KR102567761B1 - Electric brake system - Google Patents

Abstract

An electronic brake system is disclosed. An electronic brake system according to an embodiment of the present invention includes a reservoir in which braking fluid is stored, a master chamber, a master piston provided in the master chamber and displaceable by a brake pedal, first and second simulation chambers, and a second simulation chamber. 1 a reaction piston provided in the simulation chamber and provided to be displaceable by the hydraulic pressure of the braking fluid accommodated in the master chamber, a damping piston provided in the second simulation chamber and provided to be displaceable by displacement of the reaction force piston, and a reaction piston An integrated master cylinder having an elastic member disposed between the damping pistons, a reservoir passage that communicates the integrated master cylinder and the reservoir, and an electrical signal output in response to the displacement of the brake pedal to operate the hydraulic piston to generate hydraulic pressure, the cylinder A hydraulic pressure supply device including a first pressure chamber provided on one side of a hydraulic piston movably accommodated in the block and connected to one or more wheel cylinders and a second pressure chamber provided on the other side of the hydraulic piston and connected to one or more wheel cylinders, and A hydraulic control unit including a first hydraulic circuit for controlling the hydraulic pressure transmitted to the two wheel cylinders and a second hydraulic circuit for controlling the hydraulic pressure transmitted to the other two wheel cylinders may be provided.

Description

Electronic brake system {Electric brake system}

The present invention relates to an electronic brake system, and more particularly, to an electronic brake system that generates a braking force using an electrical signal corresponding to a displacement of a brake pedal.

A brake system for braking is essentially installed in a vehicle. Recently, various types of systems for obtaining stronger and more stable braking force have been proposed.

An example of a brake system is an anti-lock brake system (ABS: Anti-Lock Brake System) that prevents slipping of wheels during braking, and a brake traction control system (BTCS: Brake Traction Control System), and an Electronic Stability Control System (ESC) that stably maintains the driving state of the vehicle by controlling brake hydraulic pressure by combining an anti-lock brake system and traction control.

In the conventional brake system, when the driver presses the brake pedal, the mechanically connected booster is used to supply the hydraulic pressure required for braking to the wheel cylinder. An electronic brake system including a hydraulic pressure supply device for receiving a braking will as an electrical signal and supplying hydraulic pressure required for braking to a wheel cylinder is widely used.

EP 2 520 473 A1 (Honda Motor Co., Ltd.) 2012. 11. 7.

The present embodiment intends to provide an electronic brake system capable of reducing the number of parts and reducing the weight of a product by integrating a master cylinder and a simulation device into one.

The present embodiment is intended to provide an electronic brake system capable of effectively implementing braking in various operating situations.

The present embodiment is intended to provide an electronic brake system capable of stably generating high-pressure braking pressure.

The present embodiment is intended to provide an electronic brake system with improved performance and operational reliability.

The present embodiment aims to provide an electronic brake system with improved product durability by reducing the load applied to the component elements.

The present embodiment is intended to provide an electronic brake system capable of reducing manufacturing costs while improving assembly and productivity of the product.

According to one aspect of the present invention, a reservoir for storing braking fluid, a master chamber, a master piston provided in the master chamber and displaceable by a brake pedal, first and second simulation chambers, and the first A reaction force piston provided in the simulation chamber and provided to be displaceable by the hydraulic pressure of the braking fluid accommodated in the master chamber, a damping piston provided in the second simulation chamber and provided to be displaceable by displacement of the reaction force piston, An integrated master cylinder having an elastic member disposed between the reaction force piston and the damping piston, a reservoir passage communicating the integrated master cylinder and the reservoir, and a hydraulic piston operated by an electrical signal output in response to displacement of the brake pedal. While generating hydraulic pressure, a first pressure chamber provided on one side of the hydraulic piston movably accommodated in the cylinder block and connected to one or more wheel cylinders and a second pressure chamber provided on the other side of the hydraulic piston and connected to one or more wheel cylinders Provided including a hydraulic pressure supply device including a chamber and a hydraulic control unit having a first hydraulic circuit for controlling the hydraulic pressure transmitted to two wheel cylinders and a second hydraulic circuit for controlling the hydraulic pressure transmitted to the other two wheel cylinders It can be.

The integrated master cylinder may further include a simulation passage that communicates the first simulation chamber and the second simulation chamber, and a simulator valve provided in the simulation passage to control a flow of the braking fluid.

The integrated master cylinder may further include a reaction spring provided in the second simulation chamber and elastically supporting the damping piston.

The reservoir flow path includes a first reservoir flow path that communicates the master chamber and the reservoir, and a second reservoir flow path that communicates the first simulation chamber and the reservoir, and is provided in the first reservoir flow path from the reservoir to the master chamber. A reservoir check valve allowing only the flow of the braking fluid toward the chamber and a diagnostic valve provided in the second reservoir passage to control the flow of the braking fluid in both directions may be provided.

The hydraulic control unit includes a first hydraulic oil passage communicating with the first pressure chamber, second and third hydraulic oil passages diverging from the first hydraulic oil passage and connected to the first and second hydraulic circuits, respectively; 2 a fourth hydraulic oil passage communicating with the pressure chamber and connected to the second hydraulic oil passage, a fifth hydraulic oil passage connecting the second hydraulic oil passage and the third hydraulic oil passage, and the second hydraulic oil passage and the fifth hydraulic oil passage A sixth hydraulic oil passage connecting furnaces, a seventh hydraulic oil passage communicating with the second pressure chamber and connected to the third hydraulic oil passage, and a first control valve provided in the second hydraulic oil passage to control the flow of braking fluid And, a second control valve provided in the third hydraulic oil passage to control the flow of braking fluid, a third control valve provided in the fourth hydraulic oil passage to control the flow of braking fluid, and the third control valve on the fifth hydraulic oil passage 6 A fourth control valve provided between a point to which the hydraulic oil path is connected and a point to which the second hydraulic oil path is connected, and between a point to which the sixth hydraulic oil path is connected and a point to which the third hydraulic oil path is connected on the fifth hydraulic oil path A fifth control valve provided, a sixth control valve provided in the sixth hydraulic oil passage, and a seventh control valve provided in the seventh hydraulic oil passage may be provided.

The third and sixth control valves are provided as solenoid valves that control the flow of braking fluid in both directions, and the first control valve is provided with the flow of braking fluid in the direction from the first pressure chamber to the first hydraulic circuit. the second control valve is provided as a check valve allowing only the flow of braking fluid in a direction from the first pressure chamber to the second hydraulic circuit, and the fourth control valve is It is provided as a check valve that allows only the flow of braking fluid in a direction from the second hydraulic oil passage to a point where the sixth hydraulic oil passage is connected, and the fifth control valve is a point where the sixth hydraulic oil passage is connected from the third hydraulic oil passage. It is provided as a check valve allowing only the flow of braking fluid in the direction toward the second pressure chamber, and the eighth control valve is provided as a check valve allowing only the flow of braking fluid in the direction from the second pressure chamber to the second hydraulic circuit. It can be.

A pedal displacement sensor that detects displacement of the brake pedal and an electronic control unit that controls valves based on hydraulic pressure information and displacement information of the brake pedal, wherein the electronic control unit controls the pedal displacement sensor to operate on the brake pedal. When the displacement is sensed, the sixth control valve may be controlled to open.

The electronic control unit may further include a flow path pressure sensor for sensing a hydraulic pressure of at least one of the first hydraulic circuit and the second hydraulic circuit, and the electronic control unit may detect the hydraulic pressure when the hydraulic pressure detected by the flow path pressure sensor is higher than a preset pressure level. A control may be performed to supply at least a portion of the braking fluid discharged from the first pressure chamber to the second pressure chamber by opening the third control valve.

A first backup passage connecting the master chamber and the first hydraulic circuit, a second backup passage connecting the simulation chamber and the second hydraulic circuit, a first cut valve selectively opening and closing the first backup passage, It further includes a second cut valve that selectively opens and closes a second backup passage, and the first hydraulic circuit includes first and second inlet valves that respectively control hydraulic pressure supplied to the first and second wheel cylinders; and first and second outlet valves respectively controlling hydraulic pressure discharged from the second wheel cylinder to the reservoir, and the second hydraulic circuit includes a third hydraulic circuit controlling hydraulic pressure supplied to the third and fourth wheel cylinders, respectively. and a fourth inlet valve and a third outlet valve respectively controlling the hydraulic pressure discharged from the third wheel cylinder to the reservoir, wherein the second backup passage is a fourth inlet valve of the simulation chamber and the second hydraulic circuit. It may be provided to connect the downstream side of.

A first dump passage connecting the first pressure chamber and the reservoir, a second dump passage connecting the second pressure chamber and the reservoir, and provided in the first dump passage control the flow of the braking fluid from the reservoir. A first dump valve provided as a check valve allowing only the flow of braking fluid in the direction toward the first pressure chamber, provided in the second dump passage to control the flow of braking fluid, and between the reservoir and the second pressure chamber A second dump valve provided as a solenoid valve for controlling the flow of braking fluid in both directions, provided in a bypass flow path connected in parallel to the second dump valve on the second dump flow path, from the reservoir to the second pressure chamber A third dump valve provided as a check valve allowing only the flow of the braking fluid in the direction toward the direction may be further included.

