KR102016372B1 - Electric brake system - Google Patents

Abstract

An electronic brake system is disclosed. According to an embodiment of the present invention, a reservoir having oil stored therein, first and second hydraulic ports having a master cylinder coupled to the reservoir to receive the oil, and detecting the displacement of the brake pedal coupled to the master cylinder In an electronic brake system including a pedal displacement sensor and a simulation device connected to the master cylinder to provide a reaction force according to the stepping force of the brake pedal, when the brake pedal is operated, it is output as an electrical signal through the pedal displacement sensor. A hydraulic pressure supply device configured to move a double-acting piston by operating a motor and converting the rotational force of the motor into a linear motion; A hydraulic control unit having first and second hydraulic circuits for receiving a hydraulic pressure by a force generated by the hydraulic pressure supply device and controlling a flow of hydraulic pressure delivered to caliper brakes provided at each wheel; First and second cut valves provided in first and second backup passages connecting the first and second hydraulic ports and the first and second hydraulic circuits to control the flow of hydraulic pressure; And an electronic control unit for controlling the motor and the valves based on the hydraulic pressure information and the pedal displacement information, wherein both sides of the double acting piston have a first hydraulic chamber and a second hydraulic chamber which generate hydraulic pressure according to the reciprocating movement of the double acting piston. Electronic brake system can be provided.

Description

Electronic brake system

The present invention relates to an electronic brake system, and more particularly, to an electronic brake system that simplifies the structure and enables precise pressure control.

Vehicles are equipped with a brake system for braking. Recently, various kinds of systems have been proposed for obtaining a stronger and more stable braking force. An example of a brake system is an anti-lock brake system (ABS) to prevent wheel slippage during braking and a brake traction control system (BTCS) to prevent slippage of driving wheels during rapid start or acceleration of a vehicle. Traction Control System), a vehicle dynamic control system (VDC) for stably maintaining driving conditions by controlling brake hydraulic pressure by combining anti-lock brake system and traction control.

The electronic brake system includes a plurality of solenoid valves for controlling braking hydraulic pressure delivered to a caliper brake (called a hydraulic brake or a disk brake) mounted on a vehicle wheel, and a pair for temporarily storing oil discharged from a wheel cylinder. Low pressure accumulator and high pressure accumulator, a motor and pump for forcibly pumping oil of the low pressure accumulator, a plurality of check valves for preventing the reverse flow of oil, an electronic control unit for controlling the operation of the solenoid valve and the motor ( ECUs, which are compactly embedded in hydraulic blocks made of aluminum. In addition, when the driver presses the brake pedal, a hydraulic pressure supply device for supplying pressure to the wheel cylinder is provided by receiving the driver's braking intention as an electrical signal from a pedal displacement sensor that detects the displacement of the brake pedal.

An electronic brake system provided with such a hydraulic pressure supply device is disclosed in US Patent Application Publication No. 2012/0091787. According to the disclosed literature, the hydraulic pressure supply device is configured to generate a braking pressure by operating a motor according to the pedaling force of the brake pedal. At this time, the braking pressure is generated by converting the rotational force of the motor into linear motion to pressurize the piston.

However, the above-described electronic brake system has a hydraulic pressure supply device that generates pressure, and has a single-acting structure, and when the pressure is regenerated or boosted to the generated pressure, the pressurized piston is returned to its original position and then operated again. It has a problem that it is difficult to quickly generate pressure and precise control.

In addition, to control the brake system electronically, in order to perform various functions, there is a problem that the structure of the plurality of valves and the flow path is complicated.

US published patent US 2012/0091787 (HITACHI, LTD) April 19, 2012.

The electronic brake system according to an embodiment of the present invention configures the hydraulic pressure generated from the hydraulic pressure supply device in a double-acting manner to quickly generate pressure when boosting the pressure regeneration and the generated pressure, as well as to enable precise pressure control. Can be.

In addition, the electronic brake system according to an embodiment of the present invention can simplify the configuration by minimizing the number of valves for controlling the flow of hydraulic pressure, and braking is performed by the driver's effort even when the brake system is abnormally operated. have.

