JP7096127B2 - Electric gas valve device - Google Patents

Description

The present invention relates to an electric gas valve device installed in a gas supply path to a burner.

Conventionally, as this type of electric gas valve device, an electromagnetic safety valve, a flow control valve, an operation rod driven axially via an interlocking mechanism by an electric motor, and a space inside the valve casing are provided in the valve casing. A valve seat member that is movable in the axial direction and is partitioned between a primary gas chamber on one axial direction and a gas chamber on the secondary side in the axial direction is provided (see, for example, Patent Document 1). Here, with one axial direction as the forward direction and the other axial direction as the return direction, the electromagnetic safety valve faces the safety valve valve seat facing the primary gas chamber provided in the valve seat member and the safety valve valve seat. A valve body for the safety valve, a valve spring that urges the valve body for the safety valve to be seated on the valve seat for the safety valve, and a suction piece connected to the valve body for the safety valve via a valve shaft extending in the forward direction. The flow control valve is provided with an electromagnet facing the suction piece, and the flow control valve moves in the axial direction integrally with the valve seat for the control valve facing the secondary gas chamber provided in the valve seat member and the operation rod. It is equipped with a valve body for a control valve that can be seated on the valve seat for the control valve. Further, in the valve casing, a valve seat stopper for stopping the movement of the valve seat member in the recovery direction at a predetermined recovery end position and a valve seat spring for urging the valve seat member in the recovery direction are provided. ing.

In the above-mentioned conventional example, the control valve valve body is seated on the control valve valve seat by rotating the electric motor in the normal direction to move the operation rod in the forward movement direction, and the valve seat member is moved forward from the return end position. It is pushed in the direction of movement, the valve seat for the safety valve is brought into contact with the valve body for the safety valve, and the valve body for the safety valve is pushed against the urging force of the valve spring to the valve opening position where the attracted piece abuts on the electromagnet. By energizing the electromagnet in this state, the valve body for the safety valve is attracted and held at the valve opening position. After that, by reversing the electric motor and moving the operation rod in the recovery direction, the valve seat member is moved in the recovery direction, and the safety valve valve seat is separated from the safety valve valve body which is attracted and held at the valve opening position. The electromagnetic safety valve is opened, and the control valve valve body is separated from the control valve seat by further movement of the operation rod in the recovery direction after the valve seat member reaches the recovery end position. , The gas supply to the burner is gradually increasing.

Further, the flow rate control valve has a bypass path for flowing gas from the primary side gas chamber to the secondary side gas chamber even when the control valve body is seated on the control valve seat. Here, when the amount of gas supplied to the burner is reduced to the minimum amount specified by the bypass path during burner combustion, the electric motor is used for the control valve for the control valve of the valve seat member located at the return end position. If the valve body is stopped at the rotational position where it sits, the electric motor is used before the control valve body is seated on the control valve seat due to the dimensional tolerance of the valve seat member and the position tolerance of the valve seat stopper. May stop and the gas supply to the burner may not be reduced to the minimum specified by the bypass path. Therefore, conventionally, when the amount of gas supplied to the burner is reduced to the minimum amount specified by the bypass path during burner combustion, the electric motor is adjusted to the valve seat for the control valve of the valve seat member located at the return end position. The valve body is rotated forward to a second rotation position deviated by a predetermined angle in the normal rotation direction from the first rotation position, which is the rotation position where the valve body is seated.

However, this causes the following problems. That is, in the conventional example, when the electric motor is rotated forward to the second rotation position, the control valve valve body is seated on the control valve valve seat of the valve seat member located at the return end position, and then further forward. It moves in the direction of movement, and the valve seat member is pushed by the adjusting valve body and moves in the direction of forward movement. Then, due to this movement, the volume of the secondary gas chamber expands, the gas pressure in the secondary gas chamber temporarily drops, and the amount of gas supplied to the burner temporarily undershoots to an amount below the minimum amount. However, it may cause a misfire.

Japanese Unexamined Patent Publication No. 2018-13251

In view of the above points, it is an object of the present invention to provide an electric gas valve device capable of preventing misfire when the gas supply amount to the burner is reduced to the minimum amount during burner combustion.

