JP2022099361A - Vehicular braking device and electric cylinder - Google Patents

Abstract

To provide a vehicular braking device configured so that either of a first wheel cylinder and a second wheel cylinder can be pressurized, even when a liquid passage is broken.SOLUTION: The vehicular braking device comprises: an electric cylinder 2; a reservoir 45 that communicates with a liquid pressure chamber 24 in accordance with a position of a piston 23; a first liquid passage 51 through which a first wheel cylinder 81 is connected to the liquid pressure chamber 24; a second liquid passage 52 through which a second wheel cylinder 83 is connected to the liquid pressure chamber 24; a communication control valve 61 provided in the first liquid passage 51; a master cylinder 41 connected to the first liquid passage 51 through a master liquid passage 53; and a master cut valve 62 provided in the master liquid passage 53. In a cylinder 21 are formed a first output port 212 through which the first liquid passage 51 is communicated with the liquid pressure chamber 24, and a second output port 213 through which the second liquid passage 52 is communicated with the liquid pressure chamber 24, which is positioned upper than the first output port 212.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle braking device and an electric cylinder.

For example, the brake system disclosed in Japanese Patent No. 6202741 includes a reservoir, an electric cylinder, and a foil cylinder. In this system, the reservoir and the foil cylinder are connected via an electric cylinder. The fluid output from the electric cylinder is divided into two systems, is supplied to the first foil cylinder via one system, and is supplied to the second foil cylinder via the other system.

Japanese Patent No. 6202741

In the above system, for example, when the liquid passage connecting the electric cylinder and the foil cylinder is damaged, fluid leaks to the outside from the damaged portion. In this case, if the reservoir and the damaged part are hydraulically connected, all the fluid in the reservoir leaks from the damaged part, and air may enter the liquid passage and the electric cylinder connecting the reservoir and the electric cylinder. There is sex.

In the above system, in a state where the reservoir and the wheel cylinder are communicated via the electric cylinder (for example, while the vehicle is running where the electric cylinder is not operating), in the liquid passage connecting the wheel cylinder FR or RL and the electric cylinder. If fluid leakage occurs due to breakage, the fluid in the reservoir may become empty and air may enter the damaged liquid passage and the electric cylinder. When the brake operation is performed, the state of the switching valve is switched, and the damaged foil cylinder FR / RL side liquid passage and the normal foil cylinder FL / RR side liquid passage communicate with each other via the switching valve. .. As a result, the brake operation is performed with air mixed in the electric cylinder, and when the electric cylinder operates, the air also mixes in the liquid passage on the foil cylinder FL, RR side, and the foil cylinder FR, RL, FL, RR. There is a possibility that the foil pressure will not increase in all the foil cylinders.

An object of the present invention is to provide a vehicle braking device and an electric cylinder capable of pressurizing one of a first wheel cylinder and a second wheel cylinder even when the liquid passage is damaged.

The vehicle braking device of the present invention includes a cylinder and a piston that slides in the cylinder in response to the drive of an electric motor, and slides the piston from a hydraulic chamber partitioned by the cylinder and the piston. An electric cylinder configured to be able to supply fluid to the first wheel cylinder and the second wheel cylinder by motion, a reservoir communicating with the hydraulic chamber according to the position of the piston of the electric cylinder, and the first wheel cylinder. A first liquid passage connecting the hydraulic chamber and the hydraulic chamber, a second liquid passage connecting the second wheel cylinder and the hydraulic chamber, and a normally closed type electromagnetic valve provided in the first liquid passage. The communication control valve, the master cylinder connected to the portion of the first liquid passage between the first wheel cylinder and the communication control valve via the master liquid passage, and the master liquid passage are provided. A master cut valve, which is a normally open type electromagnetic valve, is provided, and the cylinder has a first output port for communicating the first liquid passage and the hydraulic chamber, and the second liquid passage and the liquid. A second output port, which is a port for communicating with the compression chamber and is arranged above the first output port when the electric cylinder is mounted on the vehicle, is formed.

The electric cylinder of the present invention includes a cylinder and a piston that slides in the cylinder in response to the drive of an electric motor, and the cylinder and the hydraulic chamber partitioned by the piston are slid by the piston. It is an electric cylinder configured to be able to supply fluid to the first wheel cylinder and the second wheel cylinder, and the cylinder communicates the first liquid passage connected to the first wheel cylinder and the hydraulic chamber. A first output port to be connected and a second output port which is a port for communicating the second liquid passage connected to the second wheel cylinder and the hydraulic chamber and is arranged above the first output port. , Are formed.

