JP6605985B2 - Air supply system - Google Patents

Description

  The present invention relates to an air supply system that controls supply and discharge of air to a brake mechanism of a vehicle.

  The vehicle is provided with a pneumatic brake system including a service brake mechanism (foot brake mechanism) and a parking brake mechanism. The pneumatic brake system includes an air supply system that supplies compressed air from a compressor and supplies dried compressed air to each mechanism. Recently, an air supply system that includes an electronic control unit and is controlled by the electronic control unit has been proposed. (For example, refer to Patent Document 1).

JP 2007-326516 A

  However, in the above system, even in an emergency state such as a state where some abnormality occurs in a part of the air supply system, it is not considered until the service brake function is continuously maintained. For this reason, there is still room for improvement in the redundancy of the brake electronic control system.

  This invention is made | formed in view of such a situation, The objective is to provide the air supply system which can raise the redundancy of a brake electronic control system.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
An air supply system that solves the above problem is a main brake circuit that supplies air to and discharges air from a brake chamber that operates a service brake and is controlled by a main controller in the air supply system of a brake electronic control system. Connected to the brake chamber side, the air supply source side, and the discharge port side, and connected to the air supply source side and the brake chamber side, the brake chamber side and the discharge port A relay valve configured to be able to change the position to an exhaust position for connecting the main brake circuit and the brake chamber when the main brake circuit is operating, and the relay valve and the brake chamber when the main brake circuit is not operating The switching part for connecting the brake chamber and the position of the relay valve And a control unit for controlling.

  According to the above configuration, when the main brake circuit is not in operation, the relay valve and the brake chamber are connected by the switching unit, and the air is supplied to the brake chamber and the air is supplied via the relay valve whose position is controlled by the control device. It can be discharged. Therefore, even in an emergency state such as when an abnormality occurs in the main brake circuit, the service brake can be operated by operating the air supply system via a relay valve instead of the main brake circuit. Therefore, the redundancy of the brake electronic control system can be increased.

  In the air supply system, a first control valve that is in a connected position when energized by the control device and is in a shut-off position when de-energized, a shut-off position when energized by the control device, is in a connected position when de-energized, A second control valve disposed closer to the discharge port than one control valve, and a signal path of the relay valve is connected between the first control valve and the second control valve, and the relay valve Is the exhaust position when the first control valve and the second control valve are not energized, and the supply position when the first control valve and the second control valve are energized.

According to the above configuration, the position of the relay valve is changed by energizing and de-energizing the first control valve and the second control valve. For this reason, a high-pressure channel can be opened and closed with a simple configuration.
The air supply system includes a pressure sensor that detects a pressure of a flow path connecting the switching unit and the brake chamber, and the control device inputs a signal corresponding to a vehicle speed from a vehicle speed detection unit, and the pressure sensor The relationship between the detected pressure and the vehicle speed is learned, and when the main brake circuit is not operating, the pressure in the brake chamber is controlled based on the required deceleration value and the learning result.

  According to the above configuration, even when the main brake circuit operates and the air supply system does not operate, the relationship between the pressure in the brake chamber and the acceleration / deceleration of the vehicle is learned in advance. Thereby, when the air supply system operates in an emergency, the pressure of the brake chamber can be adjusted to an appropriate pressure according to the required value of acceleration / deceleration.

In the air supply system, the air supply source connected to the relay valve is different from the air supply source of the main brake circuit.
According to the above configuration, since the air supply source connected to the relay valve is different from the air supply source of the main brake circuit, the brake is activated and released even when an abnormality such as air leakage occurs in the latter air supply source. can do.

  The air supply system is an air supply system that is mounted on a vehicle that forms a formation with other vehicles and travels unattended, and communicates with a brake chamber side, an air supply source side, and a discharge port side that operate a service brake. A connection position for connecting the air supply source side and the brake chamber side, a relay valve configured to change the position to an exhaust position for connecting the brake chamber side and the discharge port, and a connection position when energized, A first control valve that becomes a shut-off position when not energized, a second control valve that becomes a shut-off position when energized, becomes a connection position when not energized, and is disposed closer to the discharge port than the first control valve; And a control device that controls the first control valve and the second control valve.