In order to solve the above problems, the present invention is an electric gas valve device interposed in a gas supply path to a burner, in which an electromagnetic safety valve, a flow control valve, and an electric motor are interlocked in the valve casing. An axially movable valve seat member that partitions the space inside the valve casing between the operation rod driven axially via the mechanism and the primary gas chamber on one axial side and the secondary gas chamber on the other axial direction. The electromagnetic safety valve is provided with a safety valve valve seat facing the primary gas chamber provided in the valve seat member and a safety valve valve seat with one axial direction as the forward direction and the other axial direction as the return direction. The valve body for the safety valve facing the valve body, the valve spring that urges the valve body for the safety valve in the recovery direction to sit on the valve seat for the safety valve, and the valve body for the safety valve are connected via a valve shaft extending in the forward direction. A suction piece and an electromagnet facing the suction piece are provided, and the flow control valve moves in the axial direction integrally with the valve seat for the control valve facing the secondary gas chamber provided in the valve seat member and the operation rod. A control valve valve body that can be seated on the control valve valve seat and a bypass path that allows gas to flow from the primary gas chamber to the secondary gas chamber even when the control valve valve body is seated on the control valve valve seat. In the valve casing, there is a valve seat stopper that stops the movement of the valve seat member in the recovery direction at a predetermined recovery end position, and a valve seat spring that urges the valve seat member in the recovery direction. The valve seat for the control valve is seated on the valve seat for the control valve by rotating the electric motor in the normal direction to move the operation rod in the forward direction, and the valve seat member is moved in the forward direction from the position of the return end. The safety valve valve seat is brought into contact with the safety valve valve body, and the safety valve valve body is pushed against the urging force of the valve spring to the valve opening position where the attracted piece abuts on the electromagnet. By energizing the electromagnet in this state, the valve body for the safety valve is attracted and held at the valve opening position, and then the valve seat member is moved in the recovery direction by reversing the electric motor and moving the operation rod in the recovery direction. The valve seat for the safety valve is separated from the valve body for the safety valve that is attracted and held at the valve opening position to open the electromagnetic safety valve, and further operation rod after the valve seat member reaches the return end position. By moving in the return direction, the valve body for the control valve is separated from the valve seat for the control valve so that the amount of gas supplied to the burner gradually increases, and the amount of gas supplied to the burner is bypassed during burner combustion. When narrowing down to the minimum amount specified in, the electric motor is moved from the first rotation position, which is the rotation position where the control valve valve body is seated on the control valve seat of the valve seat member located at the return end position. For those that rotate forward to the second rotation position that is deviated by a predetermined angle in the normal rotation direction A diaphragm facing the secondary gas chamber is provided, and a back pressure chamber separated from the secondary gas chamber is defined by the diaphragm, and ventilation is provided to communicate the secondary gas chamber and the back pressure chamber. A passage is provided, and the ventilation passage is characterized by having a ventilation resistance such that the gas pressure in the back pressure chamber changes with a response delay after the gas pressure in the secondary gas chamber changes.

According to the present invention, when the electric motor rotates forward beyond the first rotation position, the volume of the secondary gas chamber is expanded due to the movement of the valve seat member in the forward movement direction from the return end position. Even if the gas pressure in the secondary gas chamber (secondary gas pressure) decreases, the gas pressure in the back pressure chamber does not immediately decrease from the secondary gas pressure before the decrease due to the ventilation resistance of the ventilation path, so the back pressure Due to the differential pressure between the gas pressure in the chamber and the gas pressure in the secondary gas chamber, the diaphragm is displaced in the direction of reducing the volume of the secondary gas chamber. Therefore, even if the valve seat member moves in the forward movement direction from the return end position, the volume of the secondary gas chamber does not expand to the left. As a result, the volume of the secondary gas chamber when the electric motor is rotated forward beyond the first rotation position to the second rotation position during burner combustion to reduce the gas supply amount to the burner to the minimum amount. It is possible to suppress undershooting of the gas supply amount to an amount below the minimum amount due to the expansion, and it is possible to prevent misfire.

