump 7a is installed between them to pressurize the low pressure oil in the low pressure accumulator 8a. It is configured to pump to the radar 8b. Reference numeral 7 denotes a motor for driving the pump 7a.

In the conventional anti-lock brake system configured as described above, when the driver presses the brake pedal 1 while driving, power is generated by the pressure difference in the power supply device 2, and the master cylinder 3 receives the amplified force. To form hydraulic pressure. The hydraulic pressure is transmitted to the respective brakes 9a, 9b, 9c, and 9d provided in the front wheels FR and FL and the rear wheels RR and RL through the NO-type solenoid valve 5 to brake.

On the other hand, when excessive braking pressure is transmitted than the road condition, a kind of slip phenomenon occurs that the tire of the vehicle stops rotating and slips, and this phenomenon is detected by a wheel sensor (not shown) mounted on the wheel of the vehicle and antilock brake To the electrical control device (not shown) of the system. Accordingly, in the electric control apparatus, the NC type solenoid valve 6 is operated to open to remove the oil in the brakes 9a, 9b, 9c, and 9d, thereby lowering the braking pressure. The oil discharged through the NC-type solenoid valve 6 is moved to the low pressure accumulator 8a and stored for a while, and as the motor 7 is driven, the pressure is increased again through the pump 7a, thereby increasing the pressure. It is circulated to the master cylinder 3 or the NO type solenoid valve 5 in the state where the abrupt pressure waveform was reduced past the radar 8b and the orifice 8c.

However, such a conventional anti-lock brake system takes up a large number of parts such as a booster device (2) and a master cylinder (3) for forming a boost force using a pressure difference, and converts it into a hydraulic pressure. Repair is not easy.

In addition, even if the driver presses the brake pedal 1 with much greater force than the normal state, the power booster 2 amplifies all of them so that more rigidity is required to prevent breakage than the pressure required for braking. In addition, there is a problem in that the output of the motor 7 should be used because the anti-lock brake system should operate without abnormality even when generating a braking force that is much larger than the normal state.

The present invention is to solve this problem, the main object of the present invention by configuring the SR motor and the suction pump in the hydraulic line connecting the pedal sensor, the oil storage tank and the brake to detect the operation of the brake pedal, brake pedal When stepping on, the oil in the oil storage tank is driven hydraulically to the brakes of each wheel by the operation of the SR motor and the suction pump to provide a vehicle anti-lock brake system that generates a braking force.

And it is a secondary object of the present invention by configuring a separate normal closed solenoid valve in the hydraulic line connecting the emergency master cylinder and the normal open solenoid valve and by constructing a pedal regenerator having a normal open solenoid valve at the inlet side thereof, During the normal braking operation, the hydraulic pressure generated from the emergency master cylinder flows into the pedal regenerator so that the driver can feel the braking action.The brake hydraulic pressure generated from the emergency master cylinder when the SR motor and the suction pump are not operated. It is to provide an anti-lock brake system for a vehicle to be directly transmitted to the brake to perform a braking action.

1 is a schematic diagram of a conventional anti-lock brake system.

2 is a schematic diagram of a vehicle anti-lock brake system according to the present invention.

3 is a control block diagram showing only an electrical configuration of the electric control apparatus of the vehicle anti-lock brake system according to the present invention.

4 is a system diagram showing a general braking process of the vehicle anti-lock brake system according to the present invention.

5 is a system diagram showing a process of releasing braking of an anti-lock brake system for a vehicle according to the present invention.

6 is a system diagram showing the emergency braking action of the vehicle anti-lock brake system according to the present invention.

7 is a system diagram showing a braking pressure decompression process of the vehicle anti-lock brake system according to the present invention.

8 is a system diagram showing a braking pressure boosting process of the vehicle anti-lock brake system according to the present invention.

9 is a system diagram showing a braking pressure maintenance process of the vehicle anti-lock brake system according to the present invention.

