JP2020056554A - Electrically-driven gas valve device - Google Patents

Abstract

To prevent a capacity of a secondary-side gas chamber 12 from being enlarged and to prevent an accidental fire caused by gas pressure reduction when a valve seat member 7 is moved by rotating a motor 4 to a second rotation position in an electrically-driven gas valve device in which, in the case of throttling to minimum fire power, the motor 4 is rotated to the second rotation position exceeding a first rotation position where a valve body 32 is abutted to the valve seat member 7 held at a return end position where the motor is stopped by a valve seat stopper 71, by an energizing force of a valve seat spring 72, the electrically-driven gas valve device comprising a flow control valve 3 including a valve body 32 which is moved integrally with an operation rod 6 driven in an axial direction via an interlocking mechanism 5 by the motor 4, and an electromagnetic safety valve 2 which is pressed and opened by the valve body 32 via the valve seat member 7 that is movable in the axial direction.SOLUTION: In the case of throttling to minimum fire power, drive power of a motor 4 is limited in such a manner that a pressing force acting on a valve body 32 via an operation rod 6 becomes be equal to or less than an energizing force of a valve seat spring 72.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, as an electric gas valve device of this type, an electromagnetic safety valve, a flow control valve, an operation rod driven in an axial direction by an electric motor via an interlocking mechanism, and a space in the valve casing are provided in a valve casing. 2. Description of the Related Art There is known an axially movable valve seat member provided between an axial primary gas chamber and an axial secondary gas chamber (see, for example, Patent Document 1). Here, the electromagnetic safety valve is opposed to the safety valve valve seat facing the primary gas chamber provided in the valve seat member, with one axial direction being the forward movement direction and the other axial direction being the backward movement direction. Valve element, a valve spring for urging the valve element in the backward direction to seat on the valve seat for the safety valve, and a suction piece connected to the valve element for the safety valve via a valve shaft extending in the forward movement direction. And an electromagnet opposed to the adsorption piece, the flow control valve moves in the axial direction integrally with the control valve valve seat 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. In the valve casing, a valve seat stopper for stopping the movement of the valve seat member in the backward movement direction at a predetermined backward movement end position, and a valve seat spring for urging the valve seat member in the backward movement direction are provided. ing.

  In the above conventional example, the electric motor is rotated forward to move the operation rod in the forward movement direction, whereby the valve body for the control valve is seated on the valve seat for the control valve, and the valve seat member is moved from the backward end position. The safety valve seat 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 open position where the attraction piece contacts the electromagnet. By energizing the electromagnet in this state, the valve element for the safety valve is suction-held at the valve opening position. Thereafter, the electric motor is rotated in the reverse direction to move the operation rod in the backward movement direction, thereby moving the valve seat member in the backward movement direction, and separating the safety valve seat from the valve body for the safety valve which is sucked and held at the open position. Then, the electromagnetic safety valve is opened, and the valve body for the control valve is separated from the valve seat for the control valve by the further movement of the operation rod in the backward direction after the valve seat member reaches the return end position. The gas supply to the burner is gradually increased.

  Further, the flow control valve has a bypass passage for flowing gas 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. Here, when the gas supply amount to the burner is reduced to the minimum amount defined by the bypass during the burner combustion, the electric motor is moved to the valve seat for the control valve of the valve seat member at the backward end position. If the valve is stopped at the rotational position where the valve element is seated, the electric motor is driven before the valve element for the control valve is seated on the valve seat for the control valve 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 amount to the burner may not be reduced to the minimum amount specified by the bypass path. Therefore, conventionally, when reducing the gas supply amount to the burner during the burner combustion to the minimum amount specified by the bypass path, the electric motor is attached to the valve seat for the control valve of the valve seat member located at the backward end position. The normal rotation is performed to a second rotation position that is shifted 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, when the electric motor is rotated forward to the second rotation position, the valve body for the control valve is further moved in the forward movement direction after sitting on the valve seat for the control valve of the valve seat member located at the backward end position, The valve seat member is pushed by the adjusting valve body and moves in the forward movement direction. This movement increases the volume of the secondary gas chamber, temporarily lowers the gas pressure in the secondary gas chamber, and undershoots until the gas supply to the burner temporarily falls below the minimum amount. And may cause a fire.