The electronic brake system according to the present embodiment can reduce the number of parts and reduce the weight of the product by using the integrated master cylinder.

The electronic brake system according to an embodiment of the present invention can stably and effectively implement braking in various operating situations of a vehicle.

The electronic brake system according to an embodiment of the present invention can stably generate high-pressure braking pressure.

The electronic brake system according to the embodiment of the present invention can improve product performance and operation reliability.

The electronic brake system according to an embodiment of the present invention can stably provide braking pressure even in the event of component failure or leakage of braking fluid.

The electronic brake system according to an embodiment of the present invention has an effect of improving durability of a product by reducing a load applied to a component element.

The electronic brake system according to an embodiment of the present invention can improve assembly and productivity of a product, while reducing manufacturing cost of the product.

1 is a hydraulic circuit diagram showing an electronic brake system according to an embodiment of the present invention.
2 is an enlarged view showing an integrated master cylinder, a reservoir, and a reservoir passage of an electronic brake system according to an embodiment of the present invention.
3 is an enlarged view showing a hydraulic pressure providing unit of an electronic brake system according to an embodiment of the present invention.
4 is a hydraulic circuit diagram showing a state in which an electronic brake system according to an embodiment of the present invention provides braking pressure in a low pressure mode.
5 is a hydraulic circuit diagram showing a state in which an electronic brake system according to an embodiment of the present invention provides braking pressure in a high pressure mode.
6 is a hydraulic circuit diagram showing a state in which the electronic brake system according to an embodiment of the present invention releases the braking pressure in the high pressure mode.
7 is a hydraulic circuit diagram showing a state in which the electronic brake system according to an embodiment of the present invention releases the braking pressure in the low pressure mode.
8 is a hydraulic circuit diagram showing a state (fallback mode) in which the electronic brake system according to an embodiment of the present invention is abnormally started.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention may be embodied in other forms without being limited to only the embodiments presented herein. In the drawings, in order to clarify the present invention, illustration of parts irrelevant to the description may be omitted, and the size of components may be slightly exaggerated to aid understanding.

1 is a hydraulic circuit diagram showing an electronic brake system 1 according to an embodiment of the present invention.

Referring to FIG. 1, the electronic brake system 1 according to an embodiment of the present invention pressurizes and discharges braking fluid such as brake oil accommodated inside by the pedal force of the brake pedal, and reacts according to the pedal force of the brake pedal 10. An integrated master cylinder 20 that provides a driver, a reservoir 30 that communicates with the integrated master cylinder 20 and stores braking fluid therein, and the hydraulic pressure of the braking fluid is transmitted to each wheel (RR, RL, FR) , FL) by the wheel cylinder 40 that performs braking and the pedal displacement sensor 11 that detects the displacement of the brake pedal 10, the driver's will to brake is transmitted as an electrical signal, and the braking fluid is mechanically operated. The hydraulic pressure supply device 100 that generates hydraulic pressure, the hydraulic control unit 200 that controls the hydraulic pressure transmitted to the wheel cylinder 40, and the hydraulic pressure supply device and various valves are controlled based on hydraulic pressure information and pedal displacement information. It may include an electronic control unit (ECU, not shown) that does.

The integrated master cylinder 20 is provided with a master chamber 21a and simulation chambers 22a and 23a to pressurize and discharge the braking fluid inside and at the same time provide a reaction force to the pedal force of the brake pedal 10 to the driver. can

FIG. 2 is an enlarged view showing an integrated master cylinder 20, a reservoir 30, and reservoir passages 61 and 62 of an electronic brake system 1 according to an embodiment of the present invention. Referring to FIG. 2, The integrated master cylinder 20 includes a master chamber 21a, a master piston 21 provided in the master chamber 21a and displaceable by operation of the brake pedal 10, and the master piston 21 elastically. Provided to be displaceable by a restoring spring (not shown), first and second simulation chambers 23a, and the hydraulic pressure of the braking fluid provided in the first simulation chamber 22a and accommodated in the master chamber 21a Between the reaction force piston 22, the damping piston 23 provided in the second simulation chamber 23a and displaceable by the displacement of the reaction force piston 22, and the reaction force piston 22 and the damping piston 23 An elastic member 24 disposed in the second simulation chamber 23a to elastically support the pistons 22 and 23, and a reaction spring 22b provided in the second simulation chamber 23a to elastically support the reaction piston 22 and the damping piston 23 ), a simulation passage 25 communicating the first simulation chamber 22a and the second simulation chamber 23a, and a simulator valve 26 provided in the simulation passage 25.

The master chamber 21a is provided with a master piston 21 connected to the input rod, a reaction piston 22 is provided in the first simulation chamber 22a, and a damping piston 23 is provided in the second simulation chamber 23a. and a reaction spring 24 is provided. The master chamber 21a, the first simulation chamber 22a, and the second simulation chamber 23a may be sequentially formed on the integrated master cylinder 20 along the operating direction of the brake pedal.

In the master chamber 21a, braking fluid may be introduced and discharged through the first hydraulic port 27a and the second hydraulic port 27b, and the first simulation chamber 22a has a third hydraulic port 27c and a second hydraulic port 27c. 4 The braking fluid can be introduced and discharged through the hydraulic port 27d. Also, the braking fluid may be introduced and discharged into the second simulation chamber 23a through the fifth hydraulic port 27e. Specifically, the first hydraulic port 27a may be connected to a first backup oil passage to be described later, and the second hydraulic port 27b may be connected to a first reservoir oil passage 61 to be described later. In addition, the third hydraulic port 27c and the fourth hydraulic port 27d are connected to the simulation oil passage 25, and the fifth hydraulic port 27e is connected to a second backup oil passage 252 and a second reservoir oil passage 62 to be described later. ) can be connected to

Meanwhile, the integrated master cylinder 20 according to an embodiment of the present invention includes a master chamber 21a and a first simulation chamber 22a, thereby ensuring safety in the event of component failure. For example, the master chamber 21a is connected to two wheels among the right front wheel FR, the left front wheel FL, the left rear wheel RL, and the right rear wheel RR of the vehicle, and the first simulation chamber 22a is connected to the other wheels. It can be connected to two wheels, and accordingly, even when one of the master chambers 21a fails, braking of the vehicle can be performed. For example, the master chamber 21a is connected to the first and second wheel cylinders 41 and 42, and the first simulation chamber 22a is connected to the third and fourth wheel cylinders 43 and 44. can

An elastic member (not shown) may be provided between the master piston 21 and the reaction force piston 22 of the integrated master cylinder 20, and a reaction spring between the end of the damping piston 23 and the integrated master cylinder 20. (22b) may be provided. As the driver operates the brake pedal 10 and the displacement changes, the master piston 21 moves, and at this time, the return spring is compressed. Thereafter, when the pressing force of the brake pedal 10 is released, the master piston 21 may return to its original position while the restoring spring expands by the elastic force.

The master chamber 21a may be connected to the reservoir 30 through the first reservoir flow path 61 , and the first simulation chamber 22a may be connected to the reservoir 30 through the second reservoir flow path 62 . A reservoir check valve 65 may be provided in the first reservoir flow path 61 to allow only the flow of the braking fluid from the reservoir 30 toward the master chamber 21a and block the flow of the braking fluid in the opposite direction. In addition, a diagnostic valve 66 provided as a two-way control valve for controlling the flow of the braking fluid delivered through the second reservoir passage 62 may be installed in the second reservoir passage 62, and the diagnosis valve 66 may be provided as a normally closed type solenoid valve that is normally closed and operates so that the valve opens when an electrical signal is received from the electronic control unit. A second backup passage 252 may be branched and provided at a front end of the diagnostic valve 66 on the second reservoir passage 62 . A detailed description of this will be described later.

The integrated master cylinder 20 includes two sealing members 28a and 28b disposed before and after the first reservoir passage 61 connected to the master chamber 21a, and two seal members 28a and 28b disposed before and after the second reservoir passage 62. It may include two sealing members (28c, 28d). The sealing member 28 may be provided in a ring-shaped structure protruding from the inner wall of the integrated master cylinder 20 or the outer circumferential surfaces of the master piston 21, the reaction force piston 22, and the damping piston 23.

The reaction piston 22 is provided to have a certain range of displacement within the first simulation chamber 22a by the hydraulic pressure of the braking fluid pressurized in the master chamber 21a, and the damping piston 23 is It can move along with the movement and pressurize the braking fluid accommodated in the second simulation chamber 23a. The damping piston 23 is provided to pressurize the second simulation chamber 23a, and an elastic member 24 is disposed between the reaction force piston 22 and the damping piston 23, and the elastic member 24 is the reaction force piston 22 and the damping piston 23 may be made of a material such as compressible and expandable rubber according to the displacement. In addition, a reaction spring 22b is provided between the rear of the damping piston 23 (the left side of the damping piston 23 based on the drawing) and the end of the integrated master cylinder 20, so that the damping piston 23 and the reaction piston 22 can be elastically supported.

