JP2846626B2 - Solenoid valve and method of controlling solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve useful for opening and closing a flow path of a low-pressure gas such as city gas or propane gas, and a control method thereof.

[0002]

2. Description of the Related Art A solenoid valve is used as a means for opening and closing a flow path of a low-pressure gas such as city gas or propane gas. A conventional solenoid valve of this type has a structure in which a valve body is moved by one plunger sliding on two coils. That is, a starting current is applied to the first coil to move the plunger in a direction in which the flow path is opened, and then a holding current is applied to the second coil, and the energization of the first coil is stopped. And the position of the plunger is maintained only by the force of the plunger.

[0003]

According to the conventional solenoid valve described above, a current of, for example, several hundred mA must be continuously supplied to the coil in order to maintain the position of the plunger that opens the valve. When this solenoid valve is used to open and close a gas flow path, a predetermined value of current must be supplied to the coil to keep the valve open while the gas is being used. Usually, in the case of gas appliances used at home, batteries are often used as power sources,
The solenoid valve having such a structure has a problem that the battery is not long-lasting due to heavy consumption.

[0004] It is an object of the present invention to provide a solenoid valve which consumes less power than conventional ones and a method of controlling the solenoid valve.

[0005]

According to the first aspect of the present invention, there is provided a solenoid valve which is hermetically sealed with respect to a gas flow path and a flexible partition wall facing the flow path. An air chamber provided with a ventilation hole communicating with the outside air, a valve body attached to the partition to close the flow path and open the gas flow path when moved in a first direction; A first plunger that is housed and connected to the valve body and urged in a direction opposite to the first direction, a starting coil that moves the first plunger in the first direction when energized; A second plunger urged in a direction in which a vent of the air chamber is opened; and a holding coil for driving the second plunger so that the vent is closed by the second plunger when energized. ing.

[0006] The solenoid valve according to the second aspect is the first aspect.
3. The solenoid valve according to claim 1, wherein the starting coil is configured to be connected to the first plunger by a force greater than a force applied by the holding coil to the second plunger.
Is characterized in that the force applied to the plunger is greater.

According to a third aspect of the present invention, in the control method for an electromagnetic valve according to the first aspect, the first plunger is moved in the first direction by energizing the starting coil. Opening the flow path and discharging the air in the air chamber out of the vent hole, energizing the holding coil, closing the vent hole with the second plunger, and closing the first plunger. The position is fixed by a vacuum force, and thereafter, the energization of the starting coil is cut off in a state where the holding coil is energized, thereby maintaining the open state of the flow path.

According to a fourth aspect of the present invention, in the control method for an electromagnetic valve according to the third aspect, energizing the starting coil and the holding coil is performed substantially simultaneously when the flow path is opened. It is characterized by starting.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The solenoid valve 1 of the present embodiment is used to turn on / off relatively low-pressure gas, for example, household city gas or propane gas.
This is used for OFF control, and is used for a home gas stand or the like.

A fluid passage 3 is formed in the valve box 2 in a horizontal direction in the figure. The flow path 3 opens outside the valve box 2 via an inlet 3a and an outlet 3b. An opening / closing hole 4 is provided substantially at the center of the flow path 3. The opening / closing hole 4 is a substantially circular hole that opens in the vertical direction in the figure, and its upper peripheral edge is an edge 5. A substantially disc-shaped rubber valve body 6 having a diameter larger than that of the opening / closing hole 4 is in contact with an edge 5 of an upper peripheral edge of the opening / closing hole 4. The valve 6 is fixed to the center of a diaphragm 7 as a partition. The diaphragm 7 is, for example, a metal plate having a thickness of about 0.05 mm and has flexibility. That is, it is easily deformed when an external force is applied, but returns to its original shape when the external force disappears. The diaphragm 7 is fixed to the valve box 2 around the entire circumference thereof.
The flow path 3 in the valve box 2 is airtightly divided into an upper surface side and a lower surface side of the valve body 6.

The valve element 6 is fixed to a lower end of a cylindrical lower plunger 8. The lower plunger 8 protrudes above the valve box 2 through a hole 2a formed on the upper surface of the valve box 2. A cylindrical housing 9 is fixed to the upper surface of the valve box 2, and a tube 10 communicating with the hole 2 a of the valve box 2 is provided inside the housing 9. A hole 11 is provided at the center of the upper surface of the housing 9 and communicates with the tube 10. The inside of the pipe 10 and the inside of the valve box 2 communicate with each other via the hole 2a. The space inside the valve box 2 above the diaphragm 7 and the space inside the pipe 10 communicating therewith are connected by the diaphragm 7 to the flow path 3.
Is airtight. The space above the diaphragm 7 that is airtight with respect to the flow path 3 is hereinafter referred to as an air chamber 12.

