JP6717694B2 - Gas valve device - Google Patents

Description

The present invention relates to a gas valve device including an electromagnetic safety valve arranged in a valve casing and an operating rod inserted in the valve casing.

In this type of gas valve device, the electromagnetic safety valve has a valve seat, a valve element that can be seated on the valve seat, and a valve element in the backward direction with one of the axial directions of the operating rod as the forward direction and the other as the backward direction. A valve spring that urges the valve seat to seat on the valve seat, an adsorption piece that is connected to the valve body via a valve shaft that extends in the forward direction, and an electromagnet that faces the adsorption piece. By moving the solenoid valve, the valve element of the electromagnetic safety valve is pushed against the biasing force of the valve spring to the valve opening position where the adsorption piece contacts the electromagnet.

Further, conventionally, as such a gas valve device, according to Patent Document 1, an electric motor and a motion conversion mechanism including a feed screw mechanism that converts rotational motion of an output shaft of the electric motor into axial motion of an operating rod are provided. At the same time, the valve seat member that is movable in the axial direction is housed in the valve casing, and the valve seat of the electromagnetic safety valve is formed on the end face of the valve seat member on the forward direction side. , The valve seat member is pushed by the operation rod to move in the forward direction so that the valve body of the electromagnetic safety valve is pushed to the open position via the valve seat member, and the return direction of the valve seat member is Is provided with valve seat stopper means for stopping movement of the electromagnetic safety valve at a predetermined position where the valve body of the electromagnetic safety valve can be seated on the valve seat, and valve seat urging means for urging the valve seat member in the backward direction. Has been.

In this type, the forward rotation of the output shaft of the electric motor moves the operating rod in the forward direction via the motion conversion mechanism, thereby pushing the valve body of the electromagnetic safety valve to the open position via the valve seat member. In this state, the electromagnet is energized to adsorb and hold the valve element at the valve opening position, and then the output shaft of the electric motor is reversed to move the operating rod in the backward direction. As a result, the valve seat member is moved in the returning direction to a predetermined position where it is stopped by the valve seat stopper means by following the operating rod by the urging force of the urging means, and the valve seat is attracted to the valve open position. And the electromagnetic safety valve is opened.

By the way, it is difficult to control the electric motor at the moment when the valve body of the electromagnetic safety valve reaches the valve opening position, that is, at the moment when the attraction piece contacts the electromagnet. Therefore, in the above-mentioned conventional example, an excessive force is applied to the contact portion between the attracting piece and the electromagnet by further normal rotation of the output shaft of the electric motor after the valve body of the electromagnetic safety valve reaches the valve opening position. , The suction piece may be scratched to cause suction failure.

Even if the movable valve seat member is omitted and the operation rod is directly brought into contact with the valve body of the electromagnetic safety valve to push the valve body to the valve open position, the operation rod is fed by an electric motor. When driving in the axial direction through the mechanism, the same problems as described above occur.

JP, 2013-68356, A

In view of the above points, the present invention is further forward rotation of the output shaft of the electric motor after the valve body of the electromagnetic safety valve reaches the valve opening position, and excessive force is applied to the contact portion between the attraction piece and the electromagnet. It is an object of the present invention to provide a gas valve device capable of preventing the addition.

In order to solve the above problems, the present invention comprises an electromagnetic safety valve arranged in a valve casing and an operating rod inserted in the valve casing, wherein one axial direction of the operating rod is the forward direction and the other is the backward direction. In terms of the direction, the electromagnetic safety valve is connected via a valve seat, a valve body, a valve spring that biases the valve body in the return direction to seat it on the valve seat, and a valve shaft that extends in the forward direction to the valve body. The solenoid valve is provided with a suction piece and an electromagnet that faces the suction piece, and the valve rod of the electromagnetic safety valve is resistant to the urging force of the valve spring until the valve is in the open position where the suction piece contacts the electromagnet. In the gas valve device for pushing the electric motor and the electric motor and the movement converting mechanism for converting the rotational movement of the output shaft of the electric motor into the axial movement of the operating rod, the movement converting mechanism is an electric motor. A cylindrical cam body concentric with the operating rod, and a pin fixed to the operating rod, the tubular cam body being concentric with the operating rod and being concentric with the output shaft of the operating rod. The cam body is constituted by a cam mechanism that allows the operation rod to move in the forward direction and the backward direction by the axial thrust acting from the cam groove via the pin when the cam body rotates normally and reversely. A cam stopper means that is axially movable with respect to the output shaft of the electric motor and that stops the forward movement of the cam body at a predetermined position; and a cam biasing means that biases the cam body in the forward movement direction. The cam body is provided with a cam from a predetermined position due to the axial reaction force acting from the pin through the cam groove by the forward rotation of the output shaft of the electric motor after the valve body of the electromagnetic safety valve reaches the valve opening position. It is characterized in that it moves in the backward direction against the urging force of the urging means.