The simulation passage 25 is provided to communicate the first simulation chamber 22a and the second simulation chamber 23a, and a simulator valve 26 for controlling the flow of the braking fluid is provided in the simulation passage 25. can The simulator valve 26 may be provided as a normal open type solenoid valve that is normally open but closes when an electrical signal is received from the electronic control unit.

In more detail about the pedal simulation operation by the integrated master cylinder 20, when the driver operates the brake pedal 10 and applies a pedal force during normal operation, the first cut provided in the first backup passage 251 to be described later The valve 261 is closed, the simulator valve 26 of the simulation flow path 25 is also closed, and the diagnostic valve 66 of the second reservoir flow path 62 is open. The second simulation chamber 23a is closed as the simulator valve 26 is closed, and the master piston 21 moves according to the displacement of the brake pedal, so that the braking fluid in the master chamber 21a is pressurized, and the hydraulic pressure is the reaction force. Displacement occurs in the reaction force piston 22 while being transmitted to the front surface of the piston 22 (the right side of the reaction force piston based on the drawing). Since the second simulation chamber 23a is closed and the displacement of the damping piston 23 does not occur, the displacement of the reaction force piston 22 compresses the elastic member 24, resulting in elasticity due to the compression of the elastic member 24. A pedal feeling may be provided to the driver by the restoring force. At this time, the braking fluid accommodated in the first simulation chamber 22a is transferred to the reservoir 30 through the second reservoir passage 62 . Then, when the driver releases the pedal force of the brake pedal 10, the reaction force piston 22 and the master piston 21 return to their original positions while the restoring spring (not shown) and the elastic member 24 expand by the elastic restoring force. , the first simulation chamber 22a may be filled with the braking fluid supplied through the second reservoir passage 62 .

As such, since the inside of the first simulation chamber 22a is always filled with braking fluid, friction between the reaction force piston 22 and the damping piston 23 is minimized during pedal simulation operation, so that the durability of the integrated master cylinder 20 is improved. Of course, the inflow of foreign substances from the outside can be blocked.

Meanwhile, when the electronic brake system 1 operates abnormally, that is, the operation of the integrated master cylinder 20 in the fallback mode operating state will be described later with reference to FIG. 10 .

The reaction spring 22b shown in the figure is only an example capable of providing elastic force to the reaction force piston 22 and the damping piston 23, and may be configured in various structures capable of storing the elastic force. For example, it may be made of a material such as rubber or made of various members capable of storing elastic force by having a coil or plate shape.

On the other hand, several reservoirs 30 are shown in the drawing, and each reservoir 30 uses the same reference numeral. These reservoirs 30 may be provided with the same part or different parts.

The hydraulic pressure supply device 100 receives the driver's braking intention as an electrical signal from the pedal displacement sensor 11 that detects the displacement of the brake pedal 10 and generates hydraulic pressure of the braking fluid through mechanical operation.

The hydraulic pressure supply device 100 includes a hydraulic pressure supply unit 110 that provides braking fluid pressure transmitted to wheel cylinders, a motor 120 that generates rotational force by an electrical signal from a pedal displacement sensor 11, and a motor 120 ) It may include a power conversion unit 130 that converts the rotational motion into linear motion and transmits it to the hydraulic pressure providing unit 110. The hydraulic pressure providing unit 110 may be operated not by driving force supplied by the motor 120 but by pressure supplied by the high-pressure accumulator.

3 is an enlarged view showing the hydraulic pressure supply unit of the electronic brake system 1 according to an embodiment of the present invention. Referring to FIG. 3, the hydraulic pressure supply unit 110 is provided with a pressure chamber in which braking fluid is supplied and stored. A cylinder block 111 to do, a hydraulic piston 114 accommodated in the cylinder block 111, and sealing members 115a and 115b provided between the hydraulic piston 114 and the cylinder block 111 to seal the pressure chamber, , It includes a drive shaft 133 that transmits the power output from the power conversion unit 130 to the hydraulic piston 114.

The pressure chamber includes a first pressure chamber 112 located at the front of the hydraulic piston 114 (in the forward direction, in the left direction of the hydraulic piston based on the drawing), and at the rear of the hydraulic piston 114 (in the backward direction, based on the drawing). It may include a second pressure chamber 113 located in the right direction of the hydraulic piston). That is, the first pressure chamber 112 is partitioned by the front end of the cylinder block 111 and the hydraulic piston 114, and is provided so that the volume varies according to the movement of the hydraulic piston 114, and the second pressure chamber 113 Is partitioned by the cylinder block 111 and the rear end of the hydraulic piston 114, and is provided so that the volume varies according to the movement of the hydraulic piston 114.

The first pressure chamber 112 is connected to a first hydraulic oil passage 211 to be described later through a first communication hole 111a formed in the cylinder block 111, and the second pressure chamber 113 is connected to the cylinder block 111 It is connected to a fourth hydraulic oil passage 214 to be described later through a second communication hole 111b formed in ).

The sealing member 115 is a piston sealing member 115a provided between the hydraulic piston 114 and the cylinder block 111 to seal between the first pressure chamber 112 and the second pressure chamber 113, and the drive shaft 133 ) And a drive shaft sealing member 115b provided between the cylinder block 111 and sealing the openings of the second pressure chamber 113 and the cylinder block 111. The hydraulic or negative pressure in the first and second pressure chambers 112 and 13 generated by the forward or backward movement of the hydraulic piston 114 is sealed by the piston sealing member 115a and does not leak to the second pressure chamber 113. The hydraulic pressure or negative pressure of the second pressure chamber 113 generated by the forward or backward movement of the hydraulic piston 114 is transmitted to the first and fourth hydraulic oil passages 211 and 214 without It is sealed by and may not leak to the outside of the cylinder block 111.

The first and second pressure chambers 112 and 113 are connected to the reservoir 30 by first and second dump passages 116 and 117, respectively, and by the first and second dump passages 116 and 117, respectively. The braking fluid supplied from the reservoir 30 may be received and accommodated, or the braking fluid in the first or second pressure chambers 112 and 113 may be delivered to the reservoir 30 . To this end, the first dump passage 116 may be provided in communication with the first pressure chamber 112 through a third communication hole 111c formed in the cylinder block 111 and connected to the reservoir 30. The second dump passage 117 may be provided in communication with the second pressure chamber 113 and connected to the reservoir 30 through the fourth communication hole 111d formed in the cylinder block 111 .

The motor 120 is provided to generate driving force by an electrical signal output from an electronic control unit (ECU). The motor 120 may include a stator 121 and a rotor 122, and may provide power for generating displacement of the hydraulic piston 114 by rotating in a forward or reverse direction through the stator 121. The rotational angular velocity and rotational angle of the motor 120 can be precisely controlled by the motor control sensor MPS. Since the motor 120 is a well-known technology, a detailed description thereof will be omitted.

The power conversion unit 130 is provided to convert the rotational force of the motor 120 into linear motion. The power conversion unit 130 may be provided with a structure including, for example, a worm shaft 131, a worm wheel 132, and a driving shaft 133.

The worm shaft 131 may be integrally formed with the rotating shaft of the motor 120, and a worm may be formed on an outer circumferential surface thereof to be coupled to engage with the worm wheel 132 to rotate the worm wheel 132. The worm wheel 132 is connected to engage with the drive shaft 133 to linearly move the drive shaft 133, and the drive shaft 133 is connected to the hydraulic piston 114, through which the hydraulic piston 114 is connected to the cylinder block It can be moved by sliding within (111).

To explain the above operations again, when the displacement of the brake pedal 10 is detected by the pedal displacement sensor 11, the detected signal is transmitted to the electronic control unit, and the electronic control unit drives the motor 120 to operate the worm shaft (131) is rotated in one direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 via the worm wheel 132, and the hydraulic piston 114 connected to the drive shaft 133 moves forward in the cylinder block 111, causing the first pressure chamber 112 to move forward. can generate hydraulic pressure.

Conversely, when the pedal force of the brake pedal 10 is released, the electronic control unit drives the motor 120 to rotate the worm shaft 131 in the opposite direction. Therefore, the worm wheel 132 also rotates in the opposite direction, and the hydraulic piston 114 connected to the driving shaft 133 moves backward within the cylinder block 111 to generate negative pressure in the first pressure chamber 112 .

The generation of hydraulic pressure and negative pressure in the second pressure chamber 113 can be implemented by operating in the opposite direction from above. That is, when the displacement of the brake pedal 10 is detected by the pedal displacement sensor 11, the detected signal is transmitted to the electronic control unit, and the electronic control unit drives the motor 120 to reverse the worm shaft 131. rotate in the direction The rotational force of the worm shaft 131 is transmitted to the driving shaft 133 via the worm wheel 132, and the hydraulic piston 114 connected to the driving shaft 133 is moved backward in the cylinder block 111 while moving the second pressure chamber 113 can generate hydraulic pressure.

Conversely, when the pedal force of the brake pedal 10 is released, the electronic control unit drives the motor 120 in one direction to rotate the worm shaft 131 in one direction. Therefore, the worm wheel 132 also rotates in the opposite direction, and the hydraulic piston 114 connected to the drive shaft 133 moves forward within the cylinder block 111, thereby generating negative pressure in the second pressure chamber 113.