According to an embodiment of the present invention, a reservoir having oil stored therein, first and second hydraulic ports having a master cylinder coupled to the reservoir to receive the oil, and detecting the displacement of the brake pedal coupled to the master cylinder In an electronic brake system including a pedal displacement sensor and a simulation device connected to the master cylinder to provide a reaction force according to the stepping force of the brake pedal, when the brake pedal is operated, it is output as an electrical signal through the pedal displacement sensor. A hydraulic pressure supply device configured to move a double-acting piston by operating a motor and converting the rotational force of the motor into a linear motion; A hydraulic control unit having first and second hydraulic circuits for receiving a hydraulic pressure by a force generated by the hydraulic pressure supply device and controlling a flow of hydraulic pressure delivered to caliper brakes provided at each wheel; First and second cut valves provided in first and second backup passages connecting the first and second hydraulic ports and the first and second hydraulic circuits to control the flow of hydraulic pressure; And an electronic control unit that controls the motor and the valves based on the hydraulic pressure information and the pedal displacement information, wherein a first hydraulic chamber and a second hydraulic chamber are provided on both sides of the double acting piston, and the double acting piston is advanced. Thereby generating a hydraulic pressure of the second hydraulic chamber, and the double acting piston is retracted to generate a hydraulic pressure of the first hydraulic chamber.

In addition, the hydraulic pressure supply device, the motor for generating a rotational force by the electrical signal of the pedal displacement sensor; A power converter converting the rotational motion of the motor into a linear motion; A double-acting piston connected to the power converter and linearly moving; And a hydraulic cylinder in which the double-acting piston is slidably provided and having a first and a second hydraulic chamber with the double-acting piston interposed therebetween.

In addition, the first hydraulic chamber may be connected to the first hydraulic circuit by a first hydraulic passage, and the second hydraulic chamber may be connected to the second hydraulic circuit by a second hydraulic passage.

In addition, the hydraulic control unit, the first hydraulic control unit provided in the first hydraulic passage for controlling the flow of the hydraulic pressure; A second hydraulic controller provided in the second hydraulic passage to control the flow of the hydraulic pressure; And a normally open inlet valve disposed at an upstream side of the caliper brake to control the transfer of hydraulic pressure to the caliper brake.

The first hydraulic controller may include a first switching valve provided in the first hydraulic passage, a first dump valve provided in a passage connecting the first hydraulic passage and the reservoir, and the second hydraulic controller may include: And a second switching valve provided in the second hydraulic flow path, and a second dump valve provided in a flow path connecting the second hydraulic flow path and the reservoir.

In addition, the first and second dump valves are connected to the first and second hydraulic chambers, respectively, to be opened or closed along the direction of the forward and backward movement of the double acting piston, and the oil is sucked from the reservoir to the first hydraulic chamber or the first. 2 Can fill hydraulic chamber.

The first and second switching valves and the first and second dump valves may be normally closed solenoid valves that are normally closed and operate to open the valves upon receiving an open signal.

The apparatus may further include a balance valve disposed downstream of the first and second hydraulic controllers between the first and second hydraulic passages and connecting and disconnecting the first and second hydraulic circuits.

In addition, the balance valve may be connected to the first and second backup passages.

In addition, the balance valve may be provided as a normally closed solenoid valve that is normally closed but operates to open the valve upon receiving an open signal.

In addition, the first and second cut valves may be provided as solenoid valves of a normal open type which are open in a normal state and operate to close the valve when receiving a close signal from the electronic control unit.

The electronic brake system according to an embodiment of the present invention may generate a hydraulic pressure when the piston moves forward and backward by configuring the hydraulic pressure generated from the hydraulic pressure supply device in a double-acting manner. Thus, when boosting the pressure regeneration and the generated pressure, there is an advantage that the pressure can be quickly regenerated and boosted compared to the method of pressurizing the piston again after returning to the original position.

In addition, by minimizing the number of valves for controlling the flow of hydraulic pressure has the advantage that can be simplified compared to the conventional structure. As a result, the size of the brake system, that is, the size of the modulator block in which the valves are installed, can be reduced, thereby realizing a low cost.

In addition, there is an effect that precise pressure control is possible by controlling the motor and the valve in conjunction. In addition, two hydraulic circuits are connected to each of the two wheels for independent control, and the hydraulic supply unit can be interlocked according to the pressure and prioritization logic required for each wheel to increase the control range. There are advantages to it.

Furthermore, in the event of a breakdown of the brake system, the driver's effort can be transmitted directly to the master cylinder to enable braking of the vehicle, thereby providing stable braking force.

