JP6796495B2 - Pneumatic braking system - Google Patents

Description

The present invention relates to a pneumatic braking system that operates a brake using compressed air.

In recent years, research and development of a system for realizing platooning in which a plurality of vehicles form a platoon is being promoted. Each vehicle forming a platoon communicates with each other and travels so as to maintain a predetermined inter-vehicle distance. In particular, in the field of logistics, a system for platooning by a leading vehicle driven by a driver and a following vehicle driven by an unmanned or observer has been proposed. In the following vehicle, vehicle control is performed according to the behavior of the leading vehicle. For example, in brake control, when the leading vehicle activates the brake, the following vehicle follows and activates the brake. Freight vehicles such as trucks used in this field are equipped with a pneumatic braking system that operates brakes using compressed air.

By the way, since the following vehicle is unmanned driving or automatic driving in which the vehicle behavior is monitored by a monitor, it cannot be expected that the driver will operate the vehicle when an abnormality occurs in the pneumatic braking system. Therefore, the pneumatic braking system of a vehicle traveling in a platoon is required to have safety so as to be able to cope with an abnormality of the pneumatic braking system. For example, Patent Document 1 proposes a platooning control system in which a braking system is multiplexed. The system includes a regular brake actuator, an emergency brake actuator, and a safety brake actuator. The regular brake actuator is a device for driving the regular brake. The emergency brake actuator is used in the event of a failure of the regular brake actuator, or is used together with the regular brake actuator when the vehicle is stopped in an emergency. The safety brake actuator is provided as an actuator of a system different from the normal brake actuator and the emergency brake actuator, and is a device for driving the safety brake when the normal brake actuator and the emergency brake actuator fail.

JP-A-2007-233965

However, in the above system, it is not assumed how the emergency brake actuator or the like is mounted on the vehicle.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pneumatic braking system capable of further enhancing the safety of the pneumatic braking system.

A pneumatic brake system that solves the above problems is a pneumatic brake system that supplies and discharges air from an air supply source to a brake mechanism that operates and releases a vehicle service brake, and is normally controlled by a first brake control device. A plurality of safety modules are provided, which are controlled by a second brake control device to supply and discharge air to the brake mechanism when the module to be operated does not operate.

According to the above configuration, the pneumatic brake system includes a plurality of safety modules that operate when the module controlled by the first brake control device does not operate. Therefore, as compared with the case where there is only one security module, even if an abnormality occurs in at least one of the security modules, the brake is applied by the other security module, so that the safety of the pneumatic braking system can be further improved.

The pneumatic brake system includes an air supply unit that distributes the air supplied from the air supply source as an air pressure signal in a supply system different from the air supply source and the supply system including the module. Is preferable.

According to the above configuration, the air supply unit can distribute air to a plurality of safety modules in a supply system different from the module controlled by the first brake control device. Therefore, even if there is an abnormality in the supply system including the module, the brake can be forcibly operated.

It is preferable that the safety module is provided for each wheel of the pneumatic braking system, and one air supply unit is connected to each of the safety modules.
According to the above configuration, one air supply unit is provided for the plurality of security modules. Therefore, the number of parts can be reduced as compared with the case where an air supply unit for supplying an air pressure signal is provided for each safety module.

Regarding the pneumatic braking system, the air supply unit has an electromagnetic control valve that supplies air supplied from the air supply source as an air pressure signal, and the air to the plurality of safety modules depending on the presence or absence of the air pressure signal. It is preferable to include a first relay valve that distributes the air stored in the supply source.

Since the air supply unit distributes air as an air pressure signal to the plurality of safety modules, it is necessary to supply a large amount of air. According to the above configuration, the air supply unit includes a relay valve that is controlled by a small amount of air, which is an air pressure signal, and supplies a larger amount of air than the air pressure signal. Therefore, a large amount of air stored in the air supply source can be distributed to a plurality of security modules in a short time.

Regarding the pneumatic braking system, it is preferable that the electromagnetic control valve supplies the air supplied from the air supply source to the first relay valve when the power is not supplied.
According to the above configuration, the electromagnetic control valve outputs an air pressure signal to the first relay valve when it is not energized. Therefore, when an abnormality occurs in the control device that controls the electromagnetic control valve, the air pressure is adjusted to operate the service brake. The signal can be output to the first relay valve. Therefore, the safety of the pneumatic braking system can be improved.

Regarding the pneumatic brake system, the air supply unit includes an air pressure control valve that inputs air as an air pressure signal from the brake mechanism side when the parking brake is released, and the air pressure control valve inputs the air pressure signal. It is preferable that the connection position is for supplying air to the first relay valve, and the position is for stopping the supply of air to the first relay valve when the air pressure signal is not input.

According to the above configuration, the air pressure control valve supplies air to the first relay valve when the parking brake is released. Therefore, only when the parking brake is released, the air pressure control valve and the first relay valve Air can be supplied to the brake mechanism side and the service brake for safety can be activated.

With respect to the pneumatic brake system, the safety module has a higher pressure than the safety electromagnetic control valve controlled by the second brake control device, the first relay valve side, and the safety electromagnetic control valve side. A shuttle valve that allows the flow of air from the side, and a second that supplies the air stored in the air supply source to the brake mechanism side when the air supplied from the shuttle valve side is input as an air pressure signal. It is preferable to provide a relay valve.

According to the above configuration, the second relay valve can supply a large amount of air stored in the air supply source to the brake mechanism side when a small amount of air, which is an air pressure signal, is supplied. Therefore, it is possible to shorten the operating time from when the output of the pneumatic signal to the second relay valve is started until the service brake is activated. Further, the air pressure signal can be supplied to the second relay valve from the forced brake connection path and the safety electromagnetic control valve, whichever has the higher pressure, via the shuttle valve. That is, since the second relay valve can be shared by both the system that supplies air from the air supply unit to the brake mechanism and the system that supplies air from the safety electromagnetic control valve to the brake mechanism, the number of parts can be reduced. Can be done.

According to the present invention, the safety of the pneumatic braking system can be further enhanced.

