JP2022154482A - Vehicular braking apparatus - Google Patents

Abstract

To provide a vehicular braking apparatus capable of improving the foreign matter removal performance of removing foreign matter inside an electromagnetic valve.SOLUTION: A vehicular braking apparatus includes: a stroke simulator 43; a pressurizing/depressurizing device 2 connected to the stroke simulator 43 via a liquid passage 500 and capable of pressurizing/depressurizing the liquid passage 500 without depending on a driver's operation; object electromagnetic valves 44, 61, 62 that are electromagnetic valves provided in the liquid passage 500; and a control unit 91 for executing refreshing control in which the pressurizing/depressurizing device 2 is made to execute pressurizing processing for pressurizing the stroke simulator 43 and the liquid passage 500 while the object electromagnetic valves 44, 61, 62 are opened, and then to execute depressurizing processing for depressurizing the liquid passage 500, thereby causing fluid to flow from the stroke simulator 43 toward the object electromagnetic valves 44, 61, 62.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle braking system.

Conventionally, as described in German Patent Application No. 102017211874, for example, in vehicle braking systems, an air bleeding control is performed for bleeding air from the brake circuit. In this device, with the solenoid valve that connects the master cylinder and the reservoir closed, the liquid passage is pressurized by the electric cylinder, and then the solenoid valve is opened to allow the fluid in the passage to flow to the reservoir together with the air. control is performed.

DE 102017211874 A1

Although the above control is effective for removing air, it may not be possible to ensure a sufficient flow rate for removing foreign matter in the liquid passage, particularly foreign matter that has entered the electromagnetic valve. If a foreign object enters the solenoid valve, it may cause a failure that prevents the solenoid valve from closing. In the above device, there is room for improvement in terms of removing foreign matter in the solenoid valve.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle brake system capable of improving foreign matter removal performance for removing foreign matter in an electromagnetic valve.

A vehicle braking device according to the present invention includes a cylinder and a piston biased toward an initial position by a biasing member provided inside the cylinder, and fluid is supplied from a fluid passage connected to the cylinder. A stroke simulator in which the piston moves away from the initial position against the urging force of the urging member, and a subject solenoid valve, which is a solenoid valve provided in the liquid path, are sandwiched between the stroke and the stroke through the liquid path. a pressurization/decompression device connected to the simulator and configured to pressurize or depressurize the liquid passage by supplying fluid to or discharging the fluid from the liquid passage without depending on the operation of a driver; After causing the pressurization/decompression device to execute a pressurization process for pressurizing the stroke simulator and the liquid path with the valve opened, the fluid is removed from the stroke simulator by executing a depressurization process for depressurizing the liquid path. toward the target solenoid valve.

According to the present invention, the piston moves away from the initial position by pressurizing the stroke simulator while the target solenoid valve is open. After that, when the fluid path is depressurized, the fluid is pushed out from the stroke simulator into the fluid path and flows toward the target solenoid valve. The fluid in the fluid path flows away from the stroke simulator and is further subjected to force due to the return of the piston of the stroke simulator to its initial position. As a result, the flow rate (flow velocity) of the fluid flowing from the stroke simulator to the target solenoid valve increases. Therefore, the foreign matter in the target solenoid valve is easily removed from the target solenoid valve by the forceful fluid. ADVANTAGE OF THE INVENTION According to this invention, the foreign material removal performance which removes the foreign material in an electromagnetic valve can be improved.

1 is a configuration diagram of a vehicle braking device according to an embodiment; FIG. 4 is a flowchart of first refresh control according to the embodiment; 7 is a flow chart of a modification of the first refresh control of the embodiment;

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1 , the vehicle braking system 1 of this embodiment includes an upstream unit 11 , a downstream unit 3 , a first brake ECU 901 and a second brake ECU 902 . A vehicle braking device 1 is a device capable of supplying fluid to wheel cylinders 81, 82, 83, and 84 provided on wheels of a vehicle. The first brake ECU 901 controls at least the upstream unit 11 . The second brake ECU 902 controls at least the downstream unit 3 .

(upstream unit)
The upstream unit 11 includes a master cylinder device 4, a stroke simulator 43, a simulator cut valve 44, a reservoir 45, a first fluid passage 51, an electric cylinder (corresponding to a "compression device") 2, and a second A liquid passage 52 , a communication passage 53 , a liquid passage 54 , a master cut valve 62 , a system cutoff valve 61 , a stroke sensor 71 , and pressure sensors 72 and 73 are provided. FIG. 1 shows a non-energized state of the vehicle braking device 1 .

The master cylinder device 4 is a device capable of generating hydraulic pressure in accordance with driver operation. The master cylinder device 4 includes a master cylinder 41, a master piston 42, a master chamber 41a, and a biasing member 41b. The master cylinder 41 is a bottomed cylindrical member. An input port 411 and an output port 412 are formed in the master cylinder 41 .

The input port 411 is connected to the reservoir 45 via the reservoir fluid path 40a. A reservoir cut valve 40, which is a normally open solenoid valve, is arranged in the reservoir fluid path 40a. The connection between the master cylinder 41 and the reservoir 45 is cut off by closing the reservoir cut valve 40 . The output port 412 is connected to the downstream unit 3 via the first fluid path 51 . In addition, the output port 412 is connected to the stroke simulator 43 via a portion (liquid path) 40b of the first liquid path 51 and the liquid path 43a.