* Description of the symbols for the main parts of the drawings *

10. Brake pedal 20. Pedal sensor

30. Emergency master cylinder 31, 61 NC solenoid valve

35..Foot reproducer 33..Oil storage tank

40..SR motor 41..Suction pump

60, 34..NO type solenoid valve 70..NC type relief solenoid valve

The present invention for achieving the above object, the pedal sensor for detecting the operation of the brake pedal, the oil storage tank in which the oil is stored, the oil storage tank is associated with the emergency for forming hydraulic pressure in accordance with the operation of the brake pedal Master cylinders, brakes provided on the front and rear wheels of the vehicle to exert braking force by hydraulic pressure, 1NO type solenoid valves and 1NC type solenoid valves, respectively, provided on the inlet and outlet sides of the brake to control the flow of oil The SR motor, suction pump, and pedal sensor, which hydraulically pump the oil in the tank and deliver hydraulic pressure to the brake through the 1NO type solenoid valve, are electrically connected. An electric master controller that delivers hydraulic pressure to the brake by driving a pump The 2NC type solenoid valve which is provided in the hydraulic line connecting the 1NO type solenoid valve and the SR motor and the suction pump are not operated so that the hydraulic pressure formed by the action of the brake pedal in the emergency master cylinder is transferred to the brake. It is installed in the 2NC type solenoid valve inlet hydraulic line 32 so that the braking hydraulic pressure is formed in the emergency master cylinder so that the driver can feel the braking action when the driver presses the brake pedal and the emergency master when the SR motor and the suction pump are not operated. And a pedal reproducer provided with a second NO solenoid valve which is closed so that the braking hydraulic pressure formed in the cylinder is guided to the second NC solenoid valve side.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings. Figure 2 is a schematic diagram showing an anti-lock brake system for a vehicle according to the present invention, Figure 3 is a control block diagram showing only the electrical configuration of the electrical control apparatus according to the present invention.

Anti-lock brake system according to the present invention, as shown in the brake 80, 81, 82, 83 installed on each wheel and the brake pedal 10 is provided on one side of the driver's seat is interlocked by the driver's foot . Solenoid valves 60 and 61 are provided on the inlet and outlet sides of the brakes 80, 81, 82 and 83, respectively, to control the flow of hydraulic pressure, which is the first normally open solenoid valve 60 or less installed on the inlet side. And a first normal closed solenoid valve 61 (called a first NC solenoid valve) provided on the outlet side.

The operating shaft of the brake pedal 10 converts the oil in the oil storage tank 33 in which oil is stored and the oil in the oil storage tank 33 into hydraulic pressure during braking in an emergency, and the second NC solenoid valve 31 which will be described later. Emergency master cylinder 30 to be delivered to the brakes (80, 81, 82, 83) provided in each wheel through it is linked.

The hydraulic line 32 is provided at the outlet side of the emergency master cylinder 30 so as to be connected to the first NO solenoid valve 60 provided at the inlet side of the brakes 80, 81, 82, 83. On the inlet side of the solenoid valve 31 and the second NC solenoid valve 31, a pedal regenerator 35 is provided with a second NO solenoid valve 34. Therefore, when the brake pedal 10 is stepped on during the braking operation in the normal state, a braking hydraulic pressure is formed in the emergency master cylinder 30, and the braking hydraulic pressure is generated through the second NO solenoid valve 34. The driver can feel indirectly that the brakes (80, 81, 82, 83) are working. On the other hand, when the SR motor 40 and the suction pump 41 which will be described later do not operate, the second NO solenoid valve 34 is closed and the second NC solenoid valve 31 is opened to operate the emergency master cylinder ( The braking hydraulic pressure formed at 30 is transmitted to the brakes 80, 81, 82, and 83 to perform a substantial braking action, which will be described in detail in the operation description below.

On the other hand, the brake pedal 10 is provided with a pedal sensor 20 for detecting its operation and transmitting as an electrical signal to the electrical control device 100 to be described later to determine the braking pressure and the rising speed desired by the driver, the pedal sensor ( In operation 20, when the operation signal of the brake pedal 10 is input, the SR motor 40 and the suction pump 41 which are operated by the electric control device 100 to control the speed are connected to the oil storage tank 33. And hydraulic lines connecting the brakes (80,81,82,83). Reference numeral 50 denotes an accumulator and a damping chamber, 51 denotes an orifice, and 42 denotes a check valve provided on the inlet and outlet sides of the suction pump 41 to prevent backflow. Accordingly, when a signal in which the brake pedal 10 is operated is input from the pedal sensor 20 to the electric control device 100, the SR motor 40 and the suction pump 41 are operated, and the oil storage tank 33 is operated by the suction force thereof. Oil is forced into the hydraulic line and the suction pump 41 and discharged, and the pressure is changed linearly through the damping chamber 50 and the orifice 51, and the brake 80 through the first NO solenoid valve 60 81,82,83). In addition, an NC type solenoid valve 70 is provided in a hydraulic line connecting the 1NO solenoid valve 60 and the oil storage tank 33 to guide oil to flow back into the oil storage tank 33 when the braking pressure is released. have. Therefore, upon release of the braking action, the NC-type relief solenoid valve 70 is opened by the electric control device 100, and the oil is guided to the oil storage tank 33.

