KR102374888B1 - Electric brake system and method thereof - Google Patents

Abstract

The electromagnetic brake system includes a cylinder block in which an inner space is divided into a first pressure chamber and a second pressure chamber by a hydraulic piston, and a motor for moving the hydraulic piston forward or backward so that the volumes of the first pressure chamber and the second pressure chamber are different. and a control valve for opening and closing a hydraulic flow path connecting the first pressure chamber and the second pressure chamber, a temperature sensor for sensing the temperature of the motor, and an electronic control unit for controlling the motor and the control valve, the electronic control unit comprising: a low pressure mode in which hydraulic pressure is generated in one of the first and second pressure chambers by closing the control valve and moving the hydraulic piston, and the hydraulic pressure in the pressure chamber in which hydraulic pressure is generated by opening the control valve in the low pressure mode The high-pressure mode of introducing into another pressure chamber is selectively performed, but the transition from the low-pressure mode to the high-pressure mode is advanced based on the motor temperature sensed through the temperature sensor.

Description

Electronic brake system and control method thereof

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

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

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

In general, an electronic brake system includes a hydraulic pressure supply device for supplying pressure to wheel cylinders by receiving the driver's braking intention as an electrical signal from a pedal displacement sensor that senses the displacement of the brake pedal when the driver steps on the brake pedal.

The electronic brake system provided with the above hydraulic pressure supply device is disclosed in European Patent Registration No. EP 2 520 473. According to the disclosed document, the hydraulic pressure supply device is configured to generate a braking pressure by operating a motor according to a pedal force of a brake pedal. At this time, the braking pressure is generated by converting the rotational force of the motor into a linear motion and pressurizing the piston.

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

SUMMARY Embodiments of the present invention are to provide an electronic brake system including a hydraulic pressure supply device that operates in a double-acting manner.

In addition, it is intended to prevent a case in which the electronic brake system becomes high by estimating the temperature of the motor when a hydraulic pressure supply device operating in a double-acting type is included.

According to one aspect, the cylinder block inner space is divided into a first pressure chamber and a second pressure chamber by a hydraulic piston; a motor for advancing or reversing the hydraulic piston so that the volumes of the first pressure chamber and the second pressure chamber are different; a control valve for opening and closing a hydraulic flow path connecting the first pressure chamber and the second pressure chamber; a temperature sensor for sensing the temperature of the motor; and an electronic control unit controlling the motor and the control valve, wherein the electronic control unit closes the control valve and moves the hydraulic piston to generate hydraulic pressure in one of the first pressure chamber and the second pressure chamber Selectively perform a low-pressure mode to control the pressure, and a high-pressure mode in which the hydraulic pressure of the pressure chamber in which the hydraulic pressure is generated by opening the control valve in the low-pressure mode is introduced into another pressure chamber, but based on the motor temperature sensed through the temperature sensor An electronic brake system for advancing the transition from the low pressure mode to the high pressure mode may be provided.
The electronic control unit may advance the transition from the low pressure mode to the high pressure mode when the motor temperature is higher than the preset temperature than when the motor temperature is lower than the preset temperature.
The electronic control unit may reduce the pressure value for switching from the low-pressure mode to the high-pressure mode to advance the switching from the low-pressure mode to the high-pressure mode.
According to another aspect, the cylinder block inner space is divided into a first pressure chamber and a second pressure chamber by a hydraulic piston; a motor for advancing or reversing the hydraulic piston so that the volumes of the first pressure chamber and the second pressure chamber are different; In the control method of an electromagnetic brake system including a control valve for opening and closing a hydraulic flow path connecting the first pressure chamber and the second pressure chamber, the control valve is closed and the hydraulic piston is moved to close the first pressure chamber and a low pressure mode for generating hydraulic pressure in one of the second pressure chambers or a high pressure mode for opening the control valve in the low pressure mode to introduce the hydraulic pressure of the pressure chamber in which the hydraulic pressure is generated into the other pressure chamber, the There may be provided a control method of an electronic brake system that detects the temperature of the motor while performing the low pressure mode and advances the transition from the low pressure mode to the high pressure mode based on the sensed motor temperature.
The advancing the transition from the low pressure mode to the high pressure mode is to advance the transition from the low pressure mode to the high pressure mode when the motor temperature is higher than the preset temperature than when the motor temperature is lower than the preset temperature. may include
The hastening of the transition from the low pressure mode to the high pressure mode may include reducing a pressure value for switching from the low pressure mode to the high pressure mode to advance the transition from the low pressure mode to the high pressure mode.

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Embodiments of the present invention can provide hydraulic pressure more quickly and more precisely control the pressure increase by configuring the piston of the hydraulic pressure supply device in a double acting type.

In addition, by providing hydraulic or negative pressure by dividing the low-pressure section and the high-pressure section, it is possible to flexibly provide or release the braking force according to the braking situation.

In addition, 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.

In addition, it is possible to prevent the system from maintaining the high voltage state by estimating the temperature of the motor and lowering the amount of current of the motor by advancing the high voltage section in case of high pressure.

