Electro-hydraulic brake

Abstract

The present invention provides an electro-hydraulic brake including a plurality of wheel brakes, a reservoir storing brake fluid, a master cylinder connected to the reservoir and configured to generate hydraulic pressure in cooperation with a first motor, an auxiliary actuator including a second motor and a pump unit having a piston pump coupled thereto and transmitting the hydraulic pressure to the wheel brakes when the master cylinder fails, a hydraulic circuit configured to selectively transmit the hydraulic pressure to the wheel brakes and including a front wheel hydraulic circuit and a rear wheel hydraulic circuit each configured to transmit the hydraulic pressure to a pair of front wheel brakes and a pair of rear wheel brakes, respectively, and a plurality of solenoid valves, a first controller controlling the first motor and the hydraulic circuit according to a brake input, and a second controller controlling the first motor and the front wheel hydraulic circuit when the first controller fails.

Description

Technical Field

[0001] This disclosure relates to an electro-hydraulic brake. Background Technology

[0002] The description in this section provides background information for this disclosure only and does not constitute prior art.

[0003] Electro-hydraulic brakes use an electric motor to generate hydraulic pressure, which is then transmitted to the wheel cylinders to produce braking force at each wheel. Electro-hydraulic brakes make it easy to individually control the braking force generated at each wheel brake, thus enabling the easy implementation of functions such as Electronic Stability Control (ESC) or Anti-lock Braking System (ABS).

[0004] ESC (Electronic Stability Control) is used to maintain vehicle stability when the vehicle's posture becomes unstable during driving. Factors that cause vehicle instability include slippery road conditions such as rain, snow, and sand, and inertia such as rapid zigzag driving. The ESC system maintains vehicle stability by controlling the brakes and engine torque when the vehicle's posture becomes dangerous.

[0005] Redundancy in the braking system is necessary to prevent hazards caused by malfunctions in the electronically operated braking system. For example, if an electronic failure occurs in the vehicle's braking system, the driver can apply braking force by pressing the pedal. Alternatively, the braking system can be configured as a dual-box system, using the other braking system to apply braking force if one system fails.

[0006] However, when the braking system is configured as a dual-box system, the physical limitation of installing two braking systems within the engine compartment further complicates the situation. Additionally, extra space and space are required to connect the two controllers via piping.

[0007] Furthermore, when an inexpensive DC motor and two piston pumps are used to dual-function the actuator, a problem arises that noise is generated due to the pulsation of the piston pumps' characteristics. Summary of the Invention

[0008] According to at least one embodiment, this disclosure provides an electro-hydraulic brake comprising: a plurality of wheel brakes configured to supply braking force to the wheels of a vehicle; a reservoir for storing brake fluid; a master cylinder connected to the reservoir and configured to cooperate with a first motor to generate hydraulic pressure; an auxiliary actuator including a second motor and a pump unit having three or more piston pumps connected to the second motor, and the auxiliary actuator being configured to transmit the hydraulic pressure to the plurality of wheel brakes in the event of a failure of the master cylinder; a hydraulic circuit configured to selectively transmit the hydraulic pressure to the plurality of wheel brakes, and including a front wheel hydraulic circuit, a rear wheel hydraulic circuit, and a plurality of solenoid valves, the front wheel hydraulic circuit being configured to transmit the hydraulic pressure to a pair of front wheel brakes, and the rear wheel hydraulic circuit being configured to transmit the hydraulic pressure to a pair of rear wheel brakes; a first controller configured to control the first motor and the hydraulic circuit according to a brake input; and a second controller configured to control the first motor and the front wheel hydraulic circuit in the event of a failure of the first controller. Attached Figure Description

[0009] Figure 1 This is a hydraulic circuit diagram of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0010] Figure 2 This is a table showing the control relationships between a first controller and a second controller of an electro-hydraulic brake according to one embodiment of the present disclosure and a plurality of solenoid valves.

