JPH07106120A - Secondary formation method for electromagnet device - Google Patents

Abstract

PURPOSE:To provide the secondary formation method for an electromagnet device which is high in dimensional accuracy and high in productivity and the manufacture of a mold for which is easy. CONSTITUTION:A spool 12, where a coil 16 is wound, is arranged inside the cavity 77 between molds 70 and 73. Resin material is injected directly from the gate 76 of the mold 73 into the positioning hole 15d provided in the spool 12 so as to position the spool with resin. Next, overflown resin material is charged in the cavity 77 for secondary molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet device, and more particularly to a method of secondary forming an electromagnet device incorporated in an electromagnetic relay.

[0002]

2. Description of the Related Art Conventionally, as an electromagnetic relay, for example, as shown in FIG. 18, a base block 1, a movable insulating base 2,
There is one including an electromagnet block 3 and a case 4.
As shown in FIGS. 19 and 20, the electromagnet block 3 has a permanent magnet 6 attached to an iron core 5 having a substantially U-shaped cross section.
This is obtained by winding the coil 8 on the spool 7 formed by insert molding of these, then covering the coil 8 by secondary molding, and insert-molding the fixed contact terminals 9, 9 (FIG. 21). ).

The positioning of the spool 7 during the secondary molding is performed by positioning pins (not shown) in the positioning holes 7a, 7b, 7c of the spool 7 shown in FIG.
It was inserted from the direction indicated by the arrow or by a clamp not shown.

[0004]

However, in the above-described method, the heat of the resin material injected during the secondary molding causes the pin,
Since the clamp is thermally expanded and deformed and the positioning accuracy of the pins and the like is lowered, the dimensional accuracy of the electromagnet block 3 is low.

In particular, when the resin portion of the spool 7 is supported by a clamp, the iron core 5 can only be indirectly positioned via the resin portion, and high positioning accuracy cannot be obtained. Therefore, the dimensional accuracy of the electromagnet block 3 is small. Was low.

Moreover, in the conventional method, since it is necessary to provide pins and the like inside the mold for secondary molding, the structure of the mold becomes complicated and it takes time to manufacture the mold.

Further, when the thickness of the iron core 5 and the outer dimension of the spool 7 are varied, for example, if the thickness of the iron core 5 is too large, the die presses the iron core 5. On the other hand, if the outer dimensions of the spool 7 are too small, the spool 7 may be deformed in the mold cavity.
Rattling occurred, and in each case the dimensional accuracy was low.

The electromagnet block 3 formed by the secondary molding has gate portions 3a and 3b directly connected to the gate of the mold.
Since (FIG. 21) is likely to be damaged when the mold is separated, it is necessary to make the gate portions 3a and 3b thick and the electromagnet block 3 has a complicated shape.

If the pins and clamps are used to support the secondary molding, the resin material cannot flow into the positioning holes 7a, 7b, 7c, etc., and the positioning holes 7a, 7b, 7c must be filled in a later step. There was a problem that productivity was low because it was troublesome twice.

In view of the above problems, it is an object of the present invention to provide a secondary molding method for an electromagnet device, which has high dimensional accuracy, easy mold production, and high productivity.

[0011]

In order to achieve the above-mentioned object, the present invention arranges a spool around which a coil is wound in a cavity of a molding die, and positions the spool on the spool from a gate of the molding die. The resin material is directly injected into at least one of the holes and positioned to fill the cavity with the resin material.

[0012]

Therefore, according to the present invention, the resin material injected from the gate of the mold flows into the positioning hole of the spool and is then filled in the cavity.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings of FIGS. The electromagnetic relay according to the present embodiment generally comprises a base block 20 formed by subjecting the electromagnet block 10 to secondary molding, a permanent magnet 30, an armature block 40, and a case 50.

As shown in FIGS. 5 and 6, the electromagnet block 10 is formed by winding a coil 16 around a spool 12 in which an iron core 11 having a substantially U-shaped cross section is insert-molded. For convenience of explanation, the coil 1 is shown in FIG.
6 is omitted.

