JP7120895B2 - Electric gas valve device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric gas valve device interposed in a gas supply passage to a burner.

Conventionally, as this type of electric gas valve device, there is known one in which an electromagnetic safety valve and an operating rod axially driven by an electric motor via an interlocking mechanism are provided in a valve casing (for example, See Patent Document 1). Here, the electromagnetic safety valve comprises an axially movable valve seat member that divides the space in the valve casing into a primary gas chamber on one side in the axial direction and a secondary side gas chamber on the other side in the axial direction, and a With the forward movement direction and the other axial direction as the return movement direction, a valve body facing the valve seat provided on the end surface of the valve seat member on the forward movement direction side so as to face the primary gas chamber, and the valve body are moved back. The valve includes a valve spring that biases the valve seat in a direction, an attracting piece that is connected to the valve body through a valve shaft that extends in the forward movement direction, and an electromagnet that faces the attracting piece. Further, the valve seat member is not connected to the operating rod, and moves in the forward direction by being pushed by the operating rod when the operating rod moves in the forward direction. Further, a valve seat stopper for stopping the movement of the valve seat member in the return movement direction at a predetermined return end position, and a valve seat spring for biasing the valve seat member in the return movement direction are provided in the valve casing. ing.

In the conventional example described above, the electric motor is rotated forward to move the operating rod in the forward direction, thereby pushing the valve seat member in the forward direction from the return end position and bringing the valve seat into contact with the valve body. In this state, the valve disc is pushed against the biasing force of the valve spring to the valve open position where the attracting piece abuts against the electromagnet, and the valve disc is attracted and held at the valve open position by energizing the electromagnet in this state. . After that, the electric motor is reversed to move the operating rod in the return direction, whereby the valve seat member is moved in the return direction following the operation rod by the biasing force of the valve seat spring, and the valve seat is moved to the valve open position. The electromagnetic safety valve is opened by separating it from the valve body adsorbed and held by the valve seat member so that gas flows from the primary side gas chamber to the secondary side gas chamber through the valve hole formed in the valve seat member.

Here, if the electromagnetic safety valve is left closed for a long period of time at low temperature, the valve body may stick to the valve seat. If such sticking occurs, in the above conventional example, even if the operating rod is moved in the backward movement direction after the valve body is sucked and held at the valve open position, the valve seat member will not move due to the biasing force of the valve seat spring. It does not move in the return direction, and the electromagnetic safety valve cannot be opened. The electromagnetic safety valve can be opened by increasing the biasing force of the valve seat spring so as to release the sticking between the valve body and the valve seat. However, in this case, in order to move the valve seat member in the forward direction against the biasing force of the valve seat spring from the return end position, it is necessary to increase the output of the electric motor, which increases power consumption. Therefore, it goes against the demand for power saving.

JP 2013-68356 A

In view of the above points, it is an object of the present invention to provide a simple and inexpensive electric gas valve device that can reliably open an electromagnetic safety valve even if sticking occurs between the valve body and the valve seat. is the subject.

In order to solve the above problems, the present invention provides an electric gas valve device interposed in a gas supply path to a burner, wherein an electromagnetic safety valve and an electric motor are provided in a valve casing to provide a shaft through an interlocking mechanism. The electromagnetic safety valve is axially movable and divides the space in the valve casing into a primary gas chamber on one side in the axial direction and a secondary gas chamber on the other side in the axial direction . The valve seat member faces the valve seat provided on the end surface of the valve seat member on the forward movement direction side so as to face the primary gas chamber, with one axial direction being the forward movement direction and the other axial direction being the return movement direction. A valve body, a valve spring that urges the valve body in the backward movement direction to seat it on the valve seat, an attracting piece connected to the valve body via a valve shaft extending in the forward movement direction, and an electromagnet that faces the attracting piece. , the valve seat member is connected to the operating rod so as to move axially together with the operating rod, and the valve seat member is moved by rotating the electric motor forward to move the operating rod in the forward direction. is moved in the forward direction, and with the valve seat in contact with the valve body, the valve body is pushed against the biasing force of the valve spring to the valve open position where the attracting piece contacts the electromagnet, and this state By energizing the electromagnet at , the valve body is attracted and held at the valve open position, and then the electric motor is reversed to move the operating rod in the return direction, thereby moving the valve seat member in the return direction. The electromagnetic safety valve is opened by separating the seat from the valve body attracted and held at the valve open position so that gas flows from the primary side gas chamber to the secondary side gas chamber through the valve hole formed in the valve seat member. It is characterized by

According to the present invention, the valve seat member is driven in the return direction by the force of the electric motor transmitted through the interlocking mechanism and the operating rod by the reverse rotation of the electric motor after the valve body is sucked and held at the valve open position. be done. Therefore, unlike the prior art, in which the valve seat member is moved in the return direction by the urging force of the valve seat spring, the valve seat member is returned by the force of the electric motor even if the valve disc and the valve seat stick. It moves in the dynamic direction, and the electromagnetic safety valve can be reliably opened. Furthermore, according to the present invention, a valve seat spring is not required, so that the structure can be simplified and the cost can be reduced.

