JPH05337983A - Method for molding composite lens for lamp device of vehicle - Google Patents

Abstract

PURPOSE:To eliminate the sink of a lens by a method wherein a dark color resin is previously injected to be molded and a light color resin is injected under high pressure when the dark color resin is in a semi-cured state to be allowed to penetrate into the low density part of the dark color resin. CONSTITUTION:A mold 20 is constituted so that a yellow mold part 21 and a red mold part 22 are slid at a specified position. At first, a red resin 11 is injected in the red mold part 22 to be molded into a lens part 2 for a taillight. When the red resin 11 becomes a semi-cured state, the mold 21 is slid and a yellow resin 12 is injected into the mold 21 under pressure higher than the injection pressure of the red resin 11. As a result, the yellow resin 12 penetrates into the central low density part of the red resin 11 in a semi-cured state to prevent the generation of a sink in the lens part 2 for the taillight. Since the yellow resin 12 penetrates in the central part delayed in curing of the red resin, the resin 12 is not exposed to the surface of the lens part 2 for the taillight and the lens part 2 for the taillight is kept red and a lens 3 for a direction indicator is kept yellow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle lamp lens, and more particularly, to molding a compound lens in which a yellow direction indicator lens and a red tail lamp lens are integrally formed. It relates to the method.

[0002]

2. Description of the Related Art A conventional method for molding a compound lens 90 of this kind is based on a direction indicator lens portion 91 and a tail lamp lens portion 92.
FIGS. 5 and 6 show an example in which and are integrated, and the mold 20 for forming the compound lens 90 is a yellow mold part 21 for forming the direction indicator lens part 91. And the red mold part 22 for forming the tail lamp lens part 92 are slid, and first, in the state of FIG. 5 in which a step is provided between the yellow mold part 21 and the red mold part 22. Either one, for example, the yellow resin 12 to the yellow mold part 21
Is injected by a two-color molding machine.

After that, after waiting for the injected yellow resin 12 to harden, both mold parts 21 and 22 are slid to the position where the final shape of the compound lens 90 is obtained, as shown in FIG.
On the other hand, in this case, the red resin 1 is applied to the red mold part 22.
1 is performed, and at this time, the yellow mold part 21 has already been filled with the yellow resin 12, so that the red resin 11 does not enter the yellow mold part 21 side, and FIG. As shown in FIG. 7, the compound lens 90 in which the direction indicator lens portion 91 and the tail lamp lens portion 92 are closely attached and integrated is obtained.

[0004]

However, in a lens formed by this type of injection molding, when a thick portion 90a is provided on the peripheral edge as shown in FIG. 8 due to design requirements, a so-called sink mark is formed. This causes a problem that H is generated and impairs the appearance. Especially, in the compound lens 90 in which this type of two-color molding is performed, a darker portion such as red is more noticeable than yellow. The external appearance is further impaired, and it has been a problem to solve this point.

[0005]

As a concrete means for solving the above-mentioned conventional problems, the present invention is a vehicle for molding lens parts of different colors closely adjoining each other by a two-color molding machine as an integrated compound lens. In a method of molding a compound lens for a lighting fixture, a dark color side resin is first injected and molded, and the dark color side resin is semi-cured in a mold and the dark color side resin is injected. By providing a method for molding a compound lens for a vehicle lighting device, which is characterized by injecting a resin on the light color side at a higher pressure than the above, it is possible to reduce sink marks particularly generated in a dark color portion, thereby reducing It solves the problem.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail based on an embodiment shown in the drawings. In order to facilitate understanding, the same parts as those in the conventional example will be described with the same reference numerals. A reference numeral 20 in FIG. 1 is a mold, and the mold 20 has a structure in which a yellow mold portion 21 and a red mold portion 22 are slid at predetermined positions. The shape of the compound lens 1 obtained by the method is basically the same as that of the conventional example.

However, according to the present invention, the injection of the resin by the two-color molding machine (not shown) is first performed from the dark side, and therefore, in this embodiment, the red mold portion 22 is first injected. The red resin 11 is injected to mold the tail lamp lens unit 2.

Further, in the present invention, in the semi-cured state in which the above-mentioned resin on the dark side, that is, the red resin 11 is not completely cured, the slide on the die 20 shown in FIG. The resin, that is, the yellow resin 12 is injected to mold the direction indicator lens portion 3, and the injection pressure of the yellow resin 12 at this time is higher than the injection pressure when the red resin 11 is injected. Is set as.

Next, the operation and effect of the above molding method will be explained. By injecting the yellow resin 12 while the red resin 11 is semi-cured, the red resin 1
1 starts to harden by cooling and starts to decrease in volume, and when the density of the portion which is still in the molten state is decreasing, the yellow resin 1
2 is performed at a high pressure, the yellow resin 12 penetrates into the density-reduced portion of the red resin 11 as shown in FIG. 3, and the red resin 11, that is, the darker taillight lens portion 2
The occurrence of sink marks in is almost completely prevented.

At this time, since the curing of the red resin 11 is started from the surface portion in contact with the red mold portion 22, the yellow resin 12 injected later is the most cured as shown in FIG. Will enter the central portion of the thick portion 11a, which is delayed, and will never be exposed on the surface of the tail lamp lens portion 2.

At the same time, the yellow resin 12 that has entered the inside of the red resin 11 is masked by the surrounding red resin 11 due to the difference in color density, and therefore, it has entered. Is not detected from the outer surface of the compound lens 1 at all. Incidentally, on the side of the yellow resin 12, the degree of occurrence of sink marks can be reduced by increasing the injection pressure by the present invention as compared with the conventional case.

[0012]

As described above, according to the present invention, when a compound lens is molded by using a two-color molding machine, the resin on the dark color side is first injected and molded, and the resin on the dark color side is molded. Is a semi-cured state in the mold, the dark side resin is injected at a higher pressure than the light side resin is injected. The resin on the light color side is allowed to enter the area where the density is reduced due to the shrinkage of the resin on the side, and the sink marks that occur on the dark color lens, which is particularly conspicuous, are eliminated to improve the appearance of this type of complex lens. It has an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a first step of an embodiment of a method for molding a compound lens for a vehicle lighting device according to the present invention.

FIG. 2 is a schematic sectional view showing a subsequent step of the same example.

FIG. 3 is a front view showing a compound lens obtained by a molding method according to the present invention.

4 is a sectional view taken along the line AA of FIG.

FIG. 5 is a schematic sectional view showing a first step of a conventional method for molding a compound lens.

FIG. 6 is a schematic cross-sectional view showing a subsequent process of the same conventional example.

FIG. 7 is a front view showing a compound lens obtained by a conventional molding method.

8 is a cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

 1 ... Composite lens 2 ... Taillight lens part 3 ... Direction light lens part 11 ... Red resin 11a ... Thick part 12 ... Yellow resin 20 ... Mold 21 ... Yellow mold part 22 ...... Red mold part

Claims (1)

[Claims] 1. A molding method of a compound lens for a vehicle lamp, wherein lens parts of different colors that are in close contact with each other are molded by a two-color molding machine as an integrated compound lens. A vehicle lamp characterized by being molded and injecting the light-colored resin at a pressure higher than that when the dark-colored resin is semi-cured in the mold. For molding compound lenses for automobiles.