The spool 12 is, as shown in FIG.
The magnetic pole surfaces 11a and 11b located at both ends of the iron core 11 are exposed from the upper end surfaces of the flange portions 13 and 14 formed at both ends, respectively, while the pair of relay terminals 17 are provided at the flange portions 13 and 14, 18 are insert-molded, and the barbed portions 17a and 18a thereof project from both end surfaces of the collar portions 13 and 14, respectively. A guide groove 13a is formed on the flange portion 13 along the side end surface thereof, and the flange portion 14 has a guide groove 14a similar to the guide groove 13a.
a is formed.

Further, an insertion hole 15a for inserting a permanent magnet 30, which will be described later, is formed in the central collar portion 15 provided at a position eccentric from the center of the spool 12, and the insertion hole 15a is sandwiched. Parallel guide groove 1
5b and 15c are provided. The bottom surface of the guide groove 15b is horizontal, and the bottom surface of the guide groove 15c is inclined.

Therefore, after one end of the coil 16 is twisted to the twisted portion 17a of the relay terminal 17 which is insert-molded in the collar portion 13, the coil 16 is placed along the guide groove 13a provided in the collar portion 13 and the spool 12 is wound. Of the desired number of windings, after winding about 20% of the desired number of windings, to the second body 12b along the guide groove 15b formed in the central collar portion 15. %) And then along the guide groove 15c of the central collar portion 15
The coil 16 is pulled out again to the body portion 12a and wound for 80% of the remaining number of turns.
After being twisted to 8a, the winding work of the coil 16 is completed by soldering to the twisted portions 17a and 18a.

According to this embodiment, the number of windings in the first winding operation of the coil 16 around the first body portion 12a is about 20.
%, And the remaining number of turns of the second winding is about 80%, so that the final winding end portion of the coil 16 is the first body portion 12.
The coil 16 is separated from the winding end portion of the coil 16 in the first winding operation by a predetermined distance. Therefore, even if the insulating coating of the coil 16 located on the outermost peripheral surface is slightly melted and peeled off by the heat of the resin material during the secondary molding described later, the coil 16 located on the outermost peripheral surface and the coil 16 located immediately below Since the voltage difference between the coil 16 and the coil 16 is small, there is an advantage that a short circuit is less likely to occur and the yield is improved.

In this embodiment, about 20% of the first body 12a is wound in the first winding operation, and then the second body 1 is wound.
After performing 100% winding work in 2b, the remaining about 80% winding work was performed again in the first body portion 12a, but not limited to this, for example, the first work in the first body portion 12a. In the winding operation, about 50% of the predetermined number of windings may be wound.

The base block 20 is formed by secondarily molding the electromagnet block 10 integrally with the lead frame 60. That is, the lead frame 60
As shown in FIG. 7, the fixed contacts 23a and 24a are fixedly integrated at a predetermined position of the hoop material, and punched out to form a coil terminal 21, a common terminal 22, a part of the fixed contact terminals 23 and 24,
Further, after forming the connection protrusions 62, the hatched portion of FIG. 7 is cut and bent (FIGS. 8 to 1).
0). Then, as shown in FIGS. 11 to 13, the lead frame 60 is inverted, the relay terminals 17 and 18 of the electromagnet block 10 are placed and positioned on the free ends of the coil terminals 21, respectively, and then laser welding is performed. Connect together.

Next, as shown in FIG. 14, the electromagnet block 10 integrated with the lead frame 60 is incorporated in the lower mold 70, and then the upper mold 73 is combined with the lower mold 70 to form the upper mold 73. Positioning members 74, 7 assembled to
By locking the corner portion of the iron core 11 with 4, the insertion hole 15a of the electromagnet block 10 is fitted into the positioning pin 71 protruding from the lower mold 70, and the magnetic pole surface 11 of the iron core 11 is fitted.
The electromagnet block 10 is positioned in the cavity 77 by abutting the a and 11b with the ejecting pins 72 and 72.

