JPS628214Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a brake locking device for a motor vehicle such as a mixer truck or a crane truck, which operates when the vehicle is stopped.

In this type of vehicle, it is desirable to use a brake lock device in combination with the parking brake in order to improve safety when stopping the vehicle. To explain with reference to FIG. 1, the air flows from the air tank 1 through the brake valve 2,
A service brake system connected to the brake booster 4 via the double check valve 3 by piping 5, 6, 7, respectively, and piping 8, 9 separately from the system connecting the double check valve 3 from the air tank 1. , 10, and a brake lock system in which a pressure reducing valve 11 and a brake locking solenoid valve 12 are arranged. It is connected to a control circuit consisting of a parking brake switch 17 operated by a lever.

As a result, when the parking brake lever is operated when the brake is locked, by keeping the manual switch 14 closed, the parking brake is applied and the parking brake switch 17 is closed.
Current flows through the coil 16a of the relay 16 and the parking brake switch 17, and the contacts 16c and 16d are connected by the contact piece 16b energized by the coil 16a of the relay 16.
9, the brake lock solenoid valve 12 is energized through the relay 16 and the conductor 20.

The electromagnetic valve 12 opens due to the energization, and the compressed air in the air tank 1 passes through the piping 8, the pressure reducing valve 11, the piping 9, the electromagnetic valve 12, the piping 10, the double check valve 3, and the piping 7 to the booster 4. Because of the inflow, the booster 4 operates and generates hydraulic pressure,
The hydraulic pressure acts on the brake wheel cylinder 22 through the hydraulic pipe 21, thereby locking the brake.

However, in the conventional parking brake switch 17, when the parking brake lever is operated, the circuit is closed regardless of the operating force of the lever, so the parking brake lever is not operated sufficiently, and therefore the parking brake cannot be operated reliably. Even when you are not
A problem arises in that only the brake lock device operates, and there is a risk that the safety of the dual brake system in which both brakes are used together may be impaired. In addition, the brake valve 2
The drawback is that the much-needed ease of operation, which can be operated independently of the service brake system, cannot be taken advantage of. Furthermore, as mentioned above, the parking brake switch 17 closes regardless of the operating force of the parking brake lever, so there is a possibility that the circuit may close due to vibration etc. while driving, and if you forget to open the manual switch 14. There is also a risk that the brakes will be applied suddenly if the vehicle is turned on.

In order to solve this problem, it is possible to close the parking brake switch when the operation of the parking brake lever exceeds a predetermined stroke. Since the stroke changes due to wear, a satisfactory result has not been obtained.

However, Utility Application No. 51-82039 (Utility Application No. 53-427)
No.) As per the publication, the operating load detection element of the parking brake, the electromagnetic cutoff valve installed immediately after the brake operating device of the fluid system of the liquid-operated service brake, and the electromagnetic cutoff valve inserted into the electrical system of the electromagnetic cutoff valve to prevent parking. The system includes a control element that responds to a brake operation load detection element and controls the current to the electromagnetic cutoff valve when the parking brake load exceeds a predetermined parking brake load. activates the fluid-operated service brake, then activates the parking brake, responds the control element to the parking brake operation load detection element to close the electromagnetic cutoff valve, and then releases the pedal and activates the parking brake. There is a parking brake that is attached to a fluid-operated service brake that can be operated in conjunction with a fluid-operated service brake.
This method uses an electromagnetic cutoff valve to confine the brake pressure inside the service brake after the service brake is activated. If the brake pressure is applied for a long time, brake fluid, compressed air, etc. will leak from the brake system, and the brakes will not work properly. There is a danger that it will disappear. Further, since the electromagnetic cutoff valve is inserted after the brake operating device of the service brake system, if the electromagnetic cutoff valve malfunctions and leaks, there is a risk that the service brake will not work. Furthermore, in the above-mentioned application, the micro switch that activates the electromagnetic cutoff valve is turned on while the parking brake is applied, so there is a risk that the electromagnetic cutoff valve may be activated before the parking brake is properly applied (page 9, line 19 of the above specification of application). As a result, the safety of double braking cannot be ensured as described above.

Furthermore, Japanese Utility Model Application Publication No. 51-34129 describes a device that electrically detects and displays whether the parking brake is activated or inactivated, in order to confirm that the parking brake is working effectively. In order to easily detect cable tension on a daily basis, a tension detection device is interposed in the middle of the tension cable, and this tension detection device is connected to a cylinder and a piston slidably disposed within the cylinder. and a rod, which is disposed in the cylinder and always urges the piston inward, and is compressed when the brake operating force (specifically, the tension of the tension cable) reaches a predetermined value or more. A device is disclosed in which the tension detecting device is constructed of a spring and a brake switch that is provided in the cylinder and opens and closes by the movement of the piston relative to the cylinder. Therefore, the spring must be compressed so that the brake switch closes when the brake operating force reaches a predetermined value or more.
When the brake operating force reaches a predetermined value or more, the conductive piece comes into contact with the conductive washer constituting the brake switch, so the stroke is small and the contact may be incomplete.

