KR20190023827A - Electric brake system - Google Patents

Abstract

An electric brake system is disclosed. According to an embodiment of the present invention, the electric brake system comprises: a reservoir in which oil is stored; a liquid pressure supply device generating liquid pressure with a hydraulic piston operated by an electric signal, and having a pressure chamber provided at one side of the hydraulic piston accommodated to move in a cylinder block to be connected to at least one wheel cylinder; a hydraulic flow path connecting the pressure chamber and the wheel cylinder; and a dump valve installed in a dump flow path connecting the pressure chamber and the reservoir to control a flow of oil. The dump valve is provided with a solenoid valve controlling a flow of oil in both directions between the liquid pressure supply device and the reservoir.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic brake system, and more particularly, to an electronic brake system that generates a braking force by an electrical signal.

The vehicle is essentially equipped with a brake system for braking. Recently, various types of systems have been proposed to obtain a more powerful and stable braking force.

Examples of the brake system include an anti-lock brake system (ABS) that prevents slippage of the wheel during braking, a brake traction control system (BTCS: Brake) that prevents slippage of the drive wheels And an electronic stability control system (ESC) that stably maintains the running state of the vehicle by controlling the brake hydraulic pressure by combining an anti-lock brake system and traction control.

Generally, an electronic brake system includes a hydraulic pressure supply device that receives an electric signal of a driver's braking will from a pedal displacement sensor that senses displacement of a brake pedal when the driver depresses the brake pedal, and supplies pressure to the wheel cylinder.

An electronic brake system equipped with such a hydraulic pressure supply device is disclosed in European Patent EP 2 520 473. According to the disclosed document, the hydraulic pressure supply device is configured to operate the motor in accordance with the power of the brake pedal to generate the braking pressure. At this time, the braking pressure is generated by converting the rotational force of the motor into a linear motion and pressing the piston.

On the other hand, the disc brake used in the electromagnetic brake system forms the braking force by the frictional force between the disc and the brake pad. This frictional force is generated by pressing the disc by the brake pad pushed by the influence of the hydraulic pressure generated by the driver's brake pedal operation. However, if the drag phenomenon that the brake pad and the disk are not completely separated after the braking is completed remains, the replacement time of the pad is shortened, and the output and fuel efficiency are reduced.

Conventionally, after the braking is completed, the knock back phenomenon between the brake pads and the disk and the restoring force of the caliper piston are used to separate the brake pads and the disk to remove the frictional force. However, such a method can not prevent the drag phenomenon from occurring frequently.

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

An embodiment of the present invention is to provide an electronic brake system having a retraction mode for forcibly retracting a piston of a caliper to reduce drag.

According to an aspect of the present invention, there is provided an oil pump comprising: a reservoir in which oil is stored; A hydraulic pressure supply device including a pressure chamber which is provided on one side of the hydraulic piston and is connected to at least one wheel cylinder, the hydraulic pressure piston being operated by an electric signal to generate a hydraulic pressure, the hydraulic pressure piston being accommodated movably in the cylinder block; A hydraulic oil connecting the pressure chamber and the wheel cylinder; And a dump valve installed in a dump passage connecting the pressure chamber and the reservoir and controlling the flow of oil, wherein the dump valve is a solenoid for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir, An electronic brake system provided with a valve may be provided.

Also, the dump valve may be a normally closed type valve that is normally closed and operates to open upon receipt of an open signal.

The hydraulic pressure supply device may include a first pressure chamber located forward of the pressure direction of the hydraulic piston and a second pressure chamber located behind the hydraulic piston, A second hydraulic oil passage branched from the first hydraulic oil passage, a third hydraulic oil passage branched from the first hydraulic oil passage, and a fourth hydraulic oil passage communicating with the second pressure chamber, wherein the first hydraulic oil passage communicates with the chamber, A fifth hydraulic oil path branched from the fourth hydraulic oil path and joined to the second hydraulic oil path, and a sixth hydraulic oil path branched from the fourth hydraulic fluid path and joined to the third hydraulic fluid path, A first hydraulic circuit including first and second branch flow paths branched from the two hydraulic oil paths so as to be respectively connected to the two wheel cylinders, and third and fourth branched hydraulic fluid circuits branched from the third hydraulic oil path to be connected to the two wheel cylinders, 4 It may further include a second hydraulic circuit including a flow path group.

The first control valve is provided in the second hydraulic oil passage and controls the flow of oil. The second control valve is provided in the third hydraulic oil passage and controls the flow of oil. Wherein at least one of the first to third control valves allows the flow of oil in the direction from the hydraulic pressure supply device to the wheel cylinder, May be provided as a check valve for shutting off.

The first and second control valves are provided as check valves that permit the flow of oil in the direction from the hydraulic pressure supply device toward the wheel cylinder and shut off the flow of oil in the opposite direction, 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.

A seventh hydraulic oil passage communicating with the second hydraulic oil passage and the third hydraulic oil passage may be further included, and a fifth control valve provided in the seventh hydraulic oil passage for controlling the flow of the oil.

In addition, the fifth control valve may be a normally closed type valve that is normally closed and operates to be opened when an open signal is received.

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 and controlling the flow of the oil may be further included.

In addition, the sixth control valve may be a normally closed type valve that is normally closed and operates to be opened when an open signal is received.

A first dump passage communicating with the first pressure chamber and connected to the reservoir; a second dump passage communicating with the second pressure chamber and connected to the reservoir; and a second dump passage provided in the first dump passage, A first dump valve provided in the second dump passage for controlling the flow of oil in the first dump passage and a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir, A second dump valve provided in the second dump passage and provided with a check valve for blocking the flow of oil in the opposite direction while permitting the flow of oil in a direction toward the second pressure chamber; A second solenoid valve for controlling the flow of oil in both directions between the reservoir and the second pressure chamber, A third dump valve is provided to de-valve may further include.

Also, the third dump valve may be a normally open type valve that is normally open and operates to close upon receipt of a closing signal.

According to another aspect of the present invention, there is provided an electric power steering apparatus comprising: a motor that is operated by an electrical signal output in response to displacement of a brake pedal; a power converting unit that converts a rotational force of the motor into translational motion; A first pressure chamber provided at one side of the piston and connected to at least one wheel cylinder, and a second pressure chamber provided at the other side of the piston and connected to one or more wheel cylinders, A hydraulic pressure supply device including a pressure chamber; 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 second hydraulic oil communicating with the first pressure chamber and providing a hydraulic pressure generated in the first pressure chamber to the wheel cylinder; A third hydraulic oil communicating with the first pressure chamber and providing a hydraulic pressure generated in the first pressure chamber to the wheel cylinder; A fifth hydraulic oil communicating with the second pressure chamber, joining the second hydraulic oil passage, and providing a hydraulic pressure generated in the second pressure chamber to the wheel cylinder; A sixth hydraulic oil communicating with the second pressure chamber, joining the third hydraulic oil passage, and providing a hydraulic pressure generated in the second pressure chamber to the wheel cylinder; A seventh hydraulic oil communicating the second hydraulic oil passage and the third hydraulic oil passage to communicate the hydraulic pressure of the wheel cylinder to the first pressure chamber; An eighth hydraulic oil communicating the seventh hydraulic oil path with the second hydraulic oil or the third hydraulic oil path to transfer the hydraulic pressure of the wheel cylinder to the first pressure chamber; A first dump valve provided in the first dump passage and provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir; A first control valve provided in the second hydraulic oil passage for controlling the flow of oil; A second control valve provided in the third hydraulic oil passage to control the flow of oil; A third control valve provided in the fifth hydraulic oil passage and controlling the flow of the oil; A fifth control valve provided in the seventh hydraulic oil passage or the eighth hydraulic oil passage for controlling the flow of oil; A first hydraulic oil path including first and second branch flow paths branched from the first hydraulic fluid path to be connected to two wheel cylinders respectively and first and second inlet valves respectively controlling the first and second branch flow paths, circuit; A second hydraulic circuit including third and fourth branch passages branched from the second hydraulic fluid passage to be connected to two wheel cylinders, respectively; And an electronic control unit (ECU) for controlling the operation of the motor and the opening and closing of the fifth control valve and the first through fourth inlet valves.

According to another aspect of the present invention, there is provided a brake pedal comprising: a brake pedal; A reservoir in which the oil is stored; A master cylinder having first and second hydraulic ports formed therein and connected to the reservoir and having one or more pistons to discharge oil according to the pressure of the brake pedal; A pedal displacement sensor for sensing a displacement of the brake pedal; A first backup oil channel connecting the first hydraulic port and the wheel cylinder; A second backup oil channel connecting the second hydraulic port and the wheel cylinder; A first cut valve provided in the first backup passage to control the flow of oil; A second cut valve provided in the second backup passage to control the flow of oil; A simulator provided in a flow path branched from the first backup passage and provided with a simulation chamber in which oil is received and a simulator valve provided in a flow path connecting the reservoir and providing a reaction force according to the power of the brake pedal; The hydraulic piston being provided on one side of the hydraulic piston accommodated movably in the cylinder block so as to generate a hydraulic pressure or a negative pressure by advancing and retracting the hydraulic piston using the rotational force of the motor operated by the electric signal outputted from the pedal displacement sensor A hydraulic pressure supply device including a pressure chamber connected to at least one wheel cylinder; A first hydraulic oil connected to the pressure chamber and joined to the first backup oil channel; A second hydraulic oil connected to the pressure chamber and joined to the second backup channel; And a hydraulic circuit connected to the first and second hydraulic oil passages and transmitting the hydraulic pressure discharged from the hydraulic pressure supply device to wheel cylinders provided to the wheels, A control unit; An electronic control unit for controlling the motor and the valves based on the hydraulic pressure information and the displacement information of the brake pedal; And a dump valve installed in a dump passage connecting the pressure chamber and the reservoir and controlling the flow of oil, wherein the dump valve is a solenoid for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir, Wherein the electronic control unit forms a negative pressure in the pressure chamber by retracting the hydraulic piston in a state in which the dump valve is closed and a negative pressure formed in the pressure chamber retracts the piston of the wheel cylinder, System can be provided.