The runner 75 provided on the upper die 73
The resin material melted from the gate 76 of the electromagnet block 10
Is injected into the injection hole 15d of the electromagnet block 10 by resin pressure.
Is pressed against the lower mold 70 to firmly position it, and the resin material overflowing from the injection hole 15d is removed by the cavity 77.
The base block 20 is formed by filling the inside. Next, after pulling down the lower mold 70, the iron core 11 is ejected by the ejecting pins 72, 72 to obtain the base block 20 (FIG. 16). By the above-described secondary molding, the upper edge of the outer surface of the base block 20,
A continuous fitting surface 25 shown by hatching in FIG. 1 is formed, and an inclined surface 26 for guiding a sealing material is formed at a lower edge portion of the outer surface thereof.

In this embodiment, the positioning pin 71 is provided substantially on the same axis as the gate 76, and the iron core 11 is not deformed in the plate thickness direction, so that high dimensional accuracy can be obtained. In particular, for example, when the electromagnet block 10 is composed of an approximately U-shaped iron core 11 having a width of about 2 mm, a plate thickness of about 2 mm, and a length of about 15 mm, deformation in the plate thickness direction can be effectively prevented. There is an advantage that high dimensional accuracy can be secured.

In the above-described embodiment, the electromagnet block 10 is moved to the lower mold 7 by the positioning members 74 and 74 provided on the upper mold 73.
The case where the initial positioning is set to 0 and the positioning is firmly performed by the resin pressure of the resin material injected from the gate 76 of the runner 75 has been described, but the invention is not limited to this, and as shown in FIG. Gate 7 of runner 75 provided
6, and the electromagnet block 10 may be pressed against the lower die 70 by the resin pressure of the resin material injected from the gates 79, 79 of the runners 78, 78 for firm positioning.

Next, as shown in FIG. 17, the lead frame 60 integrated with the base block 20 obtained by the secondary molding is pressed to cut out the coil terminal 21, the common terminal 22, and the fixed contact terminals 23 and 24. The base block 20 is completed by bending the tips of the terminals downward and further bending the terminals downward from the base.

According to the present embodiment, since the connecting protrusion 62 of the lead frame 60 is insert-molded on the outer surface of the base block 10, the base block 20 can be cut even if the terminals 21, 22, 23 and 24 are cut. Lead frame 60
It can be transported together with the lead frame 60 without falling off. Moreover, the common terminal 22 has a substantially T-shaped connection receiving portion 2
Since the anchor projection 22b (FIGS. 8 and 9) extending from 2a is insert-molded on the outer wall of the base block 10, the common terminal 22 protruding from the outer surface of the base block 10 is bent from its base. However, there is an advantage that the common terminal 22 does not rattle.

In the above embodiment, each terminal 21, 22, 2
Although the case where the tip end portions of 3, 24 are bent inward in advance has been described, the present invention is not limited to this, and may be bent outward in advance, or they may be sealed with a sealing material 80 described later, It may be bent inward or outward after preliminary soldering. Bending the tip of each terminal inward has the advantage of reducing the floor area and increasing the packing density, while bending the tip of each terminal outward prevents soldering. There are advantages that it is easy and the adhesion reliability is high.

The permanent magnet 30 has a substantially rectangular parallelepiped shape formed by sintering rare earth, is inserted from above into the insertion hole 15a of the electromagnet block 10 supported by the lead frame 60, and has a magnetic pole surface below it. After assembling 31 so as to contact the upper surface of the iron core 11, it is magnetized.

As shown in FIG. 1, the armature block 40 has movable contact pieces 42, 42 arranged in parallel on both sides of an armature 41.
Is integrally formed with the support portion 43.

The armature 41 is a flat rectangular plate material made of a magnetic material, and a support projection 41c is formed in the center of the lower surface of the plate by a protrusion process (FIG. 3).

The movable contact pieces 42, 42 are 2 in the width direction.
It has a twin contact structure in which movable contacts 42a and 42b are respectively provided at the divided both ends. The movable contact pieces 42, 42 extend laterally from a central portion thereof with a substantially T-shaped connecting portion 42c, and the connecting portion 42c projects from the side surface of the supporting portion 43.

