KR20000000538A - Brake device for car - Google Patents

Abstract

PURPOSE: A brake device for a car is provided to reduce the tiredness of a driver by preserving a brake function even though removing a foot from a brake pedal after completely stopping the car to step on a pedal of the brake. CONSTITUTION: The brake device for a car comprises:an oil pressure cylinder(80), divided into an air chamber(84) and an oil pressure chamber(86) by a piston(82); an orifice(74) to flow the brake oil of an oil tank to a pressure chamber(86) by forming an orifice(74) connected with a flow route(72) of a solenoid valve(70); a core valve(78) having an elasticity of a spring(77).

Description

Brake system

The present invention relates to a brake device for a vehicle. More particularly, the brake function is maintained even when the driver presses the brake pedal to stop the vehicle and then releases the brake pedal. It is to provide a brake device that is released so that the vehicle can start.

An automobile brake system is useful for decelerating or stopping a vehicle while driving and maintaining a parking state.

In the automobile brake system, the hydraulic brake is the piston in the master cylinder presses the brake fluid to the wheel cylinder when the driver presses the brake pedal, and the wheel cylinder receives the hydraulic pressure and compresses the brake shoe to the drum by spreading the piston left and right. Since the hydraulic pressure in the master cylinder decreases when the foot is released from the brake pedal, the brake shoe returns to its original position by the reaction force of the spring, and the brake fluid in the wheel cylinder returns to the master cylinder to release the brake action.

However, in the hydraulic brake, there is a drawback that if the hydraulic system breaks down, such as liquid leakage, it becomes impossible to brake. Therefore, various safety devices have been adopted in automobiles to ensure a certain amount of braking force when the brake system fails.

The brake safety device includes a device that prevents accidents by securing a certain amount of braking force when the brake system is damaged (two-type brake), and prevents rear wheels from skidding and become unstable during braking. (anti skid device) and all the wheels to prevent skids to prevent the instability during braking and at the same time to improve the braking device.

As an example, the Tandem Master Cylinder, in which the push rod is advanced by the boosted force of the power brake to generate oil pressure in the hydraulic line of the brake, is divided into two oils for separating the hydraulic system for the front wheel and the rear wheel. If a system is equipped with a tank and a failure occurs, the other system can be braked to increase stability.

As shown in FIG. 1, the first and second pistons 20 and 22 are mounted in a line in the same structure as that of two master cylinders arranged in series, that is, one tandem master cylinder 10 having the same inner diameter. The primary piston 20 is one end is supported by the push rod 30, the other end is supported by the compression spring 40 and the secondary spring 22 is both supported by the compression spring (40, 44), respectively The reaction force of the compression springs 40 and 44, and the brake oil of the front pressure chamber 50 in which the compression springs 40 are mounted is the front wheel cylinder, and the rear pressure chamber in which the compression springs 44 are mounted. The brake oil of 55 is adapted to operate the rear wheel cylinder.

The tandem master cylinder 10 is provided with return ports, reservoir ports, and outlet check valves corresponding to the respective pistons 20 and 22, and the check valves installed at the primary and secondary sides have oil in the cylinder front and rear. Only when the brake is released to the wheel cylinder, when the brake is released, the oil is released from the sheet until the tension between the hydraulic pressure in the circuit and the springs (50, 55) is balanced and the oil is returned to the cylinder (10). It is designed to keep the residual pressure in the circuit to speed up the operation, to prevent oil leakage from the wheel cylinder, and to prevent vapor lock.

In the tandem master cylinder 10 configured as described above, when the driver presses a brake pedal (not shown), the primary piston 20 is advanced in one direction by the push rod 30 as shown in FIG. The brake oil of 50) is compressed, and the hydraulic pressure pushes the secondary piston 22 and simultaneously activates the brake of the rear system. In addition, the secondary piston 22 pushed by the hydraulic pressure compresses the brake oil of the piston front pressure chamber 55 to operate the brake of the front system.

On the contrary, when the brake pedal is released, the push rod 30 moves backwards, and each piston is returned to its original position by the compression springs 50 and 55 and the hydraulic pressure to release the hydraulic pressure of the front and rear brake lines, and the brake fluid Will be returned to the oil tank (60, 66).

On the other hand, if there is a liquid leak in the rear brake system, even if the brake pedal is pressed, the pressure chamber 50 between the primary piston 20 and the secondary piston 22 does not generate hydraulic pressure, so the front of the primary piston 20 The front end pushes the secondary piston 22 directly to operate only the front brake system, and if there is a liquid leak in the front brake system, hydraulic pressure does not occur in the pressure chamber 55 located in front of the secondary piston 22. The tip of the car piston 22 is in contact with the cylinder 10 and the hydraulic pressure is generated in the pressure chamber 55 between the primary piston 20 and the secondary piston 22 to operate only the rear brake system.

