JPS6166358A - Junction type beam lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates generally to incandescent light sources, and more particularly to a junction beam lamp having a two-piece envelope including a reflector and lens assembled by adhesive means. The reflector has an internally reflective coating for reflecting and directing light generated by a light source disposed within the envelope to a cooperating lens for transmission therein.

BACKGROUND OF THE INVENTION Parabolic aluminized reflectors (PAR) have been used for conventional spot or floor lighting applications.
c aluminized rector)
The lamp also has an elliptical shape (ER: ell).
The use of ipticalrcrlcclor > lamps is well known in the art. In particular, the parabolic aluminized reflector lamp and (11 circular reflector lamp) are suitable for outdoor use at short and medium distances as well as for exhibition, decoration and
For indoor use for highlighting, inspection, downward illumination applications, etc.] (= always popular. Lamps of this type are manufactured and sold by the assignee of the present invention. Typically,
This type of lamp is made of hard glass and has an intermediate skirt (
It has a screw-shaped) or side bottle-shaped base.

However, manufacturing this type of generally circular glass reflector and lens assembly can present various problems. for example,
Stresses created in the glass lens and reflector during assembly by melt sealing (ie, flame sealing) can lead to cracking here. Flame sealing methods are expensive and require the use of equipment that is difficult to operate. Points of thermally generated stress can cause breakage of the reflector or lens, and subsequently cause a loss of sealing in the event of breakage of the light source capsule arranged in the lamp. These problems are particularly acute in outdoor applications where large thermal gradients are imposed on parabolic aluminized reflector lamps or ellipsoidal reflector lamps. Experience gained in tests involving automotive headlight design shows that thermally induced stresses of this type
It has been found that significant reductions can be achieved by using adhesives rather than flame seals to seal the glass reflector and lens together.

In the design of automotive headlights, the nature of the lens-reflector seal is highly dependent on the appropriate combination of the coefficient of thermal expansion of the lens J5 and reflector material used and the coefficient of thermal expansion of the adhesive. Typical thermal expansion coefficients of hard glasses used in headlights, e.g. borosilicate, and suitable adhesives for lamp glassware, e.g. a typical 1% thermal expansion of softened epoxy polymers. The rate is approximately 1
There may be an order of magnitude difference. The glass-to-adhesive seal causes the glass portion to shrink at a significantly different rate than the adhesive portion when exposed to decreasing ambient temperatures. This type of variation in shrinkage results in weakening of the lens-to-reflector seal or stresses that cause cracking of the glass. Similarly, in other lamps where the lens and reflector must be joined to form a sealed envelope, the coefficient of thermal expansion of the lamp envelope material must be and lens
An appropriate combination of thermal expansion and elongation of the adhesive for sealing the reflector is important.

Therefore, there is a need for a lamp that can be assembled and exited in a manner that significantly reduces thermally induced distortions in either the lens or the reflector, as opposed to conventional flame seal techniques. This type of lamp would be a significant advance if higher wattage light source capsules could be used without concern that the additional heat generated would cause strain-induced damage.

OBJECTIVE OF THE INVENTION 1 Accordingly, the principal object of the present invention is to improve the technology of incandescent lamps, especially junction beam lamps, which operate at high wattages and are subject to large thermal gradients.

Another object of the invention is to provide a junction beam lamp which can be used satisfactorily in harsh outdoor applications without the risk of rapid temperature changes causing damage to the lamp envelope.

Yet another object of the invention is to provide a bonded beam lamp that successfully accommodates glass fragments resulting from breakage of a light source capsule disposed within the lamp.

[Summary of the Invention] According to one aspect of the present invention, an envelope having a reflector and a lens made of substantially similar materials having predetermined coefficients of thermal expansion; a substantially enclosed light source disposed between the lens and the reflector, sealing them together, having a curing temperature equal to or greater than the operating temperature of the lamp and a coefficient of thermal expansion greater than that of the lens and reflector materials; An electric lamp is provided, comprising: an adhesive means having a bonding means;

According to another aspect of the present invention, there is provided a method for manufacturing an electric lamp having an envelope formed of a lens and a reflector, the lens-reflector having a sealing surface around the periphery thereof,
In this method, the reflector is aluminized, the light source is placed inside the reflector, the adhesive means is placed on the sealing surface of the lens, the lens sealing part and the reflector sealing surface are joined, and the temperature is set at a temperature equal to or equal to the operating temperature of the lamp. Adhesive means having a high curing temperature and a higher coefficient of thermal expansion than the materials forming the lens and reflector are cured at about 148° C.
It includes curing stages to a temperature in the range of 90'C.

