JPS63530Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve for a brake device, and more particularly to a spring brake control valve used in a spring brake device.

As is well known, a spring brake device is installed on large vehicles using air brakes, and its schematic piping system is shown in FIG. 1, for example. In Fig. 1, 1 is an air compressor, 2 is an air tank, 3 is an air supply pipe, 4 is a spring brake control valve installed near the instrument panel of the driver's cab, and 5 is attached to spring brake piping 6 near the wheels. 7 is a quick release valve,
8 is a spring brake cylinder, 9 is a brake rod, 10 is a swing lever, 11 is a camshaft for brake operation, 12 is a service brake air supply pipe, and 13 is a brake valve. Since the structure of each of these components is well known per se, a detailed explanation thereof will be omitted, and the prior art of a spring brake control valve related to the present invention will be explained with reference to FIG. 2.

In FIG. 2, the spring brake control valve 4 has three ports 4b, 4c, and 4d on a valve body 4a. and port 4
b is connected to the air supply pipe 3, port 4c is connected to spring brake pipe 6, and port 4d is open to the atmosphere. Valve body 4e
The spool 4f and knob 4g fixed thereto are always given an upward force in FIG. 2 by a spring 4h, but the air supply pipe 3
If the air pressure inside is higher than a predetermined value, the valve body 4e
is held at the position indicated by the two-dot chain line in FIG. 2, and the air supply pipe 3 and the spring brake pipe 6 are kept in communication via the spring brake control valve 4.

In the known spring brake device shown in FIGS. 1 and 2, when the pressure inside the air tank 2 is higher than a predetermined value, the spring 4h of the spring brake control valve 4 is in a compressed state, and the air supply pipe 3 is connected to a spring brake piping 6 via a spring brake control valve 4. Therefore, since the compressed air in the air tank 2 is introduced into the emergency braking chamber of the spring brake cylinder 8, no braking force is exerted through the brake rod 9. Now, step on the brake pedal and connect the service brake air supply pipe 12 to the spring brake cylinder 8.
When compressed air is fed into the service brake chamber, the brake rod 9 and the swing lever 10 are driven in the direction of the arrow in FIG. 1, and the brake actuating camshaft 11 is rotated.

On the other hand, when the pressure in the air tank 2 drops below a predetermined value, the spring 4h in the spring brake control valve 4 automatically pushes up the valve body 4e, cutting off communication between the ports 4b and 4c. At the same time, port 4c and port 4d communicate with each other, so spring brake cylinder 8
The emergency braking chamber is opened to the atmosphere via a quick release valve 7 and a spring brake control valve 4. Therefore, the brake rod 9 and the swing lever 10 are operated in the direction of the arrow in FIG. 1 to apply emergency braking.

On the other hand, when the spring brake is activated due to a drop in the pressure of the air source as described above, the pressure-responsive switch 5 provided in the spring brake piping 6 is activated.
Detects the pressure drop in the piping 6 and uses the opening and closing of the pressure responsive switch 5 as a spring brake activation signal, which lights up an indicator light on the instrument panel. When a vehicle that has been subjected to emergency braking in this manner is to be moved again and sent to a vehicle factory or the like for vehicle inspection, the knob 4g of the spring brake control valve 4 is manually pushed in to forcibly connect the ports 4b and 4b. 4c to release the spring brake.

The known spring brake device having the structure and function described above has the following problems.

(i) Since the pressure-responsive switch 5 is installed in an environment exposed to the outside air, such as under the floor of a vehicle, there are many opportunities for it to be exposed to water or vibration.
In order to prevent this, it is necessary to make the pressure-responsive switch waterproof and earthquake-resistant, which makes not only the pressure-responsive switch itself but also the entire device expensive.

(ii) The pressure-responsive switch was located far away from the driver's cab, resulting in long electrical lines and a complicated piping system.

(iii) Since the pressure-responsive switch is located outside the vehicle body, maintenance and inspection cannot be performed from the driver's cab, which is time-consuming.

On the other hand, Japanese Utility Model Application Publication No. 55-147956 discloses a technique related to an emergency brake system for a vehicle. However, in this technology, pressurized air is supplied to the parking brake device based on a detection signal from a pressure detection device that generates an electric signal when a pressure difference occurs between the supply of working fluid to the service brake device. A solenoid valve integrated with an emergency valve device installed in the pressurized air line is operated, and the parking brake device side of the pressurized air line is opened to the atmosphere to operate the parking brake device. There is. Therefore, it does not solve the above-mentioned problems, and the structure is complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a spring brake control valve for a spring brake device with a simple structure that is easy to maintain and inspect and has little risk of failure.