According to the vehicle braking device of the present invention, when fluid leakage occurs in the second liquid passage due to breakage in a state where the hydraulic chamber and the reservoir are in communication, air is discharged to the second liquid passage and the hydraulic chamber. It may be mixed. When air is mixed in the hydraulic pressure chamber, the air collects in the upper part of the hydraulic pressure chamber. As an example, when the brake operation is started, the master cut valve is closed, the communication control valve is opened, and the piston of the electric cylinder advances. When the communication control valve is opened, the first liquid passage and the second liquid passage communicate with each other via the hydraulic pressure chamber. According to the present invention, even if the brake operation is started with air mixed in the hydraulic pressure chamber, the first output port is arranged below the second output port, so that the upper side of the hydraulic pressure chamber is above. The air accumulated in is discharged from the second output port to the second liquid passage, and is unlikely to flow out from the first output port to the first liquid passage. That is, even if the brake operation is started in a state where the second liquid passage is damaged and air is mixed in, the mixing of air into the first liquid passage is suppressed. After that, for example, when an abnormality is detected because the hydraulic pressure in the hydraulic pressure chamber does not rise, the master cut valve is opened and the communication control valve is closed. As a result, fluid is supplied from the master cylinder to the first foil cylinder in response to the brake operation via the first liquid passage and the master liquid passage in which air is not mixed, and the foil pressure is increased.

If the brake is not operated, the master cut valve is open and the communication control valve is closed, and fluid leakage occurs due to breakage in the first liquid passage, the first liquid passage and the master liquid passage will be affected. Air may get mixed in. According to the present invention, even if the brake operation is started and the communication control valve is opened with air mixed in the first liquid passage and the master liquid passage, the fluid is controlled to communicate from the hydraulic chamber by advancing the piston. Since the air is discharged toward the valve, it is possible to prevent air from entering the hydraulic chamber from the first liquid passage. That is, even if the brake operation is started in a state where the first liquid passage is damaged and air is mixed, the fluid flow is in the direction from the hydraulic chamber to the first liquid passage, so that the air to the second liquid passage is obtained. Mixing is suppressed. After that, for example, when an abnormality is detected because the hydraulic pressure in the hydraulic pressure chamber does not rise, the master cut valve is opened and the communication control valve is closed. As a result, fluid is supplied from the electric cylinder to the second foil cylinder in response to the brake operation via the second liquid passage in which air is not mixed, and the foil pressure is increased.

As described above, according to the vehicle braking device of the present invention, when the fluid leakage due to breakage occurs in the second liquid passage while the electric cylinder and the reservoir are in communication with each other, or the brake is not operated. Even if fluid leakage occurs due to breakage in the first liquid passage while the master cut valve is open and the communication control valve is closed, one of the first wheel cylinder and the second wheel cylinder is pressurized. It can be possible. Further, according to the electric cylinder of the present invention, the same effect as described above can be exhibited by applying it to a braking device for a vehicle.

It is a block diagram of the braking device for a vehicle of this embodiment. It is a block diagram of the electric cylinder of this embodiment. It is a block diagram of the downstream unit of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the vehicle braking device 1 includes an upstream unit 11, a downstream unit 3, a first brake ECU 901, and a second brake ECU 902. The vehicle braking device 1 is a device capable of supplying fluid to the first wheel cylinders 81 and 82 and the second wheel cylinders 83 and 84 provided on the wheels of the vehicle. For example, the first foil cylinders 81 and 82 are provided on the front wheels, and the second foil cylinders 83 and 84 are provided on the rear wheels. 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, an electric cylinder 2, a first liquid passage 51, a second liquid passage 52, and a master liquid passage 53. , A reservoir liquid passage 54, a master cut valve 62, a communication control valve 61, a stroke sensor 71, pressure sensors 72 and 73, and a level switch 74. 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 according to the brake operation of the driver. The master cylinder device 4 includes a master cylinder 41, a master piston 42, a master chamber 41a, and an urging member 41b. The master cylinder 41 is a bottomed cylindrical member. The master cylinder 41 is formed with an input port 411 and an output port 412. The input port 411 and the output port 412 will be described later.

The master piston 42 is a piston member arranged in the master cylinder 41 and is mechanically connected to the brake pedal Z. The master piston 42 slides in the master cylinder 41 in response to the operation of the brake pedal Z. A through hole 421 is formed in the master piston 42. The master piston 42 is urged toward the initial position by the urging member 41b 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 41a is formed in the master cylinder 41 by the master cylinder 41 and the master piston 42. In the present embodiment, the number of master chambers 41a formed in the master cylinder 41 is one. The volume of the master chamber 41a changes according to the movement of the master piston 42. When the master piston 42 moves to one side in the axial direction, the volume of the master chamber 41a becomes smaller and the hydraulic pressure of the master chamber 41a (hereinafter referred to as “master pressure”) increases.

The urging member 41b is a spring member provided in the master chamber 41a. When no force is applied to the master piston 42, the master piston 42 is located at the initial position. The stroke simulator 43 is connected to the master cylinder device 4 via the simulator cut valve 44. The stroke simulator 43 is a device that generates a reaction force (load) with respect to the operation of the brake pedal Z. The stroke simulator 43 includes a cylinder, a piston, and an urging member. The stroke simulator 43 is connected to the output port 412 of the master cylinder 41 via the liquid passage 43a.

The simulator cut valve 44 is a normally closed solenoid valve provided in the liquid passage 43a. When the brake pedal Z is operated while the master cut valve 62, which will be described later, is closed and the simulator cut valve 44 is open, a pedal reaction force is generated by the stroke simulator 43.

