JPH1076534A - Resin molded part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve electrical and mechanical properties by forming a contact part between a molded resin and a spacer into such a structure that not crack and peel are generated. SOLUTION: In a resin molded part containing a metal part of an electric or an electronic part as a built-in product 1, a spacer 5 for holding the built-in product 1 at a specified position in a molded resin 2 covering the external part of the built-in product 1 has a jutted-out upper end part coming into contact with the outer surface of the molded resin 2. Consequently, when the molded resin 2 shrinks due to its curing process after injection into a mold, the part, which comes into contact with the spacer 5, of the molded resin 2 undergoes the curing/shrinking process in such a way that the part presses the spacer inwardly, as the upper end part 53 of the spacer 5 is jutted out to form an inclination. Thus both molded resin 2 and spacer 5 become tightly integrated and also the internal stress of the end part of the spacer 5 is moderated so that a crack or a peel hardly occurs in the molded resin 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to metal parts and electric / electronic devices.
The present invention relates to a resin molded component having an electronic component as a built-in component.

[0002]

2. Description of the Related Art Conventionally, resin-molded parts having built-in metal parts and electric / electronic parts are as shown in FIGS. This conventional resin molded part is a ground propulsion coil for a magnetic levitation railway, and has a structure in which a coiled conductor 1 is wound around a coiled conductor 1 with a casting resin 2. When manufacturing such a resin molded part, in order to hold the conductor 1 at a predetermined position in the molding resin 2 without bias, as shown in FIGS. In such a position, a spacer 4 (having a columnar shape shown in FIG. 9) is set on the mold 3 and the molding resin 2 is cast. As a result, the completed resin molded component has a structure in which spacers 4 are scattered in the mold resin 2 over the entire length of the conductor 1 as shown in FIG.

[0003]

However, in such a conventional resin molded part, internal stress generated due to curing shrinkage of the poured molding resin concentrates on a contact portion with the spacer, and cracks and cracks are formed on this portion. Peeling is apt to occur, and there is a problem that the cracks and peeling allow moisture and other substances to penetrate into the built-in components and induce electrical damage or mechanical damage.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and by devising the shape of the spacer, the internal stress generated at the end of the spacer is alleviated. It is an object of the present invention to provide a resin molded part which is free from cracking and peeling, and thus has excellent electrical and mechanical properties.

[0005]

According to a first aspect of the present invention, there is provided a resin molded component having a metal component or an electric / electronic component as a built-in component, wherein the built-in component is held at a predetermined position of a mold resin covering the outside thereof. In this case, the end of the spacer in contact with the outer surface of the molding resin has a protruding shape.

In the resin molded part according to the first aspect of the present invention, at the time of curing shrinkage after casting of the molding resin, the end portion of the spacer is projected and inclined, so that the contact portion of the molding resin forms the spacer. It is hardened and shrunk in the form of being pressed inward, so that both are well integrated.Also, the internal stress at the end of the spacer is relaxed, so that cracks and peeling do not occur in the mold resin, and it has excellent electrical and mechanical properties. Become.

According to a second aspect of the present invention, in the resin molded component of the first aspect, the surface of the end portion having the protruding shape of the spacer is roughened, whereby the contact area between the mold resin and the spacer is increased. To further improve the integration of the two.

According to a third aspect of the present invention, in the resin molded part according to the first or second aspect, the inclination angle of the protruding end of the spacer is set to 15 to 30 °. By setting the angle, the internal stress of the contact portion of the mold resin with the spacer is effectively relaxed, and the occurrence of cracks and peeling of the mold resin is more effectively suppressed,
It has better electrical and mechanical properties.

According to a fourth aspect of the present invention, there is provided the resin molded component according to the first to third aspects, wherein a step is provided in the inclined portion of the end portion which has a protruding shape of the spacer, whereby the spacer of the mold resin is formed. The internal stress of the contact portion is divided and relieved by a step, and cracks and peeling are more effectively prevented.