In addition, by moving the valve seat member away from or approaching the valve body attracted and held at the valve open position to increase or decrease the distance between the valve body and the valve seat, the pressure from the primary gas chamber to the secondary gas chamber can be changed. can adjust the flow rate of the gas flowing to the In particular, a valve body is connected to a needle portion that is inserted into a valve hole and is tapered in the direction of return movement, and the distance between the valve body and the valve seat that is held at the valve open position by suction is determined by the return movement of the valve seat member. If the flow rate of the gas flowing from the primary side gas chamber to the secondary side gas chamber increases with the movement in the direction, the gas flow rate can be adjusted precisely and precisely.

1 is a cutaway side view of an electric gas valve device according to a first embodiment of the present invention; FIG. (a) and (b) are cutaway side views for explaining the operation of the electric gas valve device of the first embodiment. FIG. 5 is a cut side view of the electric gas valve device according to the second embodiment of the present invention; (a) and (b) are cutaway side views for explaining the operation of the electric gas valve device of the second embodiment.

Referring to FIG. 1, A is an electric gas valve device according to an embodiment of the present invention interposed in a gas supply line G to a burner B provided in a stove. This gas valve device A includes a valve casing 1 having a gas inlet 1a and a gas outlet 1b connected to a burner B. As shown in FIG. In the valve casing 1, an electromagnetic safety valve 2 and an operating rod 5 axially driven via an interlocking mechanism 4 by an electric motor 3 such as a stepping motor are provided.

The electric motor 3 is mounted on the outer end of a box 13 attached to the other axial end of the valve casing 1 so as to surround the interlocking mechanism 4 . The interlocking mechanism 4 is composed of a feed screw mechanism including a nut 41 connected to the output shaft 31 of the electric motor 3 and a male screw 42 screwed into the nut 41 and connected to the operating rod 5 .

The electromagnetic safety valve 2 partitions the space in the valve casing 1 into a primary gas chamber 11 on one side in the axial direction communicating with the gas inlet 1a and a secondary gas chamber 12 on the other side in the axial direction communicating with the gas outlet 1b. A valve seat member 6 which is freely movable in the axial direction is provided on the end face of the valve seat member 6 on the forward movement direction side so as to face the primary gas chamber 11, with one axial direction being the forward movement direction and the other axial direction being the return movement direction. a valve spring 23 that urges the valve body 22 in the reversing direction to seat it on the valve seat 21; and a valve shaft that extends in the reversing direction on the valve body 22 An attraction piece 24 connected via 22 a and an electromagnet 25 facing the attraction piece 24 are provided. Then, the electromagnet 25 is energized while the valve body 22 is pushed against the biasing force of the valve spring 23 to the valve open position (the position shown in FIG. 2(a)) where the attracting piece 24 contacts the electromagnet 25. Thus, the valve body 22 is held at the valve open position by adsorption. When a misfire is detected by a flame detection element (not shown) attached to the burner B or when extinguishing is performed, the electromagnet 25 is de-energized and the valve body 22 is moved to the valve seat 21 by the valve spring 23. The electromagnetic safety valve 2 is closed by returning to the seated valve closing position.

The valve seat member 6 is formed with a valve hole 61 that communicates the primary side gas chamber 11 and the secondary side gas chamber 12 with each other. Since the valve body 22 is seated on the valve seat 21 so as to block the valve hole 61 , gas does not flow from the primary side gas chamber 11 to the secondary side gas chamber 12 when the electromagnetic safety valve 2 is closed. An O-ring 62 is attached to the outer peripheral surface of the valve seat member 6 as a sealing member for sealing the gap between the outer peripheral surface of the valve seat member 6 and the inner peripheral surface of the valve casing 1 .

Here, in this embodiment, the valve seat member 6 is connected to the operating rod 5 so as to move axially together with the operating rod 5 . Although the valve seat member 6 is integrated with the operating rod 5 in this embodiment, it is also possible to connect the operating rod 5 with a separate valve seat member.

