KR102576408B1 - Electric brake system - Google Patents

Abstract

An electronic brake system is disclosed. An electronic brake system according to an embodiment of the present invention includes a master cylinder connected to a reservoir, having first and second master chambers, first and second pistons, and discharging braking fluid according to the pedal pressure, and an electrical signal. A hydraulic pressure supply device that operates to generate hydraulic pressure, a hydraulic control unit including a first hydraulic circuit and a second hydraulic circuit, and first to first to second hydraulic control units installed on the upstream side of each wheel cylinder to selectively open and close the flow path. A fourth inlet valve, a first backup passage connecting the first master chamber and the first hydraulic circuit, a second backup passage connecting the second master chamber and the second hydraulic circuit, and the first and backup passages are selectively selected. It includes first and second cut valves that open and close, and the first hydraulic circuit includes a first branch passage in which the first inlet valve is installed, a second branch passage in which the second inlet valve is installed, the first branch passage and the first branch passage. It includes a first circuit passage connecting two branch passages, and the second hydraulic circuit includes a third branch passage in which a third inlet valve is installed, a fourth branch passage in which a fourth inlet valve is installed, and a third branch passage. It includes a second circuit flow path connecting the fourth branch flow path.

Description

Electronic brake system {Electric brake system}

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

Vehicles are essentially equipped with a brake system for braking, and recently, various types of systems have been proposed to achieve stronger and more stable braking force.

Examples of brake systems include the Anti-Lock Brake System (ABS), which prevents wheel slippage during braking, and the Brake Traction Control System (BTCS: Brake System), which prevents slippage of the driving wheels when the vehicle suddenly starts or accelerates. Traction Control System) and Electronic Stability Control System (ESC), which keep the vehicle's driving condition stable by controlling brake fluid pressure by combining an anti-lock brake system and traction control.

In general, an electronic brake system includes a hydraulic pressure supply device that receives the driver's intention to brake as an electrical signal from a pedal displacement sensor that detects the displacement of the brake pedal when the driver steps on the brake pedal and supplies pressure to the wheel cylinder.

An electronic brake system equipped with the above hydraulic pressure supply device is disclosed in European registered patent EP 2 520 473. According to the disclosed literature, the hydraulic pressure supply device is configured such that a motor operates according to the pedal pressure of the brake pedal to generate braking pressure. At this time, braking pressure is generated by converting the rotational force of the motor into linear motion and pressurizing the piston.

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

Embodiments of the present invention are intended to provide an electronic brake system in which hydraulic pressure of a master cylinder can be transmitted to some of a plurality of wheel cylinders during basic braking.

According to one aspect of the present invention, it is connected to a reservoir in which braking fluid is stored, and is provided with first and second master chambers and first and second pistons provided in each master chamber to pump braking fluid according to the pedal force of the brake pedal. Discharging master cylinder; A hydraulic pressure supply device that operates by electrical signals to generate hydraulic pressure; The hydraulic pressure discharged from the hydraulic pressure supply device is transmitted to wheel cylinders provided on each wheel, and a first hydraulic circuit includes a passage connected to some of the wheel cylinders and a second hydraulic circuit includes a passage connected to other portions of the wheel cylinders. A hydraulic control unit having a hydraulic circuit; First to fourth inlet valves installed on the upstream side of each wheel cylinder to selectively open and close the flow path; a first backup passage connecting the first master chamber and the first hydraulic circuit; a second backup passage connecting the second master chamber and the second hydraulic circuit; a first cut valve that selectively opens and closes the first backup passage; and a second cut valve that selectively opens and closes the second backup passage, wherein the first hydraulic circuit includes a first branch passage in which the first inlet valve is installed, and a second branch in which the second inlet valve is installed. It includes a flow path and a first circuit flow path connecting the first branch flow path and the second branch flow path, wherein the second hydraulic circuit includes a third branch flow path in which the third inlet valve is installed, and the fourth inlet valve. An electromagnetic brake system may be provided including a fourth branch flow path in which is installed, and a second circuit flow path connecting the third branch flow path and the fourth branch flow path.

Additionally, the first backup passage may be directly connected to the first branch passage, and the second backup passage may be directly connected to the fourth branch passage.

In addition, it may further include a third cut valve installed in the first circuit flow path to control the flow of braking fluid, and a fourth cut valve installed in the second circuit flow path to control the flow of braking fluid.

Additionally, the third and fourth cut valves may be normally open type valves that are normally open and operate to close when a closing signal is received.

In addition, it further includes a pedal displacement sensor that outputs an electrical signal in response to displacement of the brake pedal, and the hydraulic pressure supply device may be operated by an electrical signal from the pedal displacement sensor.

In addition, the hydraulic pressure supply device generates hydraulic pressure using a piston that operates by an electrical signal output in response to the displacement of the brake pedal, and is provided on one side of the piston movably accommodated inside the cylinder block and has one or more It includes a first pressure chamber connected to the wheel cylinder and a second pressure chamber provided on the other side of the piston and connected to one or more wheel cylinders, a first hydraulic oil passage in communication with the first pressure chamber, and the first hydraulic oil. It may further include second and third hydraulic passages branching from the furnace, wherein the second hydraulic passage may be connected to the first hydraulic circuit, and the third hydraulic passage may be connected to the second hydraulic circuit.

In addition, a fourth hydraulic oil passage in communication with the second pressure chamber, a fifth hydraulic oil path branched from the fourth hydraulic oil passage and joining the second hydraulic oil passage, and a fifth hydraulic oil passage branched from the fourth hydraulic oil passage and connected to the third hydraulic oil passage. It may further include a sixth hydraulic oil path joining the furnace.

In addition, the hydraulic pressure supply device includes a motor that operates by an electrical signal output in response to the displacement of the brake pedal, a power conversion unit that converts the rotational force of the motor into translational movement, a cylinder block, and the power conversion unit. A piston that is connected and movably accommodated inside the cylinder block, a first pressure chamber provided on one side of the piston and connected to one or more wheel cylinders, and a second pressure chamber provided on the other side of the piston and connected to one or more wheel cylinders. A hydraulic pressure supply device including a pressure chamber; a second hydraulic oil passage that communicates with the first pressure chamber and provides hydraulic pressure generated in the first pressure chamber to the wheel cylinder; a third hydraulic oil passage that communicates with the first pressure chamber and provides hydraulic pressure generated in the first pressure chamber to the wheel cylinder; a fifth hydraulic passage that communicates with the second pressure chamber, joins the second hydraulic passage, and provides hydraulic pressure generated in the second pressure chamber to the wheel cylinder; a sixth hydraulic passage that communicates with the second pressure chamber, joins the third hydraulic passage, and provides hydraulic pressure generated in the second pressure chamber to the wheel cylinder; a seventh hydraulic oil passage communicating with the second hydraulic oil passage and the third hydraulic oil passage to transfer the hydraulic pressure of the wheel cylinder to the first pressure chamber; an eighth hydraulic oil passage communicating with the seventh hydraulic oil passage and the second hydraulic oil passage or the third hydraulic oil passage to transfer the hydraulic pressure of the wheel cylinder to the first pressure chamber; a first control valve provided in the second hydraulic passage to control the flow of braking fluid; a second control valve provided in the third hydraulic passage to control the flow of braking fluid; a third control valve provided in the fifth hydraulic passage to control the flow of braking fluid; a fifth control valve provided in the seventh hydraulic oil passage or the eighth hydraulic oil passage to control the flow of braking fluid; And it may include an electronic control unit (ECU) that controls the operation of the motor and the opening and closing of the first to fourth inlet valves.

