JPH07132819A - Electric control air brake system - Google Patents

Abstract

PURPOSE:To provide good responsibility almost without changing the conventional pedal feeling, and to further improve a fail safe system. CONSTITUTION:When a brake pedal 2 is applied, a pedal switch 35 is turned on, and a front wheel side control signal pressure leak preventive valve 20 and a rear wheel side first control signal pressure leak preventive valve 27 are closed by a first ECU 36, while a rear wheel side second control signal pressure leak preventive valve 29 is closed by a second ECU 37. The control signal pressure generated on the sides of the first and second output ports 3b, 3d of a brake valve 3 is detected by rear wheel side first pressure sensors 19, 26, and a front wheel side control signal pressure feeding valve 23 is opened by the first ECU 36, while a rear wheel side control signal pressure feeding valve 32 is opened by the second ECU 37. Since the control signal pressure is introduced from air tanks 14, 17 into rear wheel side relay valves 4, 6, the compressed air in the air tanks 14, 17 is fed to rear wheel side brake actuators 8, 9, 11, 12, thus operating the brake for front and rear wheels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically controlled air brake system having a good response by electrically controlling compressed air as a braking medium to perform braking, and particularly to an electrically controlled air brake system. The present invention relates to an electrically controlled air brake system capable of reliably braking even in the event of a failure.

[0002]

2. Description of the Related Art Conventionally, an air brake system that uses compressed air as a braking medium has been adopted as a brake system for large vehicles such as buses and trucks. Conventionally, this air brake system is operated by a driver. The compressed air from the air tank is directly supplied to the brake actuator through the brake valve and the compressed air from the air tank is supplied to the control room of the relay valve as a braking instruction signal through the brake valve to switch the relay valve. Accordingly, there is an air brake system that supplies compressed air from an air tank to a brake actuator through a relay valve.

As one of such conventional air brake systems, there is an air brake system 1'as shown in FIG. This air brake system 1'comprises two systems, a front wheel brake system A and a rear wheel brake system B. When not in operation, the brake pedal 2 is released, and the dual brake valve 3 has a first input port 3a and a first brake port 3a. The first output port 3b is blocked, the second input port 3c and the second output port 3d are blocked, and the first output port 3b and the second output port 3d are in communication with the discharge port 3e. Therefore,
When not in operation, the inside of the control chamber 4a of the front wheel side relay valve 4 communicates with the atmosphere through the passage 5 and the inside of the control chamber 6a of the rear wheel side relay valve 6 communicates with the atmosphere through the passage 7. Therefore, the output port 4c of the front-wheel-side relay valve 4 is connected to the input port 4b.
And the output port 6c of the rear-wheel-side relay valve 6 is blocked from the input port 6b and communicates with the discharge port 6d. Therefore, the front wheel side brake actuators 8, 9 are in communication with the atmosphere through the passage 10, the output port 4c and the discharge port 4d, and the rear wheel side brake actuators 11, 12 are for the passage 13,
It communicates with the atmosphere through the output port 6c and the discharge port 6d.

When the brake pedal 2 is depressed for braking, the first input port 3a and the first output port 3 of the brake valve 3 are depressed.
b and the second input port 3c and the second output port 3d communicate with each other, and the first output port 3b and the second output port 3
d and the outlet 3e are cut off. As a result, the compressed air in the front-wheel side air tank 14 is transferred to the passage 15, the brake valve 3,
Introduced as a control signal into the control room 4a through the passage 5,
The output port 4c of the relay valve 4 communicates with the input port 4b and shuts off from the discharge port 4d. As a result, the compressed air in the air tank 14 is supplied to the front wheel side brake actuators 8 and 9 through the passage 16, the input port 4b, the output port 4c and the passage 10, and the front wheel brake operates. At the same time, the compressed air in the front wheel side air tank 14 is introduced as a control signal into the control chamber 6a through the passage 15, the brake valve 3, and the passage 7, and the output port 6c of the relay valve 6 communicates with the input port 6b and is discharged. Shut off from exit 6d. As a result, the compressed air in the rear wheel side air tank 17 is supplied to the rear wheel side brake actuators 11 and 12 through the passage 18, the input port 6b, the output port 6c and the passage 13, and the rear wheel brake operates.

In such an air brake system 1 ', when the vehicle becomes large, the brake valve 3 provided near the driver's seat to the brake actuator 1 for the rear wheel.
Since the brake pipe 7 up to 1 and 12 is considerably long,
After the driver depresses the brake pedal 2, it takes a considerable time for the compressed air to flow to the brake actuators 11 and 12 of the rear wheels to reach the actuator operating pressure, resulting in a delay in the response of the brake.

Therefore, in order to improve the responsiveness of such an air brake system, an electromagnetic valve is provided in the air brake system, the operation of the brake valve by the driver is electrically detected, and the electromagnetic signal is generated by the electric signal. By electrically controlling the opening and closing of the, electrically controlled air brake system to perform air brake operation, for example, U.S. Pat.
No. 492.

As shown in FIG. 5, in the electric control air brake system 100 of this US patent, when the driver depresses the brake pedal 101 and operates the brake operating valve 102 for braking, the pedal switch 103 is turned on, and The ON signal is supplied to the controller 105 via the controller 104. The controller 105 receives the ON signal and operates the pressure control valves 106 and 107, which are electromagnetic valves, so that the air tank 1
08 compressed air passes through the pressure control valve 106 and the double check valve 109, and the left and right front wheel brake actuator 1
The compressed air in the air tank 112 is supplied to the left and right rear wheel brake actuators 113 and 114 through the pressure control valve 107 while being supplied to the 10,111.

According to this electrically controlled air brake system 100, since the pressure control valves 106, 107 and the air tanks 108, 112 are provided near the brake actuators 110, 111, 113, 114, respectively, the piping from the air tanks 108, 112 to the brake actuators 110, 111, 113, 114 is shortened, and the driver Since the brake pedal depressing operation is changed to an electric signal and the pressure control valves 106 and 107 are controlled by the electric signal, the pressure control valves 106 and 107 are activated in a short time after the driver depresses the brake pedal. Therefore, when the driver depresses the brake pedal 101, the brake actuators 110, 111, 113, 114 are quickly activated, and the responsiveness of the air brake is improved.

In such an electrically controlled air brake system, if the electrically controlled system fails, the pressure control valves 106 and 107, which are solenoid valves, are no longer reliably controlled, and the compressed air in the air tanks 108 and 112 is changed to the brake actuator. There is a risk that it will not be sent to 110, 111, 113, 114. Therefore, in the electric control air brake system 100 of the aforementioned US patent, the brake operation valve 102 is opened by depressing the brake pedal 101. Therefore, when the electric control system fails, the compressed air from the air tank 115 operates the brake. It is supplied to the brake actuators 110 and 111 on the front wheel side through the valve 102, the passage 116, and the double check valve 109. As a result, the brake can be reliably operated even when the electric control system fails.

[0010]

By the way, in the electric control air brake system 100 of this US patent, the pedal depression amount or the pedal depression force of the driver is converted into an electric signal by the pedal switch 103, and the pressure control valve is operated by the electric signal. Since 106 and 107 are controlled to operate, in order to make the brake pressure of the brake actuators 110, 111; 113 and 114 the pressure corresponding to the pedal depression amount or the pedal depression force, the electric signal output from the pedal switch 103 is the pedal depression amount. Alternatively, the size needs to be adjusted according to the pedal effort. For this reason, the structure of the pedal switch 103 is inevitably complicated, and resistance to pedal depression increases.

If such a pedal switch 103 is to be incorporated into the conventional brake operating valve 102, the brake operating valve 102 will have to be redesigned significantly, and the cost of the brake operating valve 102 will increase. Not only that, the compatibility with the brake operating valve of the conventional air brake system may be impaired. Further, when the pedal switch 103 is incorporated in the brake operation valve 102, the pedal feeling is different from the conventional feeling, and not only the pedal feeling needs to be adjusted but also the adjustment becomes extremely difficult.

Further, in the electric control air brake system of the above-mentioned US patent, the pressure control valves 106, 10 of the front and rear wheel brake systems are controlled by an electric signal from one pedal switch 103.
Failsafe is not always sufficient because 7 is controlled, that is, the electric control system is one system.

The present invention has been made in view of the above problems, and an object thereof is to provide a good response without changing the pedal feel of the conventional brake valve without changing the conventional brake valve. It is an object of the present invention to provide an electrically controlled air brake system capable of achieving the desired characteristics and further improving the fail-safe.