The supporting portion 43 is provided with the armatures 4 arranged side by side.
1 and the movable contact pieces 42, 42 are resin-molded articles that are insert-molded and integrated with each other, and the support protrusion 41c of the iron core 41 is exposed from the central portion of the lower surface thereof.

Therefore, the armature block 40 is inserted from above the base block 20 supported by the lead frame 60.
, The support protrusion 41c of the armature 41 is placed on the magnetic pole surface 32 of the permanent magnet 30, and the connecting portion 42c is connected to the common terminal 22.
By positioning and laser welding the connection receiving portion 22a of the armature 41, the both end portions 41a and 41b of the armature 41 are attached to the iron core 1.
The magnetic pole surfaces 11a and 11b of No. 1 are alternately contacted and separated, and
The movable contacts 42a and 42b alternately contact and separate from the fixed contacts 23a and 24a.

In this embodiment, since the supporting protrusion 41c of the armature 41 is positioned at a position eccentric from the center of the magnetic pole surface 32 of the permanent magnet 30, the left-right magnetic balance is lost and self-recovery occurs. It is a type.

The case 50 is a box-shaped resin molded product that can be fitted into the base block 20 incorporating the armature block 40, and the coil terminals 21, 2 are provided at the opening edge portions thereof.
1. Notches 51, 51, 52, 53, 54 that fit into the common terminal 22 and fixed contact terminals 23, 24 are formed, and gas vent holes 55 are formed in the corners of the ceiling surface.

When the case 50 is partially fitted into the base block 20 supported by the lead frame 60 and pushed down, the base block 20 is detached from the connection protrusions 62, 62 of the lead frame 60, and then, The case 50 is completely fitted to the base block 20, the intermediate portions of the terminals 21 to 24 are fitted to the cutout portions 51 to 54 of the case 50, and the outer surface of the intermediate portion of each of the terminals 21 to 24 is the case 50. Is flush with the outer surface of. However, Case 5
Since the height dimension of 0 is smaller than the height dimension of the base block 20, the bottom portion of the base block 20 projects from the opening of the case 50, and the inclined surface 26 provided on the side edge portion near the bottom surface of the base block 20 is exposed. To do.

In this embodiment, since the connecting protrusions 62 are not cut, there is an advantage that cutting chips generated by cutting do not mix into the base block 20.

In the above embodiment, the case where the base block 20 is detached from the connection protrusion 62 by separation is explained, but the present invention is not limited to this, and the connection protrusion 6 is not limited to this.
2 may be deeply insert-molded into the base block 20, and the connection protrusion 62 may be cut to separate the base block 20.

Next, as shown in FIG. 4, when the sealing material 80 is injected toward the inclined surface 26 formed near the bottom surface of the base block 20, the sealing material 8 is provided along the inclined surface 26.
0 flows down and seals the gap between the base block 20 and the case 50. However, the continuous fitting surface 25 provided on the outer surface of the base block 20 abuts on the inner side surface corner of the case 50 to prevent the sealing material 80 from entering the base block 20.

Then, after the internal gas is sucked from the gas vent hole 55 of the case 50, the assembly work is completed by heat sealing.

Next, the operation of the electromagnetic relay having the above structure will be described. First, in the case of non-excitation, since the left and right magnetic balance is lost, one end portion 41a of the armature 41 is
Is attracted to the magnetic pole surface 11a of the iron core 11, and the movable contact 42a of the movable contact piece 42 is in contact with the fixed contact 23a, while the movable contact 42b is separated from the fixed contact 24a.

When a voltage is applied to the coil 16 to excite the electromagnet block 10 so that a magnetic flux is generated in a direction in which the magnetic force of the permanent magnet 30 is canceled out, the armature 41 resists the magnetic force of the permanent magnet 30 and the supporting protrusion 41 is supported. 41c is rotated about a fulcrum, and one end portion 41a of the armature 41 is connected to the magnetic pole surface 11 of the iron core 11.
a, and then the movable contact 42a moves to the fixed contact 23.
After being separated from a and the movable contact 42b contacts the fixed contact 24a, the other end 41b of the armature 41 is attracted to the magnetic pole surface 11b of the iron core 11.