In addition, the first branch passage directly connected to the first backup passage and the fourth branch passage directly connected to the second backup passage are connected to a wheel cylinder provided on either the front wheel or the rear wheel, and the first branch passage is connected to the first backup passage. The second branch passage connected to the backup passage through the first circuit passage and the third branch passage connected to the second backup passage through the second circuit passage are wheel cylinders provided on the other of the front wheels or rear wheels. can be connected to

According to another aspect of the present invention, it is connected to a reservoir in which braking fluid is stored, and includes first and second master chambers and first and second pistons provided in each master chamber to pump braking fluid according to the pedal force of the brake pedal. Discharging master cylinder; A hydraulic pressure supply device that operates by electrical signals to generate hydraulic pressure; The hydraulic pressure discharged from the hydraulic pressure supply device is transmitted to wheel cylinders provided on each wheel, and includes a first hydraulic circuit including a passage connected to two wheel cylinders and a passage connected to two other wheel cylinders. A hydraulic control unit having two hydraulic circuits; First to fourth inlet valves installed on the upstream side of each wheel cylinder to selectively open and close the flow path; a first backup passage connecting the first master chamber and the first hydraulic circuit; a second backup passage connecting the second master chamber and the second hydraulic circuit; a first cut valve that selectively opens and closes the first backup passage; and a second cut valve that selectively opens and closes the second backup passage, and during normal braking, the wheel cylinder controlled by the first inlet valve and the wheel cylinder controlled by the fourth inlet valve are connected to the master. Braking pressure is formed by the hydraulic pressure formed in the cylinder, and the wheel cylinder controlled by the second inlet valve and the wheel cylinder controlled by the third inlet valve have braking pressure formed by the hydraulic pressure formed in the hydraulic pressure supply device. An electronic braking system may be provided.

In addition, the first hydraulic circuit connects a first branch passage in which the first inlet valve is installed, a second branch passage in which the second inlet valve is installed, and the first branch passage and the second branch passage. It includes a first circuit passage, and the second hydraulic circuit includes a third branch passage in which the third inlet valve is installed, a fourth branch passage in which the fourth inlet valve is installed, the third branch passage and the first branch passage. It may include a second circuit flow path connecting the fourth branch flow path.

In addition, it may further include a third cut valve installed in the first circuit flow path to control the flow of braking fluid, and a fourth cut valve installed in the second circuit flow path to control the flow of braking fluid.

Additionally, the third and fourth cut valves may be normally open type valves that are normally open and operate to close when a closing signal is received.

In addition, it may further include an electronic control unit that controls the operation of the first to fourth cut valves and the first to fourth inlet valves.

In addition, during abnormal braking, the third and fourth cut valves and the first to fourth inlet valves are opened, and the wheel cylinder controlled by each of the first to fourth inlet valves is operated by hydraulic pressure formed in the master cylinder. Braking pressure may be formed.

Additionally, when braking in one or more of the ABS mode, TCS mode, and ESC mode, the third to fourth cut valves are opened, and the first to fourth inlet valves can be controlled independently.

Embodiments of the present invention are provided so that during basic braking, some of the plurality of wheel cylinders generate braking force by transmitting the hydraulic pressure of the master cylinder, and only some of the plurality of wheel cylinders generate braking force by transmitting the hydraulic pressure of the hydraulic pressure supply device. This makes it possible to use a small actuator by reducing the amount of liquid required for the hydraulic pressure supply device.

Additionally, the hydraulic pressure from the master cylinder is directly transmitted to the wheel cylinder, providing a pedal feel to the driver without a pedal simulator.

In addition, the rear wheels of the vehicle are connected to the master cylinder and can be braked by the driver's pedal force, and the front wheels of the vehicle are connected to the hydraulic pressure supply device and can be braked using the driving force of the motor.

Additionally, in fallback mode, the hydraulic pressure of the master cylinder can be transmitted to all wheel cylinders.

1 is a hydraulic circuit diagram showing a non-braking state of an electronic brake system according to an embodiment of the present invention.
Figure 2 is an enlarged view showing a master cylinder according to an embodiment of the present invention.
Figure 3 is an enlarged view showing a hydraulic pressure providing unit according to an embodiment of the present invention.
Figure 4 is a hydraulic circuit diagram showing a normal operating state of the electronic brake system according to an embodiment of the present invention.
Figure 5 is a hydraulic circuit diagram showing a state in which the electronic brake system according to an embodiment of the present invention is operating abnormally.
Figure 6 is a hydraulic circuit diagram showing a state in which the electronic brake system according to an embodiment of the present invention is operated in ABS mode.

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 idea of the present invention to those skilled in the art. The present invention is not limited to the embodiments presented herein and may be embodied in other forms. In order to clarify the present invention, the drawings may omit illustrations of parts unrelated to the description and may slightly exaggerate the sizes of components to aid understanding.

Figure 1 is a hydraulic circuit diagram showing a non-braking state of the electronic 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 that generates hydraulic pressure and a reservoir 30 that is coupled to the upper part of the master cylinder 20 to store braking fluid, for example, oil. ), an input rod 12 that pressurizes the master cylinder 20 according to the pedal force of the brake pedal 10, and a wheel cylinder ( 40) and a pedal displacement sensor 11 that detects the displacement of the brake pedal 10.

The master cylinder 20 is configured to have at least one chamber and can generate hydraulic pressure. As an example, the master cylinder 20 may include a first master chamber 20a and a second master chamber 20b.

Next, the master cylinder 20 according to an embodiment of the present invention will be described with reference to FIG. 2. Figure 2 is an enlarged view showing the master cylinder 20 according to an embodiment of the present invention.

Referring to FIG. 2, a first piston 21a connected to the input rod 12 is provided in the first master chamber 20a, and a second piston 22a is provided in the second master chamber 20b. Additionally, the first master chamber 20a communicates with the first hydraulic port 24a to allow oil to flow in and out, and the second master chamber 20b communicates with the second hydraulic port 24b to allow oil to flow in and out. For example, the first hydraulic port 24a may be connected to the first backup passage 251, and the second hydraulic port 24b may be connected to the second backup passage 252.

Meanwhile, the master cylinder 20 can ensure safety in the event of a breakdown by having two master chambers 20a and 20b. For example, one of the two master chambers 20a and 20b is connected to the right front wheel (FR) and the left rear wheel (RL) of the vehicle through the first backup passage 251, and the other master chamber The chamber 20b may be connected to the left front wheel (FL) and the right rear wheel (RR) through the second backup passage 252. In this way, by independently configuring the two master chambers 20a and 20b, it is possible to enable braking of the vehicle even when one master chamber fails.

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

In addition, a first spring 21b is provided between the first piston 21a and the second piston 22a of the master cylinder 20, and a spring 21b is provided between the second piston 22a and the end of the master cylinder 20. 2 Springs 22b may be provided. That is, the first piston 21b can be accommodated in the first master chamber 20a, and the second piston 22b can be accommodated in the second master chamber 20b.

The first spring 21b and the second spring 22b are compressed by the first piston 21a and the second piston 22a, which move as the displacement of the brake pedal 10 changes, and elastic force is stored. And when the force pushing the first piston 21a becomes smaller than the elastic force, the first and second pistons 21a and 22a are returned to their original state by using the restoring elastic force stored in the first spring 21b and the second spring 22b. You can do it.