The present invention will be described in detail with reference to the following drawings, but these drawings illustrate preferred embodiments of the present invention, and the technical concept of the present invention is not limited to the drawings and should not be interpreted.
1 is a hydraulic circuit diagram illustrating a non-braking state of an electronic brake system according to an exemplary embodiment of the present invention.
2 is a hydraulic circuit diagram illustrating a state in which an electronic brake system normally brakes according to an exemplary embodiment of the present invention.
3 is a hydraulic circuit diagram illustrating a state in which an electronic brake system is normally braked and released according to an exemplary embodiment of the present invention.
4 and 5 are hydraulic circuit diagrams for explaining the ABS operating state through the electronic brake system according to an embodiment of the present invention, respectively.
6 is a hydraulic circuit diagram illustrating an abnormal operation state of the electronic brake system according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention is not limited to the embodiments presented herein but may be embodied in other forms. The drawings may omit illustrations of parts not related to the description in order to clarify the present invention, and may be exaggerated to some extent in order to facilitate understanding.

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

Referring to the drawings, the electronic brake system is typically, the master cylinder 20 for generating a hydraulic pressure, the reservoir 30 coupled to the upper portion of the master cylinder 20 to store oil, and the pedal force of the brake pedal 10 Displacement of the caliper brake 40 and the brake pedal 10 that pressurizes the master cylinder 20 and the hydraulic pressure is transmitted to brake the wheels RR, RL, FR, and FL. It is provided with a pedal displacement sensor (11) for detecting.

At this time, the master cylinder 20 may be composed of at least one chamber to generate a hydraulic pressure, but as shown, the first piston 21a and the second piston 22a are formed to have two chambers. The first piston 21a is in contact with the input rod 12. The master cylinder 20 has two chambers to ensure safety in case of failure. For example, the first of the two chambers is connected to the right front wheel FR and the left rear wheel RL of the vehicle, and the remaining chambers are connected to the left front wheel FL and the right rear wheel RR. Alternatively, the first of the two chambers may be connected to the two front wheels FR and FL and the remaining chambers to the two rear wheels RR and RL. As such, the two chambers are independently configured to allow braking of the vehicle even when one chamber fails. In addition, the master cylinder 20 is formed with first and second hydraulic ports 24a and 24b through which hydraulic pressure is discharged from the two chambers.

The first spring 21b is disposed between the first piston 21a and the second piston 22a of the master cylinder 20, and the second spring 22b is disposed between the end of the master cylinder 20. A spring 22b is provided. That is, the first spring 21b and the second spring 22b are provided in the two chambers, respectively, and the elastic force is stored as the first piston 21a and the second piston 22a are compressed. The elastic force pushes back the first and second pistons 21a and 22a when the force pushing the first piston 21a becomes smaller than the elastic force.

On the other hand, as the input rod 12 pressurizing the first piston 21a of the master cylinder 20 comes into close contact with the first piston 21a, a gap between the master cylinder 20 and the input rod 12 ( gap) does not exist. That is, when the brake pedal 10 is released, the master cylinder 20 is directly pressed without a pedal invalid stroke section.

The electronic brake system according to the present invention receives the driver's braking intention from the pedal displacement sensor 11 for detecting the displacement of the brake pedal 10 as an electrical signal, and a hydraulic pressure supply device 100 which operates mechanically, respectively. A hydraulic control unit having first and second hydraulic circuits 201 and 202 for controlling the flow of hydraulic pressure delivered to the caliper brakes 40 provided on the wheels RR, RL, FR, and FL. 200 and first and second backup passages 251 and 252 connecting the first and second hydraulic ports 24a and 24b and the first and second hydraulic circuits 201 and 202 to flow the hydraulic pressure. Based on the first and second cut valve (261, 262), the master cylinder 20 to control the control device for providing a reaction force to the brake pedal 10 and the hydraulic pressure information and pedal displacement information For controlling the hydraulic pressure supply device 100 and the valves 54, 204, 221, 222, 231, 232, 240, 261, 262. It includes a magnetic control unit (not shown).

The hydraulic pressure supply device 100 is provided with a predetermined space to receive and store oil, and includes a hydraulic cylinder 110 in which hydraulic chambers 111 and 112 are formed therein, and a double-acting piston 120 provided in the hydraulic cylinder 110 to linearly move. ) And a power converter 130 for linearly moving the double-acting piston 120 by converting the rotational motion of the motor 140 and the motor 140 generating the rotational force by the electrical signal of the pedal displacement sensor 11 into a linear motion. ). In this case, the hydraulic chambers 111 and 112 are divided into first and second hydraulic chambers 111 and 112 on both sides of the double-acting piston 120 with the double-acting piston 120 interposed therebetween. That is, as the sealing member 124 is installed on the outer surface of the double acting piston 120 and tightly adhered to the inner surface of the hydraulic cylinder 110, the interior of the hydraulic cylinder 110 is divided into two hydraulic chambers 111 and 112. Will be. The areas of the two hydraulic chambers 111 and 112 may be formed to be the same or different from each other.

