Vehicle brake system

Abstract

To provide a brake control system for a vehicle in which: operation inspection of an upstream brake mechanism and a downstream brake mechanism are possible by use of a backup power source; and electric power supplied to the upstream brake mechanism from the backup power source is guaranteed when a main power source is turned defective during travelling of a vehicle.SOLUTION: Upstream backup power lines UBL1, UBL2 connect a backup power source 70 with an upstream brake mechanism 10. Downstream backup power lines LBL1, LBL2 include backup power cables 96, 98 and backup switches SW6, SW8. The backup power cables 96, 98 connect the backup power source 70 with a downstream brake mechanism 50. A switch operation part 80C executes a switch determination. The switch determination determines whether the backup switches SW6, SW8 can be switched from an OFF state to an ON state. The switch determination is executed when a vehicle stops and a travel control system turns to the OFF state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] Disclosed herein is a braking system for a vehicle. [Background technology]

[0002] Brake-by-wire is a known vehicle braking system. In a brake-by-wire system, the driver's brake pedal operation is converted into an electrical signal, which is then processed to control the brakes.

[0003] In such brake-by-wire systems, there are known examples in which the brake system is divided into an upstream brake mechanism and a downstream brake mechanism. For example, the upstream brake mechanism generates hydraulic pressure based on the amount of brake pedal operation. In the downstream brake mechanism, the hydraulic pressure generated by the upstream brake mechanism is distributed to each of the four wheels.

[0004] The upstream and downstream brake mechanisms are powered by the vehicle's main power supply. A power failure occurs when the power supply does not supply power normally or at all due to a hardware or software failure. To prepare for the failure of the main power supply, the vehicle is provided with a backup power supply.

[0005] For example, in Patent Document 1, a vehicle is provided with a first backup power supply device and a second backup power supply in addition to a main power supply. If the main power supply fails, power is supplied from the first backup power supply to a first actuator in an upstream brake mechanism. Furthermore, in this case, if the first backup power supply is not sufficiently charged, power is supplied to the first actuator from the second backup power supply.

[0006] As in Patent Document 1, in conventional brake systems, the backup power supply is connected exclusively to the upstream brake mechanism to ensure power to the upstream brake mechanism. On the other hand, the backup power supply is not connected to the downstream brake mechanism. For example, in the event of a main power failure, the valve of the downstream brake mechanism is opened and hydraulic pressure based on brake pedal operation is applied directly as braking pressure to the wheels. By limiting the power supply destination of the backup power supply to the upstream brake mechanism, power to the upstream brake mechanism is ensured. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-90246 Summary of the Invention [Problem to be solved by the invention]

[0008] The upstream brake mechanism and the downstream brake mechanism each have an actuator that generates hydraulic pressure. When inspecting the operation of these actuators, power is supplied to each actuator. As described above, in conventional brake systems, power from a backup power supply is supplied exclusively to the upstream brake mechanism. This makes it difficult to inspect the operation of the downstream brake mechanism using the backup power supply.

[0009] This specification discloses a vehicle brake system that uses a backup power supply to enable operational inspection of an upstream brake mechanism and a downstream brake mechanism, and that also ensures power supplied from the backup power supply to the upstream brake mechanism when the main power supply fails while the vehicle is running. [Means for solving the problem]

[0010] This specification discloses a vehicle brake device. The device includes an upstream brake mechanism, a downstream brake mechanism, an upstream power line, a downstream power line, and a power supply controller. The upstream brake mechanism generates hydraulic pressure based on the amount of brake pedal operation. The downstream brake mechanism distributes the hydraulic pressure generated by the upstream brake mechanism to brake pressures for each wheel. The upstream power line connects a backup power source to the upstream brake mechanism. The downstream power line includes a backup power cable and a backup switch. The backup power cable connects the backup power source to the downstream brake mechanism. The backup switch is provided on the backup power cable. The power supply controller includes a switch operation unit. The switch operation unit is capable of operating the backup switch. The switch operation unit performs a switching determination. The switching determination determines whether to switch the backup switch from an off state to an on state. This switching determination is performed when the vehicle is stopped and the cruise control system is turned off.

[0011] According to the above configuration, power can be supplied from the backup power supply to the downstream brake mechanism via the downstream power line. Furthermore, the switching determination is performed after the vehicle has stopped traveling. In other words, the power supply from the backup power supply to the downstream brake mechanism is suppressed while the vehicle is traveling. This ensures that power can be supplied from the backup power supply to the upstream brake mechanism while the vehicle is traveling.

[0012] In the above configuration, the power supply controller may include a management unit that calculates the SOC of the backup power supply. In this case, the switch operation unit determines whether the backup power supply is fully charged as a switching determination.

[0013] According to the above configuration, it is possible to prevent the backup power supply from running out of power during an operation inspection of the upstream brake mechanism and the downstream brake mechanism.