[0014]

In order to solve the above-mentioned problems, the invention of claim 1 has an input port, an output port connectable to this input port, and a discharge port connectable to the output port. However, when the brake pedal is released, the discharge port communicates with the output port, and when the brake pedal is stepped on, the output port is blocked from the discharge port and the brake valve connected to the input port is connected to the input port. An air tank that is always connected and that stores compressed air, a brake actuator that generates a braking force, a control chamber, an input port, an output port that can be connected to this input port, and an exhaust port that can be connected to this output port,
Normally, when the output port is connected to the exhaust port and a control signal pressure is introduced into the control chamber, the output port is disconnected from the exhaust port and connected to the input port, and a brake for the brake actuator is provided. A first valve connecting a relay valve for controlling the supply and discharge of pressure, a first passage connecting the output port of the brake valve and the control chamber of the relay valve, and a first passage connecting the input port of the relay valve and the air tank Two passages, a third passage that connects the output port of the relay valve and the brake actuator, a fourth passage that connects the control chamber of the relay valve and the air tank, and a first passage are provided. , A normally-open control signal pressure leakage prevention valve consisting of a solenoid valve, and the control signal pressure leakage prevention valve provided in parallel with the control signal pressure leakage prevention valve. When the pressure difference with the flow side is a predetermined pressure or more, a one-way valve that allows only the flow of compressed air from the upstream side to the downstream side and a normally closed valve that is provided in the fourth passage and that is an electromagnetic valve A control signal pressure supply valve, a normally closed control signal pressure discharge valve including a solenoid valve for discharging the control signal pressure of the control chamber of the relay valve, the output port of the brake valve, and the control signal pressure leak prevention valve A first pressure sensor that detects the pressure in the first passage between the first and second passages, a second pressure sensor that detects the pressure in the brake actuator, a normally open pedal switch that is turned on when the brake pedal is depressed, and the control An electronic control device for electrically controlling the brake operation by electrically connecting the signal pressure leak prevention valve, the control signal pressure supply valve, the control signal pressure discharge valve, the first and second pressure sensors, and the pedal switch. It is characterized in that it comprises.

Further, the invention of claim 2 is such that a first input port, a first output port connectable to the first input port, a second input port, a second output port connectable to the second input port, and The first,
The exhaust port is connectable to the second output port, the exhaust port communicates with the first and second output ports when the brake pedal is released, and the first and second output ports are connected when the brake pedal is depressed. A dual brake valve that is disconnected from the exhaust port and is connected to the first and second input ports;
A first brake system side air tank that is always connected to the input port and stores compressed air, a first brake system side brake actuator that generates a braking force, a control room, an input port, an output port that can be connected to this input port, There is a discharge port connectable to this output port, and when the control signal pressure is introduced into the control chamber while the output port is normally connected to the output port, the output port is blocked from the discharge port. And a first brake system side relay valve that is connected to the input port and controls supply and discharge of brake pressure to and from the first brake system side brake actuator, the first output port of the brake valve and the first brake system side A first brake system side first passage connecting the control chamber of the relay valve, the input port of the first brake system side relay valve and the first brake system The connecting the side air tank 1
Brake system side second passage, first brake system side third passage connecting the output port of the first brake system side relay valve and the first brake system side brake actuator, and the first brake system side relay A first brake system side fourth passage connecting the control chamber of the valve and the first brake system side air tank, and a normally open first brake provided in the first brake system side first passage and formed of an electromagnetic valve. The system side control signal pressure leakage prevention valve is provided in parallel with the first brake system side control signal pressure leakage prevention valve, and the pressure difference between the upstream side and the downstream side of the first brake system side control signal pressure leakage prevention valve. Is equal to or higher than a predetermined pressure, the first brake system side one-way valve that allows only the flow of compressed air from the upstream side to the downstream side, and the first brake system side fourth passage, A normally closed first brake system side control signal pressure supply valve, and a normally closed first brake system side control signal pressure discharge valve for discharging the control signal pressure of the control chamber of the first brake system side relay valve. , A first brake system side first pressure sensor for detecting a pressure in the first brake system side first passage between the first output port of the brake valve and the first brake system side control signal pressure leakage prevention valve When,
A first brake system side second pressure sensor that detects the pressure of the first brake system side brake actuator, a second brake system side air tank that stores compressed air, and a second brake system side brake actuator that generates a braking force. A control chamber, an input port, an output port connectable to the input port, and an exhaust port connectable to the output port. Normally, the output port is connected to the exhaust port and a control signal is sent to the control chamber. A second brake system side relay valve for controlling the supply and discharge of brake pressure to and from the second brake system side brake actuator, the output port being blocked from the discharge port and connected to the input port when pressure is introduced. ,
A second brake system side first passage connecting the second output port of the brake valve and the control chamber of the second brake system side relay valve, the input port of the second brake system side relay valve, and the A second brake system side second passage connecting the second brake system side air tank, a second brake system side connecting the output port of the second brake system side relay valve and the second brake system side brake actuator. The third passage, the second brake system side fourth passage connecting the control chamber of the second brake system side relay valve and the second brake system side air tank, and the second brake system side first passage A normally open second brake system side first control signal pressure leakage prevention valve that is provided close to the brake valve and that is an electromagnetic valve, and the second brake system side first control valve. When the pressure difference between the upstream side and the downstream side of the second brake system side first control signal pressure leak prevention valve is provided in parallel with the signal pressure leak prevention valve and is equal to or more than a predetermined pressure, the upstream side to the downstream side. Second brake system side first one-way valve that allows only the flow of compressed air, and a second brake system side first passage that is provided close to the second brake system side relay valve and is composed of an electromagnetic valve. The normally open second brake system side second control signal pressure leakage prevention valve and the second brake system side second control signal pressure leakage prevention valve are provided in parallel, and the second brake system side second control signal pressure leakage leak is provided. When the pressure difference between the upstream side and the downstream side of the prevention valve is equal to or higher than a predetermined pressure, the second brake system side second one-way valve that allows only the flow of compressed air from the upstream side to the downstream side; 2 Brake system side 4th passage A normally closed second brake system side control signal pressure supply valve, and a normally closed second brake system side control signal pressure discharge valve for discharging the control signal pressure of the control chamber of the second brake system side relay valve, A second brake system side first pressure for detecting the pressure in the second brake system side first passage between the second output port of the brake valve and the second brake system side first control signal pressure leakage prevention valve A sensor, a second brake system side second pressure sensor for detecting the pressure of the second brake system side brake actuator, the first brake system side control signal pressure leak prevention valve, the first brake system side control signal pressure supply valve,
The first brake system side control signal pressure discharge valve, the first brake system side first and second pressure sensors, the second brake system side first pressure sensor, the second brake system side first control signal pressure leak prevention valve , And a first electronic control device that electrically connects the pedal switch to control the brake operation of the first brake system, and the second brake system side second
The control signal pressure leak prevention valve, the second brake system side control signal pressure supply valve, the second brake system side control signal pressure discharge valve, and the second brake system side second pressure sensor are electrically connected. And a second electronic control unit that is electrically connected to the first electronic control unit and controls the brake operation of the second brake system.

Further, the invention according to claim 3 has an input port, an output port connectable to the input port, and a discharge port connectable to the output port, and when the brake pedal is released, the discharge port is the output port. And a brake valve connected to the input port while the output port is blocked from the discharge port when the brake pedal is stepped on, and the brake valve is always connected to the input port,
An air tank that stores compressed air, a brake actuator that generates a braking force, a first passage that connects the output port of the brake valve and the brake actuator, and a second passage that connects the brake actuator and the air tank. And provided in the first passage,
A normally open brake pressure leakage prevention valve consisting of a solenoid valve and the brake pressure leakage prevention valve are provided in parallel, and when the pressure difference between the upstream side and the downstream side of the brake pressure leakage prevention valve is a predetermined pressure or more, the A one-way valve that allows only the flow of compressed air from the upstream side to the downstream side, a normally closed brake pressure supply valve that is provided in the second passage and that is an electromagnetic valve, and the brake pressure of the brake actuator is discharged. A normally closed brake pressure discharge valve, a first pressure sensor for detecting the pressure in the first passage between the output port of the brake valve and the brake pressure leakage prevention valve, and the brake actuator. Second pressure sensor for detecting the pressure of the brake pedal, a normally open pedal switch that is turned on when the brake pedal is depressed, the brake pressure leakage prevention valve, the brake pressure supply valve, and the brake Exhaust valve, said first, second pressure sensor, and the pedal switch is characterized by comprising a are electrically connected an electronic control device for controlling the brake actuation.