JP 2018-13251 A

  SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an electric gas valve device capable of preventing a misfire when a gas supply amount to a burner is reduced to a 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, wherein an electromagnetic safety valve, a flow control valve, and an electric motor are interlocked in a valve casing. An operating rod driven in the axial direction via a mechanism, and a valve seat member movable in the axial direction that partitions a space in the valve casing into one primary gas chamber in the axial direction and the other secondary gas chamber in the axial direction. The electromagnetic safety valve has a valve seat for a safety valve facing a primary gas chamber provided on a valve seat member, and a valve seat for a safety valve. And a valve spring for urging the safety valve valve element in the backward direction to seat on the safety valve valve seat, and a valve shaft extending in the forward movement direction to the safety valve valve element. An adsorber and an electromagnet facing the adsorber are provided. A valve seat for a control valve facing the secondary gas chamber provided in the member, a valve body for a control valve that moves in the axial direction integrally with the operating rod, and can be seated on the valve seat for the control valve; A bypass passage for flowing gas from the primary gas chamber to the secondary gas chamber even when the valve element for a control valve is seated on the valve seat, and the movement of the valve seat member in the backward movement direction is predetermined in the valve casing. A valve seat stopper that stops at the return end position, and a valve seat spring that urges the valve seat member in the backward direction are provided. By rotating the electric motor forward to move the operation rod in the forward direction. , The valve body for the control valve is seated on the valve seat for the control valve, the valve seat member is pushed in the forward movement direction from the backward end position, and the valve seat for the safety valve is brought into contact with the valve body for the safety valve. The valve body is pushed against the urging force of the valve spring to the valve opening position where the attraction piece contacts the electromagnet. The valve element for the safety valve is sucked and held at the valve open position by applying electric power, and then the electric motor is rotated in the reverse direction to move the operating rod in the backward movement direction, thereby moving the valve seat member in the backward movement direction. The valve seat is separated from the valve body for the safety valve which is suction-held at the valve opening position, and the electromagnetic safety valve is opened, and further in the direction in which the operation rod is moved backward after the valve seat member reaches the return end position. The movement of the control valve separates the valve body for the control valve from the valve seat for the control valve so that the gas supply amount to the burner gradually increases, and furthermore, the gas supply amount to the burner is regulated by the bypass passage during burner combustion. When narrowing down to the minimum amount, the electric motor is rotated more forward than the first rotation position, which is the rotation position where the control valve valve element is seated on the control valve valve seat of the valve seat member located at the backward end position. For normal rotation to a second rotation position shifted by a predetermined angle When the electric motor is normally rotated to the second rotation position in order to reduce the gas supply amount to the burner from the rotation position where the control valve valve body is separated from the control valve valve seat to the minimum amount, A drive force limiting means for limiting the drive force of the electric motor so that the pressing force in the forward direction acting on the valve body for the control valve via the operation rod is equal to or less than the biasing force of the valve seat spring. And

  According to the present invention, by restricting the driving force of the electric motor when the gas supply amount to the burner is reduced to the minimum amount, the electric motor is moved to the valve seat for the control valve of the valve seat member at the backward end position. The valve seat member moves in the forward direction from the backward end position against the urging force of the valve seat spring even when the valve body is rotated forward beyond the first rotational position where the valve body is seated to the second rotational position. There is no. Accordingly, it is possible to prevent the gas supply amount from undershooting below the minimum amount due to the expansion of the volume of the secondary gas chamber, and to prevent misfire.

  Here, in the case where the electric motor is formed of a stepping motor, the drive frequency of the electric motor is increased, or the excitation method of the electric motor is switched from two-phase excitation to one-phase excitation or 1-2-phase excitation. The power decreases. Therefore, when the electric motor is a stepping motor, the driving force limiting means is configured to increase the driving frequency of the electric motor to a predetermined frequency or higher, or to change the excitation method of the electric motor from two-phase excitation to one-phase. What is necessary is just to comprise so that it may switch to excitation or 1-2 phase excitation.

1 is a cut-away side view of an electric gas valve device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of an interlocking mechanism provided in the electric gas valve device according to the embodiment. (A) (b) Cut-away side view of the principal part which shows operation | movement of the electric gas valve apparatus of embodiment. FIG. 4 is a flowchart showing the content of heat power adjustment control performed by the electric gas valve device of the embodiment.

