KR20130087198A - Motor booster of vehicle brake system - Google Patents

Abstract

The present invention relates to a brake system capable of providing a backing force of a brake pedal to a master cylinder without a vacuum generator.
The brake system according to the present invention includes a power unit for outputting an electric signal when the driver operates the brake pedal to operate the motor and converting the rotational movement of the motor into a linear movement; A hydraulic unit for braking the wheel with the force generated by the rear force unit; And a simulator unit provided to provide a reaction force according to the pedal force of the brake pedal.

Description

Motor booster of vehicle brake system

The present invention relates to a booster of a brake system, and more particularly to a booster of a brake system using a motor.

Recently, development of hybrid vehicles, fuel cell vehicles, electric vehicles, and the like are actively being carried out in order to improve fuel efficiency and reduce exhaust gas. Such a vehicle is essentially provided with a brake system, that is, a braking device, where the brake system of the brake system refers to a device that functions to reduce or stop the speed of the running vehicle.

1 is a view schematically showing a conventional brake system.

Referring to FIG. 1, the brake system 1 converts the pressure amplified from the brake pedal 1, the vacuum booster 10 to amplify and output the pedal force of the brake pedal 1, and the hydraulic pressure booster 10 to hydraulic pressure. Is connected to the master cylinder 20, the master cylinder 20 and the hydraulic pipe 24 is provided with a hydraulic control device 26 for transmitting and controlling the braking hydraulic pressure to each wheel cylinder (28).

Since the brake system needs to supply the suction pressure of the vehicle engine to the vacuum power booster 10 in order to form a vacuum, a separate engine or the vacuum generator 30 must be provided.

However, in an EV (Electronic Vehicle) vehicle that does not have an engine which is a general vacuum generator or a Hybrid (Hybrid) vehicle in which the engine does not operate at all times, a back pressure that satisfies the braking force of the vehicle is not provided when a separate vibration generator 30 is not installed. There is a problem that it is difficult to create.

In addition, in recent years, a brake system using a motor has been developed in place of the vacuum booster 10, but when the driver directly operates the brake by using the motor, when the driver steps on the brake pedal 1, the pedal according to the driver's pedaling force There is a problem that can not convey sense.

The present invention has been made to solve the above problems, an object of the present invention is to provide a brake system that can transfer the power of the brake pedal to the master cylinder using a motor without a vacuum generator.

Another object of the present invention is to provide a brake system that can improve the feeling of pedal by providing a repulsive force according to the pedal force of the brake pedal.

In order to achieve the above object, the brake system of the present invention, when the driver operates the brake pedal outputs an electric signal to the motor to operate the power unit for converting the rotational movement of the motor into a linear movement; A hydraulic unit for braking the wheel with the force generated by the rear force unit; And a simulator unit provided to provide a reaction force according to the pedal force of the brake pedal.

Preferably, the hydraulic unit, the master cylinder for generating the hydraulic pressure by the pressure according to the linear movement of the power unit, a reservoir coupled to the upper portion of the master cylinder to store the oil, and the master cylinder and the hydraulic pipe is connected to each Hydraulic control device for transmitting and controlling the braking hydraulic pressure to the wheel cylinder.

Preferably, the power unit, the sensor for sensing the operation of the brake pedal; A motor having a rotor and a stator for generating a rotational force by an electrical signal of the sensor; A ball screw member consisting of a screw and a ball nut for converting the rotational motion into a linear motion; And an electronic control unit configured to control the motor by receiving the braking will according to the driver's step force through the sensor, wherein the ball nut is installed to rotate together with the rotor to linearly move the screw. Compresses the master cylinder according to the linear motion in contact with the master cylinder and has a hollow hollow in the longitudinal direction.

Preferably, the simulator unit, the chamber housing is provided in the hollow portion of the screw, the one side is open to be connected to the brake pedal having a simulation chamber therein; A plunger disposed coaxially with the master cylinder to be advanced by the driver's stepping force and provided in the chamber housing, and a part of which is disposed in the hollow portion of the screw through the chamber housing; And a pedal simulator connected to the simulation chamber and a flow path to provide reaction force to the brake pedal.

The control valve may further include a control valve disposed in a flow path connecting the simulation chamber and the reservoir to control oil flowing between the simulation chamber and the reservoir.

Preferably, the control valve is a normally open solenoid valve which is open as a shut-off valve and operates to close the valve upon receiving a closing signal.

Preferably, the simulation chamber is provided with a spring for returning the plunger.

Preferably, it is made to have a constant clearance between the master cylinder and the end of the plunger located in the hollow portion of the screw.

Preferably, in abnormal operation of the brake system, the plunger moves at a distance spaced apart from the master cylinder and then mechanically contacts the master cylinder to transmit the force applied to the plunger.