For one embodiment of the pneumatic braking system, a schematic diagram of each vehicle in which the pneumatic braking system is mounted and which forms a platoon. The schematic diagram which shows the connection state of the ECU of the pneumatic brake system of the same embodiment. The schematic diagram which shows the whole structure of the pneumatic brake system of the same embodiment. It is a pneumatic circuit which shows a part of the pneumatic brake system of the same embodiment in detail, and is the circuit diagram which shows the state which the parking brake is activated. The circuit diagram which is the pneumatic circuit of the pneumatic brake system of the same embodiment, and shows the state which decelerated in the deceleration running mode. The circuit diagram which shows the state which is the pneumatic circuit of the pneumatic brake system of the same embodiment, and is not decelerating in the deceleration running mode. The circuit diagram which is the pneumatic circuit of the pneumatic brake system of the same embodiment, and shows the state of the forced brake mode. The circuit diagram which is the pneumatic circuit of the pneumatic brake system of the same embodiment, and shows the state of the re-running mode. The circuit diagram which shows the state which performs the manned operation in the re-running mode which is the pneumatic circuit of the pneumatic brake system of the same embodiment.

Hereinafter, an embodiment in which the pneumatic braking system is applied to a vehicle traveling in a platoon will be described.
The platooning will be described with reference to FIG. Here, the vehicle 100 forming a platoon is a freight vehicle, which is a truck integrally provided with a loading platform. The platoon is formed when traveling in a predetermined section, and is composed of a leading vehicle 100a and a following vehicle 100b traveling behind the leading vehicle 100a. The leading vehicle 100a is driven by the driver (manned driving). The following vehicle 100b is either unmanned and automatically driven (unmanned driving), or is automatically driven by an observer. The observer only monitors the behavior of the vehicle and basically does not drive. The vehicle 100 forming a platoon transmits information such as speed to the vehicle 100 traveling behind the vehicle 100, for example, every several milliseconds to several tens of milliseconds. The vehicle 100 accelerates or decelerates so that the distance between the vehicle and the vehicle 100 in front becomes a predetermined distance based on the received information such as the speed. In addition, the following vehicle 100b may be driven by the driver as necessary, such as when traveling on a road other than a predetermined section in which the platooning is performed. In addition, although the formation was formed by three vehicles 100 in FIG. 1, the number of vehicles forming the formation may be a plurality of vehicles other than three.

The configuration of the platooning control system 10 of the vehicle 100 will be described with reference to FIGS. 2 and 3. It is assumed that the leading vehicle 100a and the following vehicle 100b are equipped with the same platooning control system 10.

As shown in FIG. 2, the platooning control system 10 includes a platooning ECU (electronic control unit) 11 that performs various controls for platooning. The platooning ECU 11 is duplicated by the first platooning ECU 11A and the second platooning ECU 11B. For example, even if an abnormality occurs in the first platoon traveling ECU 11A, the second platoon traveling ECU 11B controls the vehicle 100. When the first platoon traveling ECU 11A and the second platoon traveling ECU 11B are described without distinction, they are simply described as the platoon traveling ECU 11.

In addition, the platooning control system 10 includes a first brake ECU 15A as a first brake control device and a second brake ECU 15B as a second brake control device. The first brake ECU 15A is an ECU having a higher priority than the second brake ECU 15B, and controls the pneumatic brake system in a normal time when there is no abnormality in itself to operate and release the brake. The pneumatic brake system operates a service brake (regular brake, foot brake) in which the braking force is variable by air pressure, and a parking brake (parking brake) in which a predetermined braking force is applied to the wheels by the urging force of the spring.

The second brake ECU 15B controls the safety module included in the pneumatic brake system in an emergency such as when an abnormality occurs in the first brake ECU 15A. In an emergency, when an abnormality occurs in both the first platoon traveling ECU 11A and the second platoon traveling ECU 11B other than when an abnormality occurs in the first brake ECU 15A, the first brake ECU 15A and the first platoon traveling ECU 11A And when an abnormality occurs in all of the second platooning ECU 11B.

The first platoon traveling ECU 11A, the second platoon traveling ECU 11B, the first brake ECU 15A, and the second brake ECU 15B are connected to the vehicle-mounted network 19. The in-vehicle network is, for example, a network such as CAN (Controller Area Network), FlexRay (registered trademark), and Ethernet (registered trademark). The first brake ECU 15A and the second brake ECU 15B control the actuator based on the deceleration instruction from the first platoon traveling ECU 11A or the second platoon traveling ECU 11B. Further, a vehicle speed sensor 58 is connected to the vehicle-mounted network 19. The vehicle speed sensor 58 transmits the speed to the vehicle-mounted network 19 at a predetermined timing. A communication control unit (not shown) for detecting a communication error or the like is connected to the in-vehicle network 19. Each ECU connected to the vehicle-mounted network 19 sends a predetermined communication message to the vehicle-mounted network 19 with its own ID, and acquires the communication message to be acquired from the vehicle-mounted network 19.

Next, the overall configuration of the pneumatic brake system 20 will be described with reference to FIG. The pneumatic brake system 20 supplies the air stored in the air storage tank 21 and other tanks to the brake chamber 50 as a brake mechanism. The brake chamber 50 is provided for each wheel. In FIG. 3, only a pair of front wheels 51 and a pair of rear wheels 52, which are driving wheels, are shown, but the number of front wheels 51 and the number of rear wheels 52 are not particularly limited. For example, the vehicle 100 may be provided with a pair of front wheels 51 and two pairs of rear wheels 52. In FIG. 3, the solid line connecting the tank and the actuator shows the air passage, and the broken line shows the state where the ECU and the actuator are electrically connected.

The air storage tank 21, which is an air supply source, stores air compressed by the compressor 22 and dried by the air dryer 23 having a desiccant. The air storage tank 21 is connected to the protection valve (protection valve) 24 via a pipeline. The protection valve 24 distributes the air supplied from the air storage tank 21 to the parking brake tank 25, the rear wheel brake tank 26, and the front wheel brake tank 27.

The front wheel brake tank 27 is connected to the axle modulator 30 via a brake valve 31. The brake valve 31 includes a front wheel control unit 31A connected to the front wheel brake tank 27 and a rear wheel control unit 31B connected to the rear wheel brake tank 26. The front wheel control unit 31A is connected to the front wheel axle modulator 30. Further, the brake valve 31 supplies air from the front wheel control unit 31A to the axle modulator 30 under the control of the first brake ECU 15A. The axle modulator 30 controls the supply and discharge of air to the brake chamber 50 provided in the front wheel 51.

The first brake ECU 15A inputs a position detection signal from a sensor that detects the position of a brake pedal (not shown) operated by the driver when the vehicle 100 is driven by the driver, and presses the brake valve 31. Controlled to supply air to the axle modulator 30. Further, when the vehicle 100 is unmanned, the first brake ECU 15A controls the brake valve 31 based on information such as the speed transmitted from the vehicle 100 or the like in front of the vehicle 100 to supply air to the axle modulator 30.

