JPS5811981Y2 - benzouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a valve device used for automatic control of moving parts of a machine tool.

Conventionally, the air pressure on the primary side of the main flow path provided in the casing operates a pressure-sensitive member such as a diaphragm or a piston, which in turn drives a valve body that opens and closes the main flow path, thereby opening and closing the main flow path. A pilot type solenoid valve device is now provided.

(For example, November 1963, published by Nikkan Kogyo Shimbun, pneumatic equipment and application circuits) These solenoid valve devices, for example, as shown in FIG.
is held on the open/closed side of the flow path, and pressurized air in the main flow path 22 is applied to a pressure-sensitive operating member such as a piston 23 or a diaphragm to move the valve body 21 in the direction of opening the main flow path, or as shown in FIG. Piston 24 or diaphragm front face 24
Air of the same pressure is sent from the flow path to the front surface 24 a and the rear surface 24 b, and the difference in the area between the front surface 24 a and the rear surface 24 b causes a difference in the force applied to the pressure-sensitive operating member such as the piston 24 or the diaphragm. , this causes piston 2
4 or the diaphragm is operated, and the operation is transmitted to the valve body 25 to open the main flow path.Even in this case, in order to completely seal the main flow channel 22 when the valve device is closed, the valve body 25 is normally biased in the valve opening direction by the force of a spring 26.

The opening and closing operations of the valves are both performed by opening and closing the pressurized air supply path 28 using the electromagnetic valve 27 and operating the pressure-sensitive operating member.

Therefore, in order to hold these valve bodies 21 and 25 in a position where the main flow path is opened, it is necessary to supply a pilot pressure of a certain pressure or more to the pressure reducing member.

However, the main flow path 2 connected to such a valve device
If an accident occurs in a part of the air circuit (2) and pressurized air is suddenly released into the atmosphere, or if a large volume air control device is suddenly filled with pressurized air, the pressure in the air circuit may drop to the specified pressure. As the pressure decreases further, the force of the pilot pressure that operates the pressure-sensitive operating members such as the piston or diaphragm of the valve device described above weakens, and the valve may be moved in the opening/closing direction by the spring or unstable movement of the valve may occur. In turn, this caused malfunctions in automatically controlled machine tools and the like.

Therefore, the present invention aims to prevent the main flow path of the valve device from being closed or the valve body for opening and closing the main flow to become unstable even if the air pressure in the air control circuit suddenly drops below a predetermined pressure in this type of valve device. The purpose of this valve device is to provide a valve device that does not perform any erroneous operation, and the gist of the configuration for achieving this purpose is to include a main flow path and a valve body that opens and closes the main flow path in a valve casing. , a pressure-sensitive operating member such as a piston or a diaphragm that biases the valve body toward the main flow passage closing side with a spring, and operates the valve body in a direction in which the main flow passage is opened against the spring by introducing pilot pressure; A valve device comprising: a solenoid valve for opening and closing the pilot flow passage, the pilot flow passage for introducing pilot pressure into the pressure-sensitive operating member communicating with the primary side of the main flow passage;
The pilot flow path is equipped with a check valve that is opened by the pressure on the primary side of the main flow path, and if the pressure on the primary side of the main flow path suddenly decreases due to some unexpected cause, the check valve opens the pilot flow path. , prevents the pilot pressure introduced into the pressure reducing member from flowing back into the main flow path, and as long as the pilot solenoid valve opens the pilot flow path, the pilot pressure during normal operation is accumulated and the main flow path is opened. The idea was to maintain the open state and achieve the intended purpose.

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

In this embodiment, the front part of the piston, which is a pressure-sensitive operating member, communicates with the inside of the main flow path, and the back part of the piston communicates with the outside air and the main flow path in a switchable manner using a solenoid valve, in order to obtain the operating force of the main valve. Now, a valve device in which the area of the front surface of the piston is smaller than the area of the rear surface will be explained.

In the figure, 1 is the casing.

This casing 1 has a main flow path 2 that constitutes an air control circuit.
is formed, and a valve seat 3 is located approximately in the center of the main flow path 2.
A valve element 4 is disposed within this valve seat 3 so as to be freely fitted therein.