In view of the above, the present invention was devised to provide a brake lock device with a simple structure and reliable operation.
The gist of the system is to connect two air passages from the air tank through the brake valve and the parking brake solenoid valve to the brake booster via a double check valve, and to connect the two air passages from the air tank through the brake valve and parking brake solenoid valve to the brake booster through a double check valve. A parking brake lever and a parking brake activation wire are attached to one side of the operating lever, and a parking brake switch that is turned on when the distance between the operating levers is opened is attached to one or the other of the operating levers. The present invention is configured to operate the booster.

Hereinafter, the present invention will be explained in detail based on the illustrated embodiment.The brake systems of the service brake system and brake lock system and their control circuits in the present invention are the same as those shown in FIG.

FIG. 2 shows a parking brake lever device according to the present invention, where 40 is a parking brake lever, 41
is an operating lever formed of spring steel into a bifurcated shape with one piece 41a and the other piece 41b, one end of which is connected to the shaft 4.
2, one piece 41a is connected to the parking brake lever 40, and the other piece 41b is attached to a micro switch 43 constituting a parking brake switch.

When the micro switch 43 is not operating the parking brake shown in FIG.
1a and is open, and the parking brake lever 40 is operated by a predetermined value or more, and the operating lever 4
When one piece 41a and the other piece 41b of No. 1 expand and the distance between them changes, a circuit is closed.

Note that the predetermined value refers to the parking brake lever 40.
This refers to the operating force applied to the lever when the parking brake force is generated in the vehicle when the parking brake is pulled by the set stroke.

Note that 44 in the figure is a piece 4 of the operating lever 41.
This is a parking brake actuation wire with one end connected to 1a.

This embodiment is configured as described above.
When the parking brake lever 40 is pulled upward in the figure from the non-operated state of FIG. 2a, in the initial stage of operation, the operating lever 41 is pulled toward the shaft 4 while maintaining the state of FIG. 2a.
The parking brake is actuated by rotating the parking brake actuating lever 40 clockwise around the center 2 in the drawing and pulling up the wire 44. When the parking brake actuating lever 40 is further pulled upward and the operating force reaches or exceeds a predetermined value, the upper piece 41a of the actuating lever 41 is bent as shown in FIG. 2b, and the one piece 41a and the other piece 41b are spread apart, and the actuator 43a of the microswitch 43 separates from the one piece 41a, and the switch 43 opens.

Therefore, by changing the spring force of the piece 41a of the operating lever 41 made of spring steel, it is possible to freely select the operating force of the parking brake lever 30 that operates the micro switch 43, that is, the parking brake force. can.

As described above, the present invention connects the two air passages from the air tank through the brake valve and the parking brake solenoid valve to the brake booster via the double check valve, and supports the base end rotatably. A parking brake lever and a parking brake activation wire are attached to one side of the bifurcated actuation lever, and a parking brake switch that is turned on when the distance between the actuation levers opens is attached to one or the other side, and the switch operates the solenoid valve. Since the brake lock system is configured to operate the booster through the brake system, the brake lock system can be operated independently of the service brake system, and in this case, the solenoid valve is opened only when the device of the present invention is operated, and the brake lock system is operated independently of the service brake system. Compressed air is continuously sent to the service booster, so even if there is a slight air leak in the brake system, the brakes will not loosen and are safe. It will be equipped with a three-brake system,
Not only is it safer, but even if one of the brake systems breaks down, the remaining system can be activated to ensure immediate safety.

Further, according to the present invention, a parking brake lever and a parking brake activation wire are attached to one side of the bifurcated operating lever, and a parking brake switch that is turned on when the distance between the operating levers is widened is attached to one or the other side thereof. This not only simplifies the structure, but also allows one piece of the operating lever to be bent when an operating force of a predetermined value or more is applied to the parking brake lever.
Eliminates the need for springs in tension detection devices,
In addition, in the parking brake switch, when the distance between the one piece and the other piece widens due to the deflection, the actuator protrudes and turns on, so the contact is complete and operation is ensured, and the parking brake switch closes and the brake lock system is activated. When this happens, the parking brake is definitely working.

Therefore, the safety of the double brake, which uses both the parking brake and the brake lock system when stopping the vehicle, can be reliably maintained. In addition, even if the driver forgets to open the manual switch while driving, the parking brake switch will not close due to a slight stroke caused by vibration, etc.
This can prevent problems such as sudden braking while driving.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the brake lock device of the present invention.
FIGS. 2a and 2b show a parking brake lever device according to the present invention, and are partially cutaway front views. 1: Air tank, 2: Brake valve, 4: Booster, 12: Brake lock solenoid valve, 14:
Manual switch, 16: Relay, 17: Parking brake switch, 40: Parking brake lever, 41:
Forked actuation lever, 41a: one piece of forked actuation lever, 41b: other piece, 43: parking brake switch.

Claims (1)

[Scope of utility model registration request] Two air passages from the air tank, passing through the brake valve and the parking brake solenoid valve, respectively, are connected to the brake booster via a double check valve, and the base end is connected to one piece of a fork-shaped operating lever that is rotatably supported. A parking brake switch that is turned on when the distance between the operating levers opens is attached to one or the other of the parking brake levers and the parking brake operating wire, and the switch operates the booster via the solenoid valve. An automobile brake locking device configured to