When the diaphragm is displaced in the direction of reducing the volume of the secondary gas chamber, the volume of the back pressure chamber is expanded, the gas pressure in the back pressure chamber is reduced, and the displacement of the diaphragm in the above direction is suppressed. , There is a risk that it will not be possible to sufficiently prevent the volume expansion of the secondary gas chamber. Therefore, in the present invention, the diaphragm is arranged so as to face the end of the secondary gas chamber on the recovery direction side, the valve seat member is connected to the diaphragm, and the diaphragm is axially together with the valve seat member. It is desirable to displace to. According to this, when the valve seat member moves from the return end position in the forward movement direction, the diaphragm is displaced together with the valve seat member in the forward movement direction, that is, in the direction of reducing the volume of the secondary gas chamber. However, it is possible to reliably prevent the volume of the secondary gas chamber from expanding. Therefore, the certainty of preventing misfire when the gas supply amount to the burner is reduced to the minimum amount is improved.

By the way, it is possible to provide the ventilation path in the valve casing, but this increases the processing cost of the ventilation path. Therefore, in the present invention, it is desirable that the ventilation path is composed of an orifice hole formed in the diaphragm. According to this, the processing cost of the ventilation path is almost zero, and the cost can be reduced.

The cut side view of the electric gas valve apparatus of 1st Embodiment of this invention. An exploded perspective view of an interlocking mechanism provided in the electric gas valve device of the first embodiment. (A) (b) (c) A cut side view of a main part showing the operation of the electric gas valve device of the first embodiment. The cut side view of the electric gas valve device of the 2nd Embodiment of this invention. The cut side view of the main part of the electric gas valve apparatus of 2nd Embodiment when the electric motor is rotated forward to the 2nd rotation position.

Referring to FIG. 1, reference numeral A is an electric gas valve device according to an embodiment of the present invention, which is interposed in a gas supply path G to a burner B provided on a stove. The gas valve device A includes a valve casing 1 having a gas inlet 1a and a gas outlet 1b connected to the burner B. Inside the valve casing 1, an electromagnetic safety valve 2, a flow control valve 3, an operation rod 6 driven axially by an electric motor 4 including a stepping motor and the like via an interlocking mechanism 5, and a valve casing 1 are contained. A valve seat member 7 that is movable in the axial direction and partitions the space between the primary gas chamber 11 in the axial direction communicating with the gas inlet 1a and the secondary gas chamber 12 in the axial direction communicating with the gas outlet 1b. Is provided. The electric motor 4 is mounted on the outer end of the box 13 which is attached to the other end of the valve casing 1 in the axial direction so as to surround the interlocking mechanism 5.

The electromagnetic safety valve 2 has a safety valve valve seat 21 facing the primary gas chamber 11 provided in the valve seat member 7 and a safety valve valve seat 21 with one axial direction as the forward direction and the other axial direction as the return direction. The safety valve valve body 22 facing the safety valve, the valve spring 23 that urges the safety valve valve body 22 in the recovery direction to sit on the safety valve valve seat 21, and the valve shaft extending in the forward movement direction to the safety valve valve body 22. A suction piece 24 connected via the 22a and an electromagnet 25 facing the suction piece 24 are provided. Then, the safety valve valve body 22 is opened by energizing the electromagnet 25 in a state where the suction piece 24 is pushed against the valve spring 23 to the valve opening position where the suction piece 24 abuts on the electromagnet 25. It is designed to be sucked and held at the position. Further, when a misfire is detected by the flame detection element (not shown) attached to the burner B, or when a fire extinguishing operation is performed by pushing the point fire extinguishing button 9 described later into the fire extinguishing position, the energization of the electromagnet 25 is stopped. The safety valve valve body 22 is returned to the valve closing position seated on the safety valve valve seat 21 by the valve spring 23, and the electromagnetic safety valve 2 is closed.