Embodiments of the present invention include a retraction mode so that the brake pad can be completely detached from the disc, thereby preventing the dragging phenomenon originally. In addition, by preventing the drag shape, the output of the vehicle and the fuel consumption can be increased, and the replacement time of the pads can be delayed.

Further, by configuring the piston of the hydraulic pressure supply device in a double-acting type, it is possible to provide the hydraulic pressure more quickly and control the pressure increase more precisely.

Further, by providing a hydraulic pressure or a negative pressure by separating the low-pressure section and the high-pressure section, the braking force can be flexibly provided or released according to the braking situation.

Further, by using the high-pressure section, the braking force can be provided at a pressure greater than the maximum pressure in the low-pressure section.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a hydraulic circuit diagram showing a non-synchronized state of an electronic brake system according to an embodiment of the present invention; FIG.
2 is an enlarged view showing a hydraulic pressure providing unit according to an embodiment of the present invention.
3 is a hydraulic circuit diagram showing a situation in which the hydraulic piston advances and provides a braking pressure in the low pressure mode.
4 is a hydraulic circuit diagram showing a situation in which the hydraulic piston advances and provides a braking pressure in a high pressure mode.
5 is a hydraulic circuit diagram showing a situation in which the hydraulic piston provides a braking pressure while reversing.
6 is a hydraulic circuit diagram showing a situation in which the hydraulic pressure piston is released and the braking pressure is released in the high pressure mode.
7 is a hydraulic circuit diagram showing a situation in which the hydraulic pressure piston is released and the braking pressure is released in the low pressure mode.
8 is a hydraulic circuit diagram showing a situation in which the hydraulic pressure piston is advanced and the braking pressure is released.
9 and 10 show a state in which the ABS is actuated by the electromagnetic brake system according to the embodiment of the present invention. Fig. 9 shows a situation in which the hydraulic piston is selectively braked while advancing, Fig. 10 shows a state in which the hydraulic piston is retracted It is a hydraulic circuit diagram showing a situation where the engine is braked.
11 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system according to the embodiment of the present invention operates abnormally.
12 is a hydraulic circuit diagram showing a state in which the electronic brake system according to the embodiment of the present invention is operated in the dump mode.
13 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system according to the embodiment of the present invention is operated in a balanced mode.
14 is a hydraulic circuit diagram showing a state in which the electronic brake system according to the embodiment of the present invention is operated in the inspection mode.
15 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system according to the embodiment of the present invention is operated in the retraction mode.
16 is a diagram showing a state in which the drag phenomenon is removed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to fully convey the spirit of the present invention to a person having ordinary skill in the art to which the present invention belongs. The present invention is not limited to the embodiments shown herein but may be embodied in other forms. For the sake of clarity, the drawings are not drawn to scale, and the size of the elements may be slightly exaggerated to facilitate understanding.

Fig. 1 is a hydraulic circuit diagram showing the non-synchronized state of the electromagnetic brake system 1 according to the embodiment of the present invention.

1, the electronic brake system 1 typically includes a master cylinder 20 for generating hydraulic pressure, a reservoir 30 coupled to the top of the master cylinder 20 for storing oil, a brake pedal (not shown) An input rod 12 which pressurizes the master cylinder 20 in accordance with the pressing force of the brake pedal 10 and a wheel cylinder 40 which transmits hydraulic pressure to brake the wheels RR, RL, FR and FL, A pedal displacement sensor 11 for detecting the displacement of the brake pedal 10 and a simulation device 50 for providing a reaction force in response to the power of the brake pedal 10.

The master cylinder 20 may be configured to include at least one chamber to generate hydraulic pressure. In one example, the master cylinder 20 is configured to have two chambers, each chamber being provided with a first piston 21a and a second piston 22a, the first piston 21a being connected to the input rod 12 ). The master cylinder 20 may form first and second hydraulic ports 24a and 24b, respectively, through which fluid pressure is discharged from the two chambers.

On the other hand, the master cylinder 20 has two chambers to ensure safety in case of failure. For example, one of the two chambers may be connected to the right front wheel FR and the left rear wheel RL of the vehicle, and the other chamber may be connected to the left front wheel FL and the right rear wheel RR. Thus, by independently configuring the two chambers, it is possible to braking the vehicle even if one of the chambers fails.

Or one of the two chambers may be connected to the two front wheels FR and FL, and the other chamber may be connected to the two rear wheels RR and RL, as shown in the figure. In addition, one of the two chambers may be connected to the left front wheel FL and the left rear wheel RL, and one chamber may be connected to the right rear wheel RR and the right front wheel FR. That is, the positions of the wheels connected to the chambers of the master cylinder 20 can be variously configured.

A first spring 21b is provided between the first piston 21a and the second piston 22a of the master cylinder 20 and a second spring 21b is provided between the end of the master cylinder 20 and the second piston 22a. 2 spring 22b may be provided.

The first spring 21b and the second spring 22b are respectively provided in the two chambers and as the displacement of the brake pedal 10 changes, the first piston 21a and the second piston 22a are compressed, The elastic force is stored in the spring 21b and the second spring 22b. When the pushing force of the first piston 21a becomes smaller than the elastic force, the first and second pistons 21a and 22a are returned to the original state by using the elastic force stored in the first spring 21b and the second spring 22b .

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

The simulation apparatus 50 may be connected to a first backup passage 251 to be described later to provide a reaction force according to the pressing force of the brake pedal 10. The reaction force is provided as much as the driver's compensation is compensated for, so that the driver can finely adjust the braking force as intended.

1, the simulation apparatus 50 includes a simulation chamber 51 configured to store oil flowing out from the first hydraulic port 24a of the master cylinder 20 and a reaction force piston (not shown) provided in the simulation chamber 51 And a simulator valve 54 connected to the pedal simulator and the rear end of the simulation chamber 51. The simulator valve 54 is connected to the rear end of the simulation chamber 51,

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

On the other hand, the reaction force spring 53 shown in the drawings is only one embodiment capable of providing an elastic force to the reaction force piston 52, and may include various embodiments capable of storing elastic force by shape deformation. For example, it includes various members capable of storing an elastic force by being made of a material such as rubber or having a coil or a plate shape.

The simulator valve 54 may be provided in a flow path connecting the rear end of the simulation chamber 51 and the reservoir 30. [ The front end of the simulation chamber 51 is connected to the master cylinder 20 and the rear end of the simulation chamber 51 can be connected to the reservoir 30 through the simulator valve 54. Therefore, even when the reaction force piston 52 returns, oil in the reservoir 30 flows through the simulator valve 54, so that the entire interior of the simulation chamber 51 can be filled with the oil.

In the meantime, several reservoirs 30 are shown in the figure, and each reservoir 30 uses the same reference numerals. However, these reservoirs may be provided with the same parts or may be provided with different parts. For example, the reservoir 30 connected to the simulation apparatus 50 can store the oil separately from the reservoir 30 connected to the master cylinder 20, or to the reservoir 30 connected to the master cylinder 20 It can be a repository.

On the other hand, the simulator valve 54 may be constituted by a normally closed type solenoid valve that keeps the normally closed state. The simulator valve 54 can be opened when the driver applies pressure to the brake pedal 10 to deliver the oil in the simulation chamber 51 to the reservoir 30.

Further, a simulator check valve 55 may be provided between the pedal simulator and the reservoir 30 so as to be connected to the simulator valve 54 in parallel. The simulator check valve 55 allows the oil of the reservoir 30 to flow into the simulation chamber 51 while the oil of the simulation chamber 51 flows into the reservoir 30 through the flow path in which the check valve 55 is installed You can block things. A quick return of the pedal simulator pressure can be ensured since the oil can be supplied into the simulation chamber 51 through the simulator check valve 55 when the brake pedal 10 is depressed.

The simulating chamber 51 which pushes the reaction force spring 53 while compressing the reaction force piston 52 of the pedal simulator when the driver applies the pressing force to the brake pedal 10 will be described. Is delivered to the reservoir 30 through the simulator valve 54, in which the driver is provided with a feeling of a pedal. When the driver releases his / her foot to the brake pedal 10, the reaction force spring 52 pushes the reaction force piston 52 to return the reaction force piston 52 to its original state, and the oil of the reservoir 30 is returned to the simulator valve 54 may flow into the simulation chamber 51 through the flow path where the check valve 55 and the check valve 55 are installed, so that the oil can be filled in the simulation chamber 51.

Since the inside of the simulation chamber 51 is filled with oil at all times, friction of the reaction force piston 52 is minimized during operation of the simulation apparatus 50 to improve the durability of the simulation apparatus 50, Can be blocked.

An electronic brake system 1 according to an embodiment of the present invention includes a hydraulic pressure supply device 100 (hereinafter, referred to as " brake ") that receives mechanical signals of a driver's braking intent from a pedal displacement sensor 11 that senses displacement of a brake pedal 10, And first and second hydraulic circuits 201 and 202 for controlling the flow of hydraulic pressure transmitted to the wheel cylinders 40 provided in the two wheels RR, RL, FR and FL, respectively, A first cut valve 261 provided in a first backup passage 251 for connecting the first hydraulic pressure port 24a and the first hydraulic circuit 201 to control the flow of hydraulic pressure, A second cut valve 262 provided on a second backup passage 252 connecting the hydraulic port 24b and the second hydraulic circuit 202 to control the flow of the hydraulic pressure, And controls the supply device 100 and the valves 54,60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 241, And an electronic control unit (ECU) (not shown).

The hydraulic pressure supply device 100 includes a hydraulic pressure supply unit 110 for supplying oil pressure to the wheel cylinder 40, a motor 120 for generating a rotational force by an electrical signal of the pedal displacement sensor 11, And a power converting unit 130 that converts the rotational motion of the motor 120 into a rectilinear motion and transmits the rectilinear motion to the hydraulic pressure providing unit 110. Or the hydraulic pressure providing unit 110 may be operated not by the driving force supplied from the motor 120 but by the pressure provided by the high pressure accumulator.

