Brake system

Abstract

To provide a brake device enabling improvement of an operation feeling of a brake pedal.SOLUTION: A brake device braking a vehicular wheel comprises: a brake pedal 10; a pedal operation detecting unit 20 that detects an amount of operation of the brake pedal; a tank portion 50 storing brake fluid; an actuator 51 that pressurizes the brake fluid stored in the tank portion, to a brake fluid pressure corresponding to the amount of operation of the brake pedal; a master cylinder 30 having a cylinder portion 31 forming a storage chamber 311 storing the brake fluid, and a piston rod connected to the brake pedal and pushing out the brake fluid stored in the storage chamber thereby discharging the brake fluid to the outside of the cylinder portion; a brake fluid flow channel 40 that guides the brake fluid discharged from the storage chamber to the tank portion; and a reaction force generating unit 80 connected to the brake pedal and having an elastic member 82 that elastically deforms according to the amount of operation of the brake pedal to cause the brake pedal to generate reaction force.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to braking systems. [Background technology]

[0002] Conventionally, a brake device is known that includes a brake pedal, a master cylinder, a stroke simulator corresponding to a reaction force generating unit, a simulator cut valve, a master cut valve, and a brake actuator (see, for example, Patent Document 1). In the brake device described in Patent Document 1, during normal use, the master cut valve is closed and the simulator cut valve is open, and brake fluid, which is a working fluid pressurized from the master cylinder, flows into the stroke simulator when the brake pedal is depressed. In response to this, the stroke simulator generates a reaction force on the brake pedal via the master cylinder that corresponds to the hydraulic pressure of the brake fluid that flows in from the master cylinder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-30543 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, in the brake device described in Patent Document 1, during normal use, the stroke simulator is activated by brake fluid sent from the master cylinder. In other words, because brake fluid is present between the brake pedal and the reaction force generating part, there is room for improvement in the operating feel of the brake pedal.

[0005] An object of the present disclosure is to provide a brake device that can improve the operation feel of the brake pedal. [Means for solving the problem]

[0006] The invention described in claim 1 is A braking device for braking a wheel of a vehicle, A brake pedal (10), a pedal operation detection unit (20) that detects an operation amount of a brake pedal; a tank portion (50) for storing brake fluid; an actuator (51) for pressurizing the brake fluid stored in the tank to a brake fluid pressure corresponding to the amount of operation of the brake pedal; a master cylinder (30) having a cylinder portion (31) forming a reservoir chamber (311) for storing brake fluid and a piston rod (32) connected to a brake pedal and configured to push out the brake fluid stored in the reservoir chamber and discharge it to the outside of the cylinder portion by moving a distance corresponding to the amount of operation of the brake pedal; a brake fluid flow path (40) that guides the brake fluid discharged from the reservoir chamber by being pushed out by the piston rod to the tank portion; a reaction force generating section (80) connected to the brake pedal and having an elastic member (82) that generates a reaction force on the brake pedal by elastically deforming in accordance with the amount of operation of the brake pedal; Wheel cylinders (2, 3, 4, 5) that are actuated by hydraulic pressure of brake fluid to apply braking force to the wheels of the vehicle; When the brake device is not malfunctioning, the brake fluid flowing through the brake fluid passage is guided to the wheel cylinder via the tank portion and the actuator, and a flow path switching unit (61, 62, 91) that guides the brake fluid flowing through the brake fluid flow path to the wheel cylinder without passing through the tank unit and the actuator when the brake device is out of order; Equipped with. The invention described in claim 3 is as follows: A braking device for braking a wheel of a vehicle, A brake pedal (10), a pedal operation detection unit (20) that detects an operation amount of a brake pedal; a tank portion (50) for storing brake fluid; an actuator (51) for pressurizing the brake fluid stored in the tank to a brake fluid pressure corresponding to the amount of operation of the brake pedal; a master cylinder (30) having a cylinder portion (31) forming a reservoir chamber (311) for storing brake fluid and a piston rod (32) connected to a brake pedal and configured to push out the brake fluid stored in the reservoir chamber and discharge it to the outside of the cylinder portion by moving a distance corresponding to the amount of operation of the brake pedal; a brake fluid flow path (40) that guides the brake fluid discharged from the reservoir chamber by being pushed out by the piston rod to the tank portion; a reaction force generating section (80) connected to the brake pedal and having an elastic member (82) that generates a reaction force on the brake pedal by elastically deforming in accordance with the amount of operation of the brake pedal; The brake pedal, master cylinder, and reaction force generating unit are provided inside the vehicle.

[0007] In this way, the reaction force generating unit generates a reaction force on the brake pedal by elastically deforming the elastic member in accordance with the amount of brake pedal operation, without using the hydraulic pressure of the brake fluid discharged from the master cylinder. This eliminates the need for brake fluid between the brake pedal and the reaction force generating unit. This allows the reaction force to be transmitted directly to the brake pedal, improving the feel of brake pedal operation.

[0008] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a brake device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view of the periphery of the reaction force generating portion according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described with reference to Figures 1 and 2. As shown in Figure 1, a brake device 1 of this embodiment is used to brake the wheels of a vehicle, which are a front left wheel FL, a front right wheel FR, a rear left wheel RL, and a rear right wheel RR.

[0011] As shown in Fig. 1, the brake device 1 includes a left front wheel cylinder 2, a right front wheel cylinder 3, a left rear wheel cylinder 4, and a right rear wheel cylinder 5. These wheel cylinders 2, 3, 4, and 5 are actuated by the hydraulic pressure of brake fluid to apply braking force to the left front wheel FL, right front wheel FR, left rear wheel RL, and right rear wheel RR, respectively. For convenience, the wheel cylinders will be referred to as W / C below.

[0012] The brake device 1 also includes a brake pedal 10, a stroke sensor 20, a master cylinder 30, a brake fluid flow path 40, a tank unit 50, a first actuator 51, a master bypass valve 61, a cut valve 62, a second actuator 70, and a reaction force generating unit 80. The brake device 1 also includes a power source 90, a first ECU 91, and a second ECU 92. ECU stands for Electronic Control Unit.

[0013] The left front wheel W / C2 is disposed corresponding to the left front wheel FL. The right front wheel W / C3 is disposed corresponding to the right front wheel FR. The left rear wheel W / C4 is disposed corresponding to the left rear wheel RL. The right rear wheel W / C5 is disposed corresponding to the right rear wheel RR. The left front wheel W / C2, right front wheel W / C3, left rear wheel W / C4, and right rear wheel W / C5 are each connected to a brake pad (not shown) of the vehicle.