  According to the said structure, supply of the air to a brake chamber and discharge | emission of air can be performed via a relay valve by control of a 1st control valve and a 2nd control valve by a control apparatus. Therefore, the service brake can be operated and released even in the emergency state of the main brake circuit during unmanned travel.

  According to the present invention, the redundancy of the brake electronic control system can be increased.

The figure which shows schematic structure of the brake system of 1st Embodiment. The circuit diagram which shows schematic structure of the security module which comprises the brake system of the embodiment. The circuit diagram which shows operation | movement of the normal driving mode of the security module in the embodiment. The circuit diagram which shows operation | movement of the operation mode of the security module in the embodiment. The circuit diagram which shows the operation | movement of the cancellation | release mode of the security module in the embodiment. The schematic diagram of the vehicle to which the brake system of 2nd Embodiment is applied. The figure which shows schematic structure of the module of the embodiment. The circuit diagram which shows schematic structure of the security module of other embodiment.

(First embodiment)
Hereinafter, a first embodiment in which an air supply system is applied to a brake system for a connected vehicle will be described with reference to FIGS. The brake system includes a parking brake and a service brake as brakes using compressed dry air as a drive source. The connected vehicle is a vehicle in which a trailer is connected to a tractor.

  As shown in FIG. 1, the vehicle includes a main module 11 as a main brake circuit and a security module 12 as an air supply system as a tractor brake system. The main module 11 is provided for each tractor wheel. A security module 12 is also provided for each wheel of the tractor. In FIG. 1, the main module 11 and the security module 12 provided for one of the four wheels of the tractor are illustrated, and the main module 11 and the security module 12 provided for the other wheels are illustrated. Is omitted.

  The main module 11 is a brake module that operates during normal travel, and the security module 12 is a module that operates in an emergency state where the main module 11 cannot be used. The emergency state includes a state in which an abnormality has occurred in a part of the main module 11, a state in which an abnormality has occurred in the driver, and a driving operation has become impossible.

  The main module 11 has an input port 13 connected to the brake air tank 15 and an output port 14 connected to the spring brake chamber 50 via the chamber connection path 16. A filter 17 that dries air is provided between the brake air tank 15 and the main module 11.

  The spring brake chamber 50 is provided on the rear wheel of the tractor. The spring brake chamber 50 includes a first control chamber 51 that controls a service brake and a second control chamber 52 that controls a parking brake. The air stored in the brake air tank 15 is supplied to the first control chamber 51 by an amount corresponding to the operation amount of the brake pedal of the driver. When air is supplied to the first control chamber 51, the push rod 54 moves to the wheel side by the air pressure in the first control chamber 51. When the wedge 53 provided at the tip of the push rod 54 spreads the brake lining provided on the wheel, the service brake is activated by friction between the brake shoe and the brake lining. When air is discharged from the first control chamber 51, the wedge 53 is withdrawn from the brake lining and the service brake is released. Further, when air is supplied to the second control chamber 52, the spring 55 extends to move the push rod 54 to the wheel side. When the wedge 53 pushes the brake lining provided on the wheel by the urging force of the spring 55, the parking brake is activated. Further, when air is discharged from the second control chamber 52, the wedge 53 is withdrawn from the brake lining and the parking brake is released.

  The output port 14 of the main module 11 is connected to the first control chamber 51 of the spring brake chamber 50. The front wheel of the tractor is provided with a service brake chamber including a first control chamber 51, a push rod 54, and a wedge 53. The service brake chamber operates and releases only the service brake, and does not operate and release the parking brake. The security module 12 connected to the service brake chamber is connected to the first control room 51 of the service brake chamber.