The axle modulator 30 is connected to a signal supply path 60 that communicates with the front wheel control unit 31A of the brake valve 31 and a supply path 61 that directly communicates with the front wheel brake tank 27. Further, the axle modulator 30 is connected to a safety module 32L provided corresponding to the front wheel 51 on the left side and a safety module 32R provided corresponding to the front wheel 51 on the right side. When the axle modulator 30 inputs an air pressure signal sent from the front wheel control unit 31A of the brake valve 31 via the signal supply path 60, the air directly supplied from the front wheel brake tank 27 via the supply path 61. Are distributed to the security modules 32L and 32R, respectively.

Since the left front wheel security module 32L and the right front wheel security module 32R have the same configuration, only the left front wheel security module 32L will be described. The safety module 32L is connected to the brake chamber 50 side via the shuttle valve 34. The safety module 32L is connected to a suspension tank 28 as an air supply source provided in the air suspension system (pneumatically driven suspension system) of the vehicle 100. The suspension tank 28 stores air supplied from the compressor 22 via the air dryer 23. The safety modules 32L and 32R may be connected to a tank other than the suspension tank 28. For example, the safety modules 32L and 32R may be connected to the parking brake tank 25, the rear wheel brake tank 26, and the front wheel brake tank 27.

The shuttle valve 34 is connected to the safety module 32L and the axle modulator 30 and allows air to flow from the safety module 32L side and the axle modulator 30 side, whichever has the higher pressure, to the brake chamber 50 side. Further, an ABS (Antilock Brake System) valve 36 is provided between the shuttle valve 34 and the brake chamber 50. The ABS valve 36 constitutes a front axle antilock braking system. The ABS valve 36 is controlled by the first brake ECU 15A. The ABS function may be possessed by the axle modulator 30.

The brake chamber 50 of the front wheel 51 has an air storage chamber for service brakes. The shuttle valve 34 is connected to the air storage chamber for the service brake via the ABS valve 36. When air is supplied to the air storage chamber for the service brake, the service brake is activated, and the braking force increases as the amount of air supplied increases. The service brake is released when air is discharged from the air storage chamber for the service brake.

Further, the front wheels 51 and the rear wheels 52 are provided with a vehicle speed sensor 58 that detects the rotational speed of the wheels. Further, a pressure sensor 54 for detecting the pressure in the supply path is provided in the pipeline connected to the air storage chamber for the service brake of the brake chamber 50.

On the other hand, the rear wheel brake tank 26 is connected to the axle modulator 40 via the rear wheel control unit 31B of the brake valve 31. The brake valve 31 supplies air to the axle modulator 40 from the rear wheel control unit 31B under the control of the first brake ECU 15A. The axle modulator 40 controls the supply and discharge of air to the brake chamber 50 provided in the rear wheel 52. The axle modulator 40 is connected to a signal supply path 62 that communicates with the rear wheel control unit 31B of the brake valve 31 and a supply path 63 that directly communicates with the rear wheel brake tank 26. Further, the axle modulator 40 is connected to a safety module 42L provided on the left rear wheel 52 and a safety module 42R provided on the right rear wheel 52. When the axle modulator 40 inputs an air pressure signal sent from the rear wheel control unit 31B of the brake valve 31 via the signal supply path 62, the axle modulator 40 receives the air sent from the rear wheel brake tank 26 via the supply path 63. It is distributed to the security modules 42L and 42R, respectively.

The first brake ECU 15A inputs a position detection signal from a sensor that detects the position of a brake pedal (not shown) operated by the driver when the vehicle 100 is driven by the driver, and presses the brake valve 31. Controlled to supply air to the axle modulator 40. Further, when the vehicle 100 is unmanned, the first brake ECU 15A controls the brake valve 31 based on information such as the speed transmitted from the vehicle 100 or the like in front of the vehicle 100 to supply air to the axle modulator 40. The axle modulator 40 may be controlled by a position detection signal output from a sensor that detects the position of the brake pedal.

Since the security module 42L for the rear wheel on the left side and the security module 42R for the rear wheel 52 on the right side have the same configuration, only the security module 42L on the left side will be described. The safety modules 42L and 42R of the rear wheels 52 have the same configuration except that the safety modules 32L and 32R of the front wheels 51 are connected to the tank and the like. The safety module 42L is connected to the brake chamber 50 side of the rear wheel 52 via the shuttle valve 34. The security module 42L has the same configuration as the security modules 32L and 32R provided for the front wheels 51. The safety modules 42L and 42R of the rear wheels 52 are also connected to the suspension tank 28.

The brake chamber 50 of the rear wheel 52 has an air storage chamber for a service brake and an air storage chamber for a parking brake. The brake chamber 50 is provided with a spring that applies an urging force to the wheels to stop the rotation of the wheels. When more than a predetermined amount of air is supplied to the air storage chamber for the parking brake, the spring is compressed by the air pressure to release the urging force on the wheels, and when the air is discharged from the air storage chamber for the parking brake, the spring The urging force is given to the wheels.

The safety modules 32L, 32R, 42L, 42R are controlled by the second brake ECU 15B. The second brake ECU 15B acquires the pressure detection signal of the pressure sensor 54. The second brake ECU 15B learns the relationship between the pressure and the deceleration based on the pressure detection signal. The deceleration is calculated by the second brake ECU 15B based on the speed acquired from the vehicle speed sensor 58 via the vehicle-mounted network 19. Alternatively, the second brake ECU 15B acquires the deceleration calculated by the platooning ECU 11 and the like from the vehicle-mounted network 19. The second brake ECU 15B controls the safety modules 32L, 32R, 42L, and 42R based on the deceleration request of the platooning ECU 11 and the learning result so that the vehicle 100 decelerates to a predetermined speed. The second brake ECU 15B may learn the relationship between speed and pressure in addition to the relationship between deceleration and pressure.

The parking brake tank 25 is connected to the parking brake control valve 55 and the parking brake relay valve 56. The parking brake control valve 55 is controlled by the platooning ECU 11 or the like to output an air pressure signal to the parking brake relay valve 56. When an air pressure signal is input from the parking brake control valve 55, the parking brake relay valve 56 supplies the air from the parking brake tank 25 to the parking brake air storage chamber of the brake chamber 50 of the rear wheel 52. As a result, the spring is compressed by the pressure of the air filled in the air storage chamber, and the parking brake is released. On the other hand, when the parking brake relay valve 56 does not input an air pressure signal from the parking brake control valve 55, air is discharged from the air storage chamber for the parking brake, and the parking brake is operated by the urging force of the spring. The parking brake relay valve 56 may be used as a solenoid valve and may be controlled by the first brake ECU 15A or the like.

