JPH10159981A - Sealing structure for complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure for a plastic complex, which helps to automate the manufacturing processes of a plastic complex to the utmost and hold sufficient sealing performance of the sealed part of the plastic complex. SOLUTION: A sealing structure is provided for a pair of molds 1a and 1b. One mold 1a is formed at its flange 2a on its one plane with a recessed groove 3, and the other mold 1b is formed at its flange 2b with a projection 4. The projection is pressed into the recessed groove to effect the sealing structure. A liquid sealant which has fluidity prior to its hardening and has elastic solidity after its hardening is placed into the recessed groove 3 of the mold 1a arranged horizontally, and is then hardened. The mold 1a provided with an elastic sealant layer 5 thus obtained and the mold 1b are thereafter tightly pressed on each other such that the projection 4 is embedded in the elastic sealant layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure for electronic equipment which requires waterproofing, such as wireless communication equipment.

[0002]

2. Description of the Related Art Conventionally, as a seal structure of a device requiring waterproof such as a wireless communication device, as shown in FIGS. 5 and 6, a liquid sealant (Y) is first applied to a molded body having a flange portion. After application coating and curing, another molded body was assembled to form a seal portion. (Note that as the liquid sealant used here, a moisture-curable silicone resin having high viscosity and high thixotropy is often used.) Another method is disclosed in Japanese Utility Model Laid-Open No. 1-97597. Then, a string-like material having elasticity is buried in a concave groove provided in the molded body, and another molded body having a convex body is assembled to this, thereby forming a seal portion.

[0003]

However, in the former method described in the prior art, since the elastic sealing material layer (after curing) must be provided in a shape protruding from the flange surface, the liquid sealing agent has a high viscosity. Or high thixotropy was required. However, such a high-viscosity, high-thixotropic liquid sealant tends to have a non-uniform shape when applied to the flange portion in a beat shape.
Therefore, since the thickness and width of the elastic sealing material layer after curing are unstable depending on the location, even if the sealing portion is formed in combination with another molded body, a gap is easily formed, and a sealing failure is likely to occur. There were drawbacks.

[0004] In the latter method, it is not only time-consuming to insert a separately manufactured cord-shaped elastic body into the groove of the seal portion provided on the molded body, but also the cord-shaped elastic body is required. Since the product itself is easily damaged, care must be taken in storage and handling, which has led to an increase in the cost of the product. Accordingly, it is an object of the present invention to provide a composite product sealing structure in which the production process can be automated as much as possible when producing a composite, and the sealing property of the sealing portion can be sufficiently maintained.

[0005]

A pair of molded bodies (1a, 1a) are provided.
b), a flange (2a) formed on one plane of one molded body (1a) has a concave groove (3), and a flange (2b) of the other molded body (1b) has a groove (3). In the seal structure in which the convex body (4) is provided and is formed by pressing the convex body so as to be buried in the concave groove, it shows fluidity when not cured and becomes a solid elastic body after curing. The liquid sealing agent is filled with a concave groove (3) of the molded body (1a) arranged horizontally.
The molded body (1a) and the molded body (1b) having the elastic sealing material layer (5) formed by being filled and cured are pressed tightly so that the convex body (4) is buried in the elastic sealing material layer (5). The above problem was solved by forming a composite seal structure.

[0006]

The liquid sealant which exhibits fluidity when not cured and becomes a solid elastic body after curing is used, so that the sealant easily flows according to the shape of the groove provided in the flange portion of the molded body. Therefore, the elastic sealing material after curing can also impart smoothness to its surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show the steps of manufacturing a plastic composite product sealing structure according to the present invention. Although a plastic molded product (polyamide injection molded product) is used in this embodiment, a metal molded product such as aluminum die cast may be used.

FIG. 1 shows a plastic composite used for a body of a small communication device such as a mobile phone. This plastic composite is composed of two plastic molded bodies (1a, 1).
b), and a flange portion (2a, 2b) is formed at a joint portion between the two. A concave groove (3) for forming an elastic sealing material layer is formed in one of the flange portions (2a), and the other flange portion (2b).
Is provided with a convex body (4) corresponding to the concave groove (3). Further, the concave groove (3) is provided with an elastic sealing material layer (5) obtained by curing a liquid sealing agent. Then, two plastic moldings (1a, 2
b) a concave groove (3) provided in each flange portion
And the convex body (4) are engaged with each other, that is, in a state where the convex body (4) presses and deforms the elastic sealing material layer (5) formed in the concave groove, a screw (not shown) or the like is used. Is fixedly joined.

Next, a method of manufacturing the elastic sealing material layer (5) formed in the groove will be described. FIG. 2 is a view showing a state in which the concave groove (3) is filled with the liquid sealant (X). First, in the step of filling the groove with the liquid sealant, the flange surface of the molded body having the groove formed therein is fixed horizontally, and then the liquid sealant is grooved from the nozzle (A) using an automatic coating machine or the like. To perform filling. At this time, if the viscosity of the liquid sealant or the shape of the groove is insufficient to wrap the liquid sealant into the groove, or if the liquid sealant is filled to remove air or the like entrained at the time of filling, Vibration may be applied to the body to assist the flow of the liquid sealant or remove bubbles. As a result, the smoothness of the surface of the elastic sealing material layer can be further improved, and cracks and missing portions can be eliminated. The filling amount of the liquid sealant depends on the shape of the convex body (4) of the other molded body to be combined.
If the convex body is large, the filling amount of the liquid sealing agent is small, and if the convex body is small, the filling amount is large and is arbitrarily determined depending on the kind of the liquid sealing agent used, the elasticity of the cured product, the shape of the groove, and the like. Further, the shape of the concave groove formed in the flange portion may be formed so that the bottom portion is formed wider than the opening portion to prevent the elastic sealing material from falling off.

