JP4191744B2 - Control method of motor safety valve - Google Patents

Description

  The present invention includes a valve body that is connected to a movable iron piece and opens and closes a valve port through which gas flows out, and biasing means for biasing the valve body in a valve closing direction, against the biasing force of the biasing means The present invention relates to a control method for a motor safety valve having a movable electromagnet for attracting and holding a movable iron piece and a motor for moving the movable electromagnet back and forth in the opening / closing direction of a valve body.

  A conventional motor safety valve of this type has a movable electromagnet movable in the front-rear direction by a stepping motor or the like, and further has a movable iron piece movable in the front-rear direction at the tip of the movable electromagnet. A rubber valve body is attached to the tip of the movable iron piece, and a coil spring is attached between the movable iron piece and the movable electromagnet, and the valve body is biased in the forward direction of the movable electromagnet.

  On the other hand, a valve opening is formed in the forward direction of the movable electromagnet, and when the movable iron piece is not attracted to the movable electromagnet, the valve body is advanced together with the movable iron piece by the biasing force of the coil spring, and the valve opening is closed. (For example, refer to Patent Document 1).

When opening the valve port, the movable electromagnet is moved forward to bring the tip of the movable electromagnet into contact with the movable iron piece, and the motor is operated with the movable electromagnet excited to attract the movable iron piece. Retreat. Then, since the movable iron piece moves backward while being attracted to the movable electromagnet, the valve element attached to the tip of the movable iron piece also moves backward and the valve port is opened.
Japanese Patent Laying-Open No. 2003-232462 (FIG. 1)

  In the conventional motor safety valve described above, the valve body is pressed against the periphery of the valve opening by the biasing force of the coil spring when the valve opening is closed. The strength of the coil spring is set so that the valve opening is securely closed even when the movable electromagnet is retracted upward, so that the valve element is a valve, especially when the movable electromagnet approaches the movable iron piece and the coil spring is compressed. It will be strongly pressed against the periphery of the mouth. If this state continues for a long time, the valve element sticks to the periphery of the valve opening, and a large force is required to separate the valve element from the periphery of the valve opening. Therefore, the malfunction that the motor for retracting a movable electromagnet must be enlarged arises.

  In view of the above problems, an object of the present invention is to provide a motor safety valve control method that can reliably open the valve body by retracting the valve body without increasing the size of the motor.

In order to solve the above-described problems, a motor safety valve control method according to the present invention includes a rubber valve body that is connected to a movable iron piece and opens and closes a valve port through which gas flows out, and biases the valve body in a valve closing direction. In a method for controlling a motor safety valve, comprising: an urging unit that performs urging, a movable electromagnet that attracts and holds the movable iron piece against the urging force of the urging unit, and a motor that advances and retracts the movable electromagnet in the opening and closing direction of the valve body. When the valve body is opened after the valve opening has been closed for a predetermined time, the motor is operated to further advance the movable electromagnet from the state where the movable electromagnet is in contact with the movable iron piece. press, after releasing the adhesive between the periphery of the valve body and the valve port by isosamples pressed against the valve port is elastically deformed to the valve body, characterized by opened by retracting the movable electromagnet.

  Since the valve body is generally made of rubber, when the motor is operated to push the movable iron piece in the forward direction, the valve body is pressed against the valve port and elastically deformed. Then, the adhesive portion between the peripheral edge of the valve port and the valve body is peeled off. As described above, after the adhesion between the valve body and the periphery of the valve port is released, the motor is operated with the movable iron piece adsorbed, and the movable electromagnet is moved backward.

  According to this control method, the valve body is pressed against the periphery of the valve port. If there is a sharp part on the periphery of the valve opening, the valve body is damaged and the life of the valve body is shortened. In particular, when the inner peripheral edge of the valve port is processed at 90 degrees, the valve body is easily damaged. Therefore, it is desirable that the control method be applied to a motor safety valve in which at least the inner peripheral edge of the valve port is chamfered.

  As is apparent from the above description, according to the control method of the present invention, even if the valve body adheres to the periphery of the valve port, the adhesion between the valve body and the periphery of the valve port before the valve body is retracted. Therefore, even if the motor is not enlarged, the valve body can be moved backward to open the valve port.

  Referring to FIG. 1, reference numeral 1 is an example of a motor safety valve to which the control method of the present invention is applied. The motor safety valve housing 11 is provided with an inlet 12 through which gas flows and a valve port 13 through which gas flows out. A stepping motor 2 is attached to the upper portion of the housing 11. The stepping motor 2 rotates in proportion to the number of input pulses, and can be switched to rotate forward and backward.

  A male screw 21 is attached to the rotating shaft of the stepping motor 2. On the other hand, 3 is a movable electromagnet, which is fixed to a holder 31 that is screwed into the male screw 21. The holder 31 is inserted into the rotation stopper 14 so as to freely advance and retract. Further, the lower end of the rotation preventing portion 14 functions as a stopper upward of the holder 31. The movable electromagnet 3 is surrounded by a case 32 fixed to the holder 31.