  The security module 12 is provided in parallel to the main module 11. The input port 20 of the security module 12 is connected to a suspension air tank 22 provided in a vehicle air suspension (suspension device). A filter 17 is provided between the suspension air tank 22 and the input port 20. The output port 21 of the security module 12 is connected to the spring brake chamber 50 or the first control chamber 51 of the service brake chamber via the chamber connection path 16. Since the security module 12 is provided in parallel with the main module 11, it is possible to prevent adverse effects on the operation of the main module 11.

  The main module 11 includes a first ECU (Electronic Control Unit) 18 as a main control device and a control valve controlled by the first ECU 18. The security module 12 includes a second ECU 25 as a control device and a control valve controlled by the second ECU 25. The first ECU 18 and the second ECU 25 are connected to an in-vehicle network 60 such as a CAN (Controller Area Network) and configured to transmit and receive various types of information. The in-vehicle network 60 is connected to a master ECU 61 that controls the processing of the first ECU 18 and the second ECU 25. The master ECU 61 transmits commands to the first ECU 18 and the second ECU 25, and the first ECU 18 and the second ECU 25 execute various processes based on the commands.

  When the master ECU 61 detects an abnormality of the driver, the master ECU 61 recognizes the driver's face and determines whether the driver is asleep or conscious, or a device that detects the driver's pulse and respiratory rate. A detection signal is input from the above to determine whether or not the driver is in an abnormal state.

  Next, a schematic configuration of the security module 12 connected to the spring brake chamber 50 will be described with reference to FIG. FIG. 2 shows circuits 12A and 12B of a pair of security modules 12 provided for a pair of wheels provided on one axle. Each security module 12 shares one second ECU 25.

  The first flow path 31 connected to the suspension air tank 22 is connected to a second flow path 32 that distributes air to the pair of security modules 12. A third flow path 33 is connected between the second flow path 32 and the chamber connection path 16. A relay valve 40 is connected in the middle of the third flow path 33.

  The relay valve 40 is a 3-port 2-position valve connected to the second flow path 32, the third flow path 33, and the fifth flow path 35, and is driven by air pressure. The relay valve 40 is in a supply position when an air pressure signal is input to the signal input port 41, and is exhausted when no air pressure signal is input to the signal input port 41, that is, when the signal input port 41 is not filled with air. Position. The relay valve 40 communicates the second flow path 32 and the third flow path 33 at the supply position. That is, the air supplied from the suspension air tank 22 is supplied to the spring brake chamber 50 via the third flow path 33. At the exhaust position, the fifth flow path 35 and the third flow path 33 are communicated. The fifth flow path 35 connects one relay valve 40 at the exhaust position and the relay valve 40 at the other exhaust position to the discharge port 39 side. At this position, the air filled in the spring brake chamber 50 is discharged from the discharge port 39 through the chamber connection path 16, the third flow path 33, the fifth flow path 35, and the like.

  A switching unit 42 is provided between the third flow path 33 and the chamber connection path 16. The switching unit 42 is connected to the main side port P <b> 1 on the main module 11 side, the third flow path 33, and the chamber connection path 16. The switching unit 42 includes a double check valve. The switching unit 42 allows the air flow from the high pressure side to the spring brake chamber 50 out of the pressure on the main module 11 side and the pressure on the third flow path 33 side, and blocks the low pressure side. When the main module 11 is not operating due to an abnormality occurring in the main module 11, air is not supplied to the main side port P1 from the main module 11 side, so the main side port P1 and the spring brake chamber 50 are not connected. The air flow between them is interrupted.

  In the middle of the chamber connection path 16, a pressure sensor 43 that detects the pressure in the chamber connection path 16 is provided. The pressure sensor 43 outputs a signal corresponding to the pressure inside the chamber connection path 16 to the second ECU 25.

