JP2007186173A - Brake system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular brake system comprising an electric parking brake device and a service brake device which is capable of generating a braking force by using the electric parking brake device even if a brake actuator of a service brake is failed. <P>SOLUTION: The brake system 10 comprises an electric parking brake device 72 for applying or releasing a parking brake by a motor, and a service brake device 78 for generating the braking force according to the operation of a brake operation means by a driver. A brake actuator 18 controls the hydraulic pressure of a wheel cylinder 24 based on the operation of the brake operation means by the driver. A hydraulic pressure generation mechanism 20 controls the hydraulic pressure of the wheel cylinder 24 by using the energy accumulated by using the motor. A solenoid valve 22 changes the liquid passage of a working fluid to the wheel cylinder from the brake actuator 18 to the hydraulic pressure generation mechanism 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brake system, and in particular, for a vehicle including an electric parking brake device that operates or releases a parking brake with a motor, and a service brake device that generates a braking force in response to an operation of a brake operation means by a driver. It relates to the brake system.

In general, a vehicle such as an automobile is equipped with a parking brake in addition to a service brake that generates a braking force in accordance with a depression amount of a brake pedal by a driver. The simplest type of parking brake is to drive a wire by pulling an operation lever to operate a brake pad and brake a wheel. However, in recent years, an electric parking brake (EPB) device that drives or releases an electric motor by switching an operation switch or the like by a driver is also employed. In this electric parking brake device, when the driver sets the operation switch to the operating side, the electric motor is driven and the wire is caught to operate the parking brake, and when the operation switch is set to the release side, the wire is rewound. The parking brake is released (see, for example, Patent Document 1).
JP 2001-106057 A

  By the way, in the vehicle brake system, it is conceivable to provide an actuator different from the brake actuator used during normal operation as a countermeasure when the brake actuator of the service brake fails. However, when a plurality of actuators are provided in this way, there is a problem that the configuration of the apparatus becomes complicated, resulting in an increase in cost and an increase in the size of the apparatus.

  The present invention has been made in view of such circumstances, and the object thereof is a vehicle brake system including an electric parking brake device and a service brake device, even when the brake actuator of the service brake has failed. Another object of the present invention is to provide a brake system capable of generating a braking force using an electric parking brake device.

  In order to solve the above problems, a brake system according to an aspect of the present invention generates an electric parking brake device that activates or releases a parking brake with a motor, and generates a braking force in response to an operation of a brake operation unit by a driver. A brake system for a vehicle including a service brake device, wherein the service brake device is configured to reduce a hydraulic pressure of a wheel cylinder that is provided on a vehicle wheel and exerts a braking force based on an operation of a brake operation unit by a driver. Failure occurs in the first hydraulic pressure control means for controlling, the second hydraulic pressure control means for controlling the hydraulic pressure of the wheel cylinder using the energy stored by the motor, and the first hydraulic pressure control means. In this case, a fluid path switching unit that switches the fluid path of the working fluid to the wheel cylinder from the first fluid pressure control unit to the second fluid pressure control unit is provided.

  According to this aspect, even if a failure occurs in the first hydraulic pressure control means, the hydraulic pressure is transmitted to the wheel cylinder by using the energy stored in the second hydraulic pressure control means, and the braking force Can be generated. This energy accumulation is performed using a motor that operates or releases the electric parking brake device, so that it is not necessary to prepare a separate driving force source for operating the brake, and the number of parts can be reduced.

  The second hydraulic pressure control means includes a cylinder that communicates with the liquid path switching means, a liquid that is inserted into the cylinder, slides within the cylinder in accordance with the rotation of the motor, and the cylinder is filled with the pressing chamber and the working fluid. A piston defined in the pressure generating chamber, an elastic member provided in the pressing chamber and storing elastic energy by rotating the motor when the first hydraulic pressure control means is in a non-defective state, and the first hydraulic pressure control And energy release means for generating hydraulic pressure in the hydraulic pressure generating chamber by releasing elastic energy stored in the elastic member when a failure occurs in the means. By configuring the second hydraulic pressure control means in such a configuration, it is possible to generate a hydraulic pressure that stores energy using a motor and transmits the energy to the wheel cylinder.