As such, the hydraulic pressure supply device 100 generates hydraulic pressure or negative pressure in the first pressure chamber 112 and the second pressure chamber 113 according to the rotation direction of the worm shaft 131 by the motor 120 driving. It can be determined by controlling the valves whether braking is implemented by transmitting hydraulic pressure or braking is released using negative pressure. A detailed description of this will be described later.

On the other hand, although not shown in the drawings, the power conversion unit 130 may be composed of a ball screw nut assembly. For example, it consists of a screw formed integrally with the rotating shaft of the motor 120 or connected to rotate together with the rotating shaft of the motor 120, and a ball nut that is screwed with the screw in a state where rotation is limited and moves linearly according to the rotation of the screw. Since the structure of such a ball screw nut assembly is a well-known technology, detailed description thereof will be omitted. In addition, the power conversion unit 130 according to an embodiment of the present invention is not limited to any one structure as long as it can convert rotational motion into linear motion, and it should be understood the same even when it is composed of various structures and types of devices. will be.

The hydraulic control unit 200 may be provided to control the hydraulic pressure transmitted to the wheel cylinder, and the electronic control unit (ECU) is provided to control the hydraulic pressure supply device 100 and various valves based on hydraulic pressure information and pedal displacement information. do.

The hydraulic control unit 200 includes a first hydraulic circuit 201 and third and fourth wheel cylinders that control the flow of hydraulic pressure transmitted to the first and second wheel cylinders 41 and 42 among the four wheel cylinders ( 43, 44) may be provided with a second hydraulic circuit 202 that controls the flow of hydraulic pressure, and multiple hydraulic pressures transmitted from the integrated master cylinder 20 and the hydraulic pressure supply device 100 to the wheel cylinders are controlled. of the flow path and valve.

Hereinafter, with reference to FIG. 1 again, the hydraulic control unit 200 will be described.

Referring to FIG. 1 , a first hydraulic oil path 211 is provided to connect the first pressure chamber 112 and the first and second hydraulic circuits 201 and 202, and the first hydraulic oil path 211 is A second hydraulic oil passage 212 communicating with the hydraulic circuit 201 and a third hydraulic oil passage 213 communicating with the second hydraulic circuit 202 may be provided. As a result, the hydraulic pressure generated in the first pressure chamber 112 by the advancement of the hydraulic piston 114 flows through the second hydraulic oil passage 212 and the third hydraulic oil passage 213 to the first hydraulic circuit 201 and the second hydraulic circuit. (202).

A first control valve 231 may be provided in the second hydraulic oil passage 212 to control the flow of braking fluid, and the first control valve 231 is connected to the first hydraulic circuit 201 from the first pressure chamber 112. ) may be provided with a check valve that allows only the flow of braking fluid in a direction toward the direction and blocks the flow of braking fluid in the opposite direction. That is, the first control valve 231 allows the hydraulic pressure generated in the first pressure chamber 112 to be transferred to the first hydraulic circuit 201, while the hydraulic pressure of the first hydraulic circuit 201 is transmitted to the second hydraulic oil path ( 212) to prevent leakage into the first pressure chamber 112.

A second control valve 232 may be provided in the third hydraulic oil passage 213 to control the flow of the braking fluid. The second control valve 232 may be provided as a check valve that allows only the flow of braking fluid in a direction from the first pressure chamber 112 toward the second hydraulic circuit 202 and blocks the flow of braking fluid in the opposite direction. . That is, the second control valve 232 allows the hydraulic pressure generated in the first pressure chamber 112 to be transmitted to the second hydraulic circuit 202, while the hydraulic pressure of the second hydraulic circuit 202 is transmitted to the third hydraulic oil path ( 213) to prevent leakage into the first pressure chamber 112.

The fourth hydraulic oil passage 214 may be provided to connect the second pressure chamber 113 and the first hydraulic circuit 201, and the fifth hydraulic oil passage 215 has one end on the second hydraulic oil passage 212. 1 connected to the rear end of the control valve 231 and the other end connected to the rear end of the second control valve 232 of the third hydraulic oil passage 213 to connect the second hydraulic oil passage 212 and the third hydraulic oil passage 213 can be provided. The sixth hydraulic oil passage 216 may be provided to connect the second hydraulic oil passage 212 and the fifth hydraulic oil passage 215, and for this purpose, both ends of the sixth hydraulic oil passage 216 are connected to the second hydraulic oil passage 212. It may be provided in communication with the front end of the first control valve 231 and the fifth hydraulic oil passage 215 . In addition, the seventh hydraulic oil passage 217 is branched from the front end of the third control valve 233 on the fourth hydraulic oil passage 214 to connect the second pressure chamber 113 and the second hydraulic circuit 202, and the third hydraulic oil passage 217 It may be provided by joining the rear end of the second control valve 232 on the furnace 213.

A third control valve 233 for controlling the flow of braking fluid may be provided in the fourth hydraulic oil passage 214 .

The third control valve 233 may be provided as a two-way control valve that controls the flow of the braking fluid delivered along the fourth hydraulic oil passage 214 communicating with the second pressure chamber 113 . The fourth control valve 224 may be provided as a normally closed type solenoid valve that is normally closed and operates to open when an electrical signal is received from the electronic control unit.

Fourth and fifth control valves 234 and 235 for controlling the flow of the braking fluid may be provided in the fifth hydraulic oil passage 215 .

The fourth control valve 234 may be provided between a point where the sixth hydraulic oil passage 216 is connected and a point where the second hydraulic oil passage 212 is connected on the fifth hydraulic oil passage 215, and the fifth control valve 235 ) may be provided between a point where the sixth hydraulic oil passage 216 is connected and a point where the third hydraulic oil passage 213 is connected on the fifth hydraulic oil passage 215 . The fourth control valve 234 may be provided as a check valve that allows only the flow of braking fluid in a direction from the second hydraulic oil passage 212 to the point where the sixth hydraulic oil passage 216 is connected, and the fifth control valve ( 235) may be provided as a check valve that allows only the flow of braking fluid in a direction from the third hydraulic oil passage 213 to the point where the sixth hydraulic oil passage 216 is connected.

A sixth control valve 236 may be provided in the sixth hydraulic oil passage 216 to control the flow of the braking fluid.

The sixth control valve 236 may be provided as a two-way control valve that controls the flow of the braking fluid delivered along the sixth hydraulic oil passage 216 . The sixth control valve 236 may be provided as a normally closed type solenoid valve that is normally closed and operates to open when an electrical signal is received from the electronic control unit.

A seventh control valve 237 may be provided in the seventh hydraulic oil passage 217 to control the flow of the braking fluid.

The seventh control valve 237 may be provided as a check valve that allows only the flow of braking fluid in a direction from the second pressure chamber 113 toward the second hydraulic circuit 202 and blocks the flow of braking fluid in the opposite direction. . That is, the seventh control valve 237 allows the hydraulic pressure generated in the second pressure chamber 113 to be transferred to the second hydraulic circuit 202, while the hydraulic pressure of the second hydraulic circuit 202 is transmitted to the seventh hydraulic oil path ( 217), leakage into the second pressure chamber 113 can be prevented.

Hereinafter, the first hydraulic circuit 201 and the second hydraulic circuit 202 of the hydraulic control unit 200 will be described.

The first hydraulic circuit 201 controls the hydraulic pressure of the first and second wheel cylinders 41 and 42, which are two wheel cylinders among the four wheels RR, RL, FR, and FL, and the second hydraulic circuit 202 ) can control the hydraulic pressure of the third and fourth wheel cylinders 43 and 44, which are the other two wheel cylinders.

The first hydraulic circuit 201 is connected to the first hydraulic oil passage 211 and the second hydraulic oil passage 212 to receive hydraulic pressure from the hydraulic pressure supply device 100, and the second hydraulic oil passage 212 is connected to the first wheel cylinder. It may be provided by branching into two passages connected to the second wheel cylinder. Similarly, the second hydraulic circuit 202 is connected to the first hydraulic oil passage 211 and the third hydraulic oil passage 213 to receive hydraulic pressure from the hydraulic pressure supply device 100, and the third hydraulic oil passage 213 is connected to the third hydraulic oil passage 213. It may be provided by branching into two passages connected to the wheel cylinder 43 and the fourth wheel cylinder 44.

The first and second hydraulic circuits 201 and 202 include first to fourth inlet valves 221 (221a, 221b, 221c) to control the flow and hydraulic pressure of the braking fluid delivered to the first to fourth wheel cylinders 40 , 221d) may be respectively provided. The first to fourth inlet valves 221 are disposed on the upstream side of the first to fourth wheel cylinders 40, respectively, and are normally open, but operate to close the valves when an electrical signal is received from the electronic control unit. It may be provided as a solenoid valve of a normal open type.