The reservoir 45 stores the fluid. The pressure in the reservoir 45 is maintained at atmospheric pressure. Inside the reservoir 45, two storage chambers 451 and 452, each of which stores fluid, are formed.

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 located in the initial position, the storage chamber 451 is hydraulically connected to the master chamber 41a via the input port 411 and the through hole 421. When the master piston 42 advances by a predetermined amount, the input port 411 and the through hole 421 are hydraulically disconnected. In this case, the master chamber 41a and the reservoir 45 are hydraulically shut off. The storage chamber 452 is connected to the electric cylinder 2 via the reservoir liquid passage 54. The reservoir 45 may be composed of two separate reservoirs instead of the two storage chambers.

The electric cylinder 2 includes a cylinder 21, an electric motor 22, a piston 23, a hydraulic 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. Hereinafter, in the description of the electric cylinder 2, the moving direction of the piston 23 in which the volume of the hydraulic chamber 24 is small is defined as the front, and the opposite direction is defined as the rear.

The cylinder 21 is a bottomed cylindrical member or portion. The cylinder 21 is formed by utilizing, for example, a part of a housing (metal block). The cylinder 21 is formed with an input port 211, a first output port 212, and a second output port 213. As shown in FIG. 2, the input port 211 is an opening, and is formed between the seal member X1 provided on the cylinder 21 and the seal member X2. The seal member X1 and the seal member X2 are annular seal members, and their cross sections have a concave shape that opens forward (in other words, a convex arc shape that swells backward). Therefore, the seal member X1 allows the flow of fluid from the input port 211 to the hydraulic chamber 24 when the hydraulic pressure chamber 24 becomes negative pressure, and when the hydraulic pressure chamber 24 is equal to or higher than the atmospheric pressure, the hydraulic pressure is increased. The flow of fluid from the chamber 24 to the input port 211 is prohibited. The seal members X1 and X2 are arranged in an annular groove formed on the inner peripheral surface of the cylinder 21. The first output port 212 and the second output port 213 (hereinafter, also referred to as "output port 212, 213") are openings and are formed in front of the input port 211. The output ports 212 and 213 will be described later.

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 bottomed cylindrical member and slides in the cylinder 21 by being driven by an electric motor 22. A through hole 231 is formed in the piston 23. The through hole 231 communicates with the input port 211 when the piston 23 is located at the initial position.

The hydraulic chamber 24 is partitioned by a cylinder 21 and a piston 23, and the volume changes according to the movement of the piston 23. The initial position of the piston 23 is the position where the volume of the hydraulic chamber 24 is maximized (see FIG. 2).

The hydraulic chamber 24 can communicate with the reservoir 45 via the input port 211. Specifically, when the piston 23 is located in the initial position, it is hydraulically connected to the reservoir 45 via the through hole 231 and the input port 211. When the through hole 231 and the input port 211 do not communicate with each other, the hydraulic chamber 24 and the reservoir 45 are hydraulically cut off.

The urging member 25 is a spring that is arranged in the hydraulic chamber 24 and urges the piston 23 toward the initial position. When the electric motor 22 is not driven, the piston 23 is positioned at the initial position due to the urging force of the urging member 25.

When the piston 23 is located in the initial position, the hydraulic chamber 24 is connected to the reservoir 45 via the input port 211, the through hole 231 and the reservoir liquid passage 54. When the piston 23 moves forward by a predetermined amount due to the drive of the electric motor 22, the communication between the input port 211 and the through hole 231 is cut off. In this case, the hydraulic chamber 24 is hydraulically disconnected from the reservoir 45. In this way, the hydraulic chamber 24 and the reservoir 45 communicate with each other in a state (predetermined state) in which the piston 23 is located in the communication region from the initial position to the predetermined position with respect to the cylinder 21. When the piston 23 slides so as to make the hydraulic chamber 24 smaller while the hydraulic chamber 24 and the reservoir 45 are not hydraulically connected, the fluid flows from the hydraulic chamber 24 via the first output port 212. Is supplied to the first liquid passage 51, and is supplied to the second liquid passage 52 via the second output port 213.

As described above, in the electric cylinder 2, the input port 211 is opened by the piston 23 when the relative position of the piston 23 with respect to the cylinder 21 is a predetermined open position, and the relative position of the piston 23 with respect to the cylinder 21 is a predetermined closed position. The input port 211 is configured to be closed by the piston 23 in some cases.

(Liquid channel, etc.)
The first liquid passage 51 is a liquid passage connecting the first foil cylinders 81 and 82 and the hydraulic chamber 24. The first liquid passage 51 is connected to the downstream unit 3 (the first hydraulic pressure output unit 31 described later). Therefore, the first liquid passage 51 connects the first foil cylinders 81 and 82 and the hydraulic chamber 24 via the downstream unit 3. The hydraulic pressure generated in the hydraulic pressure chamber 24 is supplied to the downstream unit 3 via the first liquid passage 51.