[0014] The brake pedal 10 is an operating member that is operated by being stepped on by the vehicle driver and is provided inside the vehicle cabin. The brake pedal 10 has a pedal portion 11, a lever portion 12, and a rotating shaft 13. The pedal portion 11 is the portion that is stepped on by the vehicle driver. The lever portion 12 is a rod-shaped member, one end of which is connected to the pedal portion 11 and the other end of which is connected to the rotating shaft 13. The lever portion 12 is configured to be rotatable about the rotating shaft 13 when the pedal portion 11 is stepped on by the vehicle driver. In addition, a stroke sensor 20 is provided on the rotating shaft 13.

[0015] The stroke sensor 20 is a sensor that detects pedal operation information related to the amount of operation of the brake pedal 10 when the brake pedal 10 is operated by the driver. Specifically, the stroke sensor 20 is a rotation angle sensor that detects the rotation angle of the lever portion 12 that rotates when the driver depresses the pedal portion 11. The stroke sensor 20 outputs a detection signal corresponding to the rotation angle of the lever portion 12 about the rotation shaft 13 to a first ECU 91, which will be described later.

[0016] The stroke sensor 20 may output a detection signal corresponding to the stroke amount of the brake pedal 10, which changes depending on the depression of the pedal section 11 by the driver, to the first ECU 91. In this embodiment, the stroke sensor 20 functions as a pedal operation detection section.

[0017] The master cylinder 30 has a cylinder portion 31, a piston rod 32, and a master reservoir 33. The master cylinder 30 is provided inside the vehicle compartment, and is housed, for example, inside a dashboard (not shown) provided inside the vehicle compartment.

[0018] The cylinder portion 31 has a cylindrical shape with a bottom, and stores brake fluid, which is a working fluid, in a storage chamber 311 formed inside. A piston rod 32 is inserted into the cylinder portion 31 from the open side. A spring 312 is housed in the storage chamber 311 of the cylinder portion 31. The storage chamber 311 is connected to the master reservoir 33 and the brake fluid flow path 40.

[0019] The piston rod 32 closes the open side of the cylinder portion 31 and pushes out the brake fluid stored in the storage chamber 311 of the cylinder portion 31. The piston rod 32 is connected to the lever portion 12 of the brake pedal 10. When the driver depresses the pedal portion 11 and the lever portion 12 rotates about the rotation axis 13, the piston rod 32 moves in the axial direction of the cylinder portion 31 by a distance corresponding to the amount of operation of the brake pedal 10 and is pushed into the cylinder portion 31. By being pushed into the cylinder portion 31, the piston rod 32 pushes out the brake fluid stored in the storage chamber 311 to the outside of the cylinder portion 31.

[0020] The brake fluid pushed out from the cylinder portion 31 is discharged into the brake fluid flow path 40 and flows into the tank portion 50. When the driver stops depressing the pedal portion 11, the piston rod 32 moves to its original position by the biasing force of the spring 312 housed in the reservoir chamber 311.

[0021] As shown in Fig. 2, the cylinder portion 31 and the piston rod 32 are housed in a reaction force generating portion 80, which will be described later. Note that the master reservoir 33 is omitted from Fig. 2.

[0022] As described above, in the master cylinder 30 of this embodiment, the piston rod 32 is mechanically connected directly to the brake pedal 10, and when the driver depresses the brake pedal 10, the depression force generated in the pedal portion 11 is transmitted directly to the master cylinder 30. The master cylinder 30 is configured so that brake fluid does not flow between the brake pedal 10 and the piston rod 32.

[0023] The master reservoir 33 is a tank that stores brake fluid. The master reservoir 33 is configured to supply the stored brake fluid when the brake fluid in the cylinder portion 31 is insufficient, and to store brake fluid supplied from the cylinder portion 31 when the brake fluid in the cylinder portion 31 is in excess.

[0024] The brake fluid flow path 40 is a flow path that guides the brake fluid discharged from the cylinder portion 31 to the left front wheel W / C2, the right front wheel W / C3, the left rear wheel W / C4, and the right rear wheel W / C5 via the second actuator 70. One side of the brake fluid flow path 40 is connected to the cylinder portion 31. The other side of the brake fluid flow path 40 branches midway, and one of the branched flow paths is connected to the second actuator 70 via the tank portion 50 and the first actuator 51. The other branched flow path is connected to the second actuator 70 without passing through the tank portion 50 and the first actuator 51.

[0025] Hereinafter, one of the branched flow paths will be referred to as the first flow path 41, and the other flow path will be referred to as the second flow path 42. The first flow path 41 is a flow path that guides the brake fluid discharged from the cylinder portion 31 to each of the W / Cs 2, 3, 4, and 5 via the tank portion 50, the first actuator 51, and the second actuator 70. The second flow path 42 is a flow path that guides the brake fluid discharged from the cylinder portion 31 to each of the W / Cs 2, 3, 4, and 5 via the second actuator 70, without passing through the tank portion 50 and the first actuator 51.

[0026] The first flow path 41 is provided with a master bypass valve 61 that opens and closes the first flow path 41. The second flow path 42 is provided with a cut valve 62 that opens and closes the second flow path 42. In this embodiment, the master bypass valve 61 functions as a first control valve, and the cut valve 62 functions as a second control valve.

[0027] Although not shown, the brake device 1 of this embodiment has two piping systems that guide the brake fluid discharged from the cylinder portion 31 to the second actuator 70. That is, the brake device 1 has another piping system (not shown) that has the brake fluid flow path 40, the master bypass valve 61, and the cut valve 62. Also, although not shown, the master cylinder 30 of this embodiment has the reservoir chamber 311 divided into two spaces, and each of the two spaces functions as a reservoir that stores brake fluid. Then, each of the two reservoirs is independently connected to a flow path that guides the brake fluid discharged from the cylinder portion 31 to the second actuator 70.

[0028] Furthermore, the flow path connected to one of the two storage parts is connected to the left front wheel W / C2 and the right front wheel W / C3 via the second actuator 70. Furthermore, the flow path connected to the other of the two storage parts is connected to the left rear wheel W / C4 and the right rear wheel W / C5 via the second actuator 70. With this configuration, even if brake fluid cannot be flowed through one of the flow paths, the brake device 1 is configured to be able to brake the vehicle by flowing brake fluid through the other flow path.

[0029] The master bypass valve 61 is a normally closed two-position solenoid valve that can be controlled between a connected state and a cut-off state. Specifically, when the solenoid coil is de-energized, the master bypass valve 61 is in a cut-off state, thereby closing the first flow path 41 and preventing the brake fluid discharged from the cylinder portion 31 from flowing to the tank portion 50. When the solenoid coil is in a conductive state, the master bypass valve 61 is in an open state, thereby opening the first flow path 41 and allowing the brake fluid discharged from the cylinder portion 31 to flow to the tank portion 50.

