JPH11139301A - Parking brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release a parking brake easily when air failure occurs. SOLUTION: This parking brake device is equipped with an air tank 11, spring brake chambers 12 which immobilize the parking brake by filling cylinder chambers 12e with high-pressure air, and a parking brake control valve 13 which charges high-pressure air into the cylinder chambers 12e when it is turned off and discharges the high-pressure air to activate the parking brake when it is turned on. A connecting pipe 21 connecting the air tank 11 and the cylinder chambers 12e, a normally-closed solenoid valve 22 which is interposed in the connecting pipe 21 and made of a structure to allow the high-pressure air in the air tank 11 to be supplied into the cylinder chambers 12e when the solenoid valve 22 opens, a pressure sensor 23 for detecting the air pressure of the cylinder chambers 12e, and a controller 24 which controls the solenoid valve 22 so that is opens when the parking brake control valve 13 is in OFF position and further, when the pressure detected by the pressure sensor 23 is below a prescribed level, are to be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parking brake device for disabling a parking brake by charging high pressure air into a cylinder chamber of a spring brake chamber from a state where the parking brake is operated.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
There is known a parking brake device including spring brake chambers 2 and 2 for disabling a parking brake by filling e with high-pressure air. In addition to the spring brake chambers 2 and 2, this device includes an air tank 1, a parking brake control valve 3 connected to the air tank 1, and wheels 5 connected to push rods 2 c and 2 c of the spring brake chambers 2 and 2. 5 is provided with wheel parking brake mechanisms 4 and 4 for applying a parking brake. A relay valve 6 is interposed between the parking brake control valve 3 and the spring brake chambers 2 and 2,
The parking brake control valve 3 is connected to a control input port 6 a of a relay valve 6, and the air tank 1 is connected to a working air input port 6 b. Inside the spring brake chamber 2 is a diaphragm 2
b and a compression spring 2a compressed by air pressure through the diaphragm 2b.
The output port 6c of the relay valve 6 is communicatively connected to e.

In this conventional parking brake device,
A state in which the cylinder chamber 2e is not filled with high-pressure air, that is, a parking state in which the air tank 1 is not filled with high-pressure air, or a state in which the parking brake control valve 3 is turned on and the high-pressure air is discharged from the cylinder chamber 2e to the outside via the relay valve 6. In the stopped state where the vehicle is discharged, the compression spring 2a urges the diaphragm 2b in a direction to retract the push rod 2c, and the push rods 2c, 2c are retracted, so that the parking brake is operated via the parking brake mechanisms 4, 4. In order to run the vehicle, the parking brake control valve 3 is turned off, and the cylinder chamber 2 e is filled with high-pressure air from the air tank 1 via the relay valve 6. Then, the high-pressure air filled in the cylinder chamber 2e overcomes the urging force of the compression spring 2a to move the diaphragm 2b in a direction in which the push rods 2c, 2c project, and release the parking brake by the parking brake mechanisms 4, 4. It has become.

[0004]

However, in the above-mentioned conventional parking brake device, air is lost at the upstream side of the relay valve 6, such as blockage due to deformation or the like caused by an external force of the air pipe at the upstream side of the relay valve 6. Occurs, even if the parking brake control valve 3 is turned off, the cylinder chamber 2e cannot be filled with high-pressure air from the air tank 1, and the parking brake cannot be released. In order to solve this problem, a lock nut 8 and a rotation nut 7 are provided in the conventional spring brake chamber 2. The lock nut 8 is loosened and the rotation nut 7 is rotated to compress the internal compression spring 2 a and push it. The rod 2c can be made to protrude. However, since these spring brake chambers 2 and 2 are usually arranged inside the chassis frame of the vehicle or at the rear axle, etc., to perform such work, they must sink under the vehicle. Is extremely difficult. An object of the present invention is to fill a cylinder chamber with high-pressure air from an air tank without sneaking into the lower side of a vehicle when an air failure occurs upstream of a relay valve, and to easily release a parking brake. It is to provide a parking brake device.