Therefore, in the case of manual transmission cars, the driver keeps stepping on the brake pedal so that the vehicle can be stopped for a congested road or waiting for a signal, and the driver easily feels fatigue when repeated several times, especially for inexperienced beginners. In the case of stopping a car on a hill road, when the foot pedal is removed from the brake pedal that has been stepped up to start again, the moment when the foot is moved to the accelerator pedal, the braked vehicle is pushed back and causes a back accident with the rear car.

In addition, in the case of an auto transmission car, if the driver inadvertently releases the brake after the driver stops the car temporarily and the position of the transmission is set to 'D' (departure), there is a problem such that the vehicle proceeds to cause a contact accident with the front car. .

The conventional problem as described above originates from the fact that the brake is configured to operate only in a state where the driver presses the brake pedal.

The object of the present invention is to add a separate device to the tandem master cylinder of the brake safety device in order to solve the above-mentioned problems, even if the driver presses the brake completely after the vehicle is completely stopped, the brake may be released. It is to provide a brake device that maintains the same brake function as if the pedal is continuously pressed, and brakes are released when the pedal is pressed again for driving the vehicle after stopping.

In order to achieve the above object, in the present invention, a hydraulic cylinder 80 having a solenoid valve 70 having a check valve function is installed at one side of a tandem master cylinder 10 of a vehicle brake safety device so that a driver presses a brake pedal. Stops, the solenoid valve shuts off the flow path between the oil tank and the hydraulic chamber of the hydraulic cylinder so that the hydraulic pressure of the wheel cylinder can be maintained, so that the brake function is maintained even when the brake pedal is released. The brake is released so that the car can start.

The inside of the hydraulic cylinder 80 is divided into the air chamber 84 and the hydraulic chamber 86 by the piston 82, the hydraulic chamber 86 is connected to the flow passage 72 of the solenoid valve 70 The orifice 74 is formed so that the brake oil of the oil tank flows to the pressure chamber 86 through the orifice 74, the piston 82 of the hydraulic cylinder 80 of the tandem master cylinder 10 Connected to the secondary piston 22 and interlocked together, the core 72 of the solenoid valve 70 retains the elasticity of the spring 77 is installed in the ECU connected to the electronic control unit of the vehicle The solenoid valve 70 driven by the core valve 78 closes the orifice 74 to lock the pistons 22 and 82 so that the hydraulic pressure of the wheel cylinder can be maintained. .

1 is an exemplary view of a conventional brake device;

2 is an operating state diagram showing an operation relationship of a conventional brake device;

3 is an exemplary view of a brake device for a vehicle to which the present invention is applied;

4 is an operational state diagram of the present invention;

5 is a block diagram of a brake device for a vehicle according to the present invention;

<Explanation of symbols for main parts of the drawings>

10: Tandem Master Cylinder 20, 22, 82: Piston

21,24: Return port 30: Push rod

40,44: compression spring 50,55,86: pressure chamber

60, 66: oil tank 70: solenoid valve

72: Euro 74: Orifice

76: flexible hose 78: core valve

79: magnetic 80: hydraulic cylinder

84: air chamber

According to the present invention, the solenoid is fixedly provided with a hydraulic cylinder 80 having a solenoid valve 70 having a check valve function at one end of a tandem master cylinder 10 of a known vehicle brake safety device as shown in FIG. 3. The secondary piston 22 of the tandem master cylinder 10, which is interlocked with the piston 82 in the hydraulic cylinder 80 by the valve 70, is also locked together so that the hydraulic pressure of the wheel cylinder can be maintained. It is designed to maintain the same brake function as pressing the pedal.

The tandem master cylinder 10 extends the secondary piston 22 rod 220 in one direction (hydraulic cylinder side), and the rod 220 is fixed to one side of the tandem master cylinder 10. The piston 82 of the 80 is fixed to the piston 82 of the hydraulic cylinder 80 together with the secondary piston 22 so as to interlock and move.

In addition, the hydraulic cylinder 80 is divided into two parts into the hydraulic chamber 86 into which the oil of the air chamber 84 and the oil tank 66 flows in by the piston 82, and the hydraulic chamber 86. An orifice 74 is provided in communication with the flow path 72 of the solenoid valve 70, and a flexible hose 76 connected to the oil tank 66 is connected to the flow path 72 to connect the oil tank 66. The oil can move freely to the pressure chamber 86 on the rear side of the piston 82 via the flow passage 72 and the orifice 74 of the solenoid valve 70.