[0030] The cut valve 62 is a normally open two-position solenoid valve that can be controlled between a connected state and a cut-off state. Specifically, when the solenoid coil is de-energized, the cut valve 62 is in a connected state, thereby opening the second flow path 42 and allowing the brake fluid discharged from the cylinder portion 31 to flow to the second actuator 70. When the solenoid coil is in a conductive state, the cut valve 62 is in a cut-off state, thereby closing the second flow path 42 and prohibiting the brake fluid discharged from the cylinder portion 31 from flowing to the second actuator 70 via the second flow path 42.

[0031] The master bypass valve 61 and the cut valve 62 are configured to be controllable by control signals transmitted from the first ECU 91, and receive power for driving them from a power source 90.

[0032] The tank unit 50 is a tank that stores brake fluid. The tank unit 50 is provided in the first flow path 41, and stores the brake fluid that flows in from the first flow path 41 when the brake fluid is discharged from the cylinder unit 31 while the master bypass valve 61 is in a communicating state. Here, the tank unit 50 has a space inside that can store a sufficient amount of brake fluid, and the air pressure in this internal space is approximately the same as atmospheric pressure.

[0033] Therefore, the brake fluid stored in the tank portion 50 due to the brake fluid flowing into the tank portion 50 from the first flow path 41 generates almost no reaction force on the piston rod 32. In other words, when the brake pedal 10 is operated by the driver, the master cylinder 30 does not generate a reaction force on the lever portion 12 corresponding to the depression force on the brake pedal 10. The tank portion 50 is connected to the first actuator 51 and is configured to be able to discharge the stored brake fluid to the first actuator 51.

[0034] The first actuator 51 is a pressurizing unit that pressurizes the brake fluid supplied from the tank unit 50 based on a control signal transmitted from the first ECU 91. In other words, the first actuator 51 is a pressurizing unit that pressurizes the brake fluid stored in the tank unit 50 to a brake fluid pressure that corresponds to the amount of operation of the brake pedal 10.

[0035] The first actuator 51 adjusts the brake fluid pressure of each of the left front wheel W / C2, the right front wheel W / C3, the left rear wheel W / C4, and the right rear wheel W / C5 by increasing the brake fluid pressure based on a control signal sent from the first ECU 91. In a brake device 1 equipped with such a first actuator 51, the force applied by the driver to the brake pedal 10 is not basically transmitted directly to each of the left front wheel W / C2, the right front wheel W / C3, the left rear wheel W / C4, and the right rear wheel W / C5. In other words, the brake device 1 of this embodiment is a so-called brake-by-wire type brake.

[0036] The first actuator 51 has a first pump 511 and a first pressure sensor 512. The first pump 511 is a pressurizing pump that increases the hydraulic pressure of the brake fluid by being driven by a motor (not shown). The motor is driven by power supplied from a power source 90, and the rotation speed of the motor is controlled based on a control signal from a first ECU 91. The first pump 511 increases the hydraulic pressure of the brake fluid supplied from the tank unit 50 by the driving force supplied from the motor. The first pump 511 is connected to the second actuator 70, and supplies pressurized brake fluid to the second actuator 70.

[0037] The first pressure sensor 512 is a pressure detection sensor that detects the hydraulic pressure of the brake fluid pressurized by the first pump 511. The first pressure sensor 512 is connected to the first ECU 91, and outputs a detection signal to the first ECU 91 in accordance with the detected hydraulic pressure.

[0038] The second actuator 70 has internal flow paths that communicate with the left front wheel W / C 2, the right front wheel W / C 3, the left rear wheel W / C 4, and the right rear wheel W / C 5, and guides the brake fluid that has flowed into the second actuator 70 from the first flow path 41 and the second flow path 42 to each of the W / Cs 2, 3, 4, and 5. The second actuator 70 has a control valve group 71, a second pump 72, and a second pressure sensor 73.

[0039] The control valve group 71 is a plurality of control valves that switch the flow paths inside the second actuator 70 based on control signals from the second ECU 92 and adjust the hydraulic pressure of the brake fluid flowing through those flow paths. Each control valve included in the control valve group 71 is provided in a flow path inside the second actuator 70 that guides the brake fluid flowing in from the first actuator 51 to a W / C2 for the left front wheel, a W / C3 for the right front wheel, a W / C4 for the left rear wheel, and a W / C5 for the right rear wheel. Each control valve included in the control valve group 71 is configured to be controllable by a control signal output from the second ECU 92.

[0040] The second pump 72 is a hydraulic pressure adjustment pump that is driven by a motor (not shown) to adjust the hydraulic pressure of the brake fluid supplied to each of the W / Cs 2, 3, 4, and 5. The motor is driven by power supplied from a power source 90, and the rotation speed of the motor is controlled based on a control signal from a second ECU 92. The second pump 72 adjusts the hydraulic pressure of the brake fluid flowing out of the first actuator 51 by the driving force supplied from the motor.

[0041] The second pump 72 is connected to each of the W / Cs 2, 3, 4, and 5 via respective flow paths leading to the W / Cs 2, 3, 4, and 5, and supplies brake fluid with adjusted hydraulic pressure to each of the W / Cs 2, 3, 4, and 5.

[0042] The second pressure sensor 73 is a pressure detection sensor that detects the hydraulic pressure of the brake fluid flowing through the flow path inside the second actuator 70. The second pressure sensor 73 is connected to the second ECU 92, and outputs a detection signal to the second ECU 92 according to the detected hydraulic pressure.

[0043] When the motors that drive the control valves in the control valve group 71 and the second pump 72 are not driven, the second actuator 70 discharges the brake fluid flowing in from the first actuator 51 to each of the W / Cs 2, 3, 4, and 5 without adjusting the fluid pressure.

[0044] The power supply 90 is a power supply unit that supplies power to various components of the brake device 1, such as the first ECU 91, the second ECU 92, the master bypass valve 61, and the cut valve 62. The power supply 90 is connected to these various components.

[0045] The first ECU 91 is composed of a microcomputer including a CPU, a storage unit such as a ROM and a RAM, and its peripheral circuits. The stroke sensor 20 and the first pressure sensor 512 are connected to the input side of the first ECU 91, and the master bypass valve 61, the cut valve 62, and a motor that drives the first pump 511 are connected to the output side. The first ECU 91 controls the rotation speed of the motor that drives the first pump 511 based on detection signals transmitted from the stroke sensor 20 and the first pressure sensor 512. The first ECU 91 also controls the operation of the master bypass valve 61 and the cut valve 62 based on detection signals transmitted from the stroke sensor 20. The storage units such as the ROM and RAM of the first ECU 91 are composed of non-transient tangible storage media.