  The second hydraulic pressure control means is defined and pressurized by a cylinder communicating with the liquid path switching means, a piston inserted in the cylinder and sliding in the cylinder according to the rotation of the motor, and the piston. The hydraulic pressure of the working fluid enclosed inside may be increased, and a hydraulic pressure generating chamber for storing pressure energy may be provided. When the fluid path of the working fluid to the wheel cylinder is switched from the first hydraulic pressure control means to the second hydraulic pressure control means in the state where the hydraulic pressure in the hydraulic pressure generation chamber is increased, the hydraulic pressure generation chamber operates from the hydraulic pressure generation chamber to the wheel cylinder. The fluid is sent out and the hydraulic pressure in the wheel cylinder can be increased.

  The second hydraulic pressure control means may be configured to activate the parking brake when the motor is rotated in one direction and store energy when the motor is rotated in the other direction. With this configuration, the parking brake can be actuated or released and energy can be stored with a single motor.

  According to the present invention, in a vehicle brake system including an electric parking brake device and a service brake device, even if the brake actuator of the service brake has failed, the electric parking brake device is used to generate a braking force. Can be generated.

  FIG. 1 is a diagram showing a configuration of a brake system 10 according to an embodiment of the present invention. The brake system 10 is installed in a vehicle, and includes a service brake device 78 that decelerates and stops when the vehicle travels, and an electric parking brake device (hereinafter referred to as EPB: Electric Parking Break) that mainly maintains the stopped state of the vehicle. 72).

  The service brake device 78 includes a brake pedal 12, a stroke sensor 14, an ECU 16, a brake actuator 18, a hydraulic pressure generation mechanism 20, an electromagnetic valve 22, and a wheel cylinder 24.

  When the brake pedal 12 is depressed by the driver, the stroke sensor 14 detects a stroke amount signal corresponding to the amount of depression. The detected stroke amount signal is transmitted to the ECU 16. The ECU 16 calculates a target deceleration of the vehicle from the input stroke amount signal, and calculates a command value to be given to the brake actuator 18 so as to approach the calculated target deceleration.

  The wheel cylinder 24 is one of the components constituting the disc brake device provided on the wheel, and by increasing the hydraulic pressure of the wheel cylinder 24, the brake pad is pressed against the disc and the braking force is exerted.

  The brake actuator 18 has a function of controlling the hydraulic pressure of the wheel cylinder 24 based on a command value from the ECU 16. The brake actuator 18 includes a master cylinder, an accumulator, various control valves, and the like (not shown), and has a well-known configuration for controlling the hydraulic pressure of the wheel cylinder. An electromagnetic valve 22 that is actuated by a command from the ECU 16 is disposed in the middle of the fluid path that connects the brake actuator 18 and the wheel cylinder 24.

  In the present embodiment, a hydraulic pressure generation mechanism 20 is provided in case the brake actuator 18 fails for some reason. Although the detailed structure will be described later, the hydraulic pressure generating mechanism 20 is used for operating or releasing the electric parking brake device 72 when the brake actuator 18 is operating normally (hereinafter referred to as a normal state). Energy is stored using a motor. When the brake actuator 18 is in a state of failure (hereinafter referred to as a failure state), hydraulic pressure is generated in the working fluid by using the stored energy. The hydraulic pressure generation mechanism 20 is connected to the electromagnetic valve 22 via the second liquid path 28.

  The electromagnetic valve 22 switches the fluid path of the working fluid to the wheel cylinder 24 from the brake actuator 18 to the hydraulic pressure generating mechanism 20 when a failure occurs in the brake actuator 18. The electromagnetic valve 22 switches the liquid path according to a command from the ECU 16. In the normal state, the first liquid passage 26 connected to the brake actuator 18 and the wheel cylinder side liquid passage 23 are in communication with each other. Therefore, in a normal state, the hydraulic pressure generated in the brake actuator 18 is transmitted to the wheel cylinder 24 via the first fluid path 26, the electromagnetic valve 22, and the wheel cylinder side fluid path 23, and the braking force is exhibited. . Although only one wheel cylinder 24 is shown in FIG. 1 for convenience, it is preferable to dispose wheel cylinders on at least the left and right front wheels of the vehicle.

  On the other hand, when the brake actuator 18 is in a failure state, the electromagnetic valve 22 is actuated by a command from the ECU 16 and the communication between the brake actuator 18 and the wheel cylinder 24 is cut off. Instead, the hydraulic pressure generating mechanism 20 and the wheel cylinder 24 Will be in communication. Therefore, in the failure state, the hydraulic pressure generated in the hydraulic pressure generating mechanism 20 is transmitted to the wheel cylinder 24 via the second fluid passage 28, the electromagnetic valve 22, and the wheel cylinder side fluid passage 23, and the braking force is increased. Demonstrated.