Further, in the invention of claim 4, a first input port, a first output port connectable to the first input port, a second input port, a second output port connectable to the second input port, and The first,
The exhaust port is connectable to the second output port, the exhaust port communicates with the first and second output ports when the brake pedal is released, and the first and second output ports are connected when the brake pedal is depressed. A dual brake valve that is disconnected from the exhaust port and is connected to the first and second input ports;
A first brake system side air tank which is always connected to the input port and stores compressed air, a first brake system side brake actuator which generates a braking force, the first output port of the brake valve and the first brake system side 1st brake system side to connect with brake actuator 1st
A passage, a first brake system side second passage that connects the first brake system side brake actuator and the first brake system side air tank, and a solenoid valve provided in the first brake system side first passage The normally open first brake system side brake pressure leakage prevention valve is provided in parallel with the first brake system side brake pressure leakage prevention valve.
When the pressure difference between the upstream side and the downstream side of the brake system side brake pressure leakage prevention valve is equal to or more than a predetermined pressure, the first brake system side one-way valve that allows only the flow of compressed air from the upstream side to the downstream side. And a normally closed first brake system side brake pressure supply valve that is provided in the first brake system side second passage and includes an electromagnetic valve, and a normally closed first brake system side brake actuator discharge brake pressure. A pressure in the first brake system side first passage between the first brake system side brake pressure discharge valve, the first output port of the brake valve and the first brake system side brake pressure leakage prevention valve is detected. A first brake system side first pressure sensor, a first brake system side second pressure sensor that detects the pressure of the first brake system side brake actuator, and a second brake system that stores compressed air. And · The system side air tank, a second for connecting the second brake system side brake actuator that generates a braking force, the second output port of the brake valve and the second brake system side brake actuator
Brake system side first passage, second brake system side second passage connecting the second brake system side brake actuator and the second brake system side air tank, and the second brake system side first passage with the brake. A first brake pressure leakage prevention valve, which is provided close to the valve, and which is a normally open second brake system side and is formed in parallel with the second brake system side first brake pressure leakage prevention valve, and 2 brake system side When the pressure difference between the upstream side and the downstream side of the first brake pressure leakage prevention valve is a predetermined pressure or more, the second brake system side that allows only the flow of compressed air from the upstream side to the downstream side A first one-way valve and a second normally open second brake system side second solenoid valve provided in the first passage of the second brake system close to the second brake system side brake actuator. The rake pressure leakage prevention valve and the second brake system side second brake pressure leakage prevention valve are provided in parallel, and the pressure difference between the upstream side and the downstream side of the second brake system side second brake pressure leakage prevention valve is A second brake system side second one-way valve that allows only the flow of compressed air from the upstream side to the downstream side when the pressure is equal to or higher than a predetermined pressure, and a solenoid valve provided in the second brake system side second passage. A normally closed second brake system side brake pressure supply valve, a normally closed second brake system side brake pressure discharge valve for discharging the brake pressure of the second brake system side brake actuator, and the first of the brake valves. A second brake system side first pressure sensor for detecting a pressure in the second brake system side first passage between the second output port and the second brake system side first brake pressure leakage prevention valve; and the second brake. The second brake system side detects the pressure of the mains brake actuator 2
A pressure sensor, the first brake system side brake pressure leak prevention valve, the first brake system side brake pressure supply valve, the first brake system side brake pressure discharge valve, the first brake system side first and second pressures A sensor, the second pressure sensor side first pressure sensor, the second pressure brake system side first brake pressure leak prevention valve, and the pedal switch are electrically connected to control the brake operation of the first pressure brake system. 1 electronic control unit, the second brake system side second brake pressure leakage prevention valve, the second brake system side brake pressure supply valve, the second brake system side brake pressure discharge valve, and the second brake system side first A second electronic that is electrically connected to the two pressure sensors and is electrically connected to the first electronic control unit to control the brake operation of the second brake system. It is characterized in that it consists of a control device.

Further, a fifth brake system side wheel speed sensor electrically connected to the first electronic control unit for detecting a wheel speed of a wheel corresponding to the first brake system, Electrically connected to the second electronic control unit,
A second brake system side wheel speed sensor for detecting a wheel speed of a wheel corresponding to the second brake system is provided, and the first electronic control device is an anti-skid brake control and a traction control in the first brake system. And the second electronic control unit performs at least one of antiskid brake control and traction control in the second brake system.

[0019]

In the electronically controlled air brake system of the present invention having the above-described structure, the electronic control unit quickly closes the control signal pressure leak valve when the brake pedal is depressed, so that the control is performed at the output side of the brake valve. The signal pressure rises quickly. The control signal pressure is detected by the first pressure sensor with almost no delay, and by the electric signal of the control signal pressure and the electric signal of the brake pressure of the brake actuator detected by the second pressure sensor,
An electronic control device controls the opening and closing of the control signal pressure supply valve and the control signal pressure discharge valve. As a result, the air brake can be actuated with almost no response delay, and good responsiveness can be obtained.

When the control signal pressure supply valve does not open due to the failure of the electric control system, the control signal pressure is introduced into the control chamber of the relay valve through the one-way valve. As a result, even when the control signal pressure supply valve is not opened, the air brake can be operated reliably, and the fail-safe function can be exerted.

In particular, in the second aspect of the invention, the electronically controlled air brake system is constituted by two systems, a first brake system and a second brake system, and the electric control and the air brake control of these two systems are independent of each other. Done. As a result, the fail-safe function can be exerted more reliably.

Further, in the third aspect of the invention, when the brake pedal is depressed, the electronic control unit quickly closes the brake pressure leak valve, so that the brake pressure rapidly rises on the output side of the brake valve. The brake pressure is detected by the first pressure sensor with almost no delay, and the electronic control unit causes the brake pressure supply valve and the brake to operate by the electric signal of the brake pressure and the electric signal of the brake pressure of the brake actuator detected by the second pressure sensor. Controls the opening and closing of the pressure discharge valve. As a result, the air brake can be actuated with almost no response delay, and good responsiveness can be obtained.

When the brake pressure supply valve does not open due to the failure of the electric control system, the brake pressure is introduced into the brake actuator through the one-way valve. As a result, the air brake can be reliably operated even when the brake pressure supply valve is not opened, and the fail-safe function can be exerted.

Particularly, in the invention of claim 4, the electronically controlled air brake system is constituted by two systems of a first brake system and a second brake system, and electric control and air brake control of these two systems are independently performed. Done.
As a result, the fail-safe function can be exerted more reliably.

