JP4563088B2 - Electromagnetic actuator - Google Patents

Description

  The present invention relates to an electromagnetic actuator that is required to be waterproof and water-resistant, for example, an electric expansion valve for a refrigeration / refrigeration cycle, an electric valve for switching a flow path, and the like, and particularly reduces manufacturing man-hours and jig costs. Regarding technology.

  Among electromagnetic actuators used in motor-operated valves, stepping motors, etc. (see, for example, Patent Document 1), those used in environments where high humidity and condensation are required and used for applications that require waterproofness and water resistance Is conventionally produced by the method shown in FIG.

  As shown in the figure, an assembly comprising an annular stator yoke 11 in which a plurality of pole teeth 12 are erected in the axial direction along an inner peripheral portion, and a cylindrical bobbin 21 around which an exciting coil 31 is wound. (2 sets in the figure) are housed in a cylindrical frame yoke 41, and in this state, resin is cast and sealed between the frame yoke 41 and the exciting coil 31 to produce an electromagnetic actuator. .

  In the structure in which the bobbin 21 and the stator yoke 41 are stacked and assembled as shown in the same figure, the casting resin is filled between the pole teeth 12 of the stator yoke 41 where the press fracture surface is exposed. At this time, it is necessary to insert the core mold 92 into the central through hole to prevent the casting resin from flowing out.

  Even when an assembly of the bobbin 21 and the stator yoke 41 is plated with a fractured surface of the press or integrally formed with the bobbin 21 and the stator yoke 41, the assembly between the case main body and the like serving as an outer frame is used. Since there is a gap, it is necessary to hold down this with a holding jig 93 or the like to prevent the resin from flowing out during casting.

  As the casting resin, a thermosetting resin is mainly used, but it takes several tens of minutes to several hours to cure after pouring. During that time, the resin is formed using the core die 92 and the holding jig 93. It is necessary to prevent spillage.

For this reason, a large number of core molds 92 and holding jigs 93 are required, and time for attachment and removal is required. Further, the core mold 92 has a problem in durability because a relatively soft fluorine-based material is used to improve the releasability.
JP 2000-262024 A

  The present invention has been made in order to solve the above-described problems in the prior art, and the resin is used without using a member for preventing the casting resin from flowing out, such as a core mold and a holding jig. An object of the present invention is to provide an electromagnetic actuator that can be sealed.

In the electromagnetic actuator of the present invention, a pair of annular stator yokes having a plurality of pole teeth erected along the inner periphery is fixed to the bobbin so that these pole teeth face each other, and the outer periphery of the bobbin An exciting coil is wound on the magnetic coil, and a magnetic circuit is formed by fitting the annular stator yoke to a cylindrical frame yoke,
An assembly composed of the frame yoke, the stator yoke and the bobbin is housed in the case main body, and casting resin is injected into a space formed by the inner peripheral side of the case main body and the outer peripheral side of the bobbin. An electromagnetic actuator in which the space is sealed with resin,
On one end surface of the bobbin, a casting resin blocking rib formed in a circumferential shape so as to surround an opening of a central through hole in which the pole teeth are disposed,
A circumferential groove is formed on the bottom surface of the case body, and includes a fitting groove fitted to the casting resin blocking rib,
By injecting the casting resin into the space formed by the inner peripheral side of the case body and the outer peripheral side of the bobbin by fitting the casting resin blocking rib into the fitting groove, The bottom surface of the case body is liquid-tightly blocked from the outside.

  In the above invention, the bottom surface of the case body is formed by fitting the casting resin blocking rib formed circumferentially on one end surface of the bobbin into the fitting groove formed circumferentially on the bottom surface portion of the case body. The part side is sealed without a gap. By pouring the casting resin from the upper side of the case main body in this state, the casting resin is filled in a predetermined space, and the casting resin does not flow out to the outside without using the core mold and the holding jig. .

  Therefore, there is no need to use a separate member such as a core mold and a holding jig when casting, and it is not necessary to attach, remove, and maintain the core mold and the holding jig, thereby reducing the number of manufacturing steps. The cost of the electromagnetic actuator can be reduced.

Further, since there is no resin outflow from the gap caused by core-type wear or the like, the defect rate can be reduced.
The bobbin is formed by inserting a stator yoke made of iron-based metal into a mold and integrally molding the stator yoke by injection molding, and also forming the above-mentioned casting resin blocking rib at the time of injection molding. The space into which the casting resin between the case main body and the molded body composed of the bobbin and the stator yoke housed therein is injected is liquid-tightly sealed except for the upper part, and the injected casting resin Does not flow out.

  The electromagnetic actuator of the present invention is formed on the end surface of the bobbin opposite to the end surface on which the casting resin blocking rib is formed so as to surround the opening of the central through hole, When the casting resin is poured into the space formed by the inner peripheral side and the outer peripheral side of the bobbin, an outflow prevention rib is provided to prevent the casting resin from flowing out to the outside. .

