JP2008265515A - Brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize excellent brake operation feeling when changing a control mode. <P>SOLUTION: The brake control device 20 comprises a simulator cut valve 68 provided on the way of a flow path connecting a master cylinder 32 and a stroke simulator 69 to each other, and a brake ECU 70 for selecting one of a plurality of preset control modes and for controlling the simulator cut valve 68 based on the selected control mode. In the case of changing control mode during the operation of a brake pedal 24, if the control mode before changing control mode is the control mode for closing the simulator cut valve 68, the brake ECU 70 continuously closes the simulator cut valve 68 in the control mode after changing control mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brake control device that controls braking force applied to wheels provided in a vehicle.

Patent Document 1 describes a hydraulic brake device that includes a hydraulic booster, a master cylinder, a power hydraulic pressure source, and a plurality of brake cylinders. According to this hydraulic brake device, a plurality of brake cylinders, a hydraulic booster, a master cylinder, and a power hydraulic pressure source can be selectively communicated with each other with a simple circuit, and controllability can be improved. In this brake control device, regenerative cooperative control is performed in which a regenerative brake and a hydraulic brake are coordinated to generate a desired braking force. In this case, basically, hydraulic fluid is supplied from the power hydraulic pressure source to the brake cylinder. On the other hand, in this brake control device, it is also possible to generate a braking force by switching to another control mode depending on the situation. When the control mode is changed, the open / close states of a plurality of control valves in the brake device are changed.
JP 2006-123889 A

  By the way, the control mode may be changed during operation of the brake operation member. Changing the open / closed state of each control valve may affect the operational feeling of the brake operation member. For example, when the master cylinder and the stroke simulator are connected during the brake operation, the brake operation member may be displaced more than the driver expects as the hydraulic fluid starts to flow into the stroke simulator. It is desirable to provide a good feeling of brake operation regardless of the change of the control mode.

  Therefore, an object of the present invention is to provide a brake control technique capable of realizing a good brake operation feeling when the control mode is changed.

  A brake control device according to an aspect of the present invention includes a brake operation member that receives an operation input by a driver, a master cylinder that pressurizes the stored hydraulic fluid according to the operation input, and supply of the hydraulic fluid from the master cylinder. One is selected from a stroke simulator that generates a reaction force against the operation input, a simulator cut valve provided in the middle of the flow path connecting the master cylinder and the stroke simulator, and a plurality of preset control modes. A control unit that controls the simulator cut valve in accordance with the selected control mode, wherein the control unit changes the control mode while the brake operation member is being operated before the change. If the control mode is the control mode that closes the simulator cut valve Closes the simulator cut valve be continued in the control mode.

  According to this aspect, during the brake operation by the driver, the closed state of the simulator cut valve is maintained regardless of the change of the control mode. As a result, it is possible to prevent the hydraulic fluid from flowing from the master cylinder to the stroke simulator from being started during the brake operation. If the hydraulic fluid outflow to the stroke simulator is started during the brake operation triggered by the change of the control mode, the driver's feeling of operation of the brake operation member may change unintentionally. For example, when the brake operation member is a brake pedal, the pedal may enter. This is because the hydraulic fluid capacity of the stroke simulator is relatively large, and the displacement of the brake operation member increases as the hydraulic fluid in the master cylinder decreases. Therefore, by maintaining the closed state of the simulator cut valve regardless of the change of the control mode during the brake operation, it is possible to realize a good brake operation feeling such as preventing the pedal from entering, for example. Become.

  A plurality of wheel cylinders for applying a braking force to each of the plurality of wheels by supplying hydraulic fluid are further provided, and the control unit includes a first non-braking mode and a second non-braking mode as control modes in a non-braking state without operation input. The control mode is set to select one of a plurality of control modes including a braking mode, and the first non-braking mode is selected when an abnormality is detected or the detection of the abnormality is not completed. This is a control mode that secures a hydraulic fluid flow path from the master cylinder to the wheel cylinder so that a braking force is mechanically generated in response to an input. It is confirmed that no abnormality is detected in the second non-braking mode. The control mode may be selected when

  According to this aspect, the control freedom can be improved by setting a plurality of control modes in the non-braking state. In particular, the developer's design freedom can be improved. Further, in the first non-braking mode, the generation of the braking force according to the operation input by the driver is ensured, and fail safe is realized. For this reason, for example, by setting the second non-braking mode appropriately different from the first non-braking mode, it is possible to achieve both fail-safe and improved design freedom.

  The hydraulic pressure source further pressurizes the hydraulic fluid independently from the operation input, and the control unit supplies the hydraulic fluid from the hydraulic pressure source to the wheel cylinder and the hydraulic fluid from the master cylinder to the wheel cylinder. The second braking mode is set to select one of a plurality of control modes including the second braking mode to be supplied, and the second braking mode is set to close the simulator cut valve, and the first braking mode is set. The mode may be set so that the closed state of the simulator cut valve is continued when the control mode is changed from the second braking mode to the first braking mode.

  According to this aspect, the control mode is set so that the closed state of the simulator cut valve is maintained when the hydraulic fluid supply source is switched from the master cylinder to another hydraulic pressure source. While the amount of hydraulic fluid stored in the master cylinder is usually relatively limited, other hydraulic pressure sources, such as accumulators, that pressurize the hydraulic fluid independently of operation inputs can supply the amount of hydraulic fluid that can be supplied. Usually more than. For this reason, when it is necessary to sufficiently supply the hydraulic fluid, for example, when performing ABS control, it is preferable to switch the supply source of the hydraulic fluid from the master cylinder to another hydraulic pressure source. By maintaining the closed state of the simulator cut valve at the time of such switching, it is possible to prevent the hydraulic fluid from flowing from the master cylinder to the stroke simulator and to prevent the pedal from entering.

  The simulator cut valve is set to be opened in the second non-braking mode, and in the first braking mode, the simulator cut valve is set to be kept open and closed in the control mode before the change. Also good.

  For example, when it is confirmed that no abnormality is detected in the system and control is performed by so-called brake-by-wire, the control mode is switched between the first braking mode and the second non-braking mode depending on the presence or absence of a braking request. become. According to this aspect, when the control mode is switched between the second non-braking mode and the first braking mode, the simulator cut valve is continuously opened. Therefore, the simulator cut valve is continuously opened, and the opening / closing operation frequency of the simulator cut valve can be reduced. By reducing the operation frequency of the simulator cut valve, it is possible to reduce the frequency of operation noise generation and extend the useful life of the valve.

