KR100328228B1 - Anti-lock brake system for vehicle - Google Patents

Abstract

PURPOSE: An anti-lock brake system for a vehicle is provided to perform ABS(Anti-lock Brake System) control by using an electronic control booster without a pump and an accumulator. CONSTITUTION: An anti-lock brake system for a vehicle comprises a servo(20); a master cylinder(30) having an oil storage tank(31) forming damping hydraulic pressure by the strength transmitted from the servo; brakes(60,61,62,63) receiving the damping hydraulic pressure and making damping force, with installed to front wheels and rear wheels; normal open solenoid valves(50,51,52,53) and normal close solenoid valves(40,41,42,43) for controlling the flowing of hydraulic pressure, with disposed at the inlet and outlet sides of the brakes; and an electronic control unit for controlling the opening and shutting motions of the normal open and closed solenoid valves. A pneumatic valve(21) opened and shut by the electronic control unit so that power distribution is formed at the servo. Therefore, the number of parts is reduced and the size of a modulator is reduced.

Description

Automotive Antilock Brake System

The present invention relates to a vehicle antilock brake system, and more particularly, to a booster of an antilock brake system for performing ABS control using an electronic control booster without the need for a pump and an accumulator.

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.

The conventional anti-lock brake system is a drum or caliper hydraulic brakes 9a, 9b, 9c, and 9d that generate braking force by hydraulic pressure to the front wheels FL, FR and the rear wheels RL and RR, respectively, as shown therein. It is installed and consists of a master cylinder (3) provided with a hydraulic power storage device (2) and the oil storage tank (3a) for forming a braking hydraulic pressure to deliver to the brakes (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 receives the amplified force from the power booster 2 to form a braking hydraulic pressure, and is connected to the brakes 9a, 9b, 9c, and 9d through a hydraulic line.

On the other hand, solenoid valves are provided on the inlet and outlet sides of the brakes 9a, 9b, 9c, and 9d to control the hydraulic pressure transmitted to the brakes 9a, 9b, 9c, and 9d. This is divided into normal-open solenoid valves 5a, 5b, 5c, and 5d arranged at the inlet side and normal-closed solenoid valves 4a, 4b, 4c and 4d arranged at the outlet side, and the electric control unit (ECU) It is controlled by si), and it shows strong and stable braking force. At this time, the electric controller (not shown) detects the vehicle speed through the wheel sensors (not shown) provided in the front wheel (FR, FL) and the rear wheel (RR, RL), and controls them.

First and second low pressure accumulators 6a and 6b are provided downstream of the normal closed solenoid valves 4a, 4b, 4c and 4d on the front wheels FR and FL and the rear wheels RR and RL. In the decompression mode, the oil discharged from the brakes 9a, 9b, 9c, and 9d is temporarily stored. In addition, the first and second high pressure accumulators 8a and 8b are disposed behind the first and second low pressure accumulators 6a and 6b, and a pair of first and second pumps 7a and 7b are disposed therebetween. ) Is configured to pressurize the low pressure oil in the first and second low pressure accumulators 6a and 6b to pump the first and second high pressure accumulators 8a and 8b. Reference numeral 7 denotes a motor for driving the first and second pumps 7a and 7b.

In the conventional anti-lock brake system configured as described above, when the driver presses the brake pedal 1 while driving, the back force is generated by the pressure difference in the power supply device 1a, and the master cylinder 3 receives the amplified force. To form hydraulic pressure. This hydraulic pressure is transmitted to the respective brakes 9a, 9b, 9c, and 9d provided at the front wheels FR and FL and the rear wheels RR and RL through the normally open solenoid valves 5a, 5b, 5c, and 5d. Will be

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 slides. This phenomenon is applied to the wheels mounted on the front wheels FR and FL and the rear wheels RR and RL. A sensor (not shown) senses and delivers it to an electrical control device (not shown) of the antilock brake system. Accordingly, in the electric control device (not shown), the normal closed solenoid valves 4a, 4b, 4c, and 4d are operated to open, thereby lowering the braking pressure by removing oil in the brakes 9a, 9b, 9c, and 9d. The oil discharged through the normally closed solenoid valves 4a, 4b, 4c, and 4d is moved to the first and second low pressure accumulators 6a and 6b and stored for a while, and the motor 7 is driven. The pressure rises again through the first and second pumps 7a and 7b, so that the first and second high pressure accumulators 8a and 8b and the master cylinder 3 or the normally open solenoid valves 5a, 5b and 5c Cycles back to 5d).