  In the above invention, when the casting resin is injected into the space formed by the inner peripheral side of the case body and the outer peripheral side of the bobbin, the liquid level of the casting resin protrudes from the upper end surface of the bobbin. The casting resin can be poured up to a height defined by the outflow prevention rib.

  Therefore, even if the casting resin is filled up to the upper side of the metal members such as the coil, the stator yoke and the frame yoke and these are resin-sealed, the casting resin does not flow out to the central through hole side.

  The electromagnetic actuator of the present invention has a casting resin blocking rib formed on one end surface of the bobbin. Therefore, without using a member for preventing the casting resin from flowing out, such as a core mold and a holding jig. Resin sealing is possible.

  In addition, since the rib for preventing outflow is formed on the other end face of the bobbin, even if the casting resin is filled to the upper side of metal members such as coils, stator yokes and frame yokes, and these are resin-sealed, the center penetration The casting resin does not flow out to the hole side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a sectional view showing an embodiment of an electromagnetic actuator of the present invention, FIG. 2 is a perspective view of a frame yoke, FIG. 3 is a perspective view of a molded body of a bobbin and a stator yoke, and FIG. 4 is a cover body. FIG. 5 is a cross-sectional view of the cover main body, and FIG. 6 is a perspective view showing a state in which a molded body of a bobbin and a stator yoke and a frame yoke are fitted into the cover main body. In addition, the same code | symbol is attached | subjected to the member corresponding to the prior art mentioned above.

  The electromagnetic actuator 1 of this embodiment shown in FIG. 1 is used for a motor-operated valve, and as shown in FIG. 3, a cylindrical resin bobbin 21 and an annular stator yoke 11 are integrated. An excitation coil 31 is wound around the outer periphery of the bobbin 21 to form a molded body 2, and the molded body 2 is fitted into a cylindrical frame yoke 41. The molded body 2 and the frame yoke 41 are accommodated in the case main body 51, and a space formed by the inner peripheral side of the case main body 51 and the outer peripheral side of the bobbin 21 is sealed with a casting resin 61.

  The stator yoke 11 is formed with a plurality of pole teeth 12 erected in the axial direction along the inner periphery of the stator yoke 11. The pair of upper and lower stator yokes 11, 11 has a bobbin 21 with these pole teeth 12. It is being fixed to the bobbin 21 so that it may mutually oppose along the inner peripheral surface.

  The bobbin 21 is formed integrally with the stator yoke 11, and a terminal 71 for supplying a current is press-fitted. The terminal 71 is connected to a lead wire 73 through a substrate 72. As shown in FIG. 3, a casting resin blocking rib 23 is provided on one end surface of the bobbin 21 around the opening of a through hole 22 into which a valve body (not shown) is inserted. Is formed. The casting resin blocking rib 23 is fitted into a fitting groove 52 in FIG. 5 formed on the bottom surface of the case main body 51 so that the bottom surface side of the case main body 51 is blocked in a liquid-tight state. The casting resin is poured from the 55 side.

  As shown in FIG. 6, the circumferentially continuous outflow prevention rib 24 protrudes from the end surface opposite to the end surface where the casting resin blocking rib 23 is formed so as to surround the opening of the through hole 22. Is formed. As shown in the figure, the casting resin has the projecting outer periphery of the outflow prevention rib 24 with the opening 55 of the case body 51 on the upper side and the end surface of the bobbin 21 on which the outflow prevention rib 24 is formed on the upper side. It is injected until the liquid level reaches the part.

  Thereby, resin sealing is performed up to the upper side of the metal members such as the coil 31, the stator yoke 11 and the frame yoke 41, and the casting resin is prevented from flowing out to the through hole 22 side.

  The frame yoke 41 is formed by winding a steel plate in a cylindrical shape, and as shown in FIG. 2, both end portions 42 of the steel plate face each other while being spaced apart from each other, and the side periphery of the cylinder is opened along the axial direction. It has become. As a result, the frame yoke 41 can be elastically deformed so that the cross section changes from the original shape, for example, so as to reduce the diameter.

  The case main body 51 is made of resin, and as shown in FIG. 5, a plurality of ribs 53 extending in the axial direction are provided in the circumferential direction of the inner peripheral surface on the back side (bottom surface portion side) of the inner peripheral surface. Protrusions are formed at intervals. The frame yoke 41 is pressed from the outside by the rib 53 and is fitted to the case main body 51 in a state where the frame yoke 41 is deformed in the diameter reducing direction.

As shown in FIG. 5, a plurality of protrusions 54 are formed in the vicinity of the opening 55 of the case body 51 at intervals in the circumferential direction of the inner peripheral surface, as shown in FIG. As shown, the frame yoke 41 with one end abutting against the bottom surface of the case body 51 has these protrusions 54 at the other end.
The frame yoke 41 is fixed to the case main body 51 in a predetermined positional relationship.