Further, in the fifth aspect of the invention, the electronic control unit controls the opening and closing of the brake pressure supply valve and the brake pressure discharge valve based on the wheel speed from the wheel speed sensor, whereby the antiskid brake control and the traction control are performed. At least one of.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of an electrically controlled air brake system according to the present invention. The same components as those of the conventional air brake shown in FIG. 4 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the electrically controlled air brake system 1 according to this embodiment has a front wheel side first pressure sensor 1 provided in a passage 5 in a front wheel brake system A.
9 and a front wheel side control signal pressure leak prevention valve 20 consisting of a normally open two-position solenoid valve, and this front wheel side control signal pressure leak prevention valve 2
0 is provided in parallel with the front wheel side control signal pressure leak prevention valve 20 and flows from the brake valve 3 side to the relay valve 4 side when the pressure difference between the brake valve 3 side and the relay valve 4 side is a predetermined pressure or more. Front wheel one-way valve 21 that allows only
And a passage 22 that connects the air tank 14 and the control chamber 4a.
Front wheel side control signal pressure supply valve 23, which is a normally closed two-position solenoid valve, and a normally closed two-position solenoid valve for discharging air from the control chamber 4a of the relay valve 4. The signal pressure discharge valve 24 and the front wheel side second pressure sensor 25 provided in the passage 10 are provided respectively, and the rear wheel brake system B is provided in the passage 7 close to the brake valve 3. A rear wheel side first control signal pressure leakage prevention valve 27 including a wheel side first pressure sensor 26 and a normally open two-position solenoid valve, and a first control in parallel with the rear wheel side first control signal pressure leakage prevention valve 27. Signal pressure leak prevention valve 27
The first rear one-way valve 28 on the rear wheel side, which is provided in a bypass manner and allows only the flow from the brake valve 3 side to the relay valve 6 side when the pressure difference between the brake valve 3 side and the relay valve 6 side is a predetermined pressure or more. And a second rear wheel side which is a normally open two-position solenoid valve provided in the passage 7 close to the relay valve 6.
The control signal pressure leakage prevention valve 29 and the second control signal pressure leakage prevention valve 29 are provided in parallel with the second control signal pressure leakage prevention valve 29 to bypass the brake signal 3 side and the relay valve 6.
The rear wheel side second one-way valve 30 that allows only the flow from the brake valve 3 side to the relay valve 6 side when the pressure difference on the side is a predetermined pressure or more, and the air tank 17 and the control chamber 6a of the relay valve 6 are connected. A rear wheel side control signal pressure supply valve 32 formed of a normally closed two-position solenoid valve provided in the passage 31 and a normally closed two-position solenoid valve for discharging air in the control chamber 6a. A control signal pressure discharge valve 33 and a rear wheel side second pressure sensor 34 provided in the passage 13 are provided respectively, and further, the brake valve 3 or its vicinity is simply turned on or off by depressing or releasing the brake pedal 2. A normally open pedal switch 35 that is turned off, a front wheel side first pressure sensor 19, a front wheel side control signal pressure leak prevention valve 20, a front wheel side control signal pressure supply valve 23, a front wheel side control signal pressure discharge valve 2
4, a front wheel side second pressure sensor 25, a rear wheel side first pressure sensor 26, a rear wheel side first control signal pressure leakage prevention valve 27, and a pedal switch 35 are electrically connected to each other by a first electronic control unit ( Hereinafter, also referred to as a first ECU) 36, a rear wheel side second control signal pressure leak prevention valve 29, a rear wheel side control signal pressure supply valve 32, a rear wheel side control signal pressure discharge valve 33, a rear wheel side second pressure sensor. 34 and a second electronic control unit (hereinafter, also referred to as a second ECU) 37 to which the first ECU 36 is electrically connected.

In the electric control air brake system 1 of the present embodiment having such a structure, when the brake pedal 2 is depressed for braking, the pedal switch 35 is turned on and the pedal depression signal is input to the first ECU 36.
The first ECU 36 sends a control signal to the second ECU 37 by this signal, and the front wheel side control signal pressure leakage prevention valve 20
And the rear wheel side first control signal pressure leakage prevention valve 27 is closed.
Further, the second ECU 37 closes the rear wheel side second control signal pressure leak prevention valve 29 by the signal from the first ECU 36.

On the other hand, since the brake valve 3 is opened by depressing the brake pedal 2, control signal pressure is generated by the compressed air from the air tank 14 on the first and second output ports 3b and 3d side of the brake valve 3. At this time, since the front wheel side control signal pressure leakage prevention valve 20 and the rear wheel side first control signal pressure leakage prevention valve 27 are closed and the one-way valves 21, 28 are closed until the pressure reaches a predetermined pressure, the brake valve 3 The compressed air that is sent out is the front wheel side control signal pressure leak prevention valve 20.
And the rear wheel side first control signal pressure leakage prevention valve 27 does not flow out to the downstream side, and as a result, the first and second brake valves 3
The control signal pressure on the side of the output ports 3b, 3d rises with almost no delay according to the amount of depression of the brake pedal 2 or the pedal effort.

First and second output ports 3 of the brake valve 3
The control signal pressures generated on the b and 3d sides are detected by the front wheel side first pressure sensor 19 and the rear wheel side first pressure sensor 26, respectively, and converted into electric signals of a magnitude corresponding to the magnitudes of the control signal pressures. Is supplied to. First ECU 36
Sends an electric signal of this control signal pressure to the second ECU 37 and opens the front wheel side control signal pressure supply valve 23. Thereby, the control signal pressure by the compressed air from the air tank 14 is introduced into the control chamber 4a of the front wheel side relay valve 4, so that the relay valve 4 is switched and the compressed air in the air tank 14 is input to the input port 4b, the output port 4c and the passage 10. It is supplied to the left and right front wheel side brake actuators 8 and 9 through which the front wheel brakes operate. At this time, the compressed air introduced from the front wheel side control signal pressure supply valve 23 has the brake valve 3 because the front wheel side control signal pressure leakage prevention valve 20 is closed.
The pressure in the control chamber 4a rises with almost no delay.

Further, the front wheel side brake actuator 8,
The pressure of the compressed air supplied to 9 is detected by the front wheel side second pressure sensor 25 and sent to the first ECU 36. The first ECU 36 includes front wheel brake actuators 8 and 9
When it is determined that the pressure of the above corresponds to the pressure corresponding to the pedal depression amount, the front wheel side control signal pressure supply valve 23 is closed. As a result, compressed air is not introduced into the control chamber 4a any more, so that the control signal pressure is maintained at the current pressure and the relay valve 4 is in the neutral state, that is, the output port 4c is the input port 4b.
Also, both the discharge port 4d and the discharge port 4d are shut off. As a result, the compressed air is not further supplied to the brake actuators 8 and 9 on the front wheel side from the output port 4c and is not discharged from the discharge port 4d. Therefore, the pressure of the brake actuators 8 and 9 on the front wheel side is equal to the pedal depression amount or the pedal depression amount. The pressure is maintained corresponding to the pedal effort.

On the other hand, by the signal from the first ECU 36,
The second ECU 37 opens the rear wheel side control signal pressure supply valve 32. As a result, the control signal pressure generated by the compressed air in the air tank 17 is introduced into the control chamber 6a of the relay valve 6 on the rear wheel side, so that the relay valve 6 is switched and the air tank 17
Compressed air passes through the input port 6b, the output port 6c and the passage 13 and the left and right rear wheel side brake actuators 11, 12
The brakes on the rear wheels are activated. At this time, the compressed air introduced from the rear wheel side control signal pressure supply valve 32 does not flow out to the brake valve 3 side because the rear wheel side second control signal pressure leak prevention valve 29 is closed, and therefore, The pressure in the control chamber 6a rises with almost no delay.

Further, the rear wheel side brake actuator 1
The pressure of the compressed air supplied to 1, 12 is detected by the rear wheel side second pressure sensor 34 and sent to the second ECU 37. The second ECU 37 closes the rear wheel side control signal pressure supply valve 32 when determining that the pressure of the rear wheel side brake actuators 11 and 12 has reached the pressure corresponding to the pedal depression amount. As a result, since compressed air is not introduced into the control chamber 6a any more, the control signal pressure is maintained at the pressure at that time, and the relay valve 6 is in the neutral state, that is, the output port 6c is neither the input port 6b nor the discharge port 6d. It will be shut off. As a result, the brake actuator 1 on the rear wheel side
No compressed air is supplied to the output terminals 1 and 12 from the output port 6c, and the compressed air is not discharged from the exhaust port 6d. Therefore, the pressure of the brake actuators 11 and 12 on the rear wheel side is maintained at the pressure corresponding to the pedal depression amount. .

When the depression amount of the brake pedal 2 is reduced to weaken the braking force, the compressed air on the first and second output ports 3b and 3d side of the brake valve 3 is discharged according to the depression amount. Becomes smaller. This change in the control signal pressure is detected by the front wheel side first pressure sensor 19 and the rear wheel side first pressure sensor 26 and sent to the first ECU 36, and further the change in the control signal pressure on the rear wheel side is changed from the first ECU 36 to the second ECU 37. Sent to. 1st EC
U36 opens the front wheel side control signal pressure discharge valve 24 to discharge the compressed air in the control chamber. As a result, the front-wheel-side relay valve 4 is switched and the output port 4c and the discharge port 4d are communicated with each other, so that the compressed air of the front-wheel-side brake actuators 8 and 9 is discharged and the pressure of the front-wheel-side brake actuators 8 and 9 drops. To do. If the first ECU 36 determines that the pressure of the front wheel side brake actuators 8 and 9 detected by the front wheel side second pressure sensor 25 has reached the pressure corresponding to the depression amount after the change of the brake pedal 2, the front wheel side control signal pressure discharge is performed. Close valve 24. Therefore, the compressed air in the control chamber 4a is not discharged any more, and the front-wheel-side relay valve 4
Becomes neutral again, and the pressure of the front wheel side brake actuators 8 and 9 does not drop further, and is maintained at the pressure corresponding to the amount of brake pedal depression.

