JP2009228785A - Motor safety valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein it is very difficult to stably hold a minimum combustion state, when a flow rate largely changes if the distance between a valve port and a valve element varies even a little, since the flow rate of gas is very small in the minimum combustion state, even if heating power can be actually squeezed to a certain degree, though the flow rate can be squeezed when the valve element is brought close to the valve port by reversing a motor, without stopping current-carrying to an electromagnet when closing a valve, since the valve is opened by attracting the valve element in a conventional motor safety valve. <P>SOLUTION: An orifice member 6 provided with an orifice part 61 is arranged on the tip of the valve element 5, and a second valve port 14 is arranged on the downstream side of the valve port 13. The orifice member 6 is seated on the second valve port 14 in a state before the valve element 5 closes the valve port 13, and gas is supplied to a gas passage 12 via the orifice part 61 of the orifice member 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor safety valve provided with throttle means that can throttle the flow rate corresponding to the minimum combustion state of a gas burner.

  A conventional motor safety valve includes a valve body that opens and closes a valve port serving as a gas passage, and this valve body is always biased by a spring in a valve closing direction. In addition, an electromagnet that advances and retreats by a motor is provided, the armature connected to the valve body is attracted by this electromagnet, and the valve opening is opened by moving the valve body against the urging force of the spring. For example, when the burner misfires, energization to the electromagnet is stopped, and the attractive force to the armature is extinguished. Then, the valve body immediately closes the valve port by the urging force of the spring, and the supply of gas to the burner is shut off (see, for example, Patent Document 1).

  Since such a motor safety valve is used to open and close the valve port, it is necessary to provide a control valve for adjusting the thermal power further downstream in order to change the thermal power of the burner. For example, when the heating power of the burner is switched between two levels of strength and weakness, an open / close type electromagnetic valve and a passage that bypasses the electromagnetic valve are provided downstream of the motor safety valve, and an orifice is provided in the bypass passage. In this case, if the solenoid valve is opened, the burner becomes a strong fire, and if the solenoid valve is closed, the gas is supplied only through the orifice, so the fire becomes weak.

In addition, when changing the thermal power continuously, a valve is attached to the tip of the rod that is advanced and retracted by the motor, and a thermal power control valve that adjusts the thermal power by continuously changing the distance between the valve port and the valve body is provided. Used (see, for example, Patent Document 2).
JP 2007-278321 A (FIG. 1) Japanese Patent Laying-Open No. 2003-232462 (FIG. 1)

  Since the motor safety valve adsorbs the valve body and opens it, the flow rate can be reduced if the motor is reversed and the valve body is brought closer to the valve opening without stopping energization of the electromagnet when closing the valve. . However, although it is possible to reduce the thermal power to some extent, it is very difficult to reduce the burner to the minimum combustion state. That is, since the gas flow rate is very small in the minimum combustion state, if the distance between the valve port and the valve body changes even a little, the flow rate changes greatly, and the minimum combustion state cannot be stably maintained.

  If the valve body has a tapered shape with a sharp tip as in Patent Document 2, the stability of the flow rate is increased, but the minimum combustion itself cannot be stably maintained.

  In view of the above problems, an object of the present invention is to provide a motor safety valve that can stably throttle the flow rate to a flow rate corresponding to the minimum combustion state.

  In order to solve the above-mentioned problems, a motor safety valve according to the present invention is provided in a gas passage for supplying gas to a burner, and closes a valve port connected to the gas passage with a valve body constantly energized in a valve closing direction. In addition, an electromagnet whose magnetic pole is advanced and retracted by a motor is provided, and the valve body is opened by adsorbing the valve body with this magnetic pole and opening it from the valve opening against the urging force. Thus, there is provided a throttle means capable of reducing the amount of gas flowing in the gas passage to a flow rate corresponding to the minimum combustion state of the gas burner.

  The flow rate corresponding to the minimum combustion state is not realized by the opening degree of the valve body, but the valve body itself is opened, and the flow rate is reduced by a separately provided throttle means.

  In addition, a throttle member provided with an orifice is provided at the tip of the valve body, a second valve port is provided downstream from the valve port, and the motor is driven to close the valve port by the valve body. Thus, the throttle member can be configured by seating the throttle member on the second valve port and supplying gas to the gas passage through the orifice portion of the throttle member.