[0014] Furthermore, in the above configuration, the vehicle brake device may include a main power line and a downstream brake controller. The main power line includes a main power cable and a main switch. The main power cable connects the main power source and the downstream brake mechanism. The main switch is provided on the main power cable. The downstream brake controller is capable of operating the main switch. There are cases where the voltage of the main power source exceeds the voltage of the backup power source. In this case, when the backup switch is switched from an off state to an on state, the downstream brake controller switches the main switch from an on state to an off state.

[0015] According to the above configuration, when the backup power supply is connected to the downstream brake, it is possible to prevent power from being supplied from the main power supply instead of from the backup power supply.

[0016] In the above configuration, the backup power supply may be a capacitor cell. In this case, when the vehicle is stopped and the cruise control system is turned off, the power supply controller discharges the capacitor cell until the charge level becomes zero.

[0017] According to the above configuration, the power of the capacitor cell, which has conventionally been wasted, can be used to check the operation of the upstream brake mechanism and the downstream brake mechanism. [Effects of the Invention]

[0018] The vehicle brake device disclosed in this specification enables the operation of the upstream brake mechanism and the downstream brake mechanism to be inspected using a backup power supply, and also ensures the supply of power from the backup power supply to the upstream brake mechanism when the main power supply fails while the vehicle is running. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a brake system diagram illustrating a vehicle brake device according to an embodiment of the present invention; [Figure 2]1 is a diagram illustrating an example of an outline of power supply and signal transmission / reception of a vehicle brake device according to an embodiment of the present invention. [Figure 3] 10 is a flowchart illustrating a self-check process. DETAILED DESCRIPTION OF THE INVENTION

[0020] The vehicle brake device according to this embodiment will be described below with reference to the drawings. The shapes, materials, numbers, and values ​​described below are examples for the purpose of explanation and can be changed as appropriate depending on the specifications of the vehicle brake device. Furthermore, the same reference numerals will be used to designate equivalent elements in all drawings.

[0021] <Overall structure> Fig. 1 illustrates a brake system diagram of a vehicle brake device according to this embodiment, and Fig. 2 illustrates an outline of power supply and signal transmission / reception of the vehicle brake device according to this embodiment.

[0022] A vehicle brake system can apply brake pressure to the four wheels of a vehicle (front right wheel, front left wheel, rear right wheel, and rear left wheel). The vehicle brake system is hydraulic, and pressure is transmitted via brake fluid.

[0023] The vehicle brake system is a so-called brake-by-wire type brake system, which is divided into three systems: an upstream brake system, a downstream brake system, and a power supply system.

[0024] The upstream brake system includes an upstream brake mechanism 10 and an upstream brake controller 100. In the upstream brake system, hydraulic pressure corresponding to the amount of operation of a brake pedal 14 is generated by driving a motor M1.

[0025] The downstream brake system includes a downstream brake mechanism 50 and a downstream brake controller 110. In the downstream brake system, the hydraulic pressure generated in the upstream brake system is distributed to brake parts Bfr, ​​Bfl, Brr, and Brl provided on each of the four wheels of the vehicle.

[0026] The upstream brake system and the downstream brake system each include a plurality of actuators, such as solenoid valves, motors, and cut valves, which will be described in detail later.

[0027] These actuators are supplied with power from a power supply system. As illustrated in Fig. 2, the power supply system includes a main power supply 60, a backup power supply 70, and a power supply controller 80. As will be described later, when the driving control system is turned off after vehicle operation has ended, a self-check is performed on the upstream brake system and the downstream brake system. The self-check is an operation check of the actuators of the upstream brake system and the downstream brake system.

[0028] This self-check uses power from the main power supply 60 or the backup power supply 70. In particular, when the backup power supply 70 is fully charged, the power required for the self-check is supplied exclusively from the backup power supply 70.

[0029] <Upstream brake system> Referring to FIG. 1, the upstream brake system includes an upstream brake mechanism 10 and an upstream brake controller 100.

[0030] The upstream brake mechanism 10 generates hydraulic pressure in accordance with the amount of operation of the brake pedal 14. The upstream brake mechanism 10 includes a reservoir 12, a brake pedal 14, a master cylinder 20, a stroke simulator SS, and multiple actuators. As actuators, the upstream brake mechanism 10 includes a motor M1, a pump P1, solenoid valves SLM1 and SLM2, and cut valves SGH and SSA. The upstream brake mechanism 10 also includes hydraulic sensors Sgap and Ssrv.

[0031] The reservoir 12 stores brake fluid, which is a pressure transmission medium. The master cylinder 20 generates hydraulic pressure mainly for the front wheels in accordance with the amount of operation of the brake pedal 14. The master cylinder 20 includes an operating rod 18, an input piston 21, a pressure piston 22, and a cylinder piston 23. The master cylinder 20 also includes a separation chamber 24 and a servo chamber 25 inside. The separation chamber 24 is connected to a stroke simulator SS via a cut valve SGH. The pressure piston 22 is provided on the upstream side of the servo chamber 25, and the cylinder piston 23 is provided on the downstream side.