  Next, the electric parking brake device 72 will be described. As shown in FIG. 1, in the electric parking brake device 72, the wire 35 extending from the hydraulic pressure generating mechanism 20 is connected to the rear wheel brake device 76 provided on the rear wheel of the vehicle via the hoisting device 62. It has a configuration. As will be described later, the wire 35 is configured to be wound or unwound using the motor of the hydraulic pressure generation mechanism 20 as a driving force source. The rear wheel brake device 76 is, for example, a drum brake.

  The driver can select the operation or release of the electric parking brake device 72 by operating the EPB switch 70 disposed near the front panel of the driver's seat or the shift lever in the passenger compartment of the vehicle. When the driver selects the operation of the electric parking brake device 72, the ECU 16 instructs the motor of the hydraulic pressure generation mechanism 20 to wind up the wire 35. When the motor of the hydraulic pressure generating mechanism 20 is driven to wind up the wire 35, the wire 74 is also wound up at the same time, and the rear wheel brake device 76 is operated to generate a braking force on the rear wheel. When the driver selects to release the electric parking brake device 72, the ECU 16 issues a command to rewind the wire 35 to the motor of the hydraulic pressure generation mechanism 20. When the motor of the hydraulic pressure generating mechanism 20 is driven in the reverse rotation direction and the wire 35 is rewound, the rear wheel brake device 76 is released to enter a non-braking state.

  Even after the operation of the motor of the hydraulic pressure generating mechanism 20 is stopped, in order to maintain the state of the wound wire 35, that is, the braking state of the rear wheel brake device 76 after the wire 35 is stopped in the wound state is maintained. For this purpose, the hydraulic pressure generating mechanism 20 is provided with a lock mechanism. This locking mechanism will be described later.

  FIG. 2 is a diagram illustrating the configuration of the hydraulic pressure generation mechanism 20. As shown in FIG. 2, the hydraulic pressure generation mechanism 20 includes a motor 30, a parking brake drive device 31, a power transmission device 52, and a hydraulic pressure generation device 60. The hydraulic pressure generating mechanism 20 is characterized in that the parking brake driving device 31 and the hydraulic pressure generating device 60 can be driven by a single motor 30.

  The motor 30 is a motor that can operate in both forward and reverse directions. The parking brake drive device 31 includes a lock mechanism 88, a ball screw 32, a parking brake equalizer 34, a ball bush 86, and a wire 35. The screw shaft of the ball screw 32 is connected to the shaft of the motor 30, and when the motor 30 rotates, the ball screw 32 also rotates. The ball screw 32 is provided with a ball bush 86, which moves in the left-right direction in the figure when the ball screw 32 rotates. A lock mechanism 88 is provided between the motor 30 and the ball screw 32. The lock mechanism 88 is a mechanical clutch mechanism that is unlocked when torque is applied. The lock mechanism 88 can prevent the electric parking brake device 72 from being released even when the motor 30 is not operating. A wire 35 is connected to the parking brake equalizer 34. The parking brake equalizer 34 is provided so as to slide along the ball screw 32. Although omitted in FIG. 2, the other end of the wire 35 is connected to the rear wheel brake device 76 shown in FIG. When the motor 30 is rotated by a command from the ECU 16, the ball bush 86 moves on the ball screw 32 and pushes the parking brake equalizer 34, whereby the wire 35 is wound up and the electric parking brake device 72 can be operated.

  The power transmission device 52 has a function of transmitting power generated by the rotation of the motor 30 to the hydraulic pressure generation device 60, and includes a worm wheel 36, a clutch 38, and a pinion gear 40. The worm wheel 36 is configured to rotate with the rotation of the worm formed at the tip of the screw shaft of the ball screw 32, and transmits the rotation of the motor 30 to the pinion gear 40. Actually, a plurality of gears are included between the worm wheel 36 and the pinion gear 40, but are omitted in FIG. 2 for convenience of explanation. A clutch 38 is provided between the worm wheel 36 and the pinion gear 40 to intermittently transmit the rotational motion of the motor. When the clutch 38 is in the closed state, the rotation of the motor 30 is transmitted to the pinion gear 40 via the ball screw 32 and the worm wheel 36. However, when the clutch 38 is in the open state, the rotation of the motor 30 is transmitted to the pinion gear 40. Not transmitted, the pinion gear 40 does not rotate.

