JPH0335544B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a normally open pilot type two-port solenoid valve.

[Prior Art] The inventors of the present invention have previously provided a pilot discharge hole in a fixed manner in a valve body, which operates even when the difference between the primary side pressure and the secondary side pressure is almost zero, and which has a movable iron core. We have developed a special pilot-type two-port solenoid valve that miniaturizes the electromagnetic part and reduces power consumption by opening the pilot valve with a large suction force in the latter half of the suction stroke when the iron is attracted to the fixed iron core. Application No. 60-39070 (Special Publication No. 63-35878),
This is proposed as Japanese Patent Application No. 179918/1983 (Special Patent Application No. 14238/1983).

These solenoid valves are normally closed type in which the main valve always closes the main valve seat, and the same applies to normally open type pilot operated 2 port solenoid valves in which the main valve always opens the main valve seat. There is a need for something that can operate even when the difference between the primary and secondary pressures is almost zero, and has the ability to close the main valve when the suction force between the cores increases. .

[Problems to be Solved by the Invention] The present invention operates even when the difference between the primary side pressure and the secondary side pressure is almost zero, and operates the main valve when the suction force between the iron cores becomes large. The problem to be solved is to obtain an inexpensive normally open pilot type two-port solenoid valve whose electromagnetic portion is reduced in size by closing the valve.

[Means for Solving the Problems] The present invention provides a main valve seat on which the main valve approaches and separates the passage between the inlet port and the outlet port opened in the valve body, and a pilot seat behind the main valve. A pressure acting chamber is provided which communicates with the inlet port and the outlet port through a supply hole and a pilot discharge hole, and the pilot valve closes the pilot discharge hole by driving the movable iron core in the electromagnetic part, thereby causing the main valve to close the main valve. Normally open pilot type 2 with closed seat
In the port solenoid valve, the pilot discharge hole is fixedly provided in the valve body, and the pilot valve, which approaches and separates from the pilot valve seat of the pilot discharge hole, is biased in the valve closing direction by a travel spring, and the movable iron core and The above-mentioned problem is solved by providing the valve in a holder that is integrally driven and supporting the holder with a support spring that has a biasing force in a direction to move the holder away from the pilot valve seat.

[Operation] When the electromagnetic part is energized, if there is a certain degree of pressure difference between the primary pressure and the secondary pressure, the movable core is attracted by the fixed core, and the pilot in the holder, which is driven together with the fixed core, is activated. Since the valve closes the pilot valve seat, the fluid pressure in the pressure chamber causes the main valve to close the main valve seat.

When the differential pressure between the primary pressure and the secondary pressure is almost zero, the movable core is further attracted to the fixed core, the holder presses the support, and the main valve closes the main valve seat. In this case, the movable iron core closes the main valve after the holder is attracted until it comes into contact with the leg of the support, and the suction force between the iron cores becomes large. This is compared to the case where the main valve is closed from the beginning of the stroke of the movable iron core. As a result, the attractive force of the electromagnetic part can be reduced.

When the electromagnetic section is de-energized, the holder and movable core are stroked in the opposite direction by the urging force of the support spring, and the pilot valve opens the pilot valve seat, so that the main valve opens the main valve seat.

[Embodiment] FIG. 1 shows a first embodiment of the present invention, in which a valve body 1
is equipped with a main valve seat 4 in the inlet port 2, the outlet port 3, and the flow path between both ports 2 and 3, and the main valve 5 facing the main valve seat 4 is connected to the inside of the valve body 1 by a diaphragm 5a. The pressure acting chamber 6 is formed behind the support.

The pressure action chamber 6 communicates with the inlet port 2 through a small diameter pilot supply hole 7 formed in the diaphragm 5a, and also communicates with the inlet port 2 through a passage 8 provided in the valve body 1.
The pilot chamber 9, which communicates with the pressure acting chamber 6 and forms a part of the pressure acting chamber 6, is connected by a pilot discharge hole 11 communicating with a pilot valve seat 10 fixedly opened in the chamber 9. , and communicates with the outlet port 3. The pilot discharge hole 11 is formed to have a larger diameter than the pilot supply hole 7.

The shell plate 13 fixed to the diaphragm 5a is urged by a lift spring 14 contracted in the pressure chamber 6 so as to come into contact with the abutting shoulder of the pressure chamber 6. Main valve 5
is always kept in an open state separated from the main valve seat 4 by the main valve stroke VS.