  With reference to FIG. 1, A is an electric gas valve device according to an embodiment of the present invention provided on 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 a burner B. In the valve casing 1, an electromagnetic safety valve 2, a flow control valve 3, an operation rod 6 driven in an axial direction by an electric motor 4 composed of a stepping motor via an interlocking mechanism 5, and a space in the valve casing 1. An axially movable valve seat member 7 that separates into a primary gas chamber 11 in the axial direction communicating with the gas inlet 1a and a secondary gas chamber 12 in the other axial direction communicating with the gas outlet 1b. Is provided. The electric motor 4 is mounted on the outer end of a box 13 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 includes a safety valve seat 21 facing the primary gas chamber 11 provided in the valve seat member 7, with one axial direction being a forward movement direction and the other axial direction being a backward movement direction. , A valve spring 23 for urging the safety valve valve body 22 in the backward direction to seat on the safety valve valve seat 21, and a valve shaft extending in the forward movement direction of the safety valve valve body 22. An attraction piece 24 connected via the 22a and an electromagnet 25 facing the attraction piece 24 are provided. The safety valve body 22 is opened by energizing the safety valve body 22 in a state in which the suction piece 24 is pushed against the valve spring 23 to the valve opening position where the attraction piece 24 contacts the electromagnet 25. It is made to be sucked and held at the position. Further, when a misfire is detected by a flame detection element (not shown) attached to the burner B, or when a fire extinguishing operation is performed in which a point fire extinguishing button 9 described later is pushed to a fire extinguishing position, the power supply to the electromagnet 25 is stopped. The valve body 22 for the safety valve is returned to the valve closing position in which the valve body 22 for the safety valve is seated on the valve seat 21 for the safety valve by the valve spring 23, and the electromagnetic safety valve 2 is closed.

  The valve casing 1 includes a protrusion formed on the inner surface of the valve casing 1 for stopping the movement of the valve seat member 7 in the backward direction at a predetermined backward end position where the safety valve valve element 22 can be seated. A valve seat stopper 71 and a valve seat spring 72 that urges the valve seat member 7 in the backward movement direction and elastically holds the valve seat member 7 at the backward movement end position are provided. In addition, a bellofram 73 is provided to prevent gas from flowing between the primary gas chamber 11 and the secondary gas chamber 12 outside the valve seat member 7.

  The flow 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 axially integrally with the operation rod 6. Have. The valve body 32 for the control valve is inserted into the valve hole 31a from the returning direction into a closing valve portion 32a which can be seated on the valve seat 31 for the control valve so as to close the valve hole 31a opened in the valve seat 31 for the control valve. And a possible needle part 32b. Further, the flow control valve 3 includes a bypass passage 33 for flowing gas from the primary gas chamber 11 to the secondary gas chamber 12 even when the closing valve portion 32a is seated on the control valve valve seat 31. In this embodiment, the bypass passage 33 is formed in the valve body 32 for the control valve. However, the bypass passage 33 may be formed in the valve seat member 7. Further, in the present embodiment, the control valve valve body 32 is formed integrally with the operation rod 6, but the control valve valve body 32 may be attached to the operation rod 6 separately from the operation rod 6. Good.