[0011] Figure 3 This is a hydraulic circuit diagram showing the brake oil flow when a fault occurs in the master cylinder of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0012] Figure 4A and Figure 4B This is a graph comparing the operating noise of the piston pump of an electro-hydraulic brake according to one embodiment of the present disclosure and that of a conventional electro-hydraulic brake.

[0013] Figure 5A and Figure 5B This is a graph comparing the piston pump displacement of an electro-hydraulic brake according to one embodiment of the present disclosure and a conventional electro-hydraulic brake.

[0014] Figure 6 This is a diagram illustrating another embodiment of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0015] Figure 7This is a diagram illustrating another embodiment of an electro-hydraulic brake according to one embodiment of the present disclosure. Detailed Implementation

[0016] An electro-hydraulic brake according to one embodiment of the present disclosure can implement redundancy in the vehicle's braking system by using only a dual-design controller within a single mechanical package.

[0017] An electro-hydraulic brake according to one embodiment of the present disclosure can reduce pulsation and noise by improving the structure of the auxiliary actuator and applying and connecting an odd number of piston pumps to each circuit.

[0018] The objectives of this disclosure are not limited to those described above, and other objectives will be clearly understood by those skilled in the art based on the following description.

[0019] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, similar reference numerals preferably designate similar elements, although these elements are shown in different figures. Furthermore, in the following description of some embodiments, for the sake of clarity and brevity, detailed descriptions of related known components and functions will be omitted when they are deemed to obscure the subject matter of the present disclosure.

[0020] Furthermore, when numbering components, alphanumeric codes such as first, second, i), ii), (a), and (b) are used only to distinguish one component from another and do not imply or suggest the material, order, or sequence of the components. Throughout the specification, when a part "comprises" or "includes" a component, it means that other components are included, not excluded, unless specifically described to the contrary. Terms such as "unit" or "module" refer to one or more units for performing at least one function or operation, which may be implemented by hardware, software, or a combination thereof.

[0021] Figure 1 This is a hydraulic circuit diagram of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0022] Reference Figure 1 An electro-hydraulic brake 100 according to one embodiment of the present disclosure may include all or part of a master cylinder 110, a reservoir, a hydraulic circuit, and a controller. The controller may be an electronic control unit (ECU). The controller may include a first controller 180 and a second controller 190.

[0023] The master cylinder 110 may include all or part of the first motor 111, ball screw, piston 113, first chamber 115 and second chamber 117.

[0024] The master cylinder 110 can cooperate with the first motor 111 to generate brake fluid pressure. When the driver depresses the brake pedal, the first motor 111 rotates by means of an electrical signal, causing the ball screw and piston 113 connected to the first motor 111 to move forward, thus generating hydraulic pressure in the master cylinder. When the brake pedal is depressed, the master cylinder can supply hydraulic pressure to multiple wheel brakes w1, w2, w3, and w4. In this case, the forward movement direction refers to the piston 113 moving towards the first chamber 115, and the backward movement direction refers to the piston 113 moving towards the second chamber 117.

[0025] The master cylinder 110 may have a dual structure, internally divided into a first chamber 115 and a second chamber by the piston 113. The first motor 111 has a dual-winding structure, and assuming the performance of the first motor 111 is 100%, the first controller 180 and the second controller 190 may each control 50% of the first motor 111.

[0026] The multiple wheel brakes w1, w2, w3, and w4 include: a first wheel brake w1 that brakes the left front wheel of the vehicle; a second wheel brake w2 that brakes the right front wheel of the vehicle; a third wheel brake w3 that brakes the left rear wheel of the vehicle; and a fourth wheel brake w4 that brakes the right rear wheel of the vehicle. The first to fourth wheel brakes w1 to w4 are formally defined for ease of description, and their positions are not limited to those defined above.

[0027] The hydraulic circuit of the electro-hydraulic brake 100 may include a front wheel hydraulic circuit and a rear wheel hydraulic circuit. The front wheel hydraulic circuit may be configured to transmit hydraulic pressure to a pair of front wheel brakes w1 and w2. The rear wheel hydraulic circuit may be configured to transmit hydraulic pressure to a pair of rear wheel brakes w3 and w4.