In the valve casing 1, a tubular protrusion formed on the inner surface of the valve casing 1 that stops the movement of the valve seat member 7 in the recovery direction at a predetermined return end position where the safety valve valve body 22 can be seated. A valve seat stopper 71 and a valve seat spring 72 that urge the valve seat member 7 in the recovery direction and elastically hold the valve seat member 7 at the position of the recovery end are provided. It should be noted that the valve seat member 7 is provided with a plurality of leg portions 7a projecting from the peripheral portion of the control valve seat 31 to be described later in the recovery direction, and these leg portions 7a are valved at the recovery end position. It abuts on the seat stopper 71. Further, a belfram 73 is provided on the outside of the valve seat member 7 in order to prevent gas from flowing between the primary gas chamber 11 and the secondary gas chamber 12.

The flow rate control valve 3 includes a control valve valve seat 31 facing the secondary gas chamber 12 provided in the valve seat member 7, and a control valve valve body 32 that moves in the axial direction integrally with the operation rod 6. I have. The control valve valve body 32 is inserted into the valve hole 31a from the reaction direction and the closing valve portion 32a that can be seated in the control valve valve seat 31 so as to close the valve hole 31a opened in the control valve valve seat 31. It has a possible needle portion 32b. Further, the flow rate control valve 3 is provided with a bypass path 33 for flowing gas from the primary side gas chamber 11 to the secondary side gas chamber 12 even when the closing valve portion 32a is seated on the control valve seat 31. In the present embodiment, the bypass path 33 is formed in the valve body 32 for the control valve, but it is also possible to form the bypass path 33 in the valve seat member 7. Further, in the present embodiment, the control valve valve body 32 is integrally formed with the operation rod 6, but the control valve valve body 32 may be separated from the operation rod 6 and attached to the operation rod 6. good.

With reference to FIG. 2, the interlocking mechanism 5 engages with a cylindrical cam body 54 concentric with the operation rod 6 driven to be rotated by an electric motor 4 and a spiral cam groove 54a formed in the cam body 54. The operation rod 6 has a pin 55 fixed to the operation rod 6, and the operation rod 6 moves in the forward direction and the reverse direction by the axial thrust acting from the cam groove 54a through the pin 55 in the forward rotation and the reverse rotation of the cam body 54. It is composed of a cam mechanism that moves in the direction. Between the electric motor 4 and the cam body 54, a reduction gear train 51 incorporated in the motor case, a rotary shaft 52 on the output side of the reduction gear train 51, and a connection connecting the rotary shaft 52 and the cam body 54 are connected. A child 53 is provided. The connector 53 has a non-circular hole 53a that fits into the rotating shaft 52 having a non-circular cross section, and rotates together with the rotating shaft 52. Further, the connector 53 is provided with a projecting piece portion 53b that engages with a notch portion 54b formed at the end of the cam body 54 on the recovery direction side to transmit a rotational force. A guide cylinder 56 extending in the recovery direction from the valve casing 1 is inserted into the cam body 54. A long hole 56a long in the axial direction is formed in the guide cylinder 56, and a pin 55 is slidably engaged with the long hole 56a in the axial direction. Further, a cam spring 58 is provided to urge and hold the end of the cam body 54 in the forward direction in a state of being in contact with the cam stopper 57 formed of the end wall of the box 13.

Further, a controller 8 for controlling the electric gas valve device A is provided. An operation signal from the point fire extinguishing button 9 provided on the operation panel of the stove is input to the controller 8. The point fire extinguishing button 9 is a push-push type, and is displaced to an ignition position protruding from the surface of the operation panel portion by once pushing in from a fire extinguishing position substantially flush with the surface of the operation panel portion and releasing the push-in. It can be rotated to adjust the heating power. Then, when the ignition operation for projecting the point fire extinguishing button 9 to the ignition position is performed, the controller 8 rotates the electric motor 4 in the normal direction via the motor drive circuit 41. According to this, the operation rod 6 moves in the forward movement direction via the interlocking mechanism 5, and first, the block valve portion 32a of the control valve valve body 32 is located at the return end position where the valve seat stopper 71 stops. The valve seat member 7 is seated on the control valve seat 31, and thereafter, the valve seat member 7 is pushed by the control valve valve body 32 and moves in the forward movement direction. Then, the safety valve valve seat 21 comes into contact with the safety valve valve body 22, and the safety valve valve body 22 is pushed to the valve opening position (state shown in FIG. 3A). In this state, the electromagnet 25 is energized to attract and hold the safety valve valve body 22 at the valve opening position. After that, the electric motor 4 is reversed to move the operation rod 6 in the return direction, and the igniter (not shown) is energized. At this time, the valve seat member 7 moves in the recovery direction following the operation rod 6 to the recovery end position, and separates from the safety valve valve body 22 in which the safety valve valve seat 21 is attracted and held at the valve opening position. , The electromagnetic safety valve 2 is opened, and the gas supply to the burner B is started. After that, the control valve valve body 32 is further moved in the recovery direction with respect to the valve seat member 7 restrained at the return end position, the block valve portion 32a is separated from the control valve valve seat 31, and the burner B is moved. Gradually increase the gas supply and ignite the burner B. After the burner is ignited, the control valve valve body 32 moves in the forward movement direction, and the control valve valve body 32 (to be exact, the closing valve) is attached to the control valve valve seat 31 of the valve seat member 7 located at the return end position. When the portion 32a) is seated (state of FIG. 3B), the gas flows only through the bypass path 33, and the amount of gas supplied to the burner B becomes the minimum amount.