Meanwhile, the input rod 12 that presses the first piston 21a of the master cylinder 20 may be in close contact with the first piston 21a. That is, there may be no gap between the master cylinder 20 and the input rod 12. Therefore, when the brake pedal 10 is pressed, the master cylinder 20 can be directly pressed without a pedal invalid stroke section.

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

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

In addition, the first reservoir passage 61 allows the flow of oil flowing from the reservoir 30 into the first master chamber 20a, while allowing the flow of oil flowing into the reservoir 30 from the first master chamber 20a. A blocking check valve 64 may be provided. Check valve 64 may be arranged to allow only one-way fluid flow.

Referring again to FIG. 1, the electronic brake system 1 according to an embodiment of the present invention receives the driver's intention to brake as an electrical signal from the pedal displacement sensor 11, which detects the displacement of the brake pedal 10, and mechanically Hydraulic system consisting of an operating hydraulic pressure supply device 100 and first and second hydraulic circuits that control the flow of hydraulic pressure delivered to the wheel cylinders 40 provided on two wheels (RR, RL, FR, FL), respectively. A control unit 200, a first cut valve 261 provided in the first backup passage 251 connecting the first hydraulic port 24a and the first hydraulic circuit to control the flow of hydraulic pressure, and a second hydraulic pressure A second cut valve 262 provided in the second backup passage 252 connecting the port 24b and the second hydraulic circuit to control the flow of hydraulic pressure, and a hydraulic pressure supply device 100 based on hydraulic pressure information and pedal displacement information ) and an electronic control unit (ECU, not shown) that controls the valves (221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243, 261, 262, 263, 264) It can be included.

The hydraulic pressure supply device 100 includes a hydraulic pressure providing unit 110 that provides oil pressure transmitted to the wheel cylinder 40, a motor 120 that generates rotational force by an electrical signal from the pedal displacement sensor 11, and a motor. It may include a power conversion unit 130 that converts the rotational motion of 120 into linear motion and transmits it to the hydraulic pressure providing unit 110. Alternatively, the hydraulic pressure providing unit 110 may operate not by the driving force supplied by the motor 120 but by the pressure provided by the high pressure accumulator.

Next, the hydraulic pressure providing unit 110 according to an embodiment of the present invention will be described with reference to FIG. 3. Figure 3 is an enlarged view showing the 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 in which oil is supplied and stored is formed, a hydraulic piston 114 accommodated in the cylinder block 111, and a hydraulic piston 114 and a cylinder block 111. ) and a sealing member 115 (115a, 115b) provided between the sealing members 115a and 115b to seal the pressure chamber, and a drive shaft connected to the rear end of the hydraulic piston 114 and transmitting the power output from the power conversion unit 130 to the hydraulic piston 114. Includes (133).

The pressure chamber is a first pressure chamber 112 located in front of the hydraulic piston 114 (forward direction, left direction in the drawing), and a first pressure chamber 112 located in the rear of the hydraulic piston 114 (reverse direction, right direction in the drawing). It 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 is provided so that its volume varies depending on 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 that the volume varies depending on the movement of the hydraulic piston 114.

The first pressure chamber 112 is connected to the first hydraulic passage 211 through a first communication hole 111a formed on the rear side of the cylinder block 111, and is formed on the front side of the cylinder block 111. It is connected to the fourth hydraulic passage 214 through the second communication hole 111b. The first hydraulic passage 211 connects the first pressure chamber 112 and the first and second hydraulic circuits. And the first hydraulic passage 211 branches into a second hydraulic passage 212 in communication with the first hydraulic circuit and a third hydraulic passage 213 in communication with the second hydraulic circuit. The fourth hydraulic oil path 214 connects the second pressure chamber 113 and the first and second hydraulic circuits. And the fourth hydraulic passage 214 branches into a fifth hydraulic passage 215 in communication with the first hydraulic circuit and a sixth hydraulic passage 216 in communication with the second hydraulic circuit.

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 drive shaft sealing member 115b provided between the cylinder block 111 and sealing the opening of the second pressure chamber 113 and the cylinder block 111. That is, the hydraulic pressure or negative pressure in the first pressure chamber 112 generated by the forward or backward movement of the hydraulic piston 114 is blocked by the piston sealing member 115a and does not leak into the second pressure chamber 113, and the first pressure chamber 112 does not leak into the second pressure chamber 113. And it can be transmitted to the fourth hydraulic oil path (211, 214). In addition, the hydraulic pressure or negative pressure in the second pressure chamber 113 generated by the forward or backward movement of the hydraulic piston 114 is blocked by the drive shaft sealing member 115b and may not leak into the cylinder block 111.

The first and second pressure chambers 112 and 113 are connected to the reservoir 30 by dump passages 116 and 117, respectively, and receive oil from the reservoir 30 and store it or store it in the first or second pressure chamber ( The oil of 112, 113) can be delivered to the reservoir (30). As an example, the dump passages 116 and 117 are branched from the first pressure chamber 112 and connected to the reservoir 30, and the first dump passage 116 is branched from the second pressure chamber 113 and connected to the reservoir 30. ) may include a second dump passage 117 connected to the.

In addition, the first pressure chamber 112 is connected to the first dump passage 116 through the fifth communication hole 111f formed on the front side, and the second pressure chamber 113 is connected to the sixth dump passage 116 formed on the rear side. It can be connected to the second dump passage 117 through the communication hole 111e.

In addition, a first communication hole 111a is formed in front of the first pressure chamber 112 and communicates with the first hydraulic passage 211, and at the rear of the first pressure chamber 112, a fourth hydraulic passage 214 and A second communicating hole 111b may be formed. In addition, a third communication hole 111c communicating with the first dump passage 116 may be further formed in the first pressure chamber 112.

In addition, a third communication hole (111c) communicating with the third hydraulic passage 213 and a fourth communication hole (111d) communicating with the second dump passage 117 may be formed in the second pressure chamber 113. there is.

Referring again to FIG. 1, the flow paths 211, 212, 213, 214, 215, 216, 217, 218 and valves 231 connected to the first pressure chamber 112 and the second pressure chamber 113. 232, 233, 234, 235, 236, 241, 242, 243) will be explained.

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

As an example, the first hydraulic circuit is branched from the second hydraulic passage 212 and connected to the wheel cylinder 40 installed on the left rear wheel (RL), and the first branch passage is branched from the second hydraulic passage 212 and connected to the right side. It may include a second branch passage connected to the wheel cylinder 40 installed on the front wheel (FR).

In addition, the electronic brake system 1 according to an embodiment of the present invention includes a first control valve 231 and a second control valve (231) provided in the second and third hydraulic passages 212 and 213, respectively, to control the flow of oil. 232) may be included.

And the first and second control valves 231 and 232 only allow oil flow in the direction from the first pressure chamber 112 to the first or second hydraulic circuit 201 and 202, and allow oil flow in the opposite direction. can be provided with a blocking check valve. 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 maintaining the first or second hydraulic pressure. 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 passage 214 may branch into the fifth hydraulic passage 215 and the sixth hydraulic passage 216 and communicate with both the first hydraulic circuit and the second hydraulic circuit. For example, the fifth hydraulic passage 215 branched from the fourth hydraulic passage 214 is in communication with the first hydraulic circuit, and the sixth hydraulic passage 216 branched from the fourth hydraulic passage 214 is connected to the second hydraulic passage. It may be connected to the circuit. Accordingly, hydraulic pressure can be transmitted to both the first hydraulic circuit and the second hydraulic circuit by the backward movement of the hydraulic piston 114.

