JP3138131B2 - Spring brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a vehicle. The present invention is particularly suitable for mounting on a bus. The present invention
In addition to service brakes operated by a brake pedal, the present invention relates to an improvement of a spring brake device provided for parking or the like.

[0002]

2. Description of the Related Art A spring brake device is a brake device which is used in an emergency when a pneumatic pressure (or hydraulic pressure) of a service brake is reduced or as a parking brake device, particularly mounted on a large vehicle. Conventional spring brake devices often use the brake shoes in common with service brakes.

[0003] A conventional spring brake device has a spring brake chamber in which a strong spring is incorporated. When there is air pressure in an air chamber of the spring brake chamber, 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 rod is activated regardless of the service pressure of the service brake. The shoe is configured to be driven to be in a braking state.

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

[0005]

In the spring brake device having such a structure, for example, when the driver has to temporarily go out of the vehicle, the spring brake device is put in a braking state, so that the vehicle is braked. Can be prevented from inadvertently starting, but the braking state can be easily released by the passenger mischieving the manually operated valve. Since this operation requires less power than the operation of releasing the parking brake, it is easy to operate.

An object of the present invention is to provide a device which improves safety by preventing a driver from releasing a braking state of a 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 the electromagnetic valve is connected so as to be in a non-braking state when the exciting current is flowing and to be in a braking state when the exciting current is cut off. Two or more open / close switches are provided in series in the path of the exciting current, and one of the switches is arranged at a position that can be operated outside the vehicle.

That is, the present invention provides a spring brake chamber for holding a spring pressed when there is air pressure in an air chamber, and a brake shoe by a force released by the spring when the air pressure disappears. A mechanical means for setting a braking state, and a control valve for applying air pressure to the air chamber during operation of the vehicle and releasing the air pressure by an operation, wherein the control valve is an electromagnetic valve, The solenoid valve is connected so as to release the air pressure when the exciting current is cut off, and is provided with an on / off switch disposed at a position operable outside the vehicle in a path of the exciting current.

[0009] The two coils provided in series in the path of the exciting current.
One of the on / off switches is disposed in a driver's seat, the second is disposed in a position that can be operated outside the vehicle, and the second of the on / off switches is a vehicle exterior operation switch of a door for getting on and off the vehicle. It is desirable to be linked.

An open / close switch arranged at a position operable outside the vehicle is interlocked with an automatic door open / close switch, and has 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 arranged in the driver's seat.

[0011]

When the driver leaves the driver's seat, he can operate the open / close switch outside the vehicle to bring the spring brake device into the braking state. Since the on / off switches are connected in series, if one of them is in the cutoff state, the exciting current of the solenoid valve is in the cutoff state. Even if you operate the open / close switch of the spring / brake device in the driver's seat or forget to operate the open / close switch of the spring / brake device when you leave the driver's seat, you can operate the open / close switch outside the vehicle to operate the spring. -The brake device can be maintained in a braking state.

The open / close switch on the outside of the vehicle is interlocked with a conventionally provided switch for opening and closing the door for getting on and off from the outside of the vehicle, so that the spring / brake is automatically opened when the door for getting on and off is closed from outside the vehicle. The device is in the braking state.

An open / close switch located at a position operable outside the vehicle is interlocked with the automatic door open / close switch, and a relay valve is provided on the pneumatic side of the solenoid valve. -Even if a valve is provided, the exciting current to the solenoid valve is in a cutoff state if the open / close switch outside the vehicle is operated. Therefore, even if the control valve is deliberately operated in the driver's seat, no air pressure is supplied to the air chamber of the spring brake chamber, and the braking state by the spring can be maintained.

[0014]

Next, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a view showing a configuration of a first embodiment of the present invention, and FIG. 2 is a view showing an arrangement position of a vehicle exterior open / close switch in the first embodiment of the present invention.