The first and second hydraulic circuits 201 and 202 are first to fourth check valves 223a, 223b, and 223c that are connected in parallel to the first to fourth inlet valves 221a, 221b, 221c, and 221d. , 223d). The check valves 223a, 223b, 223c, and 223d are bypasses connecting the front and rear sides of the first to fourth inlet valves 221a, 221b, 221c, and 221d on the first and second hydraulic circuits 201 and 202. It may be provided in the flow path, and may be provided to allow only the flow of braking fluid from each wheel cylinder to the hydraulic pressure providing unit 110 and block the flow of braking fluid from the hydraulic pressure providing unit 110 to the wheel cylinder. . The first to fourth check valves 223a, 223b, 223c, and 223d can quickly release the hydraulic pressure of the braking fluid applied to the first to fourth wheel cylinders 40, and the first to fourth inlet valves 221a, Even when 221b, 221c, and 221d) do not operate normally, the hydraulic pressure of the braking fluid applied to the wheel cylinder can flow into the hydraulic pressure providing unit 110.

The first hydraulic circuit 201 may include first and second outlet valves 222a and 222b connected to the reservoir 30 to improve performance when braking of the first and second wheel cylinders 41 and 42 is released. can In addition, the second hydraulic circuit 202 may include a third outlet valve 222c connected to the reservoir 30 to improve performance when the braking of the third wheel cylinder 43 is released. The first to third outlet valves 222 are connected to the first to third wheel cylinders 43, respectively, and control the flow of braking fluid from the wheel cylinders. That is, the first to third outlet valves 222 sense the braking pressure of the first to third wheel cylinders 43 and are selectively opened when decompression braking is required to control depressurization of the wheel cylinders. The first to third outlet valves 222 may be provided as normally closed type solenoid valves that are normally closed but open when an electrical signal is received from the electronic control unit.

Meanwhile, a second backup passage 252 to be described later is provided at the rear end or downstream of the fourth inlet valve on the fourth wheel cylinder 44 side, and the second backup passage 252 controls the flow of the braking fluid. 2 cut valves 262 may be provided. A detailed description of this will be described later.

First and second dump valves 241 and 242 for controlling the flow of the braking fluid may be provided in the first and second dump passages 116 and 117, respectively. Referring to FIG. 1 again, the first dump valve 241 is provided as a check valve that allows only the flow of braking fluid from the reservoir 30 to the first pressure chamber 112 and blocks the flow of braking fluid in the opposite direction. It can be. That is, the first dump valve 241 allows the braking fluid to flow from the reservoir 30 to the first pressure chamber 112, but does not allow the braking fluid to flow from the first pressure chamber 112 to the reservoir 30. can block The second dump valve 242 may be provided as a two-way control valve that controls the flow of the braking fluid between the second pressure chamber 113 and the reservoir 30 . The second dump valve 242 may be provided as a normal open type solenoid valve that is normally open but closes when an electrical signal is received from the electronic control unit.

In addition, a bypass passage connected in parallel to the second dump valve 242 may be provided in the second dump passage 117 . Specifically, the bypass passage may be provided by bypassing and connecting the front and rear of the second dump valve 242 on the second dump passage 117, and the second pressure chamber 113 and the reservoir ( 30) may be provided with a third dump valve 243 that controls the flow of braking fluid between them. The third dump valve 243 may be provided as a check valve that allows only the flow of braking fluid from the reservoir 30 toward the second pressure chamber 113 and blocks the flow of braking fluid in the opposite direction. That is, the third dump valve 243 allows the braking fluid to flow from the reservoir 30 to the second pressure chamber 113, but does not allow the braking fluid to flow from the second pressure chamber 113 to the reservoir 30. can block

The hydraulic pressure providing unit 110 of the electronic brake system 1 according to the embodiment of the present invention may operate in a double-acting manner.

Specifically, the hydraulic pressure generated in the first pressure chamber 112 while the hydraulic piston 114 moves forward is transmitted to the first hydraulic circuit 201 through the first hydraulic oil passage 211 and the second hydraulic oil passage 212, It is possible to implement braking of the first and second wheel cylinders 41 and 42, and is transferred to the second hydraulic circuit 202 through the first hydraulic oil passage 211 and the third hydraulic oil passage 213, Braking of the four wheel cylinders 43 and 44 can be implemented.

Similarly, hydraulic pressure generated in the second pressure chamber 113 while the hydraulic piston 114 moves backward is transferred to the first hydraulic circuit 201 through the fourth hydraulic oil passage 214 and the second hydraulic oil passage 212, It is possible to implement braking of the first and second wheel cylinders 41 and 42, and is transmitted to the second hydraulic circuit 202 through the seventh hydraulic oil passage 217 and the third hydraulic oil passage 213 in the same way, and the third and fourth hydraulic oil passages 213 are transmitted. Braking of the fourth wheel cylinders 43 and 44 can be implemented.

In addition, while the hydraulic piston 114 moves backward, the negative pressure generated in the first pressure chamber 112 sucks the braking fluid of the first and second wheel cylinders 41 and 42 and flows from the first hydraulic circuit 201 to the second pressure chamber. The braking fluid may be returned to the first pressure chamber 112 through the hydraulic oil passage 212, the fifth hydraulic oil passage 215, and the sixth hydraulic oil passage 216, and the third and fourth wheel cylinders 43 and 44 ) by sucking the braking fluid from the second hydraulic circuit 202 to the first pressure chamber 112 through the third hydraulic oil passage 213, the fifth hydraulic oil passage 215, and the sixth hydraulic oil passage 216. can be returned.

In addition, the electronic brake system 1 according to an embodiment of the present invention can implement braking by directly supplying the braking fluid discharged from the integrated master cylinder 20 to the wheel cylinder when normal operation is impossible due to a device failure. It may include first and second backup flow paths (251, 252). A mode in which the hydraulic pressure of the integrated master cylinder 20 is directly transmitted to the wheel cylinder is referred to as a fallback mode.

The first backup passage 251 is provided to connect the master chamber 21a of the integrated master cylinder 20 and the first hydraulic circuit 201, and the second backup passage 252 connects the first hydraulic circuit 201 to the integrated master cylinder 20. 1 may be provided to connect the simulation chamber 22a and the second hydraulic circuit 202. Specifically, the first backup passage 251 may be connected to join the rear ends of the first or second inlet valves 221a and 221b on the first hydraulic circuit 201, and the second backup passage 252 may be connected to the second It may be connected to join the rear end of the fourth inlet valve 221d on the hydraulic circuit 202.

A first cut valve 261 for controlling the flow of braking fluid is provided in the first backup passage 251, and a second cut valve 262 for controlling the flow of braking fluid is provided in the second backup passage 252. It can be. The first and second cut valves 261 and 262 are normally open, but may be provided as normal open type solenoid valves that operate to close when a closing signal is received from the electronic control unit. .

Accordingly, when the first and second cut valves 261 and 262 are closed, the hydraulic pressure provided from the hydraulic pressure supply device 100 can be supplied to the wheel cylinder through the first and second hydraulic circuits 201 and 202. And, when the first and second cut valves 261 and 262 are opened, the hydraulic pressure provided from the integrated master cylinder 20 can be supplied to the wheel cylinders through the first and second backup passages 251 and 252. there is.

The electronic brake system 1 according to an embodiment of the present invention may include a flow pressure sensor PS1 for sensing the hydraulic pressure of at least one of the first hydraulic circuit 201 and the second hydraulic circuit 202 . The flow pressure sensor PS1 is provided at the front end of the inlet valve 221 of at least one of the first hydraulic circuit 201 and the second hydraulic circuit 202, and the first hydraulic circuit 201 and the second hydraulic circuit 202 It is possible to detect the hydraulic pressure of the braking fluid applied to the In the drawing, the flow pressure sensor PS1 is shown as being provided in the second hydraulic circuit 202, but is not limited to this structure, and if it can detect the hydraulic pressure applied to the hydraulic circuits 201 and 202, one Or it includes a case where it is provided in various numbers.

Hereinafter, the operation of the electronic brake system 1 according to an embodiment of the present invention will be described.

In the electronic brake system 1 according to the embodiment of the present invention, the hydraulic pressure supply device 100 can be used by dividing it into a low pressure mode and a high pressure mode. The low pressure mode and the high pressure mode can be changed by changing the operation of the hydraulic control unit 200 . The hydraulic pressure supply device 100 can provide high hydraulic pressure without increasing the output of the motor 120 by using the high-pressure mode, and furthermore, the load applied to the motor 120 can be reduced. As a result, it is possible to secure a stable braking force while reducing the cost and weight of the brake system, and improve durability and operational reliability of the device.

When the hydraulic piston 114 moves forward by driving the motor 120, hydraulic pressure is generated in the first pressure chamber 112. As the hydraulic piston 114 moves forward from the initial position, that is, as the operating stroke of the hydraulic piston 114 increases, the supply amount of the braking fluid transferred from the first pressure chamber 112 to the wheel cylinder increases, and the braking pressure increases. However, since the hydraulic piston 114 has an effective stroke, the maximum pressure due to the advancement of the hydraulic piston 114 exists.

At this time, the maximum pressure of the low pressure mode is smaller than the maximum pressure of the high pressure mode. However, in the high pressure mode, the pressure increase rate per stroke of the hydraulic piston 114 is small compared to the low pressure mode. This is because not all of the braking fluid discharged from the first pressure chamber 112 is transferred to the wheel cylinder, but some of it is transferred to the second pressure chamber 113 . This will be described later with reference to FIG. 5 .

