JP2009014132A - Solenoid safety valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a conventional fixed core makes defects occur that it enlarges to obtain mechanical strength not so as to deform even if the external force is applied since a magnetic surface is processed in an exposed state, and that the shape becomes complicated because it is necessary to provide a fixed surface for fixing to a processing machine and positioning, and for these reasons that a unit price of the fixed core is high. <P>SOLUTION: When injection molding of the bobbin 3 is performed, the fixed core 4 is cast into the bobbin 3 to expose only a magnetic surface 41. As a result, the bobbin prevents deformation owing to the external force so that the fixed core 4 can be miniaturized. The fixed surface is provided in the bobbin so that the shape can be simplified in the bobbin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic safety valve that includes an electromagnet having a fixed iron core therein and holds a valve open state by adsorbing a movable iron piece to a magnetic pole surface of the fixed iron core.

  A conventional electromagnetic safety valve is configured to form an electromagnet by winding a coil around a fixed iron core with both ends of a U-shaped fixed iron core as a magnetic pole surface, and to excite the magnetic pole surface of the fixed iron core to attract a movable iron piece (For example, refer to Patent Document 1).

As the energization amount to the coil increases, the attracting force to the magnetic pole surface increases. However, since power consumption increases, it is necessary to attract and hold the movable iron piece with the smallest energization amount. Therefore, both magnetic pole surfaces are polished and finished at the same time so as to form the same plane so that both attracting surfaces are in close contact with the movable iron piece without a gap.
Japanese Patent Laying-Open No. 2005-110385 (FIG. 7)

  Since the fixed iron core becomes a magnetic pole of the electromagnet, it is made of a soft magnetic material. In particular, when a metallic soft magnetic material is used, the fixed iron core is not so strong in mechanical strength. In the above conventional one, after finishing both magnetic pole faces of the fixed core, a coil is wound around the bare fixed iron core and housed in the holder of the electromagnetic safety valve. Due to the need to prevent deformation by external force, or to provide a fixed surface for finishing, the outer shape becomes complicated or large, resulting in a problem that processing costs and material costs increase.

  Even if both magnetic pole faces are finished at the same time when the fixed iron core is deformed, one of the two magnetic pole faces is inclined with respect to the other when it is finally assembled in the holder, and both magnetic pole faces are in close contact with the movable iron piece at the same time. become unable. For this reason, the attracting force with respect to the movable iron piece is weakened, and the movable iron piece cannot be attracted and held on the magnetic pole surface of the fixed iron core.

  Therefore, in view of the above problems, the present invention is an electromagnetic that can simplify and reduce the size of the fixed iron core while maintaining the performance that the fixed iron core is not deformed and can hold the movable iron piece with a small current. It is an object to provide a safety valve.

  In order to solve the above problems, an electromagnetic safety valve according to the present invention includes a fixed iron core, a bobbin attached to cover a part of the fixed iron core, and a coil wound around the bobbin and exciting the fixed iron core, In an electromagnetic safety valve that holds the valve body in an open state by attracting the movable iron piece connected to the valve body to the magnetic pole of the excited fixed iron core, the fixed iron core is formed in a substantially U shape and faces the movable iron piece A pair of magnetic pole surfaces are formed, and the bobbin is formed by resin molding, and the fixed iron core is cast into the bobbin so that both magnetic pole surfaces protrude from the bobbin during the molding. .

  In conventional electromagnetic safety valves, the fixed iron core is handled in a bare state when finishing both magnetic pole faces. However, in the present invention, when forming a bobbin, the fixed iron core is cast into the bobbin, and both are put in the cast state. Since the magnetic pole face is finished, the bobbin prevents deformation of the fixed core even if an external force is applied to the fixed core.

  In addition, since the fixed surface for finishing may be provided on the bobbin, the shape of the fixed iron core can be simplified and reduced in size. For example, the fixed iron core may be formed by bending a wire made of a magnetic material. .

In addition, the terminal rod with one end extending to the outside is held by the bobbin, the end of the coil is connected to the other end of the terminal rod, and the coil can be energized from the outside via the terminal rod. Also good.
If comprised in this way, since a fixed iron core, a coil, and a terminal can be integrated previously, productivity can be improved by simplifying a component structure and reducing an assembly man-hour.