The master piston 42 is a piston member arranged inside the master cylinder 41 and mechanically connected to the brake pedal Z. As shown in FIG. The master piston 42 slides within the master cylinder 41 according to the operation of the brake pedal Z. As shown in FIG. A through hole 421 is formed in the master piston 42 . The master piston 42 is biased toward the initial position by a biasing member 41b, which will be described later. The initial position is the position of the master piston 42 when the volume of the master chamber 41a is maximized. When the master piston 42 is located at the initial position, the through hole 421 and the input port 411 communicate with each other.

The master chamber 41 a is formed inside the master cylinder 41 by the master cylinder 41 and the master piston 42 . In this embodiment, the number of master chambers 41a formed in the master cylinder 41 is one, but may be two (tandem type). The volume of the master chamber 41a changes as the master piston 42 moves. When the master piston 42 moves to one side in the axial direction, the volume of the master chamber 41a decreases and the hydraulic pressure in the master chamber 41a (hereinafter referred to as "master pressure") increases. The biasing member 41b is a spring member provided inside the master chamber 41a. When no force is acting on the master piston 42, the master piston 42 is in its initial position.

The stroke simulator 43 is connected to the master cylinder 41 via a fluid path 43 a , a simulator cut valve 44 provided in the fluid path 43 a , and a first fluid path 51 . The stroke simulator 43 is a device that generates a reaction force (load) against the operation of the brake pedal Z.

Specifically, the stroke simulator 43 includes a cylinder 431 and a piston 432 biased toward the initial position by a biasing member 433 provided inside the cylinder 431 . The stroke simulator 43 is configured such that the piston 432 moves away from the initial position against the biasing force of the biasing member 433 by pressurizing the fluid path 43a (fluid path 500, which will be described later) connected to the cylinder 431. ing. The biasing member 433 is, for example, a spring. A housing chamber 434 in which a biasing member 433 is arranged in the cylinder 431 is connected to the reservoir 45 by a liquid passage 43b. The stroke simulator 43 is connected to the output port 412 of the master cylinder 41 through the liquid passage 43a.

The simulator cut valve 44 is a normally closed electromagnetic valve provided in the liquid passage 43a. When the brake pedal Z is operated with the master cut valve 62 (to be described later) closed and the simulator cut valve 44 opened, the stroke simulator 43 generates a pedal reaction force.

A reservoir 45 stores fluid. The pressure inside the reservoir 45 is kept at atmospheric pressure. Inside the reservoir 45 are formed two storage chambers 451 and 452 each storing fluid.

The storage chamber 451 is connected to the master cylinder device 4 . Specifically, the storage chamber 451 is connected to the input port 411 of the master cylinder. When the master piston 42 is in the initial position, the storage chamber 451 is hydraulically connected to the master chamber 41a through the input port 411 and the through hole 421. As shown in FIG. When the master piston 42 slides by a predetermined amount, the input port 411 and the through hole 421 are hydraulically blocked. In this case, master chamber 41a and reservoir 45 are hydraulically disconnected. The storage chamber 452 is connected to the electric cylinder 2 via the liquid passage 54 . Note that the reservoir 45 may be composed of two separate reservoirs instead of two storage chambers.

The first fluid path 51 is a fluid path that connects the master cylinder device 4 and the downstream unit 3 . The first liquid path 51 is connected to the master chamber 41a through the output port 412. As shown in FIG. When the master piston 42 slides to reduce the size of the master chamber 41 a while the master chamber 41 a and the reservoir 45 are hydraulically isolated from each other, the first fluid passage 51 flows from the master chamber 41 a through the output port 412 . is supplied to the first fluid passage 51, and fluid pressure is generated in the first fluid passage 51. The hydraulic pressure generated in the master chamber 41 a is supplied to the downstream unit 3 through the first liquid passage 51 . The first liquid path 51 includes a connecting portion 50 connected to a communication path 53, which will be described later. A master cut valve 62 and a pressure sensor 72 are provided in the first liquid path 51 .

The master cut valve 62 is a normally open electromagnetic valve provided closer to the master cylinder device 4 than the connecting portion 50 in the first fluid passage 51 . When the master cut valve 62 is closed, the master cylinder device 4 and the downstream unit 3 are hydraulically cut off.

The pressure sensor 72 is provided closer to the master cylinder device 4 than the master cut valve 62 in the first fluid passage 51 . A pressure sensor 72 detects the pressure in the first liquid passage 51 . The pressure detected by the pressure sensor 72 when the master cut valve 62 is closed corresponds to the master pressure, which is the pressure generated within the master chamber.

(electric cylinder)
The electric cylinder 2 includes a cylinder 21 , an electric motor 22 , a piston 23 , a hydraulic pressure chamber 24 and an urging member 25 . The electric cylinder 2 is a single-type electric cylinder in which a single hydraulic chamber 24 is formed in the cylinder 21 as an output chamber. In the description of the electric cylinder 2 of the present disclosure, the direction in which the piston 23 makes the hydraulic pressure chamber 24 smaller is the front, and the direction in which the piston 23 makes the hydraulic pressure chamber 24 larger is the rear. This does not have to correspond to the longitudinal direction of the vehicle.

