JPWO2010076877A1 - Manufacturing method of solenoid core - Google Patents

Abstract

In a method for manufacturing a solenoid core using a strip-shaped steel plate as a material for a core piece, high accuracy is realized in the outer dimension of the core piece. A method for manufacturing a solenoid core according to the present invention is a method for manufacturing a solenoid core comprising a U-shaped fixed core piece 1 and a movable core piece 2 to be disposed opposite to both end faces of the fixed core piece 1. A core winding step for manufacturing the annular core 13 by winding a belt-shaped steel plate in an annular shape, and a mold for manufacturing the annular mold core 18 by covering the surface of the manufactured annular core 13 with a mold resin. And a cutting step of dividing the produced mold core 18 into two to obtain the fixed core piece 1 and the movable core piece 2.

Description

  The present invention relates to a method for manufacturing a solenoid core comprising a fixed core piece and a movable core piece.

For example, as shown in FIG. 2, a solenoid used for a solenoid valve or the like includes a U-shaped fixed core piece (10) and a movable core piece (20) disposed opposite to both end faces of the fixed core piece (10). ) And a pair of coils (30) and (30) wound around two parallel arms of the fixed core piece (10), and the movable core piece (20) is unidirectional by springs (6) and (6). The load (7) is connected to the movable core piece (20).
In the solenoid, the load (7) such as a valve is reciprocated by turning on / off the energization to the coils (30) (30).

  In conventional solenoids, electromagnetic soft iron or electromagnetic stainless steel is generally used as a material for the fixed core piece (10) and the movable core piece (20) (see Patent Document 1), and a block made of such a material is used. The fixed core piece (10) and the movable core piece (20) are produced by cutting into a predetermined shape.

JP 2008-169451 A

  When a solenoid is used as, for example, an electromagnetic valve, an ultra-high speed switching operation may be required. However, in the conventional solenoid using electromagnetic soft iron or electromagnetic stainless steel as the core material, the holding power of these materials is as high as about 80 (A / m), and the maximum permeability is as small as about 1000 to 2500. There is a problem that the responsiveness is low, the suction force is not sufficiently large, and sufficient operation performance cannot be obtained.

Accordingly, it is conceivable to employ a directional silicon steel sheet having a low holding force of about 10 (A / m) and a maximum magnetic permeability of about 7000 as the core material.
When producing a core piece using such a strip-shaped steel plate, after producing an annular core by winding the steel plate around the jig in an annular shape, the annular core is cut at the center to obtain two pieces. A U-shaped core piece is obtained, and one of the core pieces is used as a fixed core piece.

However, in an annular core formed by annularly winding a belt-shaped steel plate, the steel plate swells due to the spring back, so that there is a problem that the accuracy of the outer dimensions in the completed state is poor and a core piece of a predetermined shape cannot be obtained. .
Moreover, since the core piece obtained by cutting | disconnecting an annular core becomes what laminated | stacked several steel plates, there exists a problem which the steel plate of a surface layer turns up with a cutting | disconnection.
In this way, the core piece having a large error in the outer dimensions causes the solenoid to become large and have a low reliability.

  Therefore, an object of the present invention is to achieve high accuracy in the outer dimension of the core piece in a method for manufacturing a solenoid core using a strip steel plate as a material for the core piece.

The method for manufacturing a solenoid core according to the present invention comprises a U-shaped fixed core piece (1) and a movable core piece (2) to be arranged to face both end faces of the fixed core piece (1). A method of manufacturing a solenoid core, comprising:
A core winding process for producing the annular core (13) by winding the belt-shaped steel sheet in an annular shape;
A molding step for producing an annular mold core (18) by covering the surface of the produced annular core (13) with a mold resin;
A cutting step of dividing the produced mold core (18) into two to obtain the fixed core piece (1) and the movable core piece (2);