The first embodiment of the present invention comprises a spring brake chamber 1 for holding the spring 1b pressed when air pressure is present in the air chamber 1a, and a force for releasing the spring 1b when the air pressure disappears. A mechanical means 3 for setting the brake shoe 2 to a braking state by means of a solenoid valve 4 used as a control valve for applying air pressure to the air chamber 1a during operation of the vehicle and releasing the air pressure by 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 open / close switches are provided in a passage of the exciting current, one of which is provided. The driver's seat switch 5 is disposed in the driver's seat, and the other switch is disposed outside the vehicle as a switch 6 outside the vehicle. The external switch 6 is configured in conjunction with an external device switch of a door for getting on and off the vehicle, is disposed inside the bumper 7 as shown in FIG. 2, and is concealed by the lid 8 so as not to be operated unintentionally.

The mechanical means 3 is provided with a spring
Push rod 1 on the chamber side of brake chamber 1
c, a cylinder-side push rod 3b that moves in accordance with the rotation of the idler lever 3a, and a tip portion formed on a cone fixed to the cylinder-side push rod 3b. Through a wedge 3c, a wheel cylinder 3d slidably disposed inside the wedge 3c, and a ball 3f slidably disposed inside the wheel cylinder 3d and disposed on the conical surface of the wedge 3c. And two pistons 3e for receiving the opening / closing operation and transmitting the operation to the brake shoe 2.

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

Normally, when the vehicle is running or temporarily stopped, the driver's seat switch 5 and the vehicle exterior switch 6 are in the closed state, 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 power supply. In the example shown in FIG. 1, the chamber-side push rod 1c that has received the air pressure is pushed downward and stops while compressing the spring 1b.

The movement of the chamber-side push rod 1c causes the idler lever 3a to rotate about the fulcrum P, and pulls out the wedge 3c connected to the cylinder-side push rod 3b. 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 that are in contact with the ball 3f move inside. With this movement, each of the brake shoes 2 receiving the urging force of the return spring (not shown) moves 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 presses a 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 cut off, and the solenoid valve 4 discharges the air in the air chamber 1a to the outside. I do. With the release of the air pressure, the spring 1b expands and pushes back the chamber side push rod 1c to 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.
The wedge 3c with which the ball 3f contacts by this movement
The outer diameter of the conical surface becomes larger, the pistons 3e are respectively pushed outward, and the brake shoes 2 are opened to be in a braking state.

When the vehicle stops and the driver goes out of the vehicle, the driver's seat switch 5 is opened. This places the spring brake in a braking state. However, this operation may be forgotten, or may be closed for other unexpected reasons despite having been in the open state. If there is such a concern, even if the driver leaves the driver's seat, the driver opens the cover 8 shown in FIG. Are connected in series, so that battery 1
The supply of power from the power supply 1 to the solenoid valve 4 is stopped, and as described above, the supply of air pressure to the air chamber 1a of the spring brake chamber 1 is not performed, and the braking state can be maintained.

The outside switch 6 is provided with a door 9 for getting on and off the vehicle.
When the door for getting on and off 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 a second embodiment of the present invention. In the second embodiment of the present invention, the air chamber 21
a spring brake chamber 21 that keeps spring 21b pressed when air pressure is present
Mechanical means 31 for setting the brake shoe 2 to a braking state by the force released by the spring 21b when the air pressure disappears, and a solenoid valve for applying air pressure to the air chamber 21a during operation of the vehicle to release the air pressure by 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 control air pressure passage of the relay valve 22 and having an operation end disposed in a driver's seat. An external switch 6 is provided at a position operable outside the vehicle and is interlocked with an external operation switch of a door for getting on and off the vehicle.

The mechanical means 31 includes a first push rod 21 c 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 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 so that the solenoid valve 4 is opened and the relay valve 2 is opened.
Air pressure from 2 is applied to the spring brake chamber 21
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 is lowered, and the tip of the brake shoe 2 is camshafted by the urging force given by a spring (not shown). It moves to the recess of No. 10 and the braking is released.