A signal supply path 65 of the forced brake module 70 as an air supply unit is connected between the parking brake control valve 55 and the parking brake relay valve 56. One forced brake module 70 is provided for one vehicle 100. Further, the forced brake module 70 is controlled by the platooning ECU 11.

The forced brake module 70 has a signal input port connected to the signal supply path 65 and two connections connected to the safety module 32L, 32R side pipeline of the front wheel 51 and the safety module 42L, 42R side pipeline of the rear wheel 52. It includes a port and an input port connected to a tank-side supply path 66 to which air is supplied from the suspension tank 28. The forced brake module 70 can supply the air of the suspension tank 28 to the brake chamber 50 side via the safety modules 32L, 32R, 42L, and 42R. The forced brake module 70 cuts off the supply of air to the safety modules 32L, 32R, 42L, and 42R in a normal state, that is, in a normal state. Further, the forced brake module 70 supplies air to the brake chamber 50 side via the safety modules 32L, 32R, 42L, and 42R in a predetermined state in which an abnormality occurs to operate the forced brake. When air is supplied from the forced brake module 70, the pressure on the forced brake module 70 side is higher than that on the axle modulators 30 and 40, so that the shuttle valve 34 has air from the forced brake module 70 side to the brake chamber 50 side. Allow the flow of.

Next, with reference to FIG. 4, the configurations of the forced brake module 70 and the safety modules 32L, 32R, 42L, and 42R will be described in detail. Since the security modules 32L, 32R, 42L, and 42R have the same configuration, FIG. 4 shows in detail the configuration of the security module 42L of the rear wheel 52. In FIG. 4, the solid line connecting the tank and the actuator indicates an air passage, and the broken line connecting to the platooning ECU 11 or the second brake ECU 15B indicates a state in which they and the actuator are electrically connected.

The ignition switch of the vehicle 100 is off, indicating that the parking brake is activated. The platooning ECU 11, the first brake ECU 15A, and the second brake ECU 15B are all normal. The forced brake module 70 includes a first electromagnetic control valve 71, a forced brake release valve 72, a pneumatic control valve 73, and a relay valve 74 as a first relay valve. The first electromagnetic control valve 71, the forced brake release valve 72, and the air pressure control valve 73 are provided in the first passage 81 branching from the tank side supply path 66. The relay valve 74 has a signal input port 74P, and the signal input port 74P is connected to the first passage 81.

The first electromagnetic control valve 71 is a 3-port 2-position valve connected to the suspension tank 28 side, the exhaust passage 85 connected to the exhaust port 80 for discharging the air of the circuit, and the relay valve 74 side. The first electromagnetic control valve 71 is controlled by the platooning ECU 11, and has a connection position for communicating the tank side supply path 66 side and the forced brake release valve 72 side, and the forced brake release valve 72 side and the exhaust of the first passage 81. The position can be changed to the exhaust position connecting to the road 85. The first electromagnetic control valve 71 includes a valve spring 71S that applies an urging force so as to be in the connection position, and is in the connection position in the non-energized state and in the exhaust position in the energized state.

The forced brake release valve 72 is provided between the first electromagnetic control valve 71 and the pneumatic control valve 73 in the first passage 81. The forced brake release valve 72 is a 3-port 2-position valve connected to the first electromagnetic control valve 71 side of the first passage 81, the exhaust passage 85, and the air pressure control valve 73 side of the first passage 81. .. The forced brake release valve 72 is located at a connection position that connects the tank side supply path 66 side and the air pressure control valve 73 side, and at an exhaust position that connects the air pressure control valve 73 side and the exhaust path 85 in the first passage 81. Is configured to be changeable. The forced brake release valve 72 is provided with a valve spring 72S that applies an urging force so as to be in a connection position. Further, the forced brake release valve 72 has an operation unit 72A that is manually operated. The forced brake release valve 72 is in the connection position when the operation unit 72A is not manually operated, and is in the exhaust position when the operation unit 72A is manually operated.

The air pressure control valve 73 is a 3-port 2-position valve connected to the forced brake release valve 72 side, the exhaust passage 85, and the relay valve 74 side of the first passage 81 and controlled by an air pressure signal. The signal input port 73P of the pneumatic control valve 73 is connected to a signal supply path 65 extending from between the parking brake control valve 55 and the parking brake relay valve 56.

The parking brake relay valve 56 is connected to the air storage chamber 50B for the parking brake of the brake chamber 50. When air is discharged from the air storage chamber 50B of the brake chamber 50, the push rod 50E having the wedge 50D at the tip is extended by the urging force of the spring 50C of the brake chamber 50, and the wedge 50D is the brake lining of the rear wheel 52. It is inserted into (not shown) and the parking brake is activated. When air is supplied from the parking brake relay valve 56 to the air storage chamber 50B, the spring 50C is compressed, the push rod 50E moves in the direction of pulling out the wedge 50D from the wheel, and the parking brake is released. To.

The air pressure control valve 73 is configured to be repositionable to an exhaust position connecting the relay valve 74 side and the exhaust passage 85 and a connection position connecting the tank side supply passage 66 side and the relay valve 74 side. .. When the parking brake is operating, no air pressure signal is input to the signal input port 73P of the air pressure control valve 73, and an air pressure signal is sent from the parking brake control valve 55 to the relay valve 74 to release the parking brake. Occasionally, a pneumatic signal is input to the signal input port 73P. The pneumatic control valve 73 is provided with a valve spring 73S that applies an urging force so as to be at the exhaust position. The air pressure control valve 73 is in the exhaust position when no air pressure signal is input to the signal input port 73P, and is in the connection position when the air pressure signal is input.

The relay valve 74 is connected to a second passage 82 branching from the tank side supply passage 66, an exhaust passage 85, and a forced brake module connection passage 86 communicating with the safety modules 32L, 32R, 42L, and 42R for each wheel. It is a 3-port 2-position valve. The relay valve 74 inputs the air sent through the first passage 81 as an air pressure signal to the signal input port 74P. Further, the second passage 82 is, for example, a pipeline having an inner diameter larger than that of the first passage 81, and supplies a larger amount of air per unit time than the first passage 81 to the safety modules 32L, 32R, 42L, and 42R. It is possible. The relay valve 74 is configured to be repositionable to an exhaust position connecting the forced brake module connecting path 86 and the exhaust path 85, and a connecting position connecting the second passage 82 and the forced brake module connecting path 86. .. At the exhaust position, the air up to the shuttle valve 93 of the forced brake module connection path 86 is exhausted to the exhaust path 85. The relay valve 74 is provided with a valve spring 74S that applies an urging force so as to be in the exhaust position. The relay valve 74 is in the exhaust position when the air pressure signal is not input to the signal input port 74P, and is in the connection position when the air pressure signal is input. The relay valve 74 discharges air from the safety modules 32L, 32R, 42L, 42R at the exhaust position, and a large amount of air stored in the suspension tank 28 at the safety modules 32L, 32R, 42L, 42R at the connection position. Supply.