Next, the hydraulic pressure providing unit 110 according to the embodiment of the present invention will be described with reference to FIG. 2 is an enlarged view showing a hydraulic pressure providing unit 110 according to an embodiment of the present invention.

The hydraulic pressure providing unit 110 includes a cylinder block 111 in which a pressure chamber to be stored with oil is formed, a hydraulic piston 114 housed in the cylinder block 111, a hydraulic piston 114 and a cylinder block 111 A driving shaft 115 connected to a rear end of the hydraulic piston 114 to transmit power output from the power converting unit 130 to the hydraulic piston 114, (133).

The pressure chamber includes a first pressure chamber 112 positioned forward (forward direction, leftward direction in the drawing) of the hydraulic piston 114 and a second pressure chamber 112 positioned rearward (backward direction, rightward in the drawing) of the hydraulic piston 114 And may include a second pressure chamber 113. That is, the first pressure chamber 112 is divided by the front end of the cylinder block 111 and the hydraulic piston 114, and the volume is changed according to the movement of the hydraulic piston 114, and the second pressure chamber 113 Is divided by the cylinder block 111 and the rear end of the hydraulic piston 114 and is provided so as to vary in volume as the hydraulic piston 114 moves.

The first pressure chamber 112 is connected to the first hydraulic oil path 211 through the first communication hole 111a formed on the rear side of the cylinder block 111 and formed on the front side of the cylinder block 111 And is connected to the fourth hydraulic oil passage 214 through the second communication hole 111b. The first hydraulic oil path 211 connects the first pressure tamper 112 and the first and second hydraulic circuits 201 and 202. The first hydraulic fluid path 211 is branched into a second hydraulic fluid path 212 communicating with the first hydraulic circuit 201 and a third hydraulic fluid path 212 communicating with the second hydraulic circuit 202. The fourth hydraulic fluid passage 214 connects the second pressure chamber 113 and the first and second hydraulic circuits 201, 202. The fourth hydraulic fluid path 214 branches to a fifth hydraulic fluid path 215 communicating with the first hydraulic circuit 201 and a sixth hydraulic fluid path 216 communicating with the second hydraulic circuit 202.

The sealing member 115 is provided between the hydraulic piston 114 and the cylinder block 111 and includes a piston sealing member 115a and a drive shaft 133 that seal between the first pressure chamber 112 and the second pressure chamber 113, And a driving shaft sealing member 115b provided between the cylinder block 111 and the second pressure chamber 113 and sealing the opening of the cylinder block 111. [ That is, the hydraulic pressure or the 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 is not leaked to the second pressure chamber 113, And fourth hydraulic oil passages 211 and 214, respectively. 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 and may not leak to the cylinder block 111. [

The first and second pressure chambers 112 and 113 are connected to the reservoir 30 by the dump passages 116 and 117 and are supplied with oil from the reservoir 30 or stored in the first or second pressure chamber 112, and 113 to the reservoir 30. For example, the dump channels 116 and 117 include a first dump channel 116 branched from the first pressure chamber 112 and connected to the reservoir 30, and a second dump channel 116 branched from the second pressure chamber 113 and connected to the reservoir 30 And a second dump passage 117 connected to the second dump passage 117.

The first pressure chamber 112 is connected to the first dump passage 116 through a fifth communication hole 111f formed on the front side and the second pressure chamber 113 is connected to the first dump passage 116 via a sixth And can be connected to the second dump passage 117 through the communication hole 111e.

A first communication hole 111a communicating with the first hydraulic oil path 211 is formed in front of the first pressure chamber 112. A fourth hydraulic fluid path 214 is formed in the rear of the first pressure chamber 112, A second communication hole 111b can be formed. The first pressure chamber 112 may further include a third communication hole 111c communicating with the first dump passage 116.

A third communication hole 111c communicating with the third hydraulic fluid passage 213 and a fourth communication hole 111d communicating with the second dump passage 117 may be formed in the second pressure chamber 113 have.

Referring again to FIG. 1, flow paths 211, 212, 213, 214, 215, 216, 217 connected to the first pressure chamber 112 and the second pressure chamber 113 and bands 231, 232, 233, 234, 235, 236, 241, 242 and 243 will be described.

The second hydraulic oil path 212 may communicate with the first hydraulic circuit 201 and the third hydraulic fluid path 213 may communicate with the second hydraulic circuit 202. [ Therefore, the hydraulic pressure can be transmitted to the first hydraulic circuit 201 and the second hydraulic circuit 202 by advancing the hydraulic piston 114.

The electromagnetic brake system 1 according to the embodiment of the present invention is provided with the first control valve 231 and the second control valve 231 which are respectively provided in the second and third hydraulic oil passages 212 and 213 to control the flow of oil, 232).

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 and 202, May be provided as a check valve for shutting off. That is, the first or second control valve 231 or 232 allows the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first or second hydraulic circuit 201 or 202, It is possible to prevent the hydraulic pressure of the circuits 201 and 202 from leaking to the first pressure chamber 112 through the second or third hydraulic oil paths 212 and 213. [

On the other hand, the fourth hydraulic oil path 213 may branch to the fifth hydraulic oil path 215 and the sixth hydraulic oil path 216 midway and may be communicated with both the first hydraulic circuit 201 and the second hydraulic circuit 202 . For example, the fifth hydraulic oil path 215 branched from the fourth hydraulic oil path 214 communicates with the first hydraulic circuit 201, and the sixth hydraulic oil path 216 branched from the fourth hydraulic oil path 214 And can communicate with the second hydraulic circuit (202). Therefore, the hydraulic pressure can be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 by the backward movement of the hydraulic piston 114. [

The electromagnetic brake system 1 according to the embodiment of the present invention is provided in the fifth hydraulic oil path 215 and provided in the third control valve 233 and the sixth hydraulic oil path 216 for controlling the flow of the oil, And a fourth control valve 234 for controlling the flow.

The third control valve 233 may be provided as a bidirectional control valve for controlling the flow of oil 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 the valve when receiving an open signal from the electronic control unit.

And 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 to the second pressure chamber 113 through the sixth hydraulic oil passage 216 and the fourth hydraulic oil passage 214 .

The electromagnetic brake system 1 according to the embodiment of the present invention is provided in the seventh hydraulic oil passage 217 connecting the second hydraulic oil passage 212 and the third hydraulic oil passage 213 to control the flow of oil And a sixth control valve 236 provided in the eighth hydraulic oil passage 218 for connecting the second hydraulic oil passage 212 and the seventh hydraulic oil passage 217 to control the flow of the oil can do. And the fifth control valve 235 and the sixth control valve 236 may be provided as a normally closed type (Normally Closed type) solenoid valve that is normally closed and operates to open the valve when receiving an open signal from the electronic control unit have.

The fifth control valve 235 and the sixth control valve 236 are operated to be opened when an abnormality occurs in the first control valve 231 or the second control valve 232 so that the pressure in the first pressure chamber 112 So that the hydraulic pressure can be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202.

And the fifth control valve 235 and the sixth control valve 236 can be operated to be opened when the wheel cylinder 40 is depressurized and sent to the first pressure chamber 112. The first control valve 231 and the second control valve 232 provided in the second hydraulic fluid passage 212 and the third hydraulic fluid passage 213 are provided as check valves allowing only one directional oil flow.

The electromagnetic brake system 1 according to the embodiment of the present invention includes a first dump valve 241 and a second dump valve 241 which are provided in the first and second dump flow paths 116 and 117 to control the flow of oil, 242).

The first dump valve 241 may be provided as a solenoid valve capable of controlling bidirectional flow of oil between the reservoir 30 and the first pressure chamber 112. The first dump valve 241 may be a normally closed type solenoid valve that is closed in a normal state and operates to open the valve when an open signal is received in the electronic control unit.

The second dump valve 242 may be a check valve that opens only the direction from the reservoir 30 to the second pressure chamber 113 and closes the opposite direction. That is, the second dump valve 242 allows the oil to flow from the reservoir 30 to the second pressure chamber 113 while blocking the flow of oil from the second pressure chamber 113 to the reservoir 30 It may be a check valve.

The second dump passage 117 may include a bypass passage and a third dump valve 243 is provided in the bypass passage for controlling the flow of oil between the second pressure chamber 113 and the reservoir 30 Can be installed.

The third dump valve 243 may be provided as a solenoid valve capable of controlling the bidirectional flow and is normally open when the valve is closed when the electronic control unit receives the closing signal, type solenoid valve.

The hydraulic pressure providing unit 110 of the electromagnetic brake system 1 according to the embodiment of the present invention can operate in a double acting manner. That is, the hydraulic pressure generated in the first pressure chamber 112 while the hydraulic piston 114 advances is transmitted to the first hydraulic circuit 201 through the first hydraulic oil path 211 and the second hydraulic fluid path 212, The wheel cylinders 40 provided on the front wheel FR and the left rear wheel LR can be actuated and transmitted to the second hydraulic circuit 202 through the first hydraulic oil path 211 and the third hydraulic fluid path 213 So that the wheel cylinders 40 provided on the right rear wheel RR and the left front wheel FL can be actuated.

Similarly, the hydraulic pressure generated in the second pressure chamber 113 while the hydraulic pressure piston 114 moves backward is transmitted to the first hydraulic circuit 201 through the fourth hydraulic fluid passage 214 and the fifth hydraulic fluid passage 215, The wheel cylinders 40 provided on the front wheels FR and the left rear wheels LR can be actuated and transmitted to the second hydraulic circuit 202 through the fourth hydraulic fluid path 214 and the sixth hydraulic fluid path 216, So that the wheel cylinders 40 provided on the right rear wheel RR and the left front wheel FL can be actuated.