Similarly, in the rear wheel side brake system B,
The rear wheel side control signal pressure discharge valve 33 opens and the control signal pressure in the control chamber 6a drops. As a result, the relay valve 6 on the rear wheel side is switched, and the brake actuator 1 on the rear wheel side is switched.
The pressure of 1,12 drops. When the second ECU 37 determines that the pressure of the rear-wheel brake actuators 11 and 12 detected by the rear-wheel second pressure sensor 34 has reached the pressure corresponding to the depression amount of the brake pedal 2, the rear-wheel control signal pressure discharge is performed. The valve 33 is closed. The compressed air in the control chamber 6a is not discharged any more, the rear-wheel-side relay valve 6 becomes neutral again, and the rear-wheel-side brake actuator 1
The pressures 1 and 12 do not drop any further, and are maintained at the pressures corresponding to the brake pedal depression amount.

When the brake pedal 2 is released to release the brake, the pedal switch 35 is turned off and the first and second output ports 3b and 3d of the brake valve 3 are released.
Since the compressed air on the side is discharged from the discharge port 3e and the control signal pressure drops, the first ECU 36 opens the front and rear wheel side first control signal pressure leakage prevention valves 20, 27, and the second ECU 37
Opens the rear wheel side second control signal pressure leak prevention valve 29 and opens the front and rear wheel side control signal pressure discharge valves 24 and 33. Therefore, the front and rear wheel side brake actuators 8, 9;
The pressure of 2 drops.

Finally, when the brake pressure signal of the front wheel side brake actuators 8 and 9 from the second front wheel side pressure sensor 25 becomes 0, the first ECU 36 closes the front wheel side control signal pressure discharge valve 24 and the rear wheel side second pressure sensor. 2 The pressure signal from the rear wheel side brake actuators 11 and 12 from the pressure sensor 16 is 0
Then, the second ECU 37 determines that the rear wheel side control signal pressure discharge valve 3
Close 3. Thus, the electrically controlled air brake system 1 is brought into the non-actuated state shown in FIG.

Thus, the electrically controlled air brake system 1
Is an electric signal of the control signal pressure with almost no delay detected by the front and rear wheel side first pressure sensors 19 and 26 and the front and rear wheel side brakes detected by the front and rear wheel side second pressure sensors 25 and 34. Actuators 8, 9; 11, 12
1st, 2nd ECU3 by the electric signal of the brake pressure of
6, 37 are front wheel side control signal pressure supply valves 23, rear wheel side control signal pressure supply valves 32, and front and rear wheel side control signal pressure discharge valves 2.
Since the Nos. 4 and 33 are controlled, the front and rear wheel air brakes can be actuated with almost no response delay, and good responsiveness can be obtained.

By the way, the front wheel side control signal pressure supply valve 23 or the rear wheel side control signal pressure supply valve 32 is connected to the first ECU 36.
Alternatively, even if a signal is sent from the second ECU 37, the switch cannot be opened due to mechanical failure such as sticking, and the switch cannot be opened.
6, electrical wiring, the first ECU36 or the second ECU37
Etc. and the front wheel side control signal pressure supply valve 23 or the rear wheel side control signal pressure supply valve 32 is switched due to a failure of the electrical system such as no signal being sent from the first ECU 36 or the second ECU 37. In some cases, it may not open without opening. In this case, the electric brake cannot be operated by electric control. However, in this embodiment, the air brake can be reliably operated even in such a case.

That is, assume that the front wheel side control signal pressure supply valve 23 is fixed, for example. Brake pedal 2
When is depressed, the pedal switch 35 is turned on in the same manner as described above, and the front wheel side control signal pressure leakage prevention valve 20, the rear wheel side first control signal pressure leakage prevention valve 27, and the rear wheel side second control signal pressure leakage leak. The prevention valve 29 closes. In addition, the brake valve 3
Is opened, the first output port 3b of the brake valve 3 is opened.
The control signal pressure on the side is detected by the front wheel side first pressure sensor 19 and the electric signal is sent to the first ECU 36. The first ECU 36 tries to open the front-wheel-side control signal pressure supply valve 23, but the front-wheel-side control signal pressure supply valve 23 does not open because it is fixed. Therefore, the compressed air from the air tank 14 is not introduced into the control chamber 4a of the relay valve 4 through the front wheel side control signal pressure supply valve 23.

However, since the control signal pressure on the output side of the brake valve 3 gradually rises, the pressure difference before and after the front wheel side control signal pressure leakage prevention valve 20 becomes large. When this pressure difference becomes equal to or larger than the set value, the front wheel side one-way valve 21 is opened, and the control signal pressure is introduced from the brake valve 3 into the control chamber 4a of the front wheel side relay valve 4. Therefore, the front wheel side relay valve 4 is switched, compressed air in the air tank 14 is supplied from the output port 4c to the front wheel side brake actuators 8 and 9, and the front wheel air brake is operated. In this way, the front wheel air brake can be reliably operated even if the front wheel side control signal pressure supply valve 23 does not open due to a failure.

If the depression amount of the brake pedal 2 is reduced in order to weaken the braking force of the front wheel air brake,
The control signal pressure at the output port of the brake valve 3 drops. At this time, the compressed air in the control chamber 4a is not discharged through the passage 5 because of the front wheel side one-way valve 21. However, as in the case where the second control signal pressure supply valve 23 is normal, the pressure signal from the front wheel side first pressure sensor 19 causes the first EC
Since U36 opens the front wheel side discharge valve 24, the compressed air in the control chamber 4a is discharged through the front wheel side discharge valve 24, and the control chamber 4
The control signal pressure of a falls. Therefore, the pressure of the front wheel side brake actuators 8 and 9 drops, and the braking force is weakened. When the pressure of the front wheel side brake actuators 8 and 9 detected by the front wheel side second pressure sensor 25 becomes a pressure corresponding to the depression amount of the brake pedal 2, the first ECU 36 closes the front wheel side discharge valve 24 in the same manner as described above. The pressure of the front wheel side brake actuators 8 and 9 is kept constant.

When the operation of the front wheel air brake is released, the brake pedal 2 is released. The operation after releasing the brake pedal 2 is almost the same as in the normal case described above, and thus the description thereof is omitted. The same applies when the rear-wheel-side control signal pressure supply valve 32 cannot be opened, and the description thereof will be omitted.

FIG. 2 shows another embodiment of the present invention, which is shown in FIG.
It is a circuit diagram similar to. The same components as those of the embodiment shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The embodiment shown in FIG. 1 is an embodiment in which the present invention is applied to an electrically controlled air brake system using a relay valve, but this embodiment does not use a relay valve as shown in FIG. It is an example when the present invention is applied to an electrically controlled air brake system.

As shown in FIG. 2, front wheel side brake pressure leakage consisting of a normally open two-position solenoid valve is provided in a brake pressure passage 38 connecting the first output port 3b of the brake valve 3 and the front wheel side brake actuators 8 and 9. A prevention valve 39 is provided, and a front wheel side brake pressure supply valve 41, which is a normally closed two-position solenoid valve, is provided in a brake pressure passage 40 that connects the air tank 14 and the front wheel side brake actuators 8 and 9. . Further, there is provided a front wheel side brake pressure discharge valve 42 which is a normally closed two-position solenoid valve for discharging the brake pressure of the front wheel side brake actuators 8 and 9.

On the other hand, the second output port 3d of the brake valve 3
A rear wheel side first brake pressure leakage prevention valve 44, which is a normally open two-position solenoid valve, is provided in the brake pressure passage 43 connecting the rear wheel side brake actuators 11 and 12 close to the brake valve 3. In addition, a rear wheel side second brake pressure leakage prevention valve 45, which is a normally open two-position solenoid valve, is provided close to the rear wheel brake actuators 11 and 12. Further, a rear wheel side brake pressure supply valve 47, which is a normally closed two-position solenoid valve, is provided in a brake pressure passage 46 that connects the rear wheel side air tank 17 and the rear wheel side brake actuators 11 and 12. Further, a rear wheel side brake pressure discharge valve 48, which is a normally closed two-position solenoid valve that discharges the brake pressure of the rear wheel side brake actuators 11 and 12, is provided.

