JPS60244513A - Injection mold for injection molding of double shade for illumination - Google Patents

Abstract

PURPOSE:To improve an appearance shape by preventing the strain generated between a primary shade and a secondary shade, by providing a groove having a specific shape to the injection port of an injection mold for molding a double shade for illumination in such a state that the secondary shade is superposed onto the primary shade. CONSTITUTION:Grooves 12 each having a depth slightly larger than the contraction height of a primary shade at the time of molding and cooling are engraved in the above mentioned primary shade along the lower part and outer periphery thereof. By this structure, the molten synthetic resin, which forms a secondary shade 18, introduced under pressure from a material injection port 17 is forcibly flowed to the lower end and side surface of the primary shade 1 while forcibly presses the lower part of the primary shade 1 to the surface of a male mold 2. Therefore, the synthetic resin forming the secondary shade 18 covering the lower end of the primary shade 1 is prevented from turning around to the inside of the primary shade 1. No strain is generated at the boundary 8 between the primary shade 1 and the secondary shade 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an injection mold for a double shade for lighting in which shades are overlapped and molded.

[Background of the invention]

Conventionally, injection molding molds for double shades, which have a hemispherical or conical shape as shown in Fig. 1 and are formed by overlapping synthetic resin shades of different colors, have been molded by overlapping synthetic resin shades of different colors. In the female mold 8 for secondary molding, which is clamped to the male mold 2 for primary molding to which the primary shade 1 constituting the inner shade is attached, a material injection molding is provided at the top of the part where the secondary shade is to be molded. Press the molten synthetic resin from the inlet 5, and
The void at the lower end of the primary shade caused by the distance 111tA that contracted after cooling 1! A secondary shade was formed to surround J6 and overlap the primary shade 1. When performing secondary molding using the above injection mold, the synthetic resin press-fitted from the gate of the upper part of the secondary shade 1 fills the void 6 along the primary shade 1 to the lower end, and fills the void 6 of the primary shade 1. The lower edge of the mold is pushed apart from the male die 2 and expanded, and as shown in FIG. The problem was that it appeared in a wavy manner.

Further, when a heat radiation hole 9 or the like is provided in the shoulder of the shade, a weld line 10 is formed on the side surface of the shade below the heat radiation hole 9, which has the disadvantage of reducing the commercial value of the molded product. there were. Both of these drawbacks are due to the fact that the material injection port 50 position during secondary molding is provided at the upper edge of the secondary shade, and in the former case, the lower part of the primary shade is directed from the side toward the center during secondary molding. This was caused by a lack of pushing force.

[Purpose of the invention]

The object of the present invention is to obtain an injection molding mold for a double shade for lighting, in which the boundary between the primary shade and the secondary shade is substantially straight, the feld line is not noticeable, and the appearance is excellent.

[Summary of the invention]

The injection mold for a double shade for lighting of the present invention is an injection mold for a double shade for lighting in which a secondary shade is superimposed on a primary shade, and a secondary mold for molding a secondary shade. A material injection port for the mold is provided in the parting part of the female mold and its vicinity, and a groove with a depth slightly larger than the shrinkage height of the primary shade during mold cooling is formed in the parting part of the male mold. By carving along the lower part and its outer circumference, the material press-fitted from the material injection port presses the lower part of the primary shade against the male die, preventing the material from entering the inside of the primary shade. It is something.

[Embodiments of the invention]