The brake system according to the present invention effectively transfers the brake pedal power to the master cylinder of the hydraulic unit by using a motor rather than a vacuum booster, thereby providing stable back pressure in the hydraulic unit of the brake system even in an EV or hybrid vehicle without an engine. can do.

In addition, by providing a pedal simulator that is connected to the reservoir, it is possible to provide an appropriate pedal feeling to the driver by providing a repulsive force according to the pedal effort.

In addition, the driver's foot force is directly transmitted to the master cylinder during abnormal operation of the brake system, thereby providing a stable braking force.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail with reference to the following drawings, which illustrate preferred embodiments of the present invention, and thus the technical idea of the present invention should not be construed as being limited thereto.
1 is a view schematically showing a conventional brake system.
2 is a view schematically showing a brake system according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

2 is a view schematically showing a brake system according to a preferred embodiment of the present invention.

Referring to FIG. 2, the brake system according to the present invention senses the operation of the brake pedal 1 and outputs a boost signal, and the braking of the wheel by the force generated from the boost unit 100. A general hydraulic unit 200 to perform, and a simulator unit 300 for providing a reaction force according to the stepping force of the brake pedal (1).

The power booster 100 receives the sensor 101 for detecting the amount of operation of the brake pedal 1, the motor 110 generating a rotational force in response to the signal of the sensor 101, and the rotational force of the motor 110. Ball screw member 120 for converting the motion to a linear motion, and an electronic control unit (not shown) for controlling the motor 110 receives the braking will according to the driver's stepping force through the sensor 101.

The sensor 101 may be a sensor for measuring the pedaling force of the pedal 1 applied to the brake pedal 1, a sensor for detecting the stroke of the pedal 1, or the like. Such a sensor outputs a power boost signal through an electronic control unit (not shown).

The electronic control unit is a device that controls the motor 110 by receiving a braking intention according to the driver's stepping force through a sensor, and controls various operations of the motor such as driving and stopping, forward rotation, and reverse rotation of the motor 110. do. The electronic control unit may be separately provided in the power supply unit 100 to control the motor 110 and the control valve 340 to be described later, but may be installed and used in the hydraulic control unit 230 of the hydraulic unit 200.

The motor 110 is an electric motor that generates a rotational force through the signal output from the electronic control unit, and generates a rotational force in the forward or reverse direction by the electronic control unit. The motor 110 is provided with a case 111, a rotor 112 provided inside the case 111, and a plurality of magnets 113 mounted on an annular yoke (ferrule) along an outer circumferential surface thereof, and the rotor 112. It is a commonly used technique having a stator 114 spaced at regular intervals to surround the rotor 112. That is, a coil (not shown) is wound around the stator 114 surrounding the rotor 112. When power is applied to the coil 112, a repulsive force and an attractive force act between the magnet 113 and the coil so that the rotor 112 rotates. do. Since the motor 110 is well known in the art, a detailed description thereof will be omitted.

On the other hand, the ball nut 123 of the ball screw member 120 for rotating and transmitting the rotational force is installed in the center of the rotor 110. That is, the ball nut 123 serves to linearly move the screw 121 to be described later together with the role of the rotation shaft of the motor 110.

The ball screw member 120 is a screw nut rotatably coupled through a screw 121 having a spiral groove 122 formed on an outer circumferential surface thereof, and a spiral groove 122 of the screw 121 and a plurality of balls 124. It consists of 123. At this time, the ball nut 123 is installed in the center of the rotor 112 as described above is installed to rotate with the rotor 122.

In addition, the screw 121 has a predetermined length, and one end thereof is in contact with the master cylinder 210. Although not shown, a piston for generating braking hydraulic pressure is provided in the master cylinder 210, and the screw 121 is in contact with the piston to pressurize the piston so that braking is performed. That is, the screw 121 receives the rotational force in accordance with the forward and reverse rotation of the ball nut 123 is a linear movement in the longitudinal direction. Therefore, the back force generated when the motor 110 is driven is transmitted to the hydraulic part 200 through the linear movement of the screw 121.

On the other hand, according to the present invention, the screw 121 is a hollow portion 125 is formed along the longitudinal direction. The hollow part 125 is formed to install the chamber housing 310 of the simulator 300 to be described later, which will be described later.

The hydraulic unit 200 is coupled to the upper portion of the master cylinder 210 and the master cylinder 210 to form the hydraulic pressure as the pedal force of the brake pedal 1, for example, the back pressure of the motor 110 is transmitted to store the oil The reservoir 220 and a hydraulic control unit 230 for selectively transmitting the braking hydraulic pressure of the master cylinder 210 to the wheel cylinder 240 side. At this time, the hydraulic control device 230 is made of a modulator block that functions as a conventional ABS or ESC system that receives the braking hydraulic pressure from the master cylinder 210 through the hydraulic pipe 214 to control the braking hydraulic pressure. Since the configuration of the hydraulic unit 200 is the same as a brake system using a conventional vacuum booster, a detailed description thereof will be omitted.