The hydraulic pressure generated by the first and second hydraulic chambers 111 and 112 is transmitted to each of the wheels RR, RL, FR, and FL of the hydraulic control unit 200 to be described later. That is, the first hydraulic chamber 111 is connected to the first hydraulic circuit 201 to be described later through the first hydraulic passage 211, and the second hydraulic chamber 112 is described later via the second hydraulic passage 212. The second hydraulic circuit 202 to be connected.

The double-acting piston 120 for pressurizing the first and second hydraulic chambers 111 and 112 is connected to a power converter 130 for converting the rotational force of the motor 140 into a linear motion in the hydraulic cylinder 110. Sliding is moved.

The motor 140 is an electric motor that generates a rotational force through a signal output from an electronic control unit (not shown). The motor 140 includes a stator 141, a rotor 142, and a rotation shaft 143 coupled with the rotor 142 to form an electric motor. The rotating force is generated by the control unit in the forward or reverse direction. Since the motor 140 is well known in the art, a detailed description thereof will be omitted.

The power converter 130 is a device for converting the rotational force into a linear motion, for example may be composed of a ball screw nut assembly. That is, the screw 133 integrally formed with the rotation shaft 143 of the motor 140, and the ball nut 132 is screwed with the screw 133 in a limited rotation state and linearly moving according to the rotation of the rotation shaft 143. It can be configured as. At this time, the rotating shaft 143 is made to perform the function of the screw 133.

On the other hand, although not shown, it may be composed of a ball nut that is rotated by receiving a rotational force from the rotational axis of the motor, and a screw that is screwed with the ball nut in a limited rotation to the linear movement according to the rotation of the ball nut. Since the structure of such a ball screw nut assembly is a well-known technique for converting a rotary motion into a linear motion, a detailed description thereof will be omitted. In addition, it should be understood that the power converter 130 according to the present invention may employ any structure as long as it can convert rotational motion into linear motion in addition to the structure of the ball screw nut assembly.

As described above, the double-acting piston 120 of the hydraulic pressure supply device 100 having the double-acting structure moves linearly along the rotational direction of the motor 140 and pressurizes the first hydraulic chamber 111 and the second hydraulic chamber 112. As a result, hydraulic pressure is generated, and precise control is possible by controlling the rotation angle or the speed through the motor 140.

Referring back to FIG. 1, the hydraulic control unit 200 includes a first hydraulic circuit 201 and a second hydraulic circuit 202 that receive two hydraulic pressures to control two wheels, respectively. At this time, the wheel controlled by the first hydraulic circuit 201 is composed of the right front wheel (FR) and the left rear wheel (RL), the wheel controlled by the second hydraulic circuit 202 is the left front wheel (FL) and the right It may be made of the rear wheel (RR). Each wheel FR, FL, RR, RL is provided with a caliper brake 40 is supplied with a hydraulic pressure to brake. That is, the hydraulic control unit 200 receives the hydraulic pressure from the hydraulic pressure supply device 100 through the first hydraulic passage 211 and the second hydraulic passage 212 connected to the first and second hydraulic circuits 201 and 202. A first hydraulic controller configured by a plurality of valves to receive and control the flow of the hydraulic pressure, and an inlet valve 204 disposed upstream of the second hydraulic controller and the caliper brake 40.

The first hydraulic controller is provided in the first hydraulic passage 211 to control the flow of the hydraulic pressure. More specifically, the first hydraulic control unit is provided in the first hydraulic passage 211, the first switching valve 221 for controlling the hydraulic pressure transmitted to the caliper brake 40, the first hydraulic passage 211 and the reservoir 30 ) Is provided with a first dump valve 222 provided in a flow path for connecting.

The second hydraulic controller is provided in the second hydraulic passage 212 to control the flow of the hydraulic pressure. More specifically, the second hydraulic control unit is provided in the second hydraulic passage 212, the second switching valve 231 for controlling the hydraulic pressure transmitted to the caliper brake 40, the second hydraulic passage 212 and the reservoir 30 ) Is provided with a second dump valve (232) provided in the flow path for connecting.