  Referring also to FIG. 2, the interlocking mechanism 5 is engaged with a cylindrical cam body 54 that is driven by the electric motor 4 and is concentric with the operation rod 6, and a spiral cam groove 54 a formed in the cam body 54. And a pin 55 fixed to the operating rod 6, and the operating rod 6 is moved forward and backward by an axial thrust acting from the cam groove 54 a via the pin 55 when the cam body 54 rotates forward and backward. It is constituted by 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 a motor case, a rotation shaft 52 on the output side of the reduction gear train 51, and a connection for connecting the rotation shaft 52 and the cam body 54. A child 53 is provided. The connector 53 has a non-circular hole 53 a that fits into the rotary shaft 52 having a non-circular cross section, and rotates together with the rotary shaft 52. The connector 53 is provided with a protruding piece 53b that engages with a notch 54b formed at the end of the cam body 54 in the reciprocation direction to transmit the rotational force. A guide cylinder 56 extending from the valve casing 1 in the backward movement direction is inserted into the cam body 54. The guide cylinder 56 is formed with a long hole 56a that is long in the axial direction, and the pin 55 is slidably engaged with the long hole 56a in the axial direction. Further, a cam spring 58 is provided for urging and holding the end of the cam body 54 in the forward movement direction in contact with a cam stopper 57 formed by 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 a 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, which is displaced to an ignition position protruding from the surface of the operation panel section by pushing it in once from a fire extinguishing position substantially flush with the surface of the operation panel section and releasing the pushing. Can be rotated to adjust the heating power. Then, when performing an ignition operation for causing the point fire button 9 to protrude to the ignition position, the controller 8 rotates the electric motor 4 forward through the motor drive circuit 41. According to this, the operating rod 6 moves in the forward movement direction via the interlocking mechanism 5, and firstly, the closing valve portion 32 a of the control valve valve element 32 is at the return end position where it is stopped by the valve seat stopper 71. After sitting on the control valve valve seat 31 of the valve seat member 7, 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 (the state shown in FIG. 3A). In this state, the electromagnet 25 is energized to attract and hold the safety valve valve element 22 at the valve opening position. Thereafter, the electric motor 4 is rotated in the reverse direction to move the operation rod 6 in the backward movement direction, and energize an igniter (not shown). At this time, the valve seat member 7 moves in the backward movement direction following the operation rod 6 to the backward movement end position, and separates from the safety valve valve body 22 in which the safety valve seat 21 is sucked and held at the open position. Then, the electromagnetic safety valve 72 is opened, and gas supply to the burner B is started. Thereafter, the control valve valve body 32 is further moved in the backward movement direction with respect to the valve seat member 7 which is stopped at the return end position, and the closing valve portion 32a is separated from the control valve valve seat 31 and the burner B is moved to the burner B. The gas supply is gradually increased and the burner B is ignited. After the burner ignition, the control valve valve body 32 moves in the forward movement direction, and the control valve valve body 32 (actually, the closing valve) is inserted into the control valve seat 31 of the valve seat member 7 located at the backward end position. When the portion 32a) is seated (the state shown in FIG. 3B), gas flows only through the bypass 33, and the amount of gas supplied to the burner B is minimized.

  However, if the electric motor 4 is stopped at the rotation position where the control valve valve body 32 is seated on the control valve valve seat 31 of the valve seat member 7 located at the return end position, Due to dimensional tolerances, position tolerances of the valve seat stopper 71, and the like, the electric motor 4 is stopped 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 by the bypass passage 33. It may not be possible to narrow down to the minimum amount specified in. Therefore, when the heating power indicated by the point fire extinguishing button 9 is changed to the minimum heating power during the burner combustion, and the gas supply amount to the burner B is reduced to the minimum amount specified by the bypass passage 33, the electric motor 4 is turned on. The second rotation which is shifted 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 valve seat 31 of the valve seat member 7 located at the return end position. It rotates forward to the position.

  However, the forward rotation of the electric motor 4 from the first rotation position to the second rotation position causes the valve seat member 7 to be pushed by the control valve valve body 32 and move in the forward movement direction from the backward end position. The volume of the secondary gas chamber 12 increases, the gas pressure in the secondary gas chamber 12 temporarily decreases, and the gas supply amount to the burner B temporarily drops below the minimum amount. Shooting may cause a misfire.

  Therefore, in the present embodiment, the electric motor 4 is set to the second position in order to reduce the amount of gas supplied to the burner B from the rotation position where the control valve valve body 32 is separated from the control valve valve seat 31 to the minimum amount. When the electric motor 4 is rotated forward to the rotation position, the pressing force in the forward direction acting on the control valve valve body 32 via the operating rod 6 in the forward direction becomes less than the urging force of the valve seat spring 72. A driving force limiting means for limiting the driving force is provided.

  More specifically, when the electric motor 4 is configured by a stepping motor as in the present embodiment, when the frequency (drive frequency) of the drive pulse output from the motor drive circuit 41 increases, the driving force of the electric motor 4 is reduced. Decrease. Therefore, the frequency switching unit 42 is incorporated in the motor drive circuit 41 so that the driving frequency is adjusted such that the pressing force in the forward direction acting on the control valve valve body 32 via the operating rod 6 exceeds the urging force of the valve seat spring 72. The first set frequency (for example, 300 Hz) and the second set frequency (for example, 600 Hz) which is equal to or higher than a predetermined frequency at which the pressing force is equal to or lower than the urging force of the valve seat spring 72 can be switched by a command from the controller 8. ing. Then, during the burner combustion, the heating power adjustment control shown in FIG. 4 is performed.

