JPH0438137Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pilot type two-port solenoid valve, and more specifically, to a pilot type two-port solenoid valve that prevents the solenoid from being galled by dust. be.

[Prior Art] A pressure acting chamber is defined behind a valve body that opens and closes a main valve seat between an inlet port and an outlet port of a main valve,
The inlet port and the outlet port are communicated with the pressure chamber through an inlet orifice and an outlet orifice having a larger opening area than the inlet orifice, respectively, and fluid is supplied and discharged from the pressure chamber by opening and closing the outlet orifice using a pilot solenoid valve. A pilot-type two-port solenoid valve that opens and closes a valve body is already known without being particularly exemplified.

However, the above-mentioned known solenoid valve has a problem in that when the fluid contains dust, the dust enters the solenoid of the pilot solenoid valve through the inlet orifice, causing galling of the movable iron core.

It is generally known that a filter such as a wire mesh is used as a means to remove dust from a fluid, but the filter is easily clogged and requires frequent replacement. When a solenoid valve is installed, maintenance is troublesome because the valve must be disassembled each time it is replaced.

[Problem to be Solved by the Invention] The problem to be solved by the invention is to provide a pilot type two-port solenoid valve that does not cause galling of the solenoid and is easy to maintain.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a main valve and a pilot solenoid valve, and a valve body that opens and closes a main valve seat between an inlet port and an outlet port of the main valve. A pressure acting chamber is defined behind the inlet port, an outlet port, and an inlet orifice.
An outlet orifice having a larger opening area than the inlet orifice and a flow path communicate with the valve chamber of the pilot solenoid valve, and fluid is supplied and discharged from the pressure action chamber by opening and closing the outlet orifice by the pilot solenoid valve. Pilot type 2 that opens and closes the body
In the port solenoid valve, the dust protection plate provided in the valve chamber of the pilot solenoid valve has an orifice shielding portion having a space between it and the inlet orifice, covering the orifice, and having an outer edge close to the peripheral wall of the valve chamber. It is characterized by

[Operation] Dust in the fluid flowing into the valve chamber of the pilot solenoid valve from the inlet orifice collides with the orifice shielding portion of the dust protection plate provided in the valve chamber.

In this case, since there is a gap between the orifice shield and the inlet orifice, there is no problem with the pilot fluid flowing into the valve chamber, and since the outer edge of the orifice shield is close to the peripheral wall of the valve chamber, Since dust does not enter the solenoid, galling of the solenoid due to dust can be prevented.

Furthermore, unlike a filter, the dust protection plate does not become clogged and therefore does not need to be replaced for a long period of time, making maintenance easy.

[Embodiment] Figures 1 and 2 show an embodiment of the present invention, and this pilot type two-port solenoid valve has a main valve 1 and a pilot solenoid valve 2 that opens and closes the pilot flow path of the main valve.
It is equipped with

The valve body 4 of the main valve 1 includes an inlet port 5, an outlet port 6, and a main valve seat 7 in a flow path that communicates these ports, and a valve body 8 that opens and closes the main valve seat 7 is connected to the valve body A pressure acting chamber 11 is formed in the bonnet 9 behind the valve body 8, which is partitioned by a diaphragm 10.

The diaphragm 10 has a shell 1 on the pressure action chamber side.
3 on the main valve seat side and retaining plate 1 holding the elastic member 14.
5, which are integrated by a guide shaft 16 to constitute the valve body 8, and the guide shaft 16 is guided to a cylindrical portion 17 within the bonnet 9.

The valve chamber 20 of the pilot valve 2 communicates with the inlet port 5 through an inlet orifice 21 that opens toward the solenoid 2a, and with the outlet port 6 and the pressure chamber 11 through channels 22 and 23, respectively. An outlet orifice 24, which is attached to the passage 22 and has a larger opening area than the inlet orifice 21, is opened and closed by a pilot valve body 25.

The dust protection plate 27 sandwiched between the valve body 4 and the outlet orifice 24 in the valve chamber 20 is
An orifice shielding part 27a having a gap with the inlet orifice 21 and having an outer edge close to the circumferential wall of the valve chamber 20, and a radial hole 28 opened in a plane parallel to the circumferential surface of the outlet orifice 24,... It is equipped with

In the pilot valve 2, when the movable iron core is attracted to the fixed iron core by the excitation of the solenoid 2a, the pilot valve body 25 provided on the movable iron core opens the outlet orifice 24, and when the movable iron core returns by de-energizing the solenoid 2a. , the pilot valve body 25 is configured as a well-known solenoid valve for closing the outlet orifice 24.