According to the present invention, the simulator unit 300 is provided to solve a problem in which a pedal feeling of the brake pedal 1 cannot be formed by forming a back force using the motor 110, and includes a pedal simulator 330. .

More specifically, the simulator unit 300 is disposed coaxially with the master cylinder 210 so as to move forward by the driver's effort and the chamber housing 310 in which the simulation chamber 312 is provided therein and in the chamber housing 310. The plunger 320 is provided, and the pedal simulator 330 is connected to the simulation chamber 312 by a flow path to provide reaction force of the brake pedal 1.

The chamber housing 310 is provided such that the plunger 320 is retractable therein. In this case, an opening for contacting the push rod 2 of the pedal 1 and the plunger 320 is formed at one side of the chamber housing 310. In addition, the plunger 320 is configured to be disposed in the hollow portion 125 of the screw 120 after a portion passes through the other side of the chamber housing 310.

As shown, the plunger 320 is retractable in the chamber housing 310 and extends toward the inner side of the chamber housing 310, and is integrally formed with the flange 322 to form the chamber. The pressure rod 321 is disposed in the hollow portion 125 of the screw 120 through the housing 310. The flange 322 is connected to the push rod 2 of the brake pedal 1 through the open portion of the chamber housing 310, the pressure rod 321 and the piston (not shown) of the master cylinder 210 It is prepared to be spaced apart at regular intervals. That is, a constant clearance is formed between the piston (not shown) provided in the master cylinder 210 and the plunger 320. This is for the brake system according to the present invention to transfer the stepping force directly to the master cylinder 210 by mechanical contact with the master cylinder 210 after the plunger 320 moves by the spaced interval during abnormal operation. The operation of the plunger 320 will be described again below.

On the other hand, the simulation chamber 312 is provided with a spring 314. The spring 314 serves to return the plunger 320, which is moved according to the pedaling force of the brake pedal 1, to its original position. Accordingly, the plunger 320 is in contact with the push rod 2 installed on the pedal 1 to slide forward and backward with the push rod 2 by the pedaling force of the pedal 1. At this time, pressure is generated in the simulation chamber 312 according to the displacement of the plunger 320 disposed in the simulation chamber 312.

The pedal simulator 330 is connected to the simulation chamber 312. The pedal simulator 330 includes a chamber 331 and a reaction force piston 332 and a reaction force spring 333 are provided in the chamber 331. That is, the pedal simulator 330 moves the plunger 320 with the movement of the push rod 2 when the driver presses the pedal 1, and the pressure generated in the simulation chamber 312 moves the reaction force piston 332. The reaction force spring 333 is elastically compressed. At this time, the elastic force compressed by the reaction force spring 333 provides a reaction force to the plunger 320 and the push rod 2 to provide an appropriate pedal feeling to the driver.

On the other hand, the simulator 300 according to the present invention is disposed in the flow path connecting the simulation chamber 312 and the reservoir 220 is a control valve 340 for controlling the oil flowing between the simulation chamber 312 and the reservoir 220 It is further provided.

The control valve 340 is a shut-off valve, in which the valve is open in a normal state, and operates normally to close the valve upon receiving a closing signal from the electronic control unit (not shown) during braking. Solenoid valve of 'NO type'). At this time, the control valve 340 is applied to the solenoid valve of the NO type to release the pressure of the simulation chamber 312 in the event of a system failure.

Then, the operation of the brake system having the above configuration, that is, the case of emergency braking due to normal braking and failure of the system will be described.

First, the case where the brake system is normally operated will be described.

When the driver presses the brake pedal 1, the push rod 2 connected to the brake pedal 1 moves to the left side, and at the same time, the plunger 320, which is in contact with the push rod 2, also moves to the left side. At this time, as the sensor 101 detects this, the electronic control unit drives the motor 110 through it. The motor 110 generates a rotational force in accordance with the rotation of the rotor 112, the ball nut 123 installed in the center of the rotor 112 rotates together to transmit the rotational force to the screw 121. That is, the screw 121 linearly moves to apply a pressure to the master cylinder 210 in contact with the screw 121 to form a braking hydraulic pressure.

On the other hand, there is a gap between the pressing rod 321 disposed in the hollow portion 125 of the screw 121, that is, the end of the plunger 320 and the master cylinder 210, the driver's step force is the master cylinder Is not passed directly to 210. That is, even if the plunger 320 is moved, the piston of the screw 121 and the master cylinder 210 is moved by the distance so that the play between the plunger 320 and the master cylinder 210 is kept constant.

