JPS6326931Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealed beam lamp comprising a lens and a reflector bonded together with an adhesive.

Conventionally, sealed beam lamps used under harsh conditions were so-called welded type sealed beam lamps, in which the lens and reflector were each molded from glass, and the peripheral edges of each were heated and melted to join them. In recent years, a lens and a reflector bonded together with an adhesive has been proposed.

FIG. 1 is a cross-sectional view of the main parts of an example of a conventional adhesive type sealed beam lamp, in which a joint surface b has a protrusion c formed on the periphery of a reflector a.
The joint surface f having the protrusion g of the lens e is joined to the lens e through an adhesive d in a substantially watertight manner. As mentioned above, sealed beam lamps are used under harsh conditions, so Adhesive d has an adhesive function under a wide range of temperature conditions, such as -40 to +80 degrees Celsius. Conventionally, epoxy adhesive d has been used.

However, in order for the adhesive function to work under a wide range of temperature conditions, with conventional epoxy adhesives d, the adhesive film thickness t in the bonded state must be at least
Reliable adhesive strength cannot be obtained unless the thickness is 2.0 mm or more. For this reason, not only is a large amount of adhesive d required, resulting in high costs, but also the application of a large amount of adhesive d causes it to protrude after bonding and stain the reflective surface of the reflector. In addition, epoxy adhesive is 120
Equipment such as a drying oven is required to dry (cure) at a high temperature of ~150℃, and the curing time is 40~
It takes about 60 minutes, and in addition, the solvent contained in the epoxy adhesive d whitens the reflective surface of the reflector A, which is formed by vapor-depositing aluminum etc., by processing at high temperatures, reducing the reflection efficiency. There is a problem with storing it away. Conventionally, both the reflector a and the lens e are of the welded type, so there is a problem that the adhesive d cannot be applied uniformly due to the protrusions c and g formed on the respective joint surfaces b and f. be.

In view of the above circumstances, an object of the present invention is to provide a novel sealed beam type lamp that uses a small amount of adhesive and has a stable quality, which can provide sufficient adhesive strength even under a wide range of temperature conditions.

In order to achieve the above-mentioned purpose, this invention
In a sealed beam type lamp in which a lens and a reflector are bonded together with an adhesive, the adhesive is an ultraviolet curing adhesive and the adhesive film thickness is 1.5 mm.
It is characterized by the following.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 5.

FIG. 2 is a horizontal sectional view of a lamp showing an embodiment of the present invention, and FIG. 3 is an enlarged sectional view of section A in FIG. The reflector 1 is made of glass, synthetic resin, or metal, and has an approximately paraboloid-shaped reflective surface formed by vapor-depositing aluminum or the like on its inner surface, and has a plurality of inner supports 11, 11 inside. The valve 12 is held through the valve.
The bulb 12 is a halogen bulb in this example. A flat bonding surface 13 is formed at the periphery of the front opening of the reflector 1, and the lens 2 is bonded to the bonding surface 13 via an ultraviolet curing adhesive 3. Lens 2 is made of glass or transparent synthetic resin,
For example, it is made of synthetic resin such as polycarbonate or acrylic, and is composed of a lens surface 21 on which a large number of prisms are formed, and a side wall leg 22 rising from the periphery of this lens surface 21.
A flat joint surface 23 is formed on the periphery of the reflector 2, and the joint surface 23 is joined to the joint surface 13 of the reflector 1 as described above.

In this invention, we use an ultraviolet curing adhesive 3 that hardens when irradiated with ultraviolet rays as an adhesive, and also control the bonding state, that is, the adhesive film thickness t after curing.
Set to 1.5mm or less.

The above-mentioned ultraviolet curable adhesive is, for example, "Aronix UV-3282", a trade name of Toagosei Kagaku Co., Ltd., which contains a resin component, an organic solvent, and a photopolymerization initiator as essential components, and its composition ( before curing)
The physical properties are: white viscous liquid, non-volatile content;
99% or more, specific gravity: 1.16, viscosity: 40000cps (25℃)
The physical properties after curing are: appearance: white translucent, specific gravity: 1.27, volume shrinkage: 8.7%, tensile strength: 77
Kg/cm ² , Shore hardness: D-80.

According to the results of an experiment in which a glass reflector and a glass lens were bonded using the ultraviolet curable adhesive 3 as described above, the adhesive film thickness t in the bonded state of the ultraviolet curable adhesive 3 was 1.5 mm. If the temperature exceeds 1.5 mm, cracks occur in the adhesive 3 when the temperature is returned to room temperature from -40°C, resulting in the inability to maintain a watertight state. It did not occur. Therefore, an amount of ultraviolet curable adhesive 3 is applied to the bonding surface 13 of the reflector 1 so that the adhesive film thickness t is 1.5 mm or less in the bonded state (state after curing), and the lens 2 is bonded thereon. When the surface 23 is placed and pressed, the ultraviolet curable adhesive 3 spreads between the bonding surfaces 13 and 23, and then when ultraviolet rays are irradiated for 1 to 2 minutes, the adhesive hardens and makes the reflector 1 and lens 2 watertight. It can be firmly and firmly bonded.

FIG. 4 shows a modification of FIG. 3, in which A is an exploded cross-sectional view before joining, and B is a cross-sectional view in a joined state. In this example, a recess 14 is formed on the outside of the periphery of the reflector 1 so that the lens 2 and reflector 1 can be positioned as set during bonding, and a recess 14 is formed in the side wall leg 22 of the lens 2.
A protrusion 24 is formed at a position corresponding to the protrusion 24 so that the protrusion 24 fits into the recess 14. The protrusions 24 do not necessarily have to be provided all around, and may be provided partially. Then, as shown in FIG.
mm or less, the height of the protrusion 24 or the depth of the recess 14 is set so that a gap t' of 1.5 mm or less is generated between the protrusion 24 and the recess 14. Note that the ultraviolet curing adhesive 3 may flow into the gap t'. Note that the protrusion 24 and the recess 14 are not limited to the positions shown in this example, but may be provided on the inside as shown in FIG.
may be provided outside the periphery of the reflector 1. Furthermore, as shown in FIG.
The protrusion 24 provided on the inside of the reflector 1 protrudes into the inside of the reflector 1, or the protrusion 24 provided on the inner side of the periphery of the reflector 1 as shown in E of the same figure.
may be formed so as to protrude along the side wall leg portion 22.

According to the present invention, since an ultraviolet curing adhesive 3 is used as the adhesive, the curing time is greatly shortened, greatly improving productivity, and equipment such as a drying oven is not required, simplifying the equipment. In addition, since heat treatment is not performed for curing, even if the ultraviolet curable adhesive 3 contains a solvent or the like, the reflection efficiency of the reflective surface of the reflector 1 due to whitening phenomenon will not be reduced. Moreover, since the UV-curable adhesive 3 has an adhesive film thickness t of 1.5 mm or less, it provides stable adhesive function without causing cracks even under a wide range of temperature conditions, and the amount of application is small. It is possible to reduce costs and prevent the reflective surface of the reflector 1 from becoming dirty due to protrusion.

Note that the present invention is not limited to the above example, and the valve 12
It may be a sealed beam type lamp in which the reflector 1 is held so that it can be attached or removed from the rear of the reflector 1, or it may be a type in which the filament is supported directly on the inner supports 11, 11.

As mentioned above, the sealed beam lamp in which the lens and reflector are bonded with adhesive according to the present invention uses an ultraviolet curing adhesive and the adhesive film thickness is 1.5 mm or less, so it can be used over a wide range of temperatures. Adhesive strength is sufficiently reliable even under various conditions, and since the amount used is extremely small, it is possible to prevent contamination of the reflective surface of the reflector due to protrusion, and the manufacturing time is significantly shortened, resulting in excellent quality. This has the effect of making it possible to obtain a sealed beam type lamp.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing a conventional example. Second
3 and 3 show an embodiment of the present invention, FIG. 2 is a horizontal sectional view of a sealed beam lamp, FIG. 3 is an enlarged view of section A in FIG. 2, and FIG. 4 is a modification of FIG. 3. An example is shown in which Figure A is an exploded cross-sectional view before joining, and Figure B is a cross-sectional view in a joined state. FIGS. 5A to 5E are exploded sectional views before joining, each showing a modification of FIG. 4. 1...Reflector, 13...Joint surface, 2...
Lens, 23... Bonding surface, 3... Ultraviolet curing adhesive, t... Bonding film thickness.

Claims (1)

[Scope of utility model registration request] In a sealed beam type lamp in which a lens and a reflector are bonded together with an adhesive, the adhesive is a radiation-curable adhesive and the adhesive film thickness is
A sealed beam type lamp characterized by having a diameter of 1.5mm or less.