JP2014062662A - Gas flow rate controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which, in a conventional device, a rod disposed between a cam and an electromagnetic safety valve is not composed of an integral component but of one having a cylindrical shape and another having a piston shape, a spring is provided in a shrinking manner between the two, and the rod is shrunk by the spring being compressed in the state that the cam presses the rod most closely; however, when the rod is composed of the spring and two articles, the rod becomes long, so that a thermal power adjuster inconveniently increases in size.SOLUTION: A gas flow rate controller is provided with energizing means which holds a cam so that it reciprocally moves in the direction in which the cam presse a valve body most closely and energizes the cam in the direction in which it is most closely pressed, so that the cam retracts against an energizing force by the energizing means in the state that the cam presses the valve body most closely.

Description

  The present invention relates to a gas flow rate control device that forcibly opens an electromagnetic safety valve with a cam rotated by a motor when a gas burner is ignited.

  As a gas flow control device as described above, a cam that is rotated by a motor is provided on the upstream side of the thermal power control unit, and the rod is pushed by the cam, and the valve body of the electromagnetic safety valve is formed at the tip of the pushed rod. What is forcibly opened is known (for example, see Patent Document 1).

  In this case, when an ignition operation is performed, the motor operates to rotate the cam. The opening of the heating power adjustment unit is configured to be equivalent to a medium fire at the position where the cam most pushes the valve body. In this state, the igniter operates to ignite the gas burner.

  A movable iron piece is connected to the valve body. When the valve body is pressed, the movable iron piece is pressed against the magnetic pole of an electromagnet that is energized for a predetermined time. When it is confirmed that the gas burner is ignited, the energization of the electromagnet is continued and the movable iron piece is attracted and held by the magnetic pole. After this ignition, the motor further rotates to adjust the heating power of the gas burner by increasing or decreasing the opening degree of the heating power adjusting unit. During this heating power adjustment, the cam is already in a state of not pushing the rod, but the movable iron piece is adsorbed by the electromagnet, so that the valve body of the electromagnetic safety valve continues to be kept open. And if a fire extinguishing operation is performed, electricity supply to an electromagnet will be stopped and a valve body will move to a valve closing direction with the urging | biasing force of the spring which has urged | biased the valve closing direction.

Japanese Patent Laid-Open No. 2002-323218 (FIG. 1)

  In the above configuration, when the movable iron piece is attracted to the magnetic pole of the electromagnet, the movable iron piece needs to be firmly pressed against the magnetic pole in order to attract the movable iron piece with the minimum necessary current. Therefore, the rod positioned between the cam and the valve body must be pushed to a position where the valve body cannot move any further. However, if the movable iron piece already comes into contact with the magnetic pole before the cam reaches the state where the rod is pushed most, the rod cannot move further in the direction of pushing the valve body. A high load is applied to the motor, and the power consumption of the motor increases.

  For this reason, the rod is not composed of an integral part, and one of the two articles is made into a cylinder, the other is made into a piston, and a spring is contracted between the two so that the cam pushes the rod most. By compressing this spring, the two articles are relatively displaced and the length of the entire rod is reduced.

  However, if the rod is composed of the spring and the two articles in this way, the length of the rod itself becomes longer, and therefore the distance between the cam and the electromagnetic safety valve increases due to the interposition of the rod, resulting in the thermal power control device itself. There arises a problem that the size of is increased.

  In view of the above problems, an object of the present invention is to provide a gas flow rate control device that can shorten the distance between the cam and the electromagnetic safety valve as much as possible.

  In order to solve the above problems, a gas flow rate control apparatus according to the present invention has a cam that is rotated by a motor, and a movable body connected to the valve body by being pushed in a direction perpendicular to the rotation axis of the cam. An electromagnetic safety valve that holds the valve open state when the iron piece is pressed against the magnetic pole of the electromagnet and the movable iron piece is attracted by the magnetic force of the electromagnet is used to ignite the gas burner connected downstream. In the gas flow rate control device in which the movable iron piece is pressed against the magnetic pole of the electromagnet by pushing the magnet toward the electromagnet side, the cam is held so as to reciprocate in the direction in which the valve body is pushed most, and the cam is moved in the direction to which the cam is pushed most. An urging means is provided to urge the cam, and the cam is retracted against the urging force of the urging means in a state where the cam pushes the valve body most.

  In the conventional configuration, the rod disposed between the cam and the electromagnetic safety valve is composed of two articles, and the spring is disposed between the two. However, in the above configuration, the cam is moved. Even if it is interposed, the rod can be a single member, and as a result, the length of the rod can be made shorter than that of the conventional rod.

  If the valve shaft of the electromagnetic safety valve is protruded from the valve body toward the cam and the tip of the valve shaft is pushed directly by the cam, the rod itself can be omitted, and the cam and the electromagnetic safety valve The distance can be further shortened.

  As is clear from the above description, the present invention can make the distance between the cam and the electromagnetic safety valve shorter than the conventional one, so that the size of the thermal power control device itself can be reduced.

The figure which shows the structure of one embodiment of this invention II-II sectional view showing the structure of the cam The figure which shows the structure of 2nd Embodiment.

  Referring to FIG. 1, reference numeral 1 is a cross-sectional view showing an example of a main part of a thermal power control apparatus according to the present invention. Gas flows into the thermal power control apparatus 1 from the inlet 11. In the state shown in the drawing, this gas is first blocked by the valve body 32 of the electromagnetic safety valve 3 and does not flow downstream from the valve body 32.