On the other hand, the pressure detection sensor 90 for detecting the braking hydraulic pressure in the hydraulic line to which the hydraulic pressure is delivered to the brakes (80, 81, 82, 83) by the pumping force of the suction pump 41 and transmitting it to the electric control device (100) Is installed, the driver detects the difference between the pressure and the pressure rising speed and the pressure and the pressure rising speed by the SR motor 40 and the suction pump 41 SR motor 40 and the suction pump 41 It is determined whether the additional operation and the opening operation of the NC-type relief solenoid valve 70. The configuration of the electric control device 100 will be described in more detail with reference to FIG.

First, a pedal sensor 20 and a pressure sensor 90 are connected to the input side of the electric control device 100, and on the output side thereof, the signals are input from the pedal sensor 20 and the pressure sensor 90. SR motor 40, suction pump 41, first and second NO solenoid valves 60 and 34, first and second NC solenoid valves 61 and 31 and NC type relief solenoid valve 70 It is electrically connected.

Therefore, when the brake pedal 10 is operated from the pedal sensor 20, the electric control device 100 drives the SR motor 40 and the suction pump 41, and is also input from the pressure sensor 90. As described above, the braking pressure is determined to determine whether the SR motor 40 and the suction pump 41 are additionally operated. At this time, when the braking pressure is excessively increased to operate the NC-type relief solenoid valve 70 to reduce the pressure.

Next, the general braking action of the vehicle antilock brake system according to the present invention will be described with reference to FIG. 4.

First, when the driver is decelerating the vehicle or wants to maintain the stopped state while driving or stopping the vehicle, the brake pedal 10 is stepped on. Accordingly, hydraulic pressure is generated in the emergency master cylinder 30 and is transmitted to the pedal reproducer 32 through the second NO solenoid valve. In other words, the braking hydraulic pressure is transmitted while the spring force inside the pedal reproducer 35 is transmitted, so that the driver can feel the braking. The pedal sensor 20 senses the braking pressure and the rising speed desired by the driver and controls the electric control device. The electrical signal is transmitted to 100.

Subsequently, the electric control apparatus 100 operates the SR motor 40 and the suction pump 41 based on the signal of the pedal sensor 20. According to the operation of the suction pump 41, the oil in the oil storage tank 33 receives positive high-pressure energy, and the pressure is linearly changed by the damping chamber 50 and the orifice 51 so that the first NO solenoid valve Through 60, the brakes 80, 81, 82, 83 of each wheel is hydraulically transmitted, causing a braking action.

At this time, if a difference between the pressure and the pressure rise rate actually generated by the suction pump 41 and the pressure and pressure rise rate desired by the driver in the signal input from the pressure sensor 90, the electric control device 100 In order to measure this difference, the SR motor 40 and the suction pump 41 are ordered to start or stop operation. That is, if the actual generated pressure and the pressure rise rate is small, the SR motor 40 and the suction pump 41 are additionally operated, and in the opposite case, the operation of the SR motor 40 and the suction pump 41 is stopped. Thus, the driver satisfies the desired pressure and the rising speed.

On the other hand, if the pressure is excessively increased so that the driver rises larger than the desired pressure, the electric control device 100 operates to open the NC-type relief solenoid valve 70 to reduce the pressure. In addition, even when excessive pressure is generated momentarily, the NC-type relief solenoid valve 70 is opened to prevent oil from damaging the brake system by moving the oil back into the oil storage tank 33.

Next, operation of the general braking force release of the vehicle antilock brake system according to the present invention will be described with reference to FIG. 5.

If the driver tries to reduce the braking force during braking or does not want the braking action, the driver reduces or eliminates the force for pressing the brake pedal 10. Accordingly, the brake pedal 10 is to be restored to its original position, and the oil inside the pedal regenerator 32 starts to move into the oil storage tank 33 via the emergency master cylinder 30. At the same time, the pedal sensor 20 transmits the position and the speed of the brake pedal 10 to the sensing electric control device 100. Here, the braking pressure, the braking pressure decreasing speed, and the braking desired by the driver based on the input signal. Determine complete pressure release. In addition, the electric control apparatus 100 performs the driver's braking force reduction, its reduction speed, and complete willingness through the NC-type relief solenoid valve 70. That is, as the NC-type relief solenoid valve 70 is opened, the hydraulic pressure of the brakes 80, 81, 82, and 83 is again supplied through the first NO-type solenoid valve 60 and the NC-type relief solenoid valve 70. Guided to the storage tank (33). At this time, it is possible to control the correct braking action by detecting the pressure control state through the pressure sensor 90, if the pressure reduction is greater than the driver's will to operate the NC-type relief solenoid valve 70 to close the SR motor (40) ) And the suction pump 41 are re-driven to raise the desired braking pressure.