  One end of the fourth flow path 34 is connected to the second flow path 32. The other end of the fourth flow path 34 is connected to the discharge port 39 side. A first control valve 45 and a second control valve 46 controlled by the second ECU 25 are provided in the middle of the fourth flow path 34. The first control valve 45 is provided on the upstream side, which is the second flow path 32 side, with respect to the second control valve 46.

  The first control valve 45 is a normally closed electromagnetic valve, and has a shut-off position that is a non-energized position and a connection position that is a energized position. The second control valve 46 is a normally open solenoid valve, and has a connection position that is a non-energized position and a cutoff position that is a energized position. A signal path 38 connected to the signal input port 41 of the relay valve 40 is connected to the flow path between the first control valve 45 and the second control valve 46. The air filling state of the signal path 38 is controlled by the combination of the position of the first control valve 45 and the position of the second control valve 46. Thereby, the flow path through which high-pressure air flows with a small amount of electric power can be opened and closed. Since the solenoid valve is only the first control valve 45 and the second control valve 46 and the relay valve 40 is controlled by these, the number of parts of the security module 12 can be reduced.

  Next, the operation of the security module 12 will be described with reference to FIGS. The safety module 12 releases the brake when the main module 11 is operating, the normal driving mode when the main module 11 is operating, the operation mode when the main module 11 is not operating and the brake is activated, and the main module 11 is not operating. Has release mode. 3 to 5, a thick solid line indicates a state in which the flow path is filled with compressed air.

First, the normal travel mode of the security module 12 will be described with reference to FIG.
As shown in FIG. 3, while the main module 11 is operating normally, the first control valve 45 is in the shut-off position and shuts off the supply of air from the suspension air tank 22. The second control valve 46 is in the connection position, and the air in the fourth flow path 34 is discharged from the discharge port 39. Since the signal input port 41 of the relay valve 40 is not filled with air, the air is discharged from the discharge port 39 via the fifth flow path 35. Thereby, the security module 12 is not involved in the supply and discharge of air to the spring brake chamber 50.

  Further, while the main module 11 is operating normally, the main side port P <b> 1 becomes high pressure, and the air flow between the spring brake chamber 50 and the security module 12 is blocked by the switching unit 42. The pressure sensor 43 detects the pressure in the chamber connection path 16 and outputs a signal corresponding to the pressure to the second ECU 25. The second ECU 25 inputs a signal corresponding to the vehicle speed from the vehicle speed sensor 62 via the in-vehicle network 60. The second ECU 25 calculates an actual deceleration (hereinafter referred to as an actual deceleration) based on the vehicle speed. The second ECU 25 learns by recording the relationship between the actual deceleration and the pressure in the chamber connection path 16 in the storage unit. Further, when the second ECU 25 operates the safety module 12, the second ECU 25 inputs a deceleration request value that is a deceleration requested from the master ECU 61, and learning information indicating the relationship between the actual deceleration and the pressure in the chamber connection path 16. Read from the storage unit. Then, the second ECU 25 controls the pressure in the chamber connection path 16 so that the actual deceleration approaches the deceleration request value based on the read learning information. Although the actual deceleration is calculated based on the vehicle speed input from the vehicle speed sensor 62 here, acceleration may be input from the acceleration sensor. Note that when the acceleration is a negative value, deceleration occurs. Further, the second ECU 25 may control the pressure in the chamber connection path 16 so that the actual jerk (jerk, jerk) approaches the instructed jerk. The jerk can be calculated using an acceleration sensor or a vehicle speed sensor 62. The acceleration sensor and the vehicle speed sensor 62 correspond to a vehicle speed detection unit.