[0028] The front wheel hydraulic circuit may include all or part of a first main control valve 131, a first main flow path 132, inlet valves 141 and 142, an inlet flow path, outlet valves 151 and 152, and an outlet flow path.

[0029] The first main flow path 132 can be connected to the first chamber 115 of the master cylinder 110 via the first master control valve 131. When the piston 113 moves forward according to a braking request, brake fluid can be delivered from the first chamber 115 through the first main flow path 132 to multiple wheel brakes w1 to w4. The first master control valve 131 can adjust the hydraulic pressure delivered from the first chamber 115 to the multiple wheel brakes w1 to w4. The first master control valve 131 can be a normally open solenoid valve that is normally open and operates to close upon receiving a shutdown signal from the controller (ECU).

[0030] The front wheel hydraulic circuit may include one or more inlet flow paths branching from the first main flow path 132 for transmitting hydraulic pressure to the front wheel brakes w1 and w2, respectively. Inlet valves 141 and 142 are installed in the inlet flow paths and can control the hydraulic pressure transmitted to the front wheel brakes w1 and w2, respectively, when braking is required.

[0031] The front wheel hydraulic circuit may include one or more outlet flow paths that connect the front wheel brakes w1 and w2 to a reservoir, respectively. Outlet valves 151 and 152 are installed in the outlet flow paths and can control the hydraulic pressure discharged from the front wheel brakes w1 and w2, respectively, when braking stops.

[0032] The rear wheel hydraulic circuit may include all or part of the second main control valve 133, the second main flow path 134, inlet valves 143 and 144, the inlet flow path, the outlet valves 153 and 154, and the outlet flow path.

[0033] The second main flow path 134 can be connected to the second chamber 117 of the master cylinder 110 via the second main control valve 133. When the piston 113 moves backward according to a braking request, brake fluid can be delivered from the second chamber 117 through the second main flow path 134 to the multiple wheel brakes w1 to w4. The second main control valve 133 can adjust the hydraulic pressure delivered from the second chamber 117 to the multiple wheel brakes w1 to w4. The second main control valve 133 can be a normally open solenoid valve that is normally open and operates to close upon receiving a closing signal from the controller.

[0034] The rear wheel hydraulic circuit may include one or more inlet flow paths branching from the second main flow path 134 for transmitting hydraulic pressure to the rear wheel brakes w3 and w4, respectively. Inlet valves 143 and 144 are installed in the inlet flow paths and can control the hydraulic pressure transmitted to the front wheel brakes w3 and w4, respectively, when braking is required.

[0035] The rear wheel hydraulic circuit may include one or more outlet flow paths that connect the front wheel brakes W3 and W4 to a reservoir, respectively. Outlet valves 153 and 154 are installed in the outlet flow paths and can control the hydraulic pressure discharged from the front wheel brakes W3 and W4, respectively, when braking stops.

[0036] Inlet valves 141 to 144 are arranged upstream of wheel brakes w1 to w4 and may be normally open solenoid valves that operate to close when a close signal is received from the controller. Outlet valves 151 to 154 are arranged downstream of inlet valves 141 to 144 and may be normally closed solenoid valves that operate to open when an open signal is received from the controller.

[0037] An electro-hydraulic brake 100 according to one embodiment of the present disclosure may further include an auxiliary actuator 120. The auxiliary actuator 120 may include a second motor 121 and a pump unit. The second motor may be a direct current (DC) motor.

[0038] When the master cylinder 110 cannot transmit hydraulic pressure to the multiple wheel brakes w1, w2, w3, and w4 due to a failure of the first motor 111 or the ball screw of the master cylinder 110, an auxiliary actuator 120 can be used. The second motor 121 is controlled by the first controller 180 and the second controller 190, and a pump unit can be used to generate brake fluid pressure. Because the electro-hydraulic brake 100 includes the auxiliary actuator 120, the actuator is dual, thus improving the reliability of the braking system.