According to a fifth aspect of the present invention, there is provided the resin molded component according to any of the first to third aspects, wherein a concave groove is provided in the inclined portion of the end portion which has a protruding shape of the spacer, whereby the spacer of the mold resin is provided. The internal stress of the contact portion with the substrate is divided and relieved by the concave groove, so that cracks and peeling are more effectively prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. The first embodiment of the present invention shown in FIG. 1 is a resin molded part of a ground propulsion coil of a magnetic levitation railway similar to the conventional example, and the bottom of the spacer 5 has a bowl shape as shown in FIG. The middle body portion 52 is greatly bulged, and the upper half portion 53 is a frusto-conical projection shape inclining at an inclination angle of 15 to 30 °, and the height from the bottom surface to the upper bottom surface is required for the molding resin 2 to be cast. Thickness.
Here, it is set to about 13 mm. Spacer 5
Is made of a material which is familiar with the mold resin 2 and is the same as or close to the mold resin.

The molding resin 2 is a thermosetting resin containing a liquid bisphenol-based epoxy resin as a main component and further containing a curing agent and a filler.

When resin-molding the built-in component 1 such as a metal component or an electric / electronic component, a spacer 5 is provided at an appropriate place in the mold 3 as shown in FIGS.
One side is in contact with the built-in component 1 and the upper half 53 is arranged to face outward, and the molding resin 2 is cast and cured.

The molding resin 2 slightly shrinks when it is hardened, but due to the protruding shape of the upper half 53 of the spacer 5, the molding resin 2 moves the spacer 5 toward the built-in component 1 at the contact portion between the molding resin 2 and the spacer 5. In the case of the spacer 5, the bottom 51 is also bowl-shaped, so that the mold resin 2 holds the spacer 5, and the integration of the interface between the two is strengthened.

The internal stress of the mold resin 2 remaining at the interface is also greatly reduced as shown in Table 1 and FIG.

[0016]

[Table 1] Table 1 and FIG. 4 show that the upper half 5
3 has a conventional vertical (90 °) tilt angle, a tilt angle of 30 ° and 15 ° as an embodiment of the present invention, and a comparative example having a steeper tilt angle than these. This is a result of a simulation analysis of the residual stress of the resin mold component obtained under the same manufacturing conditions. It can be seen that in the case of the present invention, the stress is reduced to about 2/3 as compared with the conventional product. Also, in the case of the comparative example, the internal stress is smaller than that of the conventional example, indicating excellent characteristics.
In particular, when the inclination angle is set to 30 to 15 °, the internal stress becomes smaller than in the case of the comparative examples of other inclination angles. Therefore, in practice, it is preferable to set the angle in this range.

As a result, the spacer 5 and the molding resin 2 are well integrated, and the residual stress of the molding resin 2 is small, so that the molding resin 2 is not easily cracked or peeled off. Therefore, the electrical insulation characteristics and mechanical strength are not easily reduced, and the various characteristics can be greatly improved as compared with the conventional parts.

In the first embodiment, the surface of the spacer 5 is roughened by matte finish to increase the contact area with the mold resin 2 to further improve the integration of the two. Thus, various characteristics such as electrical insulation characteristics and mechanical strength of the resin molded component can be improved.

Although the bottom portion 51 of the spacer 5 in the above embodiment has a bowl shape, this portion may be the same as that of the conventional example. However, when this portion is formed in a bowl shape as in the embodiment, integration with the mold resin 2 becomes stronger.

Next, a second embodiment of the present invention will be described with reference to FIG. The feature of the second embodiment resides in that the shape of the spacer is changed. That is, as shown in FIG. 5, a step 54 is provided in the upper half portion 53 'of the spacer 5' to form a two-step structure, and the inclination angle of each step is set to 15 to 30 degrees as in the first embodiment. I have.

As a result, when the resin molded part is manufactured as shown in FIG. 1, the internal stress can be divided at the step 54 to more effectively reduce the internal stress.
As a result, cracks and peeling are less likely to occur in the mold resin 2, and various characteristics can be further improved.