The negative pressure generated in the first pressure chamber 112 while the hydraulic piston 114 moves back sucks the oil of the wheel cylinder 40 installed in the right front wheel FR and the left rear wheel LR, (RR) and the left front wheel (FL) through the first hydraulic oil path (201), the second hydraulic oil path (212) and the first hydraulic oil path (211) The oil in the cylinder 40 can be sucked and transferred to the first pressure chamber 112 through the second hydraulic circuit 202, the third hydraulic fluid path 213, and the first hydraulic fluid path 211.

Next, the motor 120 and the power converting unit 130 of the hydraulic pressure supplying apparatus 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 can generate a rotational force in a forward or reverse direction. The rotational angular velocity and rotational angle of the motor 120 can be precisely controlled. Since the motor 120 is a well-known technology, its detailed description will be omitted.

On the other hand, the electronic control unit includes valves (54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 241, 243). The operation in which a 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 causes the displacement of the hydraulic piston 114 through the power conversion unit 130 and the hydraulic pressure generated by the sliding movement of the hydraulic piston 114 in the pressure chamber is transmitted to the first and second hydraulic oil RL, FR, and FL through wheel cylinders 211 and 212, respectively.

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

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

A signal sensed by the pedal displacement sensor 11 is transmitted to an electronic control unit (ECU) (not shown) while a displacement occurs in the brake pedal 10, The worm shaft 131 is rotated in one direction. The rotational force of the warm shaft 131 is transmitted to the drive shaft 133 via the worm wheel 132 and the hydraulic pressure piston 114 connected to the drive shaft 133 moves forward to generate a hydraulic pressure in the first pressure chamber 112.

On the other hand, when the brake pedal 10 is depressed, the electronic control unit drives the motor 120 in the opposite direction so that the worm shaft 131 rotates in the opposite direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and generates a negative pressure in the first pressure chamber 112 while the hydraulic piston 114 connected to the drive shaft 133 returns (moves backward).

On the other hand, the hydraulic pressure and the negative pressure can be generated in the opposite direction. That is, when a displacement occurs in the brake pedal 10, a 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 Thereby rotating the worm shaft 131 in the opposite direction. The rotational force of the warm shaft 131 is transmitted to the drive shaft 133 via the worm wheel 132 and the hydraulic pressure piston 114 connected to the drive shaft 133 moves backward to generate a hydraulic pressure in the second pressure chamber 113.

On the other hand, when the pressing force is removed from the brake pedal 10, the electronic control unit drives the motor 120 in one direction so that the worm shaft 131 rotates in one direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and generates a negative pressure in the second pressure chamber 113 while the hydraulic piston 114 connected to the drive shaft 133 returns (advances).

The hydraulic pressure supply device 100 transfers the hydraulic pressure to the wheel cylinder 40 or sucks the hydraulic pressure to the reservoir 30 according to the rotational direction of the rotational force generated from the motor 120.

On the other hand, when the motor 120 rotates in one direction, a hydraulic pressure may be generated in the first pressure chamber 112 or a negative pressure may be generated in the second pressure chamber 113. The hydraulic pressure may be used for braking, Whether to release the braking operation can be determined by controlling the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 241 and 243. This will be described later in detail.

Although not shown in the drawing, the power conversion unit 130 may be formed of a ball screw nut assembly. For example, a screw formed integrally with the rotating shaft of the motor 120 or connected to rotate as the rotating shaft of the motor 120, and a ball nut screwed with the screw in a limited rotation state and linearly moving according to the rotation of the screw . The hydraulic piston 114 is connected to the ball nut of the power converting unit 130 to press the pressure chamber by linear motion of the ball nut. The structure of such a ball screw nut assembly is a device that converts rotational motion into linear motion and is a well-known technique that has been well known in the art, and thus a detailed description thereof will be omitted.

It should be understood that the power converting unit 130 according to the embodiment of the present invention can adopt any structure as long as it can convert rotational motion into linear motion in addition to the structure of the ball screw nut assembly.

The electromagnetic brake system 1 according to the embodiment of the present invention includes first and second backup oil passages 251 and 252 capable of supplying the oil discharged from the master cylinder 20 to the wheel cylinder 40 at the time of abnormal operation, , ≪ / RTI > 252).

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 have. The first backup hydraulic passage 251 connects the first hydraulic pressure port 24a to the first hydraulic pressure circuit 201 and the second backup hydraulic passage 252 connects the second hydraulic pressure port 24b and the second hydraulic circuit 202 can be connected.

The first and second cut valves 261 and 262 may be provided with a normally open type solenoid valve that is opened in a normal state and operates to close the valve when receiving a close signal from the electronic control unit have.

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

The hydraulic control unit 200 may include a first hydraulic circuit 201 and a second hydraulic circuit 202, each of which receives hydraulic pressure and controls two wheels, respectively. For example, the first hydraulic circuit 201 controls the right front wheel FR and the left rear wheel RL, and the second hydraulic circuit 202 can control the left front wheel FL and the right rear wheel RR . The wheel cylinders 40 are provided on the respective wheels FR, FL, RR, and RL to supply hydraulic pressure to perform braking.

The first hydraulic circuit 201 is connected to the first hydraulic fluid path 211 and the second hydraulic fluid path 212 to receive the hydraulic pressure from the hydraulic pressure supply device 100. The second hydraulic fluid path 212 is connected to the right front wheel FR ) And the left rear wheel (RL). Similarly, the second hydraulic circuit 202 is connected to the first hydraulic oil path 211 and the third hydraulic oil path 213 to receive the hydraulic pressure from the hydraulic pressure supply device 100, and the third hydraulic oil path 213 is connected to the left front wheel (FL) and the right rear wheel (RR).

The hydraulic circuits 201 and 202 may have a plurality of inlet valves 221 (221a, 221b, 221c and 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 oil path 211 and controlling the hydraulic pressures transmitted to the two wheel cylinders 40, respectively . The second hydraulic circuit 202 may be provided with two inlet valves 221c and 221d which are connected to the second hydraulic fluid path 212 and control hydraulic pressures transmitted to the wheel cylinders 40, respectively.

The inlet valve 221 is disposed on the upstream side of the wheel cylinder 40 and is opened in a steady state. When the solenoid valve 221 receives a close signal from the electronic control unit, a normally open type solenoid valve .

The hydraulic circuits 201 and 202 include check valves 223a, 223b, 223c and 223d provided in a bypass flow path connecting the inlet valves 221a, 221b, 221c and 221d to the front and the rear of the inlet valves 221a, 221b, 221c and 221d . The check valves 223a, 223b, 223c and 223d allow only the flow of oil in the direction from the wheel cylinder 40 toward the hydraulic pressure providing unit 110 and the oil from the hydraulic pressure providing unit 110 to the wheel cylinder 40 May be provided to limit the flow. The check valves 223a, 223b, 223c and 223d can quickly release the braking pressure of the wheel cylinders 40. When the inlet valves 221a, 221b, 221c and 221d are not operated normally, So that the hydraulic pressure of the hydraulic pump 40 can be introduced into the hydraulic pressure providing unit 110.

The hydraulic circuits 201 and 202 may further include a plurality of outlet valves 222 (222a, 222b, 222c, and 222d) connected to the reservoir 30 to improve performance during braking. The outlet valve 222 is connected to the wheel cylinder 40 to control the hydraulic pressure from the wheels RR, RL, FR and FL, respectively. That is, the outlet valve 222 senses the braking pressure of each of the wheels RR, RL, FR and FL and is selectively opened to control the pressure when the pressure reduction braking is required.

And the outlet valve 222 may be provided with a normally closed type solenoid valve that is normally closed and operates to open the valve when receiving an open signal from the electronic control unit.

Further, the hydraulic control unit 200 can be connected to the backup channels 251 and 252. The first hydraulic circuit 201 is connected to the first backup hydraulic line 251 to receive the hydraulic pressure from the master cylinder 20 and the second hydraulic circuit 202 is connected to the second backup hydraulic line 252 The hydraulic pressure can be supplied from the master cylinder 20.

At this time, the first backup oil passage 251 can join the first hydraulic circuit 201 upstream of the first and second inlet valves 221a and 221b. Similarly, the second backup oil passage 252 can 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 by the hydraulic pressure supply device 100 is supplied to the wheel cylinder 40 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 by the master cylinder 20 is supplied to the wheel cylinder 40 through the first and second backup oil channels 251 and 252 . At this time, since the plurality of inlet valves 221a, 221b, 221c, and 221d are in the open state, it is not necessary to switch the operation state.

Reference numeral " PS1 " is a hydraulic pressure sensor for sensing the hydraulic pressure of the hydraulic circuits 201 and 202, and PS2 is a backup hydraulic pressure sensor for measuring the oil pressure of the master cylinder 20. [ MPS "is a motor control sensor for controlling the rotation angle of the motor 120 or the current of the motor.

Hereinafter, the operation of the electromagnetic brake system 1 according to the embodiment of the present invention will be described in detail.

The hydraulic pressure supply device 100 can be used by separating the low pressure mode and the 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 generate a high hydraulic pressure without increasing the output of the motor 120 by using the high pressure mode. Therefore, it is possible to secure stable braking power while lowering the price and weight of the brake system.

More specifically, the hydraulic piston 114 generates hydraulic pressure in the first pressure chamber 112 while advancing. The amount of the oil delivered from the first pressure chamber 112 to the wheel cylinder 40 increases as the hydraulic piston 114 advances in the initial state, that is, as the stroke of the hydraulic piston 114 increases, Rise. 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. [

At this time, the maximum pressure in the low pressure mode is smaller than the maximum pressure in the high pressure mode. However, the pressure increase rate per stroke of the hydraulic piston 114 is small in the high pressure mode as compared with the low pressure mode. All of the oil pushed out of the first pressure chamber 112 is not introduced into the wheel cylinder 40 but a part of the oil flows into the second pressure chamber 113. This will be described in detail in FIG.

Therefore, a low-pressure mode in which the rate of increase in pressure per stroke is large is used in the early braking period where the braking response is important, and a high-pressure mode in which the maximum braking force is important in the late braking period.