[0039] The pump unit may include a front wheel pump unit 123 connected to the front wheel hydraulic circuit and a rear wheel pump unit 125 connected to the rear wheel hydraulic circuit. The front wheel pump unit 123 can deliver hydraulic pressure to multiple wheel brakes w1, w2, w3, and w4 via a first auxiliary flow path 122 connected to the front wheel inlet flow path. The rear wheel pump unit 125 can deliver hydraulic pressure to multiple wheel brakes w1, w2, w3, and w4 via a second auxiliary flow path 124 connected to the rear wheel inlet flow path.

[0040] The pump unit may include an odd number of piston pumps. By connecting an odd number of piston pumps to a second motor 121, it is possible to reduce the pulsation and noise generated in the existing ESC.

[0041] Furthermore, compared to the rear wheel pump unit 125, the front wheel pump unit 123 can accommodate more piston pumps out of an odd number. For example, when the pump unit includes three piston pumps, two piston pumps can be located in the front wheel pump unit 123, and one piston pump can be located in the rear wheel pump unit 125. Because the front wheel pump unit 123 has more piston pumps than the rear wheel pump unit 125, the auxiliary actuator 120 can be used to generate braking force at a higher boost rate in the event of a failure in the master cylinder 110 and the rear wheel hydraulic circuit.

[0042] An electro-hydraulic brake 100 according to one embodiment of the present disclosure may further include a mixing valve 161, a mixing flow path, and a recovery valve 171.

[0043] The mixing valve 161 can be installed in a mixing path connecting the front wheel hydraulic circuit and the rear wheel hydraulic circuit. The mixing valve 161 controls the hydraulic pressure transmitted between the front wheel hydraulic circuit and the rear wheel hydraulic circuit. The mixing valve 161 can be a low-pressure switching valve (LSV). The mixing valve 161 can be a normally closed solenoid valve that is normally closed and opens upon receiving an open signal.

[0044] According to one embodiment of the present disclosure, the electro-hydraulic brake 100 can achieve redundancy by dual-configuring a first controller 180 and a second controller 190. That is, by dual-equipping the controllers in a single mechanical package, even if one controller fails, the other controller can guarantee the braking force of the electro-hydraulic brake 100.

[0045] The first controller 180 and the second controller 190 may each include a 46-pin connector and a microcontroller unit (MCU). Multiple solenoid valves of the front wheel hydraulic circuit can be connected to the first controller 180 and the second controller 190. That is, even if the first controller 180 fails, the front wheel hydraulic circuit can still be controlled using the second controller 190. Multiple solenoid valves of the rear wheel hydraulic circuit can be connected to the first controller 180.

[0046] Under normal conditions, the first controller 180 and the second controller 190 can cooperate to control the electro-hydraulic brake 100. When the first controller 180 fails, the second controller 190 can control the conventional braking system (CBS). When the second controller 190 fails, the first controller 180 can control the electronic parking brake (EPB).

[0047] When the electro-hydraulic brake 100 is not malfunctioning, the first controller 180 and the second controller 190 can control the first motor 111, and the first controller 180 controls the second main control valve 133 and the mixing valve 161, thus generating braking force.

[0048] When a braking request is generated, the first controller 180 and the second controller 190 cause the first motor 111 to rotate, and the ball screw and piston 113 connected to the first motor 111 move forward, thus generating hydraulic pressure in the master cylinder 110. As the piston 113 moves forward, the hydraulic pressure generated in the master cylinder 110 can be transmitted to multiple wheel brakes w1, w2, w3, and w4 via the first main control valve 131, multiple inlet valves 141 to 144, and mixing valve 161.

[0049] When a braking request is generated, the first controller 180 can control the second main control valve 133 and the mixing valve 161.

[0050] The first controller 180 can close the second main control valve 133 by sending a closing signal to the second main control valve 133.

[0051] The first controller 180 can open the mixing valve 161 by sending an open signal to the mixing valve 161.