According to the present invention, in a pressure-responsive and manually operable spring brake control valve installed in an air circuit extending from an air pressure supply source to a spring brake cylinder, an outlet port connected to a spring brake piping of the valve is provided. communicates with a chamber provided at the bottom of the control valve through a pressure introduction port, the chamber is defined by a diaphragm, and is turned on and off by being pressed against the side of the diaphragm opposite to the outlet port by the operation of the diaphragm. A switch is provided, and the chamber in which the switch is provided is open to the atmosphere via a relief port.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4, but a description of parts designated by the same reference numerals as in FIGS. 1 and 2 in these figures will be omitted.

In the spring brake device according to the embodiment of the present invention, as shown in FIG. 4, the spring brake piping 6 is not provided with a pressure responsive switch, and as shown in FIG. A switch 13 is integrated. That is, the spring brake control valve 4A of the present invention shown in FIG. 3 is provided with a pressure introduction port 4i at its port 4c, and a diaphragm 13a and a switch 13b are incorporated in a chamber provided in communication with the port 4i. . Further, atmospheric pressure is introduced into the space on the switch side of the diaphragm 13a through a narrow relief port 4j. Therefore, the valve body 4e
When is in the solid line position in Fig. 3, the emergency braking chamber of the spring brake cylinder 8 is connected to the port 4 of the spring brake control valve 4A.
Since it is released to the atmosphere via d, switch 13
b is not activated, and an indicator light (not shown) connected to switch 13b lights up to notify that the spring brake is activated. On the other hand, the valve body 4e is connected to the spring 4
When h is compressed and pressed against the lower valve seat, ports 4b and 4c communicate with each other and high pressure air is introduced into the emergency braking chamber of the spring brake cylinder 8, so the spring brake is released. At this time, the switch 13b is actuated by the pressure acting on the diaphragm 13a through the pressure introduction port 4i. The indicator light (not shown) is then disconnected from its power source to notify the driver of the spring brake release.

As described above, the pressure-responsive switch, which was conventionally attached to the spring brake piping 6 at a location away from the spring brake control valve, is integrated with the spring brake control valve in the present invention, so the pressure-responsive switch is not exposed outside the vehicle. Therefore, there is no need to make the pressure-responsive switch waterproof and earthquake-proof, which simplifies the structure, and also eliminates the need for long electrical wiring, thereby reducing device costs. Furthermore, since the pressure-responsive switch is located near the instrument in the driver's cab, maintenance and inspection are easy, and the above-mentioned problems can be solved.
Furthermore, according to the present invention, a switch is provided that is turned on and off by a diaphragm in a chamber provided at the bottom of the control valve, so the wiring for the switch can be properly stored in the cab so that it does not get in the way.
Moreover, the switch can be integrally provided without interfering with the operation of the cab control valve.

In the above-mentioned embodiments, the present invention was explained on the assumption that it was applied to a brake system for emergency braking, but it should be noted that the present invention can also be applied to a gradual operation type control valve.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a piping system of a known spring brake device, FIG. 2 is a schematic vertical sectional view of a known spring brake control valve,
Fig. 3 is a longitudinal cross-sectional view of the main parts of the spring brake control valve improved by the present invention, and Fig. 4 shows an example of the piping system of the spring brake device realized using the spring brake control valve shown in Fig. 3. FIG. 4, 4A... Spring brake control valve, 5, 13... Pressure responsive switch, 8...
Spring brake cylinder.

Claims (1)

[Scope of utility model registration request] In a spring brake control valve that is pressure-responsive and manually operable and is installed in an air circuit from an air pressure supply source to a spring brake cylinder, the outlet port connected to the spring brake piping of the valve is connected via the pressure introduction port. The chamber is defined by a diaphragm, and a switch is provided on the side of the diaphragm opposite to the outlet port to be turned on and off by being pressed by the operation of the diaphragm. A spring brake control valve for a spring brake device, characterized in that a chamber in which the switch is provided is opened to the atmosphere through a relief port.