[0032] 1 is known, and will be briefly described below. When the brake pedal 14 is depressed, the operating rod 18 moves toward the master cylinder 20. The input piston 21 is pushed by the operating rod 18 and enters the separation chamber 24.

[0033] The hydraulic pressure in the separation chamber 24 is transmitted to the stroke simulator SS via the cut valve SGH. The stroke simulator SS houses a piston and a spring inside. The piston of the stroke simulator SS is pushed in response to the depression of the brake pedal 14. This generates a reaction force in the spring. This reaction force creates the brake pedal feel.

[0034] The amount of operation of the brake pedal 14 is detected by a stroke sensor 16. The amount of operation detected by the stroke sensor 16 is transmitted to an equipment control unit 100G (see FIG. 2) of the upstream brake controller 100. The equipment control unit 100G generates a drive command (e.g., a PWM signal) according to the amount of operation of the brake pedal 14. In response to the drive command, the inverter INV1 operates, and power is supplied to the motor M1.

[0035] As shown in Fig. 1, when the motor M1 is driven, hydraulic pressure is applied to the rear wheel brake mechanism 50B. Hydraulic pressure is also applied to the servo chamber 25 of the master cylinder 20 via the solenoid valve SLM2. This pushes the cylinder piston 23. As the cylinder piston 23 moves, hydraulic pressure is also applied to the front wheel brake mechanism 50A.

[0036] The solenoid valves SLM1 and SLM2 of the upstream brake mechanism 10 are configured, for example, by linear solenoids. The opening of the linear solenoid valves is adjusted according to the supplied current. As illustrated in FIG. 2, the device control unit 100G of the upstream brake controller 100 transmits command current values ​​to the PWM controllers PWM1 and PWM2. The PWM controllers PWM1 and PWM2 supply currents according to the command current values ​​to the solenoid valves SLM1 and SLM2.

[0037] The cut valve SGH is a so-called normally closed valve, which is closed when no current is supplied. The cut valve SSA is a so-called normally open valve, which is open when no current is supplied.

[0038] For example, in the event of a power failure, the normally closed cut valve SGH is closed. In other words, the hydraulic pressure transmission path from the brake pedal 14 to the stroke simulator SS is blocked by the cut valve SGH. When the brake pedal 14 is depressed in this state, the pressurizing piston 22 is pushed. Further, the advancement of the pressurizing piston 22 pressurizes the servo chamber 25, which in turn pressurizes the cylinder piston 23. This applies hydraulic pressure to the front wheel brake mechanism 50A.

[0039] The upstream brake mechanism 10 is provided with hydraulic pressure sensors Sgap and Ssrv. The hydraulic pressure sensor Sgap is provided between the separation chamber 24 and the cut valve SGH. The hydraulic pressure sensor Ssrv is provided between the pump P1 and the solenoid valves SLM2 and SM2. The hydraulic pressure values ​​detected by the hydraulic pressure sensors Sgap and Ssrv are sent to a device control unit 100G and an abnormality determination unit 100H of the upstream brake controller 100 (see FIG. 2).

[0040] <Upstream brake controller> As illustrated in Fig. 1, the upstream brake controller 100 is configured, for example, by a computer. The upstream brake controller 100 includes a CPU 100A as an arithmetic unit and a control unit. The upstream brake controller 100 also includes a RAM 100B, a ROM 100C, and a storage 100D as memory units. The upstream brake controller 100 also includes an input / output controller 100E as an interface unit with peripheral devices. These units are connected by an internal bus 100F.

[0041] For example, when the CPU 100A executes a brake control program stored in the storage 100D, functional modules such as those illustrated in Fig. 2 are constructed in the upstream brake controller 100. That is, the upstream brake controller 100 includes an equipment control unit 100G, an abnormality determination unit 100H, and a switch operation unit 100I.

[0042] The device control unit 100G controls various actuators of the upstream brake mechanism 10. For example, the device control unit 100G controls the driving of the solenoid valves SLM1 and SLM2, the cut valves SSA and SGH, and the motor M1.

[0043] The abnormality determination unit 100H determines whether or not there is an abnormality in the actuator based on the hydraulic pressure values ​​detected by the hydraulic pressure sensors Ssrv and Sgap during a self-check, which will be described later in detail.

[0044] The switch operation unit 100I is capable of turning on and off the main switches SW1 and SW3 of the upstream main power lines UML1 and UML2. In the self-check described below, the on and off status of the main switches SW1 and SW3 is determined based on the voltages Vaux and Vbkup of the main power supply 60 and the backup power supply 70, respectively. This will be described in detail later.

[0045] <Downstream braking system> Referring to FIG. 1, the downstream braking system includes a downstream braking mechanism 50 and a downstream brake controller 110 .