  The simulator cut valve is a normally-closed electromagnetic control valve that is opened by energizing a specified control current. The simulator cut valve is set to be closed in the second non-braking mode, and is changed in the first braking mode. The valve may be set to be opened when the previous control mode is the second non-braking mode. As described above, in the second non-braking mode, the power consumption of the normally-closed simulator cut valve can be reduced by closing the simulator cut valve.

  The simulator cut valve may be set so that the open / close state in the control mode before the change is continued in the second non-braking mode. Thus, in the second non-braking mode, the operation state of the simulator cut valve is reduced by continuing the open / close state in the control mode before the change.

  According to the present invention, it is possible to realize a good brake operation feeling.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a system diagram showing a brake control device 20 according to an embodiment of the present invention. A brake control device 20 shown in the figure constitutes an electronically controlled brake system (ECB) for a vehicle, and controls braking force applied to four wheels provided on the vehicle. The brake control device 20 according to the present embodiment is mounted on, for example, a hybrid vehicle that includes an electric motor and an internal combustion engine as a travel drive source. In such a hybrid vehicle, each of regenerative braking that brakes the vehicle by regenerating kinetic energy of the vehicle into electric energy and hydraulic braking by the brake control device 20 can be used for braking the vehicle. The vehicle in the present embodiment can execute brake regenerative cooperative control that generates a desired braking force by using both the regenerative braking and the hydraulic braking together.

  As shown in FIG. 1, the brake control device 20 includes disc brake units 21FR, 21FL, 21RR and 21RL provided for each wheel, a master cylinder unit 27, a power hydraulic pressure source 30, a hydraulic pressure, Actuator 40.

  Disc brake units 21FR, 21FL, 21RR, and 21RL apply braking force to the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel of the vehicle, respectively. The master cylinder unit 27 as the manual hydraulic pressure source in the present embodiment sends the brake fluid pressurized according to the amount of operation by the driver of the brake pedal 24 as the brake operation member to the disc brake units 21FR to 21RL. To do. The power hydraulic pressure source 30 can send the brake fluid as the working fluid pressurized by the power supply to the disc brake units 21FR to 21RL independently from the operation of the brake pedal 24 by the driver. is there. The hydraulic actuator 40 appropriately adjusts the hydraulic pressure of the brake fluid supplied from the power hydraulic pressure source 30 or the master cylinder unit 27 and sends it to the disc brake units 21FR to 21RL. Thereby, the braking force with respect to each wheel by hydraulic braking is adjusted.

  Each of the disc brake units 21FR to 21RL, the master cylinder unit 27, the power hydraulic pressure source 30, and the hydraulic actuator 40 will be described in more detail below. Each of the disc brake units 21FR to 21RL includes a brake disc 22 and wheel cylinders 23FR to 23RL incorporated in the brake caliper, respectively. The wheel cylinders 23FR to 23RL are connected to the hydraulic actuator 40 via different fluid passages. Hereinafter, the wheel cylinders 23FR to 23RL are collectively referred to as “wheel cylinders 23” as appropriate.

  In the disc brake units 21FR to 21RL, when brake fluid is supplied to the wheel cylinder 23 from the hydraulic actuator 40, a brake pad as a friction member is pressed against the brake disc 22 that rotates together with the wheel. Thereby, a braking force is applied to each wheel. In the present embodiment, the disc brake units 21FR to 21RL are used, but other braking force applying mechanisms including a wheel cylinder 23 such as a drum brake may be used.

  In this embodiment, the master cylinder unit 27 is a master cylinder with a hydraulic booster, and includes a hydraulic booster 31, a master cylinder 32, a regulator 33, and a reservoir. Input from the driver to the brake pedal 24 is mechanically transmitted to pressurize the brake fluid of the master cylinder 32. The hydraulic booster 31 is connected to the brake pedal 24, amplifies the pedal effort applied to the brake pedal 24, and transmits it to the master cylinder 32. When the brake fluid is supplied from the power hydraulic pressure source 30 to the hydraulic pressure booster 31 via the regulator 33, the pedal effort is amplified. The master cylinder 32 generates a master cylinder pressure having a predetermined boost ratio with respect to the pedal effort.

  A reservoir 34 for storing brake fluid is disposed above the master cylinder 32 and the regulator 33. The master cylinder 32 communicates with the reservoir 34 when the depression of the brake pedal 24 is released. On the other hand, the regulator 33 is in communication with both the reservoir 34 and the accumulator 35 of the power hydraulic pressure source 30, and the reservoir 34 is used as a low pressure source, the accumulator 35 is used as a high pressure source, and the hydraulic pressure is approximately equal to the master cylinder pressure. Is generated. Hereinafter, the hydraulic pressure in the regulator 33 is appropriately referred to as “regulator pressure”. The master cylinder pressure and the regulator pressure do not need to be exactly the same pressure. For example, the master cylinder unit 27 can be designed so that the regulator pressure is slightly higher.

  The power hydraulic pressure source 30 includes an accumulator 35 and a pump 36. The accumulator 35 converts the pressure energy of the brake fluid boosted by the pump 36 into the pressure energy of an enclosed gas such as nitrogen, for example, about 14 to 22 MPa and stores it. The pump 36 has a motor 36 a as a drive source, and its suction port is connected to the reservoir 34, while its discharge port is connected to the accumulator 35. The accumulator 35 is also connected to a relief valve 35 a provided in the master cylinder unit 27. When the pressure of the brake fluid in the accumulator 35 increases abnormally to about 25 MPa, for example, the relief valve 35 a is opened, and the high-pressure brake fluid is returned to the reservoir 34.

  As described above, the brake control device 20 includes the master cylinder 32, the regulator 33, and the accumulator 35 as a supply source of brake fluid to the wheel cylinder 23. A master pipe 37 is connected to the master cylinder 32, a regulator pipe 38 is connected to the regulator 33, and an accumulator pipe 39 is connected to the accumulator 35. These master pipe 37, regulator pipe 38 and accumulator pipe 39 are each connected to a hydraulic actuator 40.