However, if the electric motor 4 is stopped at the rotational position where the control valve valve body 32 is seated on the control valve seat 31 of the valve seat member 7 located at the return end position, the valve seat member 7 may be stopped. Due to dimensional tolerances, position tolerances of the valve seat stopper 71, etc., the electric motor 4 stops before the control valve valve body 32 is seated on the control valve valve seat 31, and the gas supply amount to the burner B is reduced to the bypass path 33. It may not be possible to squeeze to the minimum amount specified in. Therefore, when the thermal power indicated by the point fire extinguishing button 9 is changed to the minimum thermal power during burner combustion and the amount of gas supplied to the burner B is reduced to the minimum amount specified by the bypass path 33, the electric motor 4 is used. A second rotation deviated by a predetermined angle in the normal rotation direction from the first rotation position, which is the rotation position where the control valve valve body 32 is seated on the control valve seat 31 of the valve seat member 7 located at the return end position. I try to rotate it to the position.

However, the valve seat member 7 is pushed by the valve body 32 for the control valve in the normal rotation from the first rotation position to the second rotation position of the electric motor 4, and the valve seat member 7 moves in the forward movement direction from the return end position. As a result, the volume of the secondary gas chamber 12 expands, the gas pressure in the secondary gas chamber 12 temporarily drops, and the amount of gas supplied to the burner B temporarily falls below the minimum amount. It may shoot and misfire.

Therefore, in the present embodiment, a diaphragm 14 facing the secondary gas chamber 12 is provided, and the back pressure chamber 15 partitioned from the secondary gas chamber 12 by the diaphragm 14 is defined. Specifically, the diaphragm 14 is arranged so as to face the end of the secondary gas chamber 12 on the return direction side, and the inner peripheral edge portion 14a of the diaphragm 14 is fitted onto the outer periphery of the end portion of the valve seat stopper 71. The back pressure chamber 15 is defined around the valve seat stopper 71. The inner peripheral edge portion 14a of the diaphragm 14 is pressed by a spring 141 interposed between the diaphragm 14 and the valve seat member 7 so as not to come out of the valve seat stopper 71.

Further, the secondary gas chamber 12 and the back pressure chamber 15 are ventilated so that the gas pressure in the back pressure chamber 15 changes with a response delay after the gas pressure in the secondary gas chamber 12 changes. It is communicated through a ventilation passage 16 having resistance. It is possible to provide the ventilation passage 16 in the valve casing 1, but this increases the processing cost of the ventilation passage 16. Therefore, in the present embodiment, the ventilation passage 16 is composed of an orifice hole formed in the diaphragm 14. Specifically, the inner peripheral edge portion 14a of the diaphragm 14 is positioned at one position in the circumferential direction of the end face facing the recovery direction of the inner peripheral edge portion 14a to form a groove portion 14b communicating with the back pressure chamber 15. A ventilation path 16 composed of an orifice hole is formed so as to communicate the groove portion 14b and the secondary gas chamber 12. If the ventilation passage 16 is formed in the diaphragm 14 in this way, the processing cost of the ventilation passage 16 is almost zero, and the cost can be reduced.