1 is a hydraulic circuit diagram showing a non-braking state of an electronic brake system according to an embodiment of the present invention.
2 is a schematic block diagram of an electronic brake system according to an embodiment of the present invention.
3 is a graph showing a motor current according to hydraulic pressure of the electronic brake system according to an embodiment of the present invention.
4 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston provides braking pressure in a low pressure mode while moving forward.
5 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston provides braking pressure in a high-pressure mode while moving forward.
6 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston provides braking pressure while moving backward.
7 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston releases the braking pressure while moving backward.
8 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston releases the braking pressure while moving forward.
9 is an operation flowchart of the electronic brake system according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the embodiments presented herein, and may be embodied in other forms. The drawings may omit the illustration of parts not related to the description in order to clarify the present invention, and slightly exaggerate the size of the components to help understanding.

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

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

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

Meanwhile, since the master cylinder 20 has two chambers, it is possible to secure 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. In this way, by independently configuring the two chambers, it is possible to make it possible to brake the vehicle even if one chamber fails.

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

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

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 while the first An elastic force is stored in the spring 21b and the second spring 22b. And when the force pushing the first piston 21a is smaller than the elastic force, the first and second pistons 21a and 22a are pushed back to their original state by using the stored elastic force of the first spring 21b and the second spring 22b. can

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

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

Referring to FIG. 1 , the simulation device 50 includes a simulation chamber 51 provided to store oil flowing out from the first hydraulic port 24a of the master cylinder 20 and a reaction force piston provided in the simulation chamber 51 ( 52) and a pedal simulator having a reaction force spring 53 elastically supporting it, and a simulator valve 54 connected to the rear end of the simulation chamber 51.

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

On the other hand, the reaction force spring 53 shown in the drawing is only one embodiment capable of providing an elastic force to the reaction force piston 52 , and may include various embodiments capable of storing the elastic force by shape deformation. For example, it includes various members capable of storing elastic force by being made of a material such as rubber, or having a coil or 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 may be connected to the master cylinder 20 , and the rear end of the simulation chamber 51 may be connected to the reservoir 30 through the simulator valve 54 . Accordingly, even when the reaction force piston 52 returns, the oil in the reservoir 30 flows in through the simulator valve 54 so that the entire interior of the simulation chamber 51 can be filled with oil.

On the other hand, several reservoirs 30 are shown in the drawings, and each of the reservoirs 30 uses the same reference numerals. However, these reservoirs may be provided with the same part or may be provided with different parts. For example, the reservoir 30 connected to the simulation device 50 may be the same as the reservoir 30 connected to the master cylinder 20 , or may store oil separately from the reservoir 30 connected to the master cylinder 20 . It can be a repository in

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

Also, a simulator check valve 55 may be installed between the pedal simulator and the reservoir 30 to be connected in parallel with the simulator valve 54 . The simulator check valve 55 allows the oil of the reservoir 30 to flow into the simulation chamber 51 , but the oil in the simulation chamber 51 flows into the reservoir 30 through the flow path in which the check valve 55 is installed. can block it Since oil can be supplied into the simulation chamber 51 through the simulator check valve 55 when the pedal pressure of the brake pedal 10 is released, a quick return of the pedal simulator pressure can be ensured.

The operation of the pedal simulation device 50 will be described. When the driver applies a pedal force to the brake pedal 10 , the reaction force piston 52 of the pedal simulator pushes the reaction force spring 53 while compressing the simulation chamber 51 . The oil inside is delivered to the reservoir 30 through the simulator valve 54, and in this process, the driver is provided with a feeling of pedal. And when the driver releases the pedaling force on the brake pedal 10, the reaction force spring 53 pushes the reaction force piston 52, and the reaction force piston 52 returns to its original state, and the oil in the reservoir 30 releases the simulator valve ( The oil may be filled in the simulation chamber 51 while flowing into the simulation chamber 51 through the flow path in which 54 is installed and the flow path in which the check valve 55 is installed.

As such, since the inside of the simulation chamber 51 is always filled with oil, friction of the reaction force piston 52 is minimized when the simulation device 50 is operated, so that the durability of the simulation device 50 is improved, as well as foreign substances from the outside. inflow may be blocked.

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

The electronic brake system 1 according to the embodiment of the present invention is a hydraulic pressure supply device 100 that receives the driver's braking intention as an electrical signal from the pedal displacement sensor 11 that detects the displacement of the brake pedal 10 and operates mechanically. ) and first and second hydraulic circuits 201 and 202 for controlling the flow of hydraulic pressure transmitted to the wheel cylinders 40 provided on the two wheels RR, RL, FR, and FL, respectively. 200 and a first cut valve 261 provided in the first backup flow path 251 connecting the first hydraulic port 24a and the first hydraulic circuit 201 to control the flow of hydraulic pressure, and the second A second cut valve 262 provided in the second backup flow path 252 connecting the hydraulic port 24b and the second hydraulic circuit 202 to control the flow of hydraulic pressure, hydraulic pressure information and pedal displacement information based on hydraulic pressure information It may include an electronic control unit 700 for controlling the supply device 100 and the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243 there is.

In addition, as the temperature sensor 1000 mounted on the coil unit of the motor 120 measures the temperature of the motor and transmits the temperature value to the electronic control unit 700, the electronic control unit 700 controls the motor when the temperature is high. By changing the operation to a high-pressure type, it is possible to prevent failure due to overload in the electromagnetic brake system 1 in advance.