  The hydraulic actuator 40 includes an actuator block in which a plurality of flow paths are formed, and a plurality of electromagnetic control valves. The flow paths formed in the actuator block include individual flow paths 41, 42, 43 and 44 and a main flow path 45. The individual flow paths 41 to 44 are respectively branched from the main flow path 45 and connected to the wheel cylinders 23FR, 23FL, 23RR, 23RL of the corresponding disc brake units 21FR, 21FL, 21RR, 21RL. Thereby, each wheel cylinder 23 can communicate with the main flow path 45.

  In addition, ABS holding valves 51, 52, 53 and 54 are provided in the middle of the individual flow paths 41, 42, 43 and 44. Each of the ABS holding valves 51 to 54 has a solenoid and a spring that are ON / OFF controlled, and both are normally open electromagnetic control valves that are opened when the solenoid is in a non-energized state. Each of the ABS holding valves 51 to 54 in the opened state can distribute the brake fluid in both directions. That is, the brake fluid can flow from the main flow path 45 to the wheel cylinder 23, and conversely, the brake fluid can also flow from the wheel cylinder 23 to the main flow path 45. When the solenoid is energized and the ABS holding valves 51 to 54 are closed, the flow of brake fluid in the individual flow paths 41 to 44 is blocked.

  Further, the wheel cylinder 23 is connected to the reservoir channel 55 via pressure reducing channels 46, 47, 48 and 49 connected to the individual channels 41 to 44, respectively. ABS decompression valves 56, 57, 58 and 59 are provided in the middle of the decompression channels 46, 47, 48 and 49. Each of the ABS pressure reducing valves 56 to 59 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the ABS pressure reducing valves 56 to 59 are closed, the flow of brake fluid in the pressure reducing flow paths 46 to 49 is blocked. When the solenoid is energized and the ABS pressure reducing valves 56 to 59 are opened, the brake fluid is allowed to flow through the pressure reducing flow paths 46 to 49, and the brake fluid flows from the wheel cylinder 23 to the pressure reducing flow paths 46 to 49 and It returns to the reservoir 34 via the reservoir channel 55. The reservoir channel 55 is connected to the reservoir 34 of the master cylinder unit 27 via a reservoir pipe 77.

  The main channel 45 has a separation valve 60 in the middle. By this separation valve 60, the main channel 45 is divided into a first channel 45 a connected to the individual channels 41 and 42 and a second channel 45 b connected to the individual channels 43 and 44. The first flow path 45a is connected to the front wheel wheel cylinders 23FR and 23FL via the individual flow paths 41 and 42, and the second flow path 45b is connected to the rear wheel wheel cylinder via the individual flow paths 43 and 44. Connected to 23RR and 23RL.

  The separation valve 60 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the separation valve 60 is in the closed state, the flow of brake fluid in the main flow path 45 is blocked. When the solenoid is energized and the separation valve 60 is opened, the brake fluid can be circulated bidirectionally between the first flow path 45a and the second flow path 45b.

  In the hydraulic actuator 40, a master channel 61 and a regulator channel 62 communicating with the main channel 45 are formed. More specifically, the master channel 61 is connected to the first channel 45 a of the main channel 45, and the regulator channel 62 is connected to the second channel 45 b of the main channel 45. The master channel 61 is connected to a master pipe 37 that communicates with the master cylinder 32. The regulator channel 62 is connected to a regulator pipe 38 that communicates with the regulator 33.

  The master channel 61 has a master cut valve 64 in the middle. The master cut valve 64 is provided on the brake fluid supply path from the master cylinder 32 to each wheel cylinder 23. The master cut valve 64 has a solenoid and a spring that are ON / OFF-controlled, and the valve closing state is guaranteed by the electromagnetic force generated by the solenoid when supplied with a prescribed control current, so that the solenoid is in a non-energized state. It is a normally open electromagnetic control valve that is opened in some cases. The master cut valve 64 in the opened state can cause the brake fluid to flow in both directions between the master cylinder 32 and the first flow path 45 a of the main flow path 45. When a prescribed control current is applied to the solenoid and the master cut valve 64 is closed, the flow of brake fluid in the master flow path 61 is interrupted.

  A stroke simulator 69 is connected to the master channel 61 via a simulator cut valve 68 on the upstream side of the master cut valve 64. That is, the simulator cut valve 68 is provided in a flow path connecting the master cylinder 32 and the stroke simulator 69. The simulator cut valve 68 has a solenoid and a spring that are ON / OFF controlled, and the valve opening state is guaranteed by the electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is in a non-energized state. It is a normally closed electromagnetic control valve that is closed in some cases. When the simulator cut valve 68 is closed, the flow of brake fluid between the master flow path 61 and the stroke simulator 69 is blocked. When the solenoid is energized and the simulator cut valve 68 is opened, the brake fluid can be circulated bidirectionally between the master cylinder 32 and the stroke simulator 69.

  The stroke simulator 69 includes a plurality of pistons and springs, and creates a reaction force corresponding to the depression force of the brake pedal 24 by the driver when the simulator cut valve 68 is opened. As the stroke simulator 69, in order to improve the feeling of brake operation by the driver, it is preferable to employ one having a multistage spring characteristic.

  The regulator flow path 62 has a regulator cut valve 65 in the middle. The regulator cut valve 65 is provided on the brake fluid supply path from the regulator 33 to each wheel cylinder 23. The regulator cut valve 65 also has a solenoid and a spring that are controlled to be turned on and off, and the closed state is guaranteed by the electromagnetic force generated by the solenoid when supplied with a prescribed control current, so that the solenoid is turned off. It is a normally open electromagnetic control valve that is opened in some cases. The regulator cut valve 65 that has been opened can cause the brake fluid to flow in both directions between the regulator 33 and the second flow path 45 b of the main flow path 45. When the solenoid is energized and the regulator cut valve 65 is closed, the flow of brake fluid in the regulator flow path 62 is blocked.

  In the hydraulic actuator 40, an accumulator channel 63 is also formed in addition to the master channel 61 and the regulator channel 62. One end of the accumulator channel 63 is connected to the second channel 45 b of the main channel 45, and the other end is connected to an accumulator pipe 39 that communicates with the accumulator 35.

  The accumulator flow path 63 has a pressure-increasing linear control valve 66 in the middle. Further, the accumulator channel 63 and the second channel 45 b of the main channel 45 are connected to the reservoir channel 55 via the pressure-reducing linear control valve 67. The pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 each have a linear solenoid and a spring, and both are normally closed electromagnetic control valves that are closed when the solenoid is in a non-energized state. In the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67, the opening degree of the valve is adjusted in proportion to the current supplied to each solenoid.