Next, the configurations of the security modules 32L, 32R, 42L, and 42R will be described in detail. Since the configurations of the security modules 32L, 32R, 42L, and 42R are the same as described above, only the configuration of the security module 42L will be described here. The safety module 42L includes a second electromagnetic control valve 90 and a third electromagnetic control valve 91 as safety electromagnetic control valves, a relay valve 92 as a second relay valve, and a shuttle valve 93.

The second electromagnetic control valve 90 and the third electromagnetic control valve 91 are provided in the third passage 83. One end of the third passage 83 is connected to the tank side supply passage 66, and the other end is connected to the exhaust passage 85. The second electromagnetic control valve 90 is configured so that the position can be changed between a shutoff position that shuts off the third passage 83 and a connection position that communicates with the third passage 83. The second electromagnetic control valve 90 is controlled by the second brake ECU 15B, and is in the cutoff position by the urging force of the valve spring 90S in the non-energized state, and is in the connection position in the energized state. The security modules 32L, 32R, and 42R other than the security module 42L are also provided with the third passage 83.

The position of the third electromagnetic control valve 91 can be changed between a connection position for communicating with the third passage 83 and a cutoff position for blocking the third passage 83. The third electromagnetic control valve 91 is controlled by the second brake ECU 15B, and becomes a connection position by the urging force of the valve spring 91S in the non-energized state, and becomes a shutoff position in the energized state.

The shuttle valve 93 includes a safety module connection path 87 connected between the forced brake module connection path 86, the second electromagnetic control valve 90 and the third electromagnetic control valve 91, and a signal supply path 88 connected to the relay valve 92. It is connected to the. The shuttle valve 93 allows air to flow from the forced brake module connecting path 86 and the security module connecting path 87, whichever has the higher pressure, to the signal supply path 88 side. The signal supply path 88 is connected to the signal input port 92P of the relay valve 92. The forced brake module connection path 86 is also connected to the safety modules 32L, 32R, and 42R other than the safety module 42L.

The relay valve 92 is a 3-port 2-position valve connected to a fourth passage 84 branching from the tank-side supply passage 66, an exhaust passage 85, and a chamber connection passage 89 connected to the brake chamber 50. The inner diameter of the fourth passage 84 is larger than, for example, the signal supply path 88, and a larger amount of air can be supplied per unit time than the signal supply path 88. A large amount of air is supplied from the tank side supply path 66 from the fourth passage 84. The security modules 32L, 32R, and 42R other than the security module 42L are also provided with the fourth passage 84.

The relay valve 92 is configured so that the position can be changed to an exhaust position connecting the chamber connection path 89 and the exhaust path 85 and a connection position connecting the fourth passage 84 and the chamber connection path 89. Further, the relay valve 92 is provided with a valve spring 92S that applies an urging force so as to be in the exhaust position. When the air pressure signal is not input to the signal input port 92P, the relay valve 92 is in the exhaust position, and the air in the chamber connection path 89 is discharged to the exhaust path 85. Further, the relay valve 92 becomes a connection position when an air pressure signal is input, and supplies a large amount of air in the fourth passage 84 to the chamber connection path 89.

A shuttle valve 34 is connected to the chamber connecting path 89. The shuttle valve 34 is connected to the safety module 42L, the axle modulator 40 controlled by the first brake ECU 15A, and the air storage chamber 50A for the service brake of the brake chamber 50. Other safety modules 32L, 32R, and 42R are also connected to the brake chamber 50 provided on each wheel via the shuttle valve 34 (see FIG. 3) and the shuttle valve 34.

A pressure sensor 53 is provided in the connection path connecting the shuttle valve 34 and the brake chamber 50. The pressure sensor 53 outputs a signal corresponding to the pressure of the connecting path to the first brake ECU 15A, the second brake ECU 15B, and the like. The second brake ECU 15B learns the relationship between pressure and deceleration based on the pressure detection signal output from the pressure sensor 53 when the axle modulators 30 and 40 supply air to the brake chamber 50. The deceleration is calculated by the second brake ECU 15B, or the deceleration calculated by the first brake ECU 15A or the platooning ECU 11 is acquired via the vehicle-mounted network 19. The second brake ECU 15B may learn the relationship between speed and pressure in addition to the relationship between deceleration and pressure.

When the vehicle 100 transitions from the state in which the parking brake is activated to the state in which the vehicle 100 can travel, the platooning ECU 11 energizes the first electromagnetic control valve 71 to bring it to the exhaust position. Further, the platooning ECU 11 controls the parking brake control valve 55 to supply air from the parking brake relay valve 56 to the brake chamber 50. The air pressure control valve 73 inputs an air pressure signal to the signal input port 73P and becomes a connection position. As a result, the forced brake can be operated.

Next, with reference to FIGS. 5 to 9, each mode of the pneumatic brake system 20 will be described together with the operations of the forced brake module 70 and the safety modules 32L, 32R, 42L, and 42R. The pneumatic brake system 20 has a normal traveling mode, a deceleration traveling mode, a forced braking mode, and a re-traveling mode. The security modules 32L, 32R, 42L, and 42R will be described focusing on the operation of the security module 42L corresponding to the rear wheel 52 on the left side. Further, in FIGS. 5 to 9, a thick solid line indicates a state in which air is supplied in the air passage, and a thick broken line indicates a state in which air is discharged in the air passage. Further, the broken line connected to the platooning ECU 11 or the second brake ECU 15B indicates a state in which they and the actuator are electrically connected.

The deceleration running mode by the second brake ECU 15B will be described with reference to FIGS. 5 and 6. In the deceleration driving mode, the ignition switch is on and the parking brake is released. The deceleration running mode is executed when an abnormality occurs in the first brake ECU 15A and normal brake control cannot be executed. Specifically, the deceleration brake mode is executed in the following cases.

-When an abnormality occurs only in the first brake ECU 15A and the platooning ECU 11 and the second brake ECU 15B are normal.
-When an abnormality occurs in the first brake ECU 15A and one platooning ECU 11, and the second brake ECU 15B and the other platooning ECU 11 are normal.