The opening and closing operations of the first and second switching valves 221 and 231 are independently controlled by the electronic control unit, and the hydraulic pressure generated from the hydraulic pressure supply device 100 is transmitted to the caliper brake 40. That is, the first switching valve 221 controls the hydraulic pressure supplied to the first hydraulic circuit 201, and the second switching valve 231 is configured to control the hydraulic pressure supplied to the second hydraulic circuit 202.

In addition, the first and second dump valves 222 and 232 may be opened or closed in a direction in which the double acting piston 120 moves forward and backward, and the hydraulic pressure flows in the first hydraulic chamber 111 and the second hydraulic chamber 112. Of course, the oil may be sucked from the reservoir 30 to fill the first hydraulic chamber 111 or the second hydraulic chamber 112. Operation of the first and second dump valves 222 and 232 will be described again below.

The first and second switching valves 221 and 231 and the first and second dump valves 222 and 232 are normally closed but operate normally to open the valve upon receiving an open signal. Solenoid valve is provided.

The inlet valve 204 disposed upstream of the caliper brake 40 to control the transfer of hydraulic pressure to the caliper brake 40 is provided as a normally open solenoid valve. The inlet valve 204 transmits or blocks the hydraulic pressure to the caliper brake 40 by the opening and closing operation, as well as to discharge the hydraulic pressure.

Additionally, the hydraulic control unit 200 may further include an outlet valve (not shown) connected to the reservoir 30 to improve performance when the brake is released. Although not shown, the outlet valve connects the reservoir 30 with at least one wheel RR, RL, FR, FL of the first and second hydraulic circuits 201, 202, and the wheels RR, RL, FR. , FL) controls the escape of the hydraulic pressure. This outlet valve may be provided as a normally closed solenoid valve.

According to an aspect of the present invention, a balance valve 240 is installed between the first and second hydraulic circuits 201 and 202 to control the connection of the two hydraulic circuits 201 and 202. More specifically, the balance valve 240 is disposed downstream of the first and second hydraulic controllers and connected to the respective hydraulic passages 211 and 212. Accordingly, the balance valve 240 transmits the flow of the hydraulic pressure generated from the first and second hydraulic chambers 111 and 112 to the first and second hydraulic circuits 201 and 202 so that the hydraulic circuits 201 and 202 are provided. Hydraulic pressure is supplied to the caliper brake 40 provided in the). The operation structure of the balance valve 240 will be described again below.

The balance valve 240 is normally closed and is provided as a normal closed solenoid valve that operates to open the valve based on the pressure information.

The balance valve 240 is connected to the first and second backup passages 251 and 252 which will be described later.

The first backup passage 251 and the second backup passage 252 form a passage between the master cylinder 20 and the caliper brake 40. That is, the first and second backup passages 251 and 252 serve to transfer the hydraulic pressure generated from the master cylinder 20 to each caliper brake 40 when the electronic brake system fails. More specifically, the first backup passage 251 is provided with a first cut valve 261 for controlling the flow of oil, and the second backup passage 252 is provided with a second cut valve 262 for controlling the flow of oil. Is prepared. In addition, the first backup passage 251 connects the first hydraulic port 24a and the first hydraulic circuit 201, and the second backup passage 252 connects the second hydraulic port 25b and the second hydraulic circuit ( 202). As shown, the first and second backup passages 251 and 252 are connected to both ends of the balance valve 240 connected to the hydraulic passages 211 and 212 of the hydraulic circuits 201 and 202, that is, to the inlet / outlet. do.

On the other hand, the first and second cut valves (261, 262) is provided as a normal open type solenoid valve that is open in the normal state, but operates to close the valve upon receiving a close signal from the electronic control unit. .

In addition, the simulation device 50 is provided to be connected to the master cylinder 20 to provide a reaction force according to the pedaling force of the brake pedal 10. As shown, a flow path connecting the master cylinder 20 and the simulation device 50 is connected to the first backup flow path 251. The simulation apparatus 50 includes a simulation chamber 51 provided to store oil flowing out of the first hydraulic port 24a of the master cylinder 20, a reaction force piston 52 provided in the simulation chamber 51, and A pedal simulator having an elastically supported reaction spring (53) and a simulation valve (54) connected to the rear end of the simulation chamber (51). At this time, the simulation chamber 51 is installed to have a certain range of displacement by the oil flowing into the simulation chamber 51 by the reaction force piston 52 and the reaction force spring 53.