In the conventional anti-lock brake system, oil coming out of each of the brakes 9a, 9b, 9c, and 9d during the braking pressure decompression process is temporarily stored in the first and second low pressure accumulators 6a and 6b. It is discharged again by the drive of the 2nd pump 7a, 7b, and goes to the master cylinder 3. As shown in FIG. At this time, since the two first and second pumps 7a and 7b are driven with a phase difference of 180 degrees by one motor 7, the first and second pumps 7a and 7b are driven out of the front wheels FR and FL side brakes 9a and 9b. The oil stored in the first low pressure accumulator 6a and the oil stored in the second low pressure accumulator 6b are alternately pumped with a phase difference of 180 degrees. In addition, since the decompression mode of ABS does not simultaneously perform the front wheels FR and FL and the rear wheels RR and RL, when the oil flows into the first low pressure accumulator 6a, the second low pressure accumulator 6b is used. ) Also occurs when oil does not flow. In this state, when the first and second pumps 7a and 7b are driven, noise is generated due to a flow rate difference discharged from the first low pressure accumulator 6a and the second low pressure accumulator 6b. That is, since the oil inflow into the first low pressure accumulator 6a and the second low pressure accumulator 6b is made alternately, the amount of oil temporarily stored therein also alternately occurs. As a result, a difference occurs between the oil flow rate pumped from the first low pressure accumulator 6a to the first pump 7a and the oil flow rate discharged from the second low pressure accumulator 6b, thereby causing a braking action of the antilock brake system. Significant noise is generated during the process.

In addition, the first and second low pressure accumulators 6a and 6b, the first and second pumps 7a and 7b, and the first and second high pressure accumulators 8a and 8b are all modulators. All are provided in the body (not shown) of the not shown, there is a limit to the compactness of the modulator (not shown) due to these interiors.

The present invention is to solve this problem, the object of the present invention is to install a pneumatic valve controlled by the electric control device in the booster, a relatively strong power is generated according to the opening operation of the pneumatic valve in the boosting mode, The braking hydraulic pressure is strongly transmitted from the master cylinder to the forming brake by receiving the force, thereby providing an anti-lock brake system that performs the boosting braking action of the ABS control.

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

2 is a schematic diagram of an antilock brake system according to the present invention.

3 is a control block diagram showing only an electrical configuration of the electric control apparatus according to the present invention.

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

10. Brake pedal 20. Electric control device 30. Master cylinder

40. Normally closed solenoid valve 50. Normally open solenoid valve

70. Return hydraulic line 80. Electrical control 81. Wheel sensor

In order to achieve the above object, the present invention provides an oil storage tank for forming braking hydraulic pressure by a force transmitted from an external air flow in which external air is introduced by the operation of a brake pedal and a pressure is formed by a pressure difference device. A master cylinder, a brake provided at the front wheel and the rear wheel of the vehicle, respectively, to provide braking force by receiving braking hydraulic pressure, and a normally open solenoid valve and a normal closed solenoid valve that are provided at the inlet and outlet sides of the brake to control hydraulic flow. In the anti-lock brake system having an electric control device for controlling the opening and closing operation of the normally open solenoid valve and the normal open solenoid valve,

The booster is connected to a negative pressure source and is characterized in that the pneumatic valve is opened and closed by the electric control device so that the booster is formed in the booster.

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 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.

As shown in the antilock brake system according to the present invention, the brakes (60, 61, 62, 63) provided on the front wheel (FR, FL) and the rear wheel (RR, RL) and the brake pedal provided on one side of the driver's seat ( 10), the master cylinder 30 is provided with the booster device 20 and the oil storage tank 31 is provided to form a boost force by the operation of the pedal 10, thereby generating a braking hydraulic pressure. Solenoid valves are installed at the inlet and outlet sides of the brakes 60, 61, 62, and 63, respectively, to control the flow of hydraulic pressure, which is normally open solenoid valves 50, 51, 52, 53 installed at the inlet side and the outlet. Normally closed solenoid valves (40, 41, 42, 43) provided on the side.