As shown in FIG. 5, the normal platooning ECU 11 maintains the first electromagnetic control valve 71 in the energized state when it detects the occurrence of an abnormality in the first brake ECU 15A. Further, the platooning ECU 11 determines whether or not deceleration is necessary based on the speed and deceleration of the vehicle 100 or the like traveling in front, the speed input from the vehicle speed sensor 58, and the like. When the platoon traveling ECU 11 determines that deceleration is necessary, it outputs a deceleration instruction to the second brake ECU 15B.

When the second brake ECU 15B inputs the deceleration instruction, the second electromagnetic control valve 90 and the third electromagnetic control valve 91 are energized. The second electromagnetic control valve 90 is in the connection position, and the third electromagnetic control valve 91 is in the shutoff position. The air sent from the tank-side supply path 66 is supplied to the safety module connection path 87 via the second electromagnetic control valve 90. As a result, the safety module connection path 87 of the security module connection path 87 and the forced brake module connection path 86 becomes high pressure, so that the shuttle valve 93 supplies air from the security module connection path 87 to the signal supply path 88.

As a result, an air pressure signal is input from the security module connection path 87 to the signal input port 92P of the relay valve 92, and the relay valve 92 becomes the connection position. Then, air is supplied from the tank side supply path 66 to the chamber connection path 89 via the relay valve 92 at the connection position. Since it is premised that an abnormality has occurred in the first brake ECU 15A in the deceleration running mode, the supply of air from the axle modulators 30 and 40 is stopped. Therefore, of the chamber connection path 89 side and the axle modulators 30 and 40 side, the chamber connection path 89 has a high pressure, so that the shuttle valve 34 moves from the chamber connection path 89 to the air storage chamber 50A for the service brake of the brake chamber 50. Supply air.

FIG. 6 shows a state in which the vehicle 100 is not decelerated in the deceleration travel mode. When the platooning ECU determines that the vehicle 100 should not decelerate, the platooning ECU stops the output of the deceleration instruction to the second brake ECU 15B while maintaining the first electromagnetic control valve 71 in the energized state. When the output of the deceleration instruction from the platooning ECU 11 is stopped, the second brake ECU 15B de-energizes the second electromagnetic control valve 90 and the third electromagnetic control valve 91.

The second electromagnetic control valve 90 is in the shutoff position and the third electromagnetic control valve 91 is in the connection position, so that the air in the signal supply path 88 passes through the shuttle valve 93, a part of the third passage 83, and the exhaust path 85. It is discharged from the discharge port 80 through. As a result, the relay valve 92 becomes the exhaust position, and the air in the air storage chamber 50A for the service brake of the brake chamber 50 is discharged from the exhaust port 80 through the shuttle valve 34, the relay valve 92, and the exhaust passage 85. As a result, the service brake is released.

In the deceleration running mode, the second brake ECU 15B inputs a pressure detection signal from the pressure sensor 54, and the second electromagnetic control is performed so that the pressure in front of the brake chamber 50 becomes the pressure corresponding to the target deceleration. The energization and de-energization of the valve 90 and the third electromagnetic control valve 91 are repeated.

Next, the forced braking mode will be described with reference to FIG. 7. At this time, the ignition switch is on and the parking brake is released. The forced braking mode is executed in the following cases.

-When a state in which an abnormality has occurred in both of the platooning ECU 11 is included.
-When the first brake ECU 15A and the second brake ECU 15B include a state in which an abnormality has occurred.

In the forced brake mode, the first electromagnetic control valve 71 is in a non-energized state. When an abnormality occurs in both the platooning ECU 11, the first electromagnetic control valve 71 is naturally de-energized. The air pressure control valve 73 becomes a connection position when an air pressure signal is supplied to the signal input port 73P. The relay valve 74 becomes a connection position by inputting an air pressure signal to the signal input port 74P. At this time, if the amount of air sent to the relay valve 74 as an air pressure signal is small, the time from when the first electromagnetic control valve 71 is de-energized until the relay valve 74 reaches the connection position can be shortened. .. When the relay valve 74 is in the connection position, a large amount of air stored in the suspension tank 28 is sent to the forced brake module connection path 86.

By sending air to the forced brake module connecting path 86 via the relay valve 74, the pressure of the forced brake module connecting path 86 becomes higher than that of the safety module connecting path 87. Therefore, the shuttle valve 93 distributes air from the forced brake module connection path 86 to the signal supply paths 88 connected to the security modules 32L, 32R, 42L, and 42R, respectively.

The relay valve 92 of the security module 42L becomes a connection position by inputting an air pressure signal to the signal input port 92P. As a result, a large amount of air stored in the suspension tank 28 passes through the tank side supply passage 66, the fourth passage 84, the relay valve 92, and the shuttle valve 34, and the air storage chamber 50A for the service brake of the brake chamber 50. Will be sent to. As a result, the forced brake is activated.

Next, the rerun mode will be described with reference to FIGS. 8 and 9. The re-traveling mode is a mode for re-driving the vehicle 100 by driving by the driver after the forced brake is activated. By re-running the vehicle 100 at a predetermined speed after the forced brake is activated, the driver can move the vehicle 100 to a nearby maintenance site or the like.

As shown in FIG. 8, immediately after the forced brake is activated, the first electromagnetic control valve 71, the second electromagnetic control valve 90, and the third electromagnetic control valve 91 are in a non-energized state. Further, after the forced brake is activated, the parking brake is activated by another control system, so that the air pressure control valve 73 is in the exhaust position.

The rerun mode is started when the operation unit 72A of the forced brake release valve 72 is operated by the driver. Further, since the air pressure control valve 73 is in the exhaust position and the air in the first passage 81 is discharged from the exhaust port 80, the relay valve 74 is in the exhaust position. As a result, the air in the forced brake module connection path 86 is supplied to the exhaust path 85 and discharged from the exhaust port 80.

Further, since the second electromagnetic control valve 90 is in the shutoff position and the third electromagnetic control valve 91 is in the connection position, air is not supplied to the third passage 83, and the second electromagnetic control valve 90 and the second electromagnetic control are controlled. The air in the passage between the valves 90 is supplied to the exhaust passage 85 and discharged from the exhaust port 80. As a result, since the forced brake module connection path 86 and the safety module connection path 87 do not supply air to the shuttle valve 93 side, no air pressure signal is input to the signal input port 92P of the relay valve 92. As a result, the relay valve 92 becomes the exhaust position. Then, while the parking brake is still operated by the urging force of the spring 50C, the air in the air storage chamber 50A for the service brake of the brake chamber 50 is discharged from the exhaust port 80 through the exhaust passage 85.