  As is clear from the above description, in the present invention, since the fixed iron core is cast into the bobbin, the fixed iron core is difficult to be deformed when finishing both the magnetic pole faces, and therefore both the magnetic pole faces are in contact with the movable iron piece. It can adhere. For this reason, even with a small current, the movable iron piece can be attracted and held on the magnetic pole surface of the fixed iron core. Moreover, since the shape of the fixed core can be simplified and reduced in size, the manufacturing cost of the fixed core can be reduced.

  Referring to FIG. 1, reference numeral 1 denotes an electromagnetic safety valve according to the present invention. The electromagnetic safety valve 1 is provided with an electromagnet 2 housed in a holder 11. The electromagnet 2 includes a resin bobbin 3, a fixed iron core 4 held in the bobbin, and a coil 5 wound around the bobbin 3 to excite the fixed iron core 4. A pair of terminal rods 21 are attached to the bobbin 3, and both ends of the coil are connected to the terminal rods 21, and the coil 5 is energized via the terminal rods 21.

  When the coil 5 is energized, the fixed iron core 4 is excited, and both end surfaces of the fixed iron core 4 become magnetic pole surfaces 41. A movable iron piece 61 is disposed above these magnetic pole surfaces 41. The movable iron piece 61 is connected to the valve body 6, and the movable iron piece 61 together with the valve body 6 is biased upward by a spring 62.

  When the valve body 6 is pushed down against the urging force of the spring 62, the movable iron piece 61 comes into contact with the magnetic pole surface 41. When the coil 5 is energized in this state, the fixed iron core 4 is excited and the movable iron piece 61 is attracted to the magnetic pole surface 41 and held in that state. When the energization of the coil 5 is stopped, the magnetic force that has attracted and held the movable iron piece 61 disappears, so that the movable iron piece 61 is moved upward together with the valve body 6 by the urging force of the spring 62.

  Referring to FIG. 2, a fixed iron core 4 shown in FIG. 2A is obtained by cutting a wire-shaped soft magnetic material into a predetermined size and then bending it into a U shape. The fixed iron core 4 was cast into the bobbin 3 when the bobbin 3 was injection molded. Then, both the magnetic pole surfaces 41 of the exposed fixed iron core 4 are polished at the same time to adjust the surface roughness of the magnetic pole surface 41, and the both magnetic pole surfaces 41 form the same plane, as shown in FIG. A pair of terminal rods 21 was press-fitted into the bobbin 3, and the coil 5 was wound around the bobbin 3. After that, both ends of the coil 5 were connected to the terminal bars 21 at the upper ends.

  After the electromagnet 2 constructed integrally as described above is created, it is set in the holder 11 as shown in FIG. When the holder 11 is set in this manner, as shown in FIG. 4, the rubber packing 12 is attached to each of the terminal rods 21 projecting downward from the holder 11, and the packing 12 is held together with the holder 11 by pressing with the cover 13. It was made to adhere | attach on both of the terminal bars 21. FIG. The seal of the protruding portion of the terminal rod 21 is secured by the packing 12.

  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. For example, in the above embodiment, the bobbin is formed by resin injection molding, but may be formed by resin pressure molding.

The figure which shows the structure of one embodiment of this invention Diagram showing the configuration of an electromagnet The figure which shows the process of accommodating an electromagnet in a holder IV-IV sectional view showing the state where the electromagnet is housed in the holder

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic safety valve 2 Electromagnet 3 Bobbin 4 Fixed iron core 5 Coil 6 Valve body 11 Holder 21 Terminal rod 41 Magnetic pole surface 61 Movable iron piece

Claims (3)

  The fixed iron core includes a fixed iron core, a bobbin mounted to cover a part of the fixed iron core, and a coil wound around the bobbin to excite the fixed iron core, and a movable iron piece coupled to the valve body is excited. In the electromagnetic safety valve that is attracted to the magnetic pole of the magnet and holds the valve body in the open state, the fixed iron core is formed in a substantially U shape to form a pair of magnetic pole surfaces facing the movable iron piece, and the bobbin An electromagnetic safety valve formed by molding a resin and casting the fixed iron core into a bobbin so that both magnetic pole surfaces protrude from the bobbin.   2. The electromagnetic safety valve according to claim 1, wherein the fixed iron core is formed by bending a wire made of a magnetic material.   A terminal rod having one end extended to the outside is held by the bobbin, the end of the coil is connected to the other end of the terminal rod, and the coil can be energized from the outside via the terminal rod. The electromagnetic safety valve according to claim 1 or 2.

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