[0052] When the electro-hydraulic brake 100 is functioning correctly, the first controller 180 can control the second main control valve 133 upon releasing the brake pedal. The first controller 180 can eliminate residual pressure by opening and then closing the second main control valve 133 again. Upon releasing the brake pedal, hydraulic pressure can be transmitted to the reservoir via the outlet flow path.

[0053] When a rear wheel hydraulic circuit fails, the first controller 180 can close the mixing valve 161 by sending a shutdown signal to the mixing valve 161. The electro-hydraulic brake 100 can then generate braking force solely for use by the front wheel hydraulic circuit by closing the mixing valve 161. Furthermore, upon releasing the brake pedal, the first controller 180 and the second controller 190 can eliminate residual pressure by controlling the front wheel outlet valves 151 and 152. The electro-hydraulic brake 100 can generate braking force using only the front wheel hydraulic circuit and the EPB. Therefore, the electro-hydraulic brake 100 can exhibit approximately 65% ​​of its performance under normal conditions. Functions of the electro-hydraulic brake 100, such as the Electronic Stability Control (ESC) system and the Anti-lock Braking System (ABS), can be switched to a degraded mode relative to the normal state. Additionally, steering and cooperative control are possible to ensure vehicle stability.

[0054] When a failure occurs in the front wheel hydraulic circuit, the first controller 180 can close the first main control valve 131 by sending a close signal to the first main control valve 131. The first controller 180 can open the second main control valve 133 by sending an open signal to the second main control valve 133. By closing the first and second main control valves 131 and 133, the electro-hydraulic brake 100 can generate braking force using only the rear wheel hydraulic circuit. Furthermore, the first controller 180 can eliminate residual pressure by controlling the recovery valve 171 when the brake pedal is released. The electro-hydraulic brake 100 can then generate braking force using only the rear wheel hydraulic circuit and EPB. Therefore, the electro-hydraulic brake 100 can exhibit approximately 40% of its normal performance. Functions such as ESC and ABS can also be switched to a degraded mode compared to the normal state. Additionally, steering and cooperative control are possible to ensure vehicle stability.

[0055] Even if the second controller 190 malfunctions, hydraulic pressure can still be transmitted to the multiple wheel brakes w1, w2, w3, and w4 in the same manner as under normal conditions. When a braking request is generated, the first controller 180 rotates the first motor 111, causing the ball screw and piston 113 connected to the first motor 111 to move forward, thus generating hydraulic pressure in the master cylinder 110. As the piston 113 moves forward, the hydraulic pressure generated in the master cylinder 110 can be transmitted to the multiple wheel brakes w1, w2, w3, and w4 via the first master control valve 131, multiple inlet valves 141 to 144, and mixing valve 161. When a braking request is generated, the first controller 180 can control the second master control valve 133 and the mixing valve 161. The first controller 180 can close the second master control valve 133 by sending a closing signal to the second master control valve 133. The first controller 180 can open the mixing valve 161 by sending an opening signal to the mixing valve 161. The brake pedal is released in the same manner as... Figure 3 The situation is the same. That is, even if the second controller 190 fails, the first controller 180 can still control multiple solenoid valves in the same way as in normal operation.

[0056] When the second controller 190 malfunctions, the rear left EPB controlled by the second controller 190 cannot be used. Furthermore, since the first controller 180 and the second controller 190 control the first motor 111 in a 1:1 ratio, the output of the first motor 111 can be limited to 50% of its normal output.

[0057] When the first controller 180 fails, the electro-hydraulic brake 100 can generate braking force using only the front wheel hydraulic circuit. The electro-hydraulic brake 100 can also generate braking force using only the front wheel hydraulic circuit and the rear left EPB. Therefore, the electro-hydraulic brake 100 can exhibit approximately 65% ​​of its normal performance. Functions such as ESC and ABS can be switched to a degraded mode compared to the normal state. Additionally, steering and cooperative control are possible to ensure vehicle stability.

[0058] Figure 2 This is a table showing the control relationships between a first controller and a second controller of an electro-hydraulic brake according to one embodiment of the present disclosure and a plurality of solenoid valves.

