KR102373397B1 - Electric brake system and Control Method thereof - Google Patents

Abstract

Disclosed are an electronic brake system and a method for controlling the same. An electronic brake system and a control method thereof according to an embodiment of the present invention include: a reservoir in which oil is stored; a master cylinder connected to the reservoir and having first and second master chambers and first and second pistons provided in each master chamber to discharge oil according to a pressing force of a brake pedal; a hydraulic pressure supply device that operates by an electrical signal to generate hydraulic pressure; a hydraulic control unit for transmitting the hydraulic pressure discharged from the hydraulic pressure supply device to the wheel cylinders provided on the two wheels, respectively, and provided separately into a first hydraulic circuit connected to the rear wheel and a second hydraulic circuit connected to the front wheel; and a regenerative control valve provided in the hydraulic flow path connecting the hydraulic pressure supply device and the first hydraulic circuit to open and close when regenerative braking force is generated in the rear wheel. , control so that the hydraulic braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit connected to the rear wheel is reduced by using the regenerative control valve in response to the regenerative braking force.

Description

Electronic brake system and control method thereof

The present invention relates to an electronic brake system and a control method thereof, and more particularly, to generate hydraulic braking force according to an electrical signal corresponding to the displacement of a brake pedal and effectively control cooperative braking of two braking forces in a vehicle in which regenerative braking force is generated. It relates to an electronic brake system and a control method therefor.

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

An example of the brake system is an anti-lock brake system (ABS) that prevents wheel slippage during braking, and a brake traction control system (BTCS: Brake) that prevents slipping of the driving wheels when the vehicle starts or accelerates rapidly. Traction Control System), and an Electronic Stability Control System (ESC) that maintains a stable driving state of a vehicle by controlling brake fluid pressure by combining an anti-lock brake system and traction control.

The conventional brake system supplies hydraulic pressure required for braking to the wheel cylinders using a mechanically connected vacuum booster when the driver steps on the brake pedal. An electronic brake system equipped with a hydraulic pressure supply device that receives the driver's will to brake as an electrical signal and supplies the hydraulic pressure required for braking to the wheel cylinders is widely used.

EP 2 520 473 A1 (Honda Motor Co., Ltd.) 2012. 11. 07. According to the document, in the hydraulic pressure supply device of the electronic brake system, the motor operates according to the pedal force of the brake pedal, and the rotational force of the motor is converted into linear motion to pressurize the piston of the cylinder to generate hydraulic pressure required for braking. On the other hand, in a vehicle that uses a motor as the main or auxiliary drive source, such as an electric vehicle or a hybrid vehicle, when braking, the regenerative braking force by the motor is added to the hydraulic braking force that is equally applied to the four wheels during braking. Cooperative control between the two braking forces must be closely performed so that the total braking force acting on the motor is constant. For example, when the motor is installed on the front wheel as shown in FIG. Since it is greater than the total braking force (RTB) of the rear wheels that only occurs, there is no major problem in braking safety. However, as shown in FIG. 1(b), when the motor is installed on the rear wheel, the hydraulic braking force (HB) and the regenerative braking force by the motor ( MB) plus the total braking force (RTB) of the rear wheels is large, so if the two braking forces are not properly adjusted, there is a risk of a problem in the braking safety of the vehicle.

According to an embodiment of the present invention, it is an object of the present invention to provide an electronic brake system capable of effectively performing cooperative control for stable braking in a vehicle to which hydraulic braking force and regenerative braking force act, and a method for controlling the same.

According to an aspect of the present invention, a reservoir in which oil is stored; a master cylinder connected to the reservoir and having first and second master chambers and first and second pistons provided in each master chamber to discharge oil according to a pressing force of a brake pedal; a hydraulic pressure supply device that operates by an electrical signal to generate hydraulic pressure; a hydraulic control unit for transmitting the hydraulic pressure discharged from the hydraulic pressure supply device to the wheel cylinders provided on the two wheels, respectively, and provided separately into a first hydraulic circuit connected to the rear wheel and a second hydraulic circuit connected to the front wheel; and a regenerative control valve provided in the hydraulic flow path connecting the hydraulic pressure supply device and the first hydraulic circuit and opened and closed when a regenerative braking force is generated on the rear wheel; an electronic brake system including a can be provided.

In addition, hydraulic braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit and the second hydraulic circuit may vary according to opening and closing of the regenerative control valve.

In addition, the first hydraulic pressure sensor for detecting the hydraulic pressure of the first hydraulic circuit and a second hydraulic pressure sensor for sensing the hydraulic pressure of the second hydraulic circuit, the regenerative control valve is the first hydraulic oil The opening/closing control may be performed so that the hydraulic pressure sensed by the furnace pressure sensor and the second hydraulic passage pressure sensor is at least the same or the hydraulic pressure of the first hydraulic passage pressure sensor is smaller than the hydraulic pressure of the second hydraulic passage pressure sensor.

In addition, the hydraulic pressure supply device is connected to a motor operated by an electrical signal output in response to the displacement of the brake pedal, a power conversion unit for converting the rotational force of the motor into a translational motion, a cylinder block, and the power conversion unit and a hydraulic piston movably accommodated in the cylinder block, a first pressure chamber provided on one side of the hydraulic piston 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 a first hydraulic flow passage including a pressure chamber and communicating with the first pressure chamber; a second hydraulic oil passage branched from the first hydraulic oil passage; a third hydraulic oil passage branched from the first hydraulic oil passage; a fourth hydraulic flow passage communicating with the second pressure chamber; a fifth hydraulic oil passage branching from the fourth hydraulic oil passage and joining the second hydraulic oil passage and the third hydraulic oil passage; It may further include; a sixth hydraulic oil passage branched from the fourth hydraulic oil passage to join the second hydraulic oil passage and the third hydraulic oil passage.

In addition, a first control valve provided in the second hydraulic flow path to control the flow of oil; a second control valve provided in the third hydraulic flow path to control the flow of oil; a third control valve provided in the fifth hydraulic flow path to control the flow of oil; and a fourth control valve provided in the sixth hydraulic flow path to control the flow of oil.

In addition, the first control valve, the second control valve, and the fourth control valve are provided as check valves that allow the flow of oil in a direction from the hydraulic pressure supply device to the wheel cylinder, but block the flow of oil in the opposite direction. and the fifth control valve may be provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the wheel cylinder.

In addition, a seventh hydraulic oil passage communicating with the second hydraulic oil passage and the third hydraulic oil passage, and a fifth control valve provided in the seventh hydraulic oil passage to control the flow of oil, wherein the fifth control valve is the It may be provided as a solenoid valve that controls the flow of oil in both directions between the hydraulic pressure supply device and the wheel cylinder.

In addition, an eighth hydraulic oil passage communicating the second hydraulic oil passage and the seventh hydraulic oil passage, and a sixth control valve provided in the eighth hydraulic oil passage to control the flow of oil, wherein the sixth control valve is the It is possible to control the flow of oil in both directions between the hydraulic supply and the wheel cylinder.

In addition, a first control valve provided in the second hydraulic flow path to control the flow of oil; a second control valve provided in the third hydraulic flow path to control the flow of oil; a third control valve provided in the fifth hydraulic flow path to control the flow of oil; and a fourth control valve provided in the sixth hydraulic flow path to control the flow of oil, wherein the first to fourth control valves allow the flow of oil in a direction from the hydraulic pressure supply device to the wheel cylinder. , may be provided as a check valve to block the flow of oil in the opposite direction.

According to another aspect of the present invention, in the method of controlling the electronic brake system provided as described above, it is determined whether regenerative braking force is generated in the rear wheels of the vehicle, and when the regenerative braking force is generated, the hydraulic pressure supply device is connected to the rear wheels The control method of the electronic brake system in which the hydraulic braking force transmitted to the first hydraulic circuit is controlled to be reduced in response to the regenerative braking force may be provided.

In addition, the sum of the hydraulic braking force and the regenerative braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit may be at least equal to or smaller than the hydraulic braking force transmitted to the second hydraulic circuit.

The electronic brake system and its control method according to an embodiment of the present invention detect when a regenerative braking force is generated, and deliver hydraulic pressure from the hydraulic pressure supply device to the first hydraulic circuit and the second hydraulic circuit for controlling two wheel cylinders, respectively. When the regenerative braking force is generated, a hydraulic braking force obtained by reducing the hydraulic pressure in response to the regenerative braking force is provided to the corresponding hydraulic circuit of the wheel cylinder, so that a safe braking operation can be performed.