When the ignition operation is performed, first, the electric motor 3 is rotated forward to move the operating rod 5 in the forward direction, thereby moving the valve seat member 6 in the forward direction and moving the valve seat 21 to the valve body 22 . , the valve body 22 is pushed to the valve open position, and the electromagnet 25 is energized to attract and hold the valve body 22 at the valve open position. Next, the electric motor 3 is reversed and the igniter (not shown) is energized. At this time, the valve seat member 6 is driven in the backward movement direction by the force of the electric motor 3 transmitted through the interlocking mechanism 4 and the operating rod 5 as shown in FIG. 2(b). Therefore, unlike the above-described conventional example in which the valve seat member 6 is moved in the return direction by the urging force of the valve seat spring, the valve seat member 6 does not move even if the valve body 22 and the valve seat 21 stick to each other. The force of the electric motor 3 moves in the backward movement direction, and the electromagnetic safety valve 2 is reliably opened. By opening the electromagnetic safety valve 2, gas flows from the primary side gas chamber 11 to the secondary side gas chamber 12 through the valve hole 61 formed in the valve seat member 6, and the burner B can be reliably ignited. . Furthermore, the need for a valve seat spring is eliminated, so that the structure can be simplified and the cost can be reduced.

By increasing or decreasing the distance between the valve body 22 and the valve seat 21 by moving the valve seat member 6 away from or closer to the valve body 22 attracted and held at the valve open position, The gas flow rate flowing into the secondary gas chamber 12 can be adjusted. However, it is difficult to finely and accurately adjust the gas flow rate.

Therefore, a second embodiment shown in FIGS. 3 and 4, which can improve the accuracy of adjusting the gas flow rate, will be described. The basic structure of the second embodiment is not particularly different from that of the first embodiment, and members and parts similar to those of the first embodiment are denoted by the same reference numerals. The difference between the second embodiment and the first embodiment is that a needle portion 26 which is inserted into the valve hole 61 and is tapered in the return direction is connected to the valve body 22 .

In the second embodiment, as shown in FIG. 4(a), the electromagnet 25 is energized while the valve body 22 is pushed to the valve open position. By moving the valve seat member 6 in the return direction as shown in 4(b), gas flows from the primary side gas chamber 11 to the secondary side gas chamber 12 as the distance between the valve body 22 and the valve seat 21 increases. Flow increases. The needle portion 26 functions to finely and accurately adjust the gas flow rate.

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 above embodiment, the O-ring 62 is used as a sealing member for sealing the gap between the outer peripheral surface of the valve seat member 6 and the inner peripheral surface of the valve casing 1. A bellofram having an inner peripheral portion and an outer peripheral portion fixed to the inner peripheral surface of the valve casing 1 may be used. Further, in the above embodiment, the interlocking mechanism 4 is composed of a feed screw mechanism, but it is also possible to compose the interlocking mechanism 4 of a cam mechanism, a rack and pinion mechanism, or the like.

A... Electric gas valve device, B... Burner, G... Gas supply path, 1... Valve casing, 11... Primary side gas chamber, 12... Secondary side gas chamber, 2... Electromagnetic safety valve, 21... Valve seat, 22... Valve body 22a...Valve shaft 23...Valve spring 24...Adsorption piece 25...Electromagnet 26...Needle part 3...Electric motor 4...Interlocking mechanism 5...Operating rod 6...Valve seat member 61... valve hole.

Claims (2)

An electric gas valve device interposed in a gas supply path to a burner, wherein an electromagnetic safety valve and an operating rod axially driven by an electric motor via an interlocking mechanism are provided in a valve casing , The electromagnetic safety valve comprises an axially movable valve seat member that divides the space within the valve casing into a primary gas chamber on one side in the axial direction and a secondary side gas chamber on the other side in the axial direction; , with the other axial direction as the return movement direction, a valve body facing the valve seat provided on the forward movement direction side end face of the valve seat member so as to face the primary gas chamber, and the valve body attached in the return movement direction. A valve including a valve spring that is forced to be seated on a valve seat, an attracting piece connected to the valve body via a valve shaft extending in the forward movement direction, and an electromagnet facing the attracting piece,
the valve seat member is coupled to the operating rod so as to move axially together with the operating rod;
By rotating the electric motor forward and moving the operation rod in the forward direction, the valve seat member is moved in the forward direction. is pushed against the biasing force of the valve spring to the valve open position where the valve is in contact with the valve spring, and the electromagnet is energized in this state to attract and hold the valve disc at the valve open position. is moved in the return direction, the valve seat member is moved in the return direction, the valve seat is separated from the valve body sucked and held at the valve open position, the electromagnetic safety valve is opened, and the valve seat member moves An electric gas valve device characterized in that gas flows from a primary side gas chamber to a secondary side gas chamber through a formed valve hole. The valve body is connected to a needle portion that is tapered in the return direction and is inserted into the valve hole. 2. The electric gas valve device according to claim 1, wherein the flow rate of gas flowing from said primary side gas chamber to said secondary side gas chamber increases as it moves in the backward movement direction.

Images