The simulation valve 54 is configured to connect the rear end of the simulation chamber 51 and the reservoir 30. That is, the inlet of the simulation chamber 51 is connected to the master cylinder 20, the rear end of the simulation chamber 51 is connected to the simulation valve 54, the simulation valve 54 is connected to the reservoir 30 as The entire pedal simulator, i.e., the interior of the simulation chamber 51, is filled with oil.

The simulation valve 54 is composed of a normally closed solenoid valve that maintains a normally closed state and is opened when the driver steps on the brake pedal 10 to transmit a braking oil to the simulation chamber 51.

In addition, a simulation check valve 55 is provided between the simulation chamber 51 and the simulation valve 54. The simulation check valve 55 is configured such that oil flows from the reservoir 30 only to the simulation chamber 51. That is, the reaction force piston 52 of the pedal simulator compresses the reaction force spring 53, and oil in the simulation chamber 51 is transmitted to the reservoir 30 through the simulation valve 54. Therefore, since the oil is filled in the simulation chamber 51, the friction of the reaction force piston 52 is minimized when the simulation apparatus 50 is operated, so that the durability of the simulation apparatus 50 is improved, and foreign matters are introduced from the outside. It has a blocked structure.

In addition, as the oil is supplied to the simulation chamber 51 through the simulation check valve 55 when the pedal pedal 10 is released, the quick return of the pedal simulator pressure is ensured.

Meanwhile, reference numeral 'PS1', which is not described, is a first pressure sensor that senses a hydraulic pressure of the first hydraulic circuit 201, and 'PS2' is a second pressure sensor that senses a hydraulic pressure of the second hydraulic circuit 202. , 'PS3' is a third pressure sensor for measuring the oil pressure of the master cylinder 20, 'MCS' is a motor control sensor for controlling the rotation angle of the motor or the current of the motor.

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

2 is a hydraulic circuit diagram showing a state when the electronic brake system operates normally.

Referring to FIG. 2, when braking by the driver is started, the amount of braking required by the driver may be sensed through information such as the pressure of the brake pedal 10 that the driver presses through the pedal displacement sensor 11. The electronic control unit (not shown) receives the electrical signal output from the pedal displacement sensor 11 to drive the motor 140. In addition, the electronic control unit includes a third pressure sensor PS3 provided at the outlet side of the master cylinder 20 and first and second pressure sensors PS1 and PS2 provided at the first and second hydraulic circuits 201 and 202. The amount of regenerative braking amount can be input through the controller, and the amount of friction braking amount can be calculated according to the difference between the required braking amount and the regenerative braking amount of the driver. Can be.

Specifically, when the driver presses the brake pedal 10 at the beginning of braking, the motor 140 operates, and the rotational force of the motor 140 is converted into a linear motion so that the double-acting piston 120 moves forward and the second hydraulic chamber 112 ) Pressurizes to generate a hydraulic pressure. At this time, the first and second cut valves 261 and 262 installed in the first and second backup passages 251 and 252 connected to the first and second hydraulic ports 24a and 24b of the master cylinder 20 are closed. Therefore, the hydraulic pressure generated in the master cylinder 20 is not transmitted to the caliper brake 40.

In addition, the hydraulic pressure generated from the second pressure chamber 112 is transmitted to each caliper brake 40 as the second switching valve 231 and the balance valve 240 are opened to generate a braking force.

In addition, the second dump valve 232 is controlled to maintain the closed state so that the hydraulic pressure generated from the second hydraulic chamber 112 is transmitted to the caliper brake 40 without loss. At this time, the area in the first hydraulic chamber 111 is increased by the advancing of the double-acting piston 120, so that the first dump valve 222 is opened to suck oil from the reservoir 30, so that the first hydraulic chamber 111 is opened. Will be filled with.

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

Next, a case of releasing the braking force in the braked state in the normal operation of the electronic brake system as described above will be described with reference to FIG. 3. As shown in FIG. 3, when the pedal force applied to the brake pedal 10 is released, the motor 140 generates a rotational force in a direction opposite to the direction in which the double-acting piston 120 is advanced so that the double-acting piston 120 returns to its original position. Is returned. At this time, each of the valves 54, 204, 221, 222, 231, 232, 240, 261, and 262 for controlling the flow of hydraulic pressure maintains the same opening / closing state as in the braking operation, thereby allowing oil into the second hydraulic chamber 112. Will be filled. That is, the hydraulic pressure discharged from the caliper brake 40 of the first hydraulic circuit 201 is the second hydraulic flow path together with the hydraulic pressure discharged from the caliper brake 40 of the second hydraulic circuit 202 through the balance valve 240. It is delivered to 212 and flows into the second hydraulic chamber 112. In addition, the oil of the first hydraulic chamber 111 pressurized as the double-acting piston 120 is retracted is transferred to the reservoir 30 through the first dump valve 222 and stored.