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

The third control valve 233 may be provided as a check valve that only allows oil flow in the direction from the second pressure chamber 113 to the first hydraulic circuit and blocks oil flow in the opposite direction. That is, the third control valve 233 can prevent the hydraulic pressure of the first hydraulic circuit from leaking into the second pressure chamber 113 through the fourth hydraulic passage 214.

And the fourth control valve 234 may be provided as a two-way control valve that controls the oil flow between the second pressure chamber 113 and the second hydraulic circuit. Additionally, the fourth control valve 234 may be a normally closed solenoid valve that is normally closed and opens when an opening signal is received from the electronic control unit.

In addition, the electronic brake system 1 according to an embodiment of the present invention is provided in the seventh hydraulic passage 217 connecting the second hydraulic passage 212 and the third hydraulic passage 213 and controls the flow of oil. 5 Control valve 235, and a sixth control valve 236 provided in the eighth hydraulic passage 218 connecting the second hydraulic passage 212 and the seventh hydraulic passage 217 to control the flow of oil. can do. In addition, the fifth control valve 235 and the sixth control valve 236 are normally closed and can be provided as normally closed type solenoid valves that open when an opening signal is received from the electronic control unit. there is.

The fifth control valve 235 and the sixth control valve 236 operate to open when an abnormality occurs in the first control valve 231 or the second control valve 232, thereby reducing the pressure of the first pressure chamber 112. Hydraulic pressure can be transmitted to both the first hydraulic circuit and the second hydraulic circuit.

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 extracted 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 that allow only one-way oil flow.

In addition, the electronic brake system 1 according to an embodiment of the present invention is provided in the first and second dump passages 116 and 117, respectively, and includes a first dump valve 241 and a second dump valve (241) that control the flow of oil. 242) may be further included. The dump valves 241 and 242 may be check valves that open only the direction from the reservoir 30 to the first or second pressure chambers 112 and 113 and close the direction 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 oil from flowing 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 does not allow oil to flow from the second pressure chamber 113 to the reservoir 30. It could be a check valve that blocks the flow.

In addition, the second dump passage 117 may include a bypass passage, and the bypass passage has a third dump valve 243 that controls 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 two-way flow, and is a normally open type that is open in a normal state and operates to close the valve when it receives a closing signal from the electronic control unit. type) solenoid valve.

The hydraulic pressure providing unit 110 of the electronic brake system 1 according to an embodiment of the present invention may operate in a double-acting manner. That is, as the hydraulic piston 114 advances, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the first hydraulic circuit through the first hydraulic passage 211 and the second hydraulic passage 212 and is transmitted to the left rear wheel (LR). ) and the wheel cylinder 40 installed on the right front wheel (FR) can be actuated, and is transmitted to the second hydraulic circuit through the first hydraulic passage 211 and the third hydraulic passage 213 to the left front wheel (FL) and the wheel cylinder 40 installed on the right rear wheel (RR) can be actuated.

Likewise, as the hydraulic piston 114 moves backward, the hydraulic pressure generated in the second pressure chamber 113 is transmitted to the first hydraulic circuit through the fourth hydraulic passage 214 and the fifth hydraulic passage 215 to the left rear wheel (LR). ) and the wheel cylinder 40 installed on the right front wheel (FR) can be actuated, and is transmitted to the second hydraulic circuit through the fourth hydraulic passage 214 and the sixth hydraulic passage 216 to the left front wheel (FL) and the wheel cylinder 40 installed on the right rear wheel (RR) can be actuated.

In addition, as the hydraulic piston 114 moves backward, the negative pressure generated in the first pressure chamber 112 sucks oil from the wheel cylinder 40 installed on the left rear wheel (LR) and right front wheel (FR) to form the first hydraulic circuit. , can be delivered to the first pressure chamber 112 through the second hydraulic passage 212, and the first hydraulic passage 211, and the wheel cylinder 40 is installed on the left front wheel (FL) and the right rear wheel (RR). ) can be sucked in and delivered to the first pressure chamber 112 through the second hydraulic circuit, the third hydraulic oil passage 213, and the first hydraulic oil 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 that generates rotational force by a signal output from an electronic control unit (ECU, not shown), and can generate rotational force in the forward or reverse direction. The rotation angular speed and rotation angle of the motor 120 can be precisely controlled. Since this motor 120 is already a widely known technology, detailed description will be omitted.

Meanwhile, the electronic control unit includes a motor 120 and valves 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235 provided in the electronic brake system 1 of the present invention, which will be described later. 236, 243, 261, 262, 263, 264). The operation of controlling a plurality of valves 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 as the hydraulic piston 114 slides within the pressure chamber is supplied to the first and second hydraulic oils. It is transmitted to the wheel cylinder 40 installed on 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 be composed of, for example, a worm shaft 131, a worm wheel 132, and a drive shaft 133.

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

To explain the above operations again, as displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to the electronic control unit (ECU, not shown), and the electronic control unit controls 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 through 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 on the brake pedal 10 is removed, 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 the hydraulic piston 114 connected to the drive shaft 133 returns (moves backward), generating negative pressure in the first pressure chamber 112.

Meanwhile, the generation of hydraulic pressure and negative pressure is also possible in the opposite direction. That is, as displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to the electronic control unit (ECU, not shown), and the electronic control unit drives the motor 120 in the opposite direction. to rotate the worm shaft (131) in the opposite direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 through 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 on the brake pedal 10 is removed, 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 the hydraulic piston 114 connected to the drive shaft 133 returns (moves forward), generating negative pressure in the second pressure chamber 113.

In this way, the hydraulic pressure supply device 100 transmits hydraulic pressure to the wheel cylinder 40 or suctions hydraulic pressure and transfers it to the reservoir 30 according to the rotation direction of the rotational force generated from the motor 120.

Meanwhile, 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. Should braking be performed using hydraulic pressure or negative pressure? Whether to release the braking can be determined by controlling the valves 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243, 263, and 264. This will be explained in detail later.

Although not shown in the drawing, the power conversion unit 130 may be composed of a ball screw and nut assembly. For example, it consists of a screw that is integrally formed with the rotation axis of the motor 120 or connected to rotate with the rotation axis of the motor 120, and a ball nut that is screwed to the screw in a limited rotation state and moves linearly according to the rotation of the screw. It can be. The hydraulic piston 114 is connected to the ball nut of the power conversion unit 130 and pressurizes the pressure chamber by the linear movement of the ball nut. Since the structure of the ball screw nut assembly is a device that converts rotational motion into linear motion and is a well-known technology, detailed description will be omitted.

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

In addition, the electronic brake system 1 according to an embodiment of the present invention has first and second backup passages 251 that can directly supply oil discharged from the master cylinder 20 to the wheel cylinder 40 when operating abnormally. , 252) may be further included. The mode in which the hydraulic pressure of the master cylinder 20 is directly transmitted to the wheel cylinder 40 is called fallback mode.

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 may be provided for controlling the flow of oil 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, and the second backup passage 252 connects the second hydraulic port 24b and the second hydraulic circuit. .

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

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

The hydraulic control unit 200 may be composed of a first hydraulic circuit and a second hydraulic circuit that receive hydraulic pressure and control two wheels, respectively. For example, the first hydraulic circuit can control the left rear wheel (RL) and the right front wheel (FR), and the second hydraulic circuit can control the right rear wheel (RR) and the left front wheel (FL). And a wheel cylinder 40 is installed on each wheel (FR, FL, RR, RL) to receive hydraulic pressure and perform braking.