The core 72 of the solenoid valve 70 has a core valve 78 having one end thereof retaining the elasticity of the spring 77, and the core valve 78 has a magnetic 79 of the solenoid valve 70. The linear movement is performed along the flow path 72 by the following.

Therefore, as the power is applied (“ON”) to the solenoid valve 70 and the magnetic 79 is excited, the core valve 78 moves as shown in FIG. 4 to move the orifice 74 connected to the hydraulic chamber 86. As the orifice 74 is blocked, the oil is introduced into the back pressure chamber 86 of the piston 82 and the piston 82 does not return to its original position and locks, and the power is shut off ("OFF"). If the core valve 79 is returned to its original position by the reaction force of the spring 77, and the orifice 74 is opened, the oil on the back side pressure chamber 86 of the piston 82 passes through the orifice 74. Upon returning to the oil tank 66, the locked state is released, and the brake function is also released.

5 is a block diagram showing a schematic configuration of a brake device.

As shown in the figure, a solenoid valve 70 is provided with a control relay, the control relay is connected to the ECU, and the ECU is connected to various electronic control units of the vehicle so that the ECU supplies power to the control relay according to each electric signal. It is supposed to supply / block

Idle switches, brake switches, vehicle speed sensors, clutch position detection switches and the like are used for the various electronic control units connected to the ECU. When the electrical signals transmitted from the electronic control unit coincide with the signals set in the ECU, the ECU controls them. Sending an operation signal to the relay to turn ON the control relay, the current is energized to the solenoid valve 70, the core valve driven by the magnetic 79 is excited as the current is energized to the solenoid valve 70 ) Is moved along the flow path 72 to block the orifice 74 so that no oil enters or exits the hydraulic chamber any more and is sealed off.

Therefore, as the piston 82 of the hydraulic cylinder 80 is locked in its current position, the secondary piston 22 of the tandem master cylinder 10 linked thereto is also locked together so that the hydraulic pressure of the wheel cylinder is maintained as it is. It is preserved to maintain the brake function.

<Example 1>

Conditions under which the solenoid valve 70 of the brake device operates to make the brake locked are as follows.

-Press the brake pedal to turn the brake switch "ON".

-The vehicle speed should be "0" (ZERO) (detected from the vehicle speed sensor)

-Idle switch is in the "ON" state (meaning the engine is idle).

In addition, when the vehicle is completely stopped and the trolley valve is in the idle position, the contact of the idle switch is in the "ON" state.

When the above conditions are input to the ECU from the brake switch, the vehicle speed sensor, and the idle switch, the ECU sends an operation signal to the solenoid valve. When the control relay is "ON" by this signal, the solenoid valve is energized and the solenoid valve is activated to brake. Can be automatically locked.

Even when the brake pedal is released and the brake switch is turned "OFF" under the electric brake lock condition, the circuit is configured so that the brake is always locked when the second and third conditions are met.

<Example 2>

The brake release condition in the brake lock state in the auto transmission vehicle is as follows.

-The position of the transmission converter lever should be other than P (stop) and N (neutral).

-Idle switch is in the "OFF" state. (This state is the state where the driver presses the accelerator pedal and the draw valve is opened. In this state, the idle switch is gradually dropped and the idle switch is in the "OFF" state.)

<Example 3>

The brake release condition in the brake lock state in the manual transmission vehicle is as follows.

-The idle switch is in the "OFF" state. Or the shift lever is in a position other than the neutral position (detected by the shift lever neutral position sensor, and the brake is released even when the accelerator pedal is pressed while the brake is locked and the shift lever is in the neutral position). To prevent installation)

-The idle switch is in the "OFF" state.

All the sensors and switches used to detect the brake lock and release conditions can be attached to the existing vehicle (but the shift lever position detection sensor of the manual transmission must be newly installed).

Even when the brake pedal is released and the brake switch is turned "OFF" under the electric brake lock condition, the circuit is configured so that the brake is always locked when the second and third conditions are met.

Hereinafter, the operational effects of the present invention will be described.

When the driver presses the brake pedal, the primary piston 20 is moved by the push rod 30, and at this time, the primary piston 20 blocks the primary return port 21 so that the secondary pistons 22 are separated. When hydraulic pressure is generated in the brake oil to operate the wheel cylinder of the rear wheel, and the pressure of the primary piston 20 is greater than the tension of the secondary compression spring 44 supporting it, the secondary piston 22 lifts the spring 44. Compresses and moves to the left. At this time, the secondary piston 22 blocks the secondary return port 24 to generate oil pressure in the hydraulic line of the front brake system so that the wheel cylinder of the front wheel is operated. Hydraulic pressure is generated in the vehicle side at the same time as in the prior art.