[0005]

The invention according to claim 1 is
As shown in FIG. 1, an air tank 1 in which high-pressure air is stored
1, a spring brake chamber 12 for disabling the parking brake by filling the cylinder chamber 12e with high-pressure air, and a high-pressure air in the air tank 11 is supplied to the cylinder chamber 12e by an OFF operation and a high pressure of the cylinder chamber 12e is supplied by an ON operation. Parking brake control valve 1 that discharges air to activate the parking brake
3 is an improvement of the parking brake device provided with the above. Its characteristic configuration is that the air tank 11 and the cylinder chamber 12e
And a normally-closed electromagnetic valve 22 which is provided in the connection pipe 21 so as to supply high-pressure air from the air tank 11 to the cylinder chamber 12e.
And a pressure sensor 2 for detecting an air pressure in the cylinder chamber 12e.
3 and a controller 24 for controlling the solenoid valve 23 to open when the parking brake control valve 13 is off and the pressure detected by the pressure sensor 23 is equal to or lower than a predetermined value.

[0006] When air is lost upstream of the relay valve 16 and the parking brake control valve 13 is turned off, high-pressure air is supplied from the relay valve 16 to the cylinder chamber 12e. Instead, the pressure sensor 23 detects that the air pressure in the cylinder chamber 12e is equal to or lower than a predetermined value, and the controller 24 controls the solenoid valve 22 to open. When the solenoid valve 22 is opened, the air tank 11 and the cylinder chamber 12e are connected and connected, and high-pressure air is directly supplied from the air tank 11 to the cylinder chamber 12e via the connection pipe 21 to release the parking brake.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIG. 1, the parking brake device 10 includes an air tank 11 storing high-pressure air, a spring brake chamber 12, and a parking brake control valve 13. As shown in FIG. 3, the spring brake chamber 12 is supplied with a push rod 12c having a diaphragm 12b which is pulled in a direction to operate the parking brake by a compression spring 12a, and high pressure air for releasing the parking brake from an air port 12d. Push rod 12c
And a cylinder chamber 12e for pushing the diaphragm 12b in the direction to release the parking brake. A wheel parking brake mechanism 14 (FIG. 1) is connected to the push rod 12c.
Is the push rod 1 in the normal state by the compression spring 12a.
2c is immersed and the parking brake is activated,
When high-pressure air for releasing the parking brake is supplied from the airport 12d to the cylinder chamber 12e, the parking brake is deactivated.

Returning to FIG. 1, the parking brake control valve 13 includes an air tank 11 and a relay valve 16.
Is connected to the control air input port 16a, and the air tank 11 is connected to the working air input port 16b of the relay valve 16. An output port 16 c of the relay valve 16 is connected to a cylinder chamber 12 e of the spring brake chamber 12. When the parking brake control valve 13 is not operated, that is, when the parking brake control valve 13 is off, the air for the control input is relayed from the air tank 11 through the one air pipe 17a via the parking brake control valve 13. The air flows into the control input port 16a of the valve 16, presses a diaphragm (not shown) provided inside the relay valve 16, and guides the high-pressure air in the air tank 11 from the input port 16b to the output port 16c to cause the cylinder chamber 12e of the spring brake chamber 12 to move.
To supply.

On the other hand, when the parking brake is operated by operating the parking brake lever 13a of the parking brake control valve 13, that is, when the parking brake control valve 13 is turned on, the parking brake control valve 13 is connected to the air pipe 17a. The passage is closed, and the air in the air pipe 17b between the parking brake control valve 13 and the relay valve 16 is exhausted from the exhaust port 13b of the parking brake control valve 13. By this exhaust, a diaphragm (not shown) provided inside the relay valve 16 closes the input port 16b, and discharges the high-pressure air in the cylinder chamber 12e from the exhaust port 16d to operate the parking brake.

The characteristic configuration of the present invention is the air tank 11
Pipe 21 for communicating and connecting the cylinder chamber 12e with the cylinder chamber 12e; a solenoid valve 22 interposed in the connection pipe 21;
It is provided with a pressure sensor 23 for detecting the air pressure 2e and a controller 24. The connection pipe 21 in the present embodiment has one end connected to the air tank 11 and the other end connected to the output port 16 c of the relay valve 16 and the cylinder chamber 12.
e is connected via a double check valve 26 to an air pipe 17c that communicates with e. That is, the first input port 2
6a is connected to the output port 16c of the relay valve 16,
By connecting the discharge port 26c to the cylinder chamber 12e, the double check valve 26 is connected to the air pipe 17c connecting the relay valve 16 and the cylinder chamber 12e.
Intervene. By connecting the other end of the connection pipe 21 to the second input port 26b of the double check valve 26 interposed in this way, the connection pipe 21 is configured to connect and connect the air tank 11 and the cylinder chamber 12e. .