The first hydraulic circuit is connected to the second hydraulic passage 212 through the first hydraulic passage 211 and receives hydraulic pressure from the hydraulic supply device 100, and the second hydraulic passage 212 is connected to the right front wheel (FR) and It branches into two channels leading to the left rear wheel (RL).

Likewise, the second hydraulic circuit is connected to the third hydraulic passage 213 through the first hydraulic passage 211 and receives hydraulic pressure from the hydraulic supply device 100, and the third hydraulic passage 213 is connected to the left front wheel (FL). ) and branches into two channels connected to the right rear wheel (RR).

And the first hydraulic circuit may include a first circuit passage 253 that communicates the first branch passage and the second branch passage. And the first hydraulic circuit may further include a third cut valve 263 that selectively opens and closes the first circuit passage 253.

And the second hydraulic circuit branches off from the third hydraulic passage 213 and connects to the wheel cylinder 40 installed on the left front wheel (FL) and the third hydraulic passage 213 branches off from the right rear wheel (FL). It may include a fourth branch passage connected to the wheel cylinder 40 installed in RR).

And the second hydraulic circuit may include a second circuit flow path 254 that communicates the third branch flow path and the fourth branch flow path. And the second hydraulic circuit may further include a fourth cut valve 264 that selectively opens and closes the second circuit flow passage 254.

In addition, the third and fourth cut valves 263 and 264 may be provided as solenoid valves capable of controlling two-way flow, and are open in normal conditions and operate to close when a closing signal is received from the electronic control unit. It can be provided as a normally open type solenoid valve.

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

For example, first to fourth inlet valves 221a, 221b, 221c, and 221d may be installed in the first to fourth branch passages, respectively.

In addition, the inlet valve 221 is located on the upstream side of the wheel cylinder 40 and is a normally open type solenoid valve that is open in a normal state and operates to close the valve when it receives a closing signal from the electronic control unit. It can be prepared by.

In addition, the hydraulic circuits 201 and 202 may include check valves 223a, 223b, 223c, and 223d provided in the bypass passage connecting the front and rear of each inlet valve 221a, 221b, 221c, and 221d. You can. The check valves (223a, 223b, 223c, and 223d) only allow oil to flow from the wheel cylinder 40 to the hydraulic pressure providing unit 110, and oil flows from the hydraulic pressure providing unit 110 to the wheel cylinder 40. Arrangements may be made to limit the flow of The check valves (223a, 223b, 223c, 223d) can quickly release the braking pressure of the wheel cylinder 40, and if the inlet valves (221a, 221b, 221c, 221d) do not operate normally, the wheel cylinder The hydraulic pressure of (40) can be allowed to flow 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 each wheel cylinder 40 and controls the escape of hydraulic pressure from each wheel (RR, RL, FR, FL). That is, the outlet valve 222 detects the braking pressure of each wheel (RR, RL, FR, FL) and is selectively opened to control the pressure when decompression braking is necessary.

For example, first to fourth outlet valves 222a, 222b, 222c, and 222d may be installed in the first to fourth branch passages, respectively.

Additionally, the outlet valve 222 may be a normally closed solenoid valve that is normally closed and opens when an opening signal is received from the electronic control unit.

Additionally, the hydraulic control unit 200 may be connected to the backup passages 251 and 252. As an example, the first hydraulic circuit is connected to the first backup passage 251 and receives hydraulic pressure from the master cylinder 20, and the second hydraulic circuit is connected to the second backup passage 252 to receive hydraulic pressure from the master cylinder 20. Hydraulic pressure can be provided.

The first backup passage 251 may join the first hydraulic circuit upstream of the first and second inlet valves 221a and 221b. For example, the first backup passage 251 may be directly connected to the first branch passage and connected to the second branch passage through the first circuit passage 253.

Likewise, the second backup passage 252 may join the second hydraulic circuit upstream of the third and fourth inlet valves 221c and 221d. For example, the second backup passage 252 may be directly connected to the fourth branch passage and may be connected to the third branch passage through the second circuit passage 254.

Therefore, when the first and second cut valves 261 and 262 are closed, the hydraulic pressure provided from the hydraulic pressure supply device 100 can be supplied to the wheel cylinder 40 through the first and second hydraulic circuits, and the first and second cut valves 261 and 262 can be closed. When the second cut valves 261 and 262 are opened, the hydraulic pressure provided from the master cylinder 20 can be supplied to the wheel cylinder 40 through the first and second backup passages 251 and 252. At this time, since the plurality of inlet valves 221a, 221b, 221c, and 221d are in an open state, there is no need to change their operating states.

Meanwhile, the unexplained reference number “PS1” is a hydraulic oil pressure sensor that detects the hydraulic pressure of the hydraulic circuits 201 and 202. Although the drawing shows that the hydraulic oil pressure sensor PS1 is installed in the second hydraulic circuit, unlike this, it is installed in the first hydraulic circuit.

And “PS2” is a backup oil pressure sensor that measures the oil pressure of the master cylinder (20). In the drawing, the backup passage pressure sensor (PS2) is shown to be installed in the first backup passage 251, but unlike this, it is installed in the second backup passage 252.

And “MPS” is a motor control sensor that controls the rotation angle of the motor 120 or the current of the motor.

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

Figure 4 is a hydraulic circuit diagram showing a normal operating state of the electronic brake system 1 according to an embodiment of the present invention.

Referring to FIG. 4, when the hydraulic pressure supply device 100 operates normally, the wheel cylinder 40 provided at the front wheels (FR, FL) has braking pressure generated by the hydraulic pressure supply device 100 (boosting, boosting), the wheel cylinder 40 provided at the rear wheels (RL, RR) generates braking pressure by transmitting the braking force provided by the driver by pressing the brake pedal 10 through the master cylinder 20 (push- Through, Push-through).

Specifically, when the driver steps on the brake pedal 10, the input rod 12 connected to the brake pedal 10 moves forward, and at the same time, the first piston 21a in contact with the input rod 12 moves forward, and the first piston 21a moves forward. The second piston 22a also moves forward due to pressure or movement of the piston 21a. At this time, braking can be performed quickly because there is no gap between the input rod 12 and the first piston 21a.

And the hydraulic pressure discharged from the first master chamber (20a) is transmitted to the wheel cylinder 40 provided on the left rear wheel (RL) through the first backup passage 251, and the hydraulic pressure discharged from the second master chamber (20b) is transmitted to the wheel cylinder 40 provided on the right rear wheel (RR) through the second backup passage 252 to generate braking force. That is, the hydraulic pressure discharged from the master cylinder 20 generates braking force in the wheel cylinders 40 provided at the rear wheels RL and RR.

At this time, the third cut valve 263 and the fourth cut valve 264 may be switched to a closed state. Therefore, the hydraulic pressure discharged from the master cylinder 20 does not flow into the second and third branch passages.

Specifically, the hydraulic pressure provided from the first master chamber 20a is a wheel cylinder provided on the left rear wheel RL through the first backup passage 251 and the first branch passage connected to the first hydraulic port 24a ( 40) is delivered directly. At this time, the first inlet valve 221a installed in the first branch flow path is provided in an open state. Additionally, the first outlet valve 222a installed in the flow path branching from the first branch flow path is maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30.