[0046] The downstream brake mechanism 50 distributes the hydraulic pressure generated by the upstream brake mechanism 10 to brake pressures for each wheel. The downstream brake mechanism 50 is divided into a front wheel brake mechanism 50A and a rear wheel brake mechanism 50B. The front wheel brake mechanism 50A includes a reservoir RS1, brake parts Bfr, ​​Bfl, and multiple actuators. As actuators, the front wheel brake mechanism 50A includes a motor M2, a pump P2, a solenoid valve SM1, holding solenoid valves SFRH, SFLH, and pressure-reducing solenoid valves SFRR, SFLR. The front wheel brake mechanism 50A also includes hydraulic pressure sensors Smc, Sfr, and Sfl.

[0047] The rear wheel brake mechanism 50B includes a reservoir RS2, brake parts Brr and Brl, and multiple actuators. The actuators of the rear wheel brake mechanism 50B include a motor M3, a pump P3, a solenoid valve SM2, pressure holding solenoid valves SRRH and SRLH, and pressure reducing solenoid valves SRRR and SRLR. The rear wheel brake mechanism 50B also includes hydraulic pressure sensors Srr and Srl.

[0048] The solenoid valves SM1 and SM2 are provided at the most upstream of the downstream brake mechanism 50. The solenoid valves SM1 and SM2 are configured by, for example, linear solenoids.

[0049] The holding solenoid valves SFRH, SFLH, SRRH, and SRLH are, for example, so-called on / off type solenoids that can be in two states: closed and open.The holding solenoid valves SFRH, SFLH, SRRH, and SRLH are normally open solenoids that are in the open state when demagnetized and no current is supplied.

[0050] Regarding the symbol for the holding solenoid valve, the first letter, S, indicates a solenoid valve. The second letter, F / R, indicates front / rear. The third letter, R / L, indicates right / left. Furthermore, the last letter, H, indicates that it is a holding type solenoid valve. For example, the holding solenoid valve SFRH is a solenoid valve (S) that is located on the front right wheel (FR) and is a holding type (H).

[0051] The pressure-reducing solenoid valves SFRR, SFLR, SRRR, and SRLR are, for example, on / off type solenoids. The pressure-reducing solenoid valves SFRR, SFLR, SRRR, and SRLR are normally closed solenoids that are closed when de-energized.

[0052] The first three letters of the symbol for a pressure reducing solenoid valve are defined in the same way as for a holding solenoid valve. The "R" at the end indicates that it is a pressure reducing solenoid valve.

[0053] Hydraulic pressure is applied to the brake parts Bfr, ​​Bfl, Brr, and Brl via holding solenoid valves SFRH, SFLH, SRRH, and SRLH. The brake parts Bfr, ​​Bfl, Brr, and Brl are, for example, disc brakes.

[0054] When current is supplied to the holding solenoid valves SFRH, SFLH, SRRH, and SRLH, the holding solenoid valves SFRH, SFLH, SRRH, and SRLH are closed, thereby maintaining the hydraulic pressure applied to the brake parts Bfr, ​​Bfl, Brr, and Brl.

[0055] When current is supplied to the pressure-reducing solenoid valves SFRR, SFLR, SRRR, and SRLR, the valves are opened. This reduces the hydraulic pressure applied to the brake parts Bfr, ​​Bfl, Brr, and Brl. The brake fluid sent from the pressure-reducing solenoid valves SFRR, SFLR, SRRR, and SRLR is temporarily stored in reservoirs RS1 and RS2. Furthermore, pumps P2 and P3 return the brake fluid from reservoirs RS1 and RS2 to the upstream brake mechanism 10.

[0056] The downstream brake mechanism 50 is provided with hydraulic pressure sensors Smc, Sfr, Sfl, Srr, and Srl. The hydraulic pressure sensor Smc is provided upstream of the solenoid valve SM1. The hydraulic pressure sensor Smc detects the hydraulic pressure at the most upstream point of the front wheel brake mechanism 50A. The hydraulic pressure sensors Sfr, Sfl, Srr, and Srl detect the hydraulic pressure applied to the brake parts Bfr, ​​Bfl, Brr, and Brl, respectively. The hydraulic pressure values ​​detected by these hydraulic pressure sensors Smc, Sfr, Sfl, Srr, and Srl are sent to the downstream brake controller 110 (see FIG. 2). More specifically, the hydraulic pressure values ​​are sent to the equipment control unit 110G and the abnormality determination unit 110H.

[0057] <Downstream brake controller> 1, the downstream brake controller 110 is configured by, for example, a computer. Similar to the upstream brake controller 100, the downstream brake controller 110 includes a CPU 110A, a RAM 110B, a ROM 110C, a storage 110D, and an input / output controller 110E. These devices are connected by an internal bus 110F.

[0058] For example, when the CPU 110A executes a brake control program stored in the storage 110D, functional modules such as those illustrated in Fig. 2 are constructed in the downstream brake controller 110. That is, the downstream brake controller 110 includes an equipment control unit 110G, an abnormality determination unit 110H, and a switch operation unit 110I.

[0059] The device control unit 110G controls various actuators of the downstream brake mechanism 50. For example, the device control unit 110G controls the driving of the linear solenoid valves SM1 and SM2, the holding solenoid valves SFRH, SFLH, SRRH, and SRLH, the pressure-reducing solenoid valves SFRR, SFLR, SRRR, and SRLR, and the motors M2 and M3.