[0046] Specifically, when the first ECU 91 detects via the stroke sensor 20 that the driver is depressing the pedal unit 11, it supplies power to the solenoid coil of the master bypass valve 61 to open the master bypass valve 61. In addition, when the first ECU 91 detects via the stroke sensor 20 that the driver is depressing the pedal unit 11, it supplies power to the solenoid coil of the cut valve 62 to close the cut valve 62.

[0047] In other words, when the driver depresses the pedal section 11, the first ECU 91 prohibits the brake fluid discharged from the cylinder section 31 from flowing into the second flow path 42, and allows the brake fluid discharged from the cylinder section 31 to flow into the first flow path 41.

[0048] On the other hand, if the brake device 1 fails, the flow path through which the brake fluid discharged from the cylinder portion 31 flows is switched from the first flow path 41 to the second flow path 42. Specifically, if the master bypass valve 61 and the cut valve 62 are not driven due to a failure of the first ECU 91, the power source 90, or the like, the flow paths from the cylinder portion 31 to each of the W / Cs 2, 3, 4, and 5 are switched.

[0049] The reason for this switching of the flow path will be explained below. If a failure in the power supply 90 prevents power from being supplied to the master bypass valve 61, the supply of power to the solenoid coil of the master bypass valve 61 is stopped, and the master bypass valve 61 enters a shut-off state. Also, if a failure in the power supply 90 prevents power from being supplied to the cut valve 62, the supply of power to the solenoid coil of the cut valve 62 is stopped, and the cut valve 62 enters an open state.

[0050] Furthermore, if a control signal cannot be sent from the first ECU 91 to the master bypass valve 61 due to a failure of the first ECU 91, the master bypass valve 61 will be shut off, similar to a failure of the power supply 90. If a control signal cannot be sent from the first ECU 91 to the cut valve 62 due to a failure of the first ECU 91, the cut valve 62 will be open, similar to a failure of the power supply 90.

[0051] That is, when the brake device 1 fails and the operation of the master bypass valve 61 and the cut valve 62 cannot be controlled, the brake fluid discharged from the cylinder portion 31 is prohibited from flowing to the first flow path 41 and flows to the second actuator 70 via the second flow path 42. In this manner, depending on whether the brake device 1 is in a normal state or in a failed state, the flow path through which the brake fluid discharged from the cylinder portion 31 flows is switched by the master bypass valve 61, the cut valve 62, and the first ECU 91. In this embodiment, the master bypass valve 61, the cut valve 62, and the first ECU 91 function as a flow path switching unit.

[0052] The first ECU 91 may be configured to be able to detect a failure of the first actuator 51. The failure of the first actuator 51 detected by the first ECU 91 may be, for example, a failure of the first pump 511, the first pressure sensor 512, the motor that drives the first pump 511, or the like.

[0053] The first ECU 91 may be configured to place the master bypass valve 61 in a closed state and the cut valve 62 in a communicating state when a failure of the first actuator 51 is detected. In this case, the first ECU 91 may be configured to place the master bypass valve 61 in a communicating state and the cut valve 62 in a closed state when a failure of the first actuator 51 is not detected.

[0054] The second ECU 92 is composed of a microcomputer including a CPU and storage units such as a ROM and a RAM, and its peripheral circuits. The second ECU 92 has an input side connected to the second pressure sensor 73, and an output side connected to each control valve provided in the control valve group 71 of the second actuator 70 and a motor that drives the second pump 72. The second ECU 92 controls the operation of each control valve provided in the control valve group 71 and the rotation speed of the motor that drives the second pump 72 based on the detection signal transmitted from the second pressure sensor 73. The storage units such as the ROM and RAM of the second ECU 92 are composed of non-transient tangible storage media.

[0055] Next, the reaction force generating unit 80 will be described with reference to Fig. 2. The reaction force generating unit 80 is a device that generates a reaction force in the brake pedal 10 corresponding to the force applied by the driver to the brake pedal 10, thereby providing the driver with a sense of operation of the brake pedal 10. The reaction force generating unit 80 has a housing 81 and an elastic member 82.

[0056] The housing 81 is a housing that houses the elastic member 82, the cylinder portion 31, and the piston rod 32. The housing 81 is provided inside the vehicle cabin. Specifically, the housing 81 is attached to a dash panel D, which is a partition that separates the interior of the vehicle from the outside of the vehicle, such as the engine compartment, inside a dashboard (not shown) provided inside the vehicle cabin. The dash panel D is also sometimes referred to as a bulkhead. Hereinafter, for convenience of explanation, the direction above the front of the vehicle will be simply referred to as "upper," and the direction below the front of the vehicle will be simply referred to as "lower."

[0057] Housing 81 is a hollow, bottomed rectangular cylinder, and the outer wall portion surrounding the hollow portion has an outer wall portion that is attached to dash panel D that protrudes upward and downward. Housing 81 is attached to dash panel D at the protruding portion so that the upper side of housing 81 is the bottom side and the lower side is the opening side. Housing 81 has a first attachment portion 811, a second attachment portion 812, a housing bottom portion 813, and a housing tubular portion 814.

[0058] 2, the master reservoir 33 may be attached to the outer periphery of the housing 81. The master reservoir 33 may also be housed within the housing 81.

[0059] First mounting portion 811 and second mounting portion 812 are members for mounting housing 81 to dash panel D, and are portions that protrude upward and downward from the outer wall portion. First mounting portion 811 is connected to housing bottom portion 813, which will be described later, and extends upward from housing bottom portion 813. First mounting portion 811 is also formed with first mounting hole 815. First mounting portion 811 is mounted to dash panel D by inserting bolt B into first mounting hole 815 and first hole D1 in dash panel D. Note that here, bolt B is inserted so as not to penetrate dash panel D.

[0060] Second mounting portion 812 is connected to housing tubular portion 814, which will be described later, and extends downward from housing tubular portion 814. Second mounting portion 812 is also formed with second mounting hole 816. Second mounting portion 812 is attached to dash panel D by inserting bolt B into second mounting hole 816 and second hole D2 in dash panel D.

[0061] The housing bottom 813 is a bottom portion of the bottomed cylindrical housing 81. The housing bottom 813 supports a part of the lever portion 12 so that the lever portion 12 can rotate around the rotation shaft 13, and also supports the stroke sensor 20.