And the hydraulic pressure provided from the second master chamber 20b is connected to the second hydraulic port 24b and the wheel cylinder 40 provided on the right rear wheel (RR) through the second backup passage 252 and the fourth branch passage. is delivered directly to At this time, the fourth inlet valve 221d installed in the fourth branch flow path is provided in an open state. In addition, the fourth outlet valve 222d installed in the passage branching from the fourth branch passage is maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30.

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

The hydraulic piston 114 moves forward and generates hydraulic pressure in the first pressure chamber 112. As the hydraulic piston 114 moves forward from the initial state, that is, as the stroke of the hydraulic piston 114 increases, the amount of oil delivered from the first pressure chamber 112 to the wheel cylinder 40 increases and the braking pressure increases. rises However, since there is an effective stroke of the hydraulic piston 114, there is a maximum pressure due to the forward movement of the hydraulic piston 114.

At this time, the maximum pressure in low pressure mode is smaller than the maximum pressure in 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 of the first pressure chamber 112 flows into the wheel cylinder 40, but some of it flows into the second pressure chamber 113.

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

When braking by the driver begins, the amount of braking required by the driver can be detected through information such as the pressure of the brake pedal 10 pressed by the driver through the pedal displacement sensor 11. The electronic control unit (not shown) receives the electrical signal output from the pedal displacement sensor 11 and drives the motor 120.

In addition, the electronic control unit receives the size of the regenerative braking amount through the backup passage pressure sensor (PS2) provided on the outlet side of the master cylinder 20 and the hydraulic passage pressure sensor (PS1) provided in the second hydraulic circuit, and receives the driver's By calculating the size of the friction braking amount according to the difference between the required braking amount and the regenerative braking amount, the amount of pressure increase or decrease in the wheel cylinder 40 can be determined.

When the driver steps on the brake pedal 10 at the beginning of braking, the motor 120 operates to rotate in one direction, and the rotational force of this motor 120 is transmitted to the hydraulic pressure providing unit 110 by the power transmission unit 130. , the hydraulic piston 114 of the hydraulic pressure providing unit 110 advances and generates hydraulic pressure in the first pressure chamber 112. The hydraulic pressure discharged from the hydraulic pressure providing unit 110 is transmitted to the wheel cylinder 40 provided at the right front wheel (FR) through the second branch passage, and the wheel cylinder provided at the left front wheel (FL) through the third branch passage. It is transmitted to (40) to generate braking force. That is, the hydraulic pressure discharged from the hydraulic pressure providing unit 110 generates braking force in the wheel cylinders 40 provided at the front wheels FR and FL.

At this time, the third cut valve 263 and the fourth cut valve 264 may be switched to a closed state. Therefore, the hydraulic pressure discharged from the hydraulic pressure providing unit 110 does not flow into the first and fourth branch passages.

Specifically, the hydraulic pressure provided from the first pressure chamber 112 is supplied to the right front wheel ( It is directly transmitted to the wheel cylinder 40 provided in FR). At this time, the second inlet valve 221b installed in the second branch flow path is provided in an open state. Additionally, the second outlet valve 222b installed in the flow path branching from the second branch flow path is maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30.

And the hydraulic pressure provided from the first pressure chamber 112 is supplied to the left front wheel (FL) through the first hydraulic passage 211, the third hydraulic passage 213, and the third branch passage connected to the first communication hole 111a. It is directly transmitted to the wheel cylinder 40 provided in. At this time, the third inlet valve 221c installed in the third branch flow path is provided in an open state. Additionally, the third outlet valve 222c installed in the flow path branching from the third branch flow path is maintained in a closed state to prevent hydraulic pressure from leaking into the reservoir 30.

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

And the fourth control valve 234 can be maintained in a closed state to block the sixth hydraulic passage 216. The pressure increase rate per stroke can be improved by preventing the hydraulic pressure generated in the first pressure chamber 112 from being transmitted to the second pressure chamber 113 through the sixth hydraulic passage 216 connected to the second hydraulic passage 212. there is. Therefore, a rapid 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 force of the brake pedal 10, any one or more of the second or third outlet valves 222b and 222c are opened to reach the target pressure. It can be controlled to follow the pressure value.

In addition, the hydraulic passage pressure sensor PS1 installed in the third hydraulic passage 213 is connected to the wheel cylinder 40 (hereinafter simply referred to as the wheel cylinder 40) installed on the left front wheel (FL) or right rear wheel (RR). The flow rate transmitted can be detected. Therefore, the flow rate delivered to the wheel cylinder 40 can be controlled by controlling the hydraulic pressure supply device 100 according to the output of the hydraulic oil pressure sensor PS1. Specifically, the flow rate and discharge speed discharged from the wheel cylinder 40 can be controlled by adjusting the forward distance and forward speed of the hydraulic piston 114.

Meanwhile, the low-pressure mode may be switched to the high-pressure mode before the hydraulic piston 114 moves forward to its maximum.

In the high pressure mode, the fourth control valve 234 is switched to the open state to open the sixth hydraulic passage 216. Therefore, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the second pressure chamber 113 through the sixth hydraulic passage 216 connected to the second hydraulic passage 212 to push the hydraulic piston 114. can be used

In the high pressure mode, a portion of the oil pushed out of the first pressure chamber 112 flows into the second pressure chamber 113, so the pressure increase rate per stroke decreases. However, because 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 why 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.

Additionally, the hydraulic pressure supply device 100 according to an embodiment of the present invention can provide braking pressure while the hydraulic piston 114 moves backward.

When the driver steps on the brake pedal 10 at the beginning of braking, the motor 120 operates to rotate in the opposite direction, and the rotational force of this motor 120 is transmitted to the hydraulic pressure providing unit 110 by the power transmission unit 130. , the hydraulic piston 114 of the hydraulic pressure providing unit 110 moves backwards and generates hydraulic pressure in the second pressure chamber 113.

Specifically, the hydraulic pressure provided from the second pressure chamber 113 is supplied to the right front wheel ( It is directly transmitted to the wheel cylinder 40 provided in FR).

And the hydraulic pressure provided from the second pressure chamber 113 is supplied to the left front wheel (FL) through the fourth hydraulic passage 214, the sixth hydraulic passage 216, and the third branch passage connected to the second communication hole 111b. It is directly transmitted to the wheel cylinder 40 provided in.

And the fourth control valve 234 is switched to the open state to open the sixth hydraulic passage 216. Meanwhile, the third control valve 233 is provided as a check valve that allows hydraulic pressure to be transmitted from the second pressure chamber 113 toward the wheel cylinder 40, so the fifth hydraulic passage 215 is opened.

And the sixth control valve 236 can be maintained in a closed state to block the eighth hydraulic passage 218. The pressure increase rate per stroke can be improved 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. there is. Therefore, a rapid braking response can be expected at the beginning of braking.

Next, we will look at a case where the braking force is released in a braked state during normal operation of the electronic brake system 1 according to an embodiment of the present invention.

When the hydraulic pressure supply device 100, etc. operates normally, when the driver releases the brake pedal 10, the negative pressure formed in the first master chamber 20a is supplied to the left rear wheel RL through the first backup passage 251. The hydraulic pressure of the wheel cylinder 40 provided is removed, and the negative pressure formed in the second master chamber 20b is supplied to the wheel cylinder 40 provided at the right rear wheel RR through the second backup passage 252. Remove it to release the braking force. That is, the negative pressure formed in the master cylinder 20 releases the braking force on the wheel cylinders 40 provided at the rear wheels RL and RR.