In addition, the electromagnetic brake system and the control method thereof according to an embodiment of the present invention control the hydraulic braking force of the hydraulic circuit according to the regenerative braking force in the hydraulic flow path between the hydraulic pressure supply device and the hydraulic circuit in the form of a normally open solenoid valve. Since the control valve is installed and controlled, structurally simple and effective cooperative control is possible.

1 is a diagram schematically illustrating overall braking force control characteristics of a front-wheel or rear-wheel drive vehicle in which regenerative braking force is generated.
2 is a hydraulic circuit diagram illustrating a non-braking state of the electronic brake system according to an embodiment of the present invention.
3 is an enlarged view illustrating a master cylinder and a reservoir of an electronic brake system according to an embodiment of the present invention.
4 is an enlarged view illustrating a hydraulic pressure supply unit provided in the hydraulic pressure supply device of the electronic brake system according to an embodiment of the present invention.
5 is a flowchart illustrating a hydraulic braking force control operation of the hydraulic pressure supply device when regenerative braking force is generated in the electronic brake system according to an embodiment of the present invention.
6 is a diagram schematically illustrating a hydraulic pressure supply device according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numerals refer to like elements throughout.

FIG. 2 is a hydraulic circuit diagram illustrating a non-braking state of the electronic brake system 1 according to an embodiment of the present invention.

Referring to the drawings, the electronic brake system 1 typically includes a master cylinder 20 generating hydraulic pressure, a reservoir 30 coupled to an upper portion of the master cylinder 20 to store oil, and a brake pedal 10 . ), the input rod 12 for pressing the master cylinder 20 according to the pedal force, the wheel cylinder 40 for braking each wheel (RR, RL, FR, FL) by transmitting hydraulic pressure, and the brake pedal ( A pedal displacement sensor 11 for detecting the displacement of 10) and a simulation device 50 for providing a reaction force according to the pedal effort of the brake pedal 10 are provided.

The master cylinder 20 may be configured to include at least one chamber to generate hydraulic pressure. For example, the master cylinder 20 may include a first master chamber 20a and a second master chamber 20b.

The master cylinder 20 according to the present embodiment will be described in more detail with reference to the enlarged view of FIG. 3 .

A first piston 21a connected to the input rod 12 is provided in the first master chamber 20a, and a second piston 22a is provided in the second master chamber 20b. In addition, the first master chamber 20a communicates with the first hydraulic port 24a so that oil flows in and out, and the second master chamber 20b communicates with the second hydraulic port 24b and oil flows in and out. For example, the first hydraulic port 24a may be connected to the first backup passage 251 , and the second hydraulic port 24b may be connected to the second backup passage 252 .

The master cylinder 20 has two master chambers 20a and 20b to ensure safety in case of failure. For example, one master chamber 20a among the two master chambers 20a and 20b is connected to the right rear wheel RR and the left rear wheel RL of the vehicle through the first backup flow path 251 , and the other master chamber 20a The chamber 20b may be connected to the right front wheel FR and the left front wheel FL through the second backup flow path 252 . In this way, by independently configuring the two master chambers 20a and 20b, it is possible to enable braking of the vehicle even when one master chamber fails.

Alternatively, unlike shown in the drawing, one master chamber of the two master chambers is installed diagonally to one front wheel and one rear wheel (FR, RL), and the other master chamber is placed diagonally to one front wheel and rear wheel ( RR, FL) can also be connected. In addition, one master chamber of the two master chambers may be connected to the left front wheel FL and the left rear wheel RL, and the other master chamber may be connected to the right rear wheel RR and the right front wheel FR. That is, the position of the wheel connected to the master chamber of the master cylinder 20 may be variously configured.

In addition, a first spring 21b is provided between the first piston 21a and the second piston 22a of the master cylinder 20, and the second piston 22a and the end of the master cylinder 20 are disposed between the first piston 21a and the second piston 22a. Two springs 22b may be provided. That is, the first piston 21b may be accommodated in the first master chamber 20a, and the second piston 22b may be accommodated in the second master chamber 20b.

The first spring 21b and the second spring 22b are compressed by the first piston 21a and the second piston 22a that move as the displacement of the brake pedal 10 changes, and elastic force is stored therein. When the force pushing the first piston 21a is smaller than the elastic force, the first and second pistons 21a and 22a are pushed back to their original state by using the restoring elastic force stored in the first spring 21b and the second spring 22b. can

The input rod 12 for pressing the first piston 21a of the master cylinder 20 may be in close contact with the first piston 21a. That is, a gap may not exist between the master cylinder 20 and the input rod 12 . Therefore, when the brake pedal 10 is pressed, the master cylinder 20 can be directly pressed without a pedal invalid stroke section.

In addition, the first master chamber 20a is connected to the reservoir 30 through the first reservoir flow path 61 , and the second master chamber 20b is connected to the reservoir 30 through the second reservoir flow path 62 . can

In addition, the master cylinder 20 includes two sealing members 25a and 25b disposed before and after the first reservoir flow path 61 and two sealing members 25c and 25d disposed before and after the second reservoir flow path 62 . ) may be included. The sealing members 25a, 25b, 25c, and 25d may have a ring shape protruding from the inner wall of the master cylinder 20 or the outer peripheral surface of the pistons 21a and 22a.

In addition, in the first reservoir flow path 61 , the flow of oil flowing from the reservoir 30 to the first master chamber 20a is allowed while the flow of oil flowing into the reservoir 30 from the first master chamber 20a is A check valve 64 for blocking may be provided.

The front and rear sides of the check valve 64 of the first reservoir flow path 61 may be connected by the bypass flow path 63 , and the check valve 60 may be provided in the bypass flow path 63 .

The inspection valve 60 may be provided as a bidirectional control valve for controlling the oil flow between the reservoir 30 and the master cylinder 20 . The inspection valve 60 may be provided as a normal open type solenoid valve that is normally open and operates to close when a closing signal is received from the electronic control unit. The inspection valve 60 is for detecting a leak of the simulator valve 54, and this inspection mode may be executed under preset conditions through the electronic control unit while driving or stopping.

Meanwhile, the reservoir 30 may include three reservoir chambers 31 , 32 , and 33 . For example, the three reservoir chambers 31 , 32 , and 33 may be arranged side by side in a row.

Adjacent reservoir chambers 31 , 32 , and 33 may be separated by partition walls 34 and 35 . For example, the first reservoir chamber 31 and the second reservoir chamber 32 are divided by a first partition wall 34 , and the second reservoir chamber 32 and the third reservoir chamber 33 are separated by a second partition wall ( 35) can be distinguished.

The first partition wall 34 and the second partition wall 35 may be partially opened so that the first to third reservoir chambers 31 , 32 , and 33 may communicate with each other. Accordingly, the pressures of the first to third reservoir chambers 31 , 32 , and 33 may be equal to each other, for example, the pressure may be equal to atmospheric pressure.

The first reservoir chamber 31 may be connected to the first master chamber 20a of the master cylinder 20 , the wheel cylinder 40 , and the simulation device 50 . That is, the first reservoir chamber 31 may be connected to the first master chamber 20a through the first reservoir flow path 61 , and also two wheel cylinders RR and RL among the four wheel cylinders 40 . It may be connected to the wheel cylinder 40 of the first hydraulic circuit 201 to be disposed.

The connection between the first reservoir chamber 31 and the first master chamber 20a may be controlled by the check valve 64 and the inspection valve 60 as shown in FIG. 2 , and the first reservoir chamber 31 The connection between the and the simulation device 50 may be controlled by the simulator valve 54 and the simulator check valve 55 . The connection between the first reservoir chamber 31 and the wheel cylinder 40 may be controlled by the first and second outlet valves 222a and 222b.

The second reservoir chamber 32 may be connected to a hydraulic pressure supply device 100 to be described later. Referring to FIG. 2 , the second reservoir chamber 32 may be connected to the first pressure chamber 112 and the second pressure chamber 113 of the hydraulic pressure providing unit 110 . More specifically, the second reservoir chamber 32 is connected to the first pressure chamber 112 through the first dump passage 116 , and is connected to the second pressure chamber 113 through the second dump passage 117 . can

The third reservoir chamber 33 may be connected to the second master chamber 20b of the master cylinder 20 and the wheel cylinder 40 . Referring to FIG. 2 , the third reservoir chamber 33 may be connected to the second master chamber 20b through the second reservoir flow path 62 , and the other two wheel cylinders FR among the four wheel cylinders 40 . , FL) may be connected to the wheel cylinder 40 of the second hydraulic circuit 202 is disposed. The connection between the third reservoir chamber 33 and the wheel cylinder 40 may be controlled by the third and fourth outlet valves 222c and 222d.

