JP7315169B2 - brake structure for vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake structure that operates in an emergency.

2. Description of the Related Art Conventionally, many brake structures have been used in which hydraulic pressure for braking a wheel is generated by performing a braking operation on an operation input unit such as a brake pedal, and the hydraulic pressure is used to brake the wheel. In such a brake structure, various automatic brake structures have been proposed in which the wheels are braked by a driving control unit when a predetermined condition is satisfied regardless of the driver's will.

Patent Document 1 proposes a brake device for a vehicle that includes a first hydraulic pressure generating means that generates brake hydraulic pressure by braking operation and a brake path that supplies the brake hydraulic pressure to the brake device, and operates the brake device using hydraulic pressure generated by a second hydraulic pressure generating means that serves as a hydraulic pressure generation source for other on-vehicle hydraulic devices. According to this brake system, it is possible to obtain a device that brakes the wheels regardless of the driver's will without newly providing means for generating hydraulic pressure in addition to hydraulic pressure generating means for generating hydraulic pressure by braking operation.

JP-A-5-310118

However, in the conventional brake structure that can brake the wheel regardless of the driver's intention, when the wheel is braked regardless of the driver's braking operation, for example, various sensors and various control devices are used to detect whether or not a predetermined condition is satisfied.

In such a conventional structure, in order to brake the wheels regardless of the driver's will, electric power was essential to operate various sensors, control devices, and hydraulic devices. Therefore, for example, when the vehicle loses all power while it is running, there is a possibility that the vehicle cannot be stopped by appropriately braking the wheels.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a brake structure with a simple configuration that can stop a vehicle by braking wheels without using electric power when power is lost to an operation control unit for controlling braking of the wheels.

A brake structure for a vehicle according to the present invention, which achieves the above object, includes an operation pressure generation unit that generates an operation pressure based on a brake operation of an operation input unit;firstA brake structure for a vehicle, comprising: an operation pressure circuit that transmits by a working fluid; a brake main unit that brakes wheels by operation pressure from the operation pressure circuit; and an operation control unit that controls at least braking of the wheels, the brake structure comprising: an emergency drive source that generates driving force when electric power is lost;firstan emergency actuation part that generates an operating pressure in the working fluid and transmits it to the brake body part.The emergency drive source includes: a drive cylinder; a drive piston arranged to move back and forth within the drive cylinder to partition the drive cylinder chamber; a biasing portion that biases the drive piston in a direction to decrease the volume of the drive cylinder chamber; a supply passage connected to the drive cylinder chamber so as to supply the second working fluid from the reservoir; a drive pressure passage for guiding the second working fluid from the drive cylinder chamber to the emergency operation unit; It is configured to be transmitted to the emergency actuating part by the flow path.

In the present invention, preferably, the emergency actuation unit has a switching cylinder, a switching piston arranged to move back and forth in the switching cylinder, one switching chamber and the other switching chamber partitioned by the switching piston, the operation pressure circuit has an operation-side flow path connected to the operation pressure generation unit and a body-side flow path connected to the brake body, the operation-side flow path and the body-side flow path are connected in series via one of the switching chambers, and the emergency drive source is connected to the other switching chamber.

When the driving force generated by the emergency drive source is transmitted to the other switching chamber, the operation side passage is closed by the operation of the switching piston, and the operation pressure generated by the one switching chamber is transmitted to the brake main body through the main body side passage.

According to the brake structure for a vehicle of the present invention, the emergency drive source generates driving force at the time of power loss, and the emergency operating unit generates the operating pressure in the operating fluid of the operating pressure circuit from the driving force, and transmits the operating pressure to the brake body. Therefore, when power is no longer supplied to the operation control unit and various devices that make up the brake structure and control by the operation control unit becomes impossible, the wheels can be braked to stop the vehicle.

In the present invention, the drive force generated by the emergency drive source generates the operation pressure in the working fluid of the operation pressure circuit and transmits it to the brake main body. Therefore, the wheel can be braked when the power is lost by using the structure for braking the wheel by normal braking operation, and the brake structure can be obtained with a simple configuration. Therefore, it is possible to provide a simple brake structure that brakes the wheels to stop the vehicle without using power when power is lost.

In the brake structure for a vehicle of the present invention, one switching chamber and the other switching chamber are partitioned by a switching piston that can move back and forth in the switching cylinder of the emergency operation unit, and the operation-side flow path on the operation pressure generating unit side in the operation pressure circuit and the body-side flow path on the brake main body side are connected in series via one of the switching chambers, and an emergency drive source is connected to the other switching chamber.