The cylinder 21 is a cylindrical portion (or member) with a bottom. An input port 211 and an output port 212 are formed in the cylinder 21 . As shown in FIG. 2, the input port 211 is an opening formed between two seal members provided on the cylinder 21 . The sealing member is an annular cup seal. The output port 212 is an opening and is formed in front of the input port 211 .

The electric motor 22 is connected to the piston 23 via a linear motion mechanism 22a that converts rotary motion into linear motion. The piston 23 is a cylindrical member with a bottom, and is driven by the electric motor 22 to slide inside the cylinder 21 . A through hole 231 is formed in the piston 23 . When the piston 23 is located at the initial position, the fluid pressure chamber 24 and the input port 211 communicate with each other through the through hole 231 .

The hydraulic chamber 24 is defined by the cylinder 21 and the piston 23, and its volume changes as the piston 23 moves. The initial position of the piston 23 is the position where the volume of the hydraulic chamber 24 is maximized. As the piston 23 moves forward, the volume of the hydraulic chamber 24 decreases.

The hydraulic chamber 24 can communicate with the reservoir 45 via the input port 211 . Specifically, when piston 23 is in its initial position, it is hydraulically connected to reservoir 45 via through hole 231 , input port 211 and fluid passage 54 . When the through hole 231 and the input port 211 are not in communication, the fluid pressure chamber 24 and the reservoir 45 are hydraulically cut off. The fluid pressure chamber 24 is connected to the second fluid path 52 via the output port 212 .

When the electric motor 22 is driven to move the piston 23 forward by a predetermined amount, communication between the input port 211 and the through hole 231 is cut off. In this case, hydraulic chamber 24 is hydraulically isolated from reservoir 45 . When the fluid pressure chamber 24 and the reservoir 45 are hydraulically isolated from each other and the piston 23 slides to make the fluid pressure chamber 24 smaller, the fluid flows from the fluid pressure chamber 24 through the output port 212 to the second pressure chamber 24 . The liquid is supplied to the liquid path 52 and hydraulic pressure is generated in the second liquid path 52 .

The biasing member 25 is a spring arranged in the hydraulic pressure chamber 24 and biasing the piston 23 toward the initial position. When the electric motor 22 is not driven, the biasing force of the biasing member 25 positions the piston 23 at the initial position.

The second fluid path 52 is a fluid path that connects the electric cylinder 2 and the downstream unit 3 . The hydraulic pressure generated in the hydraulic pressure chamber 24 is supplied to the downstream unit 3 via the second hydraulic passage 52 . A pressure sensor 73 is provided in the second liquid path. The first fluid path 51 and the second fluid path 52 are portions of the fluid paths that connect the master cylinder device 4 and the downstream unit 3 and are arranged inside the upstream unit 11 .

The pressure sensor 73 is a sensor that detects the pressure inside the second liquid path 52 . The hydraulic pressure detected by the pressure sensor 73 corresponds to the output pressure of the electric cylinder 2 when the control mode of the vehicle braking system 1 is a brake-by-wire mode (hereinafter referred to as “by-wire mode”), which will be described later.

The communication path 53 is a fluid path that connects the first fluid path 51 and the second fluid path 52 . The communication path 53 is connected to the first liquid path 51 at the connection portion 50 . A system cutoff valve 61 is provided in the communication passage 53 . By closing the system shutoff valve 61, communication between the wheel cylinders 81, 82 of the first system and the wheel cylinders 83, 84 of the second system is cut off.

The system cutoff valve 61 is a normally closed solenoid valve. The valve body of the system cutoff valve 61 is arranged closer to the first liquid passage 51 than the valve seat. Therefore, in the communication passage 53 , when the pressure on the first liquid passage 51 side is higher than the pressure on the second liquid passage 52 side, a force acts on the system cutoff valve 61 in the valve closing direction. As a result, even if the hydraulic pressure of the wheel cylinders 81 and 82 becomes higher than the output pressure of the electric cylinder 2 when the system cutoff valve 61 is closed, force is applied to the valve body in the direction of pressing it against the valve seat (self-sealing). ) and the valve remains closed. The system shutoff valve 61 can also be said to be a communication control valve that controls the connection state between the first fluid path 51 and the second fluid path 52 .

A stroke sensor 71 detects the stroke of the brake pedal Z. In this embodiment, two stroke sensors 71 are provided. Data detected by the two stroke sensors 71 are transmitted to each brake ECU 901 and 902 . Brake ECUs 901 and 902 acquire stroke information from corresponding stroke sensors 71 .

(downstream unit)
The downstream unit 3 is a so-called ESC actuator and can independently adjust the hydraulic pressure of each of the wheel cylinders 81-84. The downstream unit 3 includes a plurality of electromagnetic valves, pumps, motors, reservoirs, etc., although not shown. The downstream unit 3 includes a first hydraulic pressure output section 31 configured to be able to regulate the pressure of the wheel cylinders 81 and 82, and a second hydraulic pressure output section 32 configured to be capable of adjusting the pressure of the wheel cylinders 83 and 84. I have. The downstream unit 3 can be said to be a pressurizing device that is provided separately from the electric cylinder 2 and capable of pressurizing the wheel cylinders 81 to 84 . The detailed configuration of the downstream unit 3 is omitted because it is a known actuator.