The simulation device 50 ensures a quick return of the pedal simulator pressure by filling the oil back into the simulation chamber 51 through the simulation check valve 55.

On the other hand, the electronic brake system according to an embodiment of the present invention is a hydraulic control unit according to the required pressure of the caliper brake 40 provided in each of the wheels RR, RL, FR, FL of the two hydraulic circuits (201, 202) The control range may be specified and controlled by controlling the valves 204, 221, 222, 231, 232, and 240 provided at 200. For example, FIGS. 4 and 5 brake the wheel FL of one of the two wheels RR, FL of the second hydraulic circuit 202 during ABS operation, and then again the other of the same hydraulic circuit 202. The state of braking the wheel RR is shown.

First, referring to FIG. 4, the motor 140 operates according to the stepping force of the brake pedal 10, and the rotational force of the motor 140 is converted into a linear motion so that the double acting piston 120 moves forward to the second hydraulic chamber ( The hydraulic pressure is generated by pressing 112). At this time, the first and second cut valves 261 and 262 are closed so that the hydraulic pressure generated in the master cylinder 20 is not transmitted to the caliper brake 40. Further, the inlet valve 204 provided upstream of the right rear wheel RR of the first switching valve 221, the second dump valve 232, the balance valve 240, and the second hydraulic circuit 202 is closed. . Accordingly, the hydraulic pressure generated from the second hydraulic chamber 112 is transmitted to the second hydraulic circuit 202 through the second switching valve 231, but only to the left front wheel FL of the two wheels RR and FL. Hydraulic pressure is delivered. At this time, the first dump valve 222 is opened to suck oil from the reservoir 30 to be delivered to the first hydraulic chamber 111.

Next, as shown in Figure 5, according to the rotational force of the motor 140, the double-acting piston 120 is converted to a linear motion to retreat to press the first hydraulic chamber 111 to generate a hydraulic pressure.

At this time, the first and second cut valves 261 and 262 are closed so that the hydraulic pressure generated in the master cylinder 20 is not transmitted to the caliper brake 40. In addition, the first dump valve 222 and the second switching valve 231 are closed, except for the inlet valve 204 provided upstream of the right rear wheel RR of each of the wheels RR, RL, FR, and FL. The remaining inlet valve 204 is closed. Thus, the hydraulic pressure generated from the first hydraulic chamber 111 is transmitted to the second hydraulic circuit 202 through the first switching valve 221 and the balance valve 240, the right of the two wheels (RR, FL) The hydraulic pressure is transmitted only to the rear wheels RR. At this time, the second dump valve 232 is opened to suck oil from the reservoir 30 to be transferred to the second hydraulic chamber 112.

In the electronic brake system according to the present invention, as the hydraulic pressure supply device 100 is double-acting, the wheels RR, RL, FR, which generate hydraulic pressure even when the double-acting piston 120 is retracted as described above are required. To FL). That is, compared with the conventional single-acting piston structure, the pressure can be quickly regenerated and boosted, thereby improving the responsiveness.

The case where the electronic brake system does not operate normally will be described. Referring to FIG. 6, when the electronic brake system does not operate normally, each of the valves 54, 204, 221, 222, 231, 232, 240, 261, and 262 is provided in an initial braking state in an inoperative state. Accordingly, when the driver presses the brake pedal 10, the input rod 12 connected to the brake pedal 10 moves to the left side, and at the same time, the first piston 21a and the first piston which are in contact with the input rod 12. By 21a, the second piston 22a is also advanced to the left. At this time, since there is no gap between the input rod 12 and the first piston 21a, braking can be performed quickly. That is, the hydraulic pressure generated by pressurizing the master cylinder 20 is transmitted to the caliper brake 40 through the first and second backup passages 251 and 252 connected for backup braking to implement the braking force. At this time, the first and second cut valves 261 and 262 provided in the first and second backup passages 251 and 252 and the inlet valve 204 provided upstream of each of the wheels RR, RL, FR, and FL. Is composed of a normally open solenoid valve, the simulation valve 54, the first and second switching valves (221, 231), the first and second dump valves (222, 232), and the balance valve 240 As the normally closed solenoid valve is configured, the hydraulic pressure is directly transmitted to the caliper brake 40. This makes it possible to perform a stable braking it is possible to improve the braking stability.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