In this case, when the driving force generated by the emergency drive source is transmitted to the other switching chamber, the switching piston closes the operation-side flow path, and the operation pressure generated by the driving force is transmitted from the body-side flow path to the brake main body.

In the brake structure for a vehicle of the present invention, it is preferable that the drive cylinder chamber is partitioned by the drive piston arranged in the drive cylinder which can move back and forth, the drive piston is urged by the urging portion in the direction of decreasing the volume of the drive cylinder chamber, and the electric portion moves in the direction of increasing the volume of the drive cylinder chamber and maintains this state when electric power is supplied, and allows the movement of the drive piston in the direction of decreasing the volume of the drive cylinder chamber when power is lost.

In this case, when the electric power is supplied, the driving piston is moved by the electric part to increase the biasing force of the biasing part, and the working fluid is sucked into the driving cylinder chamber from the driving fluid pressure circuit to maintain this state. Moreover, because of the structure in which the urging force is maintained by the electric portion, the fluid pressure in the drive cylinder chamber is kept sufficiently low, and there is no need for a structure that maintains the working fluid at high fluid pressure for a long period of time.

On the other hand, when power is lost, the driving piston is moved by the biasing force of the biasing portion to generate sufficient driving force and release it to the driving fluid pressure circuit. Therefore, the emergency actuation unit generates sufficient operation pressure from this driving force and transmits it through the operation pressure circuit, and the brake main unit brakes the wheels to provide an emergency drive source that generates sufficient operation pressure in the event of power loss.

It is a block diagram explaining the composition of the brake structure concerning the embodiment of the present invention. It is a block diagram showing a stopped state of the brake structure according to the present embodiment. FIG. 4 is a cross-sectional view of the poppet built-in switching valve in the emergency actuation section of the present embodiment, showing a state before the working fluid is supplied from the emergency actuation section. FIG. 4 is a block diagram showing a state in which the working fluid is sucked by the emergency operation unit in the embodiment; FIG. 4 is a block diagram showing a state after the emergency operation part releases working fluid in the emergency operation part; FIG. 11 is a cross-sectional view of the switching valve with built-in poppet in a state in which the operating fluid is supplied from the emergency operating section and the operation side flow path is blocked by the poppet; FIG. 4 is a cross-sectional view of the switching valve with a built-in poppet in a state in which an operating pressure generated by the supply of working fluid from the emergency operating section is transmitted to the body-side flow path; It is a schematic diagram which shows the modification of the emergency operation|movement part which concerns on the said embodiment, and shows the state before the working fluid from an emergency operation|movement part is supplied. It is a schematic diagram which shows the modification of the emergency operation|movement part which concerns on the said embodiment, and shows the state after the working fluid from an emergency operation|movement part is supplied.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a vehicle brake structure according to the present invention will be described in detail below.
As shown in FIG. 1, the vehicle of the present embodiment is provided with an operation control unit 10 that performs various controls such as braking of the wheels 15, and is provided with a brake structure 11 that can be operated by the operation of the driver and the control of the operation control unit 10.

The driving control unit 10 controls various devices used for running, turning, and stopping of the vehicle to perform manual driving, automatic driving, or unmanned driving. In this embodiment, the operation control unit 10 switches between the manual operation mode and the automatic operation mode. The operation control unit 10 is interlocked with the ignition switch 24, which is the main switch of the vehicle, and performs control operations when the ignition switch 24 is ON, and various settings and operations are performed.

The brake structure 11 is provided in front of the driver's seat of the vehicle and includes an operation input unit 21 for inputting a brake operation, an operation pressure generation unit 20 for generating an operation pressure based on the brake operation of the operation input unit 21, an operation pressure circuit 30 for transmitting the operation pressure, a brake main unit 22 for braking the wheels 15 by the operation pressure from the operation pressure circuit 30, and an operation assisting unit 23 for assisting the operation of various devices during brake operation.

The operation input unit 21 includes a brake pedal, etc., which is arranged at the foot of the driver's seat and receives a brake operation. The operation pressure generation unit 20 transmits or transmits the forward/backward movement input to the operation input unit 21, and based on this, generates the operation pressure made up of the working fluid pressure. In the present embodiment, a working fluid tank 29, a booster 35 that converts and amplifies input of forward/backward movement of the operation input unit 21 into working fluid pressure, and a master cylinder 36 that distributes the working fluid pressure are provided.