This electronic control unit 700 can perform overall control of the electronic brake system 1, and the configuration of the electronic brake system 1 will be described in detail with reference to FIG. 2 .

1 again, the hydraulic pressure providing unit 110 includes a cylinder block 111 in which a pressure chamber to receive and store oil is formed, a hydraulic piston 114 accommodated in the cylinder block 111, and hydraulic pressure A sealing member (115: 115a, 115b) provided between the piston 114 and the cylinder block 111 to seal the pressure chamber, and connected to the rear end of the hydraulic piston 114, the power output from the power conversion unit 130 It includes a drive shaft 133 for transmitting to the hydraulic piston (114).

The pressure chamber is a first pressure chamber 112 positioned in front of the hydraulic piston 114 (in a forward direction, a left direction in the drawing), and a rear (reverse direction, a right direction in the drawing) of the hydraulic piston 114 (reverse direction, a right direction in the drawing). A second pressure chamber 113 may be included. That is, the first pressure chamber 112 is partitioned by the front end of the cylinder block 111 and the hydraulic piston 114 , and is provided to have a different volume according to the movement of the hydraulic piston 114 , and the second pressure chamber 113 . ) is partitioned by the rear end of the cylinder block 111 and the hydraulic piston 114 , and the volume is provided to vary according to the movement of the hydraulic piston 114 .

The first and second pressure chambers 112 and 113 are respectively connected to the reservoir 30 by the dump passages 116 and 117, and receive oil from the reservoir 30 and store it, or use the first or second pressure chamber ( Oils 112 and 113 may be transferred to the reservoir 30 . For example, the dump passages 116 and 117 are branched from the first pressure chamber 112 and connected to the reservoir 30 , and the dump passages 116 are branched from the second pressure chamber 113 and connected to the reservoir 30 . ) may include a second dump flow path 117 connected to the.

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

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

In addition, in the electromagnetic brake system 1 according to the embodiment of the present invention, a first control valve 231 and a second control valve ( 232) may be included.

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

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

In addition, the electromagnetic brake system 1 according to the embodiment of the present invention is provided in the fifth hydraulic flow path 215 and provided in the third control valve 233 and the sixth hydraulic flow path 216 to control the flow of oil. It may include 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 oil flow between the second pressure chamber 113 and the first hydraulic circuit 201 . In addition, the third control valve 233 may be provided as a normally closed type solenoid valve that is normally closed and operates to open when an open signal is received from the electronic control unit.

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 into the second pressure chamber 113 through the sixth hydraulic oil passage 216 and the fourth hydraulic oil passage 214 . can

In addition, the electronic 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. A fifth control valve 235 and a sixth control valve 236 provided in the eighth hydraulic oil passage 218 connecting the second hydraulic oil passage 212 and the seventh hydraulic oil passage 217 to control the flow of oil is included. can do. In addition, the fifth control valve 235 and the sixth control valve 236 are normally closed and may be provided as a normally closed type solenoid valve that operates to open the valve when an open signal is received from the electronic control unit. there is.

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

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

In addition, in the electromagnetic brake system 1 according to the embodiment of the present invention, a first dump valve 241 and a second dump valve 241 and second dump valves ( 242) may be further included. The dump valves 241 and 242 may be check valves that open only a direction from the reservoir 30 to the first or second pressure chambers 112 and 113 and close in the opposite direction. That is, the first dump valve 241 allows oil to flow from the reservoir 30 to the first pressure chamber 112, but blocks the flow of oil from the first pressure chamber 112 to the reservoir 30. It may be a check valve, and the second dump valve 242 allows oil to flow from the reservoir 30 to the second pressure chamber 113 , but the oil flows from the second pressure chamber 113 to the reservoir 30 . The flow may be a check valve shutting off.

In addition, the second dump flow path 117 may include a bypass flow path, and the bypass flow path includes a third dump valve 243 for controlling the oil flow 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 bidirectional flow, and is open in a normal state and operates to close the valve when it receives a closing signal from the electronic control unit (Normal Open) type) solenoid valve.

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

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

In addition, the negative pressure generated in the first pressure chamber 112 while the hydraulic piston 114 moves backward sucks the oil of the wheel cylinder 40 installed on the right front wheel FR and the left rear wheel LR to generate the first hydraulic circuit. 201 , the second hydraulic passage 212 , and the first hydraulic passage 211 through the first pressure chamber 112 , and the wheels installed on the right rear wheel RR and the left front wheel FL The oil in the cylinder 40 may be sucked and transferred to the first pressure chamber 112 through the second hydraulic circuit 202 , the third hydraulic passage 213 , and the first hydraulic passage 211 .

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

The motor 120 is a device for generating a rotational force in response to a signal output from the electronic control unit 700 , and may generate a rotational force in a forward or reverse direction. The rotation angular speed and rotation angle of the motor 120 may be precisely controlled. Since the motor 120 is a well-known technology, a detailed description thereof will be omitted.

On the other hand, the electronic control unit 170 includes the motor 120, and includes the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243). An operation in which the plurality of valves are controlled according to the displacement of the brake pedal 10 will be described later.