And a return hydraulic line 70 connecting the discharge port side of the normal closed solenoid valves 40, 41, 42, and 43 on the front wheel FR, FL side and the rear wheel RR, RL side to the oil storage tank 31. This is provided. Therefore, when the normal closed solenoid valve (40, 41, 42, 43) is opened during the decompression braking, it is discharged from the front (FR, FL) and rear (RR, RL) brakes (60, 61, 62, 63). The oil is temporarily stored in the oil storage tank 31 through the return hydraulic line (70).

On the other hand, the power supply device 20 is provided with a pneumatic valve 21 is connected to the negative pressure source and opened and closed by the electric control device 80 to be described later. As a result, in the power supply device 20 during the opening operation of the pneumatic valve 21, the power generated by the operation of the pneumatic valve 21 is added in addition to the power generated by the differential pressure with the external air introduced by the brake pedal 10. As a result, a significant braking hydraulic pressure is formed in the master cylinder 30.

On the other hand, all the opening and closing operations of each solenoid valve and the pneumatic valve 21 is made by the electric control device 80, the configuration of the electric control device 80 will be described in more detail with reference to FIG. .

First, the wheel sensor 81 provided at the front wheel FR, FL and the rear wheel RR, RL is electrically connected to an input side of the electric control device 80, and a signal input from the wheel sensor 81 at its output side. Normally open solenoid valves (50, 51, 52, 53), normal closed solenoid valves (40, 41, 42, 43) and pneumatic valves (21) connected to each other are connected. Therefore, the braking pressure and the rising speed are controlled by detecting the rotation speeds of the front wheels FR and FL and the rear wheels RR and RL based on the signal input from the wheel sensor 81.

Next, a general braking operation of the vehicle antilock brake system according to the present invention configured as described above will be described.

The driver steps on the brake pedal 10 to decelerate the vehicle or maintain the stopped state while driving or stopping the vehicle. Accordingly, in the power supply apparatus 20, the power boosted by the pressure difference is amplified, and the braking hydraulic pressure of considerable pressure is generated in the master cylinder 30 by this force. The braking hydraulic pressure is transmitted to the brakes 60, 61, 62, and 63 provided on the front wheels FR, FL and the rear wheels RR, RL through the normally open solenoid valves 50, 51, 52, and 53, thereby braking. Work is done. When the driver releases the brake pedal 10 little or completely, the oil pressure in each brake 60, 61, 62, 63 is mastered again through the normally open solenoid valves 50, 51, 52, 53. The return to the cylinder 30 is reduced or the braking action is completely released.

Meanwhile, the brakes 60, 61, 62, 63 generated by the braking pressure when the driver makes the braking pressure larger than the road surface state or the road surface conditions are changed while controlling the braking force increase / hold state for the purpose of deceleration or stop while driving the vehicle. When the frictional force of Ess is greater than the braking force generated from the tire or the road surface of the vehicle, the wheels of the vehicle slide on the road surface. Accordingly, the vehicle loses steering power and increases the braking distance, and also requires ABS control because the vehicle rotates. The ABS is controlled in three modes, such as boost, depressurization, and maintenance, and each control state is not controlled to the same state on all four wheels of the vehicle, but is separately controlled according to the road condition and the ABS control state. The modes are mixed and controlled.

First, the pressure reduction operation of the vehicle anti-lock brake system according to the present invention will be described. If the braking pressure in the brakes (60, 61, 62, 63) is greater than the road surface conditions in the state that braking is being performed, it should be lowered to the appropriate pressure. Accordingly, in the electric control device 80, the normal closed solenoid valves 40, 41, 42, 43 are opened to operate, so that the brakes 60, 61, on the front wheel FR, FL side and the rear wheel RR, RL side are opened. The oil discharged from 62 and 63 is temporarily stored in the oil storage tank 31 through the return hydraulic line 70. At this time, the opening operation of each normal closed solenoid valve 40, 41, 42, 43 is performed simultaneously or separately. Through this process, the pressures of the brakes 60, 61, 62, and 63 mounted on the front wheels FR and FL and the rear wheels RR and RL are lowered, thereby preventing the sliding of the road surface.