Meanwhile, the reservoir 30 includes a second reservoir chamber 32 connected to the hydraulic pressure supply device 100 and first and third reservoir chambers 31 and 33 connected to the first and second master chambers 20a and 20b. ) can be prepared separately. This is, if the reservoir chamber for supplying oil to the hydraulic supply device 100 and the reservoir chamber for supplying oil to the master chambers 20a and 20b are equally provided, the reservoir 20 is properly supplied to the hydraulic supply device 100 . This is because, if oil is not supplied, oil may not be properly supplied to the master chambers 20a and 20b.

Therefore, the reservoir 30 separates the second reservoir chamber 32 and the first and third reservoir chambers 31 and 33 to provide a reservoir even in an emergency in which oil cannot be properly supplied to the hydraulic pressure supply device 100 . 30 may normally supply oil to the first and second master chambers 20a and 20b so that emergency braking is performed.

Similarly, the reservoir 30 may be provided by separating the first reservoir chamber 32 connected to the first master chamber 20a and the third reservoir chamber 33 connected to the second master chamber 20b. This is, if the reservoir chamber for supplying oil to the first master chamber 20a and the reservoir chamber for supplying oil to the second master chamber 20b are provided in the same way, the reservoir 20 is the first master chamber 20a. This is because, when oil is not properly supplied to the , oil cannot be properly supplied to the second master chamber 20b as well.

Accordingly, the reservoir 30 separates the first reservoir chamber 31 and the third reservoir chamber 33 so that the reservoir 30 can be removed even in an emergency when oil cannot be properly supplied to the first master chamber 20a. 2 By normally supplying oil to the master chamber 20b, a normal braking pressure may be formed in at least two wheel cylinders 40 among the four wheel cylinders 40 .

In addition, although not shown in detail, the reservoir 30 is provided by separating the oil lines 116 and 117 connected from the hydraulic pressure supply device 100 to the reservoir 30 and the dump line connected from the wheel cylinder 40 to the reservoir 30 . can do. Accordingly, it is possible to prevent the ABS performance from being deteriorated while the bubbles that may be generated in the dump line do not flow into the first and second pressure chambers 112 and 113 of the hydraulic pressure supply device 100 during ABS braking.

Meanwhile, the simulation device 50 may be connected to a first backup flow path 251 to be described later to provide a reaction force according to the pedal force of the brake pedal 10 . By providing a reaction force that compensates for the pedal force provided by the driver, the driver can fine-tune the braking force as intended.

Referring to FIG. 2 , the simulation device 50 includes a simulation chamber 51 provided to store oil flowing out from the first hydraulic port 24a of the master cylinder 20 and a reaction force piston provided in the simulation chamber 51 ( 52) and a pedal simulator having a reaction force spring 53 elastically supporting it, and a simulator valve 54 connected to the front end of the simulation chamber 51.

The inside of the simulation chamber 51 is always filled with oil. Therefore, when the simulation device 50 is operated, friction of the reaction force piston 52 is minimized, so that durability of the simulation device 50 is improved, and the inflow of foreign substances from the outside can be fundamentally blocked.

The reaction force piston 52 and the reaction force spring 53 are installed to have a displacement within a certain range in the simulation chamber 51 by the oil flowing into the simulation chamber 51 .

The simulator valve 54 may connect the master cylinder 20 and the front end of the simulation chamber 51 , and the rear end of the simulation chamber 51 may be connected to the reservoir 30 . Accordingly, even when the reaction force piston 52 returns, oil flows in from the reservoir 30 so that the entire interior of the simulation chamber 51 can always be filled with oil.

The simulator valve 54 may be configured as a closed solenoid valve that normally maintains a closed state. The simulator valve 54 may be opened when the driver applies a pedal force to the brake pedal 10 to deliver oil in the simulation chamber 51 to the reservoir 30 .

In addition, the simulator check valve 55 may be installed in parallel to the simulator valve 54 . The simulator check valve 55 may ensure a quick return of the pedal simulator pressure when the pedal pressure of the brake pedal 10 is released.

On the other hand, the electronic brake system 1 according to the present embodiment 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 mechanically operates the hydraulic pressure supply device 100 ) and first and second hydraulic circuits 201 and 202 for controlling the flow of hydraulic pressure transmitted to the wheel cylinders 40 provided on the two wheels RR, RL, FR, and FL, respectively. (200) and the first cut valve 261 provided in the first backup flow path 251 connecting the first hydraulic port 24a of the master cylinder and the first hydraulic circuit 201 to control the flow of hydraulic pressure; A second cut valve 262 provided in the second backup flow path 252 connecting the second hydraulic port 24b of the master cylinder and the second hydraulic circuit 202 to control the flow of hydraulic pressure, hydraulic pressure information and pedal displacement Electronic control unit (ECU) for controlling the hydraulic pressure supply device 100 and the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243 based on the information , not shown) may be included.

The hydraulic pressure supply device 100 includes a hydraulic pressure supply unit 110 that provides oil pressure transmitted to the wheel cylinder 40 , a motor 120 that generates a rotational force by an electrical signal of the pedal displacement sensor 11 , and a motor It may include a power conversion unit 130 that converts the rotational motion of the 120 into a linear motion and transmits it to the hydraulic pressure providing unit 110 . Here, the hydraulic pressure providing unit 110 may operate by the pressure provided from the high-pressure accumulator rather than the driving force supplied from the motor 120 .

The hydraulic pressure providing unit 110 will be described below in more detail with reference to FIG. 4 .

The hydraulic pressure providing unit 110 includes a cylinder block 111 in which a pressure chamber for receiving and storing oil is formed, a hydraulic piston 114 accommodated in the cylinder block 111, a hydraulic piston 114 and a cylinder block 111 ) provided between the sealing member (115: 115a, 115b) for sealing the pressure chamber, and a drive shaft connected to the rear end of the hydraulic piston 114 to transmit the power output from the power conversion unit 130 to the hydraulic piston 114 (133).

The pressure chamber is a first pressure chamber 112 positioned in front of the hydraulic piston 114 (in a forward direction, a left direction in the drawing), and a rear (reverse direction, a right direction in the drawing) of the hydraulic piston 114 (reverse direction, a right direction in the drawing). A second pressure chamber 113 may be included.

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 to have a different volume according to the movement of the hydraulic piston 114 , and the second pressure chamber 113 . ) is partitioned by the rear end of the cylinder block 111 and the hydraulic piston 114 , and the volume is provided to vary according to the movement of the hydraulic piston 114 .

The first pressure chamber 112 is connected to the first hydraulic flow passage 211 through the first communication hole 111a formed on the rear side of the cylinder block 111, and the second pressure chamber 113 is the cylinder block ( It is connected to the fourth hydraulic flow path 214 through the second communication hole 111b formed on the front side of the 111 .

The first hydraulic flow path 211 connects the first pressure chamber 112 and the first and second hydraulic circuits 201 and 202 . And the first hydraulic oil passage 211 is branched into a second hydraulic oil passage 212 communicating with the first hydraulic circuit 201 and a third hydraulic oil passage 213 communicating with the second hydraulic circuit 202 . The fourth hydraulic flow path 214 connects the second pressure chamber 113 and the first and second hydraulic circuits 201 and 202 . And the fourth hydraulic oil passage 214 is branched into a fifth hydraulic oil passage 215 communicating with the first hydraulic circuit 201 and a sixth hydraulic oil passage 216 communicating with the second hydraulic circuit 202 .

The sealing member 115 is provided between the hydraulic piston 114 and the cylinder block 111 to seal the first pressure chamber 112 and the second pressure chamber 113 between the piston sealing member 115a 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). That is, the hydraulic pressure or negative pressure of the first pressure chamber 112 generated by the forward or backward movement of the hydraulic piston 114 is blocked by the piston sealing member 115a and does not leak into the second pressure chamber 113. and the fourth hydraulic flow passages 211 and 214 . In addition, the hydraulic pressure or negative pressure of the second pressure chamber 113 generated by the forward or backward movement of the hydraulic piston 114 may be blocked by the drive shaft sealing member 115b so as not to leak into the cylinder block 111 .