In the method for manufacturing a solenoid core according to the present invention, after the annular core (13) is produced by the core winding process, the surface of the annular core (13) is covered with a mold resin. In the state of the core (18), the annular core (13) is hardened from the periphery by the mold resin. Therefore, the steel plate constituting the annular core (13) does not swell due to the spring back.
Further, in the process of cutting the mold core (18) by the cutting process to obtain the fixed core piece (1) and the movable core piece (2), the annular core (13) constituting the mold core (18) is molded resin. Therefore, the surface steel plate of the mold core (18) is not turned up.
As a result, high accuracy can be obtained in the external dimensions of the fixed core piece (1) and the movable core piece (2).

In a specific configuration, a directional silicon steel plate is used as the steel plate in the core winding step.
The grain-oriented silicon steel sheet has a low holding force of about 10 (A / m) and a maximum magnetic permeability of about 7000. Therefore, the directional silicon steel sheet has a high response and a sufficiently large attractive force. The solenoid using (1) and the movable core piece (2) has sufficient operating performance.

In a more specific configuration, in the molding step, the entire surface of the annular core (13) is covered with a mold resin having a substantially uniform thickness to obtain a mold core (18) having a predetermined outer dimension.
As a result, not only high accuracy can be obtained in the outer dimensions of the mold core (18), but also an effect excellent in rust prevention and electrical insulation can be obtained.

The annular core (13) has an annular shape having four arcuate corners. In the cutting step, the vicinity of two arcuate corners adjacent to each other is set as a cutting position.
In the annular core (13) having four arcuate corners, the steel plates are stacked closely together, particularly at the four arcuate corners. By cutting, a particularly high dimensional accuracy can be obtained in the facing portion of the fixed core piece (1) and the movable core piece (2).

Further, after the annular core (13) produced by the core winding process is annealed, the molding process is performed.
The annular core (13) has a large distortion at its corners, but the annealing of the annular core (13) eliminates the deterioration of the characteristics due to the large distortion at the corners.

Another method for manufacturing a solenoid core according to the present invention is as follows.
A core winding process for producing the annular core (13) by winding the belt-shaped steel sheet in an annular shape;
A molding step for producing an annular mold core (18) by covering the surface of the produced annular core (13) with a mold resin;
And cutting the produced mold core (18) into two to obtain two fixed core pieces (1) (1).

  According to the method for manufacturing a solenoid core of the present invention, the mold core (18) is formed in the process of cutting the mold core (18) by the cutting process to obtain two fixed core pieces (1) (1). Since the annular core (13) is solidified from the periphery by the mold resin, the steel sheet of the surface layer of the mold core (18) is not turned up. As a result, high accuracy can be obtained in the external dimensions of the fixed core piece (1).

  According to the method for manufacturing a solenoid core according to the present invention, high accuracy can be realized in the outer dimension of the core piece even when a strip-shaped steel plate is used as the material of the core piece.

FIG. 1 is a partially cutaway side view of a solenoid using a fixed core piece and a movable core piece according to the present invention. FIG. 2 is a partially cutaway side view of a conventional solenoid. FIG. 3 is a process diagram showing a method for manufacturing a solenoid core according to the present invention. FIG. 4 is a diagram for explaining each step in the first half of the manufacturing method. FIG. 5 is a diagram for explaining each step in the latter half of the manufacturing method. FIG. 6 is a partially cutaway side view of another solenoid using the fixed core piece according to the present invention. FIG. 7 is a process diagram showing the second half of the method for manufacturing a solenoid core according to the present invention.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 shows a solenoid having a fixed core piece (1) and a movable core piece (2) manufactured by the method for manufacturing a solenoid core according to the present invention, and has a U-shaped fixed core piece (1). And the movable core piece (2) arranged with a predetermined gap between both end faces of the fixed core piece (1), the respective surfaces are covered with the mold resin (4) (5). .

