JPH0740809A - Spring brake device - Google Patents

Abstract

PURPOSE:To increase safety by preventing a spring brake from being released even if the braked condition of the spring brake is operated so that it is released when a driver is apart from a driver's seat CONSTITUTION:A spring brake device is provided with a spring brake chamber 1 to hold a spring 1b in pressed state when an air chamber 1a is in pneumatic condition, a mechanical means to set a brake shoe 2 in braked state by a releasing force of a spring when air pressure is eliminated, and a solenoid valve 4 (control valve) to release air pressure by providing air pressure into the air chamber when a vehicle is running. Then the solenoid valve is connected so that air pressure is released when an exciting current is shut off, a switch 5 is provided in an exciting current line at a position where it can be operated outside the vehicle, and the exciting current is shut off when the switch 5 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used by being installed in an automobile. The invention is particularly suitable for equipping buses. The present invention is
In addition to the service brake operated by the brake pedal, the present invention relates to improvement of a spring brake device equipped for parking and the like.

[0002]

2. Description of the Related Art A spring brake device is a brake device equipped especially in a large automobile as an emergency or parking brake device when the air pressure (or hydraulic pressure) of a service brake is lowered. Conventional spring / brake devices often use their brake shoes in common with service brakes.

A conventional spring brake device has a spring brake chamber containing a strong spring, and when the air chamber of the spring brake chamber has air pressure, the spring is in a pressed state. When the air pressure is released, the push rod is displaced by the spring force. The push rod is connected to a piston that drives the brake shoe of the service brake, and when the air pressure in the spring brake chamber is released, the brake brake is actuated with or without the service brake drive pressure. It is configured to drive the shoe to bring it into a braking state.

In such a spring / brake device, a control valve for controlling the air pressure in the spring / brake chamber is provided, and the control valve automatically applies the air pressure when the vehicle can run, so that the driver's seat can be manually operated. It is configured so that the air pressure can be released by operation to bring it into a braking state. In conventional devices, this control valve is a pneumatic relay valve used in many devices, and is configured to give control pressure to this relay valve via a manually operated valve provided in the driver's seat. .

[0005]

In the spring / brake device having such a structure, for example, when the driver temporarily needs to get out of the vehicle, the spring / brake device is kept in a braking state, so that The vehicle can be prevented from inadvertently starting, but the braking state can be easily released by a passenger mischieving the manually operated valve. This operation requires less force than the operation to release the parking brake, so it is easier to operate.

The present invention provides a device with improved safety by preventing the driver from releasing the braking state of the spring brake when the driver is away from the seat. With the goal.

[0007]

SUMMARY OF THE INVENTION The present invention provides a spring
The control valve of the brake device is an electromagnetic valve, and is connected so as to be in a non-braking state when an exciting current of the electromagnetic valve is flowing and to be in a braking state when the exciting current is cut off. Further, two or more open / close switches are provided in series in the passage of the exciting current, and one of them is arranged at a position where it can be operated outside the vehicle.

That is, according to the present invention, a spring brake chamber that holds a spring in a pressed state when air pressure is present in the air chamber, and a brake shoe that is released by the spring when the air pressure disappears. In a spring-brake device including a mechanical means for setting a braking state and a control valve for releasing air pressure by applying air pressure to the air chamber when the vehicle is traveling, the control valve is a solenoid valve, The solenoid valve is connected so as to release the air pressure when the exciting current is cut off, and an opening / closing switch arranged at a position where it can be operated outside the vehicle is provided in the passage of the exciting current.

2 arranged in series in the exciting current path
The individual opening / closing switches, the first of which is arranged in the driver's seat and the second of which is arranged in a position where it can be operated outside the vehicle, and the second of the opening / closing switches is the outside-of-vehicle operation switch of the entry / exit door of the vehicle It is desirable to be linked.

Further, the opening / closing switch arranged at a position where it can be operated outside the vehicle is interlocked with the automatic door opening / closing switch, and is provided with a relay valve on the air pressure supply side of the solenoid valve, and controls the relay valve. A control valve can be provided in the pneumatic passage, and the operating end of the control valve can be placed in the driver's seat.