The first and second pressure chambers 112 and 113 are respectively connected to the reservoir 30 by the dump passages 116 and 117, and receive and store oil from the reservoir 30, or the first or second pressure chamber ( Oils 112 and 113 may be transferred to the reservoir 30 . For example, the first pressure chamber 112 is connected to the first dump passage 116 through the third communication hole 111c formed on the front side, and the second pressure chamber 113 is formed on the rear side. 4 may be connected to the second dump passage 117 through the communication hole 111d.

Referring again to FIG. 2 , flow paths 211 , 212 , 213 , 214 , 215 , 216 , 217 and valves 231 , 232 connected to the first pressure chamber 112 and the second pressure chamber 113 , 233, 234, 235, 236, 241, 242, 243) will be described.

The second hydraulic oil passage 212 may communicate with the first hydraulic circuit 201 , and the third hydraulic oil passage 213 may communicate with the second hydraulic circuit 202 . Accordingly, hydraulic pressure may be transmitted to the first hydraulic circuit 201 and the second hydraulic circuit 202 by the advance of the hydraulic piston 114 .

In addition, the electromagnetic brake system 1 according to the present embodiment is provided in the second and third hydraulic oil passages 212 and 213, respectively, and a first control valve 231 and a second control valve 232 for controlling the flow of oil. may include

The first and second control valves 231 and 232 allow only the oil flow in the direction from the first pressure chamber 112 to the first or second hydraulic circuit 201, 202, and the oil flow in the opposite direction is It may be provided as a check valve to shut off. That is, the first or second control valves 231 and 232 allow the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first or second hydraulic circuits 201 and 202 while allowing the first or second hydraulic pressure to be transferred. It is possible to prevent the hydraulic pressure of the circuits 201 and 202 from leaking into the first pressure chamber 112 through the second or third hydraulic passages 212 and 213 .

The fourth hydraulic oil passage 213 may be branched into a fifth hydraulic oil passage 215 and a sixth hydraulic oil passage 216 on the way to communicate with both the first hydraulic circuit 201 and the second hydraulic circuit 202 . For example, the fifth hydraulic oil passage 215 branched from the fourth hydraulic oil passage 214 communicates with the first hydraulic circuit 201 , and the sixth hydraulic oil passage 216 branched from the fourth hydraulic oil passage 214 is It may communicate with the second hydraulic circuit 202 . Accordingly, hydraulic pressure may be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 by the backward movement of the hydraulic piston 114 .

In addition, the electromagnetic brake system 1 according to the present embodiment is provided in the third control valve 233 and the sixth hydraulic flow path 216 provided in the fifth hydraulic flow path 215 to control the flow of oil to control the flow of oil. It may include a fourth control valve 234 to control.

The third control valve 233 may be provided as a bidirectional control valve for controlling the oil flow between the second pressure chamber 113 and the first hydraulic circuit 201 . The third control valve 233 may be provided as a normally closed type solenoid valve that is normally closed and operates to open when an open signal is received from the electronic control unit.

The fourth control valve 234 may be provided as a check valve that allows only the oil flow in the direction from the second pressure chamber 113 to the second hydraulic circuit 202 and blocks the oil flow in the opposite direction. That is, the fourth control valve 234 prevents the hydraulic pressure of the second hydraulic circuit 202 from leaking into the second pressure chamber 113 through the sixth hydraulic oil passage 216 and the fourth hydraulic oil passage 214 . can

In addition, the electromagnetic brake system 1 according to the present embodiment is provided in the seventh hydraulic oil passage 217 connecting the second hydraulic oil passage 212 and the third hydraulic oil passage 213 to a fifth control for controlling the flow of oil. It may include a valve 235 and a sixth control valve 236 provided in the eighth hydraulic passage 218 connecting the second hydraulic passage 212 and the seventh hydraulic passage 217 to control the flow of oil. there is. The fifth control valve 235 and the sixth control valve 236 may be provided as normally closed solenoid valves that operate to open when an open signal is received from the electronic control unit after being normally closed. .

When an abnormality occurs in the first control valve 231 or the second control valve 232 , the fifth control valve 235 and the sixth control valve 236 operate to open the first pressure chamber 112 . The hydraulic pressure may be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 .

In addition, the fifth control valve 235 and the sixth control valve 236 may operate to open when the hydraulic pressure of the wheel cylinder 40 is drawn out and sent to the first pressure chamber 112 . This is because the first control valve 231 and the second control valve 232 provided in the second hydraulic passage 212 and the third hydraulic passage 213 are provided as check valves allowing only one-way oil flow.

On the other hand, in the electromagnetic brake system 1 according to the present embodiment, a first dump valve 241 and a second dump valve 242 are provided in the first and second dump passages 116 and 117, respectively, to control the flow of oil. ) may be further included. The dump valves 241 and 242 may be check valves that open only a direction from the reservoir 30 to the first or second pressure chambers 112 and 113 and close in the opposite direction.

That is, the first dump valve 241 allows oil to flow from the reservoir 30 to the first pressure chamber 112, but blocks the flow of oil from the first pressure chamber 112 to the reservoir 30. It may be a check valve, and the second dump valve 242 allows oil to flow from the reservoir 30 to the second pressure chamber 113 , but the oil flows from the second pressure chamber 113 to the reservoir 30 . The flow may be a check valve shutting off.

The second dump flow path 117 may include a bypass flow path, and the third dump valve 243 for controlling the oil flow between the second pressure chamber 113 and the reservoir 30 is installed in the bypass flow path. can

The third dump valve 243 may be provided as a solenoid valve capable of controlling the flow in both directions. The third dump valve 243 may be provided as a normally open type solenoid valve that is opened in a normal state and operates to close when a closing signal is received from the electronic control unit.

Here, the hydraulic pressure providing unit 110 of the electromagnetic brake system 1 according to the present embodiment may operate in a double-acting manner. That is, the hydraulic pressure generated in the first pressure chamber 112 as the hydraulic piston 114 advances is transmitted to the first hydraulic circuit 201 through the first hydraulic oil passage 211 and the second hydraulic oil passage 212 to the right side. The wheel cylinder 40 installed on the rear wheel RR and the left rear wheel LR can act, and it is transmitted to the second hydraulic circuit 202 through the first hydraulic oil passage 211 and the third hydraulic oil passage 213 . and the wheel cylinder 40 installed on the right front wheel FR and the left front wheel FL can act.

Similarly, the hydraulic pressure generated in the second pressure chamber 113 while the hydraulic piston 114 moves backward is transmitted to the first hydraulic circuit 201 through the fourth hydraulic passage 214 and the fifth hydraulic passage 215 to the right The wheel cylinder 40 installed on the rear wheel RR and the left rear wheel RL can act, and it is transmitted to the second hydraulic circuit 202 through the fourth hydraulic oil passage 214 and the sixth hydraulic oil passage 216 . and the wheel cylinder 40 installed on the right front wheel FR and the left front wheel FL can act.

In addition, the negative pressure generated in the first pressure chamber 112 while the hydraulic piston 114 moves backward is applied to the wheel cylinder 40 installed in the right rear wheel RR and the left rear wheel RL of the first hydraulic circuit 201 . Oil may be sucked and delivered to the first pressure chamber 112 through the second hydraulic flow path 212 and the first hydraulic flow path 211 , and the right front wheel FR and the left front wheel of the second hydraulic circuit 202 . Oil of the wheel cylinder 40 installed in the FL may be sucked and transferred to the first pressure chamber 112 through the third hydraulic flow path 213 and the first hydraulic flow path 211 .

Similarly, the hydraulic pressure generated in the second pressure chamber 113 as the hydraulic piston 114 advances transfers the oil of each wheel cylinder 40 of the first hydraulic circuit 201 and the second hydraulic circuit 202 to the hydraulic flow path ( 215 and 214 may be sucked in and delivered to the second pressure chamber 113 .

Meanwhile, according to the present embodiment, a regenerative control valve 239 may be provided on the hydraulic flow path connecting the hydraulic pressure supply device 100 and the hydraulic control unit 200 . The regenerative control valve 239 may be provided as a normal open type solenoid valve that is normally open and operates to close the valve when a closing signal is received from the electronic control unit.

