JPH0698646B2 - Molding method for metal plate embedded case - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to molding of a metal plate-embedded case in which a metal plate, at least one surface of which is exposed in a case body made of synthetic resin, is embedded by surrounding the metal plate in the case body. It is about the method.

[Technical background of the invention]

A small electronic device such as a small electronic calculator generally called a calculator is a wiring board or liquid crystal display panel in which electronic parts such as LSI chips are mounted in a device case made of synthetic resin consisting of an upper case and a lower case. It has a structure in which etc. are arranged.

By the way, in this type of small electronic device,
A device is made thinner by providing an opening or a recess corresponding to the position of the thick part of the device built-in part and accommodating part of the thick part in this opening or recess. If an opening or recess is provided in the resin case, the strength of that part will be weakened.Therefore, when providing the opening or recess in the case, make sure that the opening or recess is thin. It is necessary to embed a metal plate around its periphery in the case body and integrally provide it to reinforce this portion.

FIGS. 5, 7, and 9 show a metal plate-embedded case in which a metal plate that reinforces this portion is provided in the opening or recess, and here, the lower case of the electronic device is shown. . The case shown in FIG. 5 is a case body 1 made of synthetic resin.
An opening is formed on the bottom surface of the metal plate, and a metal plate 2 such as a stainless plate is integrally formed on this opening. This case is conventionally formed as follows.

That is, FIG. 4 shows a molding method of the case shown in FIG. 5, and 10a and 10b in the drawing are a pair of molding dies for molding the case body 1, and one of the dies, for example, the case body. 1
A positioning pin 11a for positioning the metal plate 2 is projectingly provided in the mold 10a for molding the inner surface of the mold, and an escape hole 11b for the positioning pin 11a is provided in the other mold 10b. Further, the positioning pin 1 is provided on both the molds 10a and 10b.
Fixing pins 12a and 12b for sandwiching and fixing the metal plate positioned and mounted in the mold by 1a are provided along the peripheral edge of the metal plate 2 so as to face each other. This fixing pin 12a,
Of the 12b, the fixing pins 12a, 12a on the side of one die 10a having the positioning pin 11a are fixed to the die 10a, and the fixing pins 12b, 12b on the side of the other die 10b are in this die 10b. A push spring (not shown) is provided so as to be retractable, and is pressed in a direction projecting into the mold 10b.

This case is formed by mounting the metal plate 2 in the molds 10a and 10b and injecting the molding resin for the case body 1,
A case body 1 in which the periphery of a metal plate 2 is embedded is formed. The metal plate 2 is positioned in the positioning hole 3 (see FIG. 5) of the mold 10a with the molds 10a and 10b open. Pin 11a
Then, the molds 10a and 10b are fitted and positioned in one mold 10a, and when the molds 10a and 10b are closed in this state, the fixing pins 12b and 12b of the other mold 10b pressed by the spring force are attached to the metal plate 2. The metal plate 2 is sandwiched and fixed between the fixing pins 12a and 12a of one of the molds 10a (the fixing pins 12b and 12b press and fix the metal plate 2 as the molds 10a and 10b are closed). 5) If the molding resin of the case body 1 is injected into the molds 10a, 10b with the molds 10a, 10b completely closed, as shown in FIG. The case can be molded. In addition, since the marks a and b of the fixing pins 12a and 12b remain on the case body 1 of the case molded in this way as shown in FIG. The marks b, b of the fixing pins 12b, 12b and the positioning hole 3 of the metal plate 2 are visible. The pin marks b, b and the positioning hole 3 are exterior sheets made of a metal sheet such as aluminum or a resin sheet on the outer surface of the case. It can be obscured by gluing (not shown).