By the way, since the relay valve is used in the embodiment shown in FIG. 1, each two-position solenoid valve controls the control signal pressure in the control chamber of the relay valve. Since not used, each two-position solenoid valve directly controls the brake pressure in the brake actuator. As described above, the two-position solenoid valves of the present embodiment and the two-position solenoid valves of the embodiment shown in FIG. 1 are different from each other only in the pressure to be controlled and correspond to each other. Pressure leakage prevention valve 39 and front wheel side control signal pressure leakage prevention valve 20, front wheel side brake pressure supply valve 41 and front wheel side control signal pressure supply valve 23, front wheel side brake pressure discharge valve 42 and front wheel side control signal pressure discharge valve 24, A rear wheel side first brake pressure leakage prevention valve 44, a rear wheel side first control signal pressure leakage prevention valve 27, a rear wheel side second brake pressure leakage prevention valve 45 and a rear wheel side second control signal pressure leakage prevention valve 29, The rear wheel side brake pressure supply valve 47 corresponds to the rear wheel side control signal pressure supply valve 32, and the front wheel side brake pressure discharge valve 48 corresponds to the rear wheel side control signal pressure discharge valve 33.

Therefore, the first ECU 36 and the second E
The control of each two-position solenoid valve by the CU 37 is shown in FIG.
Since the operation of the electrically controlled air brake system in this embodiment is the same as that of the embodiment shown in FIG. 1, the description thereof will be omitted. To do.

FIG. 3 shows still another embodiment of the present invention.
It is a circuit diagram similar to FIG. The same components as those of the embodiment shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The embodiment shown in FIG. 1 is an embodiment in which the present invention is applied to an electrically controlled air brake system having only a service brake. However, this embodiment has a brake pressure so as to prevent wheel lock during braking. Anti-skid brake control (hereinafter also referred to as ABS) system that adjusts the traction control, and traction control control (hereinafter, T) that controls the brake pressure of the drive wheels to prevent idling of the drive wheels.
This is an example of the case in which the present invention is applied to an electrically controlled air brake system including a system (also referred to as RC).

As shown in FIG. 3, in this embodiment, T
In order to perform RC, the rear wheels, which are the driving wheels, need to be independently brake-controlled on the left and right. Left and right are provided independently. The left and right rear wheel side brake systems BL and BR are provided with the same components as the rear wheel brake system B shown in FIG. The components provided in the left rear wheel side brake system BL have the same reference numerals as the components shown in FIG. 1 with L added, and the components provided in the right rear wheel side brake system BR are the components shown in FIG. The same reference numerals as in FIG.

As shown in FIG. 3, the passage 7 is located on the downstream side of the rear wheel side first control signal pressure leak valve 27 and on the left rear wheel side brake system B.
It is branched into a left side passage 7L of L and a right side passage 7R of the right rear wheel side brake system BR. Left rear wheel side brake system BL
Include left rear wheel side passages 13L, 18L, 31L, left rear wheel side relay valve 6L, left rear wheel side brake actuator 1
1, left rear wheel side second control signal pressure leak prevention valve 29L, left rear wheel side second one-way valve 30L, left rear wheel side control signal pressure supply valve 32
L, the left rear wheel side control signal pressure discharge valve 33L, and the left rear wheel side second pressure sensor 34L are provided respectively, and the right rear wheel side brake system BR includes the right rear wheel side passages 13R, 18R, 31.
R, right rear wheel side relay valve 6R, right rear wheel side brake actuator 12, right rear wheel side second control signal pressure leakage prevention valve 2
9R, a right rear wheel side second one-way valve 30R, a right rear wheel side control signal pressure supply valve 32R, a right rear wheel side control signal pressure discharge valve 33R, and a right rear wheel side second pressure sensor 34R, respectively. There is.

Further, the front wheel brake system A is provided with left and right front wheel side wheel speed sensors 51 and 52 for detecting the wheel speeds of the left and right front wheels 49 and 50, respectively. The wheel speed sensors 51 and 52 are the first ECU 36.
It is connected to the. The wheel speeds of the left and right front wheels 49, 50 detected by the left and right front wheel side wheel speed sensors 51, 52 are supplied to the first ECU 36, respectively, and
The power is supplied from the first ECU 36 to the second ECU 37. On the other hand, left and right rear wheel brake systems BL, BR
Also, similarly, left and right rear wheel side wheel speed sensors 55 and 56 for respectively detecting wheel speeds of the left and right rear wheels 53 and 54 are provided. These left and right rear wheel side wheel speed sensors 55, 5
6 is connected to the second ECU 37. Then, the left and the left detected by the rear wheel side wheel speed sensors 55, 56,
The wheel speeds of the right rear wheels 53 and 54 are supplied to the second ECU 37, respectively, and are transmitted from the second ECU 37 to the first ECU 3
6 is supplied.

The first ECU 36 has left and right front wheels 49, 50.
Is calculated based on the wheel speeds of the left and right rear wheels 53, 54, and the left side during braking based on the calculation results.
When the locking tendency of at least one of the right front wheels 49 and 50 is detected, the front wheel control signal pressure is adjusted in order to adjust the brake pressures of the left and right front wheel side brake actuators 8 and 9 so as to eliminate the locking tendency. The supply valve 23 and the front wheel side control signal pressure discharge valve 24 are controlled respectively. Further, the second ECU 37 calculates based on the wheel speeds of the left and right front wheels 49 and 50 and the wheel speeds of the left and right rear wheels 53 and 54, and based on the calculation results, the left and right rear wheels 53, 54 during braking. When the locking tendency of at least one rear wheel of 54 is detected, the left rear wheel side control signal pressure is adjusted in order to adjust the brake pressures of the left and right rear wheel side brake actuators 11 and 12 so as to eliminate the locking tendency. The supply valve 32L and the left rear wheel side control signal pressure discharge valve 33L, and the right rear wheel side control signal pressure supply valve 32R and the right rear wheel side control signal pressure supply valve 33R are controlled, respectively. Thus, the first ECU 36 and the second ECU 37 perform the ABS control when the wheel lock tendency is detected during braking.

On the other hand, the second ECU 37 controls the left and right front wheels 4
It is calculated based on the wheel speed of 9,50 and the wheel speed of the left and right rear wheels 53, 54, and based on the calculation result, at least one of the rear wheels of the left, right rear wheels 53, 54 is idling. When the tendency is detected, in order to suppress the idling tendency, the left and right rear wheel side control signal pressure supply valves 32L and 32R of the left and right rear wheels 53 and 54 having the idling tendency are opened and braked. The brake pressure is supplied to the actuators 11 and 12 to brake the rear wheels, which tend to idle, and to the left,
In order to adjust the brake pressure of the brake actuators 11 and 12 on the right rear wheel side, the left rear wheel side control signal pressure supply valve 32L
And left rear wheel side control signal pressure discharge valve 33L, right rear wheel side control signal pressure supply valve 32R, and right rear wheel side control signal pressure supply valve 33R
Control the opening and closing of each. In this way, the second ECU 37 performs the TRC control at the time of detecting the drive wheel slip tendency at the time of starting or sudden acceleration.

The operation of the service brake in this embodiment is the same as that of the embodiment shown in FIG. 1 except that the brakes on the rear wheels are independently operated on the left and right sides, and a description thereof will be omitted. Although the pedal switch 35 is used to open and close the control signal pressure leakage prevention valves 20, 26 and 29 in the above-described embodiments, the first pressure sensors 19 and 26 may be used instead.

In each of the above-described embodiments constructed as described above, the pedal switch 3 is simply turned on and off.
Since only 5 is provided in or near the dual brake valve 3, the dual brake valve 3 is
The conventional dual brake valve can be used as it is without requiring a large design change to the conventional dual brake valve. Moreover, the structure of the pedal switch 35 can be simple. Furthermore, in the passage of the conventional air brake system shown in FIG. 4,
Since it is only necessary to add the passages 22 and 31, it is possible to configure the passage for compressed air without requiring a large design change. Therefore, the electrically controlled air brake system of the present invention can be manufactured relatively inexpensively.

Further, even if the pedal switch 35 is provided, the depression of the brake pedal 4 is hardly influenced, so that the pedal feeling is almost the same as the pedal feeling in the conventional air brake system. This eliminates the need for adjusting the pedal feeling.

Further, in each of the above-described embodiments, since both the air brake system and the electric control system are two systems, a sufficient fail-safe function can be exerted.

In the above embodiment, the front wheel brake system A is common to the left and right, and the rear wheel brake system B is common to the left and right or independent to the left and right. However, the present invention is not limited to this. Without being limited to this, for example, two systems including a brake system in which the right front wheel and the left rear wheel are common and a brake system in which the left front wheel and the right rear wheel are common, and any other two systems of electric systems It can be applied to a controlled air brake system or an air over hydraulic brake system.

The ABS system and T shown in FIG.
RC system can be installed individually,
It goes without saying that the present invention can also be applied to an electrically controlled air brake system or an air over hydraulic brake system that does not include the relay valve shown in FIG.