[0059] Reference Figure 2 The first controller 180 can control the front wheel hydraulic circuit and the rear wheel hydraulic circuit. The first controller 180 can control the first main control valve 131, the second main control valve 133, the inlet valves 141 to 144, the outlet valves 151 to 154, the mixing valve 161, the recovery valve 171, the first motor 111, the pressure sensor 162, and the rear wheel right EPB.

[0060] The second controller 190 can control the front wheel hydraulic circuit. The second controller 190 can control the first main control valve 131, front wheel inlet valves 141 and 142, front wheel outlet valves 151 and 152, the first motor 111, the pressure sensor 162, and the rear wheel left EPB. The first controller 180 and the second controller 190 can cooperate with each other through real-time communication to control the hydraulic circuit.

[0061] The electro-hydraulic brake 100 may include two or more pressure sensors 162, and the pressure sensors 162 may communicate with a first controller 180 and a second controller 190. The pressure sensors 162 may be located in the front wheel hydraulic circuit. However, the pressure sensors 162 are not limited to the location described in the above embodiment. The auxiliary actuator 120 may be controlled by the first controller 180 and the second controller 190.

[0062] Even if the first controller 180 fails, the second controller 190 can be used to control the first main control valve 131, the front wheel inlet valves 141 and 142, and the front wheel outlet valves 151 and 152 connected to the second controller 190.

[0063] Figure 3 This is a hydraulic circuit diagram showing the brake oil flow when a fault occurs in the master cylinder of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0064] Reference Figure 3 When the ball screws of the first motor 111 and the master cylinder 110 fail, the electro-hydraulic brake 100 can use the auxiliary actuator 120. The auxiliary actuator 120 can generate brake fluid pressure using the pump unit by operating the second motor 121.

[0065] The pump unit may include an odd number of piston pumps. By connecting an odd number of piston pumps to the second motor 121, it is possible to reduce the pulsation and noise generated in the existing ESC. In this case, the piston pumps are all of the same specification, and two piston pumps may be arranged at the front wheel pump unit 123 connected to the front wheel hydraulic circuit with a large amount of the necessary fluid, and one piston pump may be arranged at the rear wheel pump unit 125 connected to the rear wheel hydraulic circuit.

[0066] When a braking request is generated, the first controller 180 can control the first main control valve 131, the second main control valve 133, and the mixing valve 161. The first controller 180 can close the second main control valve 133 by sending a close signal to the first main control valve 131 and the second main control valve 133. The first controller 180 can open the mixing valve 161 by sending an open signal to the mixing valve 161. That is, by opening the mixing valve 161, the pressure of the brake fluid can be increased using three pistons.

[0067] Figure 4A and Figure 4B This is a graph comparing the operating noise of the piston pump of an electro-hydraulic brake according to one embodiment of the present disclosure with that of a conventional electro-hydraulic brake. Figure 5A and Figure 5B This is a graph comparing the displacement of the piston pump of an electro-hydraulic brake according to one embodiment of the present disclosure and a conventional electro-hydraulic brake.

[0068] Reference Figure 4A , Figure 4B , Figure 5A and Figure 5B The application of three piston pumps can improve the noise, vibration, and acoustic roughness (NVH) performance of the electro-hydraulic brake 100.

[0069] Figure 4A This is a diagram showing the NVH (Noise, Vibration, and Harshness) of a conventional electro-hydraulic brake system excluding the shock absorber. (See reference...) Figure 4A It can be seen that the NVH of existing electro-hydraulic brakes, excluding shock absorbers, is very high.

[0070] Figure 4B This is a diagram illustrating the NVD of an electro-hydraulic brake 100 comprising three piston pumps according to one embodiment of the present disclosure. (See also...) Figure 4B As can be seen, the NVH of the electro-hydraulic brake 100 is reduced compared to existing electro-hydraulic brakes. Noise is reduced by using an odd number of piston pumps to counteract the pulsation generated by the piston pump.