The regenerative control valve 239 is transmitted from the hydraulic pressure supply device 100 to the hydraulic control unit 200 according to the regenerative braking force generated during deceleration in a vehicle that generates rotational driving force to the wheel by a motor, such as a hybrid vehicle or an electric vehicle. It is used to reduce the hydraulic braking force. In this embodiment, as described above, rather than the second hydraulic circuit 202 connected to the wheel cylinders 40 of the front wheels (FR, FL) to increase the braking stability of the vehicle, the wheel cylinders 40 of the rear wheels (RR, RL) It is provided on the hydraulic flow path connected to the first hydraulic circuit 201 connected to. A detailed control operation will be described later.

Next, the motor 120 and the power conversion unit 130 of the hydraulic pressure supply device 100 will be described.

The motor 120 is a device for generating a rotational force by a signal output from an electronic control unit (ECU, not shown), and may generate a rotational force in a forward or reverse direction. The rotation angular speed and rotation angle of the motor 120 may be precisely controlled. Since the motor 120 is a well-known technology, a detailed description thereof will be omitted.

The electronic control unit includes the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243). An operation in which the plurality of valves are controlled according to the displacement of the brake pedal 10 will be described later.

The driving force of the motor 120 generates displacement of the hydraulic piston 114 through the power conversion unit 130, and the hydraulic pressure generated while the hydraulic piston 114 slides within the pressure chamber is generated by the hydraulic flow passages 211 and 214. It is transmitted to the wheel cylinder 40 installed in each wheel (RR, RL, FR, FL) through. The motor may employ a brushless motor including a stator 121 and a rotor 122 .

The power conversion unit 130 is a device that converts rotational force into linear motion, and may include, for example, a worm shaft 131 , a worm wheel 132 , and a drive shaft 133 .

The worm shaft 131 may be integrally formed with the rotation shaft of the motor 120 , and a worm is formed on the outer peripheral surface to engage the worm wheel 132 to rotate the worm wheel 132 . The worm wheel 132 is connected to engage the drive shaft 133 to linearly move the drive shaft 133 , and the drive shaft 133 is connected to the hydraulic piston 114 to slide the hydraulic piston 114 in the cylinder block 111 . move

When the above operations are described again, a signal sensed by the pedal displacement sensor 11 while displacement occurs in the brake pedal 10 is transmitted to an electronic control unit (ECU, not shown), and the electronic control unit is a motor 120 . is driven in one direction to rotate the worm shaft 131 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 to generate hydraulic pressure in the first pressure chamber 112 .

Conversely, when the pedal force is removed from the brake pedal 10 , the electronic control unit drives the motor 120 in the opposite direction to rotate the worm shaft 131 in the opposite direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and the hydraulic piston 114 connected to the drive shaft 133 returns (moves backward) to generate negative pressure in the first pressure chamber 112 .

On the other hand, the generation of hydraulic pressure and negative pressure is also possible in the direction opposite to the above. That is, while displacement occurs in the brake pedal 10 , the signal sensed by the pedal displacement sensor 11 is transmitted to an electronic control unit (ECU, not shown), and the electronic control unit drives the motor 120 in the opposite direction. to rotate the worm shaft 131 in the opposite 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 backward to generate hydraulic pressure in the second pressure chamber 113 .

Conversely, when the pedal force is removed from the brake pedal 10 , the electronic control unit drives the motor 120 in one direction to rotate the worm shaft 131 in one direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and the hydraulic piston 114 connected to the drive shaft 133 returns (moves forward) to generate a negative pressure in the second pressure chamber 113 .

As such, the hydraulic pressure supply device 100 serves to transmit the hydraulic pressure to the wheel cylinder 40 or suck the hydraulic pressure to the reservoir 30 according to the rotation direction of the rotational force generated from the motor 120 . For example, when the motor 120 rotates in one direction, hydraulic pressure may be generated in the first pressure chamber 112 or negative pressure may be generated in the second pressure chamber 113 . Whether to brake using hydraulic pressure or using negative pressure Whether to release the brake may be determined by controlling the valves 54 , 60 , 221a , 221b , 221c , 221d , 222a , 222b , 222c , 222d , 233 , 235 , 236 , and 243 .

Meanwhile, in the electronic brake system 1 according to the present embodiment, the first and second backup flow paths 251 and 252 capable of supplying the oil discharged from the master cylinder 20 directly to the wheel cylinder 40 when operating abnormally. ) may be further included.

The first backup passage 251 connects the first hydraulic port 24a and the first hydraulic circuit 201 , and the second backup passage 252 is the second hydraulic port 24b and the second hydraulic circuit 202 . can be connected In addition, a first cut valve 261 for controlling the flow of oil is provided in the first backup passage 251 , and a second cut valve 262 for controlling the flow of oil is provided in the second backup passage 252 . can be

The first and second cut valves 261 and 262 may be provided as normal open type solenoid valves that are opened in a normal state and operate to close the valves when a closing signal is received from the electronic control unit. .

Next, the hydraulic control unit 200 according to an embodiment of the present invention will be described.

The hydraulic control unit 200 may include a first hydraulic circuit 201 and a second hydraulic circuit 202 so as to receive hydraulic pressure to allocate and control two wheels, respectively. For example, the first hydraulic circuit 201 may control the right rear wheel RR and the left rear wheel RL, and the second hydraulic circuit 202 may control the right front wheel FR and the left front wheel FL. . A wheel cylinder 40 is installed on each of the wheels FR, FL, RR, and RL to receive hydraulic pressure from the hydraulic pressure supply device 100 to perform braking.

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 pressure passage 212 is connected to the right rear wheel RR ) and the left rear wheel (RL). 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 the right front wheel. It is branched into two flow paths connected to (FR) and the left front wheel (FL). The fifth hydraulic oil passage 215 connected to the second hydraulic oil passage 212 and the sixth hydraulic oil passage 216 connected to the third hydraulic oil passage 213 are also branched and connected to each wheel cylinder 40 .

The first and second hydraulic circuits 201 and 202 may include a plurality of inlet valves 221 (221a, 221b, 221c, 221d) to control the flow of hydraulic pressure. For example, the first hydraulic circuit 201 may be provided with two inlet valves 221a and 221b connected to the first hydraulic flow path 211 to respectively control the hydraulic pressure transmitted to the two wheel cylinders 40 . . In addition, the second hydraulic circuit 202 may be provided with two inlet valves 221c and 221d connected to the third hydraulic flow path 213 to respectively control the hydraulic pressure transmitted to the wheel cylinder 40 . Here, the inlet valve 221 is disposed on the upstream side of the wheel cylinder 40, is open in a normal state, and is a normally open type solenoid that operates to close the valve when a closing signal is received from the electronic control unit. It may be provided as a valve.

In addition, the hydraulic circuits 201 and 202 may include check valves 223a, 223b, 223c, 223d provided in the bypass flow path connecting the front and rear of each inlet valve 221a, 221b, 221c, 221d. can The check valves 223a, 223b, 223c, and 223d allow only the flow of oil from the wheel cylinder 40 to the hydraulic pressure providing unit 110 in the direction, and from the hydraulic pressure providing unit 110 to the wheel cylinder 40 direction. The flow of can be provided to limit. The check valves 223a, 223b, 223c, and 223d can quickly release the braking pressure of the wheel cylinder 40, and when the inlet valves 221a, 221b, 221c, and 221d do not operate normally, the wheel cylinder The hydraulic pressure of 40 may be introduced into the hydraulic pressure providing unit 110 .

In addition, the hydraulic circuits 201 and 202 may further include a plurality of outlet valves 222 (222a, 222b, 222c, 222d) connected to the reservoir 30 to improve performance when braking is released. The outlet valve 222 is connected to the wheel cylinder 40, respectively, and controls the hydraulic pressure to escape from the respective wheels RR, RL, FR, and FL. That is, the outlet valve 222 detects the braking pressure of each of the wheels RR, RL, FR, and FL and selectively opens when pressure reduction braking is required to control the pressure. The outlet valve 222 may be provided as a normally closed type solenoid valve that is normally closed and operates to open when an open signal is received from the electronic control unit.

Meanwhile, the hydraulic control unit 200 may be connected to the backup flow paths 251 and 252 . For example, the first hydraulic circuit 201 is connected to the first backup passage 251 to receive hydraulic pressure from the master cylinder 20 , and the second hydraulic circuit 202 is connected to the second backup passage 252 , Hydraulic pressure may be provided from the master cylinder 20 .

