JPH01128822A - Method for blow-molding body of vehicular lighting fixture - Google Patents

Abstract

PURPOSE:To make it possible to accurately form the inner peripheral surface shape of the body of a lighting fixture and form a plurality of the bodies of the lighting fixtures at the same time by a method wherein body parts of the lighting fixtures, both the backs of which are set to face to each other, are simultaneously formed by means of molds, on each of which the forming surface for forming the inner peripheral surface of the body of the lighting fixture. CONSTITUTION:A parison feeding space is produced between molds 10a and 10b by parting them from each other. Next, a parison 32 is extruded from a feeding port 30. When the length of the parison 32 reaches the predetermined length, the extrusion of the parison is stopped and the parison 32 is pinched by bringing the molds 10a and 10b close to each other. Next, the air is fed from an air pipe 40 in the parison 32 so as to inflate the parison in order to bring the parison 32 into pressingly close contact with the mold forming surfaces 20a and 20b. Under the state as is mentioned above, the molds are cooled down in order to solidify the parison in the molds. After that, by separating the molds 10a and 10b from each other, a formed body W is obtained by taking out of the molds.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a blow molding method for a vehicle lamp body, and particularly to a blow molding method that can simultaneously mold a plurality of lamp body parts by blow molding at -degrees. Regarding.

[Prior art and its problems]

A vehicle lamp is composed of a lamp body with an opening at the front and a lens assembled to the lamp body so as to close the front opening.The lamp body and lens are each made of one piece by injection molding or press molding. They are molded individually.

Further, as disclosed in the prior art of JP-A-58-7325, two case parts 7 are integrally blow-molded with their opening sides facing each other, as shown in FIG. A blow-molded body 6 is made, and this molded body 6 is designated by the symbol Q.
1. A method of manufacturing two flanged cases by cutting at the position shown by Q2 is also known.

However, injection molding and press molding have a problem in that only one lamp body can be manufactured at a time using one mold device, and production efficiency is poor.

In addition, in the case of the above-mentioned method using blow molding, the outside of the case is pressed against the molding surface, so the shape of the inside of the case cannot be molded with high precision. Furthermore, it is also possible to construct a reflective lamp body by constructing the blow-molded body 6 of transparent resin and forming a reflective surface on the outside of the case. However, since the reflective surface is exposed to the outside, it is easily damaged and has poor durability.

The present invention has been made in view of the problems of the prior art,
The purpose is to provide a blow molding method that can mold the inner circumferential shape of a lamp body with high precision and simultaneously mold a plurality of vehicle lamp bodies.

[Means for solving problems]

Next, the present invention will be explained with reference to FIG. 1, which shows an embodiment of an apparatus for carrying out the present invention, and FIGS. 5 and 6, which show molded products formed using the apparatus shown in FIG. explain.

This is a blow molding method in which a parison 32 is pinched between opposing molds 10a and lobs, air is introduced into the parison 32, and the parison 32 is pressed tightly against the molding surfaces of the molds 10a and 10b to form a vehicle lamp body. There, the mold 10a,
10b has a molding surface 20a for molding the inner peripheral surface of the lamp body;
20b is formed, and the lamp body parts Wa and Wb are simultaneously molded with their backs facing each other using the mold 10a and the lob.

[Effect]

The molded body W is molded by one blow molding, and the lamp body portion Wa is molded by the molding surface 20a, and the lamp body portion wb is molded by the molding surface 20b at the same time. In addition, the lamp body portion Wa is tightly pressed against the molding surfaces 20a and 20b.
, Wb are molded, so that a highly accurate body portion inner peripheral surface shape can be obtained.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is an overall configuration diagram of an embodiment of a blow molding apparatus for carrying out the present invention.

In this figure, reference numerals 10a and 10b represent left and right molds that are placed opposite each other, and are moved closer to each other by a drive mechanism (not shown).
Separation operation is possible. The molds 10a and 10b are water molds 12a and '12b, and sewage molds 14a and 14, respectively.
b. The center part consists of small molds 16a and 16b, and each small mold can be separated from each other. Molding surfaces 20a and 20b having the same shape for molding the inner peripheral surface of the lamp body are formed on opposing surfaces of the molds 10a and 10b. The central small molds 16a, 16b are formed with predetermined convex parabolic molding surfaces 26a, 26b for molding the main body of the lamp body.
On the other hand, upper and lower small molds 12a, 12b; 14a, 14
b is a molding surface 22a for molding a peripheral frame portion for lens attachment;
, 22b; 24a, 24b are formed, respectively.

A parison supply port 30 is provided directly above the opposing molds 10a and 10b, and a second
A flat cylindrical parison 32 as shown in the figure is supplied. Further, an air pipe 40 is provided at a position facing the parison supply port 30 so as to protrude upward from the bottom of the mold. And parison supply port 3o
The parison 32 hanging down is pinched by the molds 10a and 10b, air is blown into the parison 32 from the air pipe 40, and the parison 32 is placed on the molding surfaces 20a and 20b.
It is designed to be molded by press-fitting it tightly.

Next, a procedure for blow molding a lamp body using this equipment will be explained.