  The hydraulic pressure generator 60 has a function of storing energy due to the rotational motion of the motor 30 and generating hydraulic pressure using the energy. The rack 42 is formed with a rack gear at a position where it engages with the pinion gear 40, and constitutes a pinion gear 40 and a rack and pinion. Therefore, the rack 42 can be moved in the left-right direction in the figure by the rotation of the pinion gear 40.

  The other end of the rack 42 is inserted into a cylinder 48 that communicates with the electromagnetic valve 22, and slides within the cylinder 48 in accordance with the rotation of the motor 30, so that the cylinder 48 is divided into a pressing chamber 49 and a fluid pressure generating chamber 50. It is connected to the formed piston 46. The hydraulic pressure generation chamber 50 is connected to a reserve tank 82 containing a working fluid via a check valve 84, and is configured so that the working fluid is supplied from the reserve tank 82. The reserve tank 82 may be used in the brake actuator 18 shown in FIG. The check valve 84 prevents the working fluid from flowing back from the hydraulic pressure generation chamber 50 to the reserve tank 82.

  The pressing chamber 49 is provided with an elastic member 44 such as a spring. The elastic member 44 is provided so as to bias the piston 46 toward the hydraulic pressure generation chamber 50. When the piston 46 is moved in the direction of the pressing chamber 49 by rotating the motor 30, the elastic member 44 contracts and elastic energy is stored.

  The operation of the hydraulic pressure generating mechanism 20 configured as described above will be described. FIG. 3 shows the operation of the hydraulic pressure generating mechanism 20 when the electric parking brake device 72 is operated. When the driver operates the EPB switch 70 to the operating side, a command is issued from the ECU 16 to the motor 30, and the motor 30 rotates by a predetermined rotation amount. The rotation direction of the motor 30 at this time is defined as a positive direction. The screw shaft of the ball screw 32 is rotated by the rotation of the motor 30, and the parking brake equalizer 34 is moved to the left in the drawing from the position of the origin by being pushed by the ball bush 86. As a result, the wire 35 is wound up, the electric parking brake device 72 is operated, and the braking force is exerted.

  When the electric parking brake device 72 is operated, the clutch 38 is set to be in an open state by a command from the ECU 16. Therefore, the rotational motion of the motor 30 is not transmitted to the pinion gear 40, and the position of the piston 46 does not fluctuate.

  FIG. 4 shows the operation of the hydraulic pressure generating mechanism 20 when the electric parking brake device 72 is released. When the driver operates the EPB switch 70 to the release side, a command is issued from the ECU 16 to the motor 30, and the motor 30 rotates by a predetermined rotation amount. The rotation direction at this time is a negative direction opposite to the positive direction. As the motor 30 rotates in the negative direction, the ball bushing 86 moves to the right in the figure. Since the parking brake equalizer 34 receives a leftward tension by the wire 35, the parking brake equalizer 34 moves to the right according to the movement of the ball bush 86. The parking brake equalizer 34 is configured not to move rightward from the origin by a stopper member (not shown) provided at the origin. As a result, the wire 35 is rewound and the electric parking brake device 72 is released.

  In the operation of releasing the electric parking brake device 72, the clutch 38 is set to be in a closed state by a command from the ECU 16. Accordingly, the rotational motion of the motor 30 is transmitted to the pinion gear 40 via the ball screw 32, the worm wheel 36, and the clutch 38. In the present embodiment, due to the gear configuration of the power transmission device 52, when the motor 30 rotates in the negative direction, the pinion gear 40 rotates clockwise. When the pinion gear 40 rotates clockwise, the rack 42 moves to the left. As a result, the piston 46 moves leftward within the cylinder 48, and the elastic member 44 contracts to store elastic energy. Even if the clutch 38 is opened in this state, the fluid path from the fluid pressure generating chamber 50 to the reserve tank 82 is blocked by the check valve 84, and the fluid path from the fluid pressure generating chamber 50 to the wheel cylinder 24 is Since it is interrupted | blocked by the electromagnetic valve 22, the piston 46 cannot move rightward in the figure, and the elastic energy stored in the elastic member 44 is maintained. Thus, in the hydraulic pressure generating mechanism 20 according to the present embodiment, the electric parking brake device 72 is operated when the motor 30 is rotated in the positive direction, and elastic energy is applied to the elastic member 44 when the motor 30 is rotated in the negative direction. Can be stored.