The communication control valve 61 is a normally closed type solenoid valve provided in the first liquid passage 51. The communication control valve 61 is provided in the portion of the first liquid passage 51 between the hydraulic chamber 24 and the downstream unit 3. The communication control valve 61 closes in the non-energized state.

The second liquid passage 52 is a liquid passage connecting the second foil cylinders 83 and 84 and the hydraulic chamber 24. The second liquid passage 52 is connected to the downstream unit 3 (second hydraulic pressure output unit 32 described later). Therefore, the second liquid passage 52 connects the second foil cylinders 83 and 84 and the hydraulic chamber 24 via the downstream unit 3. The hydraulic pressure generated in the hydraulic pressure chamber 24 is supplied to the downstream unit 3 via the second liquid passage 52.

The master liquid passage 53 is a liquid passage that connects the master cylinder 41 and a portion of the first liquid passage 51 between the first foil cylinders 81 and 82 and the communication control valve 61. The portion of the first liquid passage 51 to which the master liquid passage 53 is connected is referred to as a connecting portion 50. The master liquid passage 53 is connected to the master chamber 41a via the output port 412. When the master piston 42 slides so as to make the master chamber 41a smaller while the master chamber 41a and the reservoir 45 are not hydraulically connected, the master chamber 41a is connected to the master liquid passage 53 via the output port 412. Fluid is supplied. The hydraulic pressure generated in the master chamber 41a is supplied to the downstream unit 3 via the master liquid passage 53 and the first liquid passage 51.

The master cut valve 62 is a normally open type solenoid valve provided in the master liquid passage 53. The master cut valve 62 opens when it is not energized. When the master cut valve 62 is closed, the master cylinder device 4 and the downstream unit 3 are hydraulically shut off.

The pressure sensor 72 is provided on the master cylinder device 4 side of the master cut valve 62 in the master liquid passage 53. The pressure sensor 72 detects the pressure in the master liquid passage 53. 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 in the master chamber 41a.

The pressure sensor 73 is a sensor that detects the pressure in the second liquid passage 52. In a state where the control mode of the vehicle braking device 1 is the brake-by-wire mode (hereinafter referred to as “by-wire mode”) described later, the hydraulic pressure detected by the pressure sensor 73 corresponds to the output pressure of the electric cylinder 2.

The stroke sensor 71 detects the stroke of the brake pedal Z. In this embodiment, two stroke sensors 71 are provided. The data detected by the two stroke sensors 71 is transmitted to the brake ECUs 901 and 902. The brake ECUs 901 and 902 acquire stroke information from the corresponding stroke sensors 71, respectively.

The level switch 74 is provided in the reservoir 45 and detects that the liquid level of the reservoir 45 has fallen below a predetermined position. When the liquid level of the reservoir 45 becomes less than a predetermined value, the level switch 74 transmits data indicating that the liquid level has dropped to the first brake ECU 901.

(Downstream unit)
Next, the downstream unit 3 will be described with reference to FIG. The downstream unit 3 is a so-called ESC actuator, and can independently regulate the hydraulic pressure of each of the foil cylinders 81 to 84. Specifically, in the downstream unit 3, the first hydraulic pressure output unit 31 configured to be able to adjust the pressure of the first wheel cylinders 81 and 82 and the second wheel cylinder 83 and 84 configured to be able to adjust the pressure are second. A hydraulic pressure output unit 32 is provided. Hereinafter, in the description of the downstream unit 3, the position of the upstream unit 11 with respect to the downstream unit 3 is referred to as upstream, and the positions of the foil cylinders 81 to 84 with respect to the downstream unit 3 are referred to as downstream.

The first hydraulic pressure output unit 31 is connected to the first liquid passage 51 extending from the upstream unit 11 on the upstream side, and is connected to the first foil cylinders 81 and 82 on the downstream side. The second hydraulic pressure output unit 32 is connected to the second liquid passage 52 extending from the upstream unit 11 on the upstream side, and is connected to the second foil cylinders 83 and 84 on the downstream side. The first hydraulic pressure output unit 31 and the second hydraulic pressure output unit 32 are independent of each other on the hydraulic pressure circuit in the downstream unit 3.

The fluid is supplied to the first hydraulic pressure output unit 31 from the upstream unit 11. The first hydraulic pressure output unit 31 is configured to be able to increase the hydraulic pressure of the first foil cylinders 81 and 82 based on the basic hydraulic pressure generated by the upstream unit 11. The first hydraulic pressure output unit 31 is configured to pressurize the first wheel cylinders 81 and 82 by generating a differential pressure between the input hydraulic pressure and the hydraulic pressures of the first wheel cylinders 81 and 82. ing.

The first hydraulic pressure output unit 31 includes a liquid passage 311, a pump liquid passage 315a, a pressure sensor 75, a differential pressure control valve 312, a check valve 312a, a holding valve 313, a check valve 313a, and a pressure reducing liquid passage. It includes a 314a, a pressure reducing valve 314, a pump 315, an electric motor 316, a reservoir 317, and a recirculation liquid passage 317a.