The valve body 4 has a piston whose front surface 5a is exposed in the main flow path 2 and is connected to a pressure-sensitive operating member by a shaft 6, and is opened and closed by the movement of the piston 5.

Further, even when the air pressure in the main flow path is low, the valve spring 17 biases the valve body 4 so that the valve body 4 is firmly seated on the valve seat 3 to obtain a complete seal.

The piston 5 is movably fitted into a cylinder 7 formed with one end open to the main flow path 2.

This cylinder 7 has a small diameter part 7a formed at its opening part, a large diameter part 7b formed at its back part, and a piston 5.
The front face 5a is fitted to the small diameter portion 7a of the cylinder 7, and the back face 5b is fitted to the large diameter portion 7b of the cylinder 7 in an airtight manner.

An air inlet/outlet 8 is formed on the surface of the cylinder 7 facing the back surface 5b of the piston 5, and the air inlet/outlet 8 is connected to a pilot flow path 9 communicating with the primary side of the main flow path 2. An exhaust hole 10 which can be opened to the outside air is communicated via a solenoid valve 11.

The valve body 12 of the solenoid valve 11 connects either the pilot flow path 9 or the exhaust hole 10 to the air inlet/outlet 8 of the cylinder 7.
The valve element 12 of the electromagnetic valve 11 is used to switch between the two.

A valve chamber 13 is formed in the pilot flow path 9, and a valve body 14 is inserted into the valve chamber 13 with a spring 15.
The check valve 16 is biased and accommodated on the main flow path 2 side of the valve 3.

This valve device is constructed as described above, and when air at a predetermined pressure is supplied to the primary side of the flow path 2, the solenoid valve 11 is operated to open the exhaust hole 10 and the air inlet/outlet 8 of the cylinder 7. When the front surface 5a of the piston 5 is brought into communication with the
By being greater than the atmospheric pressure on b, the piston 5
is pushed in, and together with this, the valve body 4 moves and fits into the valve seat 3, and the main flow path 2 is closed.

On the contrary, pressurized air passes through the pilot flow path 9 via the check valve 16 into the cylinder 7 that communicates the pilot flow path 9 with the air inlet/outlet 8 of the cylinder 7.
flow into the world.

At this time, since the area of the back surface 5b of the piston 5 is larger than that of the front surface 5a, when the force due to the area difference exceeds the valve spring force that biases the valve body 4, the piston 5 is pushed out and the valve body 4 is moved, and the main flow Path 2 becomes open.

Also, in this state, if the air pressure in the main flow path 2 suddenly decreases, the pilot flow path 9 is closed by the check valve 16, the air on the back surface of the piston 5 is sealed, and the piston 5 is pushed out at a predetermined pressure. This state is maintained, and the valve body 4 is maintained without closing the main flow path 2.

In this way, in the present invention, by providing the tunnel stop valve in the pilot flow path of the pilot-operated solenoid valve device, even if the air pressure in the main flow path decreases, the open state of the valve remains at the predetermined pressure. Even in the event of an accident in the air control circuit, the main flow path will remain open and the operation of the valve body will be stable, preventing malfunctions in the controlled equipment. There is nothing left to do.

[Brief Description of the Drawings] Fig. 1 is a schematic sectional view of an example of a conventional valve device, Fig. 2 is a schematic sectional view of another example, and Fig. 3 is a sectional view of an embodiment of the present invention. be. 1... Casing, 2... Main flow path, 3
... Valve seat, 4... Valve body, 5...
・Piston, 5a...Front, 5b...
Back side, 9...Pilot channel, 10...
・Exhaust hole, 11...Solenoid valve, 16...
non-return valve.

Claims (1)

[Scope of utility model registration request] A main flow path and a valve element for opening and closing the main flow path are provided in the valve casing, and the valve element is urged toward the main flow path closing side by a spring, and the valve element is pushed against the spring by introducing pilot pressure. , comprising a pressure-sensitive operating member such as a piston or diaphragm that moves in the direction in which the main flow path is opened,
In the valve device, the pilot flow path for introducing pilot pressure into the pressure-sensitive operating member communicates with the primary side of the main flow path, and includes a solenoid valve that opens and closes the pilot flow path. A valve device characterized by comprising a check valve that is opened by pressure on the primary side of the valve.