A pair of coils (3) and (3) are wound around a pair of parallel arms of the fixed core piece (1). The movable core piece (2) is biased in one direction by springs (6) and (6), and a load (7) is connected to the movable core piece (2).
In the solenoid, the coil (3) (3) is turned on / off to reciprocate the movable core piece (2) to drive the load (7) such as a valve.

FIG. 3 shows a series of steps P1 to P6 for manufacturing the fixed core piece (1) and the movable core piece (2).
In the process P1, as shown in FIG. 4A, a core material (11) is prepared in which a directional silicon steel sheet having a certain thickness is wound in a roll shape.
In the process P2, as shown in FIG. 4B, while rotating the jig (12), the steel plate is unwound from the core material (11), and the steel plate is wound around the prismatic jig (12). An annular core (13) having one arcuate corner and four linear parts connecting two arcuate corners adjacent to each other is produced.

In step P3, as shown in FIG. 4C, the annular core (13) is accommodated in an electric furnace (14) provided with a heater (15), and the annular core (13) is annealed.
As a result, the internal strain generated at the four corners of the annular core (13) is relaxed, and the magnetic properties are restored.

Thereafter, in step P4, as shown in FIG. 5A, the annular core (13) is immersed in the impregnating resin liquid (16), and the annular core (13) is impregnated with varnish.
As a result, the varnish penetrates between the layers of the laminated steel plates constituting the annular core (13), and the bonding strength between the layers of the laminated steel plates is increased.

In step P5, as shown in FIG. 5 (b), the annular core (13) is insert-molded (resin-sealed), and the entire surface of the annular core (13) is formed by a mold resin (17) having a substantially uniform thickness. An annular mold core (18) having a predetermined outer dimension is obtained by covering.
With such an insert mold, a high dimensional accuracy can be obtained for the mold core (18).

In step P6, as shown in FIG. 5 (c), the two linear portions of the mold core (18) extending in parallel with each other are positioned near the arcuate corners (more specifically, the linear portion of the core and the circular portion). At the boundary of the arc-shaped part), the cutter (19) divides it into two, and as shown in FIG. 5 (d), the U-shaped fixed core piece (1) and the I-shaped movable core piece (2) obtain.
In cutting the mold core (18), since the annular core (13) is hardened from the periphery by the mold resin (17), the laminated steel sheet constituting the annular core (13) does not peel off and has a high dimension. Accuracy is maintained.

The solenoid shown in FIG. 1 is assembled using the fixed core piece (1) and the movable core piece (2) thus obtained.
In this solenoid, a directional silicon steel plate is used as the material of the fixed core piece (1) and the movable core piece (2), so that the response is higher than that of the conventional solenoid made of soft iron. A large suction force can be obtained. Therefore, high operating characteristics can be realized as a solenoid for driving a solenoid valve or the like at high speed.

  Moreover, since the fixed core piece (1) and the movable core piece (2) are entirely covered with the mold resin (4) (5) having a substantially constant thickness, high dimensional accuracy can be obtained in the outer shape. In addition, a rust prevention effect and high electrical insulation can be obtained.

  FIG. 6 shows a solenoid having a fixed core piece (1) and a movable core piece (8) manufactured by another method for manufacturing a solenoid core according to the present invention, and has a U-shaped fixed core piece ( The surface of 1) is covered with the mold resin (4).

A pair of coils (3) and (3) are wound around a pair of parallel arms of the fixed core piece (1). The movable core piece (8) is biased in one direction by springs (6) and (6), and a load (7) is connected to the movable core piece (2).
In the solenoid, the coil (3) (3) is turned on / off to reciprocate the movable core piece (8) to drive the load (7) such as a valve.

  In the production of the fixed core piece (1), the annular core (13) subjected to the annealing is manufactured in the same manner as the steps P1 to P3 shown in FIGS. The annular core (13) is impregnated with varnish in the same manner as in Step P4 shown in FIG.