Therefore, a low pressure mode with a large pressure increase rate per stroke can be used in the early stage of braking where braking response is important, and a high pressure mode with a large maximum pressure can be used in the late stage of braking where the maximum braking force is important.

4 is a hydraulic circuit diagram showing a state in which the hydraulic piston 114 of the electronic brake system 1 according to an embodiment of the present invention provides braking pressure in a low pressure mode while moving forward, and FIG. 5 is a diagram according to an embodiment of the present invention It is a hydraulic circuit diagram showing a state in which the hydraulic piston 114 of the electronic brake system 1 moves forward while providing braking pressure in the high pressure mode.

4, when the driver steps on the brake pedal 10 at the beginning of braking, the motor 120 operates to rotate in one direction, and the rotational force of the motor 120 is transferred to the hydraulic pressure supply unit by the power transmission unit 130. 110, while the hydraulic piston 114 of the hydraulic pressure providing unit 110 moves forward, generating hydraulic pressure in the first pressure chamber 112. The hydraulic pressure discharged from the first pressure chamber 112 is transmitted to the first to fourth wheel cylinders 40 respectively provided on the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to provide braking force. causes

Specifically, the hydraulic pressure provided from the first pressure chamber 112 is applied to the first hydraulic circuit 201 through the first hydraulic oil passage 211 and the second hydraulic oil passage 212 connected to the first communication hole 111a. It is transmitted directly to the wheel cylinder provided. At this time, the first and second inlet valves 221a and 221b respectively installed in the two flow paths branching from the first hydraulic circuit 201 are provided in an open state, and the two flow paths branching from the first hydraulic circuit 201 The first and second outlet valves 222a and 222b installed in the passages branched from each other are maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30.

In addition, the hydraulic pressure provided from the first pressure chamber 112 is provided to the second hydraulic circuit 202 through the first hydraulic oil passage 211 and the third hydraulic oil passage 213 connected to the first communication hole 111a. is transmitted directly to the wheel cylinder. At this time, the third and fourth inlet valves 221c and 221d respectively installed in the two flow paths branching from the second hydraulic circuit 202 are provided in an open state, and the two flow paths branching from the second hydraulic circuit 202 The third and outlet valves 222c installed in the passages branched from each other are maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30. In addition, as will be described later, since the second cut valve 262 of the second backup passage 251 is also closed during normal operation, the hydraulic pressure transmitted through the fourth inlet valve 221d is applied to the second backup passage 252. to prevent leakage. At this time, the sixth control valve 236 is also controlled to be open.

The third control valve 233 may be maintained in a closed state to block the fourth hydraulic oil passage 214 . Through this, the hydraulic pressure generated in the first pressure chamber 112 is prevented from being transferred to the second pressure chamber 113 through the fourth hydraulic oil passage 214, thereby improving the pressure increase rate per stroke of the hydraulic piston 114. . Accordingly, a rapid braking response can be achieved at the initial stage of braking.

When the hydraulic pressure of the braking fluid is generated by the hydraulic pressure supply device 100, the first and second cut valves 261 and 262 provided in the first and second backup passages 251 and 252 are closed, so that the integrated master cylinder 20 It is possible to prevent hydraulic pressure discharged from being transferred to the wheel cylinder. The hydraulic pressure generated in the master chamber 21a according to the pedal force of the brake pedal 10 is transmitted to the reaction force piston 22 . At this time, the simulator valve 26 provided in the simulation flow path 25 is closed so that the second simulation chamber 23a is sealed, and the diagnostic valve 66 provided in the first reservoir flow path 61 is opened so that the first simulation chamber 23a is closed. The simulation chamber 22a and the reservoir 30 communicate with each other. The braking fluid pressurized in the master chamber 21a by the master piston 21 is transmitted to the reaction force piston 22 to compress the elastic member 24, and the braking fluid accommodated in the first simulation chamber 22a is transferred to the first reservoir. It is transmitted to the reservoir 30 through the flow path 61, and a reaction force corresponding to the pedal force of the brake pedal 10 is acted upon by the elastic restoring force of the compressed elastic member 24, thereby providing an appropriate pedal feeling to the driver.

The hydraulic pressure supply device 100 of the electronic brake system 1 according to an embodiment of the present invention can switch from the low pressure mode shown in FIG. 4 to the high pressure mode shown in FIG. 5 before the hydraulic piston 114 moves forward to the maximum. can

Referring to FIG. 5 , the electronic control unit may switch from a low pressure mode to a high pressure mode when the hydraulic pressure detected by the flow pressure sensor PS1 is higher than a preset pressure level. In the high pressure mode, the third control valve 233 is switched to an open state to open the fourth hydraulic oil passage 214 . Therefore, some of the hydraulic pressure generated in the first pressure chamber 112 sequentially passes through the first hydraulic oil passage 211, the second hydraulic oil passage 212, and the fourth hydraulic oil passage 214 to the second pressure chamber 113. By being transmitted, the hydraulic piston 114 can be further advanced and at the same time, it can be used to reduce the load applied to the motor 120.

In the high pressure mode, the pressure increase rate per stroke decreases because a part of the braking fluid discharged from the first pressure chamber 112 flows into the second pressure chamber 113 . However, since some of the hydraulic pressure generated in the first pressure chamber 112 is utilized to further advance the hydraulic piston 114, the maximum pressure of the braking fluid may increase. This is because the second pressure chamber 113 has a relatively smaller volume change rate per stroke of the hydraulic piston 114 than the first pressure chamber 112 as the driving shaft 133 passes through the second pressure chamber 113. .

In addition, since the hydraulic pressure of the first pressure chamber 112 increases as the hydraulic piston 114 moves forward, the hydraulic pressure of the first pressure chamber 112 increases the force to move the hydraulic piston 114 backward, and accordingly the motor ( 120) also increases. However, by opening the fourth hydraulic circuit 214 under the control of the third control valve 233, part of the braking fluid discharged from the first pressure chamber 112 is transferred to the second pressure chamber 113, Hydraulic pressure is also formed in the second pressure chamber 113 to reduce the load applied to the motor 120 .

At this time, the second dump valve 242 may be switched to a closed state. When the second dump valve 242 is closed, the braking fluid in the first pressure chamber 112 can quickly flow into the second pressure chamber 113 under negative pressure, and hydraulic pressure can also be applied to the second pressure chamber 113. there is. However, if necessary, the second dump valve 242 may be kept open so that the braking fluid in the second pressure chamber 113 flows into the reservoir 30 .

Meanwhile, the electronic brake system 1 according to the embodiment of the present invention may provide braking pressure to the wheel cylinder 40 while the hydraulic piston 114 moves backward. Specifically, when the driver steps on the brake pedal 10 at the beginning of braking, the motor 120 operates to rotate in the opposite direction, and the rotational force of the motor 120 is transferred to the hydraulic pressure supply unit 110 by the power transmission unit 130. and while the hydraulic piston 114 of the hydraulic pressure providing unit 110 moves backward, hydraulic pressure is generated in the second pressure chamber 113. The hydraulic pressure discharged from the second pressure chamber 113 is transmitted to the wheel cylinders 40 provided on each of the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate braking force.

Specifically, the hydraulic pressure provided from the second pressure chamber 113 is applied to the first hydraulic circuit 201 through the fourth hydraulic oil passage 214 and the second hydraulic oil passage 212 connected to the second communication hole 111b. It is transmitted directly to the two wheel cylinders 40 provided. At this time, the first and second inlet valves 221a and 221b are provided in an open state, and the first and second outlet valves 222a and 222b are maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30. prevent.

In addition, the hydraulic pressure provided from the second pressure chamber 113 sequentially passes through the fourth hydraulic oil passage 214, the seventh hydraulic oil passage 217, and the third hydraulic oil passage 213 connected to the second communication hole 111b. It passes through and is directly transmitted to the wheel cylinder 40 provided in the second hydraulic circuit 202. At this time, the third and fourth inlet valves 221c and 221d are provided in an open state, and the third outlet valve 222 and the second cut valve 262 are maintained in a closed state so that the hydraulic pressure is applied to the reservoir 30 and Leakage to the second backup passage 252 is prevented.

At this time, the third control valve 233 is controlled in an open state to open the fourth hydraulic oil passage 214, and the seventh control valve 237 operates from the second pressure chamber 113 to the third and fourth wheel cylinders. Since it is provided as a check valve allowing the flow of braking fluid in the directions (43, 44), the seventh hydraulic oil passage 317 is also opened.

In addition, the sixth control valve 236 may be maintained in a closed state to block the sixth hydraulic oil passage 216 . This prevents the hydraulic pressure generated in the second pressure chamber 113 from leaking into the first pressure chamber 112 through the sixth hydraulic oil passage 216, thereby improving the pressure increase rate per stroke of the hydraulic piston 114. A quick braking response can be achieved at the initial stage of braking.

The second dump valve 242 may be switched to a closed state. When the second dump valve 242 is closed, the hydraulic pressure of the braking fluid can be quickly and stably generated in the second pressure chamber 113, and the hydraulic pressure generated in the second pressure chamber 113 flows through the fourth hydraulic fluid ( 214) can only be discharged.