A starting coil 13 for operating the lower plunger 8 is provided below the inside of the housing 9. The starting coil 13 is fixed between the inner wall of the housing 9 and the outer wall of the tube 10. The operating current and voltage of the starting coil 13 are, for example, 800
It is about mA · 3V. The lower plunger 8 is slidably inserted from below into the tube 10 at a position corresponding to the starting coil 13. A fixed core 14 is attached to the tube 10 at a position corresponding to the upper end of the starting coil 13. The space between the fixed core 14 and the tube 10 is airtight. When the activation coil 13 is energized and the lower plunger 8 magnetically attaches to the fixed core 14, the diaphragm 7 is deformed into an upwardly convex shape and the valve body 6
Opens the opening / closing hole 4 and the fluid flows.

The fixed core 14 has ventilation holes 15 penetrating the upper and lower surfaces. The air chamber 12 is provided with the ventilation hole 1.
It communicates with the outside air through 5. Although not shown, fixed core 1
A peripheral projection is provided around the ventilation hole 15 on the upper surface of the fourth member 4. A spring 16 as an urging means is interposed between the fixed core 14 and the lower plunger 8. The spring 16 pushes down the lower plunger 8 and presses the valve body 6 against the edge 5 of the opening / closing hole 4 to close the flow path 3.

The starting coil 1 is provided above the inside of the housing 9.
3, a holding coil 17 is provided coaxially.
The holding coil 17 is fixed between the inner wall of the housing 9 and the outer wall of the tube 10. The holding coil 17 is smaller than the starting coil 13 and its operating current and voltage are, for example, about 2 mA · 3 V.
It is about. The tube 10 at a position corresponding to the holding coil 17
, The upper plunger 18 is movably inserted.
The upper plunger 18 is shorter than the lower plunger 8 and slightly smaller than the length of the holding coil 17, and can move up and down while being inserted into the holding coil 17. A soft seal member 19 made of rubber or the like is provided at a part of the center of the lower surface of the upper plunger 18.
When the holding coil 17 is energized and the upper plunger 18 is attracted to the fixed core 14, the sealing member 19 comes into contact with a circumferential protrusion on the upper surface of the fixed core 14, and closes the ventilation hole 15. A spring 20 as an urging means is interposed between the upper plunger 18 and the fixed core 14. Holding coil 17
When power is not supplied to the upper plunger 18,
Push up.

The operation of the solenoid valve 1 configured as described above will be described. The case where the solenoid valve 1 is opened to flow the fluid will be described. By energizing the starting coil 13, the lower plunger 8 is moved upward and magnetically attached to the fixed core 14. The valve element 6 is lifted together with the lower plunger 8, and the flow path 3 is opened. The diaphragm 7 is deformed into an upwardly convex shape, and the air chamber 1 is deformed.
A part of the air in 2 is discharged out of the ventilation hole 15. Next, by energizing the holding coil 17, the upper plunger 18 is magnetically attached to the fixed core 14 to close the ventilation hole 15. Thereafter, the power supply to the starting coil 13 is stopped while the power supply to the holding coil 17 is maintained. Since the vent hole 15 is kept closed, the lower plunger 8 is held in a state of being lifted upward by the vacuum force.

A case where the flow of fluid is shut off by closing the solenoid valve 1 will be described. When closing the solenoid valve 1, the energization of the holding coil 17 may be stopped. The upper plunger 18 is lifted upward by the urging force of the spring, and the vent hole 15 is opened. Since the air enters the air chamber 12, the upward vacuum force acting on the lower plunger 8 is released, and the lower plunger 8 is depressed by the force of the spring 16 so that the valve 6
Closes the opening / closing hole 4.

Although the operating current of the starting coil 13 is as large as 800 mA, the current is immediately cut off when the valve is opened, and the power is immediately cut off. That is, in this example, the vacuum force is used to maintain the open state of the valve. Therefore, in order to maintain the valve in the raised state and keep the flow path 3 in the open state, continuous operation of the starting coil 13 is required. No need to energize, low power consumption holding coil 17
It is only necessary to energize the. The power consumed by the holding coil 17 is reduced by the use of the vacuum force. For this reason, the consumption of the battery or the like as a power source is less than in the conventional case, and the battery lasts longer.