According to the present invention, even if the output shaft of the electric motor further rotates in the normal direction after the valve body of the electromagnetic safety valve reaches the valve opening position, the forward movement acting on the operation rod by the movement of the cam body in the backward movement direction. The pressing force in the direction no longer increases. Therefore, an excessive force is not applied to the contact portion between the attracting piece and the electromagnet, and it is possible to prevent the attracting piece from being damaged due to scratches on the attracting piece.

In the present invention, similarly to the above-mentioned conventional example, the valve seat of the electromagnetic safety valve is formed on the end face on the forward direction side of the valve seat member housed in the valve casing so as to be movable in the axial direction, and By the movement in the moving direction, the valve seat member may be pushed by the operation rod to move in the forward movement direction, and the valve body of the electromagnetic safety valve may be pushed to the valve opening position via the valve seat member. In this case, a valve seat stopper means for stopping the movement of the valve seat member in the backward direction at a predetermined position where the valve body of the electromagnetic safety valve can be seated on the valve seat, and a valve seat for urging the valve seat member in the backward direction. It is necessary to provide a biasing means.

The cutting side view of the gas valve device of the embodiment of the present invention. Sectional drawing cut|disconnected by the II-II line of FIG. Operation|movement explanatory drawing of the gas valve apparatus of embodiment.

With reference to FIG. 1, a gas valve device according to an embodiment of the present invention includes a tubular valve casing 1 elongated in the front-rear direction (left-right direction in FIG. 1) and an electromagnetic safety valve 2 arranged at a rear portion of the valve casing 1. An opening/closing valve 3 arranged in series with the electromagnetic safety valve 2 in the front portion of the electromagnetic safety valve 2 in the valve casing 1, an operation rod 4 inserted in the valve casing 1 from the front and extending in the front-rear direction, and a valve casing. The electric motor 5 mounted on the front surface of the box 11 attached to the front end portion of No. 1 and the movement conversion for converting the rotational movement of the output shaft 51 of the electric motor 5 arranged in the box 11 into the axial movement of the operation rod 4. The mechanism 6 is provided. In the following description, one axial direction (rearward) of the operating rod 4 is referred to as a forward moving direction, and the other axial direction (frontward) is referred to as a backward moving direction.

The valve casing 1 is provided with a gas inlet 1a located upstream of the electromagnetic safety valve 2 and a gas outlet 1b located downstream of the on-off valve 3. When both the electromagnetic safety valve 2 and the on-off valve 3 are opened, gas flows from the gas inlet 1a to the gas outlet 1b, and the gas is supplied to the burner of a gas appliance such as a stove (not shown).

The electromagnetic safety valve 2 includes a valve seat 21 that faces the forward direction, a valve body 22 that faces the valve seat 21, a valve spring 23 that biases the valve body 22 in the backward direction to seat it on the valve seat 21, and a valve. An adsorption piece 24 connected to the body 22 via a valve shaft 22a extending in the forward direction and an electromagnet 25 facing the adsorption piece 24 are provided. Then, by energizing the electromagnet 25 while pushing the valve body 22 against the valve spring 23 up to the valve opening position (the position shown in FIG. 2) where the adsorption piece 24 contacts the electromagnet 25, the valve body 22 Is adsorbed and held at the valve open position. When the flame detecting element attached to the burner detects misfire of the burner, the energization of the electromagnet 25 is stopped, and the valve body 22 is returned by the valve spring 23 to the closed position where it is seated on the valve seat 21. The electromagnetic safety valve 2 is closed to prevent outflow of gas.

The valve seat 21 of the electromagnetic safety valve 2 is formed on an end face (rear end face) of the valve seat member 7, which is provided in the valve casing 1 and movable with respect to the valve casing 1, in the forward direction. Further, in the valve casing 1, a radial step 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 position where the valve body 22 of the electromagnetic safety valve 2 can be seated. And a valve seat urging means 72 composed of a coil spring for urging the valve seat member 7 in the backward direction to elastically hold the valve seat member 7 in the predetermined position.

The on-off valve 3 is seated on the valve seat 31 formed on the return-direction side end face (front end face) of the valve seat member 7, and is fixed to the forward-direction side end of the operation rod 4. And a valve body 32 that has been opened. The valve body 32 has a main valve body portion 321 which is seated on the valve seat 31 so as to close the valve hole 73 opened in the valve seat member 7 so as to be opened in both the valve seats 21 and 31 for the safety valve and the on-off valve. , A needle valve-shaped auxiliary valve body portion 322 inserted into the valve hole 73. A rubber valve seal 32a is attached to the end surface of the main valve body 321 facing the valve seat 31.