(Brake ECU)
A first brake ECU 901 and a second brake ECU 902 (hereinafter also referred to as "brake ECUs 901 and 902") are electronic control units each having a CPU and a memory. Each brake ECU 901, 902 has one or more processors that perform various controls. The first brake ECU 901 and the second brake ECU 902 are separate ECUs, and are connected so as to be able to communicate information (control information, etc.) with each other.

The first brake ECU 901 is configured to be able to control the upstream unit 11 . Specifically, the first brake ECU 901 can control the electric cylinder 2 and the solenoid valves 61, 62, 44, 40 based on data detected by the sensors 71, 72, 73 of the upstream units. The first brake ECU 901 can calculate each wheel pressure based on the detection results of the pressure sensors 72 and 73 and the control state of the downstream unit 3 .

The second brake ECU 902 is configured to be able to control the downstream unit 3 based on data detected by the stroke sensor 71 and an internal pressure sensor (not shown). The second brake ECU 902 also receives data detected by a wheel speed sensor (not shown), an acceleration sensor (not shown), etc. provided in the vehicle. The second brake ECU 902 can control the downstream unit 3 (pressurization control, pressure reduction control, and holding control) to adjust the hydraulic pressure of each of the wheel cylinders 81-84. The second brake ECU 902 is configured to be capable of executing anti-skid control (ABS control), sideslip prevention control, and the like.

The vehicle braking system 1 is configured to be able to perform normal control. Normal control is also called by-wire mode. In normal control, the output pressure of the upstream unit 11 is the hydraulic pressure output by the electric cylinder 2 . The downstream unit 3 can output hydraulic pressure to the wheel cylinders 81-84 based on the output pressure of the upstream unit 11. FIG. The normal control will be described below.

(Normal control)
The normal control is a control in which the master cylinder device 4 and the wheel cylinders 81 to 84 are hydraulically disconnected and the wheel cylinders 81 to 84 are pressurized by at least one of the electric cylinder 2 and the downstream unit 3 . Normal control includes preparation control and normal pressurization control.

The preparation control is a control forming a so-called by-wire mode. In preparation control, the control unit 91 closes the master cut valve 62 and opens the system cutoff valve 61 and the simulator cut valve 44 . The preparation control is executed when the vehicle provided with the vehicle braking device 1 becomes ready to start. The state in which the vehicle is ready to start means, for example, when the ignition of the vehicle is turned on or when the electric vehicle is started.

The normal pressurization control is a control that pressurizes the wheel cylinders 81 to 84 in the by-wire mode (preparation control completed state). In normal pressurization control, the first brake ECU 901 sets the target output pressure based on data detected by the stroke sensor 71 and the pressure sensor 72 . The electric cylinder 2 is controlled based on the set target output pressure. The second brake ECU 902 operates the downstream unit 3 when executing antiskid control or the like. In this way, in the normal control, the electric cylinder 2, the first hydraulic pressure output section 31, and the second hydraulic pressure output section 32 are controlled based on the set target value, so that the hydraulic pressure of the wheel cylinders 81 to 84 is Pressure becomes adjustable.

(refresh control)
A liquid passage 500 connecting the electric cylinder 2 and the stroke simulator 43 connects the portion of the second liquid passage 52 that connects the electric cylinder 2 and the communication passage 53, the communication passage 53, and the first liquid passage 51. It is composed of a portion connecting the portion 50 and the liquid path 43a and the liquid path 43a (see the thick line in FIG. 1). As one of the fluid paths connected to the master cylinder 41, a fluid path 40b is a fluid path that connects a portion of the fluid path 500 between the simulator cut valve 44 and the master cut valve 62 to the master cylinder 41. be.

The electric cylinder 2 is connected to the stroke simulator 43 via the fluid path 500, and is configured to be able to pressurize and depressurize the fluid path 500 without being operated by the driver. The master cylinder 41 is connected to the reservoir 45 via the reservoir fluid path 40a and is connected to the fluid path 500 via the part 40b of the first fluid path 51 .

The first brake ECU 901 includes a control unit 91 that executes refresh control for removing foreign matter that has entered the solenoid valve at a predetermined timing (for example, during an initial check). The refresh control causes the electric cylinder 2 to perform pressurization processing to pressurize the stroke simulator 43 and the liquid passage 500 in a state where the target solenoid valve to be subjected to the refresh control is opened, and then decompresses the liquid passage 500 . This is a control that executes decompression processing and causes the fluid to flow from the stroke simulator 43 toward the simulator cut valve 44 .

(First refresh control)
As an example, a solenoid valve targeted for refresh control is a simulator cut valve that prohibits the flow of fluid to the stroke simulator 43 via the liquid passage 500 by closing the valve. First, refresh control for the simulator cut valve 44 will be described as "first refresh control".

In the first refresh control, the pressurization control and the decompression control are executed while maintaining the state where the simulator cut valve (corresponding to the "target solenoid valve") 44 is open, and the fluid in the stroke simulator 43 is reduced to the simulator. This control is to flow toward the cut valve 44 .

More specifically, as shown in FIG. 2, the control unit 91 opens the simulator cut valve 44, the master cut valve, and the system cutoff valve 61 and closes the reservoir cut valve 40 in the pressurization process. Then, the electric cylinder 2 is operated to pressurize the liquid passage 500 (S101).