The braking hydraulic pressure generated in the master cylinder 210 is supplied to the inside of the wheel cylinder 240 through the hydraulic pipe 214 through the hydraulic control device 230, the supplied braking hydraulic pressure is installed in the wheel cylinder 240 A braking force is obtained by moving the pad (not shown) to press the disk (not shown).

In addition, during braking, the NO type control valve 340 disposed in the flow path connecting the simulation chamber 312 and the reservoir 220 is blocked when the plunger 320 moves according to the stepping force of the brake pedal 1, and the simulation chamber ( The pressure of 312 is transmitted to the pedal simulator 330 such that a pressure corresponding to the reaction force spring 333 load for which the reaction force piston 332 moves and supports the reaction force piston 332 is created in the simulation chamber 312 so as to be suitable for the driver. Provide a feeling of pedal.

On the other hand, since the operation is performed in the reverse order of the above description when the braking force is released, detailed description thereof will be omitted.

Next, look at the case of emergency braking when the brake system according to the present invention failure.

When the brake system is urgently braked, that is, when the motor 110, the sensor 101, and the control valve 340 are not operated, the driver pushes the pedal 1 and the push rod connected to the pedal 1 is pressed. (2) and the plunger 320 advance to the left. At this time, since the NO type control valve 340 is open and no pressure change occurs in the simulation chamber 312, the clearance between the plunger 320 and the master cylinder 210 is not maintained, and the plunger 320 is directly connected to the master cylinder. A brake force is generated by contacting the piston of 210 to pressurize the piston to create pressure in the master cylinder 210.

As a result, the brake system according to the present invention can effectively transmit the power of the brake pedal 1 to the master cylinder 210 of the hydraulic unit 200 using the motor 110, regardless of the operation of the engine, the master Since the driver's pedaling feeling can be maintained regardless of the pressure change of the cylinder 210, various active control can be supported.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

100: power unit 101: sensor
110: motor 120: ball screw member
121: screw 123: ball nut
200: hydraulic unit 210: master cylinder
220: reservoir 230: hydraulic control device
240: wheel cylinder 300: simulator
310: chamber housing 320: plunger
330: pedal simulator 340: control valve

Claims (9)

A driver for outputting an electric signal when the driver operates the brake pedal to operate the motor and converting the rotational motion of the motor into a linear motion;
A hydraulic unit for braking the wheel with the force generated by the rear force unit; And
And a simulator unit provided to provide reaction force according to the pedal force of the brake pedal. The method of claim 1,
The hydraulic pressure unit includes:
The master cylinder for generating the hydraulic pressure by the pressure according to the linear movement of the power unit, the reservoir coupled to the upper portion of the master cylinder for storing oil, and the hydraulic cylinder connected to the master cylinder and the hydraulic pipe to transfer the braking hydraulic pressure to each wheel cylinder And a hydraulic control device for controlling the brake system. The method of claim 2,
The power unit,
A sensor for detecting an operation of the brake pedal;
A motor having a rotor and a stator for generating a rotational force by an electrical signal of the sensor;
A ball screw member consisting of a screw and a ball nut for converting the rotational motion into a linear motion; And
And an electronic control unit which receives the braking intention according to the driver's effort through the sensor and controls the motor.
The ball nut is installed to rotate with the rotor to linearly move the screw,
And the screw is in contact with the master cylinder and compresses the master cylinder according to the linear motion and has a hollow portion along the longitudinal direction. The method of claim 3,
The simulator unit,
A chamber housing provided at a hollow portion of the screw and having a simulation chamber therein and open at one side to be connected to a brake pedal;
A plunger disposed coaxially with the master cylinder to be advanced by the driver's stepping force and provided in the chamber housing, and a part of which is disposed in the hollow portion of the screw through the chamber housing; And
And a pedal simulator connected to the simulation chamber and a flow path to provide a reaction force to the brake pedal. 5. The method of claim 4,
And a control valve disposed in a flow path connecting the simulation chamber and the reservoir to control oil flowing between the simulation chamber and the reservoir. The method of claim 5,
The control valve is a shut-off valve, the brake system, characterized in that the normal open type solenoid valve which is open in the normal state, but operates to close the valve upon receiving a closing signal. 5. The method of claim 4,
And a spring for returning the plunger to the simulation chamber. 5. The method of claim 4,
Brake system characterized in that it has a constant clearance between the master cylinder and the end of the plunger located in the hollow portion of the screw. 9. The method of claim 8,
And the plunger moves at a distance spaced apart from the master cylinder during abnormal operation of the brake system and then mechanically contacts the master cylinder to transfer the force applied to the plunger.

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