The liquid passage 311 is a liquid passage connecting the first liquid passage 51 extending from the upstream unit 11 and the first foil cylinder 81. The liquid passage 311 includes a branch portion X connected to the pump liquid passage 315a. The liquid passage 311 is a branch portion X, and branches into a liquid passage connected to one first foil cylinder 81 and a liquid passage connected to the other first foil cylinder 82. Since the configurations of the liquid passages 311 on the two liquid passages are the same, only the liquid passages connected to the first foil cylinder 81 will be described (referred to as the liquid passages 311).

The pressure sensor 75 is provided on the upstream unit 11 side of the differential pressure control valve 312 in the liquid passage 311. The pressure sensor 75 detects the pressure in the liquid passage 311. The pressure detected by the pressure sensor 75 corresponds to the hydraulic pressure input from the first liquid passage 51 of the upstream unit 11 to the first hydraulic pressure output unit 31. The data detected by the pressure sensor 75 is transmitted to the second brake ECU 902.

The differential pressure control valve 312 is a normally open type linear solenoid valve provided between the branch portion X and the pressure sensor 75 in the liquid passage 311. By controlling the opening degree of the differential pressure control valve 312, it is possible to generate a differential pressure between the upstream and downstream sides of the differential pressure control valve 312. The check valve 312a is provided in parallel with the differential pressure control valve 312. The check valve 312a is configured to allow only fluid flow from the upstream side to the downstream side.

The holding valve 313 is a normally open type solenoid valve provided between the branch portion X and the foil cylinder 81 in the liquid passage 311. The check valve 313a is provided in parallel with the holding valve 313. The check valve 313a is configured to allow only fluid flow from the downstream side to the upstream side.

The pressure reducing liquid passage 314a is a liquid passage connecting the portion of the liquid passage 311 between the holding valve 313 and the foil cylinder 81 and the reservoir 317. A pressure reducing valve 314 is provided in the pressure reducing liquid passage 314a.

The pressure reducing valve 314 is a normally closed type solenoid valve provided in the pressure reducing liquid passage 314a. When the pressure reducing valve 314 is in the valve open state, the fluid in the foil cylinder 81 can flow into the reservoir 317 via the pressure reducing liquid passage 314a. Therefore, the pressure of the foil cylinder 81 can be reduced by opening the pressure reducing valve 314.

The reservoir 317 is a well-known pressure-regulating reservoir for storing fluid, and is connected to a decompression fluid passage 314a and a reflux fluid passage 317a. The reflux liquid passage 317a is a liquid passage that connects a portion of the liquid passage 311 between the pressure sensor 75 and the differential pressure control valve 312 and the reservoir 317. The fluid in the reservoir 317 is sucked by the operation of the pump 315. When the amount of fluid in the reservoir 317 decreases, the valve in the reservoir 317 opens, and the fluid is supplied to the reservoir 317 from the first liquid passage 51 of the upstream unit 11 via the reflux liquid passage 317a.

The pump liquid passage 315a is a liquid passage that connects a portion of the pressure reducing liquid passage 314a between the pressure reducing valve 314 and the reservoir 317 and a branch portion X of the liquid passage 311. A pump 315 is provided in the pump liquid passage 315a.

The pump 315 is a pump that operates in response to the drive of the electric motor 316, and is, for example, a well-known piston pump or gear pump. The suction side of the pump 315 is connected to the reservoir 317, and the discharge side of the pump 315 is connected to the branch portion X. When the pump 315 is activated, the fluid in the reservoir 317 is sucked in to supply the fluid to the branch X.

The first hydraulic pressure output unit 31 is configured to be able to pressurize the first wheel cylinders 81 and 82 based on the hydraulic pressure input from the upstream side by operating various solenoid valves and pumps. Since the second hydraulic pressure output unit 32 has the same configuration as the first hydraulic pressure output unit 31 except that the pressure sensor 75 is not provided, the description thereof will be omitted. Like the first hydraulic pressure output unit 31, the second hydraulic pressure output unit 32 is also configured to be able to pressurize the second wheel cylinders 83 and 84 based on the basic hydraulic pressure.

(Brake ECU)
The first brake ECU 901 and the second brake ECU 902 (hereinafter, also referred to as "brake ECUs 901 and 902") are electronic control units including a CPU and a memory, respectively. Each brake ECU 901, 902 includes 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 to each other so that information (control information, etc.) can be communicated 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 is configured to be able to control the electric cylinder 2 and the solenoid valves 61, 62, 44 based on the data detected by the plurality of sensors 71, 72, 73, 74 of the upstream unit. ing. The first brake ECU 901 can calculate each foil 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 the data detected by the stroke sensor 71 and the pressure sensor 75. The second brake ECU 902 also receives data detected by a wheel speed sensor (not shown), an acceleration sensor (not shown), or the like provided in the vehicle. When the second brake ECU 902 pressurizes the first wheel cylinder 81 by the downstream unit 3, the second brake ECU 902 responds to the target differential pressure (hydraulic pressure of the first wheel cylinder 81> hydraulic pressure of the first liquid passage 51) in the differential pressure control valve 312. The control current is applied to close the differential pressure control valve 312. At this time, the holding valve 313 is open and the pressure reducing valve 314 is closed. Further, by operating the pump 315, the fluid is supplied from the first liquid passage 51 to the branch portion X via the reservoir 317. As a result, the first foil cylinder 81 is pressurized.