The operation pressure circuit 30 is a path that transmits the operation pressure of the operation pressure generating section 20 to the brake body section 22 . In this embodiment, two independent systems are provided, and an emergency brake unit 40 is provided in the middle of the route.

The brake body 22 brakes the wheels 15 by the operation pressure transmitted from the operation pressure circuit 30, and is equipped with an operation unit 37 such as a disc brake or a drum brake for braking each wheel 15.

The operation assisting unit 23 assists the operation of various devices when the brake is operated, and assists the operation of various devices for various purposes such as ensuring running stability, improving the stability of the vehicle body, and increasing the braking force when the brake is operated. In this embodiment, although detailed illustration is omitted, for example, a skid prevention mechanism and an ABS mechanism are installed.

The emergency brake unit 40 is composed of a fluid pressure device 25, and includes an emergency drive source 26 that retains the drive force during normal operation and generates drive force in an emergency, and an emergency operation unit 50 that generates operation pressure in the operating fluid of the operation pressure circuit 30 by the drive force from the emergency drive source 26 and transmits it to the brake body 22.

In the present embodiment, the normal state is when electric power is supplied to various devices such as the operation control unit 10 for controlling the braking of the wheels 15 and various devices constituting the brake structure 11. For example, when the vehicle is running due to the driver's driving operation, or when the vehicle is running while each unit is controlled by the operation control unit 10, the brake main unit 22 is actuated and each wheel 15 can be braked by the brake operation by the driver or the brake operation by the output from the operation control unit 10. In the present embodiment, the emergency is when power is lost, for example, when power is not supplied to various devices constituting the brake structure 11, such as the operation control unit 10 for controlling the braking of the wheels 15. It is when it occurs.

The emergency drive source 26 of the emergency brake unit 40 includes, as shown in FIG. 1, a fluid pressure device 25 having a hollow drive cylinder 41, a drive piston 44 disposed reciprocally in the drive cylinder 41 to partition the drive cylinder chamber 43, and a biasing portion 45 for axially biasing the drive piston 44 so as to reduce the volume of the drive cylinder chamber 43. Further, the emergency drive source 26 includes an electric portion 46 for axially driving or releasing the drive piston 44. The emergency drive source 26 is provided with a drive fluid pressure circuit 49 that connects between the drive cylinder chamber 43 of the fluid pressure device 25 and the emergency operation unit 50 and supplies and discharges working fluid to and from the drive cylinder chamber 43.

The emergency drive source 26 is provided with a drive source control section 28 , and its operation is controlled by the drive source control section 28 . The drive source control unit 28 receives from the operation control unit 10 identification information for emergency and normal operation, and information for switching between the automatic operation mode and the manual operation mode, and also receives energization information from the battery 16, ON information for the ignition switch 24, detection information for the drive piston 44 of the drive cylinder 41, and storage information for the working fluid in the buffer 61. Based on this information, the drive source control unit 28 controls the operations of the switching valve 66 and the electric unit 46, which will be described later, so that the emergency drive source 26 generates a drive force in a preset emergency.

The drive piston 44 is slidably in contact with the inner peripheral surface of the hollow portion 47 of the drive cylinder 41 via a sealing material, and is arranged so as to move forward and backward in the axial direction. The electric part 46 moves and maintains the driving piston 44 in the direction of increasing the volume of the driving cylinder chamber 43 when power is supplied, and allows the movement of the driving piston 44 in the direction of decreasing the volume of the driving cylinder chamber 43 when power is lost.

In the present embodiment, a detection unit 48 including a reed switch and a limit switch for detecting the position of the driving piston 44 of the driving cylinder 41 is mounted at the top dead center and the bottom dead center of the driving piston 44 of the driving cylinder 41 . Accordingly, by detecting the position of the driving piston 44, the suction and discharge of the working fluid in the driving cylinder 41 are detected.

The biasing portion 45 is made of, for example, a spring, and biases the drive piston 44 in a direction of decreasing the volume of the drive cylinder chamber 43, that is, toward the other end side. In this embodiment, the urging force of the urging portion 45 is set so as to obtain the flow rate and fluid pressure of the working fluid that realize the intended operation of the other fluid pressure devices 25 connected by the driving fluid pressure circuit 49 .