In the above description of the operation, when the valve is opened, the energizing of the starting coil 13 is performed first, then the energizing of the holding coil 17 is started, and thereafter, the energizing of the starting coil 13 is stopped. However, when the valve is opened, the energization of the starting coil 13 and the holding coil 17 may be started substantially simultaneously. In this case, the force applied by the starting coil 13 to the lower plunger 8 is stronger than the force applied by the holding coil 17 to the upper plunger 18.
As a result, the upper plunger 18 closes the air hole 15 after the air in the air chamber 12 is purged out of the air hole 15 of the fixed core 14. The time for energizing both coils simultaneously may be, for example, about 0.5 seconds. Thereafter, the energization of the starting coil 13 is immediately stopped, and the holding coil 17 is turned off.
Only the energization to is continued. When the valve is closed, the power supply to the holding coil 17 is stopped.

In the above example, if a suitable number of vertical grooves communicating with the upper and lower end surfaces are formed on the peripheral surface of the solid cylindrical lower plunger 8, the air in the air chamber 12 can be easily guided upward. It is easy to escape from the ventilation hole 15 to the outside.

In the above example, the upper plunger 18 is shown as a solid cylindrical member. However, if the upper plunger 18 is a hollow cylindrical shape having an open upper surface, the weight becomes lighter, so that the responsiveness of operation by the coil is further higher than that of the above example. improves. If an appropriate number of vertical grooves communicating with the upper and lower ends are formed on the peripheral surface of the cylindrical upper plunger 18, the air that has escaped from the air chamber 12 can easily escape to the outside of the housing 9.

In the above example, if a filter is provided in the hole 11 of the housing 9 to prevent dust and the like from entering the inside of the housing 9, the operation reliability of the solenoid valve 1 is further improved.

In the above example, the vacuum force generated by closing the vent hole 15 after purging the air chamber 12 opens the valve body 6 against the urging force of the spring 16 and the return force of the diaphragm 7. A degree that can be held in position is required. The smaller the cross-sectional area of the vent hole 15 of the fixed core 14, which is the opening of the air chamber 12, the less air leaks and the easier it is to maintain a vacuum force.

[0023]

According to the present invention, energizing the starting coil to move the first plunger, opening the flow path, discharging air in the air chamber from the vent hole, and further energizing the holding coil. By closing the vent hole with the second plunger, the position of the first plunger is fixed by vacuum force, and then the energizing of the starting coil is cut off while the holding coil is energized. , The following effects can be obtained.

(1) Since the open state of the valve can be held with a small current of the holding coil, the current consumption is small and the battery and the like last longer. (2) It is safe because the valve always closes in case of failure. (3) When an abnormal situation such as an earthquake or an accident occurs, the upper plunger, which has a weak magnetic adhesion, moves due to vibration and air enters the air chamber without turning off the power to the holding coil. It is safe because the flow path is automatically closed. (4) It is safe because the working part using the coil driven by electricity and the side of the valve through which the gas flows are completely separated through the partition wall.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 3 Flow path 6 Valve body 7 Diaphragm as a partition 8 Lower plunger as a first plunger 12 Air chamber 13 Starting coil 15 Vent hole 17 Holding coil 18 Upper plunger as a second plunger

Claims (4)

(57) [Claims] An air chamber provided with a gas flow path, a gas barrier configured to be airtight with respect to the flow path through a flexible partition wall facing the flow path, and having a communication hole with outside air; A valve body that is attached to the partition wall to close the flow path and open the gas flow path when moved in a first direction; and a first valve that is housed in the air chamber and connected to the valve body and connected to the valve body. A first plunger biased in a direction opposite to the first direction, a starting coil for moving the first plunger in the first direction when energized, and a second coil biased in a direction in which a vent of the air chamber opens. An electromagnetic valve comprising: a second plunger; and a holding coil that drives the second plunger so that the vent hole is closed by the second plunger when energized. 2. The solenoid valve according to claim 1, wherein a force applied by the activation coil to the first plunger is greater than a force applied by the holding coil to the second plunger. 3. Energizing the starting coil moves the first plunger in the first direction to open the flow passage and discharges air in the air chamber from the ventilation hole to the outside. By energizing the holding coil, the second plunger closes the vent hole and fixes the position of the first plunger by a vacuum force, and then energizes the starting coil while energizing the holding coil. 2. The method according to claim 1, wherein the open state of the flow path is maintained by cutting. 4. The method according to claim 3, wherein when the flow path is opened, the energization of the starting coil and the holding coil is started substantially simultaneously.