At this time, the third cut valve 263 and the fourth cut valve 264 may be switched to a closed state. Therefore, the negative pressure formed in the master cylinder 20 is not transmitted to the second branch passage and the third branch passage.

In addition, when the pedal force applied to the brake pedal 10 is released, the motor 120 generates a rotational force in the opposite direction to that during braking and transmits it to the power conversion unit 130, and the worm shaft 131 of the power conversion unit 130 , the worm wheel 132, and the drive shaft 133 rotate in the opposite direction to that 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. And the hydraulic pressure providing unit 110 receives the hydraulic pressure discharged from the wheel cylinders 40 provided on the right front wheel (FR) and the left front wheel (FL) through the first and second hydraulic circuits and supplies them to the first pressure chamber 112. It will be delivered to .

Specifically, the negative pressure generated in the first pressure chamber 112 is connected to the first communication hole 111a through the first hydraulic passage 211, the second hydraulic passage 212, and the second branch passage. Release the pressure of the wheel cylinder 40 provided in FR). At this time, the second inlet valve 221b installed in the second branch passage branching from the second hydraulic passage 212 is provided in an open state. Additionally, the second outlet valve 222b installed in the flow path branching from the second branch flow path is maintained in a closed state to prevent oil from flowing into the reservoir 30.

And the negative pressure generated in the first pressure chamber 112 is connected to the first communication hole 111a through the first hydraulic passage 211, the third hydraulic passage 213, and the third branch passage to the left front wheel (FL). Release the pressure of the wheel cylinder 40 provided in. At this time, the third inlet valve 221c installed in the third branch passage branching from the third hydraulic passage 213 is provided in an open state. Additionally, the third outlet valve 222c installed in the flow path branching from the third branch flow path is maintained in a closed state to prevent oil from flowing into the reservoir 30.

And the fourth control valve 234 is switched to the open state to open the sixth hydraulic passage 216, and the fifth control valve 235 is switched to the open state to open the seventh hydraulic passage 217. 6 The control valve 236 can be switched to the open state to open the eighth hydraulic oil passage 218. As the sixth hydraulic passage 216, the seventh hydraulic passage 217, and the eighth hydraulic passage 218 communicate with each other, the first pressure chamber 112 and the second pressure chamber 113 communicate with each other.

In order for negative pressure to be formed in the first pressure chamber 112, the hydraulic piston 114 must move backwards, but if the second pressure chamber 113 is full of oil, resistance occurs in the hydraulic piston 114 moving backwards. At this time, the fourth control valve 234, the fifth control valve 235, and the sixth control valve 236 are opened so that the fourth hydraulic passage 214 and the sixth hydraulic passage 216 are connected to the second hydraulic passage ( 212) and the first hydraulic oil path 211, the oil in the second pressure chamber 113 moves to the first pressure chamber 112.

And the third dump valve 243 can be switched to a closed state. When the third dump valve 243 is closed, 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 may be kept open and oil in the second pressure chamber 113 may flow into the reservoir 30.

In addition, when the negative pressure transmitted to the first and second hydraulic circuits is measured to be higher than the target pressure release value according to the release amount of the brake pedal 10, any one or more of the first to fourth outlet valves 222 are opened. It can be controlled to follow the target pressure value.

Meanwhile, in the high pressure mode, the oil in the second pressure chamber 113 along with the oil in the wheel cylinder 40 is transferred to the first pressure chamber (113) due to the negative pressure in the first pressure chamber 112 generated as the hydraulic piston 114 moves backwards. 112), the pressure reduction rate of the wheel cylinder 40 is small. Therefore, rapid pressure release may be difficult in high pressure mode.

For this reason, high pressure mode can only be used in high pressure situations, and can be switched to low pressure mode when the pressure falls below a certain level.

Meanwhile, in the low pressure mode, the fourth control valve 234 is maintained or switched in a closed state, and instead of closing the sixth hydraulic passage 216, the third dump valve 243 is switched or maintained in an open state to open the second pressure chamber. (113) can be connected to the reservoir (30).

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

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

Additionally, the hydraulic pressure supply device 100 according to an embodiment of the present invention can release braking pressure as the hydraulic piston advances.

In addition, when the pedal force applied to the brake pedal 10 is released, the motor 120 generates a rotational force in the opposite direction to that during braking and transmits it to the power conversion unit 130, and the worm shaft 131 of the power conversion unit 130 , the worm wheel 132, and the drive shaft 133 rotate in the opposite direction during braking to advance the hydraulic piston 114 to its original position, thereby releasing the pressure in the second pressure chamber 113 or generating negative pressure. And the hydraulic pressure providing unit 110 receives the hydraulic pressure discharged from the wheel cylinders 40 provided at the right front wheel (FR) and left front wheel (FL) through the first and second hydraulic circuits and supplies them to the second pressure chamber 113. It will be delivered to .

Specifically, the negative pressure generated in the second pressure chamber 113 is transmitted to the right front wheel ( Release the pressure of the wheel cylinder 40 provided in FR). At this time, the second inlet valve 221b installed in the second branch passage branching from the second hydraulic passage 212 is provided in an open state. Additionally, the second outlet valve 222b installed in the flow path branching from the second branch flow path is maintained in a closed state to prevent oil from flowing into the reservoir 30.

And the negative pressure generated in the second pressure chamber 113 is connected to the fourth hydraulic passage 214, the sixth hydraulic passage 216, the seventh hydraulic passage 217, and the third branch connected to the second communication hole 111b. The pressure of the wheel cylinder 40 provided on the left front wheel (FL) is released through the flow path 213. At this time, the third inlet valve 221c installed in the third branch flow path is provided in an open state. Additionally, the third outlet valve 222c installed in the flow path branching from the third branch flow path is maintained in a closed state to prevent oil from flowing into the reservoir 30.

And the fourth control valve 234 is switched to the open state to open the sixth hydraulic passage 216, and the fifth control valve 235 is changed to the open state to open the seventh hydraulic passage 217. .

In addition, when the negative pressure transmitted to the first and second hydraulic circuits is measured to be higher than the target pressure release value according to the release amount of the brake pedal 10, any one or more of the first to fourth outlet valves 222 are opened. It can be controlled to follow the target pressure value.

Additionally, the hydraulic channel pressure sensor PS1 installed in the third hydraulic channel 213 can detect the flow rate discharged from the wheel cylinder 40 installed on the left front wheel (FL) or 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 according to the output of the hydraulic oil pressure sensor PS1. Specifically, the flow rate and discharge speed discharged from the wheel cylinder 40 can be controlled by adjusting the forward distance and forward speed of the hydraulic piston 114.

Next, we will explain the case where the above electronic brake system (1) does not operate normally. That is, the fallback mode situation will be described.

Figure 5 is a hydraulic circuit diagram showing a state in which the electronic brake system 1 according to an embodiment of the present invention is operating abnormally.

If the electronic brake system (1) does not operate normally, each valve (221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243, 261, 262, 263, 264) It is prepared in the initial state of braking, which is in an operating state.

Referring to Figure 5, when the hydraulic pressure supply device 100, etc. does not operate normally, when the driver steps on the brake pedal 10, the input rod 12 connected to the brake pedal 10 moves forward, and at the same time, the input rod (100) moves forward. The first piston 21a in contact with 12) moves forward, and the second piston 22a also moves forward due to pressure or movement of the first piston 21a. At this time, braking can be performed quickly because there is no gap between the input rod 12 and the first piston 21a.