  In this heating power adjustment control, first, in STEP1, it is determined whether or not the turning operation of the point fire extinguishing button 9 has been performed, that is, whether or not the indicated heating power has been changed. It is determined whether or not has been changed to the minimum heating power. When the designated heating power is changed to a heating power other than the minimum heating power, the process proceeds to STEP 3 and the electric motor 4 is driven with the driving frequency set to the first set frequency. Then, when it is determined in STEP 4 that the rotation position of the electric motor 4 has reached the rotation position corresponding to the indicated heating power, the process proceeds to STEP 7 and stops the electric motor 4. Even when the ignition operation is performed, the electric motor 4 is driven with the driving frequency set to the first set frequency so that the valve seat member 7 can be pushed in the forward movement direction from the backward end position.

  On the other hand, if the indicated heating power has been changed to the minimum heating power, the process proceeds from STEP 2 to STEP 5 to drive the electric motor 4 with the driving frequency set to the second set frequency. When it is determined in STEP 6 that the rotation position of the electric motor 4 has reached the second rotation position, the process proceeds to STEP 7 and stops the electric motor 4. Note that the rotational position of the electric motor 4 is calculated based on the number of output drive pulses.

  According to the present embodiment, when the heating power of the burner B is reduced to the minimum heating power, the driving force of the electric motor 4 is determined by the pressing force in the forward direction acting on the control valve valve body 32 via the operation rod 6. It is limited so as to be equal to or less than the urging force of the seat spring 72. Therefore, the electric motor 4 is rotated forward beyond the first rotation position where the control valve valve body 32 is seated on the control valve valve seat 31 of the valve seat member 7 located at the backward end position to the second rotation position. However, the valve seat member 7 does not move in the forward movement direction from the backward end position against the urging force of the valve seat spring 72. Therefore, it is possible to suppress the gas supply amount from undershooting to an amount smaller than the minimum amount due to the expansion of the volume of the secondary gas chamber 12, and to prevent misfire.

  In the above embodiment, the driving force limiting unit increases the driving frequency of the electric motor 4 to the second set frequency equal to or higher than the predetermined frequency when the controller 8 and the frequency switching unit 42 reduce the heating power to the minimum heating power. Although configured, the driving force limiting means may be configured to switch the excitation method of the electric motor 4 from two-phase excitation to one-phase excitation or 1-2-phase excitation. That is, in the case where the electric motor 4 is configured by a stepping motor, when the excitation method of the electric motor 4 is switched from two-phase excitation to one-phase excitation or 1-2-phase excitation, the motor driving force decreases. When the voltage level of the drive pulse is two-phase excitation, the pressing force in the forward direction acting on the control valve valve element 32 via the operating rod 6 exceeds the urging force of the valve seat spring 72, and the one-phase excitation is performed. Alternatively, in the 1-2-phase excitation, the pressing force is set to be equal to or less than the urging force of the valve seat spring 72. According to this, when the heating power of the burner B is reduced to the minimum heating power, by switching from two-phase excitation to one-phase excitation or 1-2-phase excitation, even if the electric motor 4 is rotated forward to the second rotation position, Thus, the valve seat member 7 does not move from the backward end position to the forward movement direction, and the same effect as the above embodiment can be obtained. In this case, the motor drive circuit 41 incorporates, instead of the frequency switching unit 42 of the above-described embodiment, an excitation mode switching unit that switches the excitation mode between two-phase excitation, one-phase excitation, and 1-2-phase excitation.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited thereto. For example, the electric motor 4 can be configured by a motor other than the stepping motor. Further, the driving force limiting means reduces the motor current so that the pressing force acting on the control valve valve body 32 via the operation rod 6 in the forward movement direction is equal to or less than the urging force of the valve seat spring 72. You can also. Further, in the above-described embodiment, the interlocking mechanism 5 is configured by the cam mechanism having the cylindrical cam body 54. However, the interlocking mechanism may be configured by a feed screw mechanism. Further, the electric motor may be disposed so as to be orthogonal to the valve casing in the axial direction, and the interlocking mechanism may be configured by a rack and pinion mechanism including a rack connected to the operation rod and a motor-driven pinion that meshes with the rack. It is possible.