And the braking action at the time of breakdown operation of the brake system will be described with reference to FIG. If a failure occurs in the SR motor 40 and the suction pump 41 during braking, driving and stopping of the vehicle, the electric control apparatus 100 may open the second NC solenoid valve 31 which is closed when the vehicle operates normally. The second NO solenoid valve 34 on the pedal reproducer 35 side is closed. In this state, when the driver presses the brake pedal 10 to brake, the emergency master cylinder 30 receives the oil from the oil storage tank 33 to form a braking hydraulic pressure, and the generated hydraulic pressure is an open hydraulic pressure. It is transmitted to the brakes 80, 81, 82, and 83 of the front wheel and the rear wheel through the line 32 and the 2NC type solenoid valve 31 which is opened. When the foot is released from the brake pedal 10 to release the braking action, the oil is returned through the second NC solenoid valve 31 in the reverse order of the braking action.

On the other hand, while the vehicle is being driven, the brakes are generated by the driver when the braking pressure is increased or maintained while the driver controls the braking force to increase or maintain the braking pressure due to the braking pressure (80,81,82,83). If the frictional force at) is greater than the braking force generated from the tire or the road surface of the vehicle, the wheels of the vehicle will slide on the road surface. Accordingly, the vehicle loses steering power and increases the braking distance, as well as the rotation of the vehicle, which requires ABS control. The ABS is controlled in three modes such as boost, depressurize, and maintain, and each control state is not controlled to the same state on all four wheels of the vehicle, but is controlled separately from the road condition and the ABS control state, that is, three modes. Is controlled by mixing.

First, the pressure reduction state of the vehicle anti-lock brake system according to the present invention will be described with reference to FIG. If the braking pressure in the brakes (80, 81, 82, 83) is greater than the road surface conditions in the state of braking is to be reduced to the appropriate pressure. Accordingly, in the electric control apparatus 100, the first NC solenoid valve 61 is opened to operate, so that the oil discharged from the brakes 80, 81, 82, and 83 is sucked back by the suction pump 41 or the oil storage tank. Inflow to (33). At this time, the opening operation of each of the first NC solenoid valves 61 is performed simultaneously or separately. Through this process, the pressure of the brakes 80, 81, 82, and 83 mounted on the vehicle wheels is lowered to prevent the wheels from sliding on the road surface.

Next, a pressure increase state of the vehicle antilock brake system according to the present invention will be described with reference to FIG. 8. If the ABS depressurization state lasts for a long time during ABS control or the vehicle progresses and moves to a place where the friction coefficient of the road is high, the vehicle tires and the road surface may be braked by the braking pressure in the brakes (80,81,82,83). The friction force that can be generated in the car increases, which reduces the braking efficiency of the vehicle. The electric controller 100 determines the situation and drives the SR motor 40 and the suction pump 41 to increase the braking pressure in the brakes 80, 81, 82, and 83. Accordingly, the oil discharged from the brakes 80, 81, 82, and 83 through the 1NC type solenoid valve 61 in the oil storage tank 33 and the ABS pressure-reduced state is suction-pumped to the suction pump 41 again. do. At this time, the suctioned oil is pressurized by the hydraulic pressure of the positive type but is converted into a linear pressure while passing through the damping chamber 50 and the orifice 51. This hydraulic pressure is continuously transmitted to the brakes 80, 81, 82, and 83 through the 1NO type solenoid valve 60 which is opened to increase the braking hydraulic pressure. On the other hand, if it is detected that the braking hydraulic pressure transmission is carried out more than necessary through the pressure sensor 90 in the ABS pressure boosting process, since the electric control device 100 opens the NC-type relief solenoid valve 70 to lower the pressure Damage to the brake system due to pressure rise is prevented.