Fig. 3 is a hydraulic circuit diagram showing a situation in which the hydraulic piston 114 advances to provide a braking pressure in a low pressure mode, and Fig. 4 a hydraulic circuit diagram showing a situation in which the hydraulic piston 114 advances to provide a braking pressure in a high pressure mode.

When the braking by the driver is started, the amount of brake demand of the driver can be sensed through the pedal displacement sensor 11 through information such as the pressure of the brake pedal 10 depressed by the driver. An electronic control unit (not shown) receives the electrical signal output from the pedal displacement sensor 11 and drives the motor 120.

The electronic control unit receives the magnitude of the regenerative braking amount through the backup hydraulic pressure sensor PS2 provided at the outlet side of the master cylinder 20 and the hydraulic pressure sensor PS1 provided at the second hydraulic circuit 202 , The magnitude of the friction damping amount can be calculated according to the difference between the demand braking amount and the regenerating braking amount of the driver, and the magnitude of the pressure increase or the pressure decrease of the wheel cylinder 40 can be grasped.

3, when the driver depresses the brake pedal 10 at the beginning of braking, the motor 120 is operated to rotate in one direction, and the rotational force of the motor 120 is transmitted to the hydraulic pressure supply unit 130 by the power transmission unit 130. [ And the hydraulic pressure piston 114 of the hydraulic pressure providing unit 110 advances to generate the hydraulic pressure in the first pressure chamber 112. [ The hydraulic pressure discharged from the hydraulic pressure providing unit 110 is transmitted to the wheel cylinders 40 provided on the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate the braking force. At this time, the first dump valve 241 may be kept closed to allow the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first and second hydraulic circuits 201 and 202.

Specifically, the hydraulic pressure provided in the first pressure chamber 112 is transmitted to the two wheels FR and RL through the first hydraulic oil passage 211 and the second hydraulic oil passage 212 connected to the first communication hole 111a, To the wheel cylinder 40 provided in the wheel cylinder 40. At this time, the first and second inlet valves 221a and 221b installed in the two flow paths branched from the second hydraulic oil path 212 are provided in an open state. In addition, the first and second outlet valves 222a and 222b provided in the flow paths branched respectively from the two hydraulic fluid paths branched from the second hydraulic fluid path 212 are kept closed to leak hydraulic pressure to the reservoir 30 Stop.

The hydraulic pressure provided in the first pressure chamber 112 is provided to the two wheels RR and FL through the first hydraulic oil passage 211 and the third hydraulic oil passage 213 connected to the first communication hole 111a To the wheel cylinder 40, as shown in Fig. At this time, the third and fourth inlet valves 221c and 221d, which are respectively installed in the two flow paths branched from the third hydraulic fluid path 213, are opened. The third and fourth outlet valves 222c and 222d provided in the flow paths branched from the two hydraulic flow paths branched from the third hydraulic fluid path 213 are kept closed to leak hydraulic pressure to the reservoir 30 Stop.

The fifth control valve 235 and the sixth control valve 236 may be opened to open the seventh hydraulic oil path 217 and the eighth hydraulic oil path 218. The seventh hydraulic oil path 217 and the eighth hydraulic oil path 218 are opened and the second hydraulic fluid path 212 and the third hydraulic fluid path 213 communicate with each other. However, at least one of the fifth control valve 235 and the sixth control valve 236 may be kept closed as necessary.

The third control valve 233 may be kept closed to shut off the fifth hydraulic oil path 215. The hydraulic pressure generated in the first pressure chamber 112 is prevented from being transmitted to the second pressure chamber 113 through the fifth hydraulic oil passage 215 connected to the second hydraulic oil passage 212, have. 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 corresponding to the pressing force of the brake pedal 10, at least one of the first to fourth outlet valves 222 is opened, As shown in FIG.

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

The pressure generated in response to the pressing force of the brake pedal 10 in accordance with the pressure of the master cylinder 20 is transmitted to the simulation apparatus 50 connected to the master cylinder 20. [ At this time, the normally closed simulator valve 54 disposed at the rear end of the simulation chamber 51 is opened, and the oil filled in the simulation chamber 51 through the simulator valve 54 is transferred to the reservoir 30. Further, a pressure corresponding to the load of the reaction force spring 53, in which the reaction force piston 52 is moved and which supports the reaction force piston 52, is formed in the simulation chamber 51 to provide an appropriate pedal feeling to the driver.

The hydraulic pressure sensor PS1 with the hydraulic oil installed in the second hydraulic oil passage 212 is connected to the left front wheel FL or the wheel cylinder 40 (hereinafter simply referred to as the wheel cylinder 40) provided on the right rear wheel RR, The flow rate can be detected. Therefore, the hydraulic pressure supplied to the wheel cylinder 40 can be controlled by controlling the hydraulic pressure supply device 100 according to the output of the pressure sensor PS1 with the hydraulic oil. Specifically, the flow rate and discharge speed of the wheel cylinder 40 can be controlled by controlling the advance distance and the advance speed of the hydraulic piston 114.

On the other hand, before the hydraulic piston 114 advances to the maximum, it is possible to switch from the low-pressure mode shown in Fig. 3 to the high-pressure mode shown in Fig.

Referring to FIG. 4, in the high pressure mode, the third control valve 233 may be opened to open the fifth hydraulic oil path 215. The hydraulic pressure generated in the first pressure chamber 112 is transmitted to the second pressure chamber 113 through the fifth hydraulic oil passage 215 connected to the second hydraulic oil passage 212 to push out the hydraulic piston 114 Can be used. At this time, the first dump valve 241 may be kept closed to allow the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first and second hydraulic circuits 201 and 202.

In the high pressure mode, a part of the oil pushed out of the first pressure chamber 112 flows into the second pressure chamber 113, so that the rate of pressure increase per stroke decreases. However, since a part of the hydraulic pressure generated in the first pressure chamber 112 is used to push out the hydraulic piston 114, the maximum pressure is increased. The reason why the maximum pressure is increased at this time is that 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.

5 is a hydraulic circuit diagram showing a situation in which the hydraulic piston 114 provides a braking pressure while reversing.

5, when the driver depresses the brake pedal 10 at the beginning of braking, the motor 120 is operated to rotate in the opposite direction, and the rotational force of the motor 120 is transmitted to the hydraulic pressure supply unit 130 by the power transmission unit 130. [ And the hydraulic pressure piston 114 of the hydraulic pressure providing unit 110 moves backward to generate the hydraulic pressure in the second pressure chamber 113. [ The hydraulic pressure discharged from the hydraulic pressure providing unit 110 is transmitted to the wheel cylinders 40 provided on the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate the braking force. At this time, the first dump valve 241 may be opened so that the oil of the reservoir 30 is transferred to the first pressure chamber 112.

Specifically, the hydraulic pressure provided in the second pressure chamber 113 is transmitted to the two wheels FR and RL through the fourth hydraulic oil passage 214 and the fifth hydraulic oil passage 215, which are connected to the second communication hole 111b. To the wheel cylinder 40 provided in the wheel cylinder 40. At this time, the first and second inlet valves 221a and 221b, which are respectively installed in the two flow paths branched by the fifth hydraulic oil path 215, are opened. In addition, the first and second outlet valves 222a and 222b provided in the flow paths branched respectively from the two hydraulic fluid paths branched from the second hydraulic fluid path 212 are kept closed to leak hydraulic pressure to the reservoir 30 Stop.

The hydraulic pressure provided in the second pressure chamber 113 is provided to the two wheels RR and FL through the fourth hydraulic oil passage 214 and the sixth hydraulic oil passage 216 connected to the second communication hole 111b To the wheel cylinder 40, as shown in Fig. At this time, the third and fourth inlet valves 221c and 221d, which are respectively installed in the two flow paths branched by the sixth hydraulic oil path 216, are opened. The third and fourth outlet valves 222c and 222d provided in the flow paths branched respectively from the two hydraulic fluid paths branched from the sixth hydraulic fluid path 216 are kept closed to leak hydraulic pressure to the reservoir 30 Stop.

Then, the third control valve 233 is switched to the open state to open the fifth hydraulic oil path 215. On the other hand, since the fourth control valve 234 is provided as a check valve that allows hydraulic pressure to be transmitted from the second pressure chamber 113 to the wheel cylinder 40, the sixth hydraulic oil passage 216 is opened.

The sixth control valve 236 may be kept closed to shut off the eighth hydraulic oil path 218. The hydraulic pressure generated in the second pressure chamber 113 is prevented from being transmitted to the first pressure chamber 112 through the eighth hydraulic oil path 218 connected to the fifth hydraulic oil path 215, have. Therefore, a quick braking response can be expected at the beginning of braking.

Next, the case of releasing the braking force in the braking state in the normal operation of the electromagnetic brake system 1 according to the embodiment of the present invention will be described.

Fig. 6 is a hydraulic circuit diagram showing a situation in which the hydraulic pressure piston 114 releases the braking pressure in the high pressure mode while the hydraulic pressure piston 114 is reversed, and Fig. 7 is a hydraulic pressure circuit diagram showing a situation in which the hydraulic pressure piston 114 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 a rotational force in the opposite direction to deliver the rotational force to the power converting unit 130, The shaft 131, the worm wheel 132 and the drive shaft 133 are rotated in the opposite direction to rotate the hydraulic piston 114 back to the original position to release the pressure in the first pressure chamber 112 . 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 transfers the hydraulic pressure to the first pressure chamber 112. At this time, the first dump valve 241 maintains the closed state to prevent the negative pressure of the first pressure chamber 112 from being transmitted to the reservoir 30.

The negative pressure generated in the first pressure chamber 112 is transmitted to the two wheels FR and RL through the first hydraulic oil passage 211 and the second hydraulic oil passage 212 connected to the first communication hole 111a, The pressure of the wheel cylinder 40 provided in the wheel cylinder 40 is released. At this time, the first and second inlet valves 221a and 221b installed in the two flow paths branched from the second hydraulic oil path 212 are provided in an open state. The first and second outlet valves 222a and 222b provided in the oil flow paths branched from the two oil flow paths branched from the second hydraulic oil path 212 are kept closed to allow the oil of the reservoir 30 to flow Stop.