  When the master ECU 61 or the first ECU 18 of the main module 11 fails, a failure signal is input to the second ECU 25 of the security module 12 via the in-vehicle network 60. Further, the second ECU 25 inputs a vehicle speed signal from a vehicle speed sensor 62 that detects the rotational speed of the wheel via the in-vehicle network 60. When a failure signal is input, it is determined whether emergency braking is possible based on the vehicle speed obtained from the vehicle speed signal. For example, when the emergency braking start condition is satisfied, for example, the vehicle speed becomes a predetermined value or more while the failure signal is being input, the second ECU 25 shifts the safety module 12 to the operation mode. Alternatively, the second ECU 25 shifts the safety module 12 to the operation mode when a deceleration instruction braking start condition is satisfied, for example, when a deceleration instruction is input from the master ECU 61 while a failure signal is input. This deceleration instruction is, for example, that the driver's brake pedal has been operated, or that the relative distance from the obstacle has become a lower limit value or less, and the master ECU 61 determines whether output is possible.

Next, the operation mode of the security module 12 will be described with reference to FIG.
As shown in FIG. 4, the master ECU 61 stops the operation of the main module 11 when the emergency braking start condition or the braking start condition based on the deceleration instruction is satisfied. When the operation of the main module 11 stops, the switching unit 42 blocks the main port P1 side.

  The second ECU 25 energizes the first control valve 45 and the second control valve 46 of each safety module 12 when receiving a command to start the brake operation from the master ECU 61. The first control valve 45 is in the connection position, and the second control valve 46 is in the cutoff position. As a result, the first flow path 31, the second flow path 32, a part of the fourth flow path 34, and the signal path 38 are filled with air, and the relay valve 40 is disposed at the connection position. Therefore, the air supplied from the suspension air tank 22 is supplied to the first control chamber 51 of the spring brake chamber 50 via the second flow path 32, the relay valve 40, and the switching unit 42. This activates the service brake. Further, the second ECU 25 acquires the required deceleration value from the master ECU 61, calculates the required pressure based on the learning result, and controls the first control valve 45 and the second control valve 46 so as to obtain the pressure. To do. When the second ECU 25 determines that the pressure is excessive, the first control valve 45 and the second control valve 46 are de-energized. When the second ECU 25 determines that the pressure is excessive, the first control valve 45 and The second control valve 46 is energized. The second ECU 25 may adjust the pressure by opening and closing the first control valve 45 and the second control valve 46 by performing control for inputting a high-frequency signal and PWM (Pulse Width Modulation). it can.

Next, the release mode of the security module 12 will be described with reference to FIG. In FIG. 5, a thick broken line indicates a state where air is discharged.
As shown in FIG. 5, the second ECU 25 deenergizes the first control valve 45 and the second control valve 46 of each safety module 12 when a command to start releasing the brake is input from the master ECU 61. . The first control valve 45 is in the cutoff position, and the second control valve 46 is in the connection position. Thereby, the air in the fourth flow path 34 is discharged from the discharge port 39. The air in the signal path 38 is exhausted through the fourth flow path 34, and the relay valve 40 becomes the exhaust position. The air in the first control chamber 51 of the spring brake chamber 50 is discharged from the discharge port 39 via the chamber connection path 16 and the third flow path 33. As a result, the service brake is released.

  On the other hand, if an abnormality has occurred in the second ECU 25 or an abnormality has occurred in a part of the security module 12, the first control valve 45 and the second control valve 46 are in a non-energized state. As a result, the service brake is released. Since the service brake and the parking brake do not operate simultaneously, the parking brake can be operated separately by releasing the service brake.

As described above, according to the present embodiment, the following effects can be obtained.
(1) When the main module 11 is not operating, the relay valve 40 and the spring brake chamber 50 (or service brake chamber) are connected by the switching unit 42, and the spring brake is connected via the relay valve 40 whose position is controlled by the second ECU 25. Air can be supplied to and discharged from the chamber 50. Therefore, even in an emergency state such as when an abnormality occurs in the main module 11, the service brake can be activated by operating the security module 12 instead of the main module 11. Therefore, the redundancy of the brake electronic control system can be increased.