10: brake pedal 11: pedal displacement sensor
20: master cylinder 30: reservoir
40: caliper brake 50: simulation device
54: simulation valve 100: hydraulic pressure supply device
110: hydraulic cylinder 111: first hydraulic chamber
112: second hydraulic chamber 120: double acting piston
130: power conversion unit 140: motor
200: hydraulic control unit 201: first hydraulic circuit
202: second hydraulic circuit 211: first hydraulic flow path
212: 2nd hydraulic flow path 221: 1st switching valve
222: the first dump valve 231: the second switching valve
232: second dump valve 240: balance valve
251: first backup euro 252: second backup euro
261: first cut valve 262: second cut valve

Claims (11)

A reservoir having oil stored therein, first and second hydraulic ports and a master cylinder coupled to the reservoir to receive oil, a pedal displacement sensor for detecting displacement of the brake pedal coupled to the master cylinder, and connected to the master cylinder In the electronic brake system including a simulation device is provided to provide a reaction force according to the pedal force of the brake pedal,
A hydraulic pressure supply device for outputting an electric signal through a pedal displacement sensor when the brake pedal is operated to convert the rotational force of the motor into a linear motion to move a double-acting piston;
A hydraulic control unit having first and second hydraulic circuits for receiving a hydraulic pressure by a force generated by the hydraulic pressure supply device and controlling a flow of hydraulic pressure delivered to caliper brakes provided at each wheel;
First and second cut valves provided in first and second backup passages connecting the first and second hydraulic ports and the first and second hydraulic circuits to control the flow of hydraulic pressure; And
And an electronic control unit that controls the motor and the valves based on the hydraulic pressure information and the pedal displacement information.
A first hydraulic chamber and a second hydraulic chamber are provided at both sides of the double-acting piston,
And the double acting piston advances to generate a hydraulic pressure of the second hydraulic chamber, and the double acting piston retreats to generate a hydraulic pressure of the first hydraulic chamber. The method of claim 1,
The hydraulic pressure supply device,
A motor generating a rotational force by an electrical signal of the pedal displacement sensor;
A power converter converting the rotational motion of the motor into a linear motion;
A double-acting piston connected to the power converter and linearly moving; And
And a hydraulic cylinder provided with the double acting piston slidably and having a first and a second hydraulic chamber with the double acting piston interposed therebetween. The method of claim 1,
And the first hydraulic chamber is connected to the first hydraulic circuit by a first hydraulic passage, and the second hydraulic chamber is connected to the second hydraulic circuit by a second hydraulic passage. The method of claim 3,
The hydraulic control unit,
A first hydraulic controller provided in the first hydraulic passage to control the flow of the hydraulic pressure;
A second hydraulic controller provided in the second hydraulic passage to control the flow of the hydraulic pressure; And
And a normally open inlet valve disposed at an upstream side of the caliper brake to control the transfer of hydraulic pressure to the caliper brake. The method of claim 4, wherein
The first hydraulic control unit includes a first switching valve provided in the first hydraulic flow path, and a first dump valve provided in a flow path connecting the first hydraulic flow path and the reservoir,
And the second hydraulic control unit includes a second switching valve provided in the second hydraulic flow path, and a second dump valve provided in a flow path connecting the second hydraulic flow path and the reservoir. The method of claim 5,
The first and second dump valves are connected to the first and second hydraulic chambers, respectively, to be opened or closed in the direction of the forward and backward movement of the double acting piston, and the oil is sucked from the reservoir to the first hydraulic chamber or the second hydraulic pressure. Electronic brake system, characterized by filling the chamber. The method of claim 5,
And the first and second switching valves and the first and second dump valves are normally closed solenoid valves which are normally closed and operate to open the valve upon receiving an open signal. The method of claim 4, wherein
An electronic brake further comprising a balance valve disposed downstream of the first and second hydraulic controllers between the first and second hydraulic passages and connecting and disconnecting the first and second hydraulic circuits. system. The method of claim 8,
And the balance valve is connected to the first and second backup passages. The method of claim 8,
The balance valve is an electronic brake system, characterized in that the normally closed solenoid valve which is normally closed but operates to open the valve upon receiving an open signal. The method of claim 1,
And the first and second cut valves are normally open solenoid valves that are open in a normal state and operate to close the valves upon receiving a closing signal from the electronic control unit.

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