The driving force of the motor 120 generates displacement of the hydraulic piston 114 through the power conversion unit 130, and the hydraulic pressure generated while the hydraulic piston 114 slides within the pressure chamber is transferred to the first and second hydraulic flow paths. It is transmitted to the wheel cylinder 40 installed in each wheel (RR, RL, FR, FL) through (211, 212).

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

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

When the above operations are described again, a signal sensed by the pedal displacement sensor 11 is transmitted to the electronic control unit 700 while displacement occurs in the brake pedal 10 , and the electronic control unit 700 operates the motor 120 . is driven in one direction to rotate the worm shaft 131 in one direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 via the worm wheel 132 , and the hydraulic piston 114 connected to the drive shaft 133 moves forward to generate hydraulic pressure in the first pressure chamber 112 .

Conversely, when the pedal force is removed from the brake pedal 10 , the electronic control unit 700 drives the motor 120 in the opposite direction to rotate the worm shaft 131 in the opposite direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and the hydraulic piston 114 connected to the drive shaft 133 returns (moves backward) to generate negative pressure in the first pressure chamber 112 .

On the other hand, the generation of hydraulic pressure and negative pressure is also possible in the direction opposite to the above. That is, while displacement occurs in the brake pedal 10 , the signal sensed by the pedal displacement sensor 11 is transmitted to the electronic control unit 700 , and the electronic control unit 700 drives the motor 120 in the opposite direction. to rotate the worm shaft 131 in the opposite direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 via the worm wheel 132 , and the hydraulic piston 114 connected to the drive shaft 133 moves backward to generate hydraulic pressure in the second pressure chamber 113 .

Conversely, when the pedal force is removed from the brake pedal 10 , the electronic control unit 700 drives the motor 120 in one direction to rotate the worm shaft 131 in one direction. Accordingly, the worm wheel 132 also rotates in the opposite direction and the hydraulic piston 114 connected to the drive shaft 133 returns (moves forward) to generate a negative pressure in the second pressure chamber 113 .

As such, the hydraulic pressure supply device 100 serves to transmit the hydraulic pressure to the wheel cylinder 40 or suck the hydraulic pressure to the reservoir 30 according to the rotation direction of the rotational force generated from the motor 120 .

On the other hand, when the motor 120 rotates in one direction, hydraulic pressure may be generated in the first pressure chamber 112 or negative pressure may be generated in the second pressure chamber 113 . Whether to brake using hydraulic pressure, or negative pressure Whether to release the braking using can be decided. This will be described in detail later.

And, it should be understood that the power conversion unit 130 according to the embodiment of the present invention can be employed in any structure as long as it can convert rotational motion into linear motion other than the structure of the ball screw nut assembly.

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

In addition, the first and second cut valves 261 and 262 may be provided as a solenoid valve of a normally open type that is opened in a normal state and operates to close the valve when a closing signal is received from the electronic control unit. there is.

Next, the hydraulic control unit 200 according to the embodiment of the present invention will be described with reference to FIG. 1 .

The hydraulic control unit 200 may include a first hydraulic circuit 201 and a second hydraulic circuit 202 that receive hydraulic pressure to control two wheels, respectively. For example, the first hydraulic circuit 201 may control the right front wheel FR and the left rear wheel RL, and the second hydraulic circuit 202 may control the left front wheel FL and the right rear wheel RR. . In addition, a wheel cylinder 40 is installed on each of the wheels FR, FL, RR, and RL to receive hydraulic pressure to perform braking.

The first hydraulic circuit 201 is connected to the first hydraulic passage 211 and the second hydraulic passage 212 to receive hydraulic pressure from the hydraulic pressure supply device 100 , and the second hydraulic passage 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 passage 211 and the third hydraulic oil passage 213 to receive hydraulic pressure from the hydraulic pressure supply device 100 , and the third hydraulic oil passage 213 is the left front wheel. It branches into two flow paths connected to (FL) and the right rear wheel (RR).

The hydraulic circuits 201 and 202 may include a plurality of inlet valves 221 (221a, 221b, 221c, 221d) to control the flow of hydraulic pressure. For example, the first hydraulic circuit 201 may be provided with two inlet valves 221a and 221b connected to the first hydraulic flow path 211 to respectively control the hydraulic pressure transmitted to the two wheel cylinders 40 . . In addition, the second hydraulic circuit 202 may be provided with two inlet valves 221c and 221d connected to the second hydraulic oil passage 212 to respectively control the hydraulic pressure transmitted to the wheel cylinder 40 .

And the inlet valve 221 is disposed on the upstream side of the wheel cylinder 40, is open in a normal state, and operates to close the valve when a closing signal is received from the electronic control unit 700 (Normal Open type) It may be provided as a solenoid valve of

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

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

In addition, the outlet valve 222 may be provided as a normally closed solenoid valve that is normally closed and operates to open when an open signal is received from the electronic control unit.