(2) The position of the relay valve 40 is changed by energizing and de-energizing the first control valve 45 and the second control valve 46. For this reason, a high-pressure channel can be opened and closed with a simple configuration.
(3) The relationship between the pressure in the spring brake chamber 50 and the vehicle speed is learned in advance even when the main module 11 is operating and the safety module 12 is not operating. Thereby, when the safety module 12 operates in an emergency, the pressure of the spring brake chamber 50 can be adjusted to an appropriate pressure according to the required value.

  (4) The safety module 12 uses the suspension air tank 22 as an air supply source, and the main module 11 uses the brake air tank 15 as an air supply source. For this reason, for example, even when an abnormality such as air leakage occurs in the brake air tank 15, the brake can be operated and released.

(Second Embodiment)
Next, with reference to FIG. 6 and FIG. 7, a second embodiment in which the air supply system is embodied as a system for an unmanned driving vehicle provided in a vehicle traveling in a platoon will be described. The description will focus on the differences from the first embodiment. The basic structure of the air supply system according to this embodiment is the same as that of the first embodiment, and in the drawings, substantially the same elements as those of the first embodiment are denoted by the same reference numerals. , I will omit the duplicate explanation.

  As shown in FIG. 6, the platooning is traveling by a platoon formed by a leading vehicle 100 that is operated by a driver and an unmanned subsequent vehicle 101. The leading vehicle 100 and the following vehicle 101 are connected vehicles. The master ECU 61 of the leading vehicle 100 and the master ECU 61 of the following vehicle 101 travel while transmitting and receiving various information by wireless communication and maintaining a certain inter-vehicle distance. Wireless communication may be performed between vehicles arranged in the front and rear in the formation, or wireless communication may be performed between the leading vehicle 100 and each subsequent vehicle 101. FIG. 6 shows an example in which vehicles arranged in front and rear, the last succeeding vehicle 101 and the leading vehicle 100 perform wireless communication.

  The manned leading vehicle 100 activates the brake based on the driver's braking operation, and the unmanned following vehicle 101 activates the brake following the immediately preceding vehicle. For this reason, the succeeding vehicle 101 needs an automatic brake circuit that can automatically operate and release the brake based on a command from the master ECU 61. However, a technique related to such an automatic brake has not yet been established. Therefore, in the present embodiment, the safety module 12 is used as an automatic brake circuit that operates even during normal times. In FIG. 6, a row is formed by three connected vehicles, but a plurality of vehicles may be used.

  As shown in FIG. 7, the security module 12 is configured such that the switching unit 42 is omitted, and the relay valve 40 and the spring brake chamber 50 are connected. The ECU 25A corresponding to the second ECU of the first embodiment energizes the first control valve 45 and the second control valve 46 when operating the service brake and releases the first control valve when releasing the service brake. 45 and the second control valve 46 are deenergized.

As described above, according to the present embodiment, the following effects can be obtained.
(5) In the following vehicle 101 in unmanned operation, the ECU 25A can supply air to the spring brake chamber 50 and discharge air through the relay valve 40. Therefore, even in unmanned operation, the service brake can be activated by operating the security module 12 instead of the main module 11.

(Other embodiments)
In addition, each said embodiment can also be implemented with the following forms.
As shown in FIG. 8, the switching unit 42 may be a switching unit 42 </ b> A composed of a valve that opens and closes by an air pressure signal. The switching unit 42A serves as a connection position for connecting the chamber connection path 16 and the third flow path 33 when no air pressure signal is input to the signal input port 42B. The switching unit 42 </ b> A is a blocking position that blocks the chamber connection path 16 and the third flow path 33 when an air pressure signal is input to the signal input port 42 </ b> B.

The pair of security modules 12 share the second ECU 25, but the security modules 12 may each include the second ECU 25.
In each of the above embodiments, the air supply source of the safety module 12 is the suspension air tank 22, and the air supply source of the main module 11 is the brake air tank 15. However, the air supply source of the security module 12 and the air supply source of the main module 11 may be the same.

  In each of the above embodiments, the second ECU 25 controls the security module 12 based on the learning result. However, the second ECU 25 may control the security module 12 based on a preset value or the like without using the learning result. In this way, the calculation load on the second ECU 25 can be reduced.