  Further, a rod member that advances and retreats together with the magnetic pole of the electromagnet is provided, a throttle member having an orifice portion provided at the tip of the rod member, and a second valve port provided downstream from the valve port, thereby providing the throttle unit. Furthermore, when the valve body is provided in an annular shape surrounding the rod member and energization to the electromagnet is stopped while the valve body is open, the valve body is pushed by the urging force regardless of the position of the rod member and is closed. You may comprise so that it may valve.

  As is apparent from the above description, the present invention corresponds to the minimum combustion state with respect to the burner because the amount of gas flowing in the gas passage is restricted to the flow rate corresponding to the minimum combustion state of the gas burner by the throttle means instead of the valve body. A gas amount can be supplied stably.

  Referring to FIG. 1, reference numeral 1 denotes an internal structure of a motor safety valve according to the present invention. A motor 2 is attached to the upper part of the motor safety valve 1. The output shaft 21 of the motor 2 has a cylindrical shape and is internally threaded. The vertical shaft 3 is screwed into the inner screw. A core 4 made of a magnetic material is fixed to the vertical shaft 3. An excitation coil 41 is attached to the core 4, and when the excitation coil 41 is energized, the lower surface of the core 4 becomes a magnetic pole to attract the magnetic material.

  On the other hand, a cover 31 is connected to the vertical shaft 3, and the vertical shaft 3 is prevented from rotating by a blade portion 32 protruding from the cover 31. Therefore, when the output shaft 21 is rotated in both forward and reverse directions, the core 4 is raised and lowered according to the rotation of the output shaft 21.

  The gas flowing into the motor safety valve 1 from the gas inlet 11 is supplied to the burner through the valve port 13 and the outlet pipe 12. In the present embodiment, the second valve port 14 is further formed downstream of the valve port 13. The valve port 13 is closed by the rubber valve body 5, and the valve port 13 is opened when the valve body 5 is separated from the valve port 13. The valve body 5 is always urged downward by a spring 53. A valve shaft 51 extending upward is connected to the valve body 5, and an armature 52 is attached to the upper end of the valve shaft 51.

  A metal throttle member 6 was attached to the lower end of the valve body 5. The throttle member 6 is formed with an orifice portion 61 for flowing a flow rate corresponding to the minimum combustion state of the burner. When the throttle member 6 is seated on the second valve port 14, the gas is supplied to the burner only through the orifice portion 61, so that the burner is in a minimum combustion state.

  As described above, when the exciting coil 41 is energized, the core 4 becomes magnetized, so that the armature 52 is attracted to the core 4. In the state shown in FIG. 1, since the vertical shaft 3 is located at the rising end and the armature 52 is adsorbed to the core 4, both the valve body 5 and the throttle member 6 are separated from the valve port 13 and the second valve port 14. In position.

  In this state, the gas is supplied to the burner through the valve port 13 and the second valve port 14, so that the burning power of the burner is in a high fire state, that is, the maximum combustion state. The motor safety valve 1 immediately stops the gas supply to the burner when the burner misfires, etc., but the burning power of the burner can be switched to the minimum combustion state. In order to switch the burning power of the burner to the minimum combustion state, the motor 2 is operated and the vertical shaft 3 is lowered. Then, as shown in FIG. 2 (a), before the valve body 5 closes the valve port 13, the throttle member 6 is seated on the second valve port 14, and the amount of gas supplied to the burner is reduced as described above. Squeeze to reduce burner fire to minimum combustion. In order to return the burner's heating power to the maximum combustion state, it is sufficient to reverse the motor 2 and pull up the vertical shaft 3. However, in order to extinguish the fire, the motor 2 is further rotated to lower the vertical shaft 3. As shown in 2 (b), the valve body 5 may be closed by seating the valve body 5 on the valve opening 13. The valve body 5 may be closed by operating the motor 2 in this way, but the energization to the exciting coil 41 is stopped in the state shown in FIG. The valve body 5 may be moved to a position where the valve port 13 is closed by the biasing force of the spring 53.

  By the way, when the burner misfires in the fully opened state shown in FIG. 1, the energization to the exciting coil 41 is stopped. Then, as described above, the armature 52 moves away from the core 4 and descends due to the urging force of the spring 53, and as shown in FIG. 3, the valve body 5 closes the valve port 13 to be in a closed state, and the gas to the burner Is interrupted.

  However, when the valve is urgently closed from the fully opened state in this way, the metal throttle member 6 vigorously sits on the second valve port 14 before the valve body 5 closes the valve port 13, and a collision sound is generated. Arise. When it is desired not to generate such a collision sound, the configuration shown in FIG. 4 can be employed.