When the wheel pressure is reduced by the downstream unit 3 by anti-skid control or the like, the second brake ECU 902 operates the pump 315 in a state where the pressure reducing valve 314 is opened and the holding valve 313 is closed, and the first wheel cylinder is operated. Pump back the fluid in 81. The second brake ECU 902 closes the holding valve 313 and the pressure reducing valve 314 when the foil pressure is held by the downstream unit 3. When the foil pressure is pressurized or reduced only by the operation of the electric cylinder 2 or the master cylinder device 4, the second brake ECU 902 opens the differential pressure control valve 312 and the holding valve 313, and closes the pressure reducing valve 314.

The second brake ECU 902 can calculate each foil pressure based on the control state of the pressure sensor 75 and the downstream unit 3. The detected values of the various sensors may be transmitted to both brake ECUs 901 and 902.

The vehicle braking device 1 is configured to be capable of executing 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 a hydraulic pressure to the foil cylinders 81 to 84 based on the output pressure of the upstream unit 11. Hereinafter, normal control will be described.

The first brake ECU 901 includes a control unit 91 that controls an upstream unit 11 including an electric motor 22 and the like. The normal control is a control in which the master cylinder device 4 and the foil cylinders 81 to 84 are hydraulically shut off, and the foil cylinders 81 to 84 are pressurized by at least one of the electric cylinder 2 and the downstream unit 3.

The control unit 91 executes normal control at a predetermined timing, first closes the master cut valve 62, and opens the communication control valve 61 and the simulator cut valve 44. The predetermined timing is, for example, the timing at which the brake operation is started. In normal control, the control unit 91 sets the target output pressure based on the data detected by the stroke sensor 71 and the pressure sensor 72. The control unit 91 controls the electric cylinder 2 based on the set target output pressure. The second brake ECU 902 operates the downstream unit 3 when executing anti-skid control or the like. As described above, in the normal control, the electric cylinder 2, the first hydraulic pressure output unit 31, and the second hydraulic pressure output unit 32 are controlled based on the set target value, so that the liquids in the foil cylinders 81 to 84 are liquid. The pressure can be adjusted.

Further, if the output pressure (for example, the detected value of the pressure sensor 73) does not increase even though the electric cylinder 2 is operating, the first brake ECU 901 determines that an abnormality has occurred and controls the mode. Switch from by-wire mode to non-by-wire mode. The non-by-wire mode is a state in which the communication control valve 61 is closed, the master cut valve 62 is opened, and the simulator cut valve 44 is closed. Further, when the liquid level of the reservoir 45 drops and the level switch 74 detects an abnormality, the control mode is maintained in the non-by-wire mode even when the brake operation is started.

(Output port of electric cylinder)
The output ports 212 and 213 of the electric cylinder 2 will be further described. In the description, in the state where the electric cylinder 2 is mounted on the vehicle, the upper part in the vertical direction is referred to as "upper" and the lower part in the vertical direction is referred to as "lower". In the present embodiment, when the vehicle braking device 1 is mounted on the vehicle, the direction in which the central axis of the cylinder 21 of the electric cylinder 2 extends is substantially the same as the front-rear direction of the vehicle (see FIG. 2). The plane that passes through the central axis of the cylinder 21 and is orthogonal to the vertical direction in the vehicle is defined as the virtual horizontal plane V.

As shown in FIGS. 1 and 2, the first output port 212 is a port that allows the first liquid passage 51 and the hydraulic chamber 24 to communicate with each other. The second output port 213 is a port for communicating the second liquid passage 52 and the hydraulic chamber 24, and is located above the first output port 212. In the present embodiment, the first output port 212 is formed at the lower end of the cylinder 21. The second output port 213 is formed at the upper end of the cylinder 21. The output ports 212 and 213 are formed at the front end of the cylinder 21 (hydraulic chamber 24).

(Summary of composition)
The vehicle braking device 1 of the present embodiment includes a cylinder 21 and a piston 23 that slides in the cylinder 21 in response to the drive of the electric motor 22, and is a hydraulic chamber 24 partitioned by the cylinder 21 and the piston 23. Therefore, the electric cylinder 2 configured to be able to supply fluid to the first wheel cylinders 81, 82 and the second wheel cylinders 83, 84 by sliding the piston 23, and the hydraulic pressure according to the position of the piston 23 of the electric cylinder 2. A reservoir 45 communicating with the chamber 24, a first liquid passage 51 connecting the first wheel cylinders 81 and 82 and the hydraulic chamber 24, and a second connecting the second wheel cylinders 83 and 84 and the hydraulic chamber 24. Between the liquid passage 52, the communication control valve 61 which is a normally closed type electromagnetic valve provided in the first liquid passage 51, and the first wheel cylinders 81 and 82 of the first liquid passage 51 and the communication control valve 61. A master cylinder 41 connected to the portion via a master liquid passage 53 and a master cut valve 62 which is a normally open type electromagnetic valve provided in the master liquid passage 53 are provided, and the cylinder 21 is provided with a first cylinder. A first output port 212 for communicating the hydraulic passage 51 and the hydraulic chamber 24, and a port for communicating the second hydraulic passage 52 and the hydraulic chamber 24, and the first in a state where the electric cylinder 2 is mounted on the vehicle. A second output port 213 located above the output port 212 is formed.