The biasing portion 45 of the present embodiment may be provided with a detection portion for directly or indirectly detecting the biasing force applied to the driving piston 44, and the biasing force of the biasing portion 45 may be detected as the position of the driving piston 44 or the like. In the operation control unit 10, when the biasing force of the biasing unit 45 is less than a predetermined value, automatic travel control is not executed.

The driving fluid pressure circuit 49 is connected to the driving cylinder chamber 43 so as to supply and discharge the working fluid, and includes a reservoir 60 consisting of an oil tank in which the working fluid is stored; a buffer 61 that communicates with the reservoir 60 and facilitates supply and recovery of a sufficient amount of the working fluid to the driving fluid pressure circuit 49; and a driving pressure flow path 63 that discharges and leads to the emergency operating unit 50 .

In the driving fluid pressure circuit 49 of the present embodiment, a switching valve 66 is provided as a switching portion that selectively switches between the supply flow path 62 and the driving pressure flow path 63 . The switching valve 66 is an electromagnetic valve that normally opens the supply channel 62 and closes the supply channel 62 in an abnormal state, that is, opens the supply channel 62 when energized and closes the supply channel 62 when not energized.

The electric portion 46 is interlocked with the ignition switch 24 of the vehicle and the switching of the automatic operation mode. On the other hand, when the ignition switch 24 is turned off, the automatic operation mode of the operation control unit 10 is canceled and the electric power of the electric unit 46 is cut off.

In the fluid pressure device 25 of the present embodiment, the working fluid pressure, discharge speed, and the like are appropriately adjusted by setting the correlation among the biasing force of the biasing portion 45, the moment of inertia of the drive piston 44, and the driving force of the electric portion 46 within a predetermined range.

On the other hand, the emergency actuation portion 50 of the emergency brake unit 40 is connected to the emergency drive source 26 comprising the fluid pressure device 25 via the drive fluid pressure circuit 49, as shown in FIGS. The emergency operating unit 50 has a poppet built-in switching valve 51 that is a so-called piston valve, and is provided in the middle of each path in the two operating pressure circuits 30 .

Each poppet built-in switching valve 51 includes a hollow switching cylinder 52, a switching piston 53 arranged in the switching cylinder 52 so as to be able to move back and forth along the axial direction, a first switching chamber 54 and a second switching chamber 55 separated by the switching piston 53, a second compression spring 57 that biases the switching piston 53 toward the second switching chamber 55, and a movement of the switching piston 53 toward the first switching chamber 54 along the axial direction with a stroke smaller than the stroke of the switching piston 53. and a first compression spring 56 that biases the poppet 58 toward the first switching chamber 54 with respect to the switching piston 53 .

In this embodiment, the operation pressure circuit 30 includes an operation-side flow path 31 connected to the operation pressure generating section 20 and a body-side flow path 32 connected to the brake main body 22. Both the operation-side flow path 31 and the body-side flow path 32 are connected to the first switching chamber 54 with openings, and the operation-side flow path 31 and the body-side flow path 32 are connected in series via the first switching chamber 54.

The body-side channel 32 is provided at a position that is always open within the first switching chamber 54 , and the operation-side channel 31 is provided at a position that can be closed by a poppet 58 within the first switching chamber 54 . Furthermore, the drive fluid pressure circuit 49 of the emergency drive source 26 is connected to the second switching chamber 55 at a position where it is normally open.

The operation of the brake structure 11 including the emergency drive source 26 and the emergency operation unit 50 will be described.
First, the ignition switch 24 is turned on in the automatic driving mode in order to automatically run the vehicle from the completely stopped state shown in FIG. As a result, electric power is supplied to each part, and the electric part 46 is energized and driven together with the operation control part 10 .

Then, as shown in FIG. 4, in the hollow portion 47 of the drive cylinder 41, when the electric portion 46 is driven, the drive piston 44 moves in the direction of increasing the volume of the drive cylinder chamber 43, and the working fluid stored in the buffer 61 from the storage portion 60 is supplied to the drive cylinder chamber 43 by the drive fluid pressure circuit 49 and sucked. At this time, the driving force of the electric portion 46 causes the driving piston 44 to move toward one end of the driving cylinder 41 against the biasing force of the biasing portion 45, thereby increasing the biasing force exerted by the biasing portion 45 on the driving piston 44. As a result, a sufficient amount of working fluid is stored in the driving cylinder chamber 43.