Subsequently, the controller 91 opens the simulator cut valve 44 and the system cutoff valve 61 and closes the master cut valve 62 and the reservoir cut valve 40 , and causes the electric cylinder 2 to cut the master cut of the liquid passage 500 . A first depressurization process is performed to depressurize the portion closer to the electric cylinder 2 than the valve 62 (S102). After executing the first pressure reducing process, the control unit 91 executes a second pressure reducing process for opening the master cut valve 62 and the reservoir cut valve 40 (S102). Thus, the decompression process includes the first decompression process and the second decompression process.

In the pressurization process, the electric cylinder 2 is controlled such that the output pressure of the electric cylinder 2 is higher than the normal use range in normal braking (the hydraulic pressure range used except for sudden braking). In the pressurization process, the control unit 91 advances the piston 23 so that the piston 23 bottoms, for example. In this case, for example, the electric cylinder 2 may be controlled based on a preset target value as the pressure required for bottoming the piston 23 . Further, when the first depressurization process is completed, the piston 23 is returned to the initial position, and the fluid pressure chamber 24 and the reservoir 45 are communicated with each other.

A differential pressure is generated between both ports of the master cut valve 62 and between both ports of the reservoir cut valve 40 by the first pressure reduction process. That is, the fluid path on the upstream side of the master cut valve 62 has a higher pressure than the fluid path on the downstream side of the master cut valve 62, and the fluid path on the master cylinder 41 side of the reservoir cut valve 40 becomes the fluid path on the reservoir 45 side of the reservoir cut valve 40. Higher pressure than the liquid path.

When the second pressure reduction process is executed after the first pressure reduction process is completed, the fluid vigorously flows from the high pressure side liquid path to the low pressure side liquid path due to the differential pressure and the biasing force of the biasing member 433. do. Specifically, the fluid flows from the stroke simulator 43 into the electric cylinder 2 through the fluid passage 500 including the simulator cut valve 44, and flows from the stroke simulator 43 through the simulator cut valve 44, the master cylinder 41, and the reservoir cut valve 40. It flows into the reservoir 45 via. In other words, the fluid flows into the reservoir 45 through the master cylinder 41 and into the electric cylinder 2 through the fluid passage 500 by the second pressure reduction process.

(Effect of first refresh control)
According to the first refresh control, the fluid inside the stroke simulator 43 is pushed out to the fluid path 500 and flows away from the stroke simulator 43 via the simulator cut valve 44 . The fluid in the fluid passage 500 flows away from the stroke simulator 43 due to the differential pressure, and further receives the pressing force from the piston 432 . As a result, the flow rate (flow velocity) of the fluid flowing from the stroke simulator 43 to the simulator cut valve 44 increases. Therefore, the foreign matter in the simulator cut valve 44 is easily removed from the simulator cut valve 44 by the momentum of the fluid. According to this embodiment, it is possible to improve the performance of removing foreign matter in the solenoid valve.

In addition, in the pressurization process, fluid pressure higher than that in the normal operating range is generated in the fluid path 500 , so fluid with more force than usual flows from the electric cylinder 2 to the stroke simulator 43 via the simulator cut valve 44 . In the pressurization process, fluid flow occurs in the opposite direction to the fluid flow in the depressurization process, making it easier to remove foreign matter on the other side of the simulator cut valve 44 . Foreign matter on one side of the solenoid valve is easily removed by the pressurization process, and foreign matter on the other side of the solenoid valve is easily removed by the depressurization process.

Moreover, in this embodiment, the decompression process includes the first decompression process and the second decompression process. As a result, a differential pressure can be formed in the liquid path 500 with the master cut valve 62 as a boundary, and opening the master cut valve 62 can cause the fluid to flow vigorously. Further, in the present embodiment, the reservoir cut valve 40 is also opened in the second pressure reduction process, so the fluid flows toward the two outlets of the master cut valve 62 and the reservoir cut valve 40 . As a result, the fluid flow rate can be further increased.

(First modification of first refresh control)
A modified example of the first refresh control will be described using a first modified example and a second modified example. In the modified example, the decompression process is not divided into the first decompression process and the second decompression process as described above, and is completed in one process. In the first modification, as shown in FIG. 3, the control unit 91 first opens the simulator cut valve 44, the master cut valve, and the system cutoff valve 61 and opens the reservoir cut valve in the same manner as in the control example described above. 40 is closed, the electric cylinder 2 is operated (S201). As a result, the fluid path 500, the stroke simulator 43, and the master chamber 41a are pressurized.

Subsequently, in the depressurization process, the control unit 91 opens the reservoir cut valve 40 while maintaining the opened state of the simulator cut valve 44, the master cut valve, and the system cutoff valve 61 (S202). In addition, the control unit 91 moves the piston 23 of the electric cylinder 2 toward the initial position by stopping the operation of the electric cylinder 2 or rotating the electric motor 22 in the reverse direction in the depressurization process.

According to the first modified example of the first refresh control, the fluid passage 500 communicates with the reservoir 45 via the master cylinder 41 by opening the reservoir cut valve 40 in the pressure reduction process. As a result, the high-pressure fluid pushed out by the piston 432 of the stroke simulator 43 flows into the reservoir 45 via the simulator cut valve 44 and the master cylinder 41 . Fluid flows vigorously into the simulator cut valve 44 . As a result, the foreign matter inside the simulator cut valve 44 is removed.