[0063]

As is apparent from the above description, according to the electrically controlled air brake system of the present invention, the electromagnetic valve for controlling the compressed air is controlled to be opened and closed by the electronic control unit. Can be operated with almost no response delay, and good responsiveness can be obtained.

Further, according to the present invention, the air brake can be surely actuated even when the solenoid valve is not opened due to the failure of the electric control system, so that the fail safe function is surely exhibited. be able to.

Further, according to the present invention, the conventional brake valve can be used as it is as the brake valve, and a large design change for adding some passages to the passage of the conventional air brake system is not required. A compressed air passage can be configured. Therefore, it is possible to manufacture the electrically controlled air brake system at a relatively low cost.

Further, according to the present invention, since the pedal switch for simply turning on and off is simply provided, it has almost no effect on the depression of the brake pedal. Therefore, the pedal feeling is the pedal in the conventional air brake system. It can be almost the same as feeling. This makes it unnecessary to adjust the pedal feeling.

Further, according to the inventions of claims 2 and 4,
Since both the air brake system and the electric control system have two systems, a sufficient fail-safe function can be exhibited. Further, according to the invention of claim 5, at least one of the anti-skid brake control and the traction control can be performed with good response.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of an electrically controlled air brake system according to the present invention.

FIG. 2 is a circuit diagram similar to FIG. 1, showing another embodiment of the present invention.

FIG. 3 is a circuit diagram similar to FIG. 1, showing still another embodiment of the present invention.

FIG. 4 is a circuit diagram showing an example of a conventional air brake system.

FIG. 5 is a circuit diagram showing an example of a conventional electrically controlled air brake system.

[Explanation of symbols]

1 ... Electric control air brake system, 2 ... Brake pedal, 3 ... Dual brake valve, 3a ... 1st input port,
3b ... 1st output port, 3c ... 2nd input port, 3d ... 2nd output port, 3e ... Discharge port, 4 ... Front wheel side relay valve, 4a ... Control room, 4b ... Input port, 4c ... Output port, 4d ... Vent,
5,7,10,13,15,16,18,22,31,38,4
0,43,46 ... passage, 6 ... rear wheel relay valve, 6a ...
Control room, 6b ... Input port, 6c ... Output port, 6d ... Discharge port,
8, 9 ... Left and right front wheel brake actuators, 11, 12
... left and right rear wheel brake actuators, 14 ... front wheel side air tank, 17 ... rear wheel side air tank, 19 ... front wheel side first
Pressure sensor 20, front wheel side control signal pressure leak prevention valve, 21
... front wheel side one-way valve, 23 ... front wheel side control signal pressure supply valve, 2
4 ... Front wheel side control signal pressure discharge valve, 25 ... Front wheel side second pressure sensor, 26 ... Rear wheel side first pressure sensor, 27 ... Rear wheel side first
Control signal pressure leakage prevention valve 28, rear wheel side first one-way valve, 2
9 ... Rear wheel second control signal pressure leakage prevention valve, 30 ... Rear wheel second
One-way valve, 32 ... Rear wheel side control signal pressure supply valve, 33 ... Rear wheel side control signal pressure discharge valve, 34 ... Rear wheel side second pressure sensor, 3
5 ... Pedal switch, 36 ... First electronic control unit (first E
CU), 37 ... Second electronic control unit (second ECU), 39
... front wheel side brake pressure leakage prevention valve, 41 ... front wheel side brake pressure supply valve, 42 ... front wheel side brake pressure discharge valve, 44 ... rear wheel side first brake pressure leakage prevention valve, 45 ... rear wheel second brake pressure leakage prevention Valve, 47 ... Rear wheel side brake pressure supply valve, 48 ...
Rear wheel side brake pressure discharge valve, 49, 50 ... Left, right front wheel, 5
1, 52 ... left, right front wheel speed sensor, 53, 54 ... left,
Right rear wheel, 55, 56 ... Left and right rear wheel speed sensors

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 15, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

[Figure 5]

Claims (5)