When the drive piston 44 cannot move due to the driving force of the electric part 46, the electric part 46 is stopped in the energized state, and the state is maintained. The operation control unit 10 executes control of automatic operation by transmitting information on the biasing force. By performing a prescribed operation, the vehicle runs unmanned and automatically, and the operation control unit 10 controls the running motion, turning motion, stopping motion, and the like of the vehicle.

In such a normal state, that is, in the emergency operation unit 50 in a normal energized state, as shown in FIG. Therefore, the operation pressure generated by the operation pressure generating section 20 is directly transmitted to the brake body section 22 from the operation side flow path 31 and the main body side flow path 32, so that each wheel 15 can be braked.

For example, when power is lost due to a situation in which power is not supplied to the operation control unit 10 while the vehicle is running, the electric power is not supplied to the electric unit 46 which is energized together with the operation control unit 10.例文帳に追加Then, as shown in FIG. 5 , in the fluid pressure device 25 , the motorized portion 46 is in a non-energized state, so that the movement of the drive piston 44 is permitted by releasing the regulation by the motorized portion 46 . Since the driving piston 44 is biased with a sufficient biasing force, the driving piston 44 moves in the direction of decreasing the volume of the driving cylinder chamber 43 due to this biasing force. As a result, the working fluid pressurized by the biasing force of the biasing portion 45 is discharged from the driving cylinder chamber 43 to the driving fluid pressure circuit 49 .

In the driving fluid pressure circuit 49, the switching valve 66 normally opens the supply channel 62 in an energized state, but closes the supply channel 62 when it becomes non-energized in an abnormal state. Therefore, the working fluid discharged from the driving cylinder chamber 43 and its pressure are transmitted to the emergency working part 50 through the driving pressure flow path 63 .

In the emergency operation unit 50, as shown in FIG. 6, the working fluid from the emergency drive source 26 is supplied to the second switching chamber 55 of the poppet built-in switching valve 51, and the driving force generated by the emergency drive source 26 is transmitted to the second switching chamber 55. As a result, the switching piston 53 moves toward the first switching chamber 54 , and the poppet 58 closes the opening of the operation-side flow path 31 . After that, as shown in FIG. 7, the working fluid from the emergency drive source 26 is further supplied to the second switching chamber 55 of the switching valve 51 with a built-in poppet, thereby discharging the working fluid contained in the first switching chamber 54 to the body side flow path 32. As a result, the operating pressure generated by the drive pressure of the emergency drive source 26 is transmitted to the brake body portion 22 via the body-side passage 32 . In this embodiment, the operation pressure is transmitted to the brake main body 22 after being adjusted by the motion assisting section 23, and the wheels 15 are braked by the motion section 37 to stop the running of the vehicle.

In this embodiment, various fail-safe mechanisms are provided to prevent malfunction of the brake structure 11 . For example, since the detection unit 48 is attached to the drive cylinder 41, if the detection unit 48 detects discharge of the working fluid in the drive cylinder 41 during normal operation, the drive cylinder 41 and the control system malfunction. In this case, the switching valve 66 keeps the supply channel 62 open. This prevents the working fluid from being supplied to the drive pressure flow path 63 side, and prevents the wheels 15 from being braked due to malfunction in the normal state.
Also, when the working fluid leaks from the storage portion 60, the drive cylinder chamber 43, or the like, a change in the detection portion 48 of each portion is detected in normal times. When an abnormality occurs in the electric part 46, it is discovered by detecting an abnormal change in the detection part 48 of each part. A failure of the detection unit 48 or a failure of the urging unit 45 can be detected by the operation when the ignition switch 24 is turned on or when the ignition switch 24 is turned off.

According to the brake structure 11 of the present embodiment, the emergency drive source 26 generates a driving force when power is lost, and the emergency operation unit 50 generates operation pressure in the working fluid of the operation pressure circuit 30 from this driving force, and transmits the operation pressure to the brake body 22. Therefore, when electric power is no longer supplied to various devices having a brake structure 11 including the operation control unit 10 for controlling the braking of the wheels 15, and control by the operation control unit 10 becomes impossible, the wheels 15 can be braked to stop the vehicle.

Moreover, since the driving force generated by the emergency drive source 26 generates the operation pressure in the working fluid of the operation pressure circuit 30 and transmits it to the brake main body 22, the structure for braking the wheels 15 in the event of electric power loss is provided with a simple configuration using the structure for braking the wheels 15 by normal braking operation. Therefore, a simple brake structure 11 is realized that can stop the vehicle by braking the wheels 15 without using electric power when electric power is lost.