  The pressure-increasing linear control valve 66 is provided as a common pressure-increasing control valve for each of the wheel cylinders 23 provided corresponding to each wheel. Similarly, the pressure reducing linear control valve 67 is provided as a pressure reducing control valve common to the wheel cylinders 23. That is, in this embodiment, the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 are a pair of common control valves that control the supply and discharge of the working fluid sent from the power hydraulic pressure source 30 to each wheel cylinder 23. It is provided as. If the pressure-increasing linear control valve 66 and the like are made common to each wheel cylinder 23 in this way, it is preferable from the viewpoint of cost as compared with the case where a linear control valve is provided for each wheel cylinder 23.

  Here, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 corresponds to the differential pressure between the pressure of the brake fluid in the accumulator 35 and the pressure of the brake fluid in the main flow path 45, and the inlet / outlet of the pressure-reducing linear control valve 67. The pressure difference therebetween corresponds to the pressure difference between the brake fluid pressure in the main flow path 45 and the brake fluid pressure in the reservoir 34. Further, the electromagnetic driving force according to the power supplied to the linear solenoid of the pressure increasing linear control valve 66 and the pressure reducing linear control valve 67 is F1, the spring biasing force is F2, and the pressure increasing linear control valve 66 and the pressure reducing linear control valve are Assuming that the differential pressure acting force according to the differential pressure between the inlet / outlet of 67 is F3, the relationship of F1 + F3 = F2 is established. Therefore, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 is controlled by continuously controlling the power supplied to the linear solenoids of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. can do.

  In the brake control device 20, the power hydraulic pressure source 30 and the hydraulic actuator 40 are controlled by a brake ECU 70 as a control unit in the present embodiment. The brake ECU 70 is configured as a microprocessor including a CPU, and includes a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, a communication port, and the like in addition to the CPU. The brake ECU 70 can communicate with a host hybrid ECU (not shown) and the like, and based on control signals from the hybrid ECU and signals from various sensors, the pump 36 of the power hydraulic pressure source 30 and the hydraulic pressure The electromagnetic control valves 51 to 54, 56 to 59, 60, and 64 to 68 constituting the actuator 40 are controlled.

  Further, a regulator pressure sensor 71, an accumulator pressure sensor 72, and a control pressure sensor 73 are connected to the brake ECU 70. The regulator pressure sensor 71 detects the pressure of the brake fluid in the regulator flow path 62 on the upstream side of the regulator cut valve 65, that is, the regulator pressure, and gives a signal indicating the detected value to the brake ECU 70. The accumulator pressure sensor 72 detects the pressure of the brake fluid in the accumulator flow path 63, that is, the accumulator pressure on the upstream side of the pressure increasing linear control valve 66, and gives a signal indicating the detected value to the brake ECU 70. The control pressure sensor 73 detects the pressure of the brake fluid in the first flow path 45a of the main flow path 45, and gives a signal indicating the detected value to the brake ECU 70. The detection values of the pressure sensors 71 to 73 are sequentially given to the brake ECU 70 every predetermined time, and are stored and held in a predetermined storage area of the brake ECU 70 by a predetermined amount.

  When the separation valve 60 is opened and the first flow path 45 a and the second flow path 45 b of the main flow path 45 communicate with each other, the output value of the control pressure sensor 73 is the low pressure of the pressure-increasing linear control valve 66. This indicates the hydraulic pressure on the high pressure side of the pressure-reducing linear control valve 67 and the output value can be used to control the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. When the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are closed and the master cut valve 64 is opened, the output value of the control pressure sensor 73 indicates the master cylinder pressure. Further, the separation valve 60 is opened so that the first flow path 45a and the second flow path 45b of the main flow path 45 communicate with each other, and the ABS holding valves 51 to 54 are opened, while the ABS pressure reducing valves 56 are opened. When? 59 is closed, the output value of the control pressure sensor 73 indicates the working fluid pressure acting on each wheel cylinder 23, i.e., the wheel cylinder pressure.

  Further, the sensor connected to the brake ECU 70 includes a stroke sensor 25 provided on the brake pedal 24. The stroke sensor 25 detects a pedal stroke as an operation amount of the brake pedal 24 and gives a signal indicating the detected value to the brake ECU 70. The output value of the stroke sensor 25 is also sequentially given to the brake ECU 70 every predetermined time, and is stored and held in a predetermined storage area of the brake ECU 70 by a predetermined amount. A brake operation state detection unit other than the stroke sensor 25 may be provided in addition to the stroke sensor 25 or in place of the stroke sensor 25 and connected to the brake ECU 70. Examples of the brake operation state detection means include a pedal depression force sensor that detects an operation force of the brake pedal 24 and a brake switch that detects that the brake pedal 24 is depressed.

  The brake control device 20 configured as described above can execute brake regeneration cooperative control. The brake control device 20 starts braking in response to a braking request. The braking request is generated when a braking force should be applied to the vehicle, for example, when the driver operates the brake pedal 24. In response to the braking request, the brake ECU 70 calculates a required braking force, and calculates a required hydraulic braking force that is a braking force to be generated by the brake control device 20 by subtracting the braking force due to regeneration from the required braking force. Here, the braking force by regeneration is supplied to the brake control device 20 from the hybrid ECU. Then, the brake ECU 70 calculates the target hydraulic pressure of each wheel cylinder 23FR to 23RL based on the calculated required hydraulic braking force. The brake ECU 70 determines the value of the control current supplied to the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 based on the feedback control law so that the wheel cylinder pressure becomes the target hydraulic pressure.

  As a result, in the brake control device 20, the brake fluid is supplied from the power hydraulic pressure source 30 to the wheel cylinders 23 via the pressure-increasing linear control valve 66, and braking force is applied to the wheels. Further, brake fluid is discharged from each wheel cylinder 23 through the pressure-reducing linear control valve 67 as necessary, and the braking force applied to the wheel is adjusted. In the present embodiment, a wheel cylinder pressure control system is configured including the power hydraulic pressure source 30, the pressure-increasing linear control valve 66, the pressure-decreasing linear control valve 67, and the like. A so-called brake-by-wire braking force control is performed by the wheel cylinder pressure control system. The wheel cylinder pressure control system is provided in parallel to the brake fluid supply path from the master cylinder unit 27 to the wheel cylinder 23.