  A movable iron piece 5 is arranged below the movable electromagnet 3. A rubber valve body 6 is attached to the lower end of the movable iron piece 5. A coil spring 4 is attached between the valve body 6 and the case 32. Accordingly, the valve body 6 is urged downward by the coil spring 4, and in the state shown in the figure, is pressed against the peripheral edge of the valve port 13 by the urging force of the coil spring 4. Therefore, the valve port 13 is closed.

  The inner peripheral edge 13a and the outer peripheral edge 13b at the peripheral edge of the valve port 13 were R processed. In the so-called chamfering process, a 90-degree corner is not formed, but the corner remains above and below the chamfer. On the other hand, when the R processing is performed as in the present embodiment, the surface changes gently and the corners are not formed.

  The state shown in FIG. 1 shows a state where the movable electromagnet 3 is located at the rising end position in the operating range of the movable electromagnet 3. Therefore, when the valve port 13 is opened, the stepping motor 2 is operated from the position shown in FIG. However, the stepping motor 2 causes a phenomenon called step-out during use, and the number of pulses input to the stepping motor 2 may deviate from the actual rotation amount. Therefore, it is necessary to compensate periodically.

  In the present embodiment, the holder 31 is further raised from the state shown in FIG. 1 to compensate. When the holder 31 is raised from the state shown in FIG. 1, the holder 31 abuts against the stopper 15 and can no longer be raised. If a pulse in the upward direction is continuously input to the stepping motor 2, the holder 31 cannot be raised, so that the stepping motor 2 is forcibly stepped out. Thereafter, the number of input pulses is reset, and the holder 31 is lowered to the position shown in FIG. 1 to compensate for the number of pulses.

  Next, in order to open the valve port 13, the movable electromagnet 3 is lowered to a position where it comes into contact with the movable iron piece 5 (see FIG. 2). However, the movable electromagnet 3 is not lowered at a stroke from the state shown in FIG. 1 to the state shown in FIG. 2, but is lowered in advance to a position where the movable electromagnet 3 is close to the movable iron piece 5 when not in use. There is a case where the time from when the (not shown) is pushed to when the valve port 13 is opened may be shortened.

  In this case, the coil spring 4 is in a compressed state while it is not in use, and the valve body 6 may stick to the periphery of the valve port 13 particularly when the coil spring 4 has passed for a long time. If the state in which the valve port 13 is closed is not continued for a predetermined time, the movable electromagnet 3 is excited from the state shown in FIG. 2 to attract the movable iron piece 5 and the stepping motor 2 is operated to move the movable iron piece 5. The valve body 6 may be lifted, but if the valve port 13 is closed for a predetermined time (for example, 72 hours) or longer, the movable electromagnet 3 is further moved forward from the state shown in FIG. The iron piece 5 was pushed down (see FIG. 3).

  Since the valve body 6 is made of rubber, when the movable iron piece 5 is pushed down, the valve body 6 is deformed so that the center is recessed as shown in FIG. Then, the lower surface of the valve body 6 warps on the outside with the inner periphery of the valve port 13 as a boundary, and is peeled off even if the outer periphery of the valve body 6 and the valve port 13 are adhered. In addition, since the inner peripheral edge 13a is R-processed as described above, there is no possibility that the lower surface of the valve body 6 is damaged.

  In this way, after the valve body 6 is elastically deformed, the movable electromagnet 3 is raised with the movable iron piece 5 adsorbed to the movable electromagnet 3 to open the valve port 13 (FIG. 4). Although the movable electromagnet 3 may be retracted all at once to the ascending end position shown in FIG. 4, it is divided into several steps so that the necessary minimum gas flow rate is opened to ensure the required gas flow rate. The movable electromagnet 3 may be retracted to the position shown in 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.

The figure which shows the valve closing state of the motor safety valve to which this invention is applied The figure which shows the state just before valve opening The figure which shows the state which made the valve body elastically deform The figure which shows the state which retracted the valve body to the fully open position

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor safety valve 2 Stepping motor 3 Movable electromagnet 4 Coil spring 5 Movable iron piece 6 Valve body

Claims (2)

A rubber valve body is connected to the movable iron piece and opens and closes a valve port through which gas flows out. The urging means urges the valve body in the valve closing direction, and is movable against the urging force of the urging means. In a motor safety valve control method having a movable electromagnet for attracting and holding an iron piece and a motor for moving the movable electromagnet back and forth in the opening and closing direction of the valve body, after the valve body has closed the valve opening for a predetermined time, the valve when to open the body, press the movable iron piece movable electromagnet actuates the motor to further advance the movable electromagnet from contact with the movable iron piece, by Rukoto is elastically deformed by pressing the valve body in the valve port A method for controlling a motor safety valve, comprising: opening a valve by retracting a movable electromagnet after releasing adhesion between a valve body and a peripheral edge of a valve port .   2. The motor safety valve control method according to claim 1, wherein the motor safety valve is applied to a motor safety valve in which at least an inner peripheral edge of the valve port is gently chamfered.

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