JP2000061986A - Resin molding mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding mold which seals an object to be sealed in a resin molding and extracts a wire rod drawn out from the object outside the molding for molding. SOLUTION: A lead wire 14a is arranged in a lead wire passage channel 12a formed in a core block at an extraction position for extracting the lead wire 14a outside a mold, the cavity projection part 13a of a cavity block is inserted into the channel 12a by closing the mold, the lead wire 14a formed from twisted wires is compressed, and solid wires constituting the twisted wire are dispersed to fill a lead wire passage space S. Since only narrow clearances between the solid wires remain in the space S, and a prescribed width in the lead wire passage direction is formed, a resin is solidified before leakage to be prevented from flowing outside the mold.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of sealing a component of an electric product in a resin molded product and forming a wire such as a lead wire drawn out of the component into a resin. The present invention relates to a resin molding die that can be pulled out of a molded product and subjected to insert molding. 2. Description of the Related Art In insert molding for sealing an object to be sealed in a resin molded product, when the object to be sealed is a component of an electric product, a lead wire or the like drawn from the component is used. Need to be drawn out of the resin molded product. In such a case, a space for drawing out the wire is formed on the parting surface between the core block and the cavity block of the molding die, and the mold is closed with the wire drawn out of the space from this space. Insert molding of the object to be sealed is performed. [0003] However, if the wire drawn out of the mold is formed into a fixed outer shape such as a single wire, a space is formed on the parting surface in accordance with the shape. Although it can be formed, if the wire to be drawn is a stranded wire obtained by twisting a plurality of thin wires, the outer shape is not constant, and there is a space between the thin wires constituting the stranded wire, and the wire drawing position There is a problem that it is not possible to completely prevent the resin from leaking out of the mold. In addition, since the outer shape of the stranded wire is not constant, it is difficult to set the cross-sectional area of the space through which the stranded wire passes, and it is difficult to prevent leakage of the resin without damaging the stranded wire. . [0004] It is an object of the present invention to provide a resin molding die capable of pulling out a stranded wire drawn from an object to be sealed out of the die and performing insert molding. [0005] In order to achieve the above object, the present invention provides a method for sealing an object to be sealed in a molded article which is formed by resin molding by injection molding, and pulling out the object from the object to be sealed. In a resin molding die for drawing a wire material out of a molded product and performing resin molding, the wire material is formed of a stranded wire obtained by twisting a plurality of thin wires, and a wire passing position for pulling the wire material out of the mold In the parting surface between the cavity block and the core block, the wire cross-sectional area / space cross-sectional area is 0.3 to 0.5.
The width of the wire passing direction is 5 to 15 mm
It is characterized in that it is formed so that According to this configuration, the ratio of the cross-sectional area of the wire drawing space formed on the parting surface at the position where the stranded wire is drawn out of the mold to the cross-sectional area of the wire is set to the above-mentioned numerical value. Even if the resin tries to flow out of the mold from the gap, the gap is narrow, and by setting the width of the parting surface to the above value, it solidifies before flowing out of the mold. Resin is prevented from leaking. Further, since the space cross-sectional area at the position where the wire is pulled out is larger than the cross-sectional area of the wire, the wire is not damaged. An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention. In the resin molding die according to the present embodiment, an electromagnetic induction coil of a rice cooker by electromagnetic induction heating is sealed in a resin, and a lead wire drawn from the electromagnetic induction coil is drawn out of a resin molded product. It is configured to be insert-molded. As shown in FIG. 1, the electromagnetic induction coil 2
Winds a wire formed of a stranded wire in a state of being separated into an inner coil 2a and an outer coil 2b, and from the winding start position and the winding end position, respectively, leads 14a,
14b is drawn out. This electromagnetic induction coil 2 is disposed at the bottom of the pot of the rice cooker,
It is used for induction heating of a pan made of an iron-based material by high-frequency power supplied from a and 14b. As shown in FIG. 2, the electromagnetic induction coil 2 has a bowl shape as shown in FIG. The resin is sealed in the resin molded portion 10 of the formed insert molded product 1. In the resin molding section 10, together with the electromagnetic induction coil 2, as shown in FIG.
The ferrite core 3 is resin-sealed in some places. FIGS. 3 and 4 show a configuration of a mold for resin-molding the insert-molded article 1. In FIG. 3, a line C-A from the center point C shown in FIG. This is shown by a 断面 section of each of the CB lines at the positions not shown. As shown in FIG. 3, a concave portion 4 for accommodating the ferrite core 3 is formed in a core block 12 constituting a resin molding die. A member is provided, and the ferrite core 3 placed in the concave portion 4 is adsorbed by the positioning member and positioned and fixed on the core block 12.
After disposing the ferrite core 3, the electromagnetic induction coil 2 is placed at a predetermined position on the core block 12, as shown in FIG. When the electromagnetic induction coil 2 is mounted on the core block 12, the lead wires 14a and 14b are accommodated in grooves formed in the core block 12. After the ferrite core 3 and the electromagnetic induction coil 2 are disposed on the core block 12 and the mold is closed, the ferrite core 3 and the electromagnetic induction coil 2 are placed between the core block 12 and the cavity block 13. The resin-filled space 11 is accommodated therein. By injecting the resin supplied from the sprue 7 into the resin filling space 11 from the gate 8 in the horizontal direction, the resin filling space 11 is filled with the resin.
The insert block 1 is formed by sealing the core block 12 and the cavity block 13 with resin. FIG. 5 shows a die structure at a position where the lead wires 14a and 14b are pulled out. The lead wires 14a and 14b are arranged in lead wire grooves 12a and 12b formed in the core block 12, respectively. When the mold is pulled out of the mold and the mold is closed, the cavity protrusion 13 formed in the cavity block 13 is formed in the lead wire passage grooves 12a and 12b.
a, 13b fit into the lead wire passing space S formed at the bottom of the lead wire passing grooves 12a, 12b.
a and 14b are accommodated in a compressed state. FIG. 6 is an enlarged view of the lead wire passing space S, and has a radius of 3.5.
mm cavity protrusions 13a, 13b
Is cut off at a height of 1 mm to form a lead wire passing space S having a cross-sectional area of 3.372 mm ² . The lead wires 14a and 14b accommodated in the lead wire passing space S are formed as stranded wires obtained by twisting a plurality of thin single wires, and are compressed by the cavity projections 13a and 13b to form the lead wire passing space S. Each of the single wires is dispersed to fill the lead wire passing space S in a state where a slight gap is left between the single wires. These lead wires 14a, 14b
The cross-sectional area of the lead wire obtained by summing the cross-sectional areas of the single wires of each of the stranded wires is 1.413 mm ² , and the cross-sectional area of the wire / space is 0.419. It has been confirmed that a desired effect can be obtained by configuring the wire cross-sectional area / space cross-sectional area to be in the range of 0.3 to 0.5. As shown in FIG. 7, the width W in the lead-through direction of the lead-through direction formed by the lead-through grooves 12a and 12b in which the lead-through space S is formed and the cavity protrusions 13a and 13b. When the resin is formed into a size of 5 to 15 mm, even if the resin tries to flow out of the mold through the gap in the lead wire passing space S, the resin solidifies while flowing out the minute gap to the width W in the lead wire passing direction. It does not leak out of the mold. Therefore, even if the lead wires 14a and 14b formed by stranded wires are drawn out of the insert molded product 1 from the electromagnetic induction coil 2 sealed in the insert molded product 1, The resin does not leak from the draw-out position. As described above, according to the present invention, an object to be sealed is sealed in a resin molded product, and a stranded wire is formed from the sealed object to the outside of the resin molded product. Even if it is pulled out and insert molded, the resin does not leak from the lead wire drawing position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a form of an electromagnetic induction coil according to an embodiment. FIG. 2 is a cross-sectional view of an insert molded product molded by resin-sealing an electromagnetic induction coil. FIG. 3 is a molding structural view showing a molding state by a cross section taken along line C-A in FIG. 1; FIG. 4 is a molding structure diagram showing a molding state by a cross section taken along line CB of FIG. 1; FIG. 5 is a cross-sectional view showing a mold configuration at a lead wire withdrawal position. FIG. 6 is an enlarged sectional view of a lead wire passing space S. FIG. 7 is a cross-sectional view illustrating the width of the lead wire passing space S; [Description of Signs] 1 Insert molded product 2 Electromagnetic induction coil (object to be sealed) 11 Resin filled space 12 Core block 13 Cavity blocks 14a, 14b Lead wire S Lead wire passing space W Width of lead wire passing direction

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yasuhito Miyake             Matsushita Electric Industrial Co., Ltd.             Sangyo Co., Ltd. (72) Inventor Kimio Yamashita             Matsushita Electric Industrial Co., Ltd.             Sangyo Co., Ltd. (72) Inventor Tomio Motomura             Matsushita Electric Industrial Co., Ltd.             Sangyo Co., Ltd. (72) Inventor Tatsuo Washizaki             Matsushita Electric Industrial Co., Ltd.             Sangyo Co., Ltd. F term (reference) 4F202 AD03 AD15 AH37 AM33 CA11                       CB01 CB12 CB17 CK00 CK83                 4F206 AD03 AD15 AH37 AM33 JA07                       JB12 JB17 JF05 JF35 JQ06                       JQ81

Claims (1)

Claims: 1. An object to be sealed is sealed in a molded article to be resin-molded by injection molding, and a wire drawn from the object to be sealed is drawn out of the molded article to form a resin. In the resin molding die, the wire is formed of a stranded wire obtained by twisting a plurality of thin wires, and the wire is drawn out of the mold. A resin molding die, wherein a wire passage space having a wire sectional area / space sectional area of 0.3 to 0.5 is formed so as to have a width in the wire passage direction of 5 to 15 mm.