However, in the present invention, as the secondary piston 22 of the tandem master cylinder 10 moves to the left side, the piston 82 of the hydraulic cylinder 80 connected thereto is connected to the air chamber 84 together with the secondary piston 22. To the hydraulic chamber 86 of the oil tank 66 by increasing the volume and increasing the volume in the hydraulic chamber 86 as the piston 82 moves to the air chamber 84. As it is replenished, the hydraulic chamber 86 is always filled with oil.

As such, when the vehicle is completely stopped by the brake pedal (the state of the speed "0"), the ECU which detects this sends an electric signal to the control relay to apply current to the solenoid valve 70.

The magnetic 79 excited by the current energized by the solenoid valve 70 pushes the core valve 79 to the right as shown in FIG. 4, and the core valve 79 moving to the right is connected to the hydraulic chamber 86. The orifice 74 to be connected is blocked so that the hydraulic chamber 86 side is closed.

In this state, even when the brake pedal is released, the oil is stuck in the hydraulic chamber 86 at the rear of the piston 82, and the piston 82 is locked at the current position due to the incompressible nature of the oil. In addition, the secondary piston 22 of the tandem master cylinder 10 linked thereto is also locked so that the hydraulic pressure of the wheel cylinder is preserved to maintain the brake function.

When power is applied to the solenoid and the brake pedal is released while the piston 82 is locked, as shown in FIG. 4, the secondary piston 22 is also locked in the state together with the piston 82, thereby maintaining the front brake function. In this case, since the pushing force of the push rod 30 is released, the hydraulic pressure of the wheel cylinder of the rear wheel is lowered as the primary piston 20 moves by the restoring force of the compression spring 40. At this time, the primary piston 20 is moved until the sum of the tension of the compression spring 40 and the residual pressure in the pressure chamber is in equilibrium with the negative pressure generated due to the increase in the volume in the pressure chamber.

In this state, any residual pressure remains in the rear wheel cylinder so that the braking force is maintained on the rear brake. In addition, when the vehicle is pushed due to the lack of braking force and abnormality in the front brake, press the brake pedal again to generate hydraulic pressure in the rear brake to obtain the braking force.

As described above, according to the present invention, by adding a separate device to the tandem master cylinder of the vehicle brake device, the driver brakes on the same brake as if the driver continues to press the brake pedal even after the vehicle is completely stopped. Maintaining the function has the advantage that the fatigue of the driver to continuously press the brake pedal as in the prior art is greatly reduced.

In addition, the present invention has the effect that it can be used very useful for beginners who are somewhat inexperienced because the car is not pushed back when the vehicle is started again after being suspended from the hill.

The present invention having such a configuration and action effect can be very usefully used for industrial machines having similar functions and not for automobiles.

Claims (6)

On one side of the tandem master cylinder 10 of the vehicle brake safety device, a hydraulic cylinder 80 having a solenoid valve 70 having a check valve function is fixedly installed. When the driver steps on the brake pedal and the vehicle is stopped, the solenoid valve The flow path between the oil tank and the hydraulic cylinder of the hydraulic cylinder is blocked so that the hydraulic pressure of the wheel cylinder is maintained.The brake function is maintained even when the brake pedal is released.The brake is released by pressing the accelerator pedal to start again. Vehicle brake system characterized in that. The hydraulic cylinder (80) of claim 1, wherein an inner side of the hydraulic cylinder (80) is divided into an air chamber (84) and a hydraulic chamber (86) by a piston (82), and the hydraulic chamber (86) of the solenoid valve (70). An orifice 74 is formed to be connected to the flow path 72 so that the brake oil of the oil tank flows into the pressure chamber 86 through the orifice 74, and the piston 82 of the hydraulic cylinder 80 is tandem. Connected to the secondary piston 22 of the master cylinder 10 is interlocked with each other, the core 72 of the solenoid valve 70 has a core valve 78 retaining the elasticity of the spring 77 is built in the The solenoid valve 70 driven by the ECU connected to the electronic control unit is configured to maintain the hydraulic pressure of the wheel cylinder as the core valve 78 closes the orifice 74 to lock the pistons 22 and 82. Vehicle brake device characterized in that. 3. The vehicle according to claim 2, wherein the brake device presses the brake pedal to turn the brake switch and the idle switch in the "ON" state and the solenoid valve is energized so that the brake is locked only when the vehicle speed is "0". Brake device. The brake locked by the brake device is released when the position of the transmission conversion lever is in a position other than P (stop) and N (neutral), and is released when the idle switch is in the "OFF" state. Vehicle brake device. 4. The brake device according to claim 3, wherein the brake locked by the brake device is released when the idle switch is in the "OFF" state. 4. The brake device according to claim 3, wherein the brake locked by the brake device is released when the idle switch is in the "OFF" state or the shift lever is in a position other than the neutral position.