(Second modification of first refresh control)
In the second modification, as shown in FIG. 3, the control unit 91 first opens the simulator cut valve 44, the master cut valve, and the system cutoff valve 61 and opens the reservoir cut valve in the same manner as in the control example described above. 40 is closed, the electric cylinder 2 is operated (S201). As a result, the fluid path 500, the stroke simulator 43, and the master chamber 41a are pressurized.

Subsequently, in the decompression process, the control unit 91 stops the operation of the electric cylinder 2 while maintaining the open state of the simulator cut valve 44, the master cut valve, and the system cutoff valve 61 and the closed state of the reservoir cut valve 40. Alternatively, by rotating the electric motor 22 in the reverse direction, the piston 23 of the electric cylinder 2 is moved toward the initial position.

According to the second modified example of the first refresh control, the electric cylinder 2 decompresses the liquid passage while maintaining the open/closed state of the solenoid valve in the pressurization process. Since opening and closing of the solenoid valve is not involved, power consumption can be suppressed more than in the first modification. Fluid flows through the simulator cut valve 44 by moving the electric cylinder 2 toward the initial position. As a result, the foreign matter inside the simulator cut valve 44 is removed.

(Second refresh control)
A solenoid valve targeted for the second refresh control is the master cut valve 62 that prohibits the flow of fluid between the stroke simulator 43 and the master cylinder 41 and the electric cylinder 2 by closing the valve. The simulator cut valve 44 is arranged in a portion between the target solenoid valve (master cut valve 62 ) and the stroke simulator 43 in the liquid path 500 . In the second refresh control, a pressurization process, a first depressurization process, and a second depressurization process are executed (see FIG. 2).

The pressurization process of the second refresh control is the same as the pressurization process of the first refresh control. In the first depressurization process, the simulator cut valve 44 and the master cut valve 62 are opened and the system cutoff valve 61 and the reservoir cut valve 40 are closed, and the electric cylinder 2 is operated to open the system cutoff valve 61 in the liquid passage 500 . A portion on the side of the electric cylinder 2 is decompressed. In the second pressure reduction process, the system cutoff valve 61 is opened while the simulator cut valve 44 and the master cut valve 62 are opened and the reservoir cut valve 40 is closed.

Due to the second refresh control, the high-pressure fluid pushed out by the piston 432 of the stroke simulator 43 vigorously flows through the fluid path 500 and flows into the electric cylinder 2 via the master cut valve 62 . As a result, the foreign matter removal performance inside the master cut valve 62 is improved.

(Third refresh control)
The electromagnetic valve subject to the third refresh control is arranged between the master cut valve 62 and the electric cylinder 2, and permits communication between the electric cylinder 2 and the wheel cylinders 83, 84 (corresponding to "first wheel cylinder"). It is a system cutoff valve 61 that switches between communication and cutoff between the electric cylinder 2 and the wheel cylinders 81 and 82 (corresponding to a "second wheel cylinder"). The third refresh control includes pressurization processing and depressurization processing (see FIG. 3).

In the pressurization process, the control unit 91 opens the simulator cut valve 44 , the master cut valve 62 , and the system cutoff valve 61 and closes the reservoir cut valve 40 . The fluid path 500 is pressurized. Subsequently, in the decompression process, the control unit 91 causes the electric cylinder 2 to open the liquid path 500 with the simulator cut valve 44, the master cut valve 62, and the system cutoff valve 61 opened and the reservoir cut valve 40 closed. is depressurized. In the pressure reduction process, the control unit 91 (forcibly) moves the piston 23 toward the initial position by the driving force of the electric motor 22, for example.

According to the third refresh control, due to the depressurization process after the pressurization process, the fluid that has been pressurized and pushed out by the piston 432 of the stroke simulator 43 vigorously flows through the fluid path 500 and is electrically driven through the system cutoff valve 61. It flows into cylinder 2. As a result, foreign matter removal performance in the system cutoff valve 61 is improved.

(others)
The present invention is not limited to the above embodiments. For example, if the reservoir cut valve 40 is not arranged in the reservoir fluid passage 40a, the connection to the reservoir 45 via the master cylinder 41 may be cut off by other means. Moreover, the pressurization/decompression device capable of pressurizing and depressurizing the liquid path 500 is not limited to the electric cylinder 2 , and may be the downstream unit 3 . For example, the downstream unit 3 such as an ESC actuator can pressurize or depressurize the liquid path connecting the downstream unit 3 and the stroke simulator 43, like the electric cylinder 2. In this case, the control unit 91 cooperates with the second brake ECU 902 to perform refresh control. Also, the master cut valve 62 may be composed of two solenoid valves connected in parallel. Also, the electric cylinder 2 may not include the biasing member 25 .