  At this time, the brake ECU 70 closes the regulator cut valve 65 and the master cut valve 64 so that the brake fluid sent from the regulator 33 and the master cylinder 32 is not supplied to the wheel cylinder 23. During the brake regeneration cooperative control, a differential pressure corresponding to the magnitude of the regenerative braking force acts between the upstream and downstream of the regulator cut valve 65 and the master cut valve 64.

  The brake control device 20 according to the present embodiment can naturally control the braking force by the wheel cylinder pressure control system even when the required braking force is provided only by the hydraulic braking force without using the regenerative braking force. . Regardless of whether or not the brake regeneration cooperative control is executed, the control mode for controlling the braking force by the wheel cylinder pressure control system will be appropriately referred to as a “linear control mode” below. Or it may be called control by brake-by-wire.

  When the required braking force is generated only by the hydraulic braking force in the linear control mode, the brake ECU 70 controls the regulator pressure or the master cylinder pressure as the target pressure of the wheel cylinder pressure. Therefore, in this case, it is not always necessary to supply the brake fluid to the wheel cylinder 23 by the wheel cylinder pressure control system. This is because the required braking force can be generated naturally if the master cylinder pressure or the regulator pressure pressurized according to the operation of the brake pedal by the driver is directly introduced into the wheel cylinder.

  For this reason, the brake control device 20 may supply brake fluid from the regulator 33 to each wheel cylinder 23 when the regenerative braking force is not used, for example, when the vehicle is stopped. Hereinafter, the control mode in which the brake fluid is supplied from the regulator 33 to each wheel cylinder 23 is referred to as a regulator mode. That is, the brake ECU 70 may switch from the linear control mode to the regulator mode while the vehicle is stopped to generate a braking force. If the control mode is switched when the vehicle is stopped, it is preferable in that the control mode can be switched with relatively simple control. Alternatively, more practically, the brake ECU 70 may switch the control mode from the linear control mode to the regulator mode when the regenerative braking is stopped because the vehicle speed has sufficiently decreased due to braking.

  In the regulator mode, the brake ECU 70 opens the regulator cut valve 65 and the separation valve 60 and closes the master cut valve 64. The pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are stopped and closed. As a result, brake fluid is supplied from the regulator 33 to each wheel cylinder 23, and braking force is applied to each wheel by the regulator pressure. Since the power hydraulic pressure source 30 is connected to the regulator 33 on the high pressure side, it is preferable in that the braking force can be generated by utilizing the accumulated pressure in the power hydraulic pressure source 30.

  Thus, in the regulator mode, the brake ECU 70 stops supplying the control current to the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 and closes both linear control valves. For this reason, it becomes possible to reduce the operation frequency of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67, and the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 can be used for a long period of time. . That is, the service life of the pressure increasing linear control valve 66 and the pressure reducing linear control valve 67 can be improved.

  During the control in the linear control mode, the wheel cylinder pressure may deviate from the target hydraulic pressure due to, for example, occurrence of an abnormality such as leakage of hydraulic fluid from any location. The brake ECU 70 periodically determines the presence or absence of a wheel cylinder pressure response abnormality based on, for example, a measurement value of the control pressure sensor 73. The brake ECU 70 determines that there is an abnormality in the control response of the wheel cylinder pressure when, for example, the amount of deviation of the measured value of the wheel cylinder pressure from the target hydraulic pressure exceeds the reference. When it is determined that the wheel cylinder pressure control response is abnormal, the brake ECU 70 stops the linear control mode and switches the control mode to the manual brake mode. Similarly, the brake ECU 70 switches the control mode to the manual brake mode when an abnormality is detected in the regulator mode. In the manual brake mode, the driver's input to the brake pedal 24 is converted into hydraulic pressure and mechanically transmitted to the wheel cylinder 23 to apply braking force to the wheels. The manual brake mode has a role as a control mode for backup from the viewpoint of fail-safe.

  An example of the control mode for backup is the hydro booster mode. The hydro booster mode is a control mode in which a hydraulic fluid flow path from the master cylinder 32 to the wheel cylinder 23 is secured so that a braking force is mechanically generated in response to an operation input to the brake operation member. In the hydro booster mode, the brake ECU 70 stops supplying control current to all the electromagnetic control valves. Therefore, the normally open master cut valve 64 and the regulator cut valve 65 are opened, and the normally closed separation valve 60 and the simulator cut valve 68 are closed. The pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are stopped and closed.

  As a result, the brake fluid supply path is separated into two systems, the master cylinder side and the regulator side. The master cylinder pressure is transmitted to the wheel cylinders 23FR and 23FL for the front wheels, and the regulator pressure is transmitted to the wheel cylinders 23RR and 23RL for the rear wheels. The delivery destination of the working fluid from the master cylinder 32 is switched from the stroke simulator 69 to the wheel cylinders 23FR and 23FL for the front wheels. Further, since the hydraulic booster 31 is a mechanism that mechanically amplifies the pedal depression force, the hydraulic booster 31 continues to function even when the control current to each electromagnetic control valve is stopped by shifting to the hydro booster mode. According to the hydro booster mode, even if there is no energization to each electromagnetic control valve due to an abnormality in the control system, it is excellent in fail-safety in that braking force can be generated using a hydraulic booster. Yes.

  For convenience, the system on the master cylinder side in the hydro booster mode is hereinafter referred to as a master system, and the system on the regulator side is referred to as a regulator system. In the present embodiment, the hydraulic fluid is supplied to the front wheel side by the master system and to the rear wheel side by the regulator system in the hydro booster mode, and therefore, the master system and the regulator system may be referred to as a front system and a rear system, respectively. .

  Further, in the present embodiment, two control modes of the first non-braking mode and the second non-braking mode are set during non-braking when the driver does not perform a braking operation. In the present embodiment, the first non-braking mode is the hydro booster mode, which is a control mode in which the control current to each control valve is turned off as in the above-described hydro booster mode during braking. The brake ECU 70 selects the first non-braking mode, that is, the hydro booster mode during non-braking when an abnormality is detected in the brake system.