[0062] The housing tubular portion 814 is a portion that forms a reaction force accommodating portion 817 that accommodates the elastic member 82. The housing tubular portion 814 is a square tube, is connected to the housing bottom portion 813, and extends downward from the housing bottom portion 813. The housing tubular portion 814 accommodates the elastic member 82, and the portion of the lever portion 12 that is connected to the elastic member 82 is accommodated in the reaction force accommodating portion 817.

[0063] The housing cylindrical portion 814 is formed with a flow path hole 818 for guiding the brake fluid flow path 40 to the reaction force accommodating portion 817. The brake fluid flow path 40 is inserted through a through hole D3 and the flow path hole 818 formed in the dash panel D, and is connected to the cylinder portion 31 of the master cylinder 30.

[0064] The bottom portion of the cylinder portion 31 is attached to the inner wall surface of the housing tubular portion 814. The piston rod 32 inserted into the opening side of the cylinder portion 31 is connected to the front surface 12a of the lever portion 12.

[0065] The elastic member 82 is a member that generates a reaction force in the lever portion 12 according to the force applied by the driver to the brake pedal 10. Specifically, the elastic member 82 is connected to the inner wall surface of the housing tubular portion 814 and the lever portion 12, and generates a reaction force in the lever portion 12 according to the rotation angle of the lever portion 12 that rotates when the driver depresses the pedal portion 11. The elastic member 82 in this embodiment is made of a member having a predetermined elastic coefficient.

[0066] The elastic member 82 is, for example, an equally spaced spring, and is arranged so as to be elastically deformable along the longitudinal direction of the vehicle. The front side of the elastic member 82 is connected to the front surface of the inner wall surface of the housing tubular portion 814, and the rear side is connected to the front surface 12a of the lever portion 12. When the driver is not depressing the pedal portion 11, the elastic member 82 is arranged so that it is not stretched or contracted, i.e., does not generate elastic force. In other words, the elastic member 82 is arranged so that its length is at its natural length when the driver is not depressing the pedal portion 11.

[0067] In this way, the elastic member 82 of this embodiment is mechanically connected directly to the brake pedal 10 without going through the master cylinder 30. In addition, the elastic member 82 is connected directly to the brake pedal 10 without going through the brake fluid flow path 40 through which the brake fluid flows, and the brake fluid does not flow between the brake pedal 10 and the elastic member 82.

[0068] When the pedal unit 11 is depressed by the pedal force of the driver, a force corresponding to this depression force is transmitted from the lever unit 12 to the elastic member 82. This causes the elastic member 82 to elastically deform, and a restoring force is generated in the elastic member 82. Specifically, the elastic member 82, which is made up of a spring with equal intervals of pitch, contracts when the pedal unit 11 is depressed by the pedal force of the driver, and generates a restoring force to return from the contracted state to the state before contraction. This restoring force generates a reaction force against the lever unit 12.

[0069] The restoring force of the elastic member 82 is proportional to the amount of deformation of the elastic member 82. Furthermore, the amount of deformation of the elastic member 82 increases as the rotation angle of the lever portion 12 increases. Therefore, the restoring force of the elastic member 82 increases as the rotation angle of the lever portion 12 increases. In this embodiment, the elastic member 82 is set so that the rotation angle of the lever portion 12 and the reaction force have a linear relationship.

[0070] Next, a description will be given of the operation of the brake device 1. First, a description will be given of the operation when the brake device 1 is in a normal state without any failure and in a state in which power can be supplied from the power source 90 to the master bypass valve 61 and the cut valve 62.

[0071] When the brake device 1 is not malfunctioning, in an initial state where the driver is not depressing the brake pedal 10, the first ECU 91 does not send control signals to the master bypass valve 61 and the cut valve 62. That is, the first ECU 91 puts the master bypass valve 61 in a closed state and the cut valve 62 in a connected state. This puts the reservoir chamber 311 of the cylinder portion 31 in communication with the second actuator 70 via the second flow path 42.

[0072] In the initial state where the driver is not depressing the brake pedal 10, the lever portion 12 is not rotating. When the driver depresses the brake pedal 10, the lever portion 12 rotates around the rotation shaft 13. This changes the rotation angle of the lever portion 12.

[0073] When the lever portion 12 rotates around the rotary shaft 13, the stroke sensor 20 detects the rotation angle of the lever portion 12 and outputs a detection signal corresponding to the rotation angle to the first ECU 91. Then, when the first ECU 91 detects that the lever portion 12 has rotated, it sends control signals to the master bypass valve 61 and the cut valve 62, thereby bringing the master bypass valve 61 into a communicating state and bringing the cut valve 62 into a blocking state. As a result, the storage chamber 311 of the cylinder portion 31 is connected to the first actuator 51 via the first flow path 41, and the storage chamber 311 of the cylinder portion 31 is disconnected from the second actuator 70.

[0074] Furthermore, when the lever portion 12 rotates around the rotation axis 13, the piston rod 32 connected to the lever portion 12 is pushed into the cylinder portion 31. As a result, the brake fluid stored in the cylinder portion 31 is discharged into the brake fluid flow path 40. When the brake fluid is discharged from the cylinder portion 31 into the brake fluid flow path 40, the tank portion 50 stores the brake fluid flowing in from the first flow path 41. At this time, the brake fluid in the tank portion 50 is hardly pressurized. Furthermore, no brake fluid pressure is generated in the brake fluid in the brake fluid flow path 40.

[0075] Furthermore, the first ECU 91 calculates a target brake fluid pressure based on the detection signal of the stroke sensor 20. Then, the first ECU 91 controls the rotation speed of the motor that drives the first pump 511 so that the hydraulic pressure of the brake fluid flowing from the tank unit 50 to the first actuator 51 approaches the target brake fluid pressure. The first pressure sensor 512 detects the hydraulic pressure of the brake fluid pressurized by the first pump 511 and outputs a detection signal corresponding to the detected hydraulic pressure to the first ECU 91. The first ECU 91 adjusts the brake fluid pressure so that it approaches the target brake fluid pressure by performing feedback control. Then, the first actuator 51 causes the brake fluid with the adjusted hydraulic pressure to flow into the second actuator 70.

[0076] Furthermore, when the driver depresses the brake pedal 10, the second ECU 92 determines whether or not the conditions for executing the ABS control and the ESC control are met.

[0077] When the conditions for executing ABS control and the conditions for executing ESC control are not satisfied, the second ECU 92 causes the brake fluid pressurized by the first actuator 51 to approach the target brake fluid pressure to flow into each of the W / Cs 2, 3, 4, and 5 without adjusting the fluid pressure. As a result, the brake fluid that has flowed from the first actuator 51 to the second actuator 70 flows into each of the W / Cs 2, 3, 4, and 5. Therefore, each brake pad (not shown) provided on each of the wheels FL, FR, RL, and RR comes into frictional contact with the corresponding brake disc, decelerating the vehicle.