Further, the case shown in FIGS. 7 and 9 is provided with a recessed portion on the inner bottom surface of the synthetic resin case body 1 and the outer surface (the case of FIG. 7) of the thin portion where the recessed portion is formed or A metal plate 2 such as a stainless steel plate is integrally provided by embedding a metal plate 2 such as a stainless steel plate in the case body 1 on the inner surface of the case (case of FIG. 9). The case shown in FIG. 7 is shown in FIG. Molded by such molding dies 10a, 10b, and the case shown in FIG. 9 is the molding dies 10a, 10b as shown in FIG.
It is molded by. The molding dies 10a and 10b shown in FIG. 6 and FIG. 8 are the same as those shown in FIG. 4 except that the mold shape of the portion for molding the recessed portion of the case body 1 is different. Since the case is molded in the same manner as described above, the description thereof will be omitted by giving the same reference numerals to the drawings.

[Problems of background technology]

However, in the above-described conventional method for molding a metal plate embedded case, the metal plate 2 positioned and mounted by the positioning pin 11a in one mold 10a is provided with the positioning pins 12a, 12b provided in both molds 10a, 10b. Since it is clamped and fixed by both, it must be provided on both molds 10a, 10b so as to face each other, which makes the manufacturing of the molds 10a, 10b cumbersome and costly, and also There is also a problem that marks a and b of the fixing pins 12a and 12b remain in the shape of holes in the case body 1 of the molded case.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to simplify the manufacturing of the molding die and to reduce the cost by eliminating the need to provide a fixing pin for fixing the metal plate to the molding die. Along with the down, there is no problem that the fixing pin remains on the case body of the molded case, and the metal plate mounted in one molding die,
A method for forming a metal plate-embedded case that can be firmly fixed so that it does not float or tilt during mold matching or injection of molding resin, and that can form a case in which a metal plate is embedded in a prescribed position in the correct posture. To provide.

[Outline of Invention]

That is, the present invention includes a pair of metal plate attraction magnets, which are embedded and fixed flush with the mold surface in one of the pair of molding dies and attract the side edges of both sides of the metal plate over substantially the entire length thereof, respectively. Positioning pins that project from the mold surface and are fitted into the positioning portions provided on the metal plate are provided, and the metal plate is positioned in the one molding die by fitting the positioning portions to the positioning pins. A metal plate-embedded case is formed by attaching the metal plate to the magnet and fixing the metal plate and injecting a molding resin into the case body in this state. Is.

That is, according to the present invention, the metal plate mounted in the forming die is fixed by the attraction of the magnet instead of using the fixing pin. According to the present invention, the fixing pin for fixing the metal plate to the forming die is used. Since it is not necessary to provide the mold, it is possible to simplify the manufacturing of the molding die and reduce the cost, and it is also possible to eliminate the problem of the conventional molding method that the mark of the fixing pin remains on the case body of the molded case. . Moreover,
According to the present invention, the metal plate is mounted and fixed in one of the molding dies by positioning the positioning portion provided on the metal plate by fitting it into the positioning pin protruding from the mold surface of the molding die. The workability can be easily improved by a very simple work of adsorbing the plate to the magnet.

Further, according to the present invention, the metal plate mounted in the molding die is attracted and fixed by a magnet instead of the fixing pin, but the mounted metal plate is placed near the side edges on both sides of the metal plate. A pair of magnets that attract each other over almost its entire length are fixed without rising or tilting, and lateral displacement is also blocked by the positioning pins, so the position and orientation of the metal plate during mold matching and injection of molding resin There is no change, and a pair of magnets are embedded and fixed in the molding die so that they are flush with the die surface, and these magnets are attracted and fixed near the side edges of both sides of the metal plate over substantially their entire length. Since the side edge of the metal plate is not deformed by the injection pressure of the molding resin, it is possible to mold the case in which the metal plate is embedded in the correct position at the predetermined position. .

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a method for molding a metal plate-embedded case, and FIGS. 2 and 3 show a molded metal plate-embedded case.