In the upper part of the pilot chamber 9 in the valve body 1,
The fixed iron core 2 is
The electromagnetic part 2 has a movable iron core 23 attached to it.
0 is fixed. A valve rod 2 supported by a support spring 24 and striking the movable core 23 to separate it from the fixed core 22
5 extends into the pilot chamber 9 through the through hole of the fixed iron core 22, and is provided with a holder 26 located in the pilot chamber 9 at one end thereof. This holder 2
In the pilot valve housing chamber 27 formed in the 6,
The pilot valve seat 1 is moved by the travel spring 28.
A pilot valve 29 biased in the zero direction is slidably inserted, and the pilot valve 29
An engaging portion on the mouth edge of the pilot valve housing chamber 27 prevents the pilot valve from escaping. The pilot valve 29 is disposed at a position facing the pilot valve seat 10.

The pilot chamber 9 is provided with an annular plate 32 that can be engaged with the stepped portion 26a on the outer periphery of the holder 26, and the plate 32 is configured to open the pilot chamber 9 by the urging force of an opening spring 33 contracted in the pilot chamber 9. It is brought into contact with the inner surface of chamber 9. Further, a support spring 24 having a smaller urging force than the release spring 33 is installed between the plate 32 and the holder 26, and the urging force of the support spring 24 causes the fixed iron core 22 and the movable iron core 23 to An adsorption stroke AS, which is larger than the main valve stroke VS, is formed in between. In this case, the support spring 24 may have a small urging force that only supports the valve stem 25, the holder 26, and the movable core 23.

Therefore, in a state where the movable iron core 23 is spaced apart from the fixed iron core 22, the stepped portion 2 of the holder 26
6a and the plate 32 have a travel amount approximately equal to the main valve stroke VS, and between the pilot valve 29 and the pilot valve seat 10, a pilot stroke PS smaller than the main valve stroke VS is formed.
is formed.

The support 16, which is slidably provided in the pressure application chamber 6, is provided with an elastic material 17 at the tip that contacts the main valve 5, and is extended into the pilot chamber 9 through the partition wall of the pressure application chamber 6. A gap slightly larger than the pilot stroke PS is formed between the legs 16a, . . . and the holder 26.

Next, the operation of the first embodiment will be explained.

In FIG. 1, the electromagnetic coil 21 is in a non-energized state, and the pressure fluid that has flowed into the pressure action chamber 6 through the supply hole 7 of the diaphragm 5a is transferred to the pilot valve seat 1.
Since the diameter of the supply hole 7 is smaller than the diameter of the discharge port 11, the pressure in the pressure action chamber 6 is equal to the pressure on the outlet port 3 side. is almost equivalent to holder 2.
6. The valve stem 25 and the movable core 22 are moved upward by the urging force of the support spring 24. Therefore, the main valve 5 opens the main valve seat 4 by the biasing force of the lift spring 14, and the pressure fluid from the inlet port 2 flows out through the main valve seat 4 to the outlet port 3. .

When the electromagnetic coil 21 is energized in this state, the movable core 23 compresses the support spring 24, which has a smaller urging force than the release spring 33, due to the attractive force between the cores, and slides by the pilot stroke PS. Since the pilot valve 29 closes the pilot valve seat 10, the primary pressure and the
When there is a certain degree of differential pressure in the next side pressure, the fluid pressure in the pressure action chamber 6 increases, and the main valve 5 moves to the main valve seat 4.
will be closed. In this case, the support spring 24
is a small urging force that is sufficient to support the movable core 22 and the holder 26, so the electromagnetic section 20 does not require a large attractive force.

When the differential pressure between the primary side pressure and the secondary side pressure is almost zero, the movable iron core 23 is connected to the support spring 24.
The travel spring 28 is further compressed and the holder 26 is moved to the leg 16 of the support 16.
a, . Above lift spring 1
The compression in step 4 is performed after the movable core 23 has made a stroke that is slightly larger than the pilot valve stroke PS, so the suction force between the cores has increased, so if the movable core 23 compresses the lift spring from the beginning of the stroke. Compared to the electromagnetic part 20
can be downsized. FIG. 3A shows the relationship between the attractive force acting on the movable core of the electromagnetic section 20 and the force of each spring.

During the above-mentioned stroke of the movable iron core 23, the pilot valve 29 slides in the pilot valve housing chamber 27 against the biasing force of the travel spring 28, so it does not interfere with the stroke of the movable iron core, and the main valve 5 After closing the main valve seat 4, the movable core 23 is attracted to the fixed core 22 by compressing the elastic material 17 at the tip of the support 16.