[0078] The determination of whether or not to execute ABS control is made by calculating the slip ratios of the left front wheel FL, right front wheel FR, left rear wheel RL, and right rear wheel RR based on the vehicle wheel speed and vehicle speed. When the conditions for executing ABS control are met, the second ECU 92 controls the control valves provided in the control valve group 71 of the second actuator 70 based on the slip ratios to adjust the hydraulic pressure of the brake fluid flowing to each of the W / Cs 2, 3, 4, and 5. In this way, the slip ratios of the vehicle's wheels are controlled, thereby preventing the left front wheel FL, right front wheel FR, left rear wheel RL, and right rear wheel RR from locking.

[0079] The determination of whether to execute ESC control is made by calculating the vehicle's skid state based on, for example, the yaw rate, steering angle, acceleration, wheel speed, vehicle speed, etc. When the conditions for executing ESC control are met, the second ECU 92 selects wheels to be controlled to stabilize the turning of the vehicle based on the vehicle's skid state.

[0080] Furthermore, the second ECU 92 drives the motor that drives the second pump 72 to pressurize the W / C corresponding to the selected wheel to be controlled, in addition to controlling each control valve provided in the control valve group 71. The brake fluid pressurized by the second pump 72 flows to the W / C corresponding to the wheel to be controlled. This pressurizes the W / C corresponding to the wheel to be controlled, suppressing skidding of the vehicle. This stabilizes the vehicle's running.

[0081] In this way, the second ECU 92 performs ABS control, ESC control, etc. At this time, in addition to the ABS control and ESC control described above, the second ECU 92 may also perform collision avoidance control, regenerative cooperative control, etc. based on control signals from another ECU (not shown).

[0082] Furthermore, when the lever portion 12 rotates around the rotation shaft 13, the elastic member 82 is pressed by the lever portion 12 and contracts. As a result, the elastic member 82 generates a reaction force in the lever portion 12 due to the restoring force. That is, the elastic member 82 generates a reaction force in the brake pedal 10 that corresponds to the force applied by the driver to the pedal portion 11. The greater the deformation amount of the elastic member 82, the greater the reaction force that the elastic member 82 generates in the brake pedal 10.

[0083] As described above, the brake fluid discharged from the cylinder portion 31 when the driver depresses the brake pedal 10 simply moves into the tank portion 50 without generating brake fluid pressure. Therefore, almost no reaction force based on the brake fluid pressure is generated against the brake pedal 10.

[0084] When the driver's foot is released from the pedal portion 11, the reaction force generating portion 80 returns the brake pedal 10 to its initial state by the restoring force of the elastic member 82.

[0085] In this way, when the brake device 1 is not malfunctioning, when the driver depresses the brake pedal 10, the brake fluid stored in the reservoir chamber 311 is discharged into the brake fluid flow path 40 by the piston rod 32 being pushed into the cylinder portion 31. In addition, the master bypass valve 61 is brought into a communicating state and the cut valve 62 is brought into a blocking state, so that the brake fluid discharged into the brake fluid flow path 40 is led to the tank portion 50.

[0086] Next, a description will be given of a case where the brake device 1 is in a faulty state. Here, the case where the brake device 1 is in a faulty state will be described by taking as an example a case where the power supply 90 has failed and is unable to supply power to the master bypass valve 61 and the cut valve 62.

[0087] If the brake device 1 is in a malfunction state, such as if the power supply 90 fails, the master bypass valve 61 and the cut valve 62 cannot receive power from the power supply 90. In this case, in the initial state where the driver is not depressing the brake pedal 10, the reservoir chamber 311 of the cylinder portion 31 is in communication with the second actuator 70 via the second flow path 42, just as when the brake device 1 is not malfunctioning.

[0088] When the driver depresses the brake pedal 10, the piston rod 32 connected to the lever portion 12 is pushed into the cylinder portion 31. As a result, the brake fluid stored in the cylinder portion 31 is discharged into the brake fluid flow path 40.

[0089] However, because power cannot be supplied from the power supply 90, the master bypass valve 61 and the cut valve 62 cannot be driven even if they receive a control signal from the first ECU 91. Therefore, the reservoir chamber 311 of the cylinder portion 31 remains in communication with the second actuator 70 via the second flow path 42. When brake fluid is discharged from the cylinder portion 31 to the brake fluid flow path 40, the brake fluid flows from the second flow path 42 into the second actuator 70 and further into each of the W / Cs 2, 3, 4, and 5.

[0090] Furthermore, when the brake fluid flows into each of the W / Cs 2, 3, 4, and 5, it is pressurized by the force applied by the driver to the pedal unit 11. Therefore, each brake pad (not shown) provided on each of the wheels FL, FR, RL, and RR comes into frictional contact with the corresponding brake disc, decelerating the vehicle. In this way, even in a fault state where the power supply 90 of the brake device 1 has failed, the brake device 1 can brake the vehicle in the same way as in a normal state.

[0091] Furthermore, when the lever portion 12 rotates around the rotation shaft 13, the elastic member 82 is pressed by the lever portion 12 and contracts, just as when the brake device 1 is not malfunctioning. As a result, the elastic member 82 generates a reaction force associated with the restoring force in the lever portion 12. That is, the elastic member 82 generates a reaction force in the brake pedal 10 that corresponds to the force applied to the pedal portion 11 by the driver.

[0092] When the brake device 1 is in a malfunction state, the reservoir chamber 311 communicates with each of the W / Cs 2, 3, 4, and 5 via the second flow path 42 and the second actuator 70. The brake fluid present in the reservoir chamber 311, the second flow path 42, the second actuator 70, and each of the W / Cs 2, 3, 4, and 5 is pressurized to brake fluid pressure by the driver's depression force on the pedal unit 11. As a result, the brake fluid generates a reaction force in the piston rod 32 that corresponds to the driver's depression force.

[0093] Therefore, when the brake device 1 is in a malfunctioning state, a reaction force is applied to the brake pedal 10 not only from the elastic member 82 but also from the brake fluid pressurized to the brake fluid pressure. In other words, when the brake device 1 is in a malfunctioning state, a larger reaction force is applied to the brake pedal 10 than when the brake device 1 is normal.

[0094] When the driver's foot is released from the pedal portion 11, the brake pedal 10 returns to its initial state due to the reaction force generated by the elastic member 82 and the reaction force generated by the brake fluid.