The negative pressure generated in the first pressure chamber 112 is provided to the two wheels FL and RR through the first hydraulic oil passage 211 and the third hydraulic oil passage 213 connected to the first communication hole 111a The pressure of the wheel cylinder 40 is released. At this time, the third and fourth inlet valves 221c and 221d, which are respectively installed in the two flow paths branched from the third hydraulic fluid path 213, are opened. The third and fourth outlet valves 222c and 222d provided in the oil flow paths branched from the two oil flow paths branched from the third hydraulic oil path 213 are kept closed to allow the oil of the reservoir 30 to flow Stop.

Then, the third control valve 233 is opened to open the fifth hydraulic oil path 215, the fifth control valve 235 is opened to open the seventh hydraulic oil path 217, 6 control valve 236 can be opened to open the eighth hydraulic oil path 218. [ The fifth hydraulic oil passage 215, the seventh hydraulic oil passage 217 and the eighth hydraulic oil passage 218 communicate with each other so that the first pressure chamber 112 and the second pressure chamber 113 communicate with each other.

In order to form a negative pressure in the first pressure chamber 112, the hydraulic piston 114 must move backward. When the oil in the second pressure chamber 113 is filled with oil, the hydraulic piston 114 is moved backward and a resistance is generated. At this time, the third control valve 233, the fifth control valve 235 and the sixth control valve 236 are opened so that the fourth hydraulic fluid passage 214 and the fifth hydraulic fluid passage 215 are communicated with the second hydraulic fluid passage 212 and the first hydraulic oil path 211, the oil in the second pressure chamber 113 is moved to the first pressure chamber 112.

And the third dump valve 243 can be switched to the closed state. The third dump valve 243 is closed so that the oil in the second pressure chamber 113 can be discharged only to the fourth hydraulic oil passage 214. [ However, in some cases, the third dump valve 243 is kept open so that the oil in the second pressure chamber 113 may flow into the reservoir 30.

When the negative pressure transmitted to the first and second hydraulic circuits 201 and 202 is measured to be higher than the target pressure release value corresponding to the release amount of the brake pedal 10, It is possible to control to open one or more of them so as to follow the target pressure value.

The first and second hydraulic oil passages 251 and 252 connected to the first and second hydraulic ports 24a and 24b of the master cylinder 20 generate hydraulic pressure in the hydraulic pressure supply device 100, 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 shown in Fig. 6, the oil in the second pressure chamber 113, together with the oil in the wheel cylinder 40, is discharged by the negative pressure in the first pressure chamber 112 generated while the hydraulic piston 114 is moved backward The pressure reduction rate of the wheel cylinder 40 is small because it moves to the pressure chamber 112. Therefore, it may be difficult to release the pressure quickly in the high pressure mode.

For this reason, the high-pressure mode can be used only in a high-pressure state, and can be switched to the low-pressure mode shown in FIG. 7 when the pressure is lowered to a certain level or lower.

7, in the low-pressure mode, the third control valve 233 is maintained in a closed state or switched so that the third dump valve 243 is switched or held in an open state instead of closing the fifth hydraulic fluid path 215 The second pressure chamber 113 can be connected to the reservoir 30. At this time, the first dump valve 241 maintains the closed state to prevent the negative pressure of the first pressure chamber 112 from being transmitted to the reservoir 30.

In the low pressure mode, since the negative pressure generated in the first pressure chamber 112 is used only to suck the oil stored in the wheel cylinder 40, the pressure decrease rate per stroke of the hydraulic piston 114 increases as compared with the high pressure mode.

7, the braking force of the wheel cylinder 40 can be released even when the hydraulic piston 114 moves in the reverse direction, that is, advances.

8 is a hydraulic circuit diagram showing a situation in which the hydraulic pressure piston is advanced and the braking pressure is released.

Referring to FIG. 8, when the pedal force applied to the brake pedal 10 is released, the motor 120 generates a rotational force in the opposite direction to deliver the rotational force to the power converting unit 130, The shaft 131, the worm wheel 132 and the drive shaft 133 are rotated in opposite directions to advance the hydraulic piston 114 to the original position, thereby releasing the pressure in the second pressure chamber 113 or reducing the negative pressure . 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 transfers the hydraulic pressure to the second pressure chamber 113. At this time, the first dump valve 241 may be opened so that the oil in the first pressure chamber 112 is transferred to the reservoir 30.

Specifically, the negative pressure generated in the second pressure chamber 113 is transmitted through the fourth hydraulic oil passage 214, the fifth hydraulic oil passage 215, and the second hydraulic oil passage 212, which are connected to the second communication hole 111b The pressure of the wheel cylinder 40 provided on the two wheels FR and RL is released. At this time, the first and second inlet valves 221a and 221b installed in the two flow paths branched from the second hydraulic oil path 212 are provided in an open state. The first and second outlet valves 222a and 222b provided in the oil flow paths branched from the two oil flow paths branched from the second hydraulic oil path 212 are kept closed to allow the oil of the reservoir 30 to flow Stop.

The negative pressure generated in the second pressure chamber 113 is transmitted through the fourth hydraulic oil passage 214 connected to the second communication hole 111b, the fifth hydraulic oil passage 215, the seventh hydraulic oil passage 217, The pressure of the wheel cylinder 40 provided on the two wheels FL and RR is released through the passage 213. [ At this time, the third and fourth inlet valves 221c and 221d, which are respectively installed in the two flow paths branched from the third hydraulic oil path 216, are opened. The third and fourth outlet valves 222c and 222d provided in the oil flow paths branched from the two oil flow paths branched from the third hydraulic oil path 213 are kept closed to allow the oil of the reservoir 30 to flow Stop.

The third control valve 233 is switched to the open state to open the fifth hydraulic oil path 215 and the fifth control valve 235 to the open state to open the seventh hydraulic oil path 217 .

When the negative pressure transmitted to the first and second hydraulic circuits 201 and 202 is measured to be higher than the target pressure release value corresponding to the release amount of the brake pedal 10, It is possible to control to open one or more of them so as to follow the target pressure value.

The first and second hydraulic oil passages 251 and 252 connected to the first and second hydraulic ports 24a and 24b of the master cylinder 20 generate hydraulic pressure in the hydraulic pressure supply device 100, 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.

The pressure sensor PS1 with the hydraulic oil installed in the second hydraulic oil passage 212 can detect the flow rate discharged from the left front wheel FL or the wheel cylinder 40 provided at the right rear wheel RR. Therefore, the flow rate discharged from the wheel cylinder 40 can be controlled by controlling the hydraulic pressure supply device 100 in accordance with the output of the pressure sensor PS1 with the hydraulic oil. Specifically, the flow rate and discharge speed of the wheel cylinder 40 can be controlled by controlling the advance distance and the advance speed of the hydraulic piston 114.

9 and 10 show a state in which the electromagnetic brake system 1 according to the embodiment of the present invention is actuated by the ABS. Fig. 9 shows a situation in which the hydraulic piston 114 is selectively braked while advancing, Is a hydraulic circuit diagram showing a situation in which the hydraulic piston 114 is selectively braked while being reversed.

When the motor 120 is operated according to the urging force of the brake pedal 10, the rotational force of the motor 120 is transmitted to the hydraulic pressure providing unit 110 through the power transmitting portion 130, thereby generating hydraulic pressure. At this time, the first and second cut valves 261 and 262 are closed so that the hydraulic pressure discharged from the master cylinder 20 is not transmitted to the wheel cylinder 40.

9, a hydraulic pressure is generated in the first pressure chamber 112 while the hydraulic piston 114 advances, and the fourth inlet valve 221d is provided in an open state, so that the first hydraulic oil passage 211 and the third hydraulic oil The wheel cylinder 40 in which the hydraulic pressure transmitted through the bypass line 213 is located on the left front wheel FL is operated to generate the braking force.

At this time, the first to third inlet valves 221a, 221b and 221c are switched to the closed state and the first to fourth outlet valves 222a, 222b, 222c and 222d are kept closed. At this time, the first dump valve 241 may be kept closed so that the hydraulic pressure of the first pressure chamber 112 may be transmitted to the first and second hydraulic circuits 201 and 202. The third dump valve 243 is provided in an open state to fill the reservoir 30 with oil into the second pressure chamber 113.

10, the hydraulic pressure piston 114 is moved backward to generate a hydraulic pressure in the second pressure chamber 113, and the first inlet valve 221a is provided in an open state, so that the fourth hydraulic oil passage 214 and the second hydraulic oil The wheel cylinder 40, which is located on the right front wheel FR, is operated to generate a braking force.

At this time, the second to fourth inlet valves 221b, 221c and 221d are switched to the closed state, and the first to fourth outlet valves 222a, 222b, 222c and 222d are kept closed. The first dump valve 241 may be opened to transfer the oil of the reservoir 30 to the first pressure chamber 112.

That is, the electromagnetic brake system 1 according to the embodiment of the present invention includes the motor 120 and the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, The hydraulic pressure can be selectively transmitted to or discharged from the wheel cylinders 40 of the wheels RL, RR, FL and FR according to the required pressure by independently controlling the operations of the wheel cylinders 236, 236, 241, .

Next, the case where the above-described electronic brake system 1 does not operate normally will be described. 11 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system 1 according to the embodiment of the present invention operates abnormally.

Referring to FIG. 11, when the electromagnetic brake system 1 is not operated normally, the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 241, 243 are provided in an initial state of braking which is in a non-operating state.

When the driver presses the brake pedal 10, the input rod 12 connected to the brake pedal 10 advances and at the same time the first piston 21a contacting the input rod 12 advances and the first piston The second piston 22a is also advanced by the pressure or movement of the second piston 21a. At this time, since there is no gap between the input rod 12 and the first piston 21a, braking can be performed quickly.

The hydraulic pressure discharged from the master cylinder 20 is transmitted to the wheel cylinder 40 via the first and second backup oil channels 251 and 252 connected to the backup brake for realizing the braking force.