  Further, in the above-described embodiment, the gas supply amount to the burner B is adjusted according to the fire power indicated by the fire extinguishing button 9, but the gas supply to the burner B is controlled according to the temperature detected by the pan bottom temperature sensor attached to the burner B. Even when the supply amount is adjusted, the same thermal power adjustment control as described above can be performed. Further, the present invention can be similarly applied to an electric gas valve device provided in a gas supply path to a burner other than the stove burner.

  A: Electric gas valve device, B: Burner, G: Gas supply path, 1: Valve casing, 11: Primary gas chamber, 12: Secondary gas chamber, 2: Electromagnetic safety valve, 21: Valve seat for safety valve, Reference numeral 22: safety valve valve element, 22a: valve shaft, 23: valve spring, 24: suction piece, 25: electromagnet, 3: flow control valve, 31: control valve valve seat, 32: control valve valve element, 33: Bypass path, 4 ... Electric motor, 42 ... Frequency switching section (driving force limiting means), 5 ... Interlocking mechanism, 6 ... Operation rod, 7 ... Valve seat member, 71 ... Valve stopper, 72 ... Valve spring, 8 ... Controller (driving force limiting means).

Claims (3)

An electric gas valve device interposed in a gas supply path to a burner, comprising: an electromagnetic safety valve, a flow control valve, and an operation rod axially driven by an electric motor via an interlocking mechanism in a valve casing. And an axially movable valve seat member that divides a space in the valve casing into one primary gas chamber in the axial direction and the other secondary gas chamber in the axial direction. The electromagnetic safety valve includes a valve seat for a safety valve facing a primary gas chamber provided in a valve seat member, a valve element for a safety valve facing the valve seat for a safety valve, and a valve for a safety valve. A valve spring that urges the body in the backward direction to seat on the valve seat for the safety valve, a suction piece connected to the safety valve valve body via a valve shaft extending in the forward movement direction, and an electromagnet facing the suction piece. The flow control valve faces a secondary gas chamber provided in the valve seat member. A control valve valve seat, a control valve valve body that moves in the axial direction integrally with the operation rod, and can be seated on the control valve valve seat, and even when the control valve valve body is seated on the control valve valve seat. A bypass for flowing gas from the primary gas chamber to the secondary gas chamber,
In the valve casing, a valve seat stopper that stops movement of the valve seat member in the backward direction at a predetermined backward end position, and a valve seat spring that biases the valve seat member in the backward direction are provided. By rotating the motor forward and moving the operation rod in the forward 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 direction from the backward end position. Then, 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 until the open position where the attraction piece contacts the electromagnet. By energizing, the valve element for the safety valve is sucked and held at the open position, and then the electric motor is rotated in reverse to move the operating rod in the backward direction, thereby moving the valve seat member in the backward direction, and The valve seat is separated from the valve element for the safety valve that is suction-held at the open position, and the electromagnetic safety valve is When the valve is opened and the operating rod further moves in the reversing direction after the valve seat member reaches the reversing end position, the control valve valve body separates from the control valve valve seat and gas is supplied to the burner. So that the volume gradually increases,
Further, when the gas supply amount to the burner is reduced to the minimum amount specified by the bypass during the burner combustion, the electric motor is connected to the valve seat for the control valve of the valve seat member located at the backward end position. In a normal rotation to a second rotation position which is shifted by a predetermined angle in the normal rotation direction from the first rotation position which is the rotation position where the body is seated,
When the electric motor is rotated forward to a second rotation position in order to reduce the gas supply amount to the burner from a rotation position where the control valve valve body is separated from the control valve valve seat to a minimum amount, the electric motor A driving force restricting means for restricting the driving force of the valve member in the forward direction acting on the valve body for the control valve via the operating rod to be equal to or less than the urging force of the valve seat spring. Electric gas valve device.   2. The electric gas valve device according to claim 1, wherein the electric motor is a stepping motor, wherein the driving force limiting means is configured to increase a driving frequency of the electric motor to a predetermined frequency or more. An electrically operated gas valve device.   2. The electric gas valve device according to claim 1, wherein the electric motor is a stepping motor, wherein the driving force limiting means changes the excitation mode of the electric motor from two-phase excitation to one-phase excitation or 1-2-phase excitation. An electric gas valve device configured to switch to excitation.

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