[0060] The abnormality determination unit 110H determines whether or not there is an abnormality in the above actuators based on the hydraulic pressure values ​​detected by the hydraulic pressure sensors Smc, Sfr, Sfl, Srr, and Srl during a self-check, which will be described later in detail.

[0061] The switch operation unit 110I is capable of turning on and off the main switches SW5 and SW7 of the downstream main power lines LML1 and LML2. In the self-check described below, the on and off status of the main switches SW5 and SW7 is determined based on the voltages Vaux and Vbkup of the main power supply 60 and the backup power supply 70. This will be described in detail later.

[0062] <Power configuration> 2, the vehicle brake device according to this embodiment includes a main power supply 60 and a backup power supply 70. The main power supply 60 is, for example, an auxiliary battery mounted on the vehicle. A DC / DC converter may be provided between the main power supply 60 and the upstream brake mechanism 10 and the downstream brake mechanism 50.

[0063] The backup power supply 70 is composed of, for example, a capacitor cell. The backup power supply 70 is charged to a full charge when the vehicle is started. When the vehicle stops running and the driving control system is turned off, the backup power supply 70 is discharged until the charge level becomes zero.

[0064] For example, the backup power supply 70 can be connected to a resistor (not shown) via a switch or the like. In conventional brake systems, this resistor is used to discharge the backup power supply 70. The backup power supply 70 is discharged until the charge level reaches zero. In this way, the power of the backup power supply 70 would conventionally be wasted, so to speak, after the vehicle has finished traveling. As will be described later, in the vehicle brake system according to this embodiment, this power that would conventionally be wasted is used for self-checks of the upstream brake mechanism 10 and the downstream brake mechanism 50.

[0065] The power supply controller 80 manages and controls the main power supply 60 and the backup power supply 70. The power supply controller 80 is configured by, for example, a computer, and like the upstream brake controller 100 and the downstream brake controller 110, the power supply controller 80 includes devices such as a CPU, RAM, ROM, storage, and an input / output controller (not shown).

[0066] 2 is configured in the power supply controller 80 by the CPU executing a power supply control program stored in the storage of the power supply controller 80. That is, the power supply controller 80 includes a main power supply management unit 80A, a backup power supply management unit 80B, and a switch operation unit 80C.

[0067] The main power supply management unit 80A receives the current value and voltage value of the main power supply 60 from the current sensor 62 and the voltage sensor 64. From these detected values, the main power supply management unit 80A calculates, for example, the SOC (State Of Charge) of the main power supply 60.

[0068] The backup power supply management unit 80B receives the current value and voltage value of the backup power supply 70 from the current sensor 72 and voltage sensor 74. The backup power supply management unit 80B calculates the SOC of the backup power supply 70 from these detected values.

[0069] The switch operation unit 80C is capable of turning on and off the backup switches SW2 and SW4 of the upstream backup power lines UBL1 and UBL2. The switch operation unit 80C is also capable of turning on and off the backup switches SW6 and SW8 of the downstream backup power lines LBL1 and LBL2. The switch operation unit 80C is also capable of making a switching decision to switch the backup switches SW2, SW4, SW6, and SW8 from the off state to the on state.

[0070] The switching determination is made when the vehicle has finished traveling. The end of vehicle traveling means that the vehicle has stopped and the cruise control system (not shown) has been turned off. For example, the end of traveling occurs when the vehicle's shift position is selected to the P position and the electrical connection between the large-capacity battery and the rotating electrical machine, which is the drive source, is cut off. This end of traveling is also referred to as IG-OFF in FIG. 3.

[0071] When the electrical connection between the large-capacity battery and the drive source is interrupted, the driving control system transmits a driving end notification to the power supply controller 80. This driving end notification triggers the execution of a self-check flow (see FIG. 3). The self-check flow will be described in detail later.

[0072] <Circuit configuration> 2, the main power supply 60 and backup power supply 70 are electrically connected to the upstream brake system and downstream brake system. As means for this connection, the vehicle brake device includes upstream main power lines UML1 and UML2 and upstream backup power lines UBL1 and UBL2. The vehicle brake device also includes downstream main power lines LML1 and LML2 and downstream backup power lines LBL1 and LBL2.

[0073] The upstream main power line UML1 includes a main power cable 91 and a main switch SW1. The main power cable 91 connects the main power supply 60 with the actuators of the upstream brake mechanism 10 and the upstream brake controller 100. The actuators to be connected include solenoid valves SLM1 and SLM2 and cut valves SSA and SGH. The main switch SW1 is provided on the main power cable 91.

[0074] The upstream main power line UML2 includes a main power cable 93 and a main switch SW3. The main power cable 93 connects the main power supply 60 and the inverter INV1. The main switch SW3 is provided on the main power cable 93.

[0075] The main switches SW1 and SW3 are turned on / off by a switch operating unit 100I of the upstream brake controller 100.