Hereinafter, an operating state in which braking pressure is released in a normal operating state of the electronic brake system 1 according to an embodiment of the present invention will be described.

6 is a hydraulic circuit diagram showing a state in which the hydraulic piston 114 of the electronic brake system 1 according to an embodiment of the present invention releases the braking pressure in the high pressure mode while moving backward, and FIG. 7 is a diagram according to an embodiment of the present invention It is a hydraulic circuit diagram showing a state in which the hydraulic piston 114 of the electronic brake system 1 moves backward and releases the braking pressure in the low pressure mode.

Referring to FIG. 6, when the pedal force applied to the brake pedal 10 is released, the motor 120 generates rotational force in the opposite direction during braking and transmits it to the power conversion unit 130, and the worm of the power conversion unit 130 The shaft 131, the worm wheel 132, and the driving shaft 133 rotate in the opposite direction during braking to reverse the hydraulic piston 114 to its original position. Accordingly, the hydraulic pressure of the first pressure chamber 112 may be released and negative pressure may be generated. At the same time, the braking fluid discharged from the wheel cylinder is transferred to the first pressure chamber 112 through the first and second hydraulic circuits 201 and 202 .

Specifically, the negative pressure generated in the first pressure chamber 112 is supplied through the second hydraulic oil passage 212, the fifth hydraulic oil passage 215, the sixth hydraulic oil passage 216, and the first hydraulic oil passage 211. The pressure of the first and second wheel cylinders 41 and 42 provided in the hydraulic circuit 201 is released. At this time, the first and second inlet valves 221a and 221b respectively installed in the two flow paths diverging from the first hydraulic circuit 201 remain open, and the two flow paths diverging from the second hydraulic circuit 201 The first and second outlet valves 222a and 222b installed in the flow paths branched from each other are maintained in a closed state to prevent the braking fluid in the reservoir 30 from flowing into the first pressure chamber 112 . At this time, the sixth control valve 236 provided in the sixth hydraulic oil passage 216 is controlled in an open state.

In addition, the negative pressure generated in the first pressure chamber 112 is transmitted through the third hydraulic oil passage 213, the fifth hydraulic oil passage 215, the sixth hydraulic oil passage 216, and the first hydraulic oil passage 213 connected to the first communication hole 111a. The pressure of the third and fourth wheel cylinders 43 and 44 provided in the second hydraulic circuit 202 is released through the hydraulic oil passage 211 . At this time, the third and fourth inlet valves 221c and 221d respectively installed in the two flow paths diverging from the second hydraulic circuit 202 remain open, and the two flow paths diverging from the second hydraulic circuit 202 The third outlet valve 222 and the second cut valve 252 installed in the passages branched from are kept closed so that the braking fluid in the reservoir 30 and the braking fluid on the second backup passage 252 are maintained in the first It is prevented from flowing into the pressure chamber 112.

Meanwhile, the third control valve 233 is also switched to an open state to open the fourth hydraulic oil passage 214, so that the first pressure chamber 112 and the second pressure chamber 113 communicate with each other.

That is, in order to form negative pressure in the first pressure chamber 112, the hydraulic piston 114 has to move backward, but when the hydraulic pressure of the braking fluid exists in the second pressure chamber 113, resistance to the backward movement of the hydraulic piston 114 exists. this happens Therefore, by switching the third control valve 233 to an open state and communicating the first pressure chamber 112 and the second pressure chamber 113, the braking fluid in the second pressure chamber 113 flows into the first pressure chamber 112. ) can be supplied.

At this time, the second dump valve 242 may be switched to a closed state. When the second dump valve 242 is closed, the braking fluid in the second pressure chamber 113 can be discharged only through the fourth hydraulic oil passage 214 . However, if necessary, the second dump valve 242 may be kept open so that the braking fluid in the second pressure chamber 113 flows into the reservoir 30 .

In addition, when the negative pressure transmitted to the first and second hydraulic circuits 201 and 202 is higher than the target pressure release value according to the release amount of the brake pedal 10, the first to third outlet valves 222 At least one of them may be opened and controlled to correspond to a target pressure value. In addition, the first and second cut valves 261 and 262 installed in the first and second backup passages 251 and 252 are closed, and the negative pressure formed in the integrated master cylinder 20 is transmitted to the hydraulic control unit 200. It can be controlled so that it does not happen.

On the other hand, in the operating state of the high pressure mode shown in FIG. 6, the braking fluid in the wheel cylinder as well as the braking fluid in the second pressure chamber 113 is controlled by the negative pressure in the first pressure chamber 112 generated while the hydraulic piston 114 moves backward. Since the fluid is supplied to the first pressure chamber 112, the pressure reduction rate of the wheel cylinder is small. Therefore, it may be difficult to quickly release the braking pressure in the high pressure mode. For this reason, the braking pressure release operation in the high pressure mode can be used only in the high pressure situation of the braking pressure, and when the braking pressure is below a certain level, it can be switched to the braking pressure release operation in the low pressure mode shown in FIG. 7 to quickly release the braking pressure. can

Referring to FIG. 7 , when the braking pressure is released in the low pressure mode, the third control valve 233 is maintained or switched to a closed state, and instead of closing the fourth hydraulic oil passage 214, the second dump valve 242 operates. It is switched or maintained in an open state so that the second pressure chamber 113 and the reservoir 30 can communicate with each other.

When the braking pressure is released in the low pressure mode, the negative pressure generated in the first pressure chamber 112 is used only to recover the braking fluid in the wheel cylinder, so the stroke of the hydraulic piston 114 is compared to the case where the braking pressure is released in the high pressure mode. The rate of decrease in sugar pressure increases. At this time, the hydraulic pressure generated in the second pressure chamber 113 by the backward movement of the hydraulic piston 114 is transferred to the reservoir 30 as the second dump valve 242 is switched to an open state.

Meanwhile, unlike FIG. 7 , the braking pressure of the wheel cylinder may be released even when the hydraulic piston 114 moves forward.

Specifically, when the pedal force applied to the brake pedal 10 is released, the motor 120 generates rotational force in the opposite direction during braking and transmits it to the power conversion unit 130, and the worm shaft 131 of the power conversion unit 130 ), the worm wheel 132, and the driving shaft 133 rotate in the opposite direction during braking to advance the hydraulic piston 114 to its original position, thereby releasing the hydraulic pressure in the second pressure chamber 113 and generating negative pressure. At the same time, the braking fluid discharged from the wheel cylinder is transferred to the second pressure chamber 113 through the first and second hydraulic circuits 201 and 202 .

Specifically, the negative pressure generated in the second pressure chamber 113 is supplied to the first hydraulic circuit 201 through the fourth hydraulic oil passage 214 and the second hydraulic oil passage 212 connected to the second communication hole 111b. The pressure of the first and second wheel cylinders 41 and 42 provided is released. At this time, the first and second inlet valves 221a and 221b respectively installed in the two flow paths diverging from the first hydraulic circuit 201 remain open, and the two flow paths diverging from the first hydraulic circuit 201 The first and second outlet valves 222a and 222b installed in the passages branched from each other are maintained in a closed state to prevent the braking fluid in the reservoir 30 from flowing into the second pressure chamber 113.

In addition, the negative pressure generated in the second pressure chamber 113 is transmitted through the fourth hydraulic oil passage 214, the second hydraulic oil passage 212, the sixth hydraulic oil passage 216, and the fifth hydraulic oil passage 214 connected to the second communication hole 111b. The pressure of the wheel cylinder provided in the second hydraulic circuit 202 may be released through the oil passage on the side of the fifth control valve 235 of the hydraulic oil passage 215 and the third hydraulic oil passage 213 . At this time, the third and fourth inlet valves 221c and 221d respectively installed in the two flow paths diverging from the second hydraulic circuit 202 remain open, and the two flow paths diverging from the second hydraulic circuit 202 The third outlet valve 222c and the second cut valve 262 installed in the passages branched from each other are maintained in a closed state so that the braking fluid of the reservoir 30 and the braking fluid of the second backup passage 252 It is prevented from flowing into the pressure chamber 113.

At this time, the third control valve 233 is switched to an open state to open the fourth hydraulic oil passage 214, and the sixth control valve 236 is also switched to an open state to open the sixth hydraulic oil passage 216. can be controlled

In addition, the second dump valve 242 can be switched to a closed state, whereby the negative pressure generated in the second pressure chamber 113 can quickly recover the braking fluid in the wheel cylinder.

In addition, when the negative pressure transmitted to the first and second hydraulic circuits 201 and 202 is higher than the target pressure release value according to the release amount of the brake pedal 10, the first to third outlet valves 222 At least one of them may be opened and controlled to correspond to a target pressure value. In addition, the first and second cut valves 261 and 262 installed in the first and second backup passages 251 and 252 are closed, and the negative pressure formed in the integrated master cylinder 20 is transmitted to the hydraulic control unit 200. It can be controlled so that it does not happen.

Hereinafter, when the electronic brake system 1 according to an embodiment of the present invention does not normally operate, that is, an operating state in the fallback mode will be described.

8 is a hydraulic circuit diagram showing an abnormally operating state of the electronic brake system 1 according to an embodiment of the present invention.