  The brake ECU 70 selects the second non-braking mode when it is confirmed that no abnormality is detected. Hereinafter, the second non-braking mode is referred to as an out-of-control mode. For example, the brake ECU 70 selects the out-of-control mode during non-braking when no abnormality is detected in the initial inspection that is performed when the vehicle is started. In this initial inspection, for example, continuity confirmation of each control valve and operation check of each sensor are performed. The brake ECU 70 selects the first non-braking mode during non-braking when the initial inspection is not completed.

  As described above, by setting a plurality of control modes in the non-braking state, the degree of freedom of control can be improved. In particular, the developer's design freedom can be improved. Further, in the first non-braking mode, that is, the hydro booster mode, the generation of the braking force according to the operation input by the driver is ensured, and fail safe is realized. For this reason, the setting of the open / closed state of each control valve in the out-of-control mode is appropriately set differently from the hydro booster mode, so that both fail-safe and improvement in design freedom can be achieved. In addition, it is also possible to set the open / closed state of the non-control mode to be the same as the hydro booster mode. Three or more control modes in the non-braking state may be set.

  On the other hand, as described above, three control modes are set as the control mode during braking: a linear control mode, a regulator mode, and a hydro booster mode. The linear control mode is a control mode for supplying brake fluid from the power hydraulic pressure source 30 to the wheel cylinder 23, and corresponds to the first braking mode. The regulator mode also corresponds to the first braking mode. This is because the regulator mode is a control mode in which brake fluid is supplied to the wheel cylinder 23 from the regulator 33 using the power hydraulic pressure source 30 as a high pressure source. The hydro booster mode corresponds to the second braking mode.

  The hydro booster mode is selected not only when an abnormality is detected, but also when the detection of the abnormality is not completed. The case where the abnormality detection is not completed is, for example, until the initial inspection executed by the brake ECU 70 at the time of starting the vehicle is completed. However, depending on the situation, it may be desirable to change the control mode to the linear control mode or the regulator mode even when the initial inspection has not been completed and the presence or absence of abnormality has not been determined. For example, when ABS control is executed. Execution of the ABS control is assumed, for example, when the vehicle has started on a hill or the like with the brake pedal depressed while the initial inspection is not completed immediately after the vehicle IG-ON.

  When ABS control is executed, it is desirable that there is a sufficient margin in the amount of hydraulic fluid that can be supplied to the wheel cylinder 23 in order to optimally control the braking force of each wheel and minimize the stop distance. In the hydro booster mode, the amount of liquid that can be supplied from the master cylinder 32 is limited to the amount of liquid stored in the master cylinder 32 with respect to the front system. On the other hand, in the linear mode and the regulator mode, the brake fluid is supplied from the power hydraulic pressure source 30, so that a larger amount of brake fluid can be supplied smoothly than in the hydro booster mode. In the present embodiment, the regulator mode is selected during execution of the ABS control.

  In the hydro booster mode, the simulator cut valve 68 is closed and the stroke simulator 69 is separated from the master cylinder 32 in order to effectively use the amount of liquid stored in the master cylinder 32 for braking. On the other hand, in the linear control mode and the regulator mode, it is desirable to connect the stroke simulator 69 to the master cylinder 32 in order to achieve an appropriate brake feeling. Therefore, when the open / close state of the simulator cut valve 68 in each control mode is uniquely set for each control mode in accordance with the normally assumed use environment, the valve is closed in the hydro booster mode, the linear control mode and the regulator. In the mode, the valve is set to open.

  Consider a case where the control mode is changed from the hydro booster mode to the linear control mode or the regulator mode during the brake operation under this setting. When the open / close state of the simulator cut valve 68 is uniquely set for each control mode, if the simulator cut valve 68 is set to be opened in the changed control mode, the open / close state before the change is set. It will be opened regardless of the. Therefore, the simulator cut valve 68 is opened together with the control mode change according to the setting. As a result, the brake fluid starts to flow from the master cylinder 32 to the stroke simulator 69 in response to the change to the linear control mode or the regulator mode. A considerable amount of brake fluid flows out of the master cylinder 32 in accordance with the amount of liquid that can be stored in the stroke simulator 69. As a result, the brake pedal 24 may be greatly displaced, and the brake pedal 24 may enter.

  Therefore, in the present embodiment, when changing the control mode while the brake operation input is being made, the brake ECU 70 changes to the destination to which hydraulic fluid is not supplied from the master cylinder in the control mode before the change. Control is performed so that the hydraulic fluid is not continuously supplied even in the later control mode. For this purpose, the control valve open / close state is not uniquely set for each control mode, but the control valve open / close state in the control mode after the change is made different according to the control mode before the change.

  Specifically, the hydro booster mode is set so that the simulator cut valve 68 is closed. The linear control mode and the regulator mode are set so that the closed state of the simulator cut valve 68 is maintained when the control mode before the change is the hydro booster mode in the change of the control mode during the brake operation. Thereby, the hydraulic fluid outflow to the stroke simulator 69 triggered by the control mode change during the brake operation can be prevented. Therefore, entry of the brake pedal 24 can be prevented.

  FIG. 2 is a diagram illustrating an example of setting the open / close state of each control valve according to the present embodiment. FIG. 2 shows the open / close states of the regulator cut valve 65, the master cut valve 64, the separation valve 60, and the simulator cut valve 68 in each control mode. In order to facilitate understanding, the energized state of each control valve is indicated as ON or OFF together with the open / closed state. Moreover, the control state in each control mode of the pressure increase linear control valve 66 and the pressure reduction linear control valve 67 is shown. Since the open / close states of the control valves other than the simulator cut valve 68 have already been described, the following description will focus on the open / close state of the simulator cut valve 68.

  As shown in FIG. 2, the simulator cut valve 68 is set to continue the open / close state in the control mode before the change to the linear control mode in the linear control mode. Similarly, in the regulator mode, the simulator cut valve 68 is set to continue the open / close state of the control mode before the change to the regulator mode. It should be noted that the simulator cut valve 68 may be set to be opened when there is no open / closed state before the change, for example, at the beginning of the system.

  By setting the open / close state in this way, for example, when the control mode is changed from the hydro booster mode to the linear control mode or the regulator mode, the simulator cut valve 68 is closed in the hydro booster mode, so the linear The simulator cut valve 68 is continuously closed even in the control mode or the regulator mode. Therefore, the hydraulic fluid is prevented from flowing out from the master cylinder to the stroke simulator when the control mode is changed. For this reason, the brake pedal can be prevented from entering. In particular, the brake pedal can be prevented from entering when the execution of the ABS control is started in the hydro booster mode and the mode is shifted to the regulator mode.