[Claims] 1. A brake pedal having an input port, an output port connectable to the input port, and a discharge port connectable to the output port, wherein the discharge port communicates with the output port when the brake pedal is released. A brake valve that is connected to the input port while the output port is blocked from the exhaust port when stepping on; an air tank that is always connected to the input port and stores compressed air; and a brake actuator that generates a braking force. A control chamber, an input port, an output port connectable to the input port, and an exhaust port connectable to the output port. Normally, the output port is connected to the exhaust port and a control signal is sent to the control chamber. When a pressure is introduced, the output port is disconnected from the exhaust port and connected to the input port, and a relay valve for controlling the supply / discharge of the brake pressure to / from the brake actuator; A first passage connecting the output port of the rake valve and the control chamber of the relay valve;
A second passage connecting the input port of the relay valve and the air tank, a third passage connecting the output port of the relay valve and the brake actuator, the control chamber of the relay valve, and the air tank. A control signal pressure leakage prevention valve which is provided in the first passage and is connected to the first passage, and which is a normally open control signal pressure leakage prevention valve and a control signal pressure leakage prevention valve. When the pressure difference between the upstream side and the downstream side of the valve is a predetermined pressure or more, a one-way valve that allows only the flow of compressed air from the upstream side to the downstream side, and a solenoid valve provided in the fourth passage, A normally closed control signal pressure supply valve, a normally closed control signal pressure discharge valve consisting of a solenoid valve for discharging the control signal pressure of the control chamber of the relay valve, the output port of the brake valve and the control Signal leak A first pressure sensor for detecting the pressure of the first passage between the prevention valve, a second pressure sensor for detecting the pressure of the brake actuator, and a normally open pedal switch that is turned on when the brake pedal is stepped on; An electronic control unit for electrically controlling the brake operation by electrically connecting the control signal pressure leak prevention valve, the control signal pressure supply valve, the control signal pressure discharge valve, the first and second pressure sensors, and the pedal switch. An electrically controlled air brake system characterized by consisting of 2. A first input port, a first output port connectable to the first input port, a second input port, a second output port connectable to the second input port, and the first and second ports. An exhaust port connectable to the output port is provided. When the brake pedal is released, the exhaust port communicates with the first and second output ports, and when the brake pedal is depressed, the first and second output ports are the exhaust port. A dual brake valve that is shut off and connected to the first and second input ports; a first brake system side air tank that is always connected to the first and second input ports and stores compressed air; Which has a first brake system side brake actuator, a control chamber, an input port, an output port connectable to this input port, and an exhaust port connectable to this output port. And control signal pressure to the control room A first brake system-side relay valve that controls the supply and discharge of brake pressure to and from the first brake system-side brake actuator when the output port is cut off from the exhaust port and connected to the input port. A first brake system side first passage connecting the first output port of the brake valve and the control chamber of the first brake system side relay valve; the input port of the first brake system side relay valve; A first brake system side second passage that connects to a first brake system side air tank, and a first brake system side that connects the output port of the first brake system side relay valve and the first brake system side brake actuator. A first passage connecting a third passage, the control chamber of the relay valve on the first brake system side, and the air tank on the first brake system side A fourth passage on the brake system side, a normally open first brake system side control signal pressure leak prevention valve which is provided in the first brake system side first passage, and is composed of an electromagnetic valve, and the first brake system side control signal pressure. When the pressure difference between the upstream side and the downstream side of the first brake system side control signal pressure leakage prevention valve is provided in parallel with the leakage prevention valve and is equal to or more than a predetermined pressure, compressed air from the upstream side to the downstream side is compressed. A first brake system side one-way valve that allows only a flow; a normally closed first brake system side control signal pressure supply valve that is provided in the first brake system side fourth passage and includes an electromagnetic valve; A normally closed first brake system side control signal pressure discharge valve for discharging the control signal pressure of the control chamber of the brake system side relay valve, the first output port of the brake valve and the first brake system side control signal pressure Between the leak prevention valve A first brake system side first pressure sensor that detects the pressure of the first brake system side first passage, a first brake system side second pressure sensor that detects the pressure of the first brake system side brake actuator, and a compression A second brake system side air tank that stores air, a second brake system side brake actuator that generates braking force, a control room, an input port, an output port that can be connected to this input port, and an exhaust port that can be connected to this output port. An outlet is provided, and when the control signal pressure is introduced into the control chamber while the output port is normally connected to the output port, the output port is disconnected from the exhaust port and connected to the input port, A second brake system side relay valve for controlling supply and discharge of brake pressure to and from the second brake system side brake actuator; and the second output of the brake valve. And a second brake system side first passage connecting the control chamber of the second brake system side relay valve, the input port of the second brake system side relay valve and the second brake system side air tank. A second brake system side second passage, a second brake system side third passage connecting the output port of the second brake system side relay valve and the second brake system side brake actuator, and the second brake A second brake system side fourth passage connecting the control chamber of the system side relay valve and the second brake system side air tank, and a second brake system side first passage provided close to the brake valve, Provided in parallel with the normally open first control signal pressure leakage prevention valve on the second brake system side, which is composed of a solenoid valve, and the first control signal pressure leakage prevention valve on the second brake system side. When the pressure difference between the upstream side and the downstream side of the second control signal pressure leakage prevention valve on the second brake system side is equal to or more than a predetermined pressure, only the flow of compressed air from the upstream side to the downstream side is allowed. A first one-way valve on the second brake system side, and a normally open second brake system side first solenoid valve provided on the second passage on the second brake system side close to the relay valve on the second brake system side. Two control signal pressure leakage prevention valves are provided in parallel with the second brake system side second control signal pressure leakage prevention valve, and upstream and downstream sides of the second brake system side second control signal pressure leakage prevention valve. Provided in the second brake system side fourth one-way valve that allows only the flow of compressed air from the upstream side to the downstream side when the pressure difference between the two is greater than or equal to a predetermined pressure, and the second brake system side fourth passage. Normally closed second brake system consisting of a solenoid valve A control signal pressure supply valve, a normally closed second brake system side control signal pressure discharge valve for discharging the control signal pressure of the control chamber of the second brake system side relay valve, and the second output port of the brake valve And a second brake system side first control signal pressure leakage prevention valve between the second brake system side first passage for detecting the pressure in the second brake system side first passage, and the second brake system side A second brake system side second pressure sensor for detecting the pressure of the brake actuator, the first brake system side control signal pressure leak prevention valve, the first brake system side control signal pressure supply valve, the first brake system side control A signal pressure discharge valve, the first brake system side first and second pressure sensors, the second brake system side first pressure sensor, a second brake system side first control signal pressure leak prevention valve, and the valve. First electronic control unit electrically controlling a brake operation of the first brake system by electrically connecting a switch to the second brake system, a second control signal of the second brake system, a pressure leakage prevention valve, and a control signal of the second brake system. The pressure supply valve, the second control signal pressure discharge valve on the second brake system side, and the second pressure sensor on the second brake system side are electrically connected to each other and electrically connected to the first electronic control unit. An electrically controlled air brake system comprising a second electronic control unit for controlling brake operation of a two-brake system. 3. A brake pedal having an input port, an output port connectable to the input port, and a discharge port connectable to the output port, wherein the discharge port communicates with the output port when the brake pedal is released. A brake valve that is connected to the input port while the output port is blocked from the exhaust port when stepping on; an air tank that is always connected to the input port and stores compressed air; and a brake actuator that generates a braking force. A first passage connecting the output port of the brake valve and the brake actuator, a second passage connecting the brake actuator and the air tank, and a normally open solenoid valve provided in the first passage. Of the brake pressure leakage prevention valve and the brake pressure leakage prevention valve are provided in parallel, and the pressure difference between the upstream side and the downstream side of the brake pressure leakage prevention valve is A one-way valve that allows only the flow of compressed air from the upstream side to the downstream side when the pressure is equal to or higher than a predetermined pressure; a normally-closed brake pressure supply valve that is provided in the second passage and includes a solenoid valve; A normally-closed brake pressure discharge valve that is an electromagnetic valve that discharges the brake pressure of a brake actuator, and a first pressure detecting means for detecting the pressure in the first passage between the output port of the brake valve and the brake pressure leakage prevention valve. A pressure sensor, a second pressure sensor that detects the pressure of the brake actuator, a normally-open pedal switch that is turned on when the brake pedal is depressed, the brake pressure leakage prevention valve, the brake pressure supply valve, and the brake pressure discharge. A valve, the first and second pressure sensors, and an electronic control unit that electrically connects the pedal switch to control brake operation. Electrically controlled air brake system. 4. A first input port, a first output port connectable to the first input port, a second input port, a second output port connectable to the second input port, and the first and second ports. An exhaust port connectable to the output port is provided. When the brake pedal is released, the exhaust port communicates with the first and second output ports, and when the brake pedal is depressed, the first and second output ports are the exhaust port. A dual brake valve that is shut off and connected to the first and second input ports; a first brake system side air tank that is always connected to the first and second input ports and stores compressed air; A first brake system side brake actuator, a first brake system side first passage connecting the first output port of the brake valve and the first brake system side brake actuator, and the first brake system side Brae A first brake system side second passage that connects an actuator and the first brake system side air tank, and a normally open first brake system side brake pressure that is provided in the first brake system side first passage and includes an electromagnetic valve When the leakage prevention valve and the first brake system side brake pressure leakage prevention valve are provided in parallel, and the pressure difference between the upstream side and the downstream side of the first brake system side brake pressure leakage prevention valve is a predetermined pressure or more, A first brake system side one-way valve that allows only the flow of compressed air from the upstream side to the downstream side, and a normally closed first brake that is provided in the first brake system side second passage and includes an electromagnetic valve A system side brake pressure supply valve, a normally closed first brake system side brake pressure discharge valve for discharging the brake pressure of the first brake system side brake actuator, and the brake valve described above. A first brake system side first pressure sensor for detecting a pressure in the first brake system side first passage between the first output port and the first brake system side brake pressure leakage prevention valve; and the first brake system side A first brake system side second pressure sensor that detects the pressure of the brake actuator, a second brake system side air tank that stores compressed air, a second brake system side brake actuator that generates a braking force, and the brake valve described above. A second brake system side first passage that connects a second output port and the second brake system side brake actuator, and a second brake that connects the second brake system side brake actuator and the second brake system side air tank. A system side second passage and a second brake system side first passage are provided close to the brake valve. , A normally-open second brake system side first brake pressure leakage prevention valve formed of an electromagnetic valve, and the second brake system side first brake pressure leakage prevention valve provided in parallel, and the second brake system side first brake A second brake system side first one-way valve that allows only the flow of compressed air from the upstream side to the downstream side when the pressure difference between the upstream side and the downstream side of the pressure leakage prevention valve is a predetermined pressure or more; A normally open second brake system side second brake pressure leakage prevention valve, which is provided in the second brake system side first passage in proximity to the second brake system side brake actuator, and which is an electromagnetic valve; When the pressure difference between the upstream side and the downstream side of the second brake system side second brake pressure leakage prevention valve is equal to or more than a predetermined pressure, it is provided in parallel with the system side second brake pressure leakage prevention valve. Downstream compression A second brake system-side second one-way valve that allows only air flow; a normally closed second brake system-side brake pressure supply valve that is provided in the second brake system-side second passage and includes an electromagnetic valve; A normally closed second brake system side brake pressure discharge valve for discharging the brake pressure of the second brake system side brake actuator, the second output port of the brake valve, and the second brake system side first brake pressure leakage prevention A second brake system side first pressure sensor that detects a pressure in the second brake system side first passage between the valve and a second brake system side second pressure sensor that detects a pressure in the second brake system side brake actuator. A pressure sensor, the first brake system side brake pressure leakage prevention valve, the first brake system side brake pressure supply valve, the first brake system side brake pressure discharge valve, the front The first brake system side first and second pressure sensors, the second brake system side first pressure sensor, the second brake system side first brake pressure leakage prevention valve, and the pedal switch are electrically connected to each other, and A first electronic control unit for controlling the brake operation of a first brake system, the second brake system side second brake pressure leakage prevention valve, the second brake system side brake pressure supply valve, the second brake system side brake pressure A second electronic control in which the discharge valve and the second pressure sensor on the second brake system side are electrically connected and are electrically connected to the first electronic control unit to control the brake operation of the second brake system. An electrically controlled air brake system comprising a device. 5. A first brake system side wheel speed sensor electrically connected to the first electronic control unit for detecting a wheel speed of a wheel corresponding to the first brake system, and the second electronic control unit. A second brake system side wheel speed sensor that is electrically connected and detects a wheel speed of a wheel corresponding to the second brake system is provided, and the first electronic control unit is provided with an anti-drive system in the first brake system. The at least one of skid brake control and traction control is performed, and the second electronic control unit performs at least one of antiskid brake control and traction control in the second brake system. Electric control air brake system.