And the hydraulic pressure discharged from the master cylinder 20 is transmitted to the wheel cylinder 40 through the first and second backup passages 251 and 252 connected for backup braking, thereby implementing braking force.

At this time, the first and second cut valves (261, 262) installed in the first and second backup passages (251, 252), the first and second circuit passages (253, 254), and the first hydraulic circuit The inlet valve 221, which opens and closes the flow path of the second hydraulic circuit, is configured as a normally open solenoid valve, so the hydraulic pressure discharged from the master cylinder 20 is directly transmitted to the four wheel cylinders 40.

And an outlet valve 222 connecting the first hydraulic circuit and the second hydraulic circuit to the reservoir 30, a fourth control valve 234, a fifth control valve 235, and a sixth control valve 236. As it is configured as a normally closed solenoid valve, the hydraulic pressure discharged from the master cylinder 20 does not leak into the reservoir 30 or the hydraulic pressure providing unit 110.

Therefore, even in the fallback mode, stable braking can be performed by providing braking force to the four wheel cylinders 40, thereby improving braking stability.

Figure 6 is a hydraulic circuit diagram showing a state in which the electronic brake system 1 according to an embodiment of the present invention is operated in ABS mode.

Referring to FIG. 6 , a situation may arise in which the driver must supplement or remove braking pressure from one or more wheel cylinders 40 among the four wheel cylinders 40 regardless of the driver's intention to brake.

In the drawing, the state operating in ABS mode is used as an example, but this situation can also occur in TCS/ESC mode. In anti-lock brake system (ABS) mode, high pressure may be continuously supplied by the reciprocating motion of the hydraulic piston 114, which operates in a double-acting manner. For example, the first to fourth cut valves 261, 262, 263, and 264 can be alternately controlled. And in TCS (Traction control system)/ESC (Electronic stability control) mode, the pressure on one or more target wheels can be controlled.

In ABS mode, etc., the first and second cut valves 261 and 262 installed in the first and second backup passages 251 and 252 are switched to a closed state. Therefore, it is possible to prevent the hydraulic pressure generated in the hydraulic pressure supply device 100 from being transmitted to the reservoir 30 along the first and second backup passages 251 and 252.

Additionally, the third and fourth cut valves 263 and 264 installed in the first and second circuit passages 253 and 254 may be maintained in an open state. By opening the third cut valve 263, the hydraulic pressure discharged from the hydraulic pressure supply device 100 can be transmitted to the wheel cylinder 40 provided at the left rear wheel (RL), and by opening the fourth cut valve 264, The hydraulic pressure discharged from the hydraulic pressure supply device 100 may be transmitted to the wheel cylinder 40 provided at the right rear wheel (RR).

And the first to fourth inlet valves (221a, 221b, 221c, 221d) and the first to fourth outlet valves (222a, 222b, 222c, 222d) provide pressure to the target wheel cylinder 40 or wheel cylinder ( 40) can be independently controlled to eliminate pressure.

For example, when pressure needs to be provided to the wheel cylinder 40 provided on the left front wheel (FL), the third inlet valve 221c is maintained in the open state, and the first, second, and fourth inlet valves are maintained. (221a, 221b, 221d) switches to the closed state. And the first to fourth outlet valves 222a, 222b, 222c, and 222d are maintained in a closed state.

10: Brake pedal 11: Pedal displacement sensor
20: master cylinder 30: reservoir
40: wheel cylinder
100: Hydraulic pressure supply device 110: Hydraulic pressure provision unit
120: motor 130: power conversion unit
200: hydraulic control unit 201: first hydraulic circuit
202: second hydraulic circuit 211: first hydraulic oil path
212: second hydraulic oil path 213: third hydraulic oil path
214: Fourth hydraulic oil path 215: Fifth hydraulic oil path
216: 6th hydraulic oil path 217: 7th hydraulic oil path
218: 8th hydraulic oil 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: 3rd dump valve 251: 1st backup flow path
252: 2nd backup flow path 253: 1st circuit flow path
254: 2nd circuit flow path 261: 1st cut valve
262: second cut valve 263: third cut valve
264: Fourth cut valve

Claims (16)

A master cylinder connected to a reservoir storing braking fluid, having first and second master chambers and first and second pistons provided in each master chamber, and discharging braking fluid according to the pedal force of the brake pedal;
A hydraulic pressure supply device that operates by electrical signals to generate hydraulic pressure;
The hydraulic pressure discharged from the hydraulic pressure supply device is transmitted to wheel cylinders provided on each wheel, and a first hydraulic circuit includes a passage connected to some of the wheel cylinders and a second hydraulic circuit includes a passage connected to other portions of the wheel cylinders. A hydraulic control unit having a hydraulic circuit;
First to fourth inlet valves installed on the upstream side of each wheel cylinder to selectively open and close the flow path;
a first backup passage connecting the first master chamber and the first hydraulic circuit;
a second backup passage connecting the second master chamber and the second hydraulic circuit;
a first cut valve that selectively opens and closes the first backup passage; and
It includes a second cut valve that selectively opens and closes the second backup passage,
The first hydraulic circuit includes a first branch passage in which the first inlet valve is installed, a second branch passage in which the second inlet valve is installed, and a first branch passage connecting the first branch passage and the second branch passage. Includes Circuit Euro,
The second hydraulic circuit is a third branch passage in which the third inlet valve is installed, a fourth branch passage in which the fourth inlet valve is installed, and a second hydraulic circuit connecting the third branch passage and the fourth branch passage. Includes Circuit Euro,
The hydraulic pressure supply device generates hydraulic pressure using a piston operated by an electrical signal output in response to the displacement of the brake pedal, and is provided on one side of the piston movably accommodated inside the cylinder block to create one or more wheel cylinders. It includes a first pressure chamber connected to and a second pressure chamber provided on the other side of the piston and connected to one or more wheel cylinders,
A first hydraulic passage in communication with the first pressure chamber,
It further includes second and third hydraulic passages branching from the first hydraulic passage,
The second hydraulic oil path is connected to the first hydraulic circuit, and the third hydraulic oil path is connected to the second hydraulic circuit. According to paragraph 1,
The first backup passage is directly connected to the first branch passage, and the second backup passage is directly connected to the fourth branch passage. According to paragraph 2,
A third cut valve installed in the first circuit flow path to control the flow of braking fluid,
An electronic brake system further comprising a fourth cut valve installed in the second circuit flow path to control the flow of braking fluid. According to paragraph 3,
The third and fourth cut valves are normally open and operate to close when a closing signal is received. An electronic brake system that is a normally open type valve. According to paragraph 1,
Further comprising a pedal displacement sensor that outputs an electrical signal in response to displacement of the brake pedal,
The hydraulic pressure supply device is an electronic brake system operated by an electrical signal from the pedal displacement sensor. delete According to paragraph 1,
A fourth hydraulic passage communicating with the second pressure chamber,
A fifth hydraulic passage branching from the fourth hydraulic passage and joining the second hydraulic passage,
The electronic brake system further includes a sixth hydraulic passage that branches off from the fourth hydraulic passage and joins the third hydraulic passage. According to paragraph 1,
The first branch passage directly connected to the first backup passage and the fourth branch passage directly connected to the second backup passage are connected to a wheel cylinder provided on either the front wheel or the rear wheel,
The second branch passage connected to the first backup passage through the first circuit passage and the third branch passage connected to the second backup passage through the second circuit passage are provided on the other of the front wheels or the rear wheels. An electronic brake system connected to the wheel cylinder. delete delete delete delete delete delete delete delete

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