Embodiments of the present invention will be described with reference to the drawings. FIG. 4 is a half sectional view showing a state in which the mold is clamped for primary molding in an embodiment of the injection molding mold for a double shade for lighting according to the present invention;
Fig. 5 is a half sectional view showing the clamping state of the secondary molding in the above example, Fig. 6 is an enlarged sectional view of the vicinity of the material injection port in Fig. 5, and Fig. 7 is a side sectional view showing the mold clamping state of secondary molding in the above example. FIG. 2 is a partially cutaway perspective view of the double illumination shade. In Fig. 4, the parting part 11 of the male mold 2 has a depth slightly larger than the shrinking height A (Fig. 2), in consideration of the shrinking height A (Fig. 2) after molding the primary shade and cooling. A groove 12 having a diameter B is provided at the lower part of the primary shade and its outer periphery, and a material inlet 18 for molding is provided at the upper edge portion of the primary shade of the female mold 14. In addition, there is a heat radiation hole 9 provided on the shoulder of the seventh door 15a.
It shows the convex part for. Material injection port 1 of the above mold
Step 3: Press in the molten synthetic resin and open the mold.
As shown in FIG. 5, the lower end of the primary shade 1 contracts to create a gap A between it and the bottom of the male mold 2, and the lower end of the primary shade 1 has a small dimension C as well as the parting part 11. only located below. Next, the mold for secondary molding is clamped, and the secondary molding female mold 16 has a material injection port 17 provided in the parting part 11 and its vicinity, so the material injection port 17 is located at the lower end of the primary shade 1. If it is located slightly above, it becomes K. Therefore, as shown in the enlarged view of FIG.
While strongly pressing the lower part of the molten synthetic resin primary shade 1 press-fitted into the surface of the male mold 2, the synthetic resin covering the lower end of the primary shade is washed away by the lower end and @ surface of the primary shade 1. cannot penetrate inside the primary shade 1, and the boundary 8 between the primary shade 1 and the secondary shade 18 is almost a straight line on the inner surface of the double shade formed as shown in FIG. appears in the form of In addition, when installing the heat dissipation hole 9 in the shoulder of the shade, the material injection port 17 is placed near the lower end of the shade, and the synthetic resin flows from bottom to top along the primary shade 1, so that the weld 2 in 1 is It occurs above the heat dissipation hole 9, and the diameter of the shade becomes smaller as it goes upward, so the Feldline lO becomes smaller than before, but
This position is almost invisible when a lighting fixture with a shade is installed.

〔Effect of the invention〕

As mentioned above, the injection mold for double shade for lighting according to the present invention, the injection mold for double shade for lighting, which is formed by superimposing the secondary shade on the primary shade! In I, the material injection port of the secondary mold for forming the secondary shade is provided in the female mold parting part and its vicinity, and the material injection port of the secondary mold molding mold is provided in the male mold parting part with the shrinkage height when the primary shade is molded and cooled. A slightly larger depth is carved into the lower part of the primary shade and its outer periphery, and the material injection port for the secondary forming is provided at a position slightly above the lower end of the primary shade. The synthetic resin material press-fitted through the material injection port is made to flow while pressing the lower part of the primary shade against the male mold, thereby preventing the material from entering the inside of the primary shade, and thereby improving the lighting secondary of the present invention. The double shade molded using a heavy shade injection mold has a nearly straight boundary between the primary shade and the secondary shade formed on the inner surface of the double shade, and a heat dissipation hole in the shoulder of the shade. The weld line that occurs when the heat dissipation hole is provided appears small above the heat dissipation hole, and a double shade for lighting with an excellent appearance can be obtained.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an example of the appearance of a double shade for lighting;
The figure is a half sectional view showing the clamped state of the conventional mold for molding the secondary shade of the above-mentioned double shade for illumination, FIG. Figure 4 is a half sectional view showing a state in which the mold is clamped for primary molding in an embodiment of the injection molding mold for double shade for lighting according to the present invention, and Figure 5 is a clamping diagram for secondary molding in the above embodiment. FIG. 6 is an enlarged sectional view of the vicinity of the material injection port shown in FIG. 5, and FIG. 7 is a partially cutaway perspective view of the double shade for illumination molded according to the above embodiment. . 1... Primary shade, 2... Male mold, 11... Birch ink part, 12... Groove, 16... Female mold (secondary molding)
, 17... Material υ injection port (secondary molding), 18... Secondary shade. Sell 6 Figure $ 7 Figure

Claims (1)

[Claims] In an injection mold for a double shade for lighting, in which a secondary shade is superimposed on a primary shade, the material injection port of the secondary mold for forming the secondary shade is placed in the parting part of the female mold and its vicinity. A groove with a depth slightly larger than the shrinkage height of the primary shade during molding and cooling is provided in the male parting part.
An injection mold for a double shade for lighting, characterized in that the lower part of the primary shade and the outer circumference thereof are carved.