  Reference numeral 2 denotes a stepping motor, and a main shaft 22 is connected to a rotating shaft 21 of the stepping motor 2. The main shaft 22 rotates together with the rotating shaft 21. A connecting shaft 23 is engaged with the upper end of the main shaft 22. The connecting shaft 23 rotates together with the main shaft 22. A rotating plate 24 that rotates together with the connecting shaft 23 is attached to the upper end of the connecting shaft 23. The rotating plate 24 is in close contact with the fixed plate 25 from below. When the through hole 24a formed in the rotating plate 24 and the through hole 25a formed in the fixed plate 25 match, the rotating plate 24 passes through the matching portion. The gas flows upward and is supplied to a gas burner (not shown). When the rotating plate 24 rotates, the area of the portion where the through hole 24a and the through hole 25a coincide with each other increases or decreases, so that the amount of gas supplied to the gas burner is adjusted.

  A cam plate 5 is attached to the connecting shaft 23. Referring also to FIG. 2, a rectangular engagement hole 51 is formed in the cam plate 5. On the other hand, the outer peripheral surface of the connecting shaft 23 has a rectangular shape. When the engaging hole 51 is engaged with the outer peripheral surface of the connecting shaft 23 as shown in the figure, the cam plate 5 rotates with the connecting shaft 23 and the connecting shaft The cam plate 5 can reciprocate with respect to 23. The reciprocating direction is a direction along a straight line passing through the rotation axis of the connecting shaft 23 and the top 5 a of the cam plate 5. A coil spring 52 is contracted between the connecting shaft 23 and the cam plate 5, and the cam plate 5 is always urged in a direction in which the top portion 5 a moves away from the rotation axis.

  Between the valve body 32 of the electromagnetic safety valve 3 and the cam plate 5, a reciprocating rod 4 is disposed. This rod 4 is composed of one member and can be reciprocated in the left-right direction in FIG. 1, but is attached in a state where it is not biased in any of the left-right direction. When the cam plate 5 rotates from the state shown in FIG. 2A to the state shown in FIG. 2B, the rod 4 is pushed in the direction toward the valve body 32 by the cam plate 5 and the valve body 32 is moved. Open the valve forcibly. The valve body 32 is attached to one end of the valve shaft 33, and a movable iron piece 34 is attached to the other end. When the valve body 32 is forcibly opened, the movable iron piece 34 approaches the magnetic pole 31 of the electromagnet built in the electromagnetic safety valve 3, and further moves to bring the movable iron piece 34 into close contact with the magnetic pole 31.

  In this state, as shown in FIG. 2 (b), the cam plate 5 retracts against the urging force of the coil spring 52, the top 5 a pushes the valve body 32 through the rod 4, and the movable iron piece 34 moves to the magnetic pole 31. A high load is not applied to the stepping motor 2 in the pressed state. In this state, the electromagnet of the electromagnetic safety valve 3 is energized for a predetermined time. When it is confirmed that the gas burner (not shown) is ignited, the energization is continued. Then, the movable iron piece 34 is attracted and held by the magnetic pole 31, and even if the cam plate 5 further rotates and the top portion 5a moves away from the tip of the rod 4, the valve body 32 remains open, and the gas is supplied to the gas burner. Will continue. Then, when the fire is extinguished, the energization of the electromagnet is stopped and the magnetic force adsorbing the movable iron piece 34 is extinguished, so that the valve body 32 is returned to the closed state by the urging force of the spring 35.

  In the above configuration, since the rod 4 can be constituted by a simple member by reciprocating the cam plate 5, the length of the rod 4 in the longitudinal direction can be made shorter than the conventional one. The distance between the plate 5 and the electromagnetic safety valve 3 is shortened, so that the overall size of the thermal power control device 1 can be made smaller than the conventional one.

  Further, in order to reduce the size of the thermal power control apparatus 1, the rod may be omitted as shown in FIG. In this configuration, the valve shaft 33 to which the valve body 32 is attached extends through the valve body 32 to the cam plate 5 side, and the tip 33a protruding from the valve body 32 to the cam plate 5 side is shown in FIG. The same function as the rod 4 shown was given. That is, the valve body 32 is forcibly opened by pushing the tip portion 33 a with the cam plate 5, and the movable iron piece 34 is pressed against the magnetic pole 31.

  Since the rod can be omitted by the configuration shown in FIG. 3, the thermal power control apparatus 1 can be further reduced in size as is apparent from comparison with FIG.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Thermal power adjusting device 2 Stepping motor 3 Electromagnetic safety valve 4 Rod 5 Cam plate 24 Rotating plate 25 Fixed plate 31 Magnetic pole 32 Valve body 33 Valve shaft 34 Movable iron piece 52 Coil spring

Claims (2)

  The movable iron piece connected to the valve body is pressed against the magnetic pole of the electromagnet by having the cam rotated by the motor and the valve body is pushed in a direction perpendicular to the rotation axis of the cam, and the movable iron piece is brought about by the magnetic force of the electromagnet. A gas that has an electromagnetic safety valve that keeps its valve open by being adsorbed and presses the valve element toward the electromagnet side by the cam and presses the movable iron piece against the magnetic pole of the electromagnet when igniting the gas burner connected downstream In the flow control device, the cam is held so as to reciprocate in the direction in which the cam most pushes the valve body, and biasing means for biasing the cam in the most pushing direction is provided. A gas flow rate control device characterized in that the cam is configured to move backward against the urging force of the urging means when pushed.   2. The gas flow rate control device according to claim 1, wherein the valve shaft of the electromagnetic safety valve is protruded from the valve body toward the cam, and the tip of the valve shaft is directly pushed by the cam.

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