Referring to FIG. 8 , when the electronic brake system 1 does not operate normally, each valve is controlled to an initial braking state in a non-operating state. Then, when the driver presses the brake pedal 10, the master piston 21 connected to the brake pedal 10 advances, and the movement of the master piston 21 pressurizes the braking fluid accommodated in the master chamber 21a. . The braking fluid pressurized in the master chamber 21a is delivered to the first and second wheel cylinders 41 and 42 through the first backup passage 251 to implement braking.

In addition, the braking fluid pressurized in the master chamber 21a advances the reaction force piston 22, and by the advancement of the reaction force piston 22, the damping piston 23 also advances together, thereby moving the reaction force accommodated in the second simulation chamber 23a. The braking fluid flows into the first simulation chamber 22a through the simulation passage 25, and the braking fluid accommodated in the first simulation chamber 22a passes through the second reservoir passage 62 and the second backup passage 252. It is transmitted to the third and fourth wheel cylinders 43 and 44 to implement braking.

At this time, the first and second cut valves 261 and 262 provided in the first and second backup oil passages 251 and 252 and the first to second valves provided in the first and second hydraulic circuits 201 and 202 The fourth inlet valve 221 is controlled to be open, and the diagnostic valve 66 of the second reservoir passage 62 is controlled to be closed, so that the master chamber 21a of the integrated master cylinder 20 and Since the hydraulic pressure generated in the first simulation chamber 22a can be directly transferred to the four wheel cylinders, braking stability can be improved and rapid braking can be achieved.

10: brake pedal 11: pedal displacement sensor
20: integrated master cylinder 21: master piston
21a: master chamber 22: reaction piston
22a: first simulation chamber 23: damping piston
23a: second simulation chamber 24: elastic member
25: simulation euro 26: simulator valve
40: wheel cylinder 61: first reservoir flow path
62: second reservoir flow 66: diagnostic valve
100: hydraulic pressure supply unit 110: hydraulic pressure supply unit
120: motor 130: power conversion unit
200: hydraulic control unit 201: first hydraulic circuit
202: second hydraulic circuit 211: first hydraulic oil path
212: second hydraulic oil path 213: third hydraulic oil path
214: fourth hydraulic oil path 215: fifth hydraulic oil path
216: sixth hydraulic oil passage 217: seventh hydraulic oil passage
221: inlet valve 222: outlet valve
231: first control valve 232: second control valve
233: third control valve 234: fourth control valve
235: fifth control valve 236: sixth control valve
237: 7th control valve 241: 1st dump valve
242: second dump valve 243: third dump valve
251: first backup passage 252: second backup passage
261: first cut valve 262: second cut valve

Claims (10)

a reservoir in which braking fluid is stored;
A master chamber, a master piston provided in the master chamber and provided to be displaceable by a brake pedal, first and second simulation chambers, and hydraulic pressure of braking fluid provided in the first simulation chamber and accommodated in the master chamber a damping piston provided in the second simulation chamber, provided to be displaceable by displacement of the reaction force piston, and provided to be able to pressurize the braking fluid accommodated in the second simulation chamber; an integrated master cylinder having an elastic member disposed between the reaction force piston and the damping piston, wherein both sides of the elastic member contact the reaction force piston and the damping piston to elastically support the reaction force piston and the damping piston;
a reservoir passage communicating the integrated master cylinder and the reservoir;
A first pressure chamber that generates hydraulic pressure by operating a hydraulic piston by an electrical signal output in response to the displacement of the brake pedal, provided on one side of the hydraulic piston movably accommodated in the cylinder block and connected to one or more wheel cylinders And a hydraulic pressure supply device including a second pressure chamber provided on the other side of the hydraulic piston and connected to one or more wheel cylinders; and
An electronic brake system including a hydraulic control unit having a first hydraulic circuit for controlling hydraulic pressure transmitted to two wheel cylinders and a second hydraulic circuit for controlling hydraulic pressure transmitted to other two wheel cylinders. According to claim 1,
The integrated master cylinder
The electronic brake system further comprises a simulation flow path communicating the first simulation chamber and the second simulation chamber, and a simulator valve provided in the simulation flow path to control a flow of braking fluid. According to claim 2,
The integrated master cylinder
The electronic brake system further includes a reaction spring provided in the second simulation chamber and elastically supporting the damping piston. According to claim 3,
The reservoir flow is
A first reservoir passage communicating the master chamber and the reservoir, and a second reservoir passage communicating the first simulation chamber and the reservoir,
a reservoir check valve provided in the first reservoir flow path and allowing only a flow of braking fluid from the reservoir toward the master chamber;
The electronic brake system further comprises a diagnostic valve provided in the second reservoir passage to control the flow of braking fluid in both directions. According to claim 4,
The hydraulic control unit
A first hydraulic oil passage communicating with the first pressure chamber, second and third hydraulic oil passages diverging from the first hydraulic oil passage and connected to the first and second hydraulic circuits, respectively, communicating with the second pressure chamber and a fourth hydraulic oil path connected to the second hydraulic oil path, a fifth hydraulic oil path connecting the second hydraulic oil path and the third hydraulic oil path, and a first hydraulic oil path connecting the second hydraulic oil path and the fifth hydraulic oil path. 6 a hydraulic oil passage, a seventh hydraulic oil passage communicating with the second pressure chamber and connected to the third hydraulic oil passage, a first control valve provided in the second hydraulic oil passage to control the flow of braking fluid, and the third hydraulic oil passage A second control valve provided in the hydraulic oil passage to control the flow of braking fluid, a third control valve provided in the fourth hydraulic oil passage to control the flow of braking fluid, and the sixth hydraulic oil passage on the fifth hydraulic oil passage are connected. A fourth control valve provided between a point and a point where the second hydraulic oil path is connected, and a fifth control valve provided between a point where the sixth hydraulic oil path is connected and a point where the third hydraulic oil path is connected on the fifth hydraulic oil path. An electronic brake system including a valve, a sixth control valve provided in the sixth hydraulic oil passage, and a seventh control valve provided in the seventh hydraulic oil passage. According to claim 5,
The third and sixth control valves are provided as solenoid valves that control the flow of braking fluid in both directions,
The first control valve is provided as a check valve that allows only the flow of braking fluid in a direction from the first pressure chamber to the first hydraulic circuit,
The second control valve is provided as a check valve that allows only the flow of braking fluid in a direction from the first pressure chamber to the second hydraulic circuit,
The fourth control valve is provided as a check valve that allows only the flow of braking fluid in a direction from the second hydraulic oil passage to a point where the sixth hydraulic oil passage is connected,
The fifth control valve is provided as a check valve that allows only the flow of braking fluid in a direction from the third hydraulic oil passage to a point where the sixth hydraulic oil passage is connected,
The seventh control valve is provided as a check valve that allows only the flow of braking fluid in a direction from the second pressure chamber to the second hydraulic circuit. According to claim 6,
a pedal displacement sensor that detects a displacement of the brake pedal; and
An electronic control unit for controlling valves based on hydraulic pressure information and displacement information of the brake pedal; further comprising;
The electronic control unit
The electronic brake system controls to open the sixth control valve when the pedal displacement sensor detects the displacement of the brake pedal. According to claim 7,
Further comprising a flow pressure sensor for sensing the hydraulic pressure of at least one of the first hydraulic circuit and the second hydraulic circuit,
The electronic control unit
When the hydraulic pressure detected by the flow path pressure sensor is higher than a preset pressure level, the third control valve is opened to supply at least a part of the braking fluid discharged from the first pressure chamber to the second pressure chamber. system. According to claim 8,
a first backup passage connecting the master chamber and the first hydraulic circuit;
a second backup passage connecting the simulation chamber and the second hydraulic circuit;
a first cut valve selectively opening and closing the first backup passage; and
A second cut valve for selectively opening and closing the second backup passage; further comprising,
The first hydraulic circuit includes first and second inlet valves respectively controlling the hydraulic pressure supplied to the first and second wheel cylinders, and first and second inlet valves respectively controlling the hydraulic pressure discharged from the first and second wheel cylinders to the reservoir. And a second outlet valve,
The second hydraulic circuit includes third and fourth inlet valves respectively controlling the hydraulic pressure supplied to the third and fourth wheel cylinders, and a third outlet valve respectively controlling the hydraulic pressure discharged from the third wheel cylinder to the reservoir. include,
The second backup passage is
An electronic brake system provided to connect the simulation chamber and the downstream side of the fourth inlet valve of the second hydraulic circuit. According to claim 9,
a first dump passage connecting the first pressure chamber and the reservoir;
a second dump passage connecting the second pressure chamber and the reservoir;
a first dump valve provided as a check valve provided in the first dump passage to control a flow of the braking fluid and allowing only a flow of the braking fluid in a direction from the reservoir to the first pressure chamber;
a second dump valve provided as a solenoid valve provided in the second dump passage to control the flow of the braking fluid and controlling the flow of the braking fluid in both directions between the reservoir and the second pressure chamber;
a third dump valve provided as a check valve provided in a bypass passage connected in parallel to the second dump valve on the second dump passage and allowing only a flow of braking fluid from a reservoir toward the second pressure chamber; Electronic brake system further comprising a.

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