First, a molded metal plate burying case will be described. This case is used as a lower case of a small electronic device, and in FIGS. 2 and 3, reference numeral 1 is a case body made of synthetic resin. The case body 1 is provided with a laterally long opening for accommodating a lower portion of a wiring board, a liquid crystal display panel, or the like arranged in a device, on one side of a bottom surface thereof. It is closed by a metal plate 2 which is integrally provided on the. The metal plate 2 is made of a ferromagnetic metal such as iron or nickel, and the metal plate 2 is integrated with the case body 1 by embedding the periphery thereof in the case body 1.
Further, 3 and 3 are positioning holes provided in the exposed portion of the metal plate 2. The positioning holes 3 and 3 are used for positioning and mounting the metal plate 2 in the molding die during molding of the case. The positioning holes 3 and 3 are formed on the back surface of the case body 1 almost entirely. An exterior sheet (not shown) is adhered to the recessed surface 1a formed over it so as to be covered with the metal plate 2.

Next, a method of molding the metal plate-embedded case will be described. In FIGS. 1A and 1B, 10a and 10b are a pair of molding dies for molding the case body 1. A positioning pin that determines the mounting position of the metal plate 2 that is mounted at a predetermined position on the mold 10a that molds the inner surface of the case body 1.
11a is provided so as to project into the mold, and the other mold 10b is provided with an escape hole 11b for the positioning pin 11a. Also,
Numerals 13 and 13 are permanent magnets provided corresponding to the mounting position of the metal plate 2 on one die 10a provided with the positioning pin 11a, and the surfaces of the magnets 13 and 13 are the dies of the die 10a. It is embedded and fixed in the mold 10a so as to be flush with the surface. The magnets 13 and 13 are for adsorbing and fixing the metal plate 2 which is positioned and mounted in the mold 10a by the positioning pins 11a. The magnets 13 and 13 are side edges of the metal plate 2 adsorbed to the magnets 13 and 13. In order to prevent the molding resin from being deformed by the pressure when the molding resin is injected, it is provided at a position where it is attracted as close as possible to the side edge of the metal plate 2, and the magnets 13, 13 are provided on both sides of the metal plate 2. The portions are provided along both sides of the metal plate mounting position along the length direction so as to strongly adsorb the portion over substantially the entire length. The magnets 13, 13 may be horizontally long, or a large number of magnets may be arranged on both sides of the metal plate mounting position along the length direction at appropriate intervals.

As shown in FIG. 1 (a), the molding method of this case is such that the metal plate 2 is inserted into the positioning pin 11a through its positioning hole 3 with the molds 10a and 10b open. And the metal plate 2 is attracted to the magnets 13 and 13 and fixed in the mold 10a. In this state, the molds 10a and 10b are closed as shown in FIG. 1 (b). Molding resin is injected into 10a and 10b to mold the case body 1, whereby the metal plate-embedded case shown in FIGS. 2 and 3 is molded.

Thus, in this molding method, as described above, the metal plate 2 mounted in the molding die is not used for the fixing pin and the metal plate 2 for one die is used.
Since the magnets 13, 13 provided on 10a are fixed by attraction, it is not necessary to provide the molding dies 10a, 10b with fixing pins for fixing the metal plate 2. Therefore, according to this molding method, the manufacturing of the molding dies 10a, 10b can be simplified and the cost can be reduced, and the mark of the fixing pin remains on the case body 1 of the molded case. The problem of the molding method can be eliminated. Moreover, in this molding method, the metal plate 2 is mounted and fixed in one mold 10a by positioning the positioning hole 3 provided in the metal plate 2 in the mold 10a.
The positioning pin 11a protruding from the die surface is used for positioning, and the metal plate 2 can be easily attracted to the magnet by a very simple operation with good workability.