And the pressure-increasing operation of the vehicle anti-lock brake system according to the present invention is as follows. If the ABS depressurization state lasts for a long time during ABS control or the vehicle moves to a place where the friction coefficient of the road surface is high, the vehicle tires and the road surface may be braked with the braking pressure in the brakes 60, 61, 62, and 63 The friction force that can be generated in the car increases, which reduces the braking efficiency of the vehicle. In this case, the electric controller 80 determines the situation based on the signals input from the wheel sensors 81, and the pneumatic valve 21 is increased to increase the braking pressure in the brakes 60, 61, 62, and 63. Open operation Accordingly, in the power supply apparatus 20, a force greater than the power generated by the operation of the brake pedal 10 is generated as the back force, and a strong braking hydraulic pressure is formed in the master cylinder 30 by this force. The braking hydraulic pressure is transmitted to the brakes 60, 61, 62, and 63 through the normally operated solenoid valves 50, 51, 52, and 53 that are opened, thereby increasing the braking hydraulic pressure.

In the ABS control, the pressure in the brakes 60, 61, 62 and 63 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 condition is required, the pressure holding operation of the anti-lock brake system according to the present invention is as follows. Normally open solenoid valves (50, 51, 52, 53) are used to maintain the pressure change in the brakes (60, 61, 62, 63) mounted on the front wheels (FR, FL) and rear wheels (RR, RL) of the vehicle. ) Closes the normally open solenoid valve (50, 51, 52, 53) of the brake (60, 61, 62, 63) to maintain the pressure to block the transmission of hydraulic pressure.

Therefore, the ABS pressure-increasing braking action during the braking operation of the anti-lock brake system according to the present invention is performed by the opening and closing operation of the pneumatic valve 21 provided in the power supply device 20, and the normal closed solenoid valve during the decompression braking action ( 40, 41, 42, 43 is opened and the oil exiting from the brake (60, 61, 62, 63) side is stored in the oil storage tank 31 through the return hydraulic line (70). As a result, since the body of the modulator (not shown) does not need the first and second low pressure accumulators, the first and second low pressure accumulators, and the first and second pumps, the overall size can be reduced.

As described in detail above, the anti-lock brake system according to the present invention, by installing a pneumatic valve controlled by the electric control device in the booster, a relatively strong power is generated in accordance with the opening operation of the pneumatic valve in the boosting mode, such a force The braking hydraulic pressure is strongly transmitted from the master cylinder to the brake, and the pressure-induced braking action of the ABS control is performed. As a result, the conventional low pressure accumulator, the high pressure accumulator, and the pump are not required, thereby reducing the number of parts and further reducing the body size of the modulator.

Claims (2)

An external air flows in accordance with the operation of the brake pedal 10 and the power storage device 20 is formed by the pressure difference, and an oil storage tank 31 which forms a braking hydraulic pressure by the force transmitted from the power supply device 20. ) Is provided in the master cylinder 30, the front wheels (FR, FL) and the rear wheels (RR, RL) of the vehicle, respectively, the brakes (60, 61, 62, 63) to exert braking force by receiving braking hydraulic pressure, the brake Normally open solenoid valves (50, 51, 52, 53) and normal closed solenoid valves (40, 41, 42) are provided at the inlet and outlet sides of (60, 61, 62, 63) to control hydraulic flow. 43), an anti-lock brake system having an electric control device (80) for controlling the opening and closing operations of the normally open solenoid valves (50, 51, 52, 53) and the normal open solenoid valves (40, 41, 42, 43). To The anti-lock brake is connected to the negative pressure source and is provided with a pneumatic valve 21 which is opened and closed by the electric control device 80 so that the boosting force is formed in the boosting device 20. system. The method of claim 1, One end is connected to the outlet side of the normal closed solenoid valves (40, 41, 42, 43) and the other end is provided with a return hydraulic line (70) connected to the oil storage tank (31) during the decompression braking operation Oil coming out of the brakes (60, 61, 62, 63) in accordance with the opening operation of the closed solenoid valve (40, 41, 42, 43) through the return hydraulic line (70) the oil storage tank (31) Anti-lock brake system, characterized in that the flow into.

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