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

At this time, the first backup flow passage 251 may join the first hydraulic circuit 201 upstream of the first and second inlet valves 221a and 221b. Similarly, the second backup flow path 252 may join the second hydraulic circuit 202 upstream of the third and fourth inlet valves 221c and 221d. Therefore, when the first and second cut valves 261 and 262 are closed, the hydraulic pressure provided from the hydraulic pressure supply device 100 is supplied to the wheel cylinder 40 through the first and second hydraulic circuits 201 and 202. When the first and second cut valves 261 and 262 are opened, the hydraulic pressure provided from the master cylinder 20 is supplied to the wheel cylinder 40 through the first and second backup passages 251 and 252. can At this time, since the plurality of inlet valves 221a, 221b, 221c, and 221d are in an open state, it is not necessary to change the operating state.

Meanwhile, an undescribed reference numeral “MPS” denotes a motor control sensor that controls a rotation angle of the motor 120 or a current of the motor.

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

First, FIG. 2 is a block diagram showing the configuration of an electronic brake system according to the present invention.

As shown in FIG. 2 , the electronic brake system 1 according to the present invention is capable of controlling a plurality of valves in the hydraulic pressure supply device 100 and the hydraulic pressure control unit 200 shown in FIG. 1 , and a temperature sensor It includes a unit 500 , a pressure measuring unit 600 , an electronic control unit 700 , a motor 120 , and a plurality of valves 800 .

The temperature sensor unit 500 includes a temperature sensor 1000 mounted on the coil unit of the motor 120 shown in FIG. 1 , and measures the temperature of the motor 120 in real time.

The pressure measuring unit 600 measures the hydraulic pressure in the electronic brake system 1 , and may include a plurality of pressure sensors.

Specifically, the pressure of each wheel may be measured through a pressure sensor (not shown) included in each wheel FR, FL, RR, and RL, and the pressure value may be transmitted to the electronic control unit 20, as shown in FIG. The illustrated PS1 is a hydraulic oil pressure sensor that senses the hydraulic pressure of the hydraulic circuits 201 and 202 and measures the hydraulic pressure of the hydraulic pressure, and PS2 is a backup passage pressure sensor that measures the oil pressure of the master cylinder 20. The hydraulic pressure of the master cylinder can be measured.

Next, the electronic control unit 700 controls the electronic brake system 1 of the vehicle according to the present invention as a whole, and controls the hydraulic pressure supply device 100 to operate separately in a low pressure mode or a high pressure mode, and the temperature It includes a main processor 710 that controls the operation of the hydraulic pressure supply device 100 according to the temperature measured by the sensor unit 500 and a memory 720 that stores various data.

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

In more detail, the hydraulic piston 114 generates hydraulic pressure in the first pressure chamber 112 while advancing. As the hydraulic piston 114 advances from the initial state, that is, as the stroke of the hydraulic piston 114 increases, the amount of oil transferred from the first pressure chamber 112 to the wheel cylinder 40 increases and the braking pressure decreases. rises 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, in the high pressure mode, the pressure increase rate per stroke of the hydraulic piston 114 is small compared to the low pressure mode. This is because not all of the oil pushed out from the first pressure chamber 112 flows into the wheel cylinder 40 , but some flows into the second pressure chamber 113 . This will be described in detail with reference to FIG. 4 .

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

However, there is a problem in that the temperature of the electronic brake system 1 increases due to a large amount of current in the motor 120 when operating in the low pressure mode. Accordingly, the electronic control unit 700 may control the hydraulic pressure supply device 100 to enter the high-pressure mode early when the temperature of the motor 120 exceeds a preset threshold value.

That is, the main processor 710 in the electronic control unit 700 performs overall control of the electronic brake system 1 according to the present invention, and the main processor 710 includes hydraulic oil installed in the second hydraulic oil passage 212 . By controlling the hydraulic pressure supply device 100 according to the output of the pressure sensor detected by the furnace pressure sensor PS1, the flow rate transmitted to the wheel cylinder 40 may be controlled.

Specifically, FIG. 3 is a graph schematically showing the operation of the electronic brake system 1 according to the present invention.

The graph shown by the thin solid line 61 shows that when the temperature of the motor measured by the temperature sensor unit 500 is less than a preset threshold value (the first threshold value), the low-pressure mode is switched from the low-pressure mode to the high-pressure mode when the P _N pressure is reached. In the graph shown by a thick solid line 62, when the temperature of the motor measured by the temperature sensor unit 500 is greater than or equal to a preset threshold value (second threshold value), the pressure value smaller than P _N is When _PC is reached, it is switched from low pressure mode to high pressure mode.

That is, before the hydraulic piston 114 advances to the maximum, when the pressure measured by the hydraulic flow path pressure sensor PS1 reaches a preset critical pressure P _N , shown in FIG. 5 in the low pressure mode shown in FIG. 4 to be described later. It can be switched to high-pressure mode.

Accordingly, it is possible to prevent overload of the electronic brake system 1 due to an overload of the motor 120 when operating in the low pressure mode.

Next, the operation of the plurality of valves 800 including the motor 120 in the low pressure mode and the high pressure mode will be described later with reference to FIGS. 4 to 8 .

4 shows a situation in which the hydraulic piston 114 advances and provides braking pressure in the low pressure mode, FIG. 5 shows a situation in which the hydraulic piston 114 advances and provides braking pressure in the high pressure mode, and FIG. FIG. 7 is a hydraulic circuit diagram illustrating a situation in which braking pressure is provided while moving backward, FIG. 7 is a situation in which the hydraulic piston releases braking pressure while moving backward, and FIG. 8 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston releases braking pressure while moving forward.