  With reference to FIG. 4, in the second embodiment, a nut portion 71 is provided that is threaded on the outer periphery of the output shaft 22 of the motor 2 and screwed into the output shaft 22. A shaft portion 7, which is a rod member, extends from the lower end of the nut portion 71, and the throttle member 6 is attached to the lower end of the shaft portion 7. On the other hand, a cylindrical holder 8 that surrounds the nut portion 71 and the shaft portion 7 is provided, and a ring-shaped valve body 72 is attached to the lower end of the holder 8 and a spring 73 that biases the valve body 72 downward is provided. It was. The nut portion 71 and the holder 8 are formed of a magnetic material, and the exciting coil 74 is provided so as to surround the upper end portion of the holder 8.

  When the exciting coil 74 is energized, the magnetic flux lines pass through the nut portion 71 and the holder 8, so that the lower end of the nut portion 71 becomes the magnetic pole 71a, and the holder 8 is attracted to the magnetic pole 71a. Although not shown, the nut portion 71 is prevented from rotating. In the state shown in FIG. 4, since the nut portion 71 is pulled up to the rising end, both the valve body 72 and the throttle member 6 are held at positions away from the valve port 13 and the second valve port 14. The gas is in a fully open state supplied through the valve port 13 and the valve port 14. In the configuration shown in FIG. 4, although not shown, a seal is provided between the shaft portion 7 and the holder 8, and gas does not escape downward through the inside of the holder 8.

  When the burner thermal power is reduced from the maximum combustion state to the minimum combustion state, the motor 2 is operated to lower the throttle member 6 in the same manner as shown in FIG. 1, and as shown in FIG. What is necessary is just to make it seat on the 2nd valve opening 14. FIG. In order to extinguish the burner, the nut portion 71 is further lowered, the valve body 72 is seated on the valve port 13 as shown in FIG. 5B, and the valve port 13 is closed. Alternatively, if the energization to the exciting coil 74 is stopped in the state shown in FIG. 5A, the attracting force acting between the nut portion 71 and the holder 8 disappears, and the valve body 72 is attached with the spring 73. It moves downward by the force to close the valve port 13.

  When the energization to the exciting coil 74 is stopped from the state shown in FIG. 4 due to misfire of the burner or the like, the valve body 72 closes the valve port 13 by the biasing force of the spring 73 as shown in FIG. 6 does not move from the position shown in FIG. That is, the throttle member 6 does not collide with the second valve port 14, and therefore no impact sound is generated.

  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 fully open state in 1st Embodiment (A) The figure which shows the state of the minimum opening degree in 1st Embodiment, (b) The figure which shows a fully-closed state similarly The figure which shows the fully closed state at the time of act | operating as a safety valve in 1st Embodiment The figure which shows the fully open state in 2nd Embodiment (A) The figure which shows the state of the minimum opening degree in 2nd Embodiment, (b) The figure which shows a fully-closed state similarly The figure which shows the fully closed state at the time of act | operating as a safety valve in 2nd Embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor safety valve 2 Motor 2 Output shaft 3 Vertical shaft 4 Core 5 Valve body 6 Throttle member 8 Holder 13 Valve port 14 Second valve port 21 Output shaft 22 Output shaft 41 Excitation coil 52 Armature 72 Valve body

Claims (3)

  An electromagnet, which is interposed in a gas passage for supplying gas to the burner and is continuously energized in the valve closing direction, closes the valve port connected to the gas passage and whose magnetic pole is advanced and retracted by a motor. In the motor safety valve that opens the valve port by adsorbing the valve element with the magnetic pole and separating it from the valve opening against the urging force, the valve body is open and the amount of gas flowing in the gas passage is reduced to the minimum combustion state of the gas burner. A motor safety valve provided with a throttle means capable of reducing the flow rate corresponding to the above.   A throttle member provided with an orifice is provided at the tip of the valve body, and a second valve port is provided downstream from the valve port, and the motor is driven to throttle the valve body before closing the valve port. 2. The motor safety valve according to claim 1, wherein the throttle means is configured by a member seated on the second valve port and supplying gas to the gas passage through the orifice portion of the throttle member.   The throttle means is configured by providing a rod member that moves forward and backward together with the magnetic pole of the electromagnet, providing a throttle member having an orifice at the tip of the rod member, and providing a second valve port downstream of the valve port. Further, when the valve body is provided in an annular shape surrounding the rod member and the energization of the electromagnet is stopped while the valve body is open, the valve body is pushed by the urging force regardless of the position of the rod member and is closed. The motor safety valve according to claim 1.

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