Further, near the end of the stroke of the movable core 23, the step portion 26a engages with the plate 32, and the opening spring 33 is compressed by a stroke amount corresponding to the pilot valve stroke PS.

When the power to the electromagnetic coil 21 is cut off, the movable iron core 2
3 is stroked in the opposite direction to the above case due to the biasing force of the release spring 33 and the biasing force of the support spring 24 due to the engagement between the plate 32 and the stepped portion 26a of the holder 26, and the pilot valve 29 is opened. Since the pilot valve seat 10 is opened,
The fluid pressure in the pressure application chamber 6 decreases, and the main valve 5 opens the main valve seat 4 due to the fluid pressure in the inlet port 2 acting on the lift spring 14 and the main valve 5.

It should be noted that the lift spring 14 is not limited to the one that is compressed and installed within the pressure action chamber 6 as shown in the drawings, but may be placed at another appropriate position, or may be a tension spring that lifts the valve body 5 toward the pressure action chamber 6 side. can.

The electromagnetic valve of the first embodiment applies the support spring force, the travel spring force, and the release spring force in sequence according to the stroke of the movable core, so that the resultant force of these spring forces is applied from the beginning of the stroke of the movable core. Compared to things,
The attraction force of the electromagnetic part 20 can be reduced, and a small electromagnetic part can be used.

FIG. 2 shows a second embodiment of the present invention, in which the elastic material 17 is different from the electromagnetic valve of the first embodiment.
The elastic force of the release spring 33 is increased, and the release spring 33 is
By providing this function, the plate 32 and the release spring 33 are omitted, and the support spring 36 is compressed between the partition wall of the pressure action chamber 6 and the step portion 26a of the holder 26.

Since the other configurations in the second embodiment are the same as those in the first embodiment, the same or corresponding parts in the drawings are denoted by the same reference numerals, and detailed description thereof will be omitted. Further, the relationship between the attractive force acting on the movable core of the electromagnetic section 20 and the force of each spring is as shown in FIG. 3B.

[Effects of the Invention] The solenoid valve of the present invention closes the main valve when the attraction force of the electromagnetic part becomes large during the attraction stroke of the movable iron core, so the solenoid part can be made smaller and the power consumption can be reduced. be able to.

Furthermore, in the present invention, since the main valve is pressed by the support, the valve can be opened and closed even when the pressure difference between the primary side and the secondary side is small and almost zero. Furthermore, since the pilot discharge hole is fixedly provided in the valve body, the valve body having a complicated shape can be used in common with a normally closed type valve, and the solenoid valve can be constructed at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of the first embodiment of the present invention, Fig. 2 is a longitudinal sectional front view of the second embodiment, and Fig. 3 shows the relationship between the attraction force of the electromagnetic operating section and the main valve closing force. In the diagram, A shows the case of the first embodiment, and B shows the case of the second embodiment. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Inlet port, 3... Outlet port, 4... Main valve seat, 5... Main valve, 7... Pilot supply hole, 10... Pilot valve seat, 11...
...Pilot discharge hole, 14...Lift spring, 16...Support, 16a...Leg, 20...
Electromagnetic part, 23...Movable iron core, 26...Holder, 2
8... Travel spring, 29... Pilot valve, 24, 36... Support spring.

Claims (1)

[Scope of Claims] 1. A main valve seat is provided in the passage between the inlet port and the outlet port opened in the valve body, and the main valve seat is provided on which the main valve approaches and separates, and a pilot supply hole and a pilot discharge hole are provided behind the main valve. Therefore, a pressure acting chamber communicating with the inlet port and the outlet port is provided, and the pilot valve closes the pilot discharge hole by driving the movable iron core in the electromagnetic part, thereby causing the main valve to close the main valve seat. In a normally open pilot type two-port solenoid valve, the pilot discharge hole is fixedly provided in the valve body, and the pilot valve, which approaches and separates from the pilot valve seat of the pilot discharge hole, is biased in the valve closing direction by a travel spring. The holder is provided in a holder that is driven integrally with the movable iron core, and the holder is supported by a support spring that has a biasing force in the direction of separating it from the pilot valve seat, and the holder is slidably attached to the main valve by the valve body. was guided,
A normally open pilot type two-port solenoid valve characterized in that its legs abut opposing supports on the holder at an interval slightly larger than the stroke of the pilot valve.