According to the above configuration, when the operation rod 4 is moved in the forward direction via the motion conversion mechanism 6 by the normal rotation of the output shaft 51 of the electric motor 5, the valve seat member is opened via the valve body 32 of the on-off valve 3. 7 is pushed in the forward direction, the valve seat 21 for the electromagnetic safety valve 2 formed on the valve seat member 7 contacts the valve body 22 of the electromagnetic safety valve 2, and the valve body 22 resists the urging force of the valve spring 23. And is pushed to the valve open position. In this state, the electromagnet 25 is energized, and the valve body 22 is adsorbed and held at the valve open position. Next, when the output shaft 51 of the electric motor 5 is rotated in the reverse direction, the operation rod 4 is moved in the backward direction via the motion conversion mechanism 6. At this time, the valve seat member 7 is at a predetermined position where it is stopped by the stopper means 71. Up to the operation rod 4 by the urging force of the urging means 72 to move in the backward direction, the valve seat 21 for the safety valve is separated from the valve body 22 adsorbed and held in the valve opening position, and the electromagnetic safety valve 2 is opened. Be spoken. After that, the operation rod 4 further moves in the backward direction with respect to the valve seat member 7 which is stopped at a predetermined position, and the main valve body portion 321 of the valve body 32 of the opening/closing valve 3 is separated from the valve seat 31 for opening/closing valve. Then, the on-off valve 3 is opened and gas is supplied to the burner. Furthermore, by adjusting the position of the operating rod 4 by the electric motor 5, the gas flow rate is adjusted by the sub valve body 322.

Here, even if a command to close the electromagnetic safety valve 2 is issued at the time of burner misfire, if an opening failure occurs in which the valve body 22 of the electromagnetic safety valve 2 remains held at the valve opening position, the operating rod 4 is moved forward. By moving the valve in the direction, the valve seat 21 abuts the valve body 22 in the valve open position, the electromagnetic safety valve 2 is closed, and the outflow of gas is prevented. Further, even if the operation rod 4 is locked at the forward end position corresponding to the valve opening position of the valve body 22 of the electromagnetic safety valve 2 due to a failure of the electric motor 5 or dust clogging, the electromagnetic safety valve 2 is closed. It is possible to prevent the release of gas. Therefore, fail-safe can be achieved when the electromagnetic safety valve 2 has an open failure or when the operation rod 4 is locked at the forward end position.

By the way, it is difficult to control the electric motor 5 at the moment when the valve body 22 of the electromagnetic safety valve 2 reaches the valve opening position, that is, at the moment when the attracting piece 24 contacts the electromagnet 25. Therefore, when the operation rod 4 is pushed in the forward direction via the motion conversion mechanism 6 by further forward rotation of the output shaft 51 of the electric motor 5 after the valve body 22 reaches the valve opening position, the suction piece 24 and Excessive force may be applied to the contact portion with the electromagnet 25, and the attraction piece 24 may be scratched, resulting in attraction failure.

Therefore, in this embodiment, the motion conversion mechanism 6 is configured as follows. That is, the motion converting mechanism 6 is connected to the output shaft 51 of the electric motor 5 so as to rotate integrally therewith, and has a cylindrical cam body 61 concentric with the operating rod 4, and a spiral shape formed on the cam body 61. Has a pin 62 fixed to the operation rod 4 that engages with the cam groove 61a of the operation rod 4, and the operation rod 4 is moved by the axial thrust acting from the cam groove 61a via the pin 62 in the normal rotation and the reverse rotation of the cam body 61. The cam mechanism is configured to move in the forward and backward directions.

Referring also to FIG. 2, a guide cylinder 65 extending in the backward direction from the end plate of the box 11 serving as a cam stopper means 63 described later is inserted in the cam body 61, and the operation rod 4 is inserted in the guide cylinder 65. The part on the backward direction side of is slidably inserted. Then, the axially long hole 65a formed in the guide cylinder 65 is slidably engaged with the radially outwardly extending pin 62 fixed to the backward movement side portion of the operation rod 4, so as to slide the operation rod. 65 is designed to be stopped. Further, the output shaft 51 is fixed with an annular connector 52 which is inserted into an end portion of the cam body 61 on the backward moving direction side. On the outer peripheral surface of the connector 52, there is provided a projection 52a slidably engaged with an axial split groove 61b formed in the peripheral wall of the cam body 61 at the end in the backward direction. The body 61 rotates integrally with the output shaft 51 via the connector 52.