(Effect of this embodiment)
According to the vehicle braking device 1 of the present embodiment, when fluid leakage occurs in the second liquid passage 52 in a state where the hydraulic pressure chamber 24 and the reservoir 45 are in communication with each other, the second liquid passage 52 and the second liquid passage 52 and the second liquid passage 52 and the second liquid passage 52 are damaged. Air may enter the hydraulic chamber 24. The breakage can occur, for example, in the liquid passage between the downstream unit 3 and the foil cylinders 83, 84, or in the liquid passage between the upstream unit 11 and the downstream unit 3. When a fluid leak occurs due to breakage in the second liquid passage 52, the liquid level of the fluid in the reservoir 45 drops, and by detecting this with the level switch 74, the occurrence of the fluid leak can be detected, and the level switch 74 When a decrease in the liquid level of the fluid in the reservoir 45 is detected in, the control mode is switched to the non-by-wire mode, and even if the brake operation is performed, the master cut valve 62 is opened and the communication control valve 61 is closed. Will be done. Since the communication control valve is closed, even if air is mixed in the hydraulic chamber 24, it is possible to prevent air from entering the first liquid passage 51. However, if the level switch 74 does not function due to a failure or the like, an abnormal decrease in the fluid of the reservoir 45 cannot be detected. When air is mixed in the hydraulic chamber 24, the air collects in the upper part of the hydraulic chamber 24, for example, as schematically represented by the two-dot chain line in FIG. 2. When the brake operation is started (when the brake pedal Z is operated), the normal control is executed by the by-wire mode as described above. When the communication control valve 61 is opened, the first liquid passage 51 and the second liquid passage 52 communicate with each other via the hydraulic pressure chamber 24.

According to the present embodiment, even if the brake operation is started in a state where the level switch 74 does not function and air is mixed in the hydraulic chamber 24, the first output port 212 is lower than the second output port 213. The air accumulated above the hydraulic pressure chamber 24 flows out from the second output port 213 to the second liquid passage 52, and is unlikely to flow out from the first output port 212 to the first liquid passage 51. .. That is, even if the brake operation is started in a state where the second liquid passage 52 is damaged and air is mixed in, the mixing of air into the first liquid passage 51 is suppressed. After that, when an abnormality is detected because the hydraulic pressure in the hydraulic chamber 24 does not rise, the control mode is switched to the non-by-wire mode, the master cut valve 62 is opened, and the communication control valve 61 is closed. As a result, fluid is supplied from the master cylinder 41 to the first foil cylinders 81 and 82 in response to the brake operation via the first liquid passage 51 and the master liquid passage 53 in which air is not mixed, and the foil pressure rises. do.

The first is in a non-by-wire mode in which the brake is not operated (a mode in which the master cut valve is open and the communication control valve is closed) and the master chamber 41a and the reservoir 45 are in communication with each other. If fluid leakage occurs in the liquid passage 51 due to breakage, air may be mixed into the first liquid passage 51 and the master liquid passage 53. According to the present embodiment, even if the brake operation is started, the master cut valve 62 is closed, and the communication control valve 61 is opened with air mixed in the first liquid passage 51 and the master liquid passage 53. Since the fluid is discharged from the hydraulic chamber 24 toward the communication control valve 61 by the advancement of the piston 23, it is suppressed that air is mixed into the hydraulic chamber 24 from the first liquid passage 51. That is, even if the brake operation is started in a state where the first liquid passage 51 is damaged and air is mixed in, the flow of the fluid is in the direction from the hydraulic chamber 24 to the first liquid passage 51, so that the second liquid passage Mixing of air into 52 is suppressed. After that, when an abnormality is detected because the hydraulic pressure in the hydraulic pressure chamber 24 does not rise, the master cut valve 62 is opened and the communication control valve 61 is closed. As a result, fluid is supplied from the electric cylinder 2 to the second foil cylinders 83 and 84 in response to the brake operation via the second liquid passage 52 in which air is not mixed, and the foil pressure is increased.

As described above, according to the vehicle braking device 1, even if the liquid passage is damaged, one of the first foil cylinders 81 and 82 and the second foil cylinders 83 and 84 can be pressurized.

In the present embodiment, the first output port 212 is provided at the lower end of the cylinder 21, and it is more likely that the air collected in the upper part of the hydraulic chamber 24 will flow out from the first output port 212 to the first liquid passage 51. Effectively suppressed. Further, since the second output port 213 is provided at the upper end portion of the cylinder 21, the air bleeding work of the hydraulic chamber 24 becomes easy.