  FIG. 5 shows the operation of the hydraulic pressure generating mechanism 20 when the brake actuator 18 fails. When a failure occurs in the brake actuator 18, the clutch 38 is opened according to a command from the ECU 16. Further, at this time, as described above, the electromagnetic valve 22 is actuated by a command from the ECU 16, the communication between the brake actuator 18 and the wheel cylinder 24 is cut off, and instead the fluid pressure generating mechanism 20 and the wheel cylinder 24 are in communication. . As a result, the elastic energy stored in the elastic member 44 is released, and the piston 46 is pushed rightward in the drawing, so that hydraulic pressure is generated in the working fluid in the hydraulic pressure generating chamber 50. The generated hydraulic pressure is transmitted to the wheel cylinder 24 via the second liquid path 28, the electromagnetic valve 22, and the wheel cylinder side liquid path 23. As a result, the brake pad is pressed against the disc and the braking force is exerted.

  As described above, according to the present embodiment, even when the brake actuator 18 has failed, the hydraulic pressure is applied to the wheel cylinder 24 by using the elastic energy stored in the hydraulic pressure generating mechanism 20. It can transmit and exert braking force. Since the elastic energy can be accumulated using the motor 30 that operates or releases the electric parking brake device 72, it is not necessary to prepare a separate driving force source such as a motor, and the number of components can be reduced. . Further, since energy can be stored while the electric parking brake device 72 is operated or released in a normal state where no failure has occurred in the brake actuator 18, energy can be stored after the brake actuator 18 has failed. The braking force can be exerted more quickly than when storing.

  FIG. 6 shows a modification of the hydraulic pressure generating mechanism. In the hydraulic pressure generating mechanism 20 shown in FIG. 2, an elastic member 44 is provided in the pressing chamber 49 of the cylinder 48 so that elastic energy can be stored. The hydraulic pressure generating mechanism 80 shown in FIG. 6 is different from the hydraulic pressure generating mechanism 20 shown in FIG. 2 in that no elastic member is provided in the pressing chamber 49. In the hydraulic pressure generation mechanism 80, pressure energy is stored by pressurizing the hydraulic pressure generation chamber 50 in which the working fluid is sealed with the piston 46, and the hydraulic pressure is transmitted to the wheel cylinder 24 using this pressure energy.

  In the hydraulic pressure generating mechanism 80, the gear of the power transmission device 52 is configured so that the pinion gear 40 rotates counterclockwise when the motor 30 rotates in the negative direction. When the pinion gear 40 rotates counterclockwise, the piston 46 moves in the direction in which the hydraulic pressure generating chamber 50 is pressurized, that is, in the right direction in the figure.

  In the hydraulic pressure generating mechanism 80, the piston 46 is pushed toward the pressing chamber 49 by the hydraulic pressure in the hydraulic pressure generating chamber 50, so that the piston 46 is prevented from moving toward the pressing chamber 49 when the motor 30 is not operating. Therefore, a lock mechanism including a lock pin 54 and a solenoid 56 is provided. This locking mechanism is formed so that the inclined surface 54a of the lock pin 54 is engaged with a sawtooth-shaped inclined surface 42a formed in a part of the rack 42. The lock pin 54 is biased in a direction to engage with the sawtooth of the rack 42. Further, the solenoid 56 can be moved in a direction in which the lock pin 54 is separated from the rack 42 by a signal from the ECU 16. By this lock mechanism, the timing at which the elastic energy stored in the elastic member 44 is released can be controlled.

  The operation of the hydraulic pressure generating mechanism 80 will be described. When the electric parking brake device 72 is operated by rotating the motor 30 in the forward direction, the clutch 38 is opened as described with reference to FIG. Therefore, at this time, the piston 46 does not move. When the motor 30 is rotated in the negative direction and the electric parking brake device 72 is released, the clutch 38 is closed. When the motor 30 rotates in the negative direction with the clutch 38 in the closed state, the piston 46 moves in a direction in which the hydraulic pressure generating chamber 50 is pressurized, and pressure energy is stored in the hydraulic pressure generating chamber 50.

  When a failure occurs in the brake actuator 18 and the fluid path of the working fluid to the wheel cylinder 24 is switched from the brake actuator 18 to the hydraulic pressure generating mechanism 80, the hydraulic fluid is increased in the hydraulic pressure generating chamber 50 by the hydraulic pressure. It is sent out to the cylinder 24. As a result, the hydraulic pressure of the wheel cylinder 24 is increased and the braking force is exhibited. In the case of this modification, the elastic member is not necessary, and therefore the number of parts can be reduced. Further, since it is not necessary to unlock the piston 46 when the brake actuator 18 fails, the processing of the ECU 16 can be simplified.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

  For example, in the above embodiment, the brake pedal is described as an example of the service brake operation means. However, the operation means of the present invention is not limited to this, and an operation capable of operating the braking force of the vehicle by tilting the lever. It may be a means.