<Configuration Common to the Four Refresh Controls: Basic Configuration>
The vehicle braking system 1 includes a stroke simulator 43, a pressurization/decompression device (electric cylinder 2 or downstream unit 3), and target solenoid valves (simulator cut valve 44, master cut valve 62 , or a system cutoff valve 61 ) and a control unit 91 . The stroke simulator 43 includes a cylinder 431 and a piston 432 biased toward an initial position by a biasing member 433 provided inside the cylinder 431. Fluid is supplied from a fluid passage 500 connected to the cylinder 431. By doing so, the piston 432 is configured to move away from the initial position against the biasing force of the biasing member 433 . The pressurization/decompression device is connected to the stroke simulator 43 via the liquid path 500 with a subject solenoid valve, which is an electromagnetic valve provided in the liquid path 500, interposed therebetween. is discharged, the liquid passage 500 can be pressurized and depressurized regardless of the operation of the driver. The control unit 91 causes the pressurization/decompression device to perform pressurization processing for pressurizing the stroke simulator 43 and the liquid path 500 with the target electromagnetic valve opened, and then performs depressurization processing for depressurizing the liquid path 500 . , refresh control is executed to flow the fluid from the stroke simulator 43 toward the target solenoid valve. The depressurization process may be a one-stage depressurization process (a modified example of the first refresh control and the third refresh control), or may be a multi-stage depressurization process (the first and second refresh controls).

<Configuration Common to First Refresh Control and Second Refresh Control: First Configuration>
In addition to the basic configuration, the vehicular braking system 1 includes a shutoff valve, which is an electromagnetic valve disposed between the target electromagnetic valve (the simulator cut valve 44 or the master cut valve 62) and the pressurization/decompression device in the liquid passage 500. (Master cut valve 62 or system cutoff valve 61) is further provided. In the depressurization process of the basic configuration, the control unit 91 opens the target electromagnetic valve and closes the cutoff valve, and the pressure reduction device causes the part of the liquid path 500 closer to the pressure reduction device than the cutoff valve. After executing the first pressure reducing process for reducing the pressure, the second pressure reducing process for opening the cutoff valve is executed.

<Configuration of First Refresh Control>
In addition to the first configuration, the vehicle braking device 1 includes a reservoir fluid passage 40a that connects the master cylinder 41 and the reservoir 45, a reservoir cut valve 40 that is an electromagnetic valve provided in the reservoir fluid passage 40a, and a fluid passage. A liquid passage 40b connecting the part between the simulator cut valve 44 (target solenoid valve) and the master cut valve 62 (shutoff valve) in the part 500 and the master cylinder 41 is further provided.

The target electromagnetic valve is the simulator cut valve 44 that prohibits the flow of fluid to the stroke simulator 43 by closing the valve. The control unit 91 closes the reservoir cut valve 40 in the pressurization process and the first pressure reduction process of the first configuration, and opens the reservoir cut valve 40 in the second pressure reduction process of the first configuration.

<Configuration of Modified Example of First Refresh Control>
The vehicle braking system 1 further includes a reservoir fluid passage 40a and a reservoir cut valve 40 in addition to the basic configuration. The target solenoid valve is the simulator cut valve 44 . The control unit 91 closes the reservoir cut valve 40 in the pressurization process of the basic configuration, and opens the reservoir cut valve 40 in the pressure reduction process of the basic configuration. Decompression (decompression processing) of the liquid path 500 is performed by opening the reservoir cut valve 40 .

<Configuration of Second Refresh Control>
In the first configuration, the vehicle braking system 1 includes a simulator cut valve 44 which is an electromagnetic valve arranged between the master cut valve 62 (target electromagnetic valve) and the stroke simulator 43 in the fluid passage 500. . The target electromagnetic valve is the master cut valve 62 that, when closed, prohibits the flow of fluid between the stroke simulator 43 and the pressurization/decompression device (the electric cylinder 2 or the downstream unit 3).

In the pressurization process of the first configuration, the control unit 91 opens the simulator cut valve 44, the master cut valve 62, and the system shutoff valve 61 (shutoff valve), and controls the stroke simulator 43 and the liquid path by the pressurization/decompression device. 500 is pressurized. In the second pressure reduction process, the control unit 91 opens the system cutoff valve 61 while the simulator cut valve 44 and the master cut valve 62 are open.

<Third refresh control>
The target solenoid valve is the system cutoff valve 61, and the vehicle braking system 1 further includes a simulator cut valve 44 and a master cut valve 62 in addition to the basic configuration. The control unit 91 executes the pressurization process with the simulator cut valve 44, the master cut valve 62, and the system cutoff valve 61 opened, and closes the simulator cut valve 44, the master cut valve 62, and the system cutoff valve 61. With the valve opened, a depressurization process is performed to depressurize the liquid path 500 by the electric cylinder 2 (pressurizing/depressurizing device).

<Another Description of Refresh Control>
The vehicle braking system includes a shutoff valve, which is an electromagnetic valve, arranged in a portion of the liquid path 500 between the subject electromagnetic valve and the pressurization/decompression device. In the pressurization process, the control unit 91 pressurizes the stroke simulator 43 and the liquid path 500 with the pressurization device while maintaining the shut-off valve and the target solenoid valve in the open state. The liquid path 500 is depressurized by the pressurizing/depressurizing device while the shutoff valve and the target electromagnetic valve that have been opened are kept open.
The vehicle braking system also includes a reservoir cut valve 40 that is an electromagnetic valve provided in a reservoir fluid passage 40 a that connects the master cylinder 41 and the reservoir 45 . The subject electromagnetic valve is the simulator cut valve 44 that prohibits the flow of fluid to the stroke simulator 43 via the fluid path 500 by closing the valve. In the pressurization process, the control unit 91 pressurizes the stroke simulator 43 and the liquid path 500 with the pressurization/decompression device while maintaining the state where the shutoff valve and the target solenoid valve are opened and the reservoir cut valve 40 is closed. In the depressurization process, the reservoir cut valve 40 is opened while the shut-off valve and the target solenoid valve that were opened in the pressurization process are kept open, and the liquid path 500 is depressurized by the pressurization/decompression device.