Further, the cam body 61 is axially movable with respect to the output shaft 51, and is a cam stopper means 63 constituted by an end plate of the box 11 for stopping the movement of the cam body 61 in the forward movement direction at a predetermined position. And a cam biasing means 64 including a coil spring that biases the cam body 61 in the forward direction. Then, when the valve body 22 of the electromagnetic safety valve 2 reaches the valve opening position as shown in FIG. 3A, the output shaft 51 of the electric motor 5 is further rotated in the forward direction to act from the pin 62 through the cam groove 61a. The axial reaction force causes the cam body 61 to move in a backward direction from a predetermined position against the urging force of the cam urging means 64, as shown in FIG. 3B.

According to this, even if the output shaft 51 of the electric motor 5 further rotates in the forward direction after the valve body 22 of the electromagnetic safety valve 2 reaches the valve opening position, the cam body 61 moves in the backward movement direction, so that the operating rod 4 is moved. The pressing force in the forward direction that acts on the no longer increases. Therefore, an excessive force is not applied to the contact portion between the attraction piece 24 and the electromagnet 25, and it is possible to prevent the attraction failure from occurring due to scratches on the attraction piece 24.

Before the valve body 22 of the magnetic safety valve 2 reaches the valve opening position, the cam body 61 is prevented from moving in the backward movement direction due to the urging force of the valve spring 23 and the valve seat urging means 72. The urging force of the cam urging means 64 is set to be slightly larger than the combined force of the valve spring 23 and the valve seat urging means 72.

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, the on-off valve 3 is omitted, and a pin provided at the end of the operation rod 4 on the forward direction side is brought into contact with the end surface of the valve seat member 7 on the backward direction side. The member 7 may be pushed in the forward direction. Further, it is possible to omit the valve seat member 7 and bring the operating rod 4 into direct contact with the valve body 22 of the electromagnetic safety valve 2 to push the valve body 22 to the valve opening position.

DESCRIPTION OF SYMBOLS 1... Valve casing, 2... Electromagnetic safety valve, 21... Valve seat, 22... Valve body, 22a... Valve shaft, 23... Valve spring, 24... Adsorption piece, 25... Electromagnet, 4... Operation rod, 5... Electric motor, 51 ... output shaft, 6... motion conversion mechanism, 61... cam body, 61a... cam groove, 62... pin, 63... cam stopper means, 64... cam biasing means, 7... valve seat member, 71... valve seat stopper means, 72 ...Valve seat biasing means.

Claims (2)

An electromagnetic safety valve is provided in the valve casing and an operating rod inserted in the valve casing.One axial direction of the operating rod is the forward direction and the other is the returning direction.The electromagnetic safety valve has a valve seat and a valve. Body, a valve spring for urging the valve element in the backward direction to seat it on the valve seat, an adsorption piece connected to the valve element via a valve shaft extending in the forward direction, and an electromagnet facing the adsorption piece. A gas valve device that pushes the valve body of the electromagnetic safety valve against the biasing force of the valve spring to a valve opening position where the adsorption piece contacts the electromagnet by moving the operation rod in the forward direction, An electric motor and a motion conversion mechanism that converts the rotational motion of the output shaft of the electric motor into the axial motion of the operating rod,
The motion conversion mechanism is engaged with an output shaft of the electric motor so as to rotate integrally with the output shaft of the electric motor, and has a cylindrical cam body concentric with the operation rod and a spiral cam groove formed in the cam body. A cam mechanism that has a fixed pin on the operating rod, and that allows the operating rod to move in the forward and backward directions by the axial thrust acting from the cam groove via the pin in forward and reverse rotations of the cam body. Consists of
The cam body is axially movable with respect to the output shaft of the electric motor, and has cam stopper means for stopping the forward movement of the cam body at a predetermined position, and a cam for urging the cam body in the forward movement direction. The electromagnetic safety valve is provided with a biasing means, and after the valve body of the electromagnetic safety valve reaches the valve opening position, the cam body is moved to the predetermined position by the axial reaction force acting from the pin through the cam groove by the forward rotation of the output shaft of the electric motor. The gas valve device is characterized in that it moves in the backward direction against the biasing force of the cam biasing means. The valve seat of the electromagnetic safety valve is formed on an end face in the forward direction of a valve seat member housed in the valve casing so as to be movable in the axial direction, and the valve seat member is moved by the movement of the operating rod in the forward direction. It is pushed by the operating rod to move in the forward direction so that the valve element of the electromagnetic safety valve is pushed to the open position via the valve seat member, and the movement of the valve seat member in the backward direction is electromagnetically moved. 2. A valve seat stopper means for stopping the valve body of the safety valve at a predetermined position where it can be seated on the valve seat, and a valve seat urging means for urging the valve seat member in the backward movement direction. Gas valve device.

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