  Further, even when the control mode is switched from the linear control mode to the regulator mode as in a normal stop during regenerative cooperative control, the open / close state of the simulator cut valve 68 in the control mode before the change is continued. Therefore, even if the control mode is switched, the connection state between the master cylinder 32 and the stroke simulator 69 is continued, and the brake feeling is maintained. In this manner, it is possible to achieve both prevention of pedal entry when the control mode is changed from the hydro booster mode during braking and ensuring brake feeling during normal operation.

  Further, as shown in FIG. 2, the simulator cut valve 68 is set to be opened in the non-control mode, which is the control mode in the normal non-braking state. During normal operation, the brake ECU 70 selects the linear control mode or the regulator mode during braking, and selects the non-control mode during non-braking. For this reason, the simulator cut valve 68 continues the valve open state. Therefore, according to this embodiment, the opening / closing operation frequency of the simulator cut valve 68 can be reduced. By reducing the operation frequency of the simulator cut valve 68, it is possible to reduce the frequency of operation noise generation and lengthen the service life of the valve.

  Next, a first modification of the present embodiment will be described. FIG. 3 is a diagram illustrating an example of setting of the open / close state of each control valve according to the first modification of the present embodiment. In FIG. 3, the setting of the open / close state of the simulator cut valve 68 in the linear control mode, the regulator mode, and the non-control mode is different from that in FIG. Description of common parts is omitted as appropriate. In FIG. 3, for the sake of convenience, the hydro booster mode is indicated as “HB”, the linear control mode as “LNR”, and the regulator mode as “REG”. The same notation is used as appropriate in the following figures.

  As shown in FIG. 3, in the first modification, the open / close state of the simulator cut valve 68 in the linear control mode and the regulator mode is set to be different depending on the control mode before the change. When the control mode before the change is the hydro booster mode, the valve is in the closed state, and in the non-control mode, the valve is in the open state. When the control mode before the change is the linear control mode or the regulator mode, the open / close state in the control mode before the change is set to be continued. Thus, the open / close states of the linear control mode and the regulator mode are set to be the same. In the non-control mode, the simulator cut valve 68 is set to a closed state. In the first modification, the out-of-control mode and the hydro booster mode are set to the same open / close state.

  In this way, when the brake system is normal, the simulator cut valve 68 is opened during braking, and is closed during non-braking. Since the simulator cut valve 68 is a normally closed electromagnetic control valve that is opened when a prescribed control current is applied, the power consumption of the valve can be reduced by closing the valve when the brake is not braked.

  Furthermore, the 2nd modification of this embodiment is demonstrated. FIG. 4 is a diagram illustrating an example of setting of the open / close state of each control valve according to the second modification of the present embodiment. In the second modification, the open / close state of the simulator cut valve 68 in the out-of-control mode is different from that in the first modification. As shown in FIG. 4, the open / close state of the simulator cut valve 68 in the non-control mode is set to continue the open / close state in the control mode before the change. Other points are common to the first modification. In this way, since the open / close state in the control mode before the change is continued in the non-control mode, the operation frequency of the simulator cut valve 68 can be reduced.

  Subsequently, an operation example of the simulator cut valve 68 in the above-described embodiment and each modification will be described with reference to FIGS. 5 and 6. 5 and 6, the uppermost row shows the control mode. The second row from the top indicates whether braking is on or off, that is, whether the braking state or the non-braking state. A in the third stage shows the open / close state of the simulator cut valve 68 according to the present embodiment. B in the fourth stage shows the open / close state of the simulator cut valve 68 according to the first modification. C in the fifth stage shows the open / close state of the simulator cut valve 68 according to the first modification.

  FIG. 5 shows an operation example when an abnormality is detected during regenerative cooperative control and the mode is shifted to the hydro booster mode. It is assumed that an abnormality is detected during the second braking after the brake ECU 70 is activated. First, when the brake ECU 70 is activated, an initial inspection is performed in the hydro booster mode. When the initial inspection is completed without detecting any abnormality, the mode shifts to the out-of-control mode. In the first braking, the linear control mode or the regulator mode is selected. Specifically, the linear control mode is selected during regenerative cooperative control, and the regulator mode is selected while the vehicle is stopped. When the braking request is canceled, the mode shifts to the out-of-control mode. When the second braking is started, the linear control mode or the regulator mode is selected. In this example, an abnormality is detected during the second braking, and the mode is shifted to the hydro booster mode.

  In this situation example, in the present embodiment indicated by A in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. The simulator cut valve 68 is closed in the hydro booster mode selected when the brake ECU 70 is started, and is opened when the mode is shifted to the non-control mode. Once the simulator cut valve 68 is opened, the simulator cut valve 68 is kept open until the operation shifts to the hydro booster mode again due to abnormality detection. This is because the open / close state of the simulator cut valve 68 is set to be the open state in the non-control mode, and the state before the change is continued in the linear control mode and the regulator mode.

  In the first modification shown by B in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. The simulator cut valve 68 is opened in the linear control mode or the regulator mode, and is closed in other control modes. This is set so that the open / close state of the simulator cut valve 68 is in the closed state in the non-control mode, and in the linear control mode and the regulator mode, the open state is set when the control mode before the change is the non-control mode. Because.

  In the second modification shown by C in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. Since the state before the change is set to be continued in the non-control mode, the simulator cut valve 68 is closed until the first braking start after the brake ECU 70 is started. After the first braking start, the opening / closing state of the present embodiment shown by A in the figure is the same.

  In FIG. 5, the number of switching of the open / close state of the simulator cut valves 68 of A to C is 2 times for A, 4 times for B, and 2 times for C. Thus, it can be seen that the opening / closing frequency of the simulator cut valve 68 is reduced in the present embodiment and the second modification. Compared to the case where the simulator cut valve 68 is opened / closed every time switching between braking and non-braking conventionally, the frequency of opening / closing the simulator cut valve 68 is reduced in the present embodiment and the second modification.

  Further, it can be seen that the valve opening time, that is, the energization time of the simulator cut valve 68 is shortened in the order of A, C, B, that is, in this embodiment, the second modification, and the first modification. It turns out that the 1st modification is advantageous from a viewpoint of reduction of power consumption. In addition, the second modification example has a shorter energization time than the present embodiment, and it can be said that the reduction in switching frequency and the reduction in power consumption are compatible to some extent.