Next, the operation of the above embodiment will be described.

In FIG. 1, the outlet orifice 24 is closed by the pilot valve body 25, and the pilot fluid pressure flowing into the pressure chamber 11 from the inlet port 5 through the inlet orifice 21 and the flow path 23 causes the valve body 8 to close.
shows the state in which the main valve seat 7 is closed. When the solenoid 2a is excited in this state, the pilot valve body 25 opens the outlet orifice 24, and the pilot fluid in the pressure action chamber 11 flows into the flow path 23.
and flows out through the outlet orifice 24 to the outlet port 6, so that the valve body 8 opens the main valve seat 7 by the fluid pressure from the inlet port 5. In this case, a small amount of fluid flows into the valve chamber 20 from the inlet orifice 21, but since the opening area of the inlet orifice 21 is smaller than that of the outlet orifice 24, this fluid does not flow into the pressure action chamber 11. .

When the solenoid 2a is de-energized, the pilot valve body 25 closes the outlet orifice 24, so pilot fluid flows into the pressure action chamber 11 from the inlet orifice 21, and this pilot fluid pressure causes the valve body 8 to close to the main valve seat. Close 7.

In the opening/closing operation of the main valve 1, the inlet port 5
If the fluid supplied to the solenoid 2a contains foreign matter such as dust, the foreign matter flowing from the inlet orifice 21 toward the solenoid 2a is removed by an orifice shield that covers the inlet orifice 21 and whose outer edge is close to the peripheral wall of the valve chamber 20. Since the foreign matter collides with the portion 27a and is prevented from entering the solenoid 2a, galling of the movable iron core by foreign matter can be prevented.

Furthermore, unlike a filter such as a wire mesh, the dust protection plate 27 does not become clogged and does not need to be replaced for a long period of time, so maintenance is easy.

Furthermore, since the conventional main valve can be used as is, the overall cost can be reduced.

According to an experiment in which silica sand with a diameter of 30 μm and 200 μm was mixed in water, galling occurred in the movable iron core after several operations when the dust protection plate 27 was not used.
When the dust protection plate 27 was used, there was no galling of the movable iron core even after several thousand operations, and no problems such as clogging occurred.

[Effects of the invention] In the pilot type two-port solenoid valve of the present invention, since the dust protection plate provided in the valve chamber of the pilot solenoid valve has an orifice shielding part, foreign matter in the fluid collides with the orifice shielding part. Since intrusion into the solenoid is prevented, there is no galling of the solenoid by dust, and therefore the durability of the valve is improved.

In addition, the dust protection plate mentioned above, which prevents dust from entering or flowing into the solenoid due to collision, does not get clogged unlike the filter, and therefore does not need to be replaced for a long time, so maintenance is easy. It's easy.

Furthermore, since a known main valve can be used as is, it can be made inexpensive.

[Brief explanation of the drawing]

Figure 1 is a vertical sectional view of the main part of the embodiment of the present invention, Figure 2
The figure is an enlarged sectional view of the main part. 1...Main valve, 2...Pilot solenoid valve, 2a...
... Solenoid, 5 ... Inlet port, 6 ... Outlet port, 7 ... Main valve seat, 8 ... Valve body, 11 ... Pressure action chamber, 21 ... Inlet orifice, 24 ... Outlet orifice, 25 ... Pilot valve body, 27...
Dust protection plate.

Claims (1)

[Claims for Utility Model Registration] A pressure acting chamber is provided with a main valve and a pilot solenoid valve, and a pressure acting chamber is defined behind a valve body that opens and closes a main valve seat between an inlet port and an outlet port of the main valve. The port, the outlet port, and the pressure action chamber are communicated with the valve chamber of the pilot solenoid valve through an inlet orifice, an outlet orifice having a larger opening area than the inlet orifice, and a flow path, and the outlet orifice by the pilot solenoid valve is connected to the valve chamber of the pilot solenoid valve. In a pilot type two-port solenoid valve that opens and closes the valve body by supplying and discharging fluid from a pressure action chamber by opening and closing the valve, a dust protection plate installed in the valve chamber of the pilot solenoid valve has a space between it and the inlet orifice. A pilot type two-port solenoid valve, comprising: an orifice shielding portion that covers the orifice and has an outer edge close to a peripheral wall of the valve chamber.