According to the above configuration, when the electric motor 4 rotates forward beyond the first rotation position to the second rotation position, the valve seat member 7 moves from the return end position as shown in FIG. 3C. The gas pressure (secondary gas pressure) in the secondary gas chamber 12 decreases due to the movement in the forward movement direction and the accompanying expansion of the volume of the secondary gas chamber 12. On the other hand, the gas pressure in the back pressure chamber 15 does not immediately decrease from the secondary gas pressure before the decrease due to the ventilation resistance of the ventilation path 16. Therefore, due to the differential pressure between the gas pressure in the back pressure chamber 15 and the gas pressure in the secondary gas chamber 12, the diaphragm 14 moves forward as shown by the solid line from the state shown by the virtual line in FIG. 3 (c). It is displaced in the direction, that is, in the direction of reducing the volume of the secondary gas chamber 12. Therefore, even if the valve seat member 7 moves in the forward movement direction from the return end position, the volume of the secondary gas chamber 12 does not expand to the left. As a result, when the electric motor 4 is rotated forward beyond the first rotation position to the second rotation position during burner combustion to reduce the gas supply amount to the burner B to the minimum amount, the secondary gas chamber is used. It is possible to prevent the gas supply amount from undershooting to an amount lower than the minimum amount due to the volume expansion of the twelve, and it is possible to prevent misfire.

Next, the second embodiment shown in FIGS. 4 and 5 will be described. The basic structure of the second embodiment is not particularly different from that of the first embodiment, and the same members and parts as those of the first embodiment are designated by the same reference numerals as above.

Here, in the case of the first embodiment, when the diaphragm 14 is displaced in the direction of reducing the volume of the secondary gas chamber 12 (forward direction), the volume of the back pressure chamber 15 is expanded and the back pressure chamber 15 is expanded. There is a risk that the gas pressure inside will decrease, the displacement of the diaphragm 14 in the forward direction will be suppressed, and it will not be possible to sufficiently prevent the volume expansion of the secondary gas chamber 12. Therefore, in the second embodiment, the valve seat member 7 is connected to the diaphragm 14 arranged so as to face the end of the secondary gas chamber 12 on the recovery direction side, and the diaphragm 14 is connected to the valve seat member 7. It is designed to be displaced in the axial direction together. Specifically, the inner peripheral edge portion 14a of the diaphragm 14 is opposed to the end surface of the valve seat stopper 71, and the tip end portion of each leg portion 7a of the valve seat member 7 is inserted and locked to the inner peripheral edge portion 14a to lock the diaphragm. The valve seat member 7 is connected to 14.

According to the second embodiment, when the electric motor 4 rotates forward beyond the first rotation position to the second rotation position and the valve seat member 7 moves in the forward direction from the return end position. As shown in FIG. 5, the diaphragm 14 is displaced together with the valve seat member 7 in the forward movement direction, that is, in the direction of reducing the volume of the secondary gas chamber 12, and the volume of the secondary gas chamber 12 is expanded. It can be surely prevented. Therefore, the certainty of preventing misfire when the gas supply amount to the burner B is reduced to the minimum amount is improved.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the first embodiment, the diaphragm 14 is arranged so as to face the end of the secondary gas chamber 12 on the recovery direction side, but it is a part of the peripheral surface of the secondary gas chamber 12. An opening is formed in the portion of the valve casing 1 and the diaphragm is arranged so as to cover the opening, and the diaphragm cover is arranged on the back side of the diaphragm to draw a back pressure chamber between the diaphragm and the diaphragm cover. It is also possible to do so.

Further, in the above embodiment, the interlocking mechanism 5 is composed of a cam mechanism having a tubular cam body 54, but the interlocking mechanism can also be configured by a feed screw mechanism. Further, the electric motor may be arranged so as to be orthogonal to the valve casing in the axial direction, and the interlocking mechanism may be composed of a rack pinion mechanism consisting of a rack connected to the operation rod and a motor-driven pinion that meshes with the rack. It is possible. Further, the present invention can be similarly applied to an electric gas valve device interposed in a gas supply path to a burner other than a burner for a stove.