A solenoid valve 22 interposed in the connection pipe 21 is a three-port two-position switching valve, and is a normally-closed solenoid valve that shuts off the flow of air from the air tank 11 in the connection pipe 21 in a normal state. 22 and double check valve 2
The connection pipe 21 on the sixth side is configured to communicate with the atmosphere.
The pressure sensor 23 for detecting the air pressure in the cylinder chamber 12e is provided in the air pipe 17c downstream of the connection point to which the other end of the connection pipe 21 is connected. Room 12e
It is configured to detect the air pressure of the air.

A detection output of the pressure sensor 23 is connected to a controller 24, and a detection output of the parking brake control valve 13 is further connected to the controller 24 so that an on state or an off state of the parking brake control valve 13 can be detected. Is done. The control output of the controller 24 is connected to the solenoid valve 22 and the alarm lamp 26, and the controller 24 operates when the parking brake control valve 13 is off and the pressure sensor 2
The valve is opened when the pressure detected in step 3 is equal to or lower than a predetermined value.
Solenoid valve 2 so as to connect the cylinder chamber 12e with the cylinder chamber 12e.
2 and the alarm lamp 26 is turned on.

The operation of the parking brake device configured as described above will be described. When the control lever 13a is operated to turn on the parking brake control valve 13 and the high pressure air is discharged from the cylinder chamber 12e to the outside via the exhaust port 16d of the relay valve 16, the cylinder chamber 12e is filled with the high pressure air. For this reason, the diaphragm 12b is urged by the compression spring 12a, the push rod 12c is retracted, and the parking brake operates via the parking brake mechanism 14. In this case, as shown in FIG. 1, the controller 24 detects that the parking brake control valve 13 is in the on state and maintains the solenoid valve 22 in the closed state. The operation state of the parking brake is maintained without being supplied to the cylinder chamber 12e via the cylinder chamber 12e.

In order to make the vehicle travel from this state, the parking brake control valve 13 is turned off, and high pressure air is charged from the air tank 11 into the cylinder chamber 12e from the output port 16c of the relay valve 16 via the double check valve 26. . In the double check valve 26, the valve body 26d closes the second input port 26b by the pressure of the air, and the first input port 26a and the discharge port 26c communicate with each other. Therefore, the high-pressure air from the air tank 11 is filled into the cylinder chamber 12e without the high-pressure air leaking from the second input port 26b by the valve element 26d,
The push rod 12 overcomes the urging force of the compression spring 12a.
The parking brake by the parking brake mechanism 14 is released by moving the diaphragm 12b in the direction in which c projects. In a normal state in which no air failure occurs upstream of the relay valve 16, the cylinder chamber 12e
Is filled with high-pressure air from the air tank 11, the pressure sensor 23 detects that the air pressure in the cylinder chamber 12e is equal to or higher than a predetermined value, and the controller 24 properly releases the parking brake. Is kept closed.

When air is lost upstream of the relay valve 16 and the parking brake control valve 13 is turned off, high-pressure air is supplied from the relay valve 16 to the cylinder chamber 12e. And the parking brake cannot be released.
In this case, the pressure sensor 23 detects that the air pressure in the cylinder chamber 12e is equal to or lower than a predetermined value, and the controller 24 supplies high-pressure air to the cylinder chamber 12e even though the parking brake control valve 13 is off. It is controlled that the solenoid valve 22 is opened as shown in FIG.

When the solenoid valve 22 is opened, the air tank 11
The high-pressure air from the valve passes through the solenoid valve 22 to move the valve element 26d of the double check valve 26, so that the first input port 2
6a is closed, and the second input port 26b is communicated with the discharge port 26c. For this reason, the air tank 11 and the cylinder chamber 12e are connected and connected, and the moved valve element 26
As a result, the high-pressure air from the air tank 11 is directly supplied to the cylinder chamber 12e through the connection pipe 21 as shown by a solid arrow without leaking the high-pressure air from the first input port 26a. The high-pressure air supplied to the cylinder chamber 12e overcomes the urging force of the compression spring 12a and
The parking brake by the parking brake mechanism 14 is released by moving the diaphragm 12b in the direction in which c projects. At this time, the controller 24 turns on the alarm lamp 26 at the same time, and the driver who notices the lighting of the alarm lamp 26 can confirm that an air failure has occurred upstream of the relay valve 16.