In the ABS control, the pressure in the brakes 80, 81, 82, and 83 reaches the optimum pressure for generating the optimum braking force, or the pressure is kept constant to prevent the resonance of the vehicle derived from the ABS control. An operating state is required, with reference to FIG. 9 to describe the pressure holding process of the anti-lock brake system according to the present invention. The pressure holding state which prevents the pressure change in the brakes 80, 81, 82, and 83 mounted on the wheels of the vehicle is maintained among the first NO solenoid valves 60. Closing operation of the 1NO solenoid valve 60 on the side blocks the transmission of hydraulic pressure. On the other hand, when the hydraulic pressure is continuously transmitted from the suction pump 41 even in the ABS pressure holding state, the NC-type relief solenoid valve 70 is opened by the electric control device 100 and is discharged through the brake system due to the pressure increase. Damage is prevented.

In the vehicle equipped with the anti-lock brake system according to the present invention, even when the brake pedal 10 is advanced to the end, no sponge phenomenon and no vapor lock phenomenon occur. In addition, a booster or the like for generating the boost force by the pressure difference is not required, and since the braking of the vehicle is performed by the electrically operated SR motor 40 and the suction pump 41, precise braking control according to the driver's intention is achieved. Not only that, but also during the failure of the SR motor 40 and the suction pump 41, the braking hydraulic pressure is transmitted through the second NO solenoid valve 34 and the second NC solenoid valve 31 to perform a braking action.

As described in detail above, the vehicle anti-lock brake system according to the present invention comprises a pedal sensor for detecting the operation of the brake pedal, SR motor and suction pump installed in the hydraulic line connecting the oil storage tank and the brake, When the brake pedal is pressed, the SR motor and the suction pump are driven, and the oil in the oil storage tank is hydraulically transferred to each brake of the front wheel and the rear wheel by the pumping force of the suction pump to generate a braking force. Therefore, it is not necessary to use a booster to generate power by the pressure difference, which reduces the price of the overall brake system. Also, the braking of the vehicle is performed by driving the SR motor and the suction pump which are electrically operated. There is an advantage that can be performed according to the precise braking control.

In addition, a separate normal closed solenoid valve is provided in the hydraulic line connecting the emergency master cylinder and the normal open solenoid valve, and a pedal regenerator having a normal open solenoid valve is formed at the inlet side thereof. Accordingly, during the braking operation in the normal state, the hydraulic pressure generated from the emergency master cylinder flows into the pedal regenerator, so that the driver can feel the braking action, and when the SR motor and the suction pump are not operated, the emergency master cylinder is generated. The braking hydraulic pressure is transmitted directly to the brake to perform the braking action.

Claims (1)

A pedal sensor 20 for detecting the operation of the brake pedal 10, an oil storage tank 33 in which oil is stored therein, and an oil storage tank 33 are connected to the operation of the brake pedal 10. Emergency master cylinder 30 for forming hydraulic pressure, brakes (80, 81, 82, 83) are provided on the front and rear wheels of the vehicle to exert braking force by hydraulic pressure, the brakes (80, 81, 82, 83) The first NO solenoid valve 60 and the first NC solenoid valve 61 provided at the inlet side and the outlet side of the oil outlet to control the flow of hydraulic pressure, and the oil in the oil storage tank 33 is forcibly sucked and pumped. The SR motor 40, the suction pump 41, and the pedal sensor 20, which are hydraulically transmitted to the brakes 80, 81, 82, and 83 through a 1-NO solenoid valve 60, are electrically connected to the pedals. When the operation signal of the brake pedal 10 is input from the sensor 20, the SR Electric control device 100 for driving hydraulic pressure 40 and the suction pump 41 to transfer the hydraulic pressure to the brakes (80, 81, 82, 83), the emergency master cylinder 30 and the first NO type Action of the brake pedal 10 in the emergency master cylinder 30 when the SR motor 40 and the suction pump 41 are not operated provided in the hydraulic line 32 connecting the solenoid valve 60. Is provided in the 2NC type solenoid valve 32, the 2NC type solenoid valve 32, the inlet side hydraulic line 32, which opens so that the hydraulic pressure formed by the pump is transmitted to the brakes 80, 81, 82, and 83. When the brake pedal 10 is stepped on, the braking hydraulic pressure formed in the emergency master cylinder 30 is introduced so that the braking action can be felt, and the SR motor 40 and the suction pump 41 are not operated. The braking hydraulic pressure formed in the master cylinder 30 is the second NC type. Les cannabinoid claim 2NO-type solenoid valve 34 is provided to reproduce the pedal group vehicular anti-lock brake system, comprising a step of having a 35 to operate so that the closed side of the valve guide (32).