[0095] In this way, when the brake device 1 is malfunctioning, if the driver depresses the brake pedal 10, the brake fluid stored in the reservoir chamber 311 is discharged into the brake fluid flow path 40, just as when the brake device 1 is not malfunctioning. Also, by shutting off the master bypass valve 61 and opening the cut valve 62, the brake fluid discharged into the brake fluid flow path 40 is guided to each of the W / Cs 2, 3, 4, and 5 without passing through the tank unit 50 and the first actuator 51.

[0096] Although the case where the power supply 90 has failed has been described here as an example of a case where the brake device 1 is in a failure state, failures in other components other than the power supply 90 are also conceivable. For example, another example of a case where the brake device 1 is in a failure state is a case where the first ECU 91 has failed. In this case, even if the power supply 90 is not in failure, the first ECU 91 cannot send control signals to the master bypass valve 61 and the cut valve 62, and therefore the same operation as when the power supply 90 has failed is performed.

[0097] Another example of a case where the brake device 1 is in a failure state is a case where the first actuator 51 is broken. When the first ECU 91 detects a failure of the first actuator 51, the first ECU 91 may control the various components so that the devices operate in the same way as when the power supply 90 is broken.

[0098] Another example of a case where the brake device 1 is in a fault state is a case where the master bypass valve 61 and the cut valve 62 are faulty. When the first ECU 91 detects a fault in the master bypass valve 61 and the cut valve 62, the first ECU 91 may control the various components to operate in the same way as when the power supply 90 is faulty.

[0099] As described above, in the brake device 1 of this embodiment, the elastic member 82 is mechanically connected directly to the brake pedal 10 without passing through the master cylinder 30. When the driver depresses the pedal portion 11, brake fluid does not flow between the brake pedal 10 and the elastic member 82.

[0100] If the component that generates a reaction force to the brake pedal 10 is configured to have a flow path through which brake fluid flows, such as a stroke simulator, a seal member is provided at the location connecting the flow path to the stroke simulator. When pressurized brake fluid flows into the flow path when the driver depresses the pedal portion 11, the pressurized brake fluid may deform the seal member, which may result in air being mixed into the flow path.

[0101] The inclusion of air changes the reaction force generated by the stroke simulator, which can cause the driver to experience an inappropriate feeling when pressing the brake pedal 10. Furthermore, if air is included in the flow path, there is a risk that the reaction force will not be generated from the stroke simulator.

[0102] In contrast, in the brake device 1 of this embodiment, the elastic member 82 is mechanically connected directly to the brake pedal 10 without going through the master cylinder 30. Therefore, no brake fluid is interposed between the brake pedal 10 and the elastic member 82. Therefore, the reaction force generated by the elastic member 82 can be transmitted directly to the brake pedal 10, thereby improving the operating feel of the brake pedal 10.

[0103] In addition, the brake device 1 of this embodiment is a brake-by-wire type brake in which, when operating under normal conditions, the force applied by the driver to the brake pedal 10 is not directly transmitted to the W / C2 for the left front wheel, the W / C3 for the right front wheel, the W / C4 for the left rear wheel, and the W / C5 for the right rear wheel.

[0104] Therefore, when the brake device 1 is in a normal state, the brake fluid discharged from the master cylinder 30 moves into the tank portion 50 without being pressurized by the brake fluid pressure.

[0105] Therefore, compared to a configuration in which brake fluid pressurized to brake fluid pressure flows through the brake fluid flow path 40 regardless of whether the brake device 1 is in a normal state or an abnormal state, the load on the seal member provided in the brake fluid flow path 40 is reduced. Therefore, it is possible to suppress the occurrence of air being mixed into the brake fluid flow path 40 due to deformation of the seal member.

[0106] Furthermore, according to the above embodiment, the following effects can be obtained.

[0107] (1) In the above embodiment, the brake pedal 10, the reaction force generating unit 80, and the master cylinder 30 are provided inside the vehicle compartment.

[0108] If reaction force generating unit 80 and master cylinder 30 were to be provided outside the vehicle cabin, for example, in the engine compartment, reaction force generating unit 80 and master cylinder 30 would be connected to brake pedal 10 across dash panel D. In this case, when designing brake device 1, it is necessary to take into consideration both the installation space in the engine compartment outside the vehicle cabin and the installation space in the dash panel inside the vehicle cabin.

[0109] In contrast, in the brake device 1 of this embodiment, the brake pedal 10, the reaction force generating unit 80, and the master cylinder 30 are provided inside the vehicle compartment, without being separated by the dash panel D. Therefore, when designing the brake device 1, only the installation space inside the vehicle compartment needs to be considered, and the degree of freedom in the installation position of the brake device 1 can be improved.

[0110] (2) In the above embodiment, the brake device 1 includes the W / Cs 2, 3, 4, and 5 that are actuated by the hydraulic pressure of the brake fluid to apply braking force to the wheels of the vehicle, the master bypass valve 61 that functions as a flow path switching unit, the cut valve 62, and the first ECU 91. When the brake device 1 is not malfunctioning, the brake device 1 guides the brake fluid flowing through the brake fluid flow path 40 to the W / Cs 2, 3, 4, and 5 via the tank unit 50 and the first actuator 51. When the brake device 1 is malfunctioning, the brake device 1 guides the brake fluid flowing through the brake fluid flow path 40 to the W / Cs 2, 3, 4, and 5 without passing through the tank unit 50 and the first actuator 51.

[0111] According to this, when the brake device 1 is not malfunctioning, the brake device 1 causes pressurized brake fluid to flow from the first actuator 51 into each of the W / Cs 2, 3, 4, and 5 based on the rotation angle of the lever portion 12 detected by the stroke sensor 20. Therefore, when the brake device 1 is not malfunctioning, the hydraulic pressure of the brake fluid pressurized by the first actuator 51 activates each of the W / Cs 2, 3, 4, and 5 to apply braking force to the wheels.

[0112] Furthermore, if the brake device 1 fails, the brake device 1 can supply the brake fluid discharged from the master cylinder 30 to each of the W / Cs 2, 3, 4, and 5 without passing through the tank unit 50 and the first actuator 51. Therefore, even if the brake device 1 fails, each of the W / Cs 2, 3, 4, and 5 can be pressurized, and the vehicle can be braked.

[0113] (3) In the above embodiment, the brake fluid flow path 40 has a first flow path 41 and a second flow path 42. The first flow path 41 guides the brake fluid discharged from the cylinder portion 31 to each of the W / Cs 2, 3, 4, and 5 via the tank portion 50 and the first actuator 51. The second flow path 42 guides the brake fluid discharged from the cylinder portion 31 to each of the W / Cs 2, 3, 4, and 5 without passing through the tank portion 50 and the first actuator 51. The brake device 1 also has a normally closed master bypass valve 61 disposed in the first flow path 41 and a normally open cut valve 62 disposed in the second flow path 42.