  As shown in FIG. 6, the molded body 2 of the stator yoke 11 and the bobbin 21 and the frame yoke 41 are accommodated in the case main body 51 in a state where the molded body 2 is disposed inside the frame yoke 41. In the state where the opening 22 of the case body 51 is on the upper side as shown in the figure, for example, urethane resin, epoxy resin or the like is poured into the space formed by the inner periphery side of the case body 51 and the outer periphery side of the bobbin 21. Pour mold resin and cure. Thereby, as shown in FIG. 1, the stator yoke 11, the frame yoke 41, the exciting coil 31, the terminal 71, the substrate 72, the lead wire 73, and the like are sealed with resin.

  The liquid casting resin injected between the case main body 51 and the bobbin 21 changes to a solid state as the curing reaction proceeds. At this time, the volume of the casting resin shrinks. Due to the contraction force of the casting resin between the frame yoke 41 and the stator yoke 11, the frame yoke 41 is deformed inward and is drawn along the outer peripheral portion of the stator yoke 11. As a result, the frame yoke 41 deforms and adheres along the outer peripheral portion of the stator yoke 11.

  As shown in FIG. 1, the casting resin 61 is filled up to the projecting outer peripheral portion of the outflow prevention rib 24, and the through hole 22 extends to the upper side of the metal members such as the excitation coil 31, the stator yoke 11, and the frame yoke 41. The resin is sealed without causing the resin to flow out to the side.

  In the present embodiment, the casting resin blocking rib 23 is fitted into the fitting groove 52 to block the bottom side in a liquid-tight manner, and the bobbin 21 is integrally formed with the stator yoke 11. The space to be injected is liquid-tightly sealed except for the upper side, and there is no need to use separate members such as a core mold and a holding jig during casting as in the prior art, and the bobbin 21 and the stator yoke 11 are not required. Further, the resin can be poured as it is in the state where the frame yoke 41 is housed in the case main body 51 to perform casting.

  FIG. 7 is a cross-sectional view showing an example of an electric valve using the electromagnetic actuator of the embodiment of FIG. As shown in the figure, the motor-operated valve body 81 is disposed in the through hole of the electromagnetic actuator 1, and the screw mechanism of the motor-operated valve body 81 is driven by electromagnetic action to open and close the valve. As shown in FIGS. 1 and 4, a bracket 56 is attached to the case main body 51, and the electric valve main body 81 is fixed by the bracket 56.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made without departing from the scope of the present invention. For example, each member such as the stator yoke 11, the frame yoke 41, the case main body 52, and the like can be used in an appropriate shape depending on the case. Further, the pair of stator yokes 11 facing each other may be one pair or two pairs.

FIG. 1 is a cross-sectional view showing an embodiment of the electromagnetic actuator of the present invention. FIG. 2 is a perspective view of the frame yoke. FIG. 3 is a perspective view of a molded body of the bobbin and the stator yoke. FIG. 4 is a perspective view of the cover body. FIG. 5 is a cross-sectional view of the cover body. FIG. 6 is a perspective view showing a state where a molded body of a bobbin and a stator yoke and a frame yoke are fitted into the cover body. FIG. 7 is a cross-sectional view showing an example of an electric valve using the electromagnetic actuator of the embodiment of FIG. FIG. 8 is a diagram for explaining a manufacturing process of a conventional electromagnetic actuator.

Explanation of symbols

1 Electromagnetic actuator 2 Assembly (molded body)
11 Stator yoke 12 pole tooth 21 bobbin 22 through hole 23 casting resin blocking rib 24 outflow preventing rib 31 exciting coil 41 frame yoke 42 end 51 case body 52 fitting groove 53 rib 54 protrusion 55 opening 56 bracket 61 Cast resin 71 Terminal 72 Substrate 73 Lead wire 81 Motorized valve body

Claims (2)

A pair of annular stator yokes with a plurality of pole teeth standing up along the inner circumference is fixed to the bobbin so that these pole teeth face each other, and an exciting coil is wound around the outer circumference of the bobbin And a magnetic circuit is formed by fitting the annular stator yoke to a cylindrical frame yoke,
An assembly composed of the frame yoke, the stator yoke and the bobbin is housed in the case main body, and casting resin is injected into a space formed by the inner peripheral side of the case main body and the outer peripheral side of the bobbin. An electromagnetic actuator in which the space is sealed with resin,
On one end surface of the bobbin, a casting resin blocking rib formed in a circumferential shape so as to surround an opening of a central through hole in which the pole teeth are disposed,
A circumferential groove is formed on the bottom surface of the case body, and includes a fitting groove fitted to the casting resin blocking rib,
By injecting the casting resin into the space formed by the inner peripheral side of the case body and the outer peripheral side of the bobbin by fitting the casting resin blocking rib into the fitting groove, An electromagnetic actuator characterized in that the bottom portion of the case body is liquid-tightly blocked from the outside.   An end surface of the bobbin opposite to the end surface where the casting resin blocking rib is formed is formed in a circumferential shape so as to surround the opening of the central through hole, and the inner peripheral side of the case body, the bobbin 2. The electromagnetic wave according to claim 1, further comprising an outflow prevention rib that prevents the casting resin from flowing out when the casting resin is injected into the space formed by the outer peripheral side of the casting resin. Actuator.

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