  Thereafter, in step P5, as shown in FIG. 7A, an insert mold is applied to the annular core (13), and the entire surface of the annular core (13) is covered with a mold resin (17) having a substantially uniform thickness. An annular mold core (18) having the following outer dimensions is obtained.

Next, in step P6 ′, as shown in FIG. 7B, the mold core (18) is divided into two by the cutter (19) at the center position of the linear portion connecting the two arcuate corners adjacent to each other. As shown in FIG. 7C, two U-shaped fixed core pieces (1) and (1) are obtained.
In cutting the mold core (18), since the annular core (13) is hardened from the periphery by the mold resin (17), the laminated steel sheet constituting the annular core (13) does not peel off and has a high dimension. Accuracy is maintained.

  Of the two fixed core pieces (1) and (1) obtained in this way, either one of the fixed core pieces (1) and a separately produced movable core piece (8) are shown in FIG. Assemble the solenoid. The movable core piece (8) can be produced, for example, by laminating flat steel plates.

  In the solenoid, a directional silicon steel plate is used as the material of the fixed core piece (1). Therefore, the solenoid is more responsive than the conventional solenoid made of soft iron, and a large suction force can be obtained. Therefore, high operating characteristics can be realized as a solenoid for driving a solenoid valve or the like at high speed.

  Moreover, since the fixed core piece (1) has its entire surface covered with the mold resin (4) having a substantially constant thickness, not only high dimensional accuracy can be obtained in the outer shape, but also the rust prevention effect and high electrical resistance. Insulation is obtained.

  In addition, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim. For example, the steel plate used as the material of the annular core (13) is not limited to the directional silicon steel plate, and a known steel plate having the same characteristics as the directional silicon steel plate can be employed.

(1) Fixed core piece
(2) Movable core piece
(3) Coil
(4) Mold resin
(5) Mold resin
(11) Core material
(12) Jig
(13) Ring core
(14) Electric furnace
(17) Mold resin
(18) Mold core
(19) Cutter

Claims (8)

In a method for manufacturing a solenoid core comprising a U-shaped fixed core piece and a movable core piece to be arranged opposite to both end faces of the fixed core piece,
A core winding process for producing an annular core by winding a belt-shaped steel sheet in an annular shape;
A molding step of producing an annular mold core by covering the surface of the produced annular core with a mold resin;
Cutting the produced mold core to obtain the fixed core piece, and assembling the solenoid core by combining the fixed core piece and the movable core piece obtained in the cutting step. A method for manufacturing a solenoid core.   2. The method for manufacturing a solenoid core according to claim 1, wherein in the cutting step, the produced mold core is divided into two to obtain one fixed core piece and one movable core piece.   The annular core has an annular shape having four arcuate corners and four linear parts connecting two arcuate corners adjacent to each other. In the cutting step, the two linear parts extending in parallel to each other are formed. The method for manufacturing a solenoid core according to claim 2, wherein the solenoid core is cut at positions near the arcuate corners.   2. The method for manufacturing a solenoid core according to claim 1, wherein in the cutting step, the produced mold core is divided into two to obtain two fixed core pieces.   The annular core has an annular shape having four arcuate corners and four linear parts connecting two arcuate corners adjacent to each other. In the cutting step, the two linear parts extending in parallel to each other are formed. The method for manufacturing a solenoid core according to claim 4, wherein the solenoid core is cut at a position that bisects each.   The method for manufacturing a solenoid core according to any one of claims 1 to 5, wherein a directional silicon steel plate is used as the steel plate in the core winding step.   The solenoid core according to any one of claims 1 to 6, wherein in the molding step, a mold core having a predetermined outer dimension is obtained by covering the entire surface of the annular core with a mold resin having a substantially uniform thickness. Core manufacturing method.   The method for manufacturing a solenoid core according to any one of claims 1 to 7, wherein the molding step is performed after the annular core produced by the core winding step is annealed.

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