[0011]

Operation: Even if the driver leaves the driver's seat, the spring / brake device can be brought into the braking state by operating the open / close switch outside the vehicle. Since the open / close switches are connected in series, if one of them is in a cutoff state, the exciting current of the solenoid valve is in a cutoff state. Even if the opening / closing switch of the spring / brake device is operated in the driver's seat, or if the operator forgets to operate the opening / closing switch of the spring / brake device when leaving the driver's seat, the spring / open switch outside the vehicle can be operated to -The braking device can be maintained in a braking state.

By interlocking the opening / closing switch on the outside of the vehicle with the switch provided conventionally for opening / closing the door for getting on / off from the outside of the vehicle, the spring / brake is automatically applied when the door for getting on / off is closed from the outside of the vehicle. The device goes into braking.

Further, an opening / closing switch arranged at a position where it can be operated outside the vehicle is interlocked with the automatic door opening / closing switch, and a relay valve is provided on the pneumatic side of the solenoid valve, and the relay valve controls the passage of the control pneumatic pressure. -Even when a valve is provided, the exciting current to the solenoid valve is cut off if the open / close switch outside the vehicle is operated. Therefore, even if the control valve is intentionally operated in the driver's seat, air pressure is not supplied to the air chamber of the spring brake chamber, and the braking state by the spring can be maintained.

[0014]

Embodiments of the present invention will now be described with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention, and FIG. 2 is a diagram showing a layout position of an on-vehicle outside opening / closing switch in the first embodiment of the present invention.

In the first embodiment of the present invention, the spring brake chamber 1 holds the spring 1b in a pressed state when the air chamber 1a has air pressure, and the force released by the spring 1b when the air pressure disappears. A mechanical means 3 for setting the brake shoe 2 in a braking state by means of a solenoid valve 4, and a solenoid valve 4 used as a control valve for applying an air pressure to the air chamber 1a during operation of the vehicle to release the air pressure by an operation.
Further, as a feature of the present invention, the solenoid valve 4 is connected so as to release the air pressure when the exciting current is cut off, and two opening / closing switches are provided in the passage of the exciting current, one of which is The driver's seat switch 5 is arranged in the driver's seat, and the other one is arranged as a vehicle exterior switch 6 at a position where it can be operated outside the vehicle. The vehicle exterior switch 6 is configured to interlock with a vehicle exterior device switch of a vehicle entrance / exit door, is arranged inside a bumper 7 as shown in FIG. 2, and is hidden by a lid 8 so as not to be operated unintentionally.

Further, the above-mentioned mechanical means 3 includes a spring
Brake chamber 1 chamber side push rod 1
An idler lever 3a which is rotated by the movement of c, a cylinder side push rod 3b which is moved according to the rotation of the idler lever 3a, and a tip portion which is fixed to the cylinder side push rod 3b and has a conical shape. The wedge 3c, the wheel cylinder 3d slidably installed in the wedge 3c, and the ball 3f slidably installed in the wheel cylinder 3d and arranged on the conical surface of the wedge 3c. And two pistons 3e that receive the opening / closing operation and transmit the operation to the brake shoe 2.

Next, the operation of the first embodiment of the present invention thus constructed will be described.

Normally, the driver's seat switch 5 and the vehicle exterior switch 6 are closed when the vehicle is running or temporarily stopped, so that the solenoid valve 4 is supplied with power from the battery 11. The solenoid valve 4 supplies air pressure from the spring / brake tank 12 to the air chamber 1a of the spring / brake chamber 1 by supplying power. In the example shown in FIG. 1, the chamber-side push rod 1c receiving the air pressure is pushed downward to stop the spring 1b in a compressed state.

By the movement of the chamber-side push rod 1c, the idler lever 3a rotates about the fulcrum P, and the wedge 3c connected to the cylinder-side push rod 3b is pulled out. When the wedge 3c is pulled out,
The outer diameter of the conical surface on which the ball 3f is arranged becomes smaller, and the two pistons 3e in contact with the ball 3f move inward. Along with this movement, the brake shoes 2 each receiving the urging force of the return spring (not shown) move inward and the braking is released. In this state, when the service brake is operated and hydraulic pressure is applied to the inlet 3g, the piston 3e is pushed open and the brake shoe 2 pushes the brake drum (not shown).