First, as shown in FIG. 1, a mold 10a is made.

10b is separated to form a parison supply space between the molds 10a and 10b. Next, the parison 32 is extruded from the supply port 30, and when the parison 32 reaches a predetermined length, extrusion of the parison is stopped, and the molds 10a and 10b are brought closer to pinch the parison 32 as shown in FIG. Next, air is supplied into the parison 32 from the air pipe 40 to expand the parison 32, and as shown in FIG. 4, the parison 32 is pressed into close contact with the molding surfaces 2Qa and 2Qb. The mold is then cooled in this state.

Solidify the parison in the mold. After that, the mold 10a,
When 10b is separated and the molded body inside is taken out, a molded body W as shown in FIG. 5 is completed.

The molded body W is formed by integrally molding the lamp body parts Wa and Wb with their backs to each other.
The code shown in the figure is X knee X8. X, -X2 and Y□-Y,
, Y2-Y2, etc., two lamp body parts Wa (Wb) of the same shape are completed. After that, the lamp body is completed by removing burrs, drilling a bulb socket mounting hole, or forming a reflective film on the inside of the lamp body.

In this way, in the blow molding method using the apparatus of this embodiment,
Since two lamp bodies can be obtained from the molded body W formed by the -degree molding, production efficiency can be increased accordingly.

In addition, since the inner circumferential surface of the body portion W a ('W b ) of the molded object W is pressed into close contact with the mold forming surfaces 20a and 20b, the inner circumferential surface of the body portion Wa (Wb) has a high precision. By forming a reflective surface thereon by aluminum vapor deposition, painting, etc., it is possible to create a highly durable reflective lamp body with the reflective surface formed inside the body.

Additionally, the amount of air supplied into the parison during blow molding can be reduced compared to conventional blow molding methods due to the smaller volume of the cavity, which can shorten the blow molding process and improve blind work efficiency.

In addition, in the above embodiment, the molding surfaces 20 of the molds 10a and 10b
a, 20b The bowl-shaped lamp body is molded as a bowl-shaped mold, but the molding surface may be rectangular to mold a rectangular lamp body. Rectangular lamp body part W as shown in Figure 7
A molded body W1 consisting of a' and Wb' is obtained.

FIG. 8 shows another embodiment of the blow molding apparatus for carrying out the present invention, and shows a cross-sectional view of the main part of the mold apparatus.

The mold apparatus is composed of two sets of opposing molds 10c, 10d, 10e, and 10f that can move toward and away from each other. Opposing surfaces of the molds 10c, 10d, 10e, and 10f each have a molding surface 20 for molding the inner peripheral surface of the lamp body.
c, 20d, 20e.

2Of is formed, and four lamp body parts W are formed at the same time.
It is possible to mold c, Wd, We, and Wf.

FIG. 9 shows a blow-molded body formed according to this embodiment, and this molded body W2 has four lamp body parts W.
c, Wd, We, and Wf are formed, and four lamp bodies can be obtained by cutting at predetermined positions and separating them from each other.

In the above embodiments, the case where two lamp body parts (the embodiment shown in FIG. 1) or four lamp body parts (the second embodiment) are molded at the same time has been described, but the present invention is not limited to this. No, there are 3 in the mold.

By forming a plurality of molding surfaces for molding a plurality of lamp body parts, such as five or six, an appropriate number of lamp body parts can be molded at the same time.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a plurality of lamp body parts can be simultaneously molded by one blow molding process, so that the production efficiency of lamp bodies is improved. Further, since the lamp body manufactured according to the present invention can form a highly accurate reflective surface on the inside, it can be used as a reflective lamp body with excellent durability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a blow molding apparatus for carrying out the method according to the present invention, FIG. 2 is a sectional view taken along the line ■-n shown in FIG. 1, and FIGS. FIG. 5 is a perspective view of a molded body obtained by the method according to the present invention, and FIG. 6 is a longitudinal sectional view of the molded body shown in FIG. 5. FIG. 7 is a perspective view of a molded article of another shape obtained by the method according to the present invention, and FIG. 8 is a cross-sectional view of a main part of another embodiment of a blow molding apparatus for carrying out the method according to the present invention. , FIG. 9 is a perspective view of a molded article of still another shape obtained by the method according to the present invention. FIG. 10 is a perspective view of a molded article obtained by a conventional blow molding method. 10a, 10b, loc, 10d+ 10e, 10f・
・・Mold, 20a, 20b, 20c, 20d, 20e, 2Of・・
- Molding surface, 32... parison. 4o...Air pipe, W, W work, W2... Molded body, Wa, Wb, Wa', Wb', Wc, Wd, We. Wf...Lamp body part. Figure 1 Figure 2 Figure 6 Figure Y2 Figure 7 Figure 9 Figure 10

Claims (1)

[Claims] (1) A blow molding method for a vehicle lamp body, in which a parison is pinched between opposing molds, air is introduced into the parison, and the parison is pressed into close contact with the molding surface. A blow molding method for a vehicle lamp body, characterized in that a molding surface for molding the inner peripheral surface of the lamp body is formed, and a plurality of lamp body parts with their backs facing each other are simultaneously molded.