[0029] When the control valve 23 in which the vehicle is stopped and the driver is provided in the driver's seat to the closed state, relay
The supply of air pressure to the valve 22 is stopped, and the relay valve 22 closes the air pressure supply path to the solenoid valve 4, opens the exhaust port, and discharges air in the air chamber 21 a of the spring brake chamber 21. Discharge via valve 4. With the release of the air pressure, the spring 21b expands and pushes up the first push rod 21c and the second push rod 21d. This push-up causes the camshaft 10 to rotate and push the tip of the brake shoe 2 open to bring it into a braking state.

As described above, when the driver operates the control valve 23 to close the valve, the driver enters the braking state by the spring 21b. Therefore, in order to prevent such a situation, the exterior switch 6 is operated to be opened. When the exterior switch 6 is opened, the voltage of the battery 11 is not applied to the solenoid valve 4, and the solenoid valve 4
The supply of air pressure from the valve 22 is stopped, and the spring
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 into the braking state as described above. Thereby, the control valve 2
Even if the operation of 3 is forgotten or the passenger performs an operation of opening the air chamber 21a, the air pressure is not supplied from the solenoid valve 4 to the air chamber 21a, and the braking state is maintained. Outside switch 6
When the exterior switch 6 is opened and the spring brake device is put into the braking state, the entrance / exit door closes automatically and the passengers You can avoid getting off.

[0032] When the driver to ride by the outside switch 6 closed, the battery 1 to the electromagnetic valve 4
1, 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, which closes the discharge port and supplies the air pressure to the solenoid valve 4. Open.
As a result, air pressure is supplied to the air chamber 21a of the spring brake chamber 21, and the spring 21b is depressed to release the braking state.

In the conventional apparatus, a relay valve is provided as a control valve for controlling the air pressure of the spring brake chamber, and the control valve is provided to the relay valve via a manually operated valve provided in a driver's seat. Therefore, the second embodiment of the present invention can be realized by changing only the provision of the solenoid valve among the main components indicated by the two-dot chain line in FIG.

[0034]

As described above, according to the present invention, even if the spring brake is released due to forgetting operation or other unexpected reasons when the driver is away from the seat, the driver is disposed 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 the drawings]

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

FIG. 2 is a diagram showing an arrangement position of a second open / close switch according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a 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 Outside switch 7 Bumper 8 Lid 9 Door for getting on and off 10 Camshaft 11 Battery 12 Spring brake tank 21c First push rod 21d Second push rod 22 Relay valve 23 Control Valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60T 7/02 B60T 13/38

Claims (2)

(57) [Claims] 1. A spring when air pressure is present in an air chamber.
Spring and brake
The chamber and the spring when the air pressure is extinguished.
Sets the brake shoe in the braking state by the force released by
Mechanical means for applying air pressure to the air chamber when the vehicle is running.
And a control valve for releasing the air pressure by giving operation.
In the spring brake device, the control valve is a solenoid valve, and the solenoid valve interrupts the exciting current.
Connected to release said air pressure when disconnected
In the path of the exciting current so that it can be operated outside the vehicle.
Open / close switch arrangedIs provided, Two open / close switches are provided on both sides of the exciting current path.
Also shuts off the exciting current unless operated to the closed state.
The first is placed in the driver's seat,
Is located in a position where it can be operated outside the vehicle, The second of the open / close switches is outside the door of the vehicle.
When the door is closed in conjunction with the operation switch,
Dynamically opened A spring bus
Rake device. (2)Spring when air pressure is in the air chamber
Spring and brake
The chamber and the spring when the air pressure is extinguished.
Sets the brake shoe in the braking state by the force released by
Mechanical means for applying air pressure to the air chamber when the vehicle is running.
And a control valve for releasing the air pressure by giving operation.
Spring and brake equipment, The control valve is a solenoid valve, and the solenoid valve blocks an exciting current.
Connected to release said air pressure when disconnected
In the path of the exciting current so that it can be operated outside the vehicle.
A placed on-off switch is provided, A relay valve provided on the air pressure supply side of the solenoid valve
Installed in the control air pressure passage of this relay valve
Control valve
The operating end of the lube is located in the driver's seat, An open / close switch located at a position that can be operated outside the vehicle.
Switch on and off the door of the vehicle
The door is automatically opened when the door is closed Specially
Spring brake device.