The first backup flow passage 251 may join the first hydraulic circuit 201 upstream of the first and second inlet valves 221a and 221b. Similarly, the second backup flow path 252 may join the second hydraulic circuit 202 upstream of the third and fourth inlet valves 221c and 221d. Therefore, when the first and second cut valves 261 and 262 are closed, the hydraulic pressure provided from the hydraulic pressure supply device 100 is supplied to the wheel cylinder 40 through the first and second hydraulic circuits 201 and 202. When the first and second cut valves 261 and 262 are opened, the hydraulic pressure provided from the master cylinder 20 is supplied to the wheel cylinder 40 through the first and second backup passages 251 and 252. can At this time, since the plurality of inlet valves 221a, 221b, 221c, and 221d maintain an open state, it is not necessary to change the operating state. In addition, the first backup flow path 251 may be provided upstream as well as downstream of the regenerative control valve 239 as shown. This is because the backup flow path is used when the hydraulic pressure supply device 100 is in an abnormal operation, and in this case, braking is performed regardless of the regenerative braking force.

On the other hand, unexplained reference numerals "PS1-1" and "PS1-2" are hydraulic pressure sensors for sensing the hydraulic pressure of the first and second hydraulic circuits 201 and 202, and "PS2" is the master cylinder 20. It is a backup oil pressure sensor that measures the oil pressure of And “MPS” is a motor control sensor that controls the rotation angle of the motor 120 or the current of the motor.

Then, the operation of the electronic brake system 1 according to an embodiment of the present invention will be described in detail below.

Prior to the description, the hydraulic pressure supply device 100 is The low-pressure mode and the high-pressure mode can be used separately. The low pressure mode and the high pressure mode may be changed by different operations of the hydraulic control unit 200 . The hydraulic pressure supply device 100 may generate a high hydraulic pressure without increasing the output of the motor 120 by using the high pressure mode. Therefore, it is possible to guarantee stable braking power while lowering the price and weight of the brake system.

In more detail, the hydraulic piston 114 generates hydraulic pressure in the first pressure chamber 112 while advancing. As the hydraulic piston 114 advances from the initial state, that is, as the stroke of the hydraulic piston 114 increases, the amount of oil transferred from the first pressure chamber 112 to the wheel cylinder 40 increases and the braking pressure rises. do. However, since there is an effective stroke of the hydraulic piston 114 there is a maximum pressure due to the advance of the hydraulic piston 114 .

The maximum pressure in the low pressure mode is smaller than the maximum pressure in 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 oil pushed out from the first pressure chamber 112 flows into the wheel cylinder 40 , but a part flows into the second pressure chamber 113 .

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

When braking by the driver starts, the electronic brake system 1 according to the present embodiment can detect the required braking force of the driver through information such as the pressure of the brake pedal 10 that the driver steps on through the pedal displacement sensor 11 . there is.

That is, the electronic control unit (not shown) receives the electrical signal output from the pedal displacement sensor 11 to drive the motor 120 , and the rotational force of the motor 120 is provided by the power conversion unit 130 to the hydraulic pressure providing unit It is transmitted to 110 , and the hydraulic pressure providing unit 110 generates hydraulic pressure in the first pressure chamber 112 while the hydraulic piston 114 advances. The hydraulic pressure discharged from the hydraulic pressure supply unit 110 is transmitted to the wheel cylinders 40 provided in each of the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate braking force.

Meanwhile, the electronic control unit determines whether regenerative braking force is generated in the vehicle as shown in FIG. 5 ( 310 ). When the regenerative braking force is not generated, the hydraulic pressure supply device 100 is normally operated to generate a uniform braking force on the four wheels ( 320 ).

When it is determined that regenerative braking force is generated in the rear wheels (RR, RL), the electronic control unit calculates the required hydraulic braking force according to the difference between the driver's required braking force and the regenerative braking force (330), and according to the hydraulic pressure, the regenerative control valve ( 239) to control the opening and closing (340). The hydraulic braking force of the rear wheel in which the regenerative braking force is generated is generally reduced than the hydraulic braking force in the case in which the regenerative braking force is not generated.

In addition, when the hydraulic oil pressure sensors PS1-1 and PS1-2 respectively provided in the first hydraulic circuit 201 and the second hydraulic circuit 202 are used as described above, the wheel cylinder ( 40) can be controlled more stably. That is, the electronic control unit detects hydraulic braking force transmitted from the hydraulic pressure supply device 100 to the first hydraulic circuit 201 and the second hydraulic circuit 202 , respectively. And, when regenerative braking force is generated, the required hydraulic braking force is calculated and transmitted to the wheel cylinder. At this time, if the regenerative control valve 239 is installed in the first hydraulic circuit 201 as in this embodiment, the regenerative control valve ( The hydraulic pressure transmitted to the first hydraulic circuit 201 may be adjusted based on the second hydraulic circuit 202 in which the 239 is not installed. For stable braking, the sum of the hydraulic braking force and regenerative braking force transmitted to the first hydraulic circuit 201 is at least equal to or smaller than the hydraulic braking force transmitted to the second hydraulic circuit 202 .

Hereinafter, a general braking operation using the electronic brake system 1 will be described once again. For example, in the vehicle to which the regenerative braking force acts, the hydraulic braking force transmitted from the hydraulic pressure supply device 100 to the hydraulic circuits 201 and 202 of the hydraulic control unit 200 is different as described above, but finally, the wheel cylinder ( This is because the hydraulic pressure delivered to 40) is the same.

At the beginning of braking, when the driver steps on the brake pedal 10, the motor 120 rotates in one direction, and the rotational force of the motor 120 is transmitted to the hydraulic pressure providing unit 110 by the power conversion unit 130, The hydraulic pressure providing unit 110 generates hydraulic pressure in the first pressure chamber 112 while the hydraulic piston 114 advances. The hydraulic pressure discharged from the hydraulic pressure supply unit 110 is transmitted to the wheel cylinders 40 provided in 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 first pressure chamber 112 is applied to the two wheels RR and RL through the first hydraulic passage 211 and the second hydraulic passage 212 connected to the first communication hole 111a. It is directly transmitted to the wheel cylinder 40 provided in the. At this time, the first and second inlet valves 221a and 221b respectively installed in two flow passages branching from the second hydraulic flow passage 212 are provided in an open state. In addition, the first and second outlet valves 222a and 222b installed in the flow passages respectively branching from the two oil passages branching from the second hydraulic oil passage 212 are maintained in a closed state to prevent the hydraulic pressure from leaking to the reservoir 30 . block

In addition, the hydraulic pressure provided from the first pressure chamber 112 is applied to the two wheels FR and FL through the first hydraulic passage 211 and the third hydraulic passage 213 connected to the first communication hole 111a. It is directly transmitted to the wheel cylinder 40 provided. At this time, the third and fourth inlet valves 221c and 221d respectively installed in two flow passages branching from the third hydraulic flow passage 213 are provided in an open state. In addition, the third and fourth outlet valves 222c and 222d installed in the flow paths branching from the two flow paths branching from the third hydraulic flow path 213 are maintained in a closed state to prevent the hydraulic pressure from leaking to the reservoir 30 . block

At this time, the fifth control valve 235 and the sixth control valve 236 may be switched to an open state to open the seventh hydraulic oil passage 217 and the eighth hydraulic oil passage 218 . As the seventh hydraulic oil passage 217 and the eighth hydraulic oil passage 218 are opened, the second hydraulic oil passage 212 and the third hydraulic oil passage 213 communicate with each other. Here, if necessary, any one or more of the fifth control valve 235 and the sixth control valve 236 may be maintained in a closed state.

In addition, at this time, the third control valve 233 may be maintained in a closed state to block the fifth hydraulic flow path 215 . By preventing the hydraulic pressure generated in the first pressure chamber 112 from being transmitted to the second pressure chamber 113 through the fifth hydraulic passage 215 connected to the second hydraulic passage 212, the pressure increase rate per stroke can be improved. there is. Therefore, a quick braking response can be expected at the beginning of braking.

In addition, when the pressure transmitted to the wheel cylinder 40 is measured to be higher than the target pressure value according to the pedal effort of the brake pedal 10, any one or more of the first to fourth outlet valves 222 is opened to the target. It can be controlled to follow the pressure value.

In addition, the first and second backup passages 251 and 252 connected to the first and second hydraulic ports 24a and 24b of the master cylinder 20 when hydraulic pressure is generated in the hydraulic pressure supply device 100 are first and second The second cut valves 261 and 262 are closed so that hydraulic pressure discharged from the master cylinder 20 is not transmitted to the wheel cylinder 40 .