REFERENCE SIGNS LIST 1 vehicle braking device 2 electric cylinder (pressure reducing device) 3 downstream unit (pressure reducing device) 40 reservoir cut valve 40 a reservoir liquid passage 40 b liquid passage 41 master cylinder 43 Stroke simulator 431 Cylinder 432 Piston 433 Biasing member 44 Simulator cut valve (target solenoid valve) 45 Reservoir 500 Liquid path 61 System shutoff valve (target solenoid valve, shutoff valve ), 62... master cut valve (target solenoid valve, cutoff valve), 81, 82... wheel cylinder (second wheel cylinder), 83, 84... wheel cylinder (first wheel cylinder), 91... control unit.

Claims (7)

A cylinder and a piston biased toward an initial position by a biasing member provided inside the cylinder, and the piston is biased by supplying fluid from a fluid passage connected to the cylinder. a stroke simulator that moves away from the initial position against the biasing force of the member;
It is connected to the stroke simulator via the liquid path with a target solenoid valve, which is an electromagnetic valve provided in the liquid path, interposed therebetween. a pressurization/decompression device configured to be able to pressurize or depressurize the liquid path without being operated by a driver;
After causing the pressurization/decompression device to execute a pressurization process for pressurizing the stroke simulator and the liquid path with the target solenoid valve open, a depressurization process for depressurizing the liquid path is performed to reduce the stroke. a control unit that executes refresh control for causing the fluid to flow from the simulator toward the target solenoid valve;
A vehicle braking device comprising: further comprising a shutoff valve, which is an electromagnetic valve arranged in a portion between the target electromagnetic valve and the pressurization/decompression device in the liquid path;
In the depressurization process, the control unit causes the pressure-reducing device to move the fluid path closer to the pressure-reducing device than the shut-off valve in a state in which the target solenoid valve is opened and the shut-off valve is closed. After executing the first pressure reduction process for reducing the pressure of the part, executing the second pressure reduction process for opening the shutoff valve,
The vehicle braking system according to claim 1. further comprising a reservoir cut valve, which is an electromagnetic valve provided in the reservoir fluid passage connecting the master cylinder and the reservoir,
The target electromagnetic valve is a simulator cut valve that prohibits the flow of fluid to the stroke simulator through the fluid path by closing the valve,
The control unit closes the reservoir cut valve in the pressurization process and the first decompression process, and opens the reservoir cut valve in the second decompression process.
The vehicle braking device according to claim 2. further comprising a shutoff valve, which is an electromagnetic valve arranged in a portion between the target electromagnetic valve and the pressurization/decompression device in the liquid path;
The control unit
In the pressurization process, the stroke simulator and the liquid path are pressurized by the pressurization/decompression device while maintaining the shutoff valve and the target solenoid valve in an open state,
In the depressurization process, the liquid path is depressurized by the pressurization/decompression device while the shutoff valve and the target solenoid valve, which were opened in the pressurization process, are kept open.
The vehicle braking system according to claim 1. further comprising a reservoir cut valve, which is an electromagnetic valve provided in the reservoir fluid passage connecting the master cylinder and the reservoir,
The target electromagnetic valve is a simulator cut valve that prohibits the flow of fluid to the stroke simulator through the fluid path by closing the valve,
The control unit
In the pressurization process, the stroke simulator and the fluid path are pressurized by the pressurization/decompression device while maintaining a state in which the cutoff valve and the target solenoid valve are opened and the reservoir cut valve is closed,
In the depressurization process, the reservoir cut valve is opened while the shutoff valve and the target solenoid valve that were opened in the pressurization process are kept open, and the liquid path is depressurized by the pressurization/decompression device.
The vehicle braking device according to claim 4. further comprising a reservoir cut valve, which is an electromagnetic valve provided in the reservoir fluid passage connecting the master cylinder and the reservoir,
The target electromagnetic valve is a simulator cut valve that prohibits the flow of fluid to the stroke simulator through the fluid path by closing the valve,
The control unit closes the reservoir cut valve in the pressurization process and opens the reservoir cut valve in the decompression process.
The vehicle braking system according to claim 1. a simulator cut valve, which is an electromagnetic valve arranged in a portion between the target electromagnetic valve and the stroke simulator in the liquid path;
a master cut valve, which is a solenoid valve arranged in a portion between the target solenoid valve and the simulator cut valve in the liquid path;
further comprising
The target solenoid valve is disposed between the master cut valve and the pressure reducing device, and permits communication between the pressure reducing device and the first wheel cylinder while allowing communication between the pressure reducing device and the second wheel cylinder. A system shutoff valve that switches between communication and shutoff between
The control unit executes the pressurization process with the simulator cut valve, the master cut valve, and the system cutoff valve opened, and the simulator cut valve, the master cut valve, and the system cutoff valve. performing the depressurization process of depressurizing the liquid path with the pressurization and depressurization device in a state where the valve is open;
The vehicle braking system according to claim 1.

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