First, referring to FIG. 4 , when braking by the driver is started, the amount of braking required by the driver may be sensed through information such as the pressure of the brake pedal 10 that the driver presses through the pedal displacement sensor 11 . The electronic control unit 700 receives the electrical signal output from the pedal displacement sensor 11 to drive the motor 120 .

In addition, the electronic control unit 700 is the size of the amount of regenerative braking through the backup flow path pressure sensor PS2 provided on the outlet side of the master cylinder 20 and the hydraulic pressure flow path pressure sensor PS1 provided on the second hydraulic circuit 202 . is input, and the magnitude of the friction braking amount is calculated according to the difference between the driver's required braking amount and the regenerative braking amount, and thus the pressure increase or pressure reduction level of the wheel cylinder 40 may be grasped.

Referring to FIG. 4 , when the driver steps on the brake pedal 10 at the initial stage of braking, the motor 120 operates to rotate in one direction, and the rotational force of the motor 120 is transferred to the hydraulic pressure providing unit by the power transmission unit 130 . It is transmitted to 110 , and the hydraulic piston 114 of the hydraulic pressure providing unit 110 advances to generate 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 in each of the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate braking force.

Specifically, the hydraulic pressure provided from the first pressure chamber 112 is directly applied to the wheel cylinder 40 provided on the two wheels FR and RL through the first hydraulic oil passage 211 and the second hydraulic oil passage 212 . is transmitted At this time, the first and second inlet valves 221a and 221b respectively installed in two flow passages branching from the second hydraulic oil passage 212 are provided in an open state. In addition, the first and second outlet valves 222a and 222b installed in the flow passages respectively branching from the two oil passages branching from the second hydraulic oil passage 212 are maintained in a closed state to prevent the hydraulic pressure from leaking to the reservoir 30 . block

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

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

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

In addition, when the pressure transmitted to the wheel cylinder 40 is measured to be higher than the target pressure value according to the pedal effort of the brake pedal 10 , the electronic control unit 700 detects any one of the first to fourth outlet valves 222 . By opening the ideal, it can be controlled to follow the target pressure value.

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

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

In addition, the hydraulic oil pressure sensor PS1 installed in the second hydraulic oil passage 212 is a wheel cylinder 40 installed in the left front wheel FL or the right rear wheel RR (hereinafter simply referred to as the wheel cylinder 40). It is possible to detect the flow rate delivered to Accordingly, by controlling the hydraulic pressure supply device 100 according to the output of the hydraulic oil pressure sensor PS1, the flow rate transmitted to the wheel cylinder 40 can be controlled. Specifically, the flow rate and discharge speed discharged from the wheel cylinder 40 may be controlled by adjusting the forward distance and forward speed of the hydraulic piston 114 .

On the other hand, when the pressure measured by the hydraulic flow path pressure sensor PS1 reaches a preset critical pressure P _N before the hydraulic piston 114 advances to the maximum, the high pressure mode shown in FIG. 5 in the low pressure mode shown in 4 can be converted to

However, when the temperature of the motor 120 exceeds the preset temperature (first threshold) and exceeds the preset threshold pressure (P _N ), when Pc is reached, the low pressure mode shown in FIG. It can be switched to high pressure mode.

Referring to FIG. 5 , in the high pressure mode, the third control valve 233 may be switched to an open state to open the fifth hydraulic flow path 215 . Therefore, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the second pressure chamber 113 through the fifth hydraulic passage 215 connected to the second hydraulic passage 212 to push the hydraulic piston 114 . can be used

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

6 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston 114 provides braking pressure while moving backward.

Referring to FIG. 6 , when the driver steps on the brake pedal 10 at the initial stage of braking, the motor 120 operates to rotate in the opposite direction, and the rotational force of the motor 120 is transferred to the hydraulic pressure providing unit by the power transmission unit 130 . It is transmitted to 110 , and the hydraulic piston 114 of the hydraulic pressure providing unit 110 moves backward to generate 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 in each of the four wheels through the first hydraulic circuit 201 and the second hydraulic circuit 202 to generate braking force.

Specifically, the hydraulic pressure provided from the second pressure chamber 113 is directly applied to the wheel cylinder 40 provided in the two wheels FR and RL through the fourth hydraulic flow path 214 and the fifth hydraulic flow path 215 . is transmitted In addition, the first and second outlet valves 222a and 222b installed in the flow passages respectively branching from the two oil passages branching from the second hydraulic oil passage 212 are maintained in a closed state to prevent the hydraulic pressure from leaking to the reservoir 30 . block

And the hydraulic pressure provided from the second pressure chamber 113 is directly transmitted to the wheel cylinder 40 provided in the two wheels RR, FL through the fourth hydraulic flow path 214 and the sixth hydraulic flow path 216 . . At this time, the third and fourth inlet valves 221c and 221d respectively installed in two flow passages branching from the sixth hydraulic flow passage 216 are provided in an open state. In addition, the third and fourth outlet valves 222c and 222d installed in the flow passages respectively branching from the two flow passages branching from the sixth hydraulic oil passage 216 are maintained in a closed state to prevent the hydraulic pressure from leaking to the reservoir 30 . block

And the third control valve 233 is switched to the open state to open the fifth hydraulic flow path (215). Meanwhile, since the fourth control valve 234 is provided as a check valve that allows hydraulic pressure transmission in the direction of the wheel cylinder 40 from the second pressure chamber 113 , the sixth hydraulic flow path 216 is opened.