When the vehicle stops and the driver opens the driver's seat switch 5, the power supplied from the battery 11 to the solenoid valve 4 is shut off, and the solenoid valve 4 discharges the air in the air chamber 1a to the outside. To do. With the release of the air pressure, the spring 1b expands to push back the chamber side push rod 1c and rotate the idler lever 3a. The rotation of the idler lever 3a pushes the cylinder side push rod 3b into the wheel cylinder 3d to move the connected wedge 3c to the piston 3e side.
By this movement, the wedge 3c with which the ball 3f is in contact
The outer diameter of the conical surface becomes larger, and the pistons 3e are pushed outward, respectively, and the brake shoe 2 opens and enters the braking state.

When the vehicle is stopped and the driver goes out of the vehicle, the driver seat switch 5 is opened. As a result, the spring brake is in a braking state. However, it is possible that this operation is forgotten, or that the user is in the closed state for other unexpected reasons even though it was in the open state. If there is such a concern, even if the driver leaves the driver's seat, by opening the lid 8 shown in FIG. Is connected in series, so battery 1
No power is supplied from 1 to the solenoid valve 4, and air pressure is not supplied to the air chamber 1a of the spring brake chamber 1 as described above, so that the braking state can be maintained.

The exterior switch 6 is a door 9 for getting on and off the vehicle.
Since it is interlocked with the operation switch outside the vehicle, when the passenger door is closed from outside the vehicle, the spring / brake automatically operates and the braking state is maintained.

(Second Embodiment) FIG. 3 is a diagram showing the configuration of the second embodiment of the present invention. In the second embodiment of the present invention, the air chamber 21
Spring brake chamber 21 for holding spring 21b in a pressed state when there is air pressure in a
Mechanical means 31 for setting the brake shoe 2 in a braking state by the force released by the spring 21b when the air pressure disappears, and an electromagnetic valve for applying air pressure to the air chamber 21a when the vehicle is running to release the air pressure by an operation. 4, a relay valve 22 provided on the air pressure supply side of the solenoid valve 4, a control valve 23 provided in a passage for the control air pressure of the relay valve 22 and having its operating end located in the driver's seat, The vehicle includes an exterior switch 6 arranged at a position outside the vehicle where it can be operated and configured to interlock with an exterior operation switch of a vehicle door.

The mechanical means 31 also comprises a first push rod 21c in the spring brake chamber 21.
And a second push rod 21d and a camshaft 10 rotatably connected to the second push rod 21d.

Next, the operation of the second embodiment of the present invention thus constructed will be described.

When the vehicle is running or temporarily stopped, the exterior switch 6 is closed and the control valve 23 is open. Therefore, the current from the battery 11 is supplied to the solenoid valve 4 and the solenoid valve 4 is opened to the relay valve 2
Air pressure from 2 is spring brake chamber 21
Is provided to the air chamber 21a. The first push rod 21c receiving the air pressure is pushed downward to compress the spring 21b. In this state, the brake is released.

With the downward movement of the first push rod 21c, the second push rod 21d descends, and the tip portion of the brake shoe 2 is biased by a spring (not shown) to the camshaft. It moves to the concave portion 10 and the braking is released.

When the vehicle is stopped and the control valve 23 provided in the driver's seat is closed by the driver, the relay
The supply of air pressure to the valve 22 is stopped, the relay valve 22 closes the air pressure supply path to the solenoid valve 4, and opens the exhaust port to electromagnetically transfer the air in the air chamber 21a of the spring brake chamber 21. Discharge via valve 4. With the release of this air pressure, the spring 21b extends and pushes up the first push rod 21c and the second push rod 21d. Due to this pushing up, the camshaft 10 rotates to push the tip of the brake shoe 2 open and bring it into a braking state.