At this time, the first and second cut valves 261 and 262 provided on the first and second backup oil passages 251 and 252 and the oil passages for opening and closing the flow paths of the first and second hydraulic circuits 201 and 202 The inlet valve 221 is normally constituted by an open solenoid valve and the hydraulic pressure is immediately transmitted to the four wheel cylinders 40 as the simulator valve 54 and the outlet valve 222 are constituted by normally closed solenoid valves. Therefore, stable braking can be performed and the braking stability can be improved.

12 is a hydraulic circuit diagram showing a state in which the electronic brake system 1 according to the embodiment of the present invention is operated in the dump mode.

The electromagnetic brake system 1 according to the embodiment of the present invention can discharge only the braking pressure provided to the wheel cylinder 40 through the first to fourth outlet valves 222a, 222b, 222c, and 222d.

Referring to FIG. 12, the first to fourth inlet valves 221a, 221b, 221c and 221d are switched to the closed state, the first to third outlet valves 222a, 222b and 222c are kept closed, When the fourth outlet valve 222d is switched to the opened state, the hydraulic pressure discharged from the wheel cylinder 40 provided in the left front wheel FL is discharged to the reservoir 30 through the fourth outlet valve 222d.

The reason why the hydraulic pressure of the wheel cylinder 40 is discharged through the outlet valve 222 is that the pressure in the reservoir 30 is smaller than the pressure in the wheel cylinder 40. [ Usually, the pressure of the reservoir 30 is set at atmospheric pressure. Since the pressure in the wheel cylinder 40 is substantially higher than the atmospheric pressure, the hydraulic pressure in the wheel cylinder 40 is quickly discharged to the reservoir 30 when the outlet valve 222 is opened.

Although not shown in the drawing, the fourth outlet valve 222d is opened to discharge the hydraulic pressure of the wheel cylinder 40, and the first to third inlet valves 221a, 221b, and 221c are opened And supply the liquid pressure to the remaining three wheels FR, RL, RR.

The flow rate discharged from the wheel cylinder 40 increases as the difference between the pressure in the wheel cylinder 40 and the pressure in the first pressure chamber 112 increases. For example, the greater the volume of the first pressure chamber 112 while the hydraulic piston 114 is moving backward, the larger the flow rate can be discharged from the wheel cylinder 40.

By independently controlling the valves 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236 and 241243 of the hydraulic control unit 200, The hydraulic pressure can be transmitted to and discharged from the wheel cylinders 40 of the respective wheels RL, RR, FL and FR, and precise pressure control becomes possible.

When the hydraulic piston 114 of the hydraulic pressure providing unit 110 moves forward, the first dump valve 241 is opened so that the oil of the reservoir 30 can be transferred to the first pressure chamber 112 have.

13 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system 1 according to the embodiment of the present invention is operated in a balanced mode.

The balance mode can be started when the pressures of the first pressure chamber 112 and the second pressure chamber 113 are not balanced. For example, the electronic control unit can detect the unbalanced state of the pressure by finding the hydraulic pressure of the first hydraulic circuit 201 and the hydraulic pressure of the second hydraulic circuit 202 from the pressure sensor PS1 with the hydraulic oil.

In the balanced mode, the first and second pressure chambers 112 and 113 of the pressure providing unit 110 may be connected to perform a balancing process so that the pressure is balanced. Generally, the pressures of the first pressure chamber 112 and the second pressure chamber 113 are in equilibrium. For example, in a braking situation in which the hydraulic piston 114 advances to apply the braking force, only the hydraulic pressure of the first pressure chamber 112 of the two pressure chambers is transmitted to the wheel cylinder 40. In this case, however, since the oil of the reservoir 30 is transferred to the second pressure chamber 113 through the second dump passage 117, the equilibrium of the two pressure chambers is not broken. On the contrary, in the braking state in which the hydraulic piston 114 is moved backward and the braking force is applied, only the fluid pressure of the second pressure chamber 113 of the two pressure chambers is transmitted to the wheel cylinder 40. In this case, however, since the oil of the reservoir 30 is transferred to the first pressure chamber 112 through the second dump passage 116, the equilibrium of the two pressure chambers is not broken.

However, in the case where leakage occurs due to repetitive operation of the hydraulic pressure supply device 100 or abrupt start of the ABS operation, the pressure balance between the first pressure chamber 112 and the second pressure chamber 113 may be broken. That is, the hydraulic piston 114 may not be in the calculated position and malfunction may occur.

Hereinafter, the case where the pressure of the first pressure chamber 112 is greater than the pressure of the second pressure chamber 113 will be described as an example. When the motor 120 is operated, the hydraulic piston 114 advances. In this process, the pressure of the first pressure chamber 112 and the pressure of the second pressure chamber 113 are balanced. If the pressure in the second pressure chamber 113 is greater than the pressure in the first pressure chamber 112, the liquid pressure in the second pressure chamber 113 is transferred to the first pressure chamber 112 so that the pressure is balanced .

13, in the balanced mode, the third control valve 233 and the sixth control valve 236 are opened to open the fifth hydraulic oil path 215 and the eighth hydraulic oil path 218 . That is, the second hydraulic oil passage 212, the eighth hydraulic oil passage 218, the seventh hydraulic oil passage 217, and the fifth hydraulic oil passage 215 are connected to each other so that the first pressure chamber 112 and the second pressure chamber 113 ). Accordingly, the pressure in the first pressure chamber 112 and the pressure in the second pressure chamber 113 are balanced. At this time, the motor 120 may be operated to move the hydraulic piston 114 forward or backward so that the balancing process proceeds quickly. The first dump valve 241 is kept closed to prevent the hydraulic pressure of the first pressure chamber 112 from being transmitted to the reservoir 30.

14 is a hydraulic circuit diagram showing a state in which the electronic brake system 1 according to the embodiment of the present invention is operated in the inspection mode.

As shown in FIG. 14, when the electronic brake system 1 is operating abnormally, the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236 The first and second cut valves 261 and 262 provided on the first and second backup flow paths 251 and 252 and the first and second cut valves 261 and 262 provided on the respective wheels RR and RL The inlet valve 221 provided on the upstream side of the wheel cylinder 40 provided in the front wheels FR, FL is opened and the hydraulic pressure is immediately transmitted to the wheel cylinders 40.

At this time, the simulator valve 54 is closed so that the hydraulic pressure transmitted to the wheel cylinder 40 through the first backup channel 251 is prevented from leaking to the reservoir 30 through the simulation device 50. The first dump valve 241 is kept closed to prevent the negative pressure of the first pressure chamber 112 from being transmitted to the reservoir 30.

Therefore, when the driver depresses the brake pedal 10, the hydraulic pressure discharged from the master cylinder 20 is transferred to the wheel cylinder 40 without loss, thereby ensuring stable braking.

However, when a leak occurs in the simulator valve 54, part of the hydraulic pressure discharged from the master cylinder 20 may be lost to the reservoir 30 through the simulator valve 54. [ The simulator valve 54 is provided to be closed in the abnormal mode. The hydraulic pressure discharged from the master cylinder 20 pushes the reaction force piston 52 of the simulation apparatus 50, The simulator valve 54 may leak.

In this way, when leakage occurs in the simulator valve 54, the driver does not obtain the intended braking force. Therefore, there is a problem in braking stability.

The inspection mode is a mode for checking whether a pressure is lost by generating a hydraulic pressure in the hydraulic pressure supply device 100 to check whether the simulator valve 54 is leaking. If the hydraulic pressure discharged from the hydraulic pressure supply device 100 flows into the reservoir 30 and pressure loss occurs, it is difficult to know whether or not the simulator valve 54 has leaked.

Therefore, in the inspection mode, the hydraulic circuit connected to the hydraulic pressure supply device 100 by closing the check valve 60 can be constituted by a closed circuit. That is, by closing the check valve 60, the simulator valve 54 and the outlet valve 222, the flow path connecting the hydraulic pressure supply device 100 and the reservoir 30 can be shut off to constitute a closed circuit.

The electronic brake system 1 according to the embodiment of the present invention provides the hydraulic pressure only to the first backup passage 251 to which the simulation apparatus 50 is connected among the first and second backup passages 251 and 252 in the inspection mode . Therefore, in order to prevent the hydraulic pressure discharged from the hydraulic pressure supply device 100 from being transmitted to the master cylinder 20 along the second backup channel 252, the second cut valve 262 is switched to the closed state in the inspection mode . The fifth control valve 235 for connecting the first hydraulic circuit 201 and the second hydraulic circuit 202 is kept closed and the fifth hydraulic fluid path 215 and the second hydraulic fluid path 212 are closed Closing of the sixth control valve 236 communicating with the second pressure chamber 113 prevents the hydraulic pressure of the second pressure chamber 113 from leaking to the first pressure chamber 112. [

Referring to FIG. 14, the inspection mode is a mode in which the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 221b, 221c, 221d and the second cut valve 262 are switched to the closed state and the first cut valve 261 and the third cut valve 262 are closed in the initial state of the first cut valve 241, The control valve 233 can be kept open and the hydraulic pressure generated by the hydraulic pressure supply device 100 can be transmitted to the master cylinder 20.

It is possible to prevent the hydraulic pressure of the hydraulic pressure supply device 100 from being transmitted to the first and second hydraulic circuits 201 and 202 by taking in the inlet valve 221 and to switch the second cut valve 262 to the closed state It is possible to prevent the hydraulic pressure of the hydraulic pressure supply device 100 from circulating along the first backup passage 251 and the second backup passage 252 and to switch the check valve 60 to the closed state, To the reservoir 30 can be prevented from leaking.

In the inspection mode, the electronic control unit analyzes the signal transmitted from the back-flow passage pressure sensor PS2 that measures the oil pressure of the master cylinder 20 after generating the hydraulic pressure in the hydraulic pressure supply device 100, It is possible to detect a state in which leakage occurs. For example, when there is no loss in the result of the measurement of the backup hydraulic pressure sensor PS2, it is determined that there is no leakage of the simulator valve 54, and when a loss occurs, it is determined that there is a leak in the simulator valve 54 .