According to the brake structure 11 of the present embodiment, the emergency operation unit 50 is partitioned into the first switching chamber 54 and the second switching chamber 55 by the switching piston 53 that can move back and forth in the switching cylinder 52. The first switching chamber 54 is connected in series with the operation side passage 31 on the side of the operation pressure generating portion 20 in the operation pressure circuit 30 and the main body side passage 32 on the side of the brake main body 22 via the first switching chamber 54. The second switching chamber 55 is connected with the emergency drive source 26. are Therefore, a structure for generating the operating pressure in the working fluid of the operating pressure circuit 30 by the driving force generated by the emergency drive source 26 is easily provided.

In the brake structure 11, when the driving force generated by the emergency driving source 26 is transmitted to the second switching chamber 55, the switching piston 53 closes the operation side flow path 31, and the operation pressure generated by the driving force is transmitted from the body side flow path 32 to the brake body portion 22. Therefore, it is not necessary to provide a structure for preventing the operation pressure generated by the driving force from flowing back to the operation pressure generation section 20 in the operation pressure circuit 30 .

According to the brake structure 11 of the present embodiment, the drive cylinder chamber 43 is partitioned by the drive piston 44 which is arranged in the drive cylinder 41 and which can move back and forth. The drive piston 44 is biased by the biasing portion 45 in the direction to decrease the volume of the drive cylinder chamber 43, and the electric portion 46 is configured to move and maintain the volume of the drive cylinder chamber 43 when power is supplied, and to allow the movement of the drive piston 44 in the direction to decrease the volume of the drive cylinder chamber 43 when power is lost. .

Therefore, when power is supplied, the driving piston 44 is moved by the electric portion 46 to increase the biasing force of the biasing portion 45, and the working fluid is sucked from the driving fluid pressure circuit 49 into the driving cylinder chamber 43, and this state is maintained. Moreover, because of the structure in which the biasing force is maintained by the electric portion 46, the fluid pressure in the drive cylinder chamber 43 is kept sufficiently low, and a structure for maintaining high fluid pressure working fluid for a long period of time is not required.

On the other hand, when power is lost, the driving piston 44 is moved by the biasing force of the biasing portion 45 to generate sufficient driving force and release it to the driving fluid pressure circuit 49 . Therefore, the emergency actuation unit 50 generates sufficient operation pressure from this driving force and transmits it through the operation pressure circuit 30, and the brake main unit 22 brakes the wheels 15, so that the emergency drive source 26 that generates sufficient operation pressure when power is lost is simply constructed.

The above embodiment can be changed as appropriate within the scope of the present invention.
Instead of the above embodiment using the poppet built-in switching valve 51 consisting of a piston valve as the emergency operation unit 50, a switching valve 51A without the poppet 58 shown in FIGS. 8 and 9 may be used as a modified example. In this switching valve 51A, similarly to the above-described embodiment, a switching piston 53 is arranged in a switching cylinder 52 so as to be able to advance and retreat, and a first switching chamber 54 and a second switching chamber 55 are provided, and the switching piston 53 is biased toward the second switching chamber 55 by a second compression spring 57.

Further, both the operation-side flow path 31 and the main-body-side flow path 32 open to the first switching chamber 54 and are provided so as to be connected in series through the first switching chamber 54, and the driving fluid pressure circuit 49 of the emergency drive source 26 is opened and connected to the second switching chamber 55. In this switching valve 51A, unlike the above-described embodiment, the operation-side flow path 31 is opened and connected to a position close to the switching piston 53 arranged at the bottom dead center in the first switching chamber 54 .

Even if this switching valve 51A is used, as in the above-described embodiment, in the normal energized state, in the emergency operation unit 50, as shown in FIG. Therefore, the operating pressure generated by the operating pressure generating section 20 is directly transmitted to the brake body section 22 from the operating side flow path 31 and the main body side flow path 32 to brake each wheel 15 .
On the other hand, in the event of an emergency such as a loss of electric power while the vehicle is running, pressurized working fluid is discharged from the fluid pressure device 25 of the emergency drive source 26 to the driving fluid pressure circuit 49, and this working fluid is supplied to the second switching chamber 55 to move the switching piston 53. Then, as shown in FIG. 9, the opening of the operation-side flow path 31 is closed by the switching piston 53, and the drive pressure from the emergency drive source 26 generates operation pressure, which is transmitted to the brake body 22 via the body-side flow path 32, and the vehicle stops running.

