JPS5854289Y2 - discharge valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge valve used in a vehicle air brake system.

This discharge valve is similar to the brake valve, brake pipe, and button.
Connected to the J-fit valve, it forms a passage for supplying and discharging pressurized air from the brake pipe when the driver operates the brake valve or handle, and also when an emergency brake command is issued to activate an emergency brake device such as a detsutman or ATS. The brake pipe pressure is reduced by operating a pilot valve.

A conventional discharge valve is shown in FIG. 1 and described below.

1 is a base body provided with a discharge port 2, a valve chamber 3, and a pressure chamber 4; a bushing 5 and a bushing 6 are mounted inside the base body 1; the bushing 6 has a hole 6a communicating with the pressure chamber 4; It is perforated.

A lid 8 is attached to this base 1 via a gasket 7,
Thus, the valve body 9 is constructed.

A piston 10 is slidably fitted into the valve body 9.

The piston 10 includes a large diameter sliding portion 11 that slides on the inner surface of the bush 5, a small diameter sliding portion 12 that slides on the inner surface of the bush 6,
A passage 13 communicating with the valve chamber 3 is connected to a small central diameter portion 14 formed between the bushing 6, and a valve 16 is attached to the lower part of the piston 10 via a spring 15, and the valve 16 is attached to the base body. 1 to close the discharge port 2.

A spring 18 is interposed between the piston 10 and the lid 80, and the spring 18 always presses the piston 10 downward.

From the bushing 5, the lid 8 and the piston 10, that is, the valve body 9
A pilot chamber 20 is formed by the piston 10 and the piston 10 .

A pilot valve 23 is connected to a pilot passage hole 2.1 communicating with the pilot chamber 20 via a shutoff cock 22, and a supply hole 25 having a throttle 24 and communicating with the pilot chamber 20 communicates with the valve chamber 3. 3 is the supply/discharge port 26 of the brake valve 26
It is continuous with a.

The pressure chamber 4 is connected to the brake pipe 27, and the supply port 26b of the brake valve 26 is connected to a pressure air source (not shown).

Next, the operation of the above-mentioned conventional discharge valve will be explained.

In the state shown in FIG. 1 in which the pilot valve 23 is in the closed position (exhaust port 23a closed) and the brake valve 26 is in the relaxed position (exhaust port 26c closed) and pressurized air is filled in the brake pipe 27 and the pilot chamber 20, the ATS When an emergency brake command is transmitted to the pilot valve 23, the pilot valve 23 switches to the open position (the exhaust port 23a opens), and the pressurized air in the pilot chamber 20 passes through the pilot hole 21 to the pilot valve 23. is rapidly discharged into the atmosphere from the exhaust port 23a.

At this time, the pressurized air in the passage 13 flows into the pilot chamber 20 through the restriction 24, and a large pressure difference is generated between the pilot chamber 20 and the passage 13 due to the restriction 24.

Because of this pressure difference, the force with which the spring 18 and the air in the pilot chamber 20 press the piston 10 downward (hereinafter referred to as downward pressing force) is equal to the force with which the air in the passage 13 presses the piston 10 upward (hereinafter referred to as downward pressing force). (referred to as an upward pressing force), the piston 10 rises all at once, and the retaining ring 30 closes the valve 1.
6 is lifted to communicate the pressure chamber 4 with the discharge port 2.

Therefore, the pressurized air in the brake pipe 27 is discharged to the atmosphere, and the brake pipe 27 is extremely depressurized.

Further, in the state shown in FIG. 1, when a normal brake is commanded, that is, when the brake valve handle 26e is operated to the brake position, the supply port 26b of the brake valve 26 is closed.
The exhaust port 26c is opened, and the pressurized air in the brake pipe 27 passes through the pressure chamber 4, the hole 6a, the passage 13, the valve chamber 3, and the supply/discharge port 26a, and is discharged from the exhaust port 26c into the atmosphere. is depressurized.

At this time, the pressure air in the pilot chamber 20 flows out through the supply hole 25 at a level where the pressure in the pilot chamber 20 becomes the same as the pressure in the brake pipe 27, but the downward pressing force acting on the piston 10 is always greater than the upward pushing force, so the piston 10 maintains its it position.

After normal braking by this bundle operation, when pressurized air is to be filled into the brake pipe 27 and pilot chamber 20, the brake valve handle 26e is returned to the relaxed position.

Pressure air from a pressure air source (not shown) is supplied to the brake valve 2.
6 and is supplied to the pilot chamber 20 and the brake pipe 27.

At this time, due to the restriction 24 of the supply hole 25, the pressure in the pilot chamber 20 increases more slowly than the pressure in the passage 13, creating a pressure difference between the pilot chamber 20 and the passage 13.

Due to this pressure difference, the upward pressing force acting on the piston 10 becomes larger than the downward pressing force, and the piston 10 rises.

As the piston 10 rises, the pressure in the pilot chamber 20 increases, and the downward pressing force becomes larger than the upward pressing force, causing the piston 10 to descend.

As the piston 10 descends, the pressure in the pilot chamber 20 decreases, and the upward pressing force becomes greater than the downward pressing force, causing the piston 10 to rise.

Therefore, the piston 10 repeats this vertical movement.

Furthermore, when pressurized air is suddenly supplied, the pressure difference between the pilot chamber 20 and the passage 13 increases sharply, causing the piston 10 to rise at once, closing the passage 13 and communicating the pressure chamber 4 and the discharge port 2. Sometimes.

In other words, with conventional discharge valves, when pressurized air is filled into the brake pipe after normal braking, the piston moves up and down, causing a squealing phenomenon, or in extreme cases, the same condition as when an emergency brake command is issued. There was a problem.