A ... Electric gas valve device, B ... Burner, G ... Gas supply path, 1 ... Valve casing, 11 ... Primary gas chamber, 12 ... Secondary gas chamber, 14 ... Diaphragm, 15 ... Back pressure chamber, 16 ... Vent path (oriental hole), 2 ... electromagnetic safety valve, 21 ... safety valve valve seat, 22 ... safety valve valve body, 22a ... valve shaft, 23 ... valve spring, 24 ... suction piece, 25 ... electromagnet, 3 ... flow control valve , 31 ... Control valve valve seat, 32 ... Control valve valve body, 33 ... Bypass path, 4 ... Electric motor, 5 ... Interlocking mechanism, 6 ... Operation rod, 7 ... Valve seat member, 71 ... Valve seat stopper, 72 … Valve seat spring.

Claims (3)

An electric gas valve device installed in the gas supply path to the burner. An electromagnetic safety valve, a flow control valve, and an operation rod driven axially by an electric motor via an interlocking mechanism in the valve casing. A valve seat member that is movable in the axial direction is provided to partition the space inside the valve casing into a primary gas chamber on one axial direction and a gas chamber on the secondary side in the other axial direction. The electromagnetic safety valve has a safety valve valve seat facing the primary gas chamber provided in the valve seat member, a safety valve valve body facing the safety valve valve seat, and a safety valve valve. A valve spring that urges the body in the recovery direction to sit on the valve seat for the safety valve, a suction piece connected to the valve body for the safety valve via a valve shaft extending in the forward direction, and an electromagnet facing the suction piece. The flow control valve is adjustable so that it can be seated on the valve seat for the control valve facing the secondary gas chamber provided in the valve seat member and the valve seat for the control valve that moves in the axial direction integrally with the operation rod. It is equipped with a valve body for a valve and a bypass path for flowing gas from the primary gas chamber to the secondary gas chamber even when the valve for the control valve is seated on the valve seat for the control valve.
Inside the valve casing, a valve seat stopper that stops the movement of the valve seat member in the recovery direction at a predetermined recovery end position and a valve seat spring that urges the valve seat member in the recovery direction are provided and are electrically operated. By rotating the motor in the normal direction and moving the operation rod in the forward movement direction, the valve body for the control valve is seated on the valve seat for the control valve, and the valve seat member is pushed in the forward movement direction from the return end position. , The valve seat for the safety valve is brought into contact with the valve body for the safety valve, and the valve body for the safety valve is pushed against the urging force of the valve spring to the valve opening position where the attracted piece abuts on the electric magnet. The valve body for the safety valve is attracted and held at the valve opening position by energizing, and then the valve seat member is moved in the recovery direction by reversing the electric motor and moving the operation rod in the recovery direction, for the safety valve. The valve seat is separated from the safety valve valve body that is attracted and held at the valve opening position to open the electromagnetic safety valve, and the valve seat member reaches the recovery end position, and then the operation rod is further moved in the recovery direction. The movement of the valve body of the control valve is separated from the valve seat of the control valve so that the amount of gas supplied to the burner gradually increases.
Furthermore, when limiting the amount of gas supplied to the burner to the minimum amount specified by the bypass path during burner combustion, the electric motor is placed on the control valve seat of the valve seat member located at the return end position. In a device that rotates forward to a second rotation position that is deviated by a predetermined angle in the normal rotation direction from the first rotation position, which is the rotation position where the body sits.
A diaphragm facing the secondary gas chamber is provided, and a back pressure chamber separated from the secondary gas chamber is defined by the diaphragm, and a ventilation path connecting the secondary gas chamber and the back pressure chamber is provided. An electric gas valve provided, wherein the vent passage has a vent resistance such that the gas pressure in the back pressure chamber changes with a response delay after the gas pressure in the secondary gas chamber changes. Device. The diaphragm is arranged so as to face the end of the secondary gas chamber on the recovery direction side, the valve seat member is connected to the diaphragm, and the diaphragm is displaced axially together with the valve seat member. The electric gas valve device according to claim 1. The electric gas valve device according to claim 1 or 2, wherein the ventilation path is composed of an orifice hole formed in the diaphragm.

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