FIG. 4 shows another embodiment of the present invention. In the drawing, the same reference numerals as those in the above-described embodiment indicate the same parts, and the description thereof will not be repeated. The vehicle according to the present embodiment is provided with a tire pressure adjusting device 31 that automatically adjusts the air pressure of the tire in addition to the parking brake device 10. One end of the tire pressure adjusting device 31 is
, And the other end thereof has an air flow passage 33 connected to the inside of the tire, and tire pressure valves 32, 32 are provided near the tire in the air flow passage 33. Tire pressure valve 3
2 and 32 are controlled by a tire pressure controller (not shown). By equipping the vehicle with the tire pressure adjusting device 31, the adjustment of the tire air pressure, which was conventionally performed by a driver who got off the vehicle at a specific place such as a gas station by injecting or extracting air from a tire valve,
A tire pressure controller (not shown) controls the tire pressure valves 32 and 32 to guide high-pressure air from the air tank 11 into the tire through the air flow path 33 or shuts off the air flow path 33 to release the air from the inside of the tire. The air pressure of the tire can be increased or decreased by communicating with the tire.

A characteristic configuration of the present embodiment is that one end of a connection pipe 21 is connected to an air flow path 33 between the tire pressure valves 32 and 32 and the air tank 11. The high pressure air having the same pressure as the air stored in the air tank 11 always exists in the air flow path 33 between the tire pressure valves 32 and 32 and the air tank 11.
Is configured to connect and connect the air tank 11 and the cylinder chamber 12e through a part of the air flow path 33 of the tire pressure adjusting device 31. The operation of the parking brake device configured as described above is the same as that of the above-described embodiment, and a repeated description will be omitted.

[0019]

As described above, according to the present invention, the connection pipe for communicating and connecting the air tank and the cylinder chamber, and the high pressure air of the air tank is interposed in the connection pipe and opened to open the cylinder chamber. A normally-closed solenoid valve that can be supplied, a pressure sensor that detects the air pressure in the cylinder chamber, and a valve that opens when the parking brake control valve is off and the detected pressure of the pressure sensor is equal to or lower than a predetermined value. And the controller for controlling the solenoid valve as described above, when the air failure occurs upstream of the relay valve and the parking brake control valve is turned off, the pressure sensor Upon detecting that the air pressure in the chamber is equal to or lower than a predetermined value, the controller controls the solenoid valve to open. As a result, the air tank and the cylinder chamber are connected and connected, and high-pressure air is directly supplied from the air tank to the cylinder chamber via the connection pipe to release the parking brake. Therefore, even if air failure occurs upstream of the relay valve, the cylinder chamber can be filled with high-pressure air from the air tank without sneaking under the vehicle, and the parking brake can be easily released.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a parking brake device of the present invention.

FIG. 2 is a view corresponding to FIG. 1 and shows a state in which a controller controls to open an electromagnetic valve.

FIG. 3 is a side view showing the internal structure of the spring brake chamber.

FIG. 4 is a configuration diagram showing another parking brake device of the present invention.

FIG. 5 is a configuration diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

 11 Air tank 12 Spring brake chamber 12e Cylinder chamber 13 Control valve 21 Connection pipe 22 Solenoid valve 23 Pressure sensor 24 Controller

Claims (1)

[Claims] 1. An air tank storing high-pressure air.
And a spring brake chamber (12) for disabling the parking brake by filling the cylinder chamber (12e) with high-pressure air, and supplying high-pressure air from the air tank (11) to the cylinder chamber (12e) by an off operation. A parking brake control valve (13) for operating a parking brake by discharging high-pressure air from the cylinder chamber (12e) by a turning-on operation, wherein the air tank (11) and the cylinder chamber (12e) are provided. A connecting pipe (21) that communicates with the connecting pipe, and a valve that is interposed in the connecting pipe (21) and is capable of supplying high-pressure air from the air tank (11) to the cylinder chamber (12e) by opening a valve. A closed solenoid valve (22) and a pressure sensor (2) for detecting air pressure in the cylinder chamber (12e).
3) a controller that controls the solenoid valve (23) to open when the parking brake control valve (13) is in an off state and the pressure detected by the pressure sensor (23) is equal to or less than a predetermined value. 24) A parking brake device comprising: