JPH0471102A - Protector molding method of lighting fixture for vehicle - Google Patents

Abstract

PURPOSE:To prevent the change of luster generated when a protector is touched with fingers by applying horning machining on the inner face of a cavity to be injected and molded with a protector material to form numerous fine irregularities. CONSTITUTION:A lamp housing 1 is pinched and inserted between a die (A) 12 and a die (B) 13. A cavity 12a is provided on the outer periphery of the flange section 1b of the lamp housing 1 on the die (A) 12, and fine irregularities are formed on the inner periphery by horning machining. Abrasive grains with the grain size 60-80 are sprayed by compressed air to apply horning machining, for example. When a thermoplastic elastomer 11 is injected into the cavity 12a and solidified and extracted from the dies 12, 13, a protector 14 with fine irregularities on the surface is formed. The protector 14 has fine irregularities and is frosted, and no change of luster is generated when it is touched with fingers.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for molding a protector for a vehicle lamp, and more specifically, a flexible rubber elastic The present invention relates to a method for molding a protector for a vehicle lamp having a structure in which the protector is integrally molded from a material having the following properties.

[Conventional technology]

In a vehicle lamp that comes into contact with a vehicle body panel, such as a rear combination lamp, the lamp housing is made of synthetic resin and has a material plating (for example, chrome plating). A protector is attached to the edge portion that comes into contact with the vehicle body panel. This protector is a soft synthetic resin or rubber molded product that is extruded or injection molded.

Conventionally, in order to attach this protector to the periphery of a lamp housing, etc., adhesive was applied to the inner bottom of the protector, the protector was fitted along the periphery of the housing, temporarily fixed with adhesive tape, etc., and then attached to the inside of the opening. It is attached to a lamp housing, etc. by applying an adhesive and mechanically caulking it.

In such conventional vehicle lamps, the protector is a molded product made of synthetic resin or rubber, which is molded in advance using a molding machine, and then coated with adhesive, adhesive tape, adhesive, mechanical caulking, or Because the fixing and mounting process involves a combination of these, the factory that manufactures the protector and the factory that assembles the protector to the rim, housing, etc. are usually separate factories, and there is also a risk of adhesive flowing out, adhesive There were problems such as dirt caused by the protector, peeling due to the repulsive force of the protector itself, and a long holding time required for the protector to develop adhesive strength.

Furthermore, depending on the type of adhesive, special consideration is required for worker health management.

Therefore, the present applicant aimed to improve the conventional vehicle lamp as described above, and developed a housing.

A vehicle lamp in which a protector made of a heat-melting elastic material is integrally molded on the peripheral edge of the rim, lens, etc.
No. 01) was filed earlier and is now publicly known.

In order to configure a protector around the lamp housing by applying the above-mentioned known technology, first, surface treatment is applied to the cavity of a mold made of metal such as iron or aluminum or heat-resistant synthetic resin (hereinafter referred to as the mold). Or apply a silicone mold release agent.

Next, a ready-made lamp housing is set in a mold, the lamp housing and the mold are mechanically tightened, and a nozzle is connected to the injection hole of the mold via an applicator and a pump, Inject the elastic body.

Then, the heat-melting elastic body is injected along the gap at the periphery of the lamp housing set in the mold. Once the heat-melting elastic material is sufficiently filled, the pump and nozzle are removed from the injection hole, and the heat-melting elastic material is assimilated by forced cooling or natural cooling, and the mold is untightened to form the lamp housing. The vehicle lamp and protector are integrated to provide a vehicle lamp.

Such vehicle lamps utilize the fluidity at high temperatures and solidified shape retention properties at low temperatures of the heat-melting elastic material to form a protector integrally with the lamp, so there is no possibility of stains due to adhesive, shape defects, etc. Since problems such as adhesive leakage are eliminated and the process is simplified, assembly costs can be significantly reduced, and there are no health problems for workers related to adhesives. In addition, since it is a low-pressure molding method, the equipment and molds are simple, and costs can be reduced.

FIG. 4 is a sectional view showing a conventional example of a vehicle lamp equipped with a protector.

A hot melt groove 1a is formed in the opening of the lamp housing 1, the leg 2a of the front lens 2 is inserted into the hot melt groove 1a, and the gap is filled with adhesive (hot melt) 3. There is. 4 is a light source bulb.

In order to attach this lamp to the vehicle body panel 5, a protector 6 is integrally molded on the outer periphery of the opening of the lamp housing 1, specifically, on the outside of the hot melt groove 1a.

FIG. 5 is an explanatory diagram showing a state in which a protector is integrally molded by applying the above-mentioned known technique.

A ready-made lamp housing 1 is inserted between a mold (A) 7 and a mold (B) 8.

The mold (A) 7 is provided with a cavity 7a in contact with a flange-shaped portion on the outer periphery of the lamp housing l.

When the heat-melting elastic material is injected into the cavity 7a, the protector is molded integrally with the lamp housing 1.

As shown in FIG.
When a protector is formed by injecting a heat-melting elastic material into the cavity 7a adjacent to the flange-like part 1b, the synthetic resin forming the lamp housing and the protector forming the lamp housing are There is a problem that if there is no affinity between the heat-melting elastic body and the heat-melting elastic body, the two will not be bonded together.

If the protector is not attached to the flange-shaped portion on the outer periphery of the lamp housing, it is not easy to assemble a vehicle lamp using the lamp housing. Also 1
Not only is it inconvenient to transport and store the assembled light until it is attached to the vehicle body, but also the installation work is difficult. That is, even when an experienced person performs the installation work, a considerable amount of care and effort is required, and when an unskilled person performs the installation work, there is a risk that the protector may come out or the protector may not stick properly, resulting in poor installation.

However, the synthetic resin material used to mold the lamp housing is
In addition to the physical properties necessary for injection molding, heat resistance, rigidity, and strength are also required. This is because if the heat resistance is insufficient, when the vehicle lamp is used, there is a risk that the lamp housing may become heated and deformed due to the heat generated by the light source lamp.

Furthermore, the heat-melting elastic material used to mold the protector must have rubber-like elasticity and durability to function as a sealing packing, in addition to the physical properties necessary for injection molding. This is because if it lacks rubber-like elasticity or becomes hardened or brittle due to aging, it will no longer function as a protector.

If one tries to select the material of the lamp housing and the material of the protector within the range of such selection conditions, it is difficult to make both materials compatible or compatible.

For example, ABS (acrylonitrile-butadiene-styrene resin) is suitable as a molding material for lamp housings, and thermoplastic elastomer is suitable as a molding material for protectors, but since ABS and thermoplastic elastomers have no affinity, they are mutually compatible. I don't wear it.

In particular, if metal plating (for example, chrome plating) is applied to the flange-shaped portion of a lamp housing molded from a synthetic resin material, it will not fuse with all currently known thermofusible elastic materials.

In view of the above-mentioned circumstances, when a pre-formed lamp housing is sandwiched between two molds and a protector is injection molded into the cavity provided in the molds, there will be a gap between the lamp housing molding material and the protector molding material. In order to ensure that both parts are mechanically joined to each other even if there is no affinity, a flange-like shape is provided on the outer periphery of a pre-formed synthetic resin (or metal-plated) lamp housing. When molding is performed by sandwiching the part between two molds and injecting a hot-melt elastic material into a cavity provided in at least one of the two molds in contact with the flange-shaped part, It is conceivable to provide the flange-shaped portion of the lamp housing with projections and depressions in advance. As a result, the protector is formed with convex and concave portions having a shape that is an inversion of the above-mentioned concave and convex portions, and both of the concave and convex portions fit together, and a mechanical bonding effect is expected. That is, in a vehicle lamp in which a protector is injection-molded in contact with a flange-shaped portion of a lamp housing, the protector has a U-shaped cross section and is in contact with the front surface, outer peripheral side surface, and back surface of the flange-shaped portion. Further, the flange-shaped portion is provided with a through hole that communicates the front surface and the back surface, and the protector is provided with a columnar portion that connects two parallel U-shaped surfaces, and the columnar portion is provided with the above-mentioned columnar portion. If the configuration is such that the through hole is fitted into the through hole, the through hole provided in the flange portion on the outer periphery of the lamp housing and the columnar portion provided in the protector are fitted, so that the flange portion of the lamp housing is fitted. and the protector are mechanically engaged.

Therefore, even if there is no affinity or compatibility between the materials that make up the lamp housing and the materials that make up the protector, since both members are mechanically engaged, they are easy to handle, and the protector After manufacturing the lamp housing, it is easy to attach the component parts for the lamp and assemble the lamp, and in addition, the assembled lamp is transported.

It is easy to store, and the assembly of the assembled light fixtures onto the vehicle body is quick and requires no skill.

Can be easily assembled. This structure was devised by the present inventors and is currently being applied for separately (Utility Application No. 2-3134). (hereinafter referred to as the invention of the earlier application).

FIG. 6(A) is a cross-sectional view of a vehicle lamp equipped with an embodiment of the protector mounting structure according to the invention of the prior application.

Front lens 2 with the same drawing reference numbers as the conventional example. Light source bulb 4. The vehicle body panel 5 is the same or similar component to that in the conventional example.

An enlarged detailed view of part B of FIG. 6(A) is shown in FIG. 6(B).

A hot melt groove 1a is formed around the front opening of the lamp housing 1'. Legs 2a integrally molded on the front lens 2 made of synthetic resin are inserted into the hot melt grooves 1a and bonded with hot melt 3, which is a thermoplastic adhesive.

A flange-like portion 1b is formed on the outer peripheral side of the hot-melt groove 1a in the lamp housing 1', and a protector 9 having a U-shaped cross section is disposed in contact with the front, outer and back surfaces of the flange-like portion 1b.

A through hole 1 that communicates between the back and front surfaces of the flange-shaped portion 1b.
c is provided.

On the other hand, the protector 9 is formed with a columnar part 9a, which fits into the above-mentioned through hole 1c.

The protector mounting structure of this example is configured as described above, and even if there is no affinity or compatibility between the two materials, the protector 9 is mechanically bonded to the flange-shaped portion 1b of the lamp housing and can be easily peeled off. do not.

In this way, the protector 9 is attached to the lamp housing 1'.
Since it is attached to the flange-like portion 1b of the lamp housing 1', the work of assembling the vehicle lamp is to attach the components of the lamp (for example, the light source bulb 4° and the front lens 2 shown in FIG. 6(A)) to the lamp housing 1'. Easy to do.

In addition, it is easy to transport and store assembled vehicle lights, and in particular, it is easy to assemble one assembled vehicle light to the vehicle body, and it can be quickly assembled without requiring any skill. There is no risk of assembly defects such as sticking out or not sticking properly.

FIG. 7 is a partially cutaway perspective view of the lamp housing 1'.

FIG. 8 is an explanatory diagram of a method of constructing the protector mounting structure of the invention of the prior application shown in FIG. 6, and is a diagram corresponding to FIG. 5 in the above-mentioned known example.

Molds with the same drawing reference numbers as in the known examples (A
)7. The cavity 7a and the mold (B) 8 are the same members as in the above-mentioned known example.

The lamp housing 1' is a member corresponding to the lamp housing 1 in the above-mentioned known example, but the lamp housing 1' of this example is provided with a through hole IC on the back side (lower side in the figure) of the flange-shaped portion 1b. .

With the above setup, as in the known example, a nozzle (none of which is shown) is connected to the injection hole provided in the mold via an applicator and a pump, and the thermofusible elastic material is injected. . Then, the heat-melting elastic body is injected along the gap around the periphery of the lamp housing set in the mold. Once the heat-melting elastic material is sufficiently filled, the pump and nozzle are removed from the injection hole, and the heat-melting elastic material is solidified by either forced cooling or natural cooling, and the mold is untightened to form the lamp housing. A member is obtained in which the and protector are integrated, and the molded protector has a through hole I.
A columnar portion corresponding to C is formed.

As described above, the protector mounting structure of this example is different from the mold (A) for molding the protector in the conventional example by providing a through hole in the flange-shaped portion 1b of the lamp housing 1'.
7. Since it can be constructed using the mold (B) 8,
It can be applied to industrial production without making major modifications to existing equipment.

As explained above, the protector mounting structure for a vehicle lamp according to the invention of the prior application can be produced using existing equipment without making major modifications to the conventional protector injection molding equipment. Even if there is no affinity or compatibility between the constituent materials of the lamp housing and the protector, since the lamp housing and the protector are engaged, the combined state is maintained without separation.

Therefore, assembly work for constructing a vehicle lamp by assembling lamp components into the lamp housing can be easily performed.

Moreover, the assembled vehicular lamp can be easily packed for transport and is extremely easy to handle during transport.

In particular, when the assembled vehicle lamp is assembled to the vehicle body, there is no risk of the protector shifting from a predetermined position or protruding because the protector is fixed and adhered to the flange-shaped portion of the lamp housing.

Therefore, the vehicle lamp can be quickly and easily assembled to the vehicle body without requiring special skill, and there is no risk of assembly defects such as misalignment of the protector, protrusion of the protector, or poor adhesion of the protector. None.

In the protector mounting structure according to the invention of the earlier application, the more places that are provided on the flange part of the lamp housing and are fitted with the columnar parts of the protector, the more stable the fixed state will be, but increasing the number of fitting places will increase the manufacturing cost. It is relatively expensive, and if the number of fitting parts is reduced, there is a problem that the fixing state becomes unstable.

In view of the above-mentioned circumstances, the protector that is brought into contact with the flange-like part of the lamp housing is fixed to the flange-like part of the lamp housing, either in combination with the mounting structure according to the invention of the earlier application or independently. obtain. The purpose of the present invention is to provide a method for molding a protector, and in particular, to improve the ability to mold a protector by fixing it to a chrome-plated lamp housing, which has been considered extremely difficult with the prior art. A resist containing toluene and methyl isobutyl ketone as main components is applied to the portion that comes into contact with the protector, and the lamp housing is chrome plated.

It is advantageous to injection mold the protector with a thermoplastic elastomer. The above method was created by the present inventors and is currently being applied for separately (Japanese Patent Application No. 2-100435).
(hereinafter referred to as the invention of the earlier application).

According to the method of the invention of the earlier application, chrome plating does not adhere to the resist-coated surface.

Moreover, when the molten thermoplastic elastomer contacts and solidifies, the thermoplastic elastomer adheres to the flange portion of the synthetic resin lamp housing due to the action of the applied resist.

As a result, a lamp housing to which the protector is fixed is obtained, and subsequent operations such as transportation, storage, and assembly are easy, and there is no risk of the protector being displaced during assembly.

Even when the invention of this prior application is applied to the protector having the conventional mounting structure shown in FIG. 4, sufficient practical effects can be obtained.

In addition, if used together with the protector mounting structure according to the invention of the earlier application shown in FIGS. 6(A) and (B), the fixing reliability will be even higher, and even if the number of through holes 1c is reduced, it will not be practical. A sufficient adhesion effect can be obtained.

〔Example〕

9 to 11 are process diagrams showing an embodiment of the invention of the prior application.

FIG. 9(A) is a cross-sectional view showing the vicinity of the flange-shaped portion 1b of the lamp housing 1, which is a target member for forming a protector gloss by applying the invention method of the prior application.

The imaginary line S indicates the location where the protector should be molded and fixed.

A resist 10 (indicated by broken lines) containing toluene and methyl isobutyl ketone as main components is applied to the surface where the flange-shaped portion 1b of the lamp housing 1 contacts the above-mentioned portion S where the protector is expected to be formed.

In this example, the liquid wrapping paper 3 on the back of Isamu Paint Co., Ltd.
364 Green was applied by brushing.

When practicing the present invention, any coating method can be used, such as applying the resist with a spray gun.

When nickel plating (Ni) (indicated by chain lines) is applied to this lamp housing 1, the nickel plating will not adhere to the areas where the resist 10 is applied.

The lamp housing 1 pre-treated as described above is
It is sandwiched between a mold (A) 7 and a mold (B) 8 as shown in FIG. 10(B), and a molten thermoplastic elastomer 11 is injected into the space 7a as shown in FIG.

In this example, AR-5-1230 manufactured by Aron Kasei Co., Ltd. was used as the thermoplastic elastomer.

When the thermoplastic elastomer is cooled and solidified and taken out from the mold (see FIG. 11), a protector 11' fixed to the flange-shaped portion 1b of the lamp housing 1 is obtained.

In the above-described operation, the resist lO applied to the flange-like portion 1b prevents the adhesion of nickel plating on the armpit portion, exposes the synthetic resin surface, and fixes the thermoplastic elastomer to the exposed surface.

The above-mentioned embodiments (FIGS. 9 to 11) apply the method of the present invention to the protector of the conventional mounting structure (FIG. 4), and the lamp housing 1 is assembled without using adhesive.
A protector fixed to the flange-like portion 1b was obtained, as shown in FIG. 6(A).

The invention method of the earlier application can also be used in conjunction with the protector having the mounting structure according to the invention of the earlier application shown in (B).

In this case, by combining the invention of the earlier application, the adhesion reliability of the protector is further improved, and there is no risk of the protector coming off from the lamp housing even if it is roughly handled, making it convenient for transportation and storage. be.

Since there is no need to use adhesive, the work of attaching the protector to the flange portion of the lamp housing can be done quickly and easily.

Furthermore, since there is no need to use an adhesive, there is no risk of health care problems related to the toxicity of the adhesive.

Furthermore, there is no risk of damaging the appearance due to the adhesive sticking out.

[Problem to be solved by the invention]

Although the invention and the device according to the above-mentioned prior application have excellent effects regarding the connection between the protector and the lamp housing, there are the following problems regarding the portion of the protector that is not in contact with the lamp housing.

That is, the mold (A) 7 of the prior art (Fig. 5) and the mold (
B) 8 is also used in the invention of the earlier application (FIG. 8) and the invention of the earlier application (FIG. 2).

The inner surface of the protector molding cavity (for example, 7a) provided in the mold has conventionally been generally mirror-finished.

For this reason, a thin smooth layer called a skin layer is formed on the externally visible surface of the molded protector.

Although this layer is shiny and beautiful, it is very easily damaged and loses its luster even when touched with a fingertip, for example.

According to the research and experiments conducted by the present inventors, the gloss is not restored even if the parts that have lost their luster are washed, so they are considered to be microscopic scratches rather than stains.

As a result, the luster of the part that is held in the hand is lost and becomes mottled, which significantly impairs the appearance and reduces the value of the part.

In order to eliminate the negative effects of such spots, attempts have been made to rub the surface of the protector with a cloth or brush to eliminate the gloss on the entire surface (meaning all the parts that appear on the outside).
In addition to requiring a lot of time and effort, it is not easy to remove the gloss uniformly.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a method for molding a protector that does not cause a change in appearance and become mottled even when it comes into contact with other members, such as when touched by hand. purpose.

[Means to solve the problem]

An outline of the basic principle of the present invention created to achieve the above object is as follows.

That is, when a protector molded according to the prior art is touched, its appearance changes because countless microscopic scars are generated on the touched portion.

Therefore, if countless fine irregularities are formed on the entire surface of the protector (meaning the entire surface that appears on the outside) before the protector is touched, the traces of the touch will not be noticeable.

As a specific method based on the above-mentioned principle, the method for molding a protector for a vehicle lamp according to the present invention is a method of injection molding a protector in contact with a flange-shaped portion of a lamp housing made of synthetic resin, which includes injection molding of the protector. At least a portion of the inner surface of the protector molding cavity of the mold is honed, and the protector is injection molded with thermoplastic elastomer.

In the present invention, honing does not mean honing in the narrow sense of grinding a cylindrical surface with a grindstone, but includes a processing method in which abrasive grains are sprayed with a fluid.

[Effect]

According to the above method, the inner surface of the cavity in which the protector material is to be injected and molded is honed to form countless minute irregularities, so the surface of the protector that is injected and molded into this cavity is Countless microscopic irregularities are formed, resulting in a so-called matte state. Therefore, even when touched with a finger, the gloss does not change.

〔Example〕

FIG. 1 is a schematic cross-sectional view for explaining the protector molding method according to the present invention.

As shown in FIG. 1(A), the mold (A) 12 and the mold (B
) 13 and insert the lamp housing 1 between them.

The above mold has a flange-like portion 1b of the lamp housing.
A cavity 12a is provided at the outer periphery of the cavity 12a, and microscopic irregularities are formed on the inner peripheral surface by honing.

In this example, honing was performed by spraying abrasive grains with a particle size of 60 to 80 with compressed air. Therefore, although the microscopic irregularities on the honed surface are microscopic, the accompanying drawings depict these microscopic irregularities in an enlarged manner.

As shown in FIG. 1(B), when the thermoplastic elastomer 11 is injected into the cavity 12a, solidified, and taken out from the mold, its surface has microscopic irregularities as shown in FIG. 1(C). A protector 14 is formed.

Because it has microscopic irregularities, it is matte, and the gloss does not change even if you touch it with your fingers.

FIG. 2 shows an embodiment different from the above, and is a diagram corresponding to FIG. 1(B) in the embodiment.

In this example, a cavity 15a is formed by a mold (A) 15 and a mold (B) 16, and the inner peripheral surface of this cavity 15a is honed. The cavity 15a in this example is configured such that the injected thermoplastic elastomer 11 covers the outer peripheral half of the front surface (the upper surface in the figure) of the flange-shaped portion 1b of the lamp housing 1.

FIG. 3 shows a further different embodiment from the above.

In this example, a cavity 17a is formed by a mold (A) 17 and a mold (B) 18, and the inner peripheral surface of this cavity 17a is honed. The cavity 17a in this example is configured such that the injected thermoplastic elastomer 11 covers the entire outer peripheral side of the front surface (upper surface in the figure) of the flange-shaped portion 1b of the lamp housing 1.

These embodiments (FIGS. 2 and 3) also provide the same effect as the embodiment described above (FIG. 1).

〔Effect of the invention〕

According to the method for molding a protector for a vehicle lamp according to the present invention, even if the molded protector is touched with a fingertip, the gloss will not change and the product will have a mottled appearance, which will not damage the product value.

[Brief explanation of drawings]

FIGS. 1(A) to 1(C) are schematic cross-sectional views for explaining steps in an embodiment of the protector molding method according to the present invention. FIGS. 2 and 3 are explanatory diagrams of embodiments different from those described above, respectively. 4 and 5 show a conventional vehicle lamp, with FIG. 4 being an overall sectional view and FIG. 5 being an explanatory diagram of a construction method. FIGS. 6(A), 6(B) to 8 are explanatory diagrams of the invention related to the prior application. FIGS. 9 to 11 are explanatory diagrams of the invention related to the order of precedence. 1.1'...Lamp housing, 1a...Hot melt groove, 1c...Through hole, 2...Front lens, 2a...
··leg. 3...Hot melt, 4...Light source bulb, 5...
Vehicle body panel, 6... Conventional protector, 7... Mold (A), 8... Mold (B), 9... Protector constructed by applying the invention of the prior application, 9a...・Columnar part, 10・
...Resistor, 11...Thermoplastic elastomer, 12.
...Mold (A), 12a...Cavity, 13...Mold (
B), 14...Protector, 15...Mold (A)
, 15 a-cavity, 16-... mold (B), 17-...
・Mold (A), 17 a-cavity, 18...Mold (B
).

Claims (1)

[Claims] 1. In a method of injection molding a protector in contact with a flange-shaped portion of a synthetic resin lamp housing, at least a portion of the inner surface of the protector molding cavity of the injection molding mold for the protector is provided. A method for molding a protector for a vehicle lamp, characterized in that the protector is injection molded using a thermoplastic elastomer after being honed.