As shown in FIG. 9, when the parking brake is released by a normal ECU or another brake control system, an air pressure signal is input to the signal input port 73P of the air pressure control valve 73, and the air pressure control valve 73 becomes a connection position. .. At this time, even if the air pressure control valve 73 is in the connection position, the forced brake release valve 72 is maintained in the exhaust position, so that air is not supplied from the forced brake module 70. When decelerating the vehicle 100, the driver operates the brake pedal provided on the brake valve 31 (see FIG. 3). When the brake pedal is activated, an air pressure signal is input from the brake valve 31 to the axle modulators 30 and 40. When the axle modulator 30 inputs the air pressure signal, the air directly supplied from the front wheel brake tank 27 via the supply path 61 is distributed to the safety modules 32L and 32R, respectively. The air supplied to the safety modules 32L and 32R is supplied to the air storage chamber for the service brake of the brake chamber 50, and the service brake of the front wheel 51 operates. Further, the axle modulator 40 supplies air to the service brake air storage chamber 50A of the brake chamber 50 via the shuttle valve 34 to operate the service brake of the rear wheel 52.

As described above, according to the above embodiment, the effects listed below can be obtained.
(1) The pneumatic braking system includes four safety modules 32L, 32R, 42L and 42R. Therefore, as compared with the case where there is only one security module, even if an abnormality occurs in at least one of the security modules, the brake is applied by the other security module, so that the safety of the pneumatic braking system can be further improved.

(2) The forced brake module 70 can distribute air to a plurality of safety modules 32L, 32R, 42L, 42R in a supply system different from the axle modulators 30 and 40 controlled by the first brake ECU 15A. Therefore, even if there is an abnormality in the supply system including the axle modulators 30 and 40, the brake can be forcibly operated.

(3) The forced brake module 70 can forcibly operate the brake. This makes it possible to improve security.
(4) One forced brake module 70 is provided for the plurality of security modules 32L, 32R, 42L, 42R. Therefore, the number of parts can be reduced as compared with the case where an air supply unit for supplying an air pressure signal is provided for each of the safety modules 32L, 32R, 42L, and 42R.

(5) Since the forced brake module 70 distributes air as an air pressure signal to the plurality of safety modules 32L, 32R, 42L, 42R, it is necessary to supply a large amount of air. The forced brake module 70 includes a relay valve 74 that is controlled by a small amount of air, which is an air pressure signal, and supplies a larger amount of air than the air pressure signal. Therefore, when the first electromagnetic control valve 71 is de-energized, a large amount of air stored in the suspension tank 28, which is an air supply source, is transferred to the plurality of safety modules 32L, 32R, 42L, and 42R in a short time. Can be distributed.

(6) Since the first electromagnetic control valve 71 of the forced brake module 70 outputs an air pressure signal to the relay valve 74 when the force is off, when an abnormality occurs in the platooning ECU 11 that controls the first electromagnetic control valve 71, An air pressure signal can be output to the relay valve 74 to activate the service brake. Therefore, the safety of the pneumatic brake system 20 can be improved.

(7) Since the air pressure control valve 73 supplies air to the relay valve 74 when the parking brake is released, the brake is applied via the air pressure control valve 73 and the relay valve 74 only when the parking brake is released. Air can be supplied to the chamber 50 side to activate the safety service brake.

(8) The relay valve 92 of the safety modules 32L, 32R, 42L, 42R brakes a large amount of air stored in the suspension tank 28, which is an air supply source, when a small amount of air, which is an air pressure signal, is supplied. It can be supplied to the chamber 50 side. Therefore, it is possible to shorten the operation time from the start of the output of the air pressure signal to the relay valve 92 to the operation of the service brake. Further, the air pressure signal can be supplied to the relay valve 92 from the forced brake module connecting path 86 and the safety module connecting path 87, whichever has the higher pressure, via the shuttle valve 93. That is, both the system for supplying air from the forced brake module 70 to the brake chamber 50 and the system for supplying air from the second electromagnetic control valve 90 and the third electromagnetic control valve 91 to the brake chamber 50 are connected to the brake chamber 50. Since the relay valve 92 for supplying air can be shared, the number of parts can be reduced.

The above embodiment can be modified as appropriate and implemented as follows.
-In the above embodiment, it is assumed that the leading vehicle 100a and the following vehicle 100b are equipped with the same platooning control system 10. Instead of this, the leading vehicle 100a may not be equipped with the platooning control system 10, or may be equipped with a platooning control system different from that of the following vehicle 100b.

-In the above embodiment, the configurations of the security modules 32L, 32R, 42L, and 42R are the same. Instead of this, the configurations of the security modules 32L, 32R, 42L, and 42R may be different from each other. Alternatively, a plurality of modules of 4 or less of the security modules 32L, 32R, 42L, and 42R may be the same.

-In the above embodiment, the deceleration running mode is set to "when an abnormality occurs only in the first brake ECU 15A and the platooning ECU 11 and the second brake ECU 15B are normal" and "in the first brake ECU 15A and one platooning ECU 11". When an abnormality occurs and the second brake ECU 15B and the other platooning ECU 11 are normal, the execution is performed. However, even in other cases, if the brake controlled by the first brake ECU 15A does not operate normally or may not operate normally, the deceleration traveling mode may be performed. In this way, the safety of the pneumatic braking system can be further enhanced.

-In the above embodiment, the forced brake mode is executed in "a case where an abnormality has occurred in both the platooning ECU 11" and "a case where an abnormality has occurred in the first brake ECU 15A and the second brake ECU 15B". I tried to be done. However, even in other cases, if the brake controlled by the first brake ECU 15A does not operate normally or may not operate normally, if an abnormality occurs in one of the platooning ECU 11, the other When the communication state with the vehicle 100 is not good, the forced braking mode may be performed. In this way, the safety of the pneumatic braking system can be further enhanced.

-In the above embodiment, "when an abnormality occurs only in the first brake ECU 15A and the platooning ECU 11 and the second brake ECU 15B are normal", "an abnormality occurs in the first brake ECU 15A and one of the platooning ECUs 11". The deceleration running mode is performed when the second brake ECU 15B and the other platooning ECU 11 are normal. In addition to this, even when an abnormality occurs in the second brake ECU 15B, the deceleration running mode can be set to further enhance the safety.