The present invention solves the above problem by providing the supply hole that supplies pressurized air to the pilot chamber with a check valve that prevents the pressure air from flowing back from the pilot chamber to the supply hole.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

FIG. 2 shows an embodiment of the discharge valve according to the present invention, and the same components as in the conventional one are denoted by the same reference numerals as in FIG. 1, and the explanation thereof will be omitted.

Reference numeral 50 denotes a check valve provided at a portion of the lid 8 where the supply hole 25 opens into the pilot chamber 20, and the check valve 50 is seated on and removed from a valve seat 51 formed on the lid 8. It consists of a valve 52, a spring 53 that presses the valve 52 against the valve seat 51, and a support portion 55 that supports the spring 53 and has a hole 54.

Next, the operation of this discharge valve will be explained.

The pilot valve 23 is in the closed position (exhaust port 23a closed) and the brake valve 26 is in the relaxed position (exhaust port 26c closed), and the brake pipe 27 and pilot chamber 20 are filled with pressurized air as shown in FIG. When the emergency brake command from the ATS or the like is transmitted to the pilot valve 23, the pilot valve 23 switches to the open position (the exhaust port 23a opens), and the pressurized air in the pilot chamber 20 flows through the pilot hole 21. Then, it is rapidly discharged into the atmosphere from the exhaust port 23a of the pilot valve 23.

At this time, the pressurized air in the passage 13 flows into the pilot chamber 20 through the restriction 24 and the check valve 50, and a large pressure difference is generated between the pilot chamber 20 and the passage 13 due to the restriction 24.

Due to this pressure difference, the downward pressing force acting on the piston 10 becomes smaller than the upward pressing force, causing the piston 10 to rise all at once, causing the retaining ring 30 to lift up the valve 16, closing the passage 13 and closing the pressure chamber 4. communicates with the discharge port 2.

Therefore, the pressurized air within the brake pipe 27 is discharged to the atmosphere, and the brake pipe 27 is extremely depressurized.

Further, when the normal brake is commanded in the state shown in FIG. 2, that is, when the brake valve handle 26c is operated to the brake position, the supply port 26b of the brake valve 26 is closed and the supply/discharge port 26a is closed. The pressurized air in the brake pipe 27 is discharged into the atmosphere from the exhaust port 26c through the pressure chamber 4, the hole 6a, the passage 13, the valve chamber 3, and the supply/discharge port 26a of the brake valve 26. The brake pipe 27 is depressurized.

At this time, the check valve 50 prevents the pressure air in the pilot chamber 20 from flowing out to the supply hole 25, and the pressure in the pilot chamber 20 is maintained at a constant pressure.

During brake release after this normal brake application, pressurized air from the pressure air source is supplied to the supply port 2 of the brake valve 26.
6b1 supply/discharge 26a1 valve chamber 3, passage 13, hole 6 a %
It is supplied to the brake pipe 27 via the pressure chamber 4.

At this time, the pressure in the pilot chamber 20 is maintained at the same pressure as before normal braking, as described above.
Even if the pressure air supply is suddenly carried out, the piston 10
The upward pressing force acting on the surface is never greater than the downward pressing force.

Therefore, when the brake is released, the piston 10 does not move up and down and makes a noise, and the pressure chamber 4 does not communicate with the discharge port 2 to become in an emergency flare production state.

FIG. 3 shows a configuration in which pressurized air can also be supplied from the pilot valve 23 to a pilot chamber (not shown) of the discharge valve 70.

That is, a three-way solenoid valve is used as the pilot valve 23, and pressurized air from a pressure air source (not shown) is supplied to the supply port 23.
It is poured into the pilot chamber via the c1 supply/discharge port 23b.

When the emergency brake command is transmitted to the pilot valve 23,
The solenoid 23e is energized and the spool valve 23d is switched to close the supply port 23c and communicate the supply/discharge port 23b with the exhaust port 23a.

The subsequent actions of the discharge valve 70 during emergency braking and during normal braking are the same as those shown in FIG. 2, and therefore their explanations will be omitted.

As is clear from the above explanation, the discharge valve of the present invention has a check valve in the supply hole that has a throttle and supplies pressurized air to the pilot chamber, and prevents the backflow of pressurized air from the pilot chamber to the supply hole. According to the present invention, when the brake is released after normal braking (when pressurized air is supplied)
The vertical movement of the piston (squealing phenomenon) and the accidental emergency braking action can be completely prevented, improving the reliability of the discharge valve.

In addition, as mentioned above, the present invention is extremely practical because it is possible to obtain the special effects as mentioned above by simply adding a check valve to the supply hole of the conventional discharge valve. It is something.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional discharge valve, FIG. 2 is an explanatory diagram of an embodiment of the devised discharge valve, and FIG. 3 is an explanatory diagram showing another usage state of the same discharge valve. 4...Pressure chamber, 9...Valve body, 10...
...Piston, 20...Pilot chamber, 2
1... Pilot A hole, 24... Throttle, 25... Supply hole, 50... Check valve.

Claims (1)

[Scope of utility model registration request] A piston that is slidably fitted into a valve body, a pilot chamber formed by the piston and the wall of the valve body, a pilot passage communicating with the pilot chamber and connected to the pilot valve, and a throttle, and the pilot a pressure chamber that communicates with the chamber and is connected to the brake valve; and a pressure chamber that is connected to the brake pipe and communicates with the atmosphere or with the supply hole when the piston slides, and the pressure chamber 1. A discharge valve in which the pressure in the pressure chamber is reduced by the above, characterized in that the supply hole is provided with a check valve that prevents the flow of pressurized air from the pilot chamber to the supply hole.