In the above embodiment, an example in which the operation pressure generation unit 20 is directly connected to the operation input unit 21 has been described, but any structure that can generate the working fluid pressure based on the operation of the brake pedal may be used. Further, it is not essential to provide a buffer 61 that communicates with the reservoir 60 and facilitates the supply and recovery of a sufficient amount of working fluid to the drive fluid pressure circuit 49, and the drive cylinder 41 without the detector 48 may be used.

Furthermore, the vehicle is not limited to a vehicle that runs unmanned by controlling devices used for running, turning, and stopping by the operation control unit 10, but may be a vehicle in which a driver rides and operates each device used for running, turning, and stopping.

10 Operation control unit 11 Brake structure 15 Wheel 16 Battery 20 Operation pressure generation unit 21 Operation input unit 22 Brake main unit 23 Operation auxiliary unit 24 Ignition switch (main switch)
25 Fluid pressure device 26 Emergency drive source 28 Drive source control unit 29 Hydraulic fluid tank 30 Operation pressure circuit 31 Operation side flow channel 32 Main body side flow channel 35 Booster 36 Master cylinder 37 Actuating portion 40 Emergency brake unit 41 Driving cylinder 43 Driving cylinder chamber 44 Driving piston 45 Biasing portion 46 Electric portion 47 Hollow portion 48 Detecting portion 49 Driving fluid pressure circuit 50 Emergency operating portion 51 Poppet Built-in switching valve 51A Switching valve modification 52 Switching cylinder 53 Switching piston 54 First switching chamber 55 Second switching chamber 56 First compression spring 57 Second compression spring 58 Poppet 60 Reservoir (oil tank)
61 buffer 62 supply channel 63 driving pressure channel 66 switching valve

Claims (3)

A brake structure for a vehicle, comprising: an operation pressure generation unit that generates an operation pressure based on a brake operation of an operation input unit; an operation pressure circuit that transmits the operation pressure by a first working fluid; a brake main unit that brakes a wheel by the operation pressure from the operation pressure circuit; and an operation control unit that controls braking of at least the wheel,
an emergency drive source that generates drive force when electric power is lost; and an emergency operation unit that generates the operation pressure in the first working fluid of the operation pressure circuit by the drive force and transmits the operation pressure to the brake main body ,
The emergency drive source is
a drive cylinder;
a drive piston disposed reciprocally within the drive cylinder and partitioning a drive cylinder chamber;
an urging portion that urges the drive piston in a direction to decrease the volume of the drive cylinder chamber;
a driving fluid pressure circuit that is connected between the driving cylinder chamber and the emergency operation unit and capable of supplying and discharging a second working fluid to and from the driving cylinder chamber;
an electric part that moves and maintains the drive piston in the direction of increasing the volume of the drive cylinder chamber when power is supplied, and allows the movement of the drive piston in the direction of decreasing the volume of the drive cylinder chamber when the power is lost,
The driving fluid pressure circuit is
a reservoir that stores the second working fluid;
a supply channel connected to the drive cylinder chamber so as to supply the second working fluid from the reservoir;
a driving pressure flow path that guides the second working fluid from the driving cylinder chamber to the emergency operating portion;
a switching valve that opens the supply channel when energized and closes the supply channel when not energized;
A brake structure for a vehicle, wherein the second working fluid discharged from the drive cylinder chamber is transmitted to the emergency operating portion through the drive pressure flow path by the switching valve blocking the supply flow path. The emergency operation unit has a switching cylinder, a switching piston arranged to be able to move back and forth in the switching cylinder, one switching chamber and the other switching chamber partitioned by the switching piston,
The operation pressure circuit has an operation-side flow path connected to the operation pressure generation section and a body-side flow path connected to the brake main body, and the operation-side flow path and the body-side flow path are connected in series via the one switching chamber,
2. The vehicle brake structure according to claim 1, wherein said emergency drive source is connected to said other switching chamber. 3. The vehicular brake structure according to claim 2, wherein when the driving force generated by the emergency drive source is transmitted to the other switching chamber, the switching piston closes the operation-side flow path and the operating pressure generated by the one switching chamber is transmitted to the brake main body via the main body-side flow path.

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