-In the above embodiment, it is assumed that the pneumatic braking system has a normal driving mode, a deceleration driving mode, a forced braking mode, and a re-driving mode. However, the pneumatic braking system only needs to have a normal running mode, at least a deceleration running mode, and a forced braking mode, and if there is a means for rerunning the vehicle 100 after the forced braking is activated, the pneumatic braking system has the above rerun mode. You don't have to.

-In the above embodiment, the forced brake module 70 and the safety modules 42L and 42R on the rear wheel 52 side are connected. In addition to this, a load sensing valve (pressure adjusting valve) may be provided in the middle of the pipeline connecting the forced brake module 70 and the safety modules 42L and 42R. The load sensing valve can adjust the amount of air supplied to the air storage chamber for the service brake of the brake chamber 50. The load sensing valve has a port that connects to the air suspension system. The pressure at this port will be the same as the air suspension system. When the load of the load of the vehicle 100 is large, the pressure of the port becomes large. When the pressure on the port side of the load sensing valve becomes larger than a predetermined value, the load sensing valve increases the amount of air supplied to the safety modules 42L and 42R of the rear wheels 52, which are the driving wheels. The load sensing valve may be provided in the pipeline connecting the forced brake module 70 and the safety modules 32L and 32R on the front wheel 51 side.

-In the above embodiment, the safety modules 32L, 32R, 42L, and 42R are shuttles that allow air to flow from the higher pressure side of the forced brake module connection path 86 and the security module connection path 87 to the signal supply path 88 side. A valve 93 is provided. Instead, an actuator is provided to switch the flow from the forced brake module connection path 86 to the signal supply path 88 side and the flow from the security module connection path 87 to the signal supply path 88 side by pneumatic control or electrical control. It may be.

In the above embodiment, the forced brake module 70 includes an air pressure control valve 73 that inputs air as an air pressure signal from the brake chamber 50 side when the parking brake is released. Instead, the forced brake module 70 may include an electromagnetic control valve that is electrically controlled as the parking brake is activated and released. For example, when the parking brake system is electrically controlled, an electromagnetic control valve can be preferably used. In this way, the responsiveness can be further improved by using the electromagnetic control valve instead of the pneumatic control valve.

-In the above embodiment, the forced brake module 70 includes a first electromagnetic control valve 71 that supplies air supplied from the suspension tank 28 to the relay valve 74 when the suspension tank 28 is not energized. Instead of this, the first electromagnetic control valve 71 may supply the air supplied from the suspension tank 28 to the relay valve 74 when the power is turned on.

-In the above embodiment, the forced brake module 70 includes a relay valve 74 as a first relay valve. Alternatively, the pneumatic control valve 73 may be connected to the shuttle valve 93 to omit the relay valve 74.

-In the above embodiment, the forced brake module 70 that distributes air to a plurality of safety modules 32L, 32R, 42L, 42R is provided. Instead of this, one forced brake module 70 may be provided for the front wheel safety modules 32L and 32R, and one forced brake module 70 may be provided for the rear wheel safety modules 42L and 42R. Alternatively, one forced brake module 70 may be provided for each of the security modules 32L, 32R, 42L, and 42R.

10 ... platooning control system, 11, 11A, 11B ... platooning ECU, 15A ... first brake ECU as first brake control device, 15B ... second brake ECU as second brake control device, 19 ... in-vehicle network, 20 ... Pneumatic brake system, 21 ... Air storage tank, 28 ... Suspension tank as an air supply source, 30, 40 ... Axle modulator, 31 ... Brake valve, 32L, 32R, 42L, 42R ... Safety module, 34 ... Shuttle valve , 36 ... ABS valve, 50 ... Brake chamber, 58 ... Vehicle speed sensor, 54 ... Pressure sensor, 55 ... Parking brake control valve, 56 ... Parking brake relay valve, 66 ... Tank side supply path, 70 ... Forced as air supply unit Brake module, 71 ... 1st electromagnetic control valve, 72 ... Forced brake release valve, 73 ... Pneumatic control valve, 74 ... Relay valve, 80 ... Discharge port, 85 ... Exhaust path, 86 ... Forced brake module connection path, 87 ... Security Module connection path, 88 ... Signal supply path, 90 ... Second electromagnetic control valve as security electromagnetic control valve, 91 ... Third electromagnetic control valve as security electromagnetic control valve, 92 ... Relay as second relay valve Brake, 93 ... Shuttle valve, 100 ... Vehicle.

Claims (9)

In a pneumatic braking system that supplies and discharges air from an air source to a braking mechanism that activates and deactivates the vehicle's service brakes.
A module for supply and discharge of air to normally the brake mechanism when,
Each brake mechanism is provided with a safety module for supplying and discharging air to the brake mechanism.
A pneumatic braking system characterized in that when the module does not operate, the safety module supplies and discharges air to the braking mechanism on behalf of the module. A switching unit for switching between the supply of air from the module to the brake mechanism and the supply of air from the safety module to the brake mechanism is further provided.
The pneumatic braking system according to claim 1. The module is controlled by the first brake control device.
The safety module is controlled by a second brake control device.
The pneumatic braking system according to claim 1 or 2. Wherein a different supply system from the air supply source and the supply system including the module, the air supplied from the air supply source, claim 1-3 comprising an air supply unit for distributing a plurality of the security module as a pneumatic signal The pneumatic braking system according to any one of the above. The pneumatic braking system according to claim 4 , wherein the safety module is provided for each wheel, and one air supply unit is connected to each of the safety modules. The air supply unit is stored in the air supply source for a plurality of the safety modules, depending on the presence or absence of the electromagnetic control valve that supplies the air supplied from the air supply source as an air pressure signal and the presence or absence of the air pressure signal. The pneumatic braking system according to claim 4 or 5 , further comprising a first relay valve that distributes air. The pneumatic braking system according to claim 6 , wherein the electromagnetic control valve supplies air supplied from the air supply source to the first relay valve when the power is not supplied. The air supply unit includes an air pressure control valve that inputs air as an air pressure signal from the brake mechanism side when the parking brake is released.
The air pressure control valve becomes a connection position for supplying air to the first relay valve when the air pressure signal is input, and stops supplying air to the first relay valve when the air pressure signal is not input. The pneumatic braking system according to claim 6 or 7 , wherein the position is to be used. The security module, acceptable and security solenoid control valve which is controlled by the second brake control device, the flow of air from the higher pressure side of said first relay valve side to the safety solenoid valve side 6. comprising a shuttle valve and a second relay valve for supplying air stored in the air supply when entering the air supplied from the shuttle valve side as air pressure signal to the brake mechanism side to The pneumatic braking system according to any one of 8 to 8 .