Thus, when the driver operates the control valve 23 to close it, the spring 21b brings about a braking state, but when the driver leaves the vehicle, he or she forgets the operation or closes it, but the passengers Therefore, the vehicle exterior switch 6 is operated to bring the vehicle into the open state in order to prevent such a situation. When the switch 6 outside the vehicle is in the open state, the voltage of the battery 11 is not added to the solenoid valve 4, and the solenoid valve 4 is relayed.
Stop the air pressure supply from the valve 22 and
The air pressure in the air chamber 21a of the brake chamber 21 is released to the outside.

The release of the air pressure causes the spring 21b to expand and push up the camshaft 10 to bring it into a braking state, as described above. This allows control valve 2
Even if the operation of No. 3 is forgotten or the passenger performs an operation of opening it, the air pressure is not supplied from the solenoid valve 4 to the air chamber 21a, and the braking state is maintained. Exterior switch 6
Since it is configured to interlock with the outside operation switch of the entrance / exit door, when the outside switch 6 is opened and the spring / brake device is set to the braking state, the entrance / exit door is automatically closed, and passengers are overlooked. You can avoid getting off.

When the driver's vehicle gets in the vehicle, the battery 1 is stored in the solenoid valve 4 by closing the switch 6 outside the vehicle.
A current of 1 is supplied and the solenoid valve 4 opens the passage to the spring brake chamber 21. Next, when the control valve 23 is operated to the open state, the air pressure from the spring brake tank 12 is supplied to the relay valve 22, and the relay valve 22 closes the discharge port and the air pressure supply port to the solenoid valve 4. To open.
As a result, air pressure is supplied to the air chamber 21a of the spring / brake chamber 21, and the spring 21b is pushed down to release the braking state.

In the conventional device, a relay valve is provided as a control valve for controlling the air pressure in the spring brake chamber, and the relay valve is provided with a control pressure via a manual operation valve provided in the driver's seat. Therefore, the second embodiment of the present invention can be realized by changing only the solenoid valve among the main components shown by the chain double-dashed line in FIG.

[0034]

As described above, according to the present invention, when the driver is away from the vehicle, even if the spring / brake is released due to the driver forgetting to operate it or some other unexpected reason, it is arranged outside the vehicle. By operating the open / close switch, the braking state of the spring / brake can be prevented from being released, and the safety can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a layout position of a second opening / closing switch in the first embodiment of the present invention.

FIG. 3 is a diagram showing the configuration of a second embodiment of the present invention.

[Explanation of symbols]

 1, 21 Spring brake chamber 1a, 21a Air chamber 1b, 21b Spring 1c Chamber side push rod 2 Brake shoe 3, 31 Mechanical means 3a Idler lever 3b Cylinder side push rod 3c Wedge 3d Wheel cylinder 3e Piston 3f ball 3g inlet 4 solenoid valve 5 driver's seat switch 6 vehicle exterior switch 7 bumper 8 lid 9 door for getting on / off 10 camshaft 11 battery 12 spring brake tank 21c first push rod 21d second push rod 22 relay valve 23 Control valve

Claims (4)

[Claims] 1. A spring brake chamber that holds a spring in a pressed state when air pressure is present in the air chamber, and a brake shoe that is brought into a braking state by a force released by the spring when the air pressure disappears. In a spring-brake device comprising a mechanical means for setting and a control valve that applies air pressure to the air chamber when the vehicle is traveling to release the air pressure by an operation, the control valve is a solenoid valve, and the solenoid valve is an excitation valve. A spring / brake device comprising an opening / closing switch which is connected to release the air pressure when the electric current is cut off, and which is provided in the passage of the exciting current so as to be operated outside the vehicle. 2. The two opening / closing switches provided in series in the passage of the exciting current, the first of which is arranged in a driver's seat,
The spring / brake device according to claim 1, wherein the second one is arranged at a position where it can be operated outside the vehicle. 3. The spring / brake device according to claim 2, wherein the second of the opening / closing switches is configured to interlock with an outside operation switch of an entry / exit door of the vehicle. 4. An opening / closing switch arranged at a position where it can be operated outside the vehicle is interlocked with an automatic door opening / closing switch, and a relay valve is provided on a pneumatic pressure supply side of the solenoid valve, and the relay valve is controlled. The spring / brake device according to claim 1, wherein a control valve is provided in the pneumatic passage, and an operating end of the control valve is disposed in a driver's seat.