[0076] The upstream backup power line UBL1 is a power line that replaces the upstream main power line UML1. The upstream backup power line UBL1 includes a backup power cable 92 and a backup switch SW2. The backup power cable 92 connects the backup power supply 70 with the actuator of the upstream brake mechanism 10 and the upstream brake controller 100. The actuators to be connected include solenoid valves SLM1 and SLM2 and cut valves SSA and SGH. The backup switch SW2 is provided on the backup power cable 92.

[0077] The upstream backup power line UBL2 is a power line that replaces the upstream main power line UML2. The upstream backup power line UBL2 includes a backup power cable 94 and a backup switch SW4. The backup power cable 94 connects the backup power supply 70 and the inverter INV1. The backup switch SW4 is provided on the backup power cable 94.

[0078] The backup switches SW2 and SW4 are turned on / off by a switch operation unit 80C of the power supply controller 80.

[0079] In this way, the upstream brake mechanism 10 and the upstream brake controller 100 are connected to both the main power supply 60 and the backup power supply 70. As will be described later, the power supplies that supply power to the upstream brake mechanism 10 and the upstream brake controller 100 are selected by turning on / off the main switches SW1, SW3 and the backup switches SW2, SW4.

[0080] The downstream main power line LML1 includes a main power cable 95 and a main switch SW5. The main power cable 95 connects the main power supply 60 with the actuators of the downstream brake mechanism 50 and the downstream brake controller 110. The actuators to be connected include solenoid valves SM1, SM2, SFRH, SFRR, SFLH, SFLR, SRRH, SRRR, SRLH, and SRLR. The main switch SW5 is provided on the main power cable 95.

[0081] The downstream main power line LML2 includes a main power cable 97 and a main switch SW7. The main power cable 97 connects the main power supply 60 to the inverters INV2 and INV3. The main switch SW7 is provided on the main power cable 97.

[0082] The main switches SW5 and SW7 are turned on / off by a switch operating unit 110I of the downstream brake controller 110.

[0083] The downstream backup power line LBL1 is a power line that replaces the downstream main power line LML1. The downstream backup power line LBL1 includes a backup power cable 96 and a backup switch SW6. The backup power cable 96 connects the backup power supply 70 with the actuators of the downstream brake mechanism 50 and the downstream brake controller 110. The actuators to be connected include solenoid valves SM1, SM2, SFRH, SFRR, SFLH, SFLR, SRRH, SRRR, SRLH, and SRLR. The backup switch SW6 is provided on the backup power cable 96.

[0084] The downstream backup power line LBL2 is a power line that replaces the downstream main power line LML2. The downstream backup power line LBL2 includes a backup power cable 98 and a backup switch SW8. The backup power cable 98 connects the backup power supply 70 to the inverters INV2 and INV3. The backup switch SW8 is provided on the backup power cable 98.

[0085] The backup switches SW6 and SW8 are turned on / off by a switch operation unit 80C of the power supply controller 80.

[0086] In this way, the downstream brake mechanism 50 and the downstream brake controller 110 are connected to both the main power supply 60 and the backup power supply 70. As will be described later, the power supplies that supply power to the downstream brake mechanism 50 and the downstream brake controller 110 are selected by turning on / off the main switches SW5 and SW7 and the backup switches SW6 and SW8.

[0087] <Backup power connection while driving> Except when the main power supply 60 fails or during a self-check, which will be described later, the main switches SW1, SW3, SW5, and SW7 are maintained in the on state. In contrast, the backup switches SW2, SW4, SW6, and SW8 are maintained in the off state.

[0088] If the main power supply 60 fails while the vehicle is running, the switch operation unit 80C of the power supply controller 80 switches the power supply source to the backup power supply 70. Before making this switch, the switch operation unit 80C checks whether a driving control system (not shown) is on.

[0089] When the cruise control system is in the ON state, the switch operation unit 80C switches the backup switches SW2 and SW4 from the OFF state to the ON state among the backup switches SW2, SW4, SW6, and SW8, thereby supplying power from the backup power supply 70 to the upstream brake mechanism 10 and the upstream brake controller 100.

[0090] Meanwhile, the backup switches SW6 and SW8 are maintained in the OFF state, which prevents the backup power supply 70 from supplying power to the downstream brake mechanism 50 and the downstream brake controller 110. As a result, the upstream brake mechanism 10 and the upstream brake controller 100 are secured.

[0091] 1, in a cutoff state where no power is supplied to the downstream brake mechanism 50, the normally open solenoid valves SM1 and SM2 and the holding solenoid valves SFRH, SFLH, SRRH, and SRLH are open. Also, in the cutoff state, the normally closed pressure reducing solenoid valves SFRR, SFLR, SRRR, and SRLR are closed. Therefore, the hydraulic pressure of the upstream brake mechanism 10 is applied to the brake parts Bfr, ​​Bfl, Brr, and Brl via the solenoid valves SM1 and SM2 and the holding solenoid valves SFRH, SFLH, SRRH, and SRLH.

[0092] <Self-check> The vehicle brake device according to this embodiment is capable of performing a self-check on the upstream brake mechanism 10 and the downstream brake mechanism 50. In the self-check, the operation of each actuator of the upstream brake mechanism 10 and the downstream brake mechanism 50 is confirmed.

[0093] Because the upstream brake mechanism 10 and the downstream brake mechanism 50 have many actuators, some of the self-checks are illustrated below. With reference to FIGS. 1 and 2, for example, for the upstream brake mechanism 10, the equipment control unit 100G of the upstream brake controller 100 sends a drive command to the inverter INV1. After sending the command, the abnormality determination unit 100H measures the hydraulic pressure value detected by the hydraulic pressure sensor Ssrv. If the hydraulic pressure value of the hydraulic pressure sensor Ssrv does not increase within a predetermined time, the abnormality determination unit 100H determines that the pump P1 is malfunctioning.

[0094] Furthermore, with regard to the downstream brake mechanism 50, when the pump P1 is driven, the device control section 110G of the downstream brake controller 110 supplies current to (closes) the holding solenoid valves SFRH, SFLH, SRRH, and SRLH. Thereafter, the device control section 100G of the upstream brake controller 100 increases the rotation speed of the pump P1.

[0095] At this time, the abnormality determination unit 110H measures the oil pressure values ​​detected by the oil pressure sensors Sfr, Sfl, Srr, and Srl, and if the oil pressure value increases at any of the oil pressure sensors Sfr, Sfl, Srr, and Srl (for example, the oil pressure sensor Sfr), it determines that the holding solenoid valve SFRH located upstream of the oil pressure sensor Sfr is malfunctioning (not completely closed).

[0096] <Self-check flow> FIG. 3 illustrates a flowchart of a self-check according to this embodiment. This flow is executed when the vehicle has finished traveling. As described above, when the vehicle stops and the cruise control system (not shown) is turned off (IG-OFF), a cruise end notification is sent from the cruise control system to the power supply controller 80. This cruise end notification triggers the execution of the self-check flow illustrated in FIG. 3.

[0097] In the first half of the self-check flow, a switching determination is made for the backup switches SW2, SW4, SW6, and SW8 (S10). In the switching determination, it is determined whether or not the backup switches SW2, SW4, SW6, and SW8 should be switched from the OFF state to the ON state.

[0098] First, the switch operation unit 80C determines whether the backup power supply 70 is fully charged or not as a switching determination. The switch operation unit 80C acquires SOCbkup, which is the charging rate of the backup power supply 70, from the backup power supply management unit 80B. The switch operation unit 80C then determines whether the charging rate SOCbkup is equal to or greater than the full charging rate SOCmax (S10).

[0099] If the charging rate SOCbkup of the backup power supply 70 is less than the full charging rate SOCmax, the device control units 100G, 110G execute a self-check without switching the power supply (S28). At this time, power is supplied from the main power supply 60 to the upstream brake mechanism 10, the upstream brake controller 100, the downstream brake mechanism 50, and the downstream brake controller 110.

[0100] In step S10, if the charging rate SOCbkup of the backup power supply 70 is equal to or greater than the full charging rate SOCmax, the switch operation unit 80C switches the backup switches SW2 and SW6 from the OFF state to the ON state (S12). With this switching, the actuators of the upstream brake mechanism 10 and the downstream brake mechanism 50 are connected to the backup power supply 70, except for the motors M1, M2, and M3. The upstream brake controller 100 and the downstream brake controller 110 are also connected to the backup power supply 70.

[0101] Furthermore, the switch operation unit 80C switches the backup switches SW4 and SW8 from the OFF state to the ON state (S14). This switching connects the motors M1, M2, and M3 to the backup power supply 70 via the inverters INV1, INV2, and INV3.

[0102] Next, the switch operation units 100I, 110I of the upstream brake controller 100 and the downstream brake controller 110 acquire the voltage values ​​Vaux, Vbkup of the main power supply 60 and the backup power supply 70 from the voltage sensors 64, 74. Furthermore, the switch operation units 100I, 110I determine whether the voltage value Vaux of the main power supply 60 exceeds the voltage value Vbkup of the backup power supply 70 (S16).

[0103] In step S16, if Vaux≦Vbkup, the main switches SW1, SW3, SW5, and SW7 are maintained in the on state because there is no power supply from the main power supply 60. After that, the device control units 100G, 110G and abnormality determination units 100H, 110H of the upstream brake controller 100 and the downstream brake controller 110 perform the self-check described above (S22).

[0104] On the other hand, if Vaux>Vbkup, the upstream brake mechanism 10, the upstream brake controller 100, the downstream brake mechanism 50, and the downstream brake controller 110 are supplied with power from the main power supply 60, not from the backup power supply 70. Therefore, the switch operation units 100I and 110I of the upstream brake controller 100 and the downstream brake controller 110 switch the main switches SW1, SW3, SW5, and SW7 from the on state to the off state (S18).

[0105] In this way, the power supply source to the upstream brake mechanism 10, the upstream brake controller 100, the downstream brake mechanism 50, and the downstream brake controller 110 is switched from the main power supply 60 to the backup power supply 70. After that, the device control units 100G, 110G and the abnormality determination units 100H, 110H of the upstream brake controller 100 and the downstream brake controller 110 perform the self-check described above (S20).

[0106] When the self-check is completed in step S20, the switch operation units 100I, 110I of the upstream brake controller 100 and the downstream brake controller 110 switch the main switches SW1, SW3, SW5, SW7 from the OFF state to the ON state (S24).

[0107] Furthermore, the switch operation unit 80C of the power supply controller 80 switches the backup switches SW2, SW4, SW6, and SW8 from the on state to the off state (S26).

[0108] 3 is completed, the backup power supply management unit 80B of the power supply controller 80 determines whether the backup power supply 70 has been completely discharged. That is, the backup power supply management unit 80B calculates the SOC of the backup power supply 70. If the SOC of the backup power supply 70 is higher than 0%, the switch operation unit 80C connects the backup power supply 70 to a resistor (not shown). This causes the backup power supply 70 to discharge until its charge level reaches zero.

[0109] As described above, in the vehicle brake device according to this embodiment, by providing the downstream backup power lines LBL1, LBL2, it becomes possible to supply power from the backup power source 70 to the downstream brake mechanism 50 and the downstream brake controller 110 as well.

[0110] Furthermore, the period during which power is supplied from the backup power supply 70 to the downstream brake mechanism 50 and the downstream brake controller 110 is determined after the vehicle has stopped traveling. Therefore, while the vehicle is traveling, power is prevented from flowing from the backup power supply 70 to the downstream brake mechanism 50 and the downstream brake controller 110. As a result, backup power is ensured for the upstream brake mechanism 10 and the upstream brake controller 100 while the vehicle is traveling.

[0111] Note that the upstream brake mechanism 10 and the downstream brake mechanism 50 have a wide variety of actuators, and it may be difficult to complete the self-check with the capacity of the backup power supply 70. Therefore, certain actuators may be excluded from the self-check.

[0112] For example, the motors M2 and M3 of the downstream brake mechanism 50 are excluded from the self-check. For example, in step S14 of FIG. 3, the on / off switching of the backup switch SW8 is omitted. In other words, the backup switch SW8 is maintained in the off state. As a result, the motors M2 and M3 do not receive power supply from the backup power supply 70. In other words, the motors M2 and M3, which consume a relatively large amount of power among the actuators, are excluded from the power supply destinations of the backup power supply 70. This makes it possible to more reliably perform the self-check using the backup power supply 70 as the power supply source. [Explanation of symbols]

[0113] 10 upstream brake mechanism, 14 brake pedal, 50 downstream brake mechanism, 60 main power supply, 70 backup power supply, 80 power supply controller, 80A main power supply management section, 80B backup power supply management section, 80C switch operation section of power supply controller, 91, 93, 95, 97 main power cables, 92, 94, 96, 98 backup power cables, 100 upstream brake controller, 100I switch operation section of upstream brake controller, 110 downstream brake controller, 110I switch operation section of downstream brake controller, LBL1, LBL2 downstream backup power lines, LML1, LML2 downstream main power lines, SW1, SW3, SW5, SW7 main switches, SW2, SW4, SW6, SW8 backup switches, UBL1, UBL2 upstream backup power lines, UML1, UML2 upstream main power lines.

Claims

1. an upstream brake mechanism that generates hydraulic pressure based on the amount of operation of the brake pedal; a downstream brake mechanism that distributes hydraulic pressure generated by the upstream brake mechanism to brake pressures of the respective wheels; an upstream power line connecting a backup power source to the upstream brake mechanism; a downstream power line including a backup power cable connecting the backup power source and the downstream brake mechanism, and a backup switch provided on the backup power cable; a power supply controller including a switch operation unit capable of operating the backup switch; Equipped with the switch operation unit executes a switching determination to determine whether to switch the backup switch from an off state to an on state; The switching determination is performed when the vehicle stops and the driving control system is turned off. Vehicle braking system.

2. 2. A vehicle brake device according to claim 1, the power supply controller includes a management unit that calculates an SOC of the backup power supply; The switch operation unit determines whether the backup power supply is fully charged or not as the switching determination. Vehicle braking system.

3. 3. A vehicle brake device according to claim 2, a main power line including a main power cable connecting a main power source and the downstream brake mechanism, and a main switch provided on the main power cable; a downstream brake controller operable to operate the main switch; Equipped with When the voltage of the main power supply exceeds the voltage of the backup power supply, the downstream brake controller switches the main switch from an on state to an off state when the backup switch is switched from an off state to an on state. Vehicle braking system.

4. A vehicle brake device according to any one of claims 1 to 3, the backup power source is a capacitor cell; When the vehicle stops and the driving control system is turned off, the power supply controller discharges the capacitor cell until the charge amount becomes zero. Vehicle braking system.

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