The pressure generated according to the pressurization of the master cylinder 20 according to the pedaling force of the brake pedal 10 is transmitted to the simulation device 50 connected to the master cylinder 20 . At this time, the normally closed simulator valve 54 disposed at the front end of the simulation chamber 51 is opened, and the oil filled in the simulation chamber 51 is transferred to the reservoir 30 through the simulator valve 54 . In addition, the reaction force piston 52 moves and a pressure corresponding to the load of the reaction force spring 53 supporting the reaction force piston 52 is formed in the simulation chamber 51 to provide an appropriate pedal feeling to the driver.

The hydraulic flow pressure sensor PS1-2 or PS1-1 may detect a flow rate transmitted to the wheel cylinder 40 installed on the front wheel or the rear wheel. Accordingly, by controlling the hydraulic pressure supply device 100 according to the output of the hydraulic oil pressure sensor PS1-2, the flow rate transmitted to the wheel cylinder 40 can be controlled. Specifically, the flow rate and discharge speed discharged from the wheel cylinder 40 may be controlled by adjusting the forward distance and forward speed of the hydraulic piston 114 .

On the other hand, before the hydraulic piston 114 advances to the maximum, it can be switched from the low pressure mode to the high pressure mode.

In the high pressure mode, the third control valve 233 may be switched to an open state to open the fifth hydraulic flow path 215 . Therefore, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the second pressure chamber 113 through the fifth hydraulic passage 215 connected to the second hydraulic passage 212 to push the hydraulic piston 114 . can be used

In the high pressure mode, since a part of the oil pushed out from the first pressure chamber 112 flows into the second pressure chamber 113 , the pressure increase rate per stroke decreases. However, since a part of the hydraulic pressure generated in the first pressure chamber 112 is used to push the hydraulic piston 114, the maximum pressure increases. At this time, the reason that the maximum pressure increases is because the volume per stroke of the hydraulic piston 114 of the second pressure chamber 113 is smaller than the volume per stroke of the hydraulic piston 114 of the first pressure chamber 112 .

Next, a case in which the braking force is released in a braking state during normal operation of the electronic brake system 1 according to the present embodiment will be described.

When the pedal force applied to the brake pedal 10 is released, the motor 120 generates a rotational force in the opposite direction during braking and transmits it to the power conversion unit 130 , and the worm shaft 131 and the worm wheel of the power conversion unit 130 . 132 and the driving shaft 133 rotate in the opposite direction during braking to retract the hydraulic piston 114 to its original position, thereby releasing the pressure in the first pressure chamber 112 or generating negative pressure. In addition, the hydraulic pressure providing unit 110 receives the hydraulic pressure discharged from the wheel cylinder 40 through the first and second hydraulic circuits 201 and 202 and transmits it to the first pressure chamber 112 .

Specifically, the negative pressure generated in the first pressure chamber 112 is applied to the two wheels RR and RL through the first hydraulic passage 211 and the second hydraulic passage 212 connected to the first communication hole 111a. Release the pressure of the wheel cylinder 40 provided in the. At this time, the first and second inlet valves 221a and 221b respectively installed in two flow passages branching from the second hydraulic flow passage 212 are provided in an open state. In addition, the first and second outlet valves 222a and 222b installed in the flow passages respectively branching from the two oil passages branching from the second hydraulic oil passage 212 are maintained in a closed state to prevent the oil from the reservoir 30 from flowing in. block

And the negative pressure generated in the first pressure chamber 112 is provided on the two wheels FR and FL through the first hydraulic passage 211 and the third hydraulic passage 213 connected to the first communication hole 111a. Release the pressure of the wheel cylinder (40). At this time, the third and fourth inlet valves 221c and 221d respectively installed in two flow passages branching from the third hydraulic flow passage 213 are provided in an open state. In addition, the third and fourth outlet valves 222c and 222d installed in the flow paths branching from the two flow paths branching from the third hydraulic flow path 213 are maintained in a closed state to prevent the inflow of oil from the reservoir 30 . block

And the third control valve 233 is switched to the open state to open the fifth hydraulic flow path 215 , and the fifth control valve 235 is switched to the open state to open the seventh hydraulic flow path 217 and a sixth The control valve 236 may be switched to an open state to open the eighth hydraulic flow path 218 . Accordingly, the first pressure chamber 112 and the second pressure chamber 113 communicate with each other while the fifth hydraulic passage 215, the seventh hydraulic passage 217, and the eighth hydraulic oil passage 218 are connected.

In order for the negative pressure to be formed in the first pressure chamber 112 , the hydraulic piston 114 must move backward. When the second pressure chamber 113 is full of oil, resistance occurs when the hydraulic piston 114 moves backward. Accordingly, the third control valve 233 , the fifth control valve 235 , and the sixth control valve 236 are opened so that the fourth hydraulic oil passage 214 and the fifth hydraulic oil passage 215 are connected to the second hydraulic oil passage 212 . ) and the first hydraulic flow passage 211 , the oil in the second pressure chamber 113 moves to the first pressure chamber 112 .

The third dump valve 243 may be switched to a closed state. As the third dump valve 243 is closed, the oil in the second pressure chamber 113 may be discharged only through the fourth hydraulic flow path 214 . However, in some cases, the oil in the second pressure chamber 113 may be introduced into the reservoir 30 because the third dump valve 243 is maintained in an open state.

In addition, when the negative pressure transferred to the first and second hydraulic circuits 201 and 202 is measured to be higher than the target pressure release value according to the release amount of the brake pedal 10 , the first to fourth outlet valves 222 . By opening at least one of them, it is possible to control to follow the target pressure value.

On the other hand, the first and second backup passages 251 and 252 connected to the first and second hydraulic ports 24a and 24b of the master cylinder 20 when hydraulic pressure is generated in the hydraulic pressure supply device 100 are first and second The second cut valves 261 and 262 are closed so that the negative pressure generated in the master cylinder 20 is not transmitted to the hydraulic control unit 200 .

In the high-pressure mode, the oil in the second pressure chamber 113 together with the oil in the wheel cylinder 40 due to the negative pressure in the first pressure chamber 112 generated while the hydraulic piston 114 moves backwards into the first pressure chamber 112 . Because it moves to , the pressure reduction rate of the wheel cylinder 40 is small. Therefore, it may be difficult to quickly release the pressure in the high pressure mode.

For this reason, the high-pressure mode can be used only in a high-pressure situation, and when the pressure is lowered to a certain level or less, the low-pressure mode can be switched.

In the above embodiment, the hydraulic pressure and negative pressure generating operation when the hydraulic piston 114 moves forward has been exemplified as an example, but the present invention is not limited thereto. For example, even when the hydraulic piston 114 is retracted, the operation may be controlled so that hydraulic pressure and negative pressure are respectively generated in the first pressure chamber 112 and the second pressure chamber 113 .

In addition, although the operation of the electronic brake system in which braking and braking is normally released has been exemplified above, the present invention is not limited thereto, and a person skilled in the art can appropriately perform braking operations in abnormal conditions or ABS mode, inspection mode, and dump mode. Of course, it can be used with variations and modifications.

6 is a view showing a hydraulic pressure supply device of an electronic brake system according to another embodiment of the present invention. The present embodiment will be described with a focus on the points different from the above embodiment, and the same reference numerals perform the same functions, and thus detailed descriptions thereof will be omitted.

The hydraulic pressure supply device 100 ′ according to the present embodiment includes a hydraulic pressure supply unit 110 that provides oil pressure transferred to a wheel cylinder 40 , and a motor that generates a rotational force by an electrical signal from the pedal displacement sensor 11 . It may include 120 and a power conversion unit 130 that converts the rotational motion of the motor 120 into a linear motion and transmits it to the hydraulic pressure providing unit 110 .

The hydraulic pressure providing unit 110 includes a cylinder block 111 in which a pressure chamber for receiving and storing oil is formed, a hydraulic piston 114 accommodated in the cylinder block 111, a hydraulic piston 114 and a cylinder block 111 ) provided between the sealing member 115 for sealing the pressure chamber, and the driving shaft 133 connected to the rear end of the hydraulic piston 114 to transmit the power output from the power conversion unit 130 to the hydraulic piston 114. include

The pressure chamber may include a first pressure chamber 112 positioned in front of the hydraulic piston 114 and a second pressure chamber 113 positioned in the rear of the hydraulic piston 114 .