  In each of the above embodiments, the circuit 12A of one wheel and the circuit 12B of the other wheel of the same axle are connected via the second flow path 32. However, the circuits 12A and 12B may be independent of each other. If it does in this way, the brake force for every wheel can be controlled by controlling the pressure of each circuit 12A and 12B separately.

  In each of the above embodiments, the air supply system has been described as being mounted on a connected vehicle that includes a tractor and a trailer. As another aspect, the air supply system may be mounted on other vehicles such as a bus, a truck in which a cargo bed is integrated, a passenger car, and a railway vehicle.

  DESCRIPTION OF SYMBOLS 11 ... Main module, 12 ... Security module, 12A, 12B ... Circuit, 13 ... Input port, 14 ... Output port, 15 ... Brake air tank, 16 ... Chamber connection path, 17 ... Filter, 20 ... Input port, 21 ... Output Port, 22 ... Air tank for suspension, 18 ... 1ECU, 25 ... 2ECU, 61 ... Master ECU, 31-35 ... 1st flow path-5th flow path, 38 ... Signal path, 39 ... Discharge port, 40 ... Relay Valve, 41 ... Signal input port, 42, 42A ... Switching unit, 42B ... Signal input port, 43 ... Pressure sensor, 45 ... First control valve, 46 ... Second control valve, 50 ... Spring brake chamber, 51 ... First Control room 52 ... Second control room 53 ... Wedge 54 ... Push rod 55 ... Spring 60 ... In-vehicle network 62 ... Vehicle speed sensor 10 ... the leading vehicle, 101 ... following vehicle, P1 ... the main-side port.

Claims (5)

In the air supply system of the brake electronic control system,
Air is supplied to and discharged from the brake chamber that operates the service brake, and is provided in parallel to the main brake circuit controlled by the main control device,
The brake chamber side, the air supply source side, and the discharge port side communicate with each other, and the air supply source side and the brake chamber side are connected to each other, and the brake chamber side and the exhaust port that connects the discharge port are located. A relay valve configured to be changeable,
A switching unit for connecting the main brake circuit and the brake chamber when the main brake circuit is in operation, and for connecting the relay valve and the brake chamber when the main brake circuit is not operating;
And a control device for controlling the position of the relay valve. A first control valve that is in a connected position when energized by the control device and is in a shut-off position when de-energized;
A second control valve that is located at a shut-off position when energized by the control device, is connected to a non-energized position, and is disposed closer to the discharge port than the first control valve;
The signal path of the relay valve is connected between the first control valve and the second control valve,
The relay valve is in the exhaust position when the first control valve and the second control valve are not energized, and is in the connection position when the first control valve and the second control valve are energized. Air supply system. A pressure sensor for detecting a pressure of a flow path connecting the switching unit and the brake chamber;
The control device receives a signal corresponding to the vehicle speed from the vehicle speed detection unit, learns the relationship between the pressure detected by the pressure sensor and the vehicle speed, and when the main brake circuit is not operating, a required deceleration value The air supply system according to claim 1, wherein the pressure of the brake chamber is controlled based on the learning result. The air supply system according to any one of claims 1 to 3, wherein the air supply source connected to the relay valve is different from an air supply source of the main brake circuit. An air supply system mounted on a vehicle that forms a platoon with other vehicles and travels unattended,
Connected to the brake chamber side, the air supply source side, and the discharge port side for operating the service brake, the connection position connecting the air supply source side and the brake chamber side, and the exhaust connecting the brake chamber side and the discharge port A relay valve configured to be able to change position to position,
A first control valve that is in a connected position when energized and in a shut-off position when de-energized
A second control valve that is located at a shut-off position when energized, is a connected position when non-energized, and is disposed closer to the outlet than the first control valve;
A control device for controlling the first control valve and the second control valve;
With an air supply system.