  FIG. 6 shows an operation example when the ABS control is executed during the initial inspection when the brake ECU 70 is activated. First, when the brake ECU 70 is activated, an initial inspection is performed in the hydro booster mode. Assume that ABS control is started before the completion of the initial inspection. The control mode is switched to the regulator mode or the linear control mode when the ABS control is started. When the ABS control is finished by the end of braking, the mode is shifted to the non-control mode. Here, it is assumed that the initial inspection is completed before the ABS control is completed. Therefore, the linear control mode or the regulator mode is selected during subsequent braking, and the non-control mode is selected during non-braking.

  In this situation example, in the present embodiment indicated by A in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. In the hydro booster mode when the brake ECU 70 is activated, the simulator cut valve 68 is closed. Even if the control mode is switched to the regulator mode or the linear control mode by starting the execution of the ABS control, the simulator cut valve 68 is continuously closed. When the ABS control is finished and the mode shifts to the out-of-control mode, the simulator cut valve 68 is opened, and the valve open state is continued thereafter. The reason why the simulator cut valve 68 is opened and closed in this way is that the open / closed state of the simulator cut valve 68 is set to continue in the linear control mode and the regulator mode, and is open in the non-control mode. is there.

  In the first modification shown by B in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. The simulator cut valve 68 is closed in the linear control mode or regulator mode during ABS control, while it is opened in the normal linear control mode or regulator mode. This is set so that the open / close state of the simulator cut valve 68 is closed when the control mode before the change is the hydro booster mode in the linear control mode and the regulator mode, and is opened when the control mode is the non-control mode. Because. In the non-control mode, the simulator cut valve 68 is closed by setting.

  In the second modification shown by C in the figure, the simulator cut valve 68 is opened and closed according to the open / close state setting shown in FIG. Since the state before the change is set to be continued in the non-control mode, the simulator cut valve 68 is closed until the first braking start after the end of the ABS control. After that, it becomes the same as the open / closed state of this embodiment shown by A in the figure.

  In FIG. 6, the number of switching of the open / close state of the simulator cut valves 68 of A to C is 1 for A, 2 for B, and 1 for C. Similar to the operation example shown in FIG. 5, it can be seen that the opening / closing frequency of the simulator cut valve 68 is reduced in the present embodiment and the second modification. Further, it can be seen that the valve opening time, that is, the energization time of the simulator cut valve 68 is shortened in the order of A, C, B, that is, in this embodiment, the second modification, and the first modification.

  According to the present embodiment, for example, when the control mode is switched from the hydro booster mode to the regulator mode or the linear control mode due to the start of execution of ABS control, the simulator cut valve 68 is continuously closed. By continuing the valve closing state in this manner, the brake pedal 24 can be prevented from entering.

It is a distribution diagram showing a brake control device concerning one embodiment of the present invention. It is a figure which shows an example of the setting of the open / close state of each control valve which concerns on this embodiment. It is a figure which shows an example of the setting of the open / close state of each control valve which concerns on the 1st modification of this embodiment. It is a figure which shows an example of the setting of the open / close state of each control valve which concerns on the 2nd modification of this embodiment. It is a figure which shows the operation example of the simulator cut valve in this embodiment and each modification. It is a figure which shows the operation example of the simulator cut valve in this embodiment and each modification.

Explanation of symbols

  20 brake control device, 23 wheel cylinder, 24 brake pedal, 27 master cylinder unit, 30 power hydraulic pressure source, 31 hydraulic pressure booster, 32 master cylinder, 33 regulator, 34 reservoir, 60 separation valve, 64 master cut valve, 65 regulator Cut valve, 66 Pressure increase linear control valve, 67 Pressure reduction linear control valve, 68 Simulator cut valve, 69 Stroke simulator, 70 Brake ECU, 71 Regulator pressure sensor, 72 Accumulator pressure sensor, 73 Control pressure sensor

Claims (6)

A brake operation member that receives an operation input by the driver;
A master cylinder that pressurizes the stored hydraulic fluid in response to the operation input;
A stroke simulator that generates a reaction force against the operation input by supplying hydraulic fluid from the master cylinder;
A simulator cut valve provided in the middle of a flow path connecting the master cylinder and the stroke simulator;
A control unit that selects one of a plurality of preset control modes and controls the simulator cut valve according to the selected control mode,
When the control unit changes the control mode while the brake operation member is being operated, and the control mode before the change is a control mode for closing the simulator cut valve, the control mode after the change However, the brake control device is characterized by continuously closing the simulator cut valve. A plurality of wheel cylinders for applying braking force to each of the plurality of wheels by supplying hydraulic fluid;
The control unit is set to select one of a plurality of control modes including a first non-braking mode and a second non-braking mode as a control mode in a non-braking state without the operation input,
The first non-braking mode is selected when an abnormality is detected or when the detection of the abnormality is not completed, and the master cylinder causes the braking force to be generated mechanically in response to the operation input. This is a control mode that secures the hydraulic fluid flow path to the wheel cylinder.
The brake control device according to claim 1, wherein the second non-braking mode is a control mode that is selected when it is confirmed that no abnormality is detected. A fluid pressure source for pressurizing the working fluid independently from the operation input;
The control unit includes a plurality of controls including a first braking mode for supplying hydraulic fluid from the hydraulic pressure source to the wheel cylinder and a second braking mode for supplying hydraulic fluid from the master cylinder to the wheel cylinder. Is set to select one of the modes,
The second braking mode is set so that the simulator cut valve is closed,
The first braking mode is set so that the closed state of the simulator cut valve is maintained when the control mode is changed from the second braking mode to the first braking mode. The brake control device according to claim 2, wherein   The simulator cut valve is set to be opened in the second non-braking mode, and in the first braking mode, the open / close state of the simulator cut valve in the control mode before the change is continued. The brake control device according to claim 3, wherein the brake control device is set.   The simulator cut valve is a normally-closed electromagnetic control valve that is opened by energizing a specified control current, and is set to be closed in the second non-braking mode. The brake control device according to claim 3, wherein the mode is set so that the valve is opened when the control mode before the change is the second non-braking mode.   The brake control device according to claim 3, wherein the simulator cut valve is set so that the open / close state in the control mode before the change is continued in the second non-braking mode.

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