And the sixth control valve 236 may be maintained in a closed state to block the eighth hydraulic flow path 218 . By preventing the hydraulic pressure generated in the second pressure chamber 113 from being transmitted to the first pressure chamber 112 through the eighth hydraulic passage 218 connected to the fifth hydraulic passage 215, the pressure increase rate per stroke can be improved. there is. Therefore, a quick braking response can be expected at the beginning of braking.

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

7 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston 114 releases the braking pressure while moving backward, and FIG. 8 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston 114 releases the braking pressure while moving forward.

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

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

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

And instead of closing or switching the third control valve 233 to the closed state to close the fifth hydraulic flow path 215 , the third dump valve 243 is switched or maintained to the open state to close the second pressure chamber 113 . It can be connected 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 reduction rate per stroke of the hydraulic piston 114 is increased compared to the high pressure mode.

Unlike FIG. 7 , when the hydraulic piston 114 moves in the opposite direction, that is, even when it moves forward, the braking force of the wheel cylinder 40 can be released.

8 is a hydraulic circuit diagram illustrating a situation in which the hydraulic piston releases braking pressure while moving forward.

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 during braking and transmits it to the power conversion unit 130 , and a worm of the power conversion unit 130 . The shaft 131, the worm wheel 132, and the drive shaft 133 rotate in the opposite direction during braking to advance the hydraulic piston 114 to its original position to release the pressure in the second pressure chamber 113 or to release the negative pressure. generate In addition, the hydraulic pressure providing unit 110 receives the hydraulic pressure discharged from the wheel cylinder 40 through the first and second hydraulic circuits 201 and 202 and transmits it to the second pressure chamber 113 .

Specifically, the negative pressure generated in the second pressure chamber 113 is through the fourth hydraulic passage 214, the fifth hydraulic passage 215, and the second hydraulic passage 212 connected to the second communication hole 111b. Release the pressure of the wheel cylinder 40 provided on the two wheels (FR, RL). At this time, the first and second inlet valves 221a and 221b respectively installed in two flow passages branching from the second hydraulic oil passage 212 are provided in an open state. In addition, the first and second outlet valves 222a and 222b installed in the flow passages respectively branching from the two oil passages branching from the second hydraulic oil passage 212 are maintained in a closed state to prevent the inflow of oil from the reservoir 30 . block

And the negative pressure generated in the second pressure chamber 113 is a fourth hydraulic oil passage 214, a fifth hydraulic oil passage 215, a seventh hydraulic oil passage 217, and a third hydraulic oil connected to the second communication hole 111b. The pressure of the wheel cylinder 40 provided on the two wheels FL and RR is released through the furnace 213 . At this time, the third and fourth inlet valves 221c and 221d respectively installed in two flow passages branching from the third hydraulic flow passage 216 are provided in an open state. In addition, the third and fourth outlet valves 222c and 222d installed in the flow paths branching from the two flow paths branching from the third hydraulic flow path 213 are maintained in a closed state to prevent the inflow of oil from the reservoir 30 . block

In addition, the third control valve 233 may be switched to an open state to open the fifth hydraulic flow path 215 , and the fifth control valve 235 may be switched to an open state to open the seventh hydraulic flow path 217 . .

In addition, 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 according to the release amount of the brake pedal 10 , among the first to fourth outlet valves 222 , Any one or more may be opened and controlled to follow the target pressure value.

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

In addition, the hydraulic oil pressure sensor PS1 installed in the second hydraulic oil passage 212 may detect a flow rate discharged from the wheel cylinder 40 installed in the left front wheel FL or the right rear wheel RR. Therefore, by controlling the hydraulic pressure supply device 100 according to the output of the hydraulic pressure sensor PS1, the flow rate discharged from the wheel cylinder 40 can be controlled. Specifically, the flow rate and discharge speed discharged from the wheel cylinder 40 may be controlled by adjusting the forward distance and forward speed of the hydraulic piston 114 .

In the above, the operation in the low pressure mode and the high pressure mode was examined by controlling the motor 120 and the plurality of valves 800 according to the control signal of the main processor 710 in the electronic control unit 700 .

Next, the memory 720 in the electronic control unit 700 is a volatile memory such as S-RAM and D-RAM, as well as flash memory, ROM (Read Only Memory), ePROM ( It may include a nonvolatile memory such as an Erasable Programmable Read Only Memory (EPROM) and an Electrically Erasable Programmable Read Only Memory (EEPROM).

The non-volatile memory may semi-permanently store a control program and control data for controlling the operation of the electronic brake system 1, and the volatile memory fetches and temporarily stores the control program and control data from the non-volatile memory, and various Sensor information and various control signals output from the main processor may be temporarily stored.

In the above, the configuration of the electromagnetic brake system 1 according to the present invention has been described.

9 is a flowchart of a control method of the electronic brake system 1 according to the present invention.