[0071] Reference Figure 5A and Figure 5B The brake fluid displacement of the piston pump in the electro-hydraulic brake 100 according to one embodiment can be compared with that of a conventional electro-hydraulic brake. The displacements ESCMC1 and MC2 of the piston pump in a conventional electro-hydraulic brake are larger than the displacements Premium MC1 and MC2 of the piston pump in the electro-hydraulic brake 100 according to one embodiment, but can only discharge half the brake fluid for one rotation of the first motor 111. Therefore, the average displacement ESC Average of the conventional electro-hydraulic brake is smaller than the average displacement Premium Average of the electro-hydraulic brake 100 according to one embodiment.

[0072] Therefore, conventional electro-hydraulic brakes discharge brake fluid discontinuously, but the electro-hydraulic brake 100 according to one embodiment discharges brake fluid continuously, resulting in less pulsation and excellent NVH performance.

[0073] Figure 6 This is a diagram illustrating another embodiment of an electro-hydraulic brake according to one embodiment of the present disclosure. Figure 7This is a diagram illustrating another embodiment of an electro-hydraulic brake according to one embodiment of the present disclosure.

[0074] Reference Figure 6 This allows for modification of the fluid inlet flow path structure of the pump unit in the auxiliary actuator 120 of the electro-hydraulic brake 100. The auxiliary actuator 120 can directly connect the fluid inlet flow path of the pump unit to the reservoir instead of the master cylinder 110.

[0075] By directly connecting the inlet flow path of the pump unit of the auxiliary actuator 120 to the reservoir, the master cylinder 110 can be used to increase the discharge of brake fluid when a large amount of brake fluid needs to be discharged.

[0076] Reference Figure 7 The number of piston pumps in the pump unit of the auxiliary actuator 120 in the electro-hydraulic brake 100 can be changed. Three piston pumps can be arranged at the front wheel pump unit 123 and three piston pumps can be arranged at the rear wheel pump unit 125. That is, three piston pumps can be arranged in each of the front wheel hydraulic circuit and the rear wheel hydraulic circuit.

[0077] By arranging three piston pumps at each hydraulic circuit, the boosting performance and NVH performance of the electro-hydraulic brake 100 can be improved. Furthermore, it allows for a reduction in the size of each piston pump.

[0078] According to one embodiment, the electro-hydraulic brake has a controller with only dual design in a single mechanical package, which has the effect of enabling redundancy in the vehicle's braking system and reducing installation space and manufacturing costs by reducing the number of components.

[0079] According to one implementation, the electro-hydraulic brake reduces noise by counteracting the pulsations generated by the piston pump, thus having the effect of not transmitting a sense of disharmony to the driver.

[0080] Although exemplary embodiments of this disclosure have been described for illustrative purposes, those skilled in the art will understand that various modifications, additions, and substitutions can be made without departing from the spirit and scope of the claimed invention. Therefore, exemplary embodiments of this disclosure have been described for the sake of brevity and clarity. The scope of the technical concept of these embodiments is not limited by the illustrations. Therefore, those skilled in the art will understand that the scope of the claimed invention is not limited to the embodiments explicitly described above, but rather to the claims and their equivalents.

[0081] Cross-references to related applications

[0082] This application is based on and claims priority to Korean Patent Application No. 10-2021-0151788, filed on November 5, 2021, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. An electro-hydraulic brake comprising: a plurality of wheel brakes configured to supply a braking force to wheels of a vehicle; a reservoir storing brake oil; a master cylinder connected to the reservoir and configured to generate a hydraulic pressure in cooperation with a first motor; an auxiliary actuator including a second motor and a pump unit having three or more piston pumps coupled to the second motor, and configured to transmit the hydraulic pressure to the plurality of wheel brakes when the master cylinder fails; a hydraulic circuit configured to selectively transmit the hydraulic pressure to the plurality of wheel brakes, and including a front wheel hydraulic circuit configured to transmit the hydraulic pressure to a pair of front wheel brakes, a rear wheel hydraulic circuit configured to transmit the hydraulic pressure to a pair of rear wheel brakes, and a plurality of solenoid valves; a first controller configured to control the first motor and the hydraulic circuit in accordance with a brake input; and a second controller configured to control the first motor and the front wheel hydraulic circuit when the first controller fails, and wherein the first controller and the second controller are configured to control the second motor to transmit the hydraulic pressure to the plurality of wheel brakes when the master cylinder fails.