In addition, this molding method uses the metal plate 2 mounted in the mold 10a.
In place of the fixing pins, magnets are attracted and fixed by a magnet. The mounted metal plate 2 has a pair of magnets 13, which attract near the side edges of both sides of the metal plate 2 over substantially the entire length thereof. It is fixed by 13 without rising or tilting, and its lateral displacement is also determined by the positioning pin 11a.
Since it is prevented by the above, there is no displacement of the metal plate 2 and no change in posture at the time of mold matching or injection of molding resin.
Further, a pair of magnets 13 and 13 are embedded and fixed in the die 10a so as to be flush with the die surface, and the magnets 13 and 13 attract and fix near the side edges of both sides of the metal plate 2 over substantially the entire length thereof. Therefore, since the side edge portion of the metal plate 2 is not deformed by the injection pressure of the molding resin, it is possible to mold the case in which the metal plate 2 is embedded at a predetermined position in the correct posture.

In addition, in the above-mentioned embodiment, the molding of the case in which the metal plate 2 is embedded so that both surfaces thereof are exposed has been described. However, in the present invention, one surface of the metal plate 2 as shown in FIG. 6 or FIG. Of course, it can also be applied to the molding of an exposed metal plate embedded case.

〔The invention's effect〕

According to the present invention, the metal plate mounted in the forming die is fixed by the attraction of the magnet instead of using the fixing pin. Therefore, according to the present invention, the fixing pin for fixing the metal plate to the forming die is provided. Therefore, it is not necessary to provide the mold, so that the manufacturing of the molding die can be simplified and the cost can be reduced, and the problem of the conventional molding method that the mark of the fixing pin remains on the case body of the molded case can be eliminated. . Moreover, in the present invention, the mounting and fixing of the metal plate in one of the molding dies is performed by positioning the positioning portion provided on the metal plate by fitting it into the positioning pins protruding from the mold surface of the molding die. It is possible to perform the workability easily with a very simple work of adsorbing the metal plate to the magnet.

Further, according to the present invention, the metal plate mounted in the molding die is attracted and fixed by a magnet instead of the fixing pin, but the mounted metal plate is placed near the side edges on both sides of the metal plate. A pair of magnets that attract each other over almost its entire length are fixed without rising or tilting, and lateral displacement is also blocked by the positioning pins, so the position and orientation of the metal plate during mold matching and injection of molding resin There is no change, and a pair of magnets are embedded and fixed in the molding die so that they are flush with the die surface, and these magnets are attracted and fixed near the side edges of both sides of the metal plate over substantially their entire length. Since the side edge of the metal plate is not deformed by the injection pressure of the molding resin, it is possible to mold the case in which the metal plate is embedded in the correct position at the predetermined position. .

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention in a mold open state and a mold closed state, FIGS. 2 and 3 are perspective views and sectional views of a molded metal plate burying case, FIG. 4 and FIG. 5
FIG. 6, FIG. 6 and FIG. 7, FIG. 8 and FIG. 9 are a cross-sectional view of a conventional molding method in a mold closed state and a cross-sectional view of a molded metal plate embedded case, respectively. 1 ... Case body, 2 ... Metal plate, 3 ... Positioning hole, 10
a, 10b …… Molding die, 11a …… Positioning pin, 13 …… Magnet.

Claims (1)

[Claims] 1. A method for forming a metal plate-embedded case in which a metal plate having at least one exposed surface is embedded in the case body made of synthetic resin, the periphery of the metal plate being embedded in the case body. On the other hand, a pair of metal plate attracting magnets that are embedded and fixed flush with the mold surface and attract near the side edges of both sides of the metal plate over substantially their entire lengths respectively, and a pair of metal plate attracting magnets protruding from the mold surface to the metal plate. A positioning pin to be fitted into the provided positioning portion is provided, and the metal plate is fitted into the molding die of one of the molds by fitting the positioning portion into the positioning pin and positioning the metal plate on the magnet. A method for molding a metal plate-embedded case, comprising adsorbing and fixing, and in this state, the pair of molding dies are combined and a molding resin is injected into the case body.