[0114] When the brake device 1 is not malfunctioning, the brake device 1 places the master bypass valve 61 in a communicating state and the cut valve 62 in a shutoff state. The brake device 1 then guides the brake fluid discharged from the cylinder section 31 to each of the W / Cs 2, 3, 4, and 5 via the tank section 50 and the first actuator 51. When the brake device 1 is malfunctioning, the master bypass valve 61 is shut off. When the brake device 1 is malfunctioning, the cut valve 62 is connected. The brake device 1 then guides the brake fluid discharged from the cylinder section 31 to each of the W / Cs 2, 3, 4, and 5 without passing through the tank section 50 and the first actuator 51.

[0115] According to this, even if the brake device 1 fails, the brake fluid discharged from the master cylinder 30 can be supplied to each of the W / Cs 2, 3, 4, and 5 without performing any special control. Therefore, even if the brake device 1 fails, the vehicle can be braked reliably.

[0116] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0117] In the above-described embodiment, an example has been described in which the elastic member 82 is configured as an evenly spaced spring, but this is not limiting. For example, the elastic member 82 may be formed of a spring with a shape different from an evenly spaced spring, such as an unevenly spaced spring or a conical coil spring. Furthermore, the elastic member 82 may be formed of an elastic material other than a spring, such as a rubber material.

[0118] In the above embodiment, the reaction force generating unit 80 has been described as having one elastic member 82, but is not limited to this. For example, the reaction force generating unit 80 may have a plurality of elastic members 82, and the plurality of elastic members 82 may be connected in series or in parallel.

[0119] In the above embodiment, the brake pedal 10, the reaction force generating unit 80, and the master cylinder 30 are provided inside the vehicle cabin, but the present invention is not limited to this. For example, at least one of the reaction force generating unit 80 and the master reservoir 33 may be provided outside the vehicle cabin.

[0120] In the above embodiment, an example has been described in which the flow path through which the brake fluid flows is switched between the first flow path 41 and the second flow path 42 depending on whether the brake device 1 is malfunctioning or not, but this is not limiting. For example, the brake device 1 may be configured so that the flow path through which the brake fluid flows does not switch between the first flow path 41 and the second flow path 42. Specifically, the brake device 1 may be configured not to include the second flow path 42 through which the brake fluid flows when the brake device 1 is malfunctioning.

[0121] In the above embodiment, an example has been described in which the brake device 1 includes the first ECU 91 and the second ECU 92, and each ECU 91, 92 controls different devices. However, the present invention is not limited to this. For example, the brake device 1 may include a single ECU that controls various components of the brake device 1.

[0122] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0123] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0124] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are fundamentally limited to specific shapes, positional relationships, etc. [Explanation of symbols]

[0125] 10. Brake pedal 20 Pedal operation detector 30 Master cylinder 31 Cylinder section 32 Piston rod 40 Brake fluid flow path 50 Tank section 51 Actuator 80 Reaction force generating section 82 Elastic member

Claims

1. A braking device for braking a wheel of a vehicle, A brake pedal (10); a pedal operation detection unit (20) that detects the amount of operation of the brake pedal; a tank portion (50) for storing brake fluid; an actuator (51) that pressurizes the brake fluid stored in the tank portion to a brake fluid pressure corresponding to the operation amount of the brake pedal; a master cylinder (30) having a cylinder portion (31) forming a reservoir chamber (311) for storing the brake fluid, and a piston rod (32) connected to the brake pedal, which moves a distance corresponding to the amount of operation of the brake pedal to push out the brake fluid stored in the reservoir chamber and discharge it to the outside of the cylinder portion; a brake fluid flow path (40) that guides the brake fluid discharged from the storage chamber by being pushed out by the piston rod to the tank portion; a reaction force generating section (80) connected to the brake pedal and having an elastic member (82) that generates a reaction force on the brake pedal by elastically deforming in accordance with the amount of operation of the brake pedal; wheel cylinders (2, 3, 4, 5) that are actuated by the hydraulic pressure of the brake fluid to apply braking force to the wheels of the vehicle; When the brake device is not malfunctioning, the brake fluid flowing through the brake fluid passage is guided to the wheel cylinder via the tank portion and the actuator, and a flow path switching unit (61, 62, 91) that, when the brake device is malfunctioning, guides the brake fluid flowing through the brake fluid flow path to the wheel cylinder without passing through the tank unit and the actuator.

2. The brake fluid flow path includes a first flow path (41) that guides the brake fluid discharged from the cylinder portion to the wheel cylinder via the tank portion and the actuator, and a second flow path (42) that guides the brake fluid discharged from the cylinder portion to the wheel cylinder without passing through the tank portion and the actuator, The flow path switching unit has a first control valve (61) of a normally closed type that is disposed in the first flow path, and a second control valve (62) of a normally open type that is disposed in the second flow path, 2. The brake device according to claim 1, wherein, when the brake device is not malfunctioning, the first control valve is set to a communicating state and the second control valve is switched to a blocking state, thereby directing the brake fluid discharged from the cylinder portion to the wheel cylinder via the tank portion and the actuator, and when the brake device is malfunctioning, the first control valve is set to a blocking state and the second control valve is switched to a communicating state, thereby directing the brake fluid discharged from the cylinder portion to the wheel cylinder without passing through the tank portion and the actuator.

3. A braking device for braking a wheel of a vehicle, A brake pedal (10); a pedal operation detection unit (20) that detects the amount of operation of the brake pedal; a tank portion (50) for storing brake fluid; an actuator (51) that pressurizes the brake fluid stored in the tank portion to a brake fluid pressure corresponding to the operation amount of the brake pedal; a master cylinder (30) having a cylinder portion (31) forming a reservoir chamber (311) for storing the brake fluid, and a piston rod (32) connected to the brake pedal, which moves a distance corresponding to the amount of operation of the brake pedal to push out the brake fluid stored in the reservoir chamber and discharge it to the outside of the cylinder portion; a brake fluid flow path (40) that guides the brake fluid discharged from the storage chamber by being pushed out by the piston rod to the tank portion; a reaction force generating section (80) connected to the brake pedal and having an elastic member (82) that generates a reaction force on the brake pedal by elastically deforming in accordance with the amount of operation of the brake pedal, The brake pedal, the master cylinder, and the reaction force generating unit are provided inside a passenger compartment of the vehicle.

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