  In FIG. 1, it is good also as a structure which provides the clutch mechanism using a solenoid between the stroke sensor 14 and ECU16, and connects the clutch mechanism and the hydraulic pressure control valve of a wheel cylinder by a link. The clutch mechanism is opened by a command from the ECU 16 when normal, and is closed by a command from the ECU 16 when the brake actuator 18 fails. In the closed state, the hydraulic pressure of the wheel cylinder 24 can be directly controlled by operating the brake pedal 12 via a link. When the hydraulic pressure of the wheel cylinder 24 is directly controlled by the operation of the brake pedal 12, a large force is required for the operation of the brake pedal 12. However, by providing the hydraulic pressure generating mechanism 20, the hydraulic pressure is added and the failure occurs. Sometimes it is possible to generate a braking force without applying a large force.

It is a figure showing composition of a brake system concerning an embodiment of the invention. It is a figure shown about the structure of a hydraulic pressure generation mechanism. An operation of the hydraulic pressure generating mechanism when the electric parking brake device is operated will be described. The operation of the hydraulic pressure generating mechanism when the electric parking brake device is released will be described. The operation of the hydraulic pressure generating mechanism when the brake actuator fails will be described. It is a figure which shows the modification of a hydraulic pressure generation mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Brake system, 12 Brake pedal, 14 Stroke sensor, 16 ECU, 18 Brake actuator, 20 Fluid pressure generating mechanism, 22 Solenoid valve, 23 Wheel cylinder side fluid path, 24 Wheel cylinder, 26 1st fluid path, 28 2nd fluid Road, 30 motor, 31 parking brake drive device, 32 ball screw, 34 parking brake equalizer, 35 wire, 36 worm wheel, 38 clutch, 40 pinion gear, 42 rack, 42a slope, 44 elastic member, 46 piston, 48 cylinder, 49 pressure chamber, 50 hydraulic pressure generating chamber, 52 power transmission device, 54 lock pin, 54a slope, 56 solenoid, 60 hydraulic pressure generating device, 62 hoisting device, 70 EPB switch, 72 electric Car brake system, 76 rear wheel brake device, 78 service brake device, 80 fluid pressure generating mechanism, 82 reserve tank, 84 check valve, 86 a ball bushing, 88 locking mechanism.

Claims (4)

A vehicle brake system comprising: an electric parking brake device that activates or releases a parking brake with a motor; and a service brake device that generates a braking force in response to an operation of a brake operation means by a driver,
The service brake device is:
First hydraulic pressure control means for controlling the hydraulic pressure of a wheel cylinder that is provided on a wheel of a vehicle and exerts a braking force based on an operation of the brake operation means by a driver;
Second fluid pressure control means for controlling the fluid pressure of the wheel cylinder using the energy stored using the motor;
Fluid path switching means for switching the fluid path of the working fluid to the wheel cylinder from the first fluid pressure control means to the second fluid pressure control means when a failure occurs in the first fluid pressure control means; ,
A brake system comprising: The second hydraulic pressure control means includes
A cylinder communicating with the liquid path switching means;
A piston inserted into the cylinder, sliding in the cylinder in response to rotation of the motor, and defining the cylinder into a pressure chamber and a hydraulic pressure generation chamber in which a working fluid is sealed;
An elastic member that is provided in the pressing chamber and stores elastic energy by rotating the motor when the first hydraulic pressure control means is in a non-failed state;
Energy release means for generating hydraulic pressure in the hydraulic pressure generation chamber by releasing elastic energy stored in the elastic member when a failure occurs in the first hydraulic pressure control means;
The brake system according to claim 1, further comprising: The second hydraulic pressure control means includes
A cylinder communicating with the liquid path switching means;
A piston inserted into the cylinder and sliding in the cylinder in response to rotation of the motor;
A hydraulic pressure generating chamber that is defined by the piston and is pressurized to increase the hydraulic pressure of the working fluid enclosed therein, and stores pressure energy;
The brake system according to claim 1, further comprising:   2. The second hydraulic pressure control unit is configured to operate the parking brake when the motor is rotated in one direction and store energy when the motor is rotated in the other direction. 4. The brake system according to any one of 3.

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