FIG. 15 is a hydraulic circuit diagram showing a state in which the electromagnetic brake system 1 according to the embodiment of the present invention is operated in the retraction mode, and FIG. 16 is a diagram showing a state in which the drag phenomenon is eliminated.

In the retraction mode, after the initial start of the vehicle or after completion of braking, the hydraulic pressure supply device 100 is driven in the opposite direction (the depressurization direction) to form a negative pressure in the hydraulic line in the hydraulic control unit 200, The piston 41 is forcibly retreated to prevent abnormal contact between the disk 43 and the brake pad 42. [

After the piston 41 is retracted, as the disk 43 rotates, the brake pad 42 is moved in the piston direction, and a distance d between the disk 43 and the brake pad 42 is generated . Therefore, the drag phenomenon, which is a phenomenon in which the brake pad 42 contacts the disk 43 even after the braking is released, can be removed.

Referring to FIG. 15, the retraction mode can be performed regardless of the driver's will. That is, even when the driver does not operate the brake pedal 10, the electronic control unit rotates the motor 120 in the opposite direction to retract the hydraulic piston 114 and form a negative pressure in the first pressure chamber 112 The piston 41 of the wheel cylinder 40 can be retracted while the oil stored in the wheel cylinder 40 is sucked. At this time, the first dump valve 241 maintains the closed state to prevent the negative pressure of the first pressure chamber 112 from being transmitted to the reservoir 30.

10: Brake pedal 11: Pedal displacement sensor
20: master cylinder 30: reservoir
40: Wheel cylinder 50: Simulation device
54: simulator valve 60: check valve
100: hydraulic pressure supply device 110: hydraulic pressure supply unit
120: motor 130: power conversion section
200: Hydraulic control unit 201: First hydraulic circuit
202: second hydraulic circuit 211: first hydraulic oil
212: second hydraulic oil passage 213: third hydraulic oil passage
214: fourth hydraulic oil rail 215: fifth hydraulic oil rail
216: sixth hydraulic oil 217: seventh hydraulic oil
218: Eighth hydraulic oil passage 221: Inlet valve
222: outlet valve 223: check 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
241: first dump valve 242: second dump valve
243: Third dump valve 251: First backup channel
252: second backup passage 261: first cut valve
262: second cut valve

Claims (13)

A reservoir in which the oil is stored;
A hydraulic pressure supply device including a pressure chamber which is provided on one side of the hydraulic piston and is connected to at least one wheel cylinder, the hydraulic pressure piston being operated by an electric signal to generate a hydraulic pressure, the hydraulic pressure piston being accommodated movably in the cylinder block;
A hydraulic oil connecting the pressure chamber and the wheel cylinder; And
And a dump valve installed in a dump passage connecting the pressure chamber and the reservoir to control the flow of oil,
Wherein the dump valve is provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir. The method according to claim 1,
Wherein the dump valve is normally closed and is operated to open upon receipt of an open signal. The method according to claim 1,
Wherein the hydraulic pressure supply device includes a first pressure chamber located forward of the pressure direction of the hydraulic piston and a second pressure chamber located behind the hydraulic piston,
Wherein the hydraulic oil includes a first hydraulic oil passage communicated 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 oil passage communicated with the pressure chamber, a fifth hydraulic oil passage diverging from the fourth hydraulic oil passage and joining to the second hydraulic oil passage, and a fourth hydraulic oil passage branching from the fourth hydraulic oil passage and joining to the third hydraulic oil passage. 6 hydraulic oil furnace,
A first hydraulic circuit including first and second branch flow paths branched from the second hydraulic oil path so as to be respectively connected to two wheel cylinders;
And a second hydraulic circuit including third and fourth branch flow paths branched from the third hydraulic oil path so as to be connected to the two wheel cylinders, respectively. The method of claim 3,
A first control valve provided in the second hydraulic oil passage for controlling the flow of oil,
A second control valve provided in the third hydraulic oil passage for controlling the flow of oil,
Further comprising a third control valve provided in the fifth hydraulic oil passage for controlling the flow of oil,
Wherein at least one of the first to third control valves is provided with a check valve that allows the flow of oil in the direction from the hydraulic pressure supply device to the wheel cylinder and blocks the flow of oil in the opposite direction. 5. The method of claim 4,
Wherein the first and second control valves are provided as check valves which permit the flow of oil in the direction from the hydraulic pressure supply device to the wheel cylinder and shut off the flow of oil in the opposite direction,
And said third control valve is provided as a solenoid valve for controlling the flow of oil in both directions between said hydraulic pressure supply device and said wheel cylinder. The method of claim 3,
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 oil passage for controlling the flow of the oil. The method according to claim 6,
Wherein the fifth control valve is a normally closed type valve that is normally closed and operates to open upon receipt of an open signal. The method according to claim 6,
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 for controlling the flow of the oil. 9. The method of claim 8,
Wherein the sixth control valve is a normally closed type valve operative to normally open and open upon receipt of an open signal. The method of claim 3,
A first dump passage communicating with the first pressure chamber and connected to the reservoir,
A second dump passage communicating with the second pressure chamber and connected to the reservoir,
A first dump valve provided in the first dump passage to control the flow of oil and to control the flow of oil in both directions between the hydraulic pressure supply device and the reservoir;
And a second dump provided in the second dump passage to control the flow of the oil while allowing the flow of oil in the direction from the reservoir to the second pressure chamber while blocking the flow of oil in the opposite direction, A valve,
And a second dump valve for controlling the flow of oil in both directions between the reservoir and the second pressure chamber, And a third dump valve provided as a solenoid valve. 11. The method of claim 10,
Wherein the third dump valve is a normally open type valve that is normally open and operates to close upon receipt of a closing signal. A power conversion unit that converts the rotational force of the motor into a translational motion; a cylinder block that is connected to the power conversion unit and is movable within the cylinder block; A first pressure chamber provided at one side of the piston and connected to at least one wheel cylinder, and a second pressure chamber provided at the other side of the piston and connected to at least one wheel cylinder, ;
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 second hydraulic oil communicating with the first pressure chamber and providing a hydraulic pressure generated in the first pressure chamber to the wheel cylinder;
A third hydraulic oil communicating with the first pressure chamber and providing a hydraulic pressure generated in the first pressure chamber to the wheel cylinder;
A fifth hydraulic oil communicating with the second pressure chamber, joining the second hydraulic oil passage, and providing a hydraulic pressure generated in the second pressure chamber to the wheel cylinder;
A sixth hydraulic oil communicating with the second pressure chamber, joining the third hydraulic oil passage, and providing a hydraulic pressure generated in the second pressure chamber to the wheel cylinder;
A seventh hydraulic oil communicating the second hydraulic oil passage and the third hydraulic oil passage to communicate the hydraulic pressure of the wheel cylinder to the first pressure chamber;
An eighth hydraulic oil communicating the seventh hydraulic oil path with the second hydraulic oil or the third hydraulic oil path to transfer the hydraulic pressure of the wheel cylinder to the first pressure chamber;
A first dump valve provided in the first dump passage and provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir;
A first control valve provided in the second hydraulic oil passage for controlling the flow of oil;
A second control valve provided in the third hydraulic oil passage to control the flow of oil;
A third control valve provided in the fifth hydraulic oil passage and controlling the flow of the oil;
A fifth control valve provided in the seventh hydraulic oil passage or the eighth hydraulic oil passage for controlling the flow of oil;
A first hydraulic oil path including first and second branch flow paths branched from the first hydraulic fluid path to be connected to two wheel cylinders respectively and first and second inlet valves respectively controlling the first and second branch flow paths, circuit;
A second hydraulic circuit including third and fourth branch passages branched from the second hydraulic fluid passage to be connected to two wheel cylinders, respectively; And
And an electronic control unit (ECU) for controlling the operation of the motor and the opening and closing of the fifth control valve and the first through fourth inlet valves. brake pedal;
A reservoir in which the oil is stored;
A master cylinder having first and second hydraulic ports formed therein and connected to the reservoir and having one or more pistons to discharge oil according to the pressure of the brake pedal;
A pedal displacement sensor for sensing a displacement of the brake pedal;
A first backup oil channel connecting the first hydraulic port and the wheel cylinder;
A second backup oil channel connecting the second hydraulic port and the wheel cylinder;
A first cut valve provided in the first backup passage to control the flow of oil;
A second cut valve provided in the second backup passage to control the flow of oil;
A simulator provided in a flow path branched from the first backup passage and provided with a simulation chamber in which oil is received and a simulator valve provided in a flow path connecting the reservoir and providing a reaction force according to the power of the brake pedal;
The hydraulic piston being provided on one side of the hydraulic piston accommodated movably in the cylinder block so as to generate a hydraulic pressure or a negative pressure by advancing and retracting the hydraulic piston using the rotational force of the motor operated by the electric signal outputted from the pedal displacement sensor A hydraulic pressure supply device including a pressure chamber connected to at least one wheel cylinder;
A first hydraulic oil connected to the pressure chamber and joined to the first backup oil channel;
A second hydraulic oil connected to the pressure chamber and joined to the second backup channel;
And a hydraulic circuit connected to the first and second hydraulic oil passages and transmitting the hydraulic pressure discharged from the hydraulic pressure supply device to wheel cylinders provided to the wheels, A control unit;
An electronic control unit for controlling the motor and the valves based on the hydraulic pressure information and the displacement information of the brake pedal; And
And a dump valve installed in a dump passage connecting the pressure chamber and the reservoir to control the flow of oil,
The dump valve is provided as a solenoid valve for controlling the flow of oil in both directions between the hydraulic pressure supply device and the reservoir,
Wherein the electronic control unit retracts the hydraulic piston in a state in which the dump valve is closed to form a negative pressure in the pressure chamber and a negative pressure formed in the pressure chamber retracts the piston of the wheel cylinder.

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