The electronic brake system 1 according to the present invention measures the temperature of the motor 120 . Specifically, the temperature of the motor 120 may be measured in real time through the temperature sensor 1000 included in the temperature sensor unit 500 of the electronic brake system 1 .

In addition, the electronic brake system 1 according to the present invention measures the hydraulic pressure in the circuit. Specifically, the pressure measuring unit 600 of the electronic brake system 1 includes a plurality of pressure sensors, and specifically, the PS1 pressure sensor shown in FIG. 1 is hydraulic oil for sensing the hydraulic pressure of the hydraulic circuits 201 and 202 . The pressure sensor can measure the hydraulic pressure of hydraulic pressure.

Next, the electronic brake system 1 according to the present invention operates when braking control is started, and when the temperature of the motor 120 measured through the temperature sensor 1000 is lower than a preset first threshold, the electronic The control unit 700 is in a normal state, and the pressure value of PS1 is P _N When it exceeds, the low pressure mode is changed to the high pressure mode.

However, when the temperature of the motor 120 measured through the temperature sensor 1000 is higher than the first threshold value set in advance, the electronic control unit 700 sets the pressure of PS1 to a pressure value lower than P _N in order to lower the motor load. When Pc is reached, the low-pressure mode is changed to the high-pressure mode.

In the above, one embodiment of the disclosed invention has been illustrated and described, but the disclosed invention is not limited to the specific embodiments described above, and those of ordinary skill in the art to which the disclosed invention belongs without departing from the gist of the claims Various modifications are possible, of course, and these modifications cannot be individually understood from the disclosed invention.

10: brake pedal 11: pedal displacement sensor
20: master cylinder 30: reservoir
40: wheel cylinder 50: simulation device
54: simulator valve 60: inspection valve
100: hydraulic supply 110: hydraulic supply unit
120: motor 130: power conversion unit
200: hydraulic control unit 201: first hydraulic circuit
202: second hydraulic circuit 211: first hydraulic flow path
212: second hydraulic flow path 213: third hydraulic flow path
214: fourth hydraulic flow path 215: fifth hydraulic flow path
216: 6th hydraulic flow path 217: 7th hydraulic flow path
218: eighth hydraulic flow path 221: inlet valve
222: outlet valve 223: check valve
231: first control valve 232: second control valve
233: 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 flow path
252: second backup flow path 261: first cut valve
262: second cut valve

Claims (12)

delete delete delete delete delete delete ◈Claim 7 was abandoned at the time of payment of the registration fee.◈ a cylinder block in which an inner space is divided into a first pressure chamber and a second pressure chamber by a hydraulic piston;
a motor for advancing or reversing the hydraulic piston so that the volumes of the first pressure chamber and the second pressure chamber are different;
a control valve for opening and closing a hydraulic flow path connecting the first pressure chamber and the second pressure chamber;
a temperature sensor for sensing the temperature of the motor; and
An electronic control unit for controlling the motor and the control valve,
The electronic control unit closes the control valve and moves the hydraulic piston to generate hydraulic pressure in one of the first pressure chamber and the second pressure chamber; An electronic brake system that selectively performs a high-pressure mode for introducing the generated hydraulic pressure of the pressure chamber into another pressure chamber, and advances the transition from the low-pressure mode to the high-pressure mode based on the motor temperature sensed through the temperature sensor . ◈Claim 8 was abandoned at the time of payment of the registration fee.◈ 8. The method of claim 7,
The electronic control unit advances the transition from the low pressure mode to the high pressure mode when the motor temperature is higher than a preset temperature than when the motor temperature is lower than the preset temperature. ◈Claim 9 was abandoned when paying the registration fee.◈ 9. The method of claim 8,
and the electronic control unit reduces a pressure value for switching from the low pressure mode to the high pressure mode to advance the transition from the low pressure mode to the high pressure mode. a cylinder block in which an inner space is divided into a first pressure chamber and a second pressure chamber by a hydraulic piston; a motor for advancing or reversing the hydraulic piston so that the volumes of the first pressure chamber and the second pressure chamber are different; In the control method of an electromagnetic brake system comprising a control valve for opening and closing a hydraulic flow passage connecting the first pressure chamber and the second pressure chamber,
of the pressure chamber in which hydraulic pressure is generated by closing the control valve and opening the control valve in the low pressure mode or the low pressure mode in which hydraulic pressure is generated in one of the first pressure chamber and the second pressure chamber by moving the hydraulic piston Selectively perform a high-pressure mode that introduces hydraulic pressure into another pressure chamber,
Sensing the temperature of the motor while performing the low pressure mode,
A control method of an electronic brake system for advancing the transition from the low pressure mode to the high pressure mode based on the sensed motor temperature. 11. The method of claim 10,
Accelerating the transition from the low-pressure mode to the high-pressure mode is,
When the motor temperature is higher than a preset temperature, the control method of the electronic brake system comprising advancing the transition from the low pressure mode to the high pressure mode than when the motor temperature is lower than the preset temperature. 12. The method of claim 11,
Accelerating the transition from the low-pressure mode to the high-pressure mode is,
and reducing the pressure value for switching from the low pressure mode to the high pressure mode to advance the transition from the low pressure mode to the high pressure mode.

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