2. The electro-hydraulic brake according to claim 1, wherein, the master cylinder has a double structure, an inner space of which is divided by a piston into a first chamber and a second chamber, and the master cylinder supplies the hydraulic pressure to the plurality of wheel brakes in accordance with a brake signal of one or more of the first controller and the second controller.

3. The electro-hydraulic brake according to claim 2, wherein, the front wheel hydraulic circuit includes: a first master control valve configured to control the hydraulic pressure supplied from the first chamber; a plurality of inlet valves configured to control the hydraulic pressure transmitted to at least one of the pair of front wheel brakes; and a plurality of outlet valves configured to control the hydraulic pressure transmitted from the at least one of the pair of front wheel brakes to the reservoir.

4. The electro-hydraulic brake according to claim 3, wherein, the front wheel hydraulic circuit further includes: a first master flow path connecting the master cylinder and the first master control valve; a plurality of inlet flow paths connecting the first master control valve and the at least one of the pair of front wheel brakes via the inlet valves; and a plurality of outlet flow paths connecting the at least one of the pair of front wheel brakes and the reservoir.

5. The electro-hydraulic brake according to claim 2, wherein, the rear wheel hydraulic circuit includes: a second master control valve configured to control the hydraulic pressure supplied from the second chamber; a plurality of inlet valves configured to control the hydraulic pressure transmitted to at least one of the pair of rear wheel brakes; and a plurality of outlet valves configured to control the hydraulic pressure transmitted from the at least one of the pair of rear wheel brakes to the reservoir.

6. The electro-hydraulic brake according to claim 5, wherein, the rear wheel hydraulic circuit further includes: a second master flow path connecting the master cylinder and the second master control valve; a plurality of inlet flow paths connecting the second master control valve and the at least one of the pair of rear wheel brakes via the inlet valve; and a plurality of outlet flow paths connecting the at least one of the pair of rear wheel brakes and the reservoir.

7. The electro-hydraulic brake of claim 1, wherein, The first motor has a dual winding structure, and each of the first controller and the second controller controls 50% of the first motor.

8. The electro-hydraulic brake of claim 1, wherein, The first controller is configured to control the first motor and the hydraulic circuit when the second controller fails.

9. The electro-hydraulic brake of claim 1, wherein, The first controller controls one rear wheel electronic parking brake (EPB), and The second controller controls the other rear wheel EPB.

10. The electro-hydraulic brake of claim 1, wherein, The first controller and the second controller control the hydraulic circuit by cooperating with each other by means of real-time communication.

11. The electro-hydraulic brake of claim 1, further comprising: a mixing flow path connecting the front wheel hydraulic circuit and the rear wheel hydraulic circuit; and a mixing valve installed in the mixing flow path and configured to selectively deliver the hydraulic pressure to the plurality of wheel brakes.

12. The electro-hydraulic brake of claim 1, further comprising a pressure sensor having two or more channels, wherein the pressure sensor is in communication with the first controller and the second controller.

13. The electro-hydraulic brake according to claim 12, wherein, The pressure sensor is disposed in the front wheel hydraulic circuit.

14. The electro-hydraulic brake of claim 1, wherein, The pump unit includes a front wheel pump unit connected to the front wheel hydraulic circuit and a rear wheel pump unit connected to the rear wheel hydraulic circuit.

15. The electro-hydraulic brake according to claim 14, wherein, The front wheel pump unit includes the same number or more of piston pumps as the rear wheel pump unit.

16. The electro-hydraulic brake of claim 14, wherein, The front wheel pump unit and the rear wheel pump unit each include an odd number of piston pumps.

17. The electro-hydraulic brake of claim 1, wherein, The second motor is a direct current motor and is controlled by the first controller and the second controller.

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