Further, when the excitation of the coil 16 is released,
Since the left and right magnetic balance is lost, the magnetic force of the permanent magnet 30 causes the armature 41 to perform the opposite operation to the above, and the armature block 40 rotates to return to the original state.

[0044]

As is apparent from the above description, according to the secondary molding method of the present invention, the spool is accurately positioned in the cavity of the mold by the resin pressure of the resin material injected from the gate of the mold. Therefore, the positioning pin and the clamp as in the conventional example are not required, and the deterioration of the dimensional accuracy due to the thermal expansion of these can be eliminated. In particular, because the spool is pressed against the reference surface of the mold by the resin pressure of the molten resin material for positioning, not only is a clamp or the like unnecessary, but also flexible positioning is possible, and it is possible to position at the optimum part. Accuracy is improved. Moreover, since it is not necessary to provide pins and clamps, the internal structure of the mold is simplified and the mold is easily manufactured. Furthermore, since the molten resin material positions the spool by pressing it against the reference surface of the mold, even if there are variations in the dimensional accuracy of the spool, etc.
Since there is no deformation of the spool or the like as in the conventional example or rattling does not occur in the cavity, the dimensional accuracy is further improved. Further, since the resin material flows into the cavity from the gate of the mold through the positioning hole, the gate part of the electromagnet device continuous with the gate of the mold becomes a very thick resin part. Therefore, it is not necessary to separately provide a thick resin portion as in the conventional example, and the shape of the electromagnet device is simplified. Then, since the secondary molding resin material flows into and fills the positioning holes of the spool or the like, there is no need to fill the positioning holes in a later step, and there is an effect that productivity is improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of an electromagnetic relay according to the present invention.

FIG. 2 is a partial plan view of the electromagnetic relay shown in FIG.

3 is a front partial cross-sectional view of the electromagnetic relay shown in FIG.

4 is a left side partial cross-sectional view for explaining a sealing operation of the electromagnetic relay shown in FIG.

FIG. 5 is a perspective view showing an electromagnet block of the electromagnetic relay according to the present invention.

6 is a cross-sectional view of the electromagnet block shown in FIG.

FIG. 7 is a plan view of a lead frame used for manufacturing the electromagnetic relay according to the present invention.

8 is a plan view showing a state where the lead frame of FIG. 7 is bent.

9 is a front view of the lead frame shown in FIG. 8. FIG.

10 is a right side view of the lead frame shown in FIG.

FIG. 11 is a plan view showing a state in which an electromagnet block is placed on a lead frame used for manufacturing the electromagnetic relay according to the present invention.

FIG. 12 is a front view of the lead frame shown in FIG.

13 is a left side view of the lead frame shown in FIG.

FIG. 14 is a cross-sectional view showing a secondary molding method performed when manufacturing the electromagnetic relay according to the present invention.

FIG. 15 is a cross-sectional view showing a method different from the secondary molding shown in FIG.

FIG. 16 is a perspective view showing a base block formed by secondary molding according to the present invention.

FIG. 17 is a perspective view showing a state in which a base block formed by secondary molding according to the present invention has been subjected to press working.

FIG. 18 is an exploded perspective view showing an example of an electromagnetic relay according to a conventional example.

FIG. 19 is a plan view of a spool according to a conventional example.

FIG. 20 is a partial cross-sectional view of a spool according to a conventional example.

FIG. 21 is a bottom view showing an electromagnet block subjected to secondary molding according to a conventional example.

[Explanation of symbols]

10 ... Electromagnet block, 12 ... Spool, 15d ... Positioning hole, 16 ... Coil, 70, 73 ... Mold, 76 ...
Gate, 77 ... Cavity.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Yamada 10 Ouron Co., Ltd.

Claims (1)

[Claims] 1. A spool around which a coil is wound is arranged in a cavity of a molding die, and a resin material is directly injected from a gate of the molding die into at least one of positioning holes provided in the spool for positioning. Meanwhile, a secondary molding method for an electromagnet device is characterized in that the cavity is filled with a resin material.