The liquid sealant used here has a viscosity of 50 Pa · s in a liquid state at normal temperature.
Hereinafter, any material having a thixotropy index of 2.0 or less, which forms an elastic sealing material layer after curing, may be used. In addition, for example, a silicone resin, an acrylic resin, a urethane resin, or the like can be arbitrarily selected and used depending on the material of the molded body or the shape of the concave groove. In addition, these liquid sealants can be cured by various methods depending on the combination with the curing agent. Specifically, curing by moisture in the air,
Although curing by irradiation with light such as ultraviolet light is possible, it is preferable to use a photocurable resin in consideration of mass productivity.
In this example, a moisture-curable silicone resin provided with photocurability (the property before curing is a viscosity of 10 Pa at room temperature).
S) A thixotropic index of 1.5) was used.

Next, FIG. 3 will be described. The liquid sealing agent filled in the concave groove in the above-described filling step is irradiated with ultraviolet rays (B) of about 3000 mJ / cm ² using an ultraviolet irradiation lamp (not shown) to cure the liquid sealing agent and form the elastic sealing material layer. Formed. The surface of the cured elastic sealing material layer was extremely smooth, and was well adapted to the concave grooves and completely cured and adhered. In addition, since this liquid sealing agent cures even in the presence of moisture, it can be cured with the passage of time to form a complete elastic sealing material layer (5) even in a concave groove having a shape that is hardly irradiated with ultraviolet rays. A composite was produced by combining the plastic molded article (1a) and the plastic molded article (1b) thus obtained, and the sealing property between both molded articles was extremely good. Also, it was found that even if both were once separated and reconnected, the sealing properties were good, and repeated use was possible.

Next, FIG. 4 shows another embodiment of the present invention. According to this, a concave groove (6a, 6b) and a convex body (7a, 7b) are formed in each flange portion of a pair of plastic molded bodies (9a, 9b) constituting a plastic composite.
Are formed, and elastic sealing material layers (8a, 8b) formed by hardening a liquid sealing agent are provided in respective concave grooves formed in the flange portion. Further, the shape of the convex body and the shape of the concave groove are not particularly limited. For example, the convex body is preferably a mountain-shaped one having a cross-sectional shape and a smooth head, and the shape of the concave groove is a semicircle. It may be a columnar groove.

[0013]

According to the present invention, since the surface of the cured sealing material layer has a higher smoothness than that of the liquid sealing agent having high viscosity and high thixotropy, the sealing portion is formed by combining with another molded body. High sealing performance when done. In addition, since the elastic sealing material layer is formed so as to be buried in the concave groove of the flange portion, the elastic sealing material layer is not easily damaged even if the attachment and detachment with another molded body are repeated.

When a separately formed string-like elastic sealing material layer is used, the elastic sealing material is soft and easily damaged, so that it is difficult to automatically assemble the flange portion with a machine. On the other hand, when the method of the present invention is used, the above-described manual work is not required, so that the work efficiency is high and mass productivity is good. Furthermore, when using another formed string-shaped elastic sealing material, the shape of the elastic sealing material is formed to be slightly larger than that of the flange portion so as to match the groove shape of the flange portion. The workability becomes extremely poor if the close-fixing property is secured. Therefore, in order to improve the workability, if the shape is slightly smaller than the shape of the concave groove to increase the work efficiency, the elastic sealing material may fall off. On the other hand, in the present invention, since the sealing material layer is formed according to the shape of the concave groove, sufficient sealing performance can be exhibited even with a thinner shape. Therefore, the width of the groove forming the sealing material layer can be reduced, which is useful for reducing the size and weight of the molded body.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an application of the present invention to a communication device.

FIG. 2 is a partial cross-sectional view showing a manufacturing process of the present invention.

FIG. 3 is a partial cross-sectional view showing a manufacturing process of the present invention.

FIG. 4 is a partial cross-sectional view showing another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a manufacturing process of a conventional example.

FIG. 6 is a partial cross-sectional view showing a manufacturing process of a conventional example.

FIG. 7 is a partial sectional view showing a conventional example.

[Explanation of symbols]

 Reference Signs List A Nozzle for applying liquid sealing agent B Ultraviolet X Liquid sealing agent having fluidity Y Conventional high-viscosity, high-thixotropic sealing agent 3 Concave groove 4 Convex body 5 Elastic sealing material layer 10 String-shaped molding Elastic sealing material

Claims (4)

[Claims] 1. A flange portion (2a) formed on one plane of one molded body (1a) of a pair of molded bodies (1a, 1b).
Has a concave groove (3), and a flange (2b) of the other molded body (1b) is provided with a convex body (4) so as to substantially coincide with the concave groove (3). In the sealing structure configured by pressing the convex body so as to be buried in the concave groove, a liquid sealing agent which exhibits fluidity when not cured and becomes a solid elastic body after curing is horizontally disposed. The molded body (1
The molded body (1a) and the molded body (1b) in which the elastic sealing material layer (5) is formed by injecting and filling into the concave groove (3) with a smaller amount than the volume of the concave groove and hardened to form the convex body. A composite sealing structure in which (4) is pressed tightly so as to be buried in the elastic sealing material layer (5). 2. The liquid sealant has a viscosity of 50 at room temperature.
The seal structure for a composite according to claim 1, wherein the thixotropy index is 2.0 or less and Pa / s or less. 3. The seal structure according to claim 1, wherein the cross-sectional shape of the convex body (4) formed on the molded body (1b) is a mountain shape with a smooth head. 4. The sealing structure for a plastic composite according to claim 1, wherein the liquid sealant contains a metal filler.