The first pressure chamber 112 is connected to the first hydraulic flow passage 211 through the first communication hole 111a formed on the rear side of the cylinder block 111, and is formed on the front side of the cylinder block 111. It is connected to the fourth hydraulic flow passage 214 through the second communication hole 111b. The first hydraulic flow path 211 connects the first pressure chamber 112 and the first and second hydraulic circuits 201 and 202 . The fourth hydraulic flow path 214 connects the second pressure chamber 113 and the first and second hydraulic circuits 201 and 202 .

In addition, the first and second pressure chambers 112 and 113 are respectively connected to the reservoir 30 by the dump passages 116 and 117 to receive and store oil supplied from the reservoir 30 or to store the first or second pressure. The oil in the chambers 112 and 113 may be transferred to the reservoir 30 .

The second hydraulic oil passage 212 branching from the first hydraulic oil passage 211 may communicate with the first hydraulic circuit 201 , and the third hydraulic oil passage 213 may communicate with the second hydraulic circuit 202 . In addition, a first control valve 231 and a second control valve 232 for controlling the flow of oil may be provided in the second and third hydraulic passages 212 and 213 , respectively. The first and second control valves 231 and 232 allow only the oil flow in the direction from the first pressure chamber 112 to the first or second hydraulic circuit 201, 202, and the oil flow in the opposite direction is It may be provided as a check valve to shut off.

The fifth hydraulic oil passage 215 branched from the fourth hydraulic oil passage 214 may communicate with the first hydraulic circuit 201 , and the sixth hydraulic oil passage 216 may communicate with the second hydraulic circuit 202 . In addition, a third control valve 233 ′ and a fourth control valve 234 for controlling the flow of oil may be provided in the fifth and sixth hydraulic passages 215 and 216 , respectively. The third and fourth control valves 233' and 234 allow only the oil flow in the direction from the second pressure chamber 113 to the first or second hydraulic circuit 201, 202, and the oil flow in the opposite direction. may be provided as a check valve to shut off.

The first to fourth control valves 231,232,233', 234 provided in the form of a check valve as described above can supply hydraulic pressure from the hydraulic pressure supply unit 110 to the wheel cylinder 40, but reduce pressure to the wheel cylinder 40 When this is necessary, the fluid does not move even if a negative pressure is generated in the hydraulic pressure providing unit 110 . Accordingly, in such an electronic brake system, pressure reduction control of the wheel cylinder 40 can be performed using the outlet valves 222: 222a, 222b, 222c, and 222d.

Although the configuration of the hydraulic pressure supply device 100 ′ of the electronic brake system according to the present embodiment is different from the first embodiment, cooperative control of the hydraulic braking force and the regenerative braking force using the regenerative control valve 239 is substantially the same. omit

10: brake pedal 11: pedal displacement sensor
20: master cylinder 30: reservoir
31-33: reservoir chamber 34, 35: bulkhead
40: wheel cylinder 50: simulation device
54: simulator valve 60: inspection valve
100,100': hydraulic pressure supply device 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 flow path
212: second hydraulic flow path 213: third hydraulic flow path
214: fourth hydraulic flow path 215: fifth hydraulic flow path
216: 6th hydraulic flow path 217: 7th hydraulic flow path
218: eighth hydraulic flow path 221: inlet valve
222: outlet valve 223: check valve
231: first control valve 232: second control valve
233,233': third control valve 234: fourth control valve
235: fifth control valve 236: sixth control valve
239: regenerative control valve
241: first dump valve 242: second dump valve
243: third dump valve 251: first backup flow path
252: second backup flow path 261: first cut valve
262: second cut valve PS1-1: first hydraulic oil pressure sensor
PS1-2: Second hydraulic oil pressure sensor MPS: Motor control sensor

Claims (11)

a reservoir in which oil is stored;
a master cylinder connected to the reservoir and having first and second master chambers and first and second pistons provided in each master chamber to discharge oil according to a pedal effort of the brake pedal;
a hydraulic pressure supply device that operates by an electrical signal to generate hydraulic pressure;
a hydraulic control unit separated into a first hydraulic circuit connected to the rear wheel and a second hydraulic circuit connected to the front wheel to transmit the hydraulic pressure discharged from the hydraulic pressure supply device to the wheel cylinders respectively provided on the two wheels; and
A regenerative control valve that is provided in the hydraulic flow path connecting the hydraulic pressure supply device and the first hydraulic circuit and opens and closes to reduce the hydraulic braking force transmitted to the first hydraulic circuit in response to the regenerative braking force generated in the rear wheel when the regenerative braking force is generated; Electronic brake system included. The method of claim 1,
The hydraulic braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit and the second hydraulic circuit is different according to the opening and closing of the regenerative control valve. 3. The method of claim 2,
A first hydraulic flow path pressure sensor for sensing the hydraulic pressure of the first hydraulic circuit, and a second hydraulic path pressure sensor for sensing the hydraulic pressure of the second hydraulic circuit,
The regenerative control valve opens and closes control so that the hydraulic pressures sensed by the first hydraulic pressure sensor and the second hydraulic pressure sensor are at least the same or the hydraulic pressure of the first hydraulic pressure sensor is smaller than the hydraulic pressure of the second hydraulic pressure sensor. electronic brake system. The method of claim 1,
The hydraulic supply device is
A motor operated by an electrical signal output in response to the displacement of the brake pedal, a power conversion unit for converting the rotational force of the motor into a translational motion, a cylinder block, and the power conversion unit are connected to the cylinder block and can be moved inside the cylinder block A hydraulic piston to be accommodated, a first pressure chamber provided on one side of the hydraulic piston 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,
a first hydraulic flow passage communicating with the first pressure chamber;
a second hydraulic oil passage branched from the first hydraulic oil passage;
a third hydraulic oil passage branched from the first hydraulic oil passage;
a fourth hydraulic flow passage communicating with the second pressure chamber;
a fifth hydraulic oil passage branching from the fourth hydraulic oil passage and joining the second hydraulic oil passage and the third hydraulic oil passage;
and a sixth hydraulic oil passage branched from the fourth hydraulic oil passage and joining the second hydraulic oil passage and the third hydraulic oil passage. 5. The method of claim 4,
a first control valve provided in the second hydraulic flow path to control the flow of oil;
a second control valve provided in the third hydraulic flow path to control the flow of oil;
a third control valve provided in the fifth hydraulic flow path to control the flow of oil; and
and a fourth control valve provided in the sixth hydraulic flow path to control the flow of oil. 6. The method of claim 5,
The first control valve, the second control valve, and the fourth control valve are provided as check valves that allow the flow of oil in a direction from the hydraulic pressure supply device to the wheel cylinder, but block the flow of oil in the opposite direction,
and the third control valve is provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the wheel cylinder. 5. The method of claim 4,
a seventh hydraulic oil passage communicating the second hydraulic oil passage and the third hydraulic oil passage;
and a fifth control valve provided in the seventh hydraulic flow path to control the flow of oil,
and the fifth control valve is provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the wheel cylinder. 8. The method of claim 7,
an eighth hydraulic oil passage communicating the second hydraulic oil passage and the seventh hydraulic oil passage;
and a sixth control valve provided in the eighth hydraulic flow path to control the flow of oil,
and the sixth control valve is provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the wheel cylinder. 5. The method of claim 4,
a first control valve provided in the second hydraulic flow path to control the flow of oil;
a second control valve provided in the third hydraulic flow path to control the flow of oil;
a third control valve provided in the fifth hydraulic flow path to control the flow of oil; and
It includes; a fourth control valve provided in the sixth hydraulic flow path to control the flow of oil;
The first to fourth control valves are provided as check valves that allow the flow of oil in a direction from the hydraulic pressure supply device to the wheel cylinder, but block the flow of oil in the opposite direction. 10. A method for controlling an electronic brake system according to any one of claims 1 to 9, comprising:
It is determined whether regenerative braking force is generated in the rear wheel of the vehicle,
When the regenerative braking force is generated, the hydraulic braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit connected to the rear wheel is controlled to be reduced in response to the regenerative braking force. 11. The method of claim 10,
A method of controlling an electronic brake system, wherein a sum of the hydraulic braking force and the regenerative braking force transmitted from the hydraulic pressure supply device to the first hydraulic circuit is at least equal to or smaller than the hydraulic braking force transmitted to the second hydraulic circuit.

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