(others)
The present invention is not limited to the above embodiment. In the above embodiment, the virtual horizontal plane V is parallel to the front-rear direction of the vehicle. However, the central axis of the electric cylinder 2 may be angled with the front-rear direction of the vehicle when mounted on the vehicle. Even in this case, each port may be formed so that the second output port 213 is located above the first output port 212 in the state of being mounted on the vehicle. Further, for example, the positions of the output ports 212 and 213 are not limited to the upper and lower ends of the cylinder 21 as described above. For example, the first output port 212 is formed in the portion of the cylinder 21 between the virtual horizontal plane V and the lower end portion, and the second output port 213 is the portion of the cylinder 21 between the virtual horizontal plane V and the upper end portion. It may be formed in. That is, the first output port 212 may be arranged in the lower half portion of the cylinder 21, and the second output port 213 may be arranged in the upper half portion of the cylinder 21. It can be said that the first output port 212 may be arranged below the center of the cylinder, and the second output port 213 may be arranged above the center of the cylinder. According to this, it is possible to suitably suppress the outflow of air from the hydraulic pressure chamber 24 to the first liquid passage 51 through the first output port 212, and it is also possible to perform air bleeding work using the second output port 213. .. Both the output ports 212 and 213 may be arranged above or below the virtual horizontal plane V. Even in this case, the second output port 213 may be located above the first output port 212.

Further, the electric cylinder 2 has two output ports 212 and 213 formed so as to be vertically different from each other when mounted on a vehicle. In this way, the first output port 212 that communicates the first liquid passage 51 and the hydraulic chamber 24, and the port that communicates the second liquid passage 52 and the hydraulic chamber 24, rather than the first output port 212. According to the electric cylinder 2 provided with the second output port 213 located above, the same effect as that of the above embodiment can be exhibited by applying the electric cylinder 2 to the braking device for a vehicle. According to the electric cylinder 2 having this configuration, when the piston 23 advances, the mixing of air into the fluid discharged from the lower output port 213 is suppressed as compared with the upper output port 213. The output ports 212 and 213 can be formed on the peripheral surface and the end surface of the cylinder 21.

Further, the electric cylinder 2 does not have to be provided with the urging member 25. In this case, it is preferable that the energization configuration for the electric motor 22 is a redundant configuration. Further, the downstream unit 3 may be provided with an electric cylinder instead of the pump 315. The present invention can also be applied to, for example, a vehicle including a regenerative braking device (hybrid vehicle or electric vehicle), a vehicle that executes automatic brake control, or an automatically driven vehicle.

Further, in the above embodiment, the first wheel cylinders 81 and 82 are provided on the front wheels and the second wheel cylinders 83 and 84 are provided on the rear wheels, but the first wheel cylinders 81 and 82 are provided on the right front wheel and the left rear wheel. The second wheel cylinders 83 and 84 may be provided on the left front wheel and the right rear wheel.

1 ... Vehicle braking device, 2 ... Electric cylinder, 21 ... Cylinder, 212 ... First output port, 213 ... Second output port, 22 ... Electric motor, 23 ... Piston, 24 ... Hydraulic chamber, 41 ... Master cylinder, 51 ... 1st liquid passage, 52 ... 2nd liquid passage, 53 ... master liquid passage, 61 ... communication control valve, 62 ... master cut valve.

Claims (3)

A cylinder and a piston that slides in the cylinder according to the drive of an electric motor are provided, and fluid is transferred from the hydraulic chamber partitioned by the cylinder and the piston to a first wheel cylinder by sliding the piston. An electric cylinder configured to be able to supply to the second wheel cylinder,
A reservoir that communicates with the hydraulic chamber according to the position of the piston of the electric cylinder,
A first liquid passage connecting the first foil cylinder and the hydraulic chamber,
A second liquid passage connecting the second foil cylinder and the hydraulic chamber,
A communication control valve, which is a normally closed solenoid valve provided in the first liquid passage,
A master cylinder connected to a portion of the first liquid passage between the first foil cylinder and the communication control valve via a master liquid passage,
A master cut valve, which is a normally open solenoid valve provided in the master liquid passage,
Equipped with
The cylinder has
A first output port that communicates the first liquid passage and the hydraulic chamber,
A second output port that is a port that communicates the second liquid passage and the hydraulic chamber and is located above the first output port when the electric cylinder is mounted on the vehicle.
Is formed, a braking device for vehicles. The first output port is arranged below the center of the cylinder among the cylinders.
The vehicle braking device according to claim 1, wherein the second output port is arranged above the center of the cylinder among the cylinders. A cylinder and a piston that slides in the cylinder according to the drive of an electric motor are provided, and fluid is transferred from the hydraulic chamber partitioned by the cylinder and the piston to a first wheel cylinder by sliding the piston. An electric cylinder configured to be able to supply to the second wheel cylinder.
The cylinder has
A first output port for communicating the first liquid passage connected to the first foil cylinder and the hydraulic chamber,
A second output port that communicates the second liquid passage connected to the second foil cylinder with the hydraulic chamber and is located above the first output port.
Is formed, an electric cylinder.

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