Next, a third embodiment of the present invention will be described with reference to FIG. The feature of the third embodiment is also in the shape of the spacer. As shown in FIG. 6, a concave groove 55 is formed on the inclined surface of the upper half 53 "of the spacer 5" over the entire circumference. Thereby, when the resin molded part is manufactured as shown in FIG. 1, the internal stress can be divided by the concave groove 55, and the internal stress can be more effectively relieved. And various characteristics can be further improved.

In the spacers 5 'and 5 "of the second and third embodiments, the entire surface is matte-finished to obtain a rough surface, so that the contact area with the mold resin 2 is further increased. It is possible to further improve the integration of the two by widening, and to further improve various properties such as electrical insulation properties and mechanical strength as a resin molded part.

Further, the spacers 5 ', 5'
The bottom portion 51 of 5 ″ is bowl-shaped, but this portion may be the same as the conventional example. Further, in these first to third embodiments, the resin molded part of the ground propulsion coil of the magnetic levitation railway is used. However, the present invention is not limited to this, and can be widely applied to general resin mold parts.

[0025]

As described above, according to the first aspect of the present invention,
Because the end of the spacer has a protruding shape and is inclined,
When the mold resin cures and shrinks after casting, the contact portion of the mold resin shrinks and cures in a manner that presses the spacer inward, and the two are well integrated.Also, the internal stress at the end of the spacer is relaxed and cracks and It is excellent in electrical and mechanical properties without peeling.

According to the second aspect of the present invention, the surface of the protruding end portion of the spacer is roughened, so that the contact portion between the mold resin and the spacer can be more easily adapted. Can be further improved.

According to the third aspect of the present invention, the internal stress at the contact portion of the mold resin with the spacer is significantly reduced by setting the inclination angle of the protruding end of the spacer to 15 to 30 °. As a result, the occurrence of cracks and peeling of the mold resin can be effectively suppressed, and electrical and mechanical properties can be improved.

According to the fourth aspect of the present invention, a step is provided in the inclined portion of the protruding end portion of the spacer, whereby the internal stress of the contact portion of the mold resin with the spacer is divided by the step and reduced. The generation of cracks and peeling can be more effectively prevented.

According to the fifth aspect of the present invention, the recessed groove is provided at the inclined portion of the end of the spacer having the protruding shape, so that the internal stress of the contact portion of the mold resin with the spacer is divided and relieved by the recessed groove. However, the occurrence of cracks and peeling can be more effectively prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a perspective view of a spacer used in the embodiment.

FIG. 4 is a graph showing a change in residual internal stress of a mold resin depending on a tilt angle of a spacer in the embodiment.

FIG. 5 is a front view of a spacer used in a second embodiment of the present invention.

FIG. 6 is a front view of a spacer used in a third embodiment of the present invention.

FIG. 7 is a partially cutaway front view of a conventional example.

FIG. 8 is an enlarged view of a portion B in FIG. 7;

FIG. 9 is a perspective view of a spacer used in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Built-in thing 2 Mold resin 3 Die 5, 5 ', 5 "Spacer 51 Bottom 52 Body 53, 53', 53" Upper half 54 Step 55 Groove

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroki Sekiya 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant, Inc.

Claims (5)

[Claims] 1. A resin molded part having a metal part or an electric / electronic part as a built-in part, wherein a part for holding the built-in part at a predetermined place of a mold resin covering the outside thereof is provided outside the mold resin. A resin molded part characterized in that an end in contact with the surface has a protruding shape. 2. The resin molded part according to claim 1, wherein a surface of the end portion of the spacer having a protruding shape is roughened. 3. The resin molded part according to claim 1, wherein an angle of inclination of the protruding end of the spacer is 15 to 30 °. 4. A step is provided at an inclined portion of said end portion having a projecting shape of said spacer.
The resin molded part according to any one of the above. 5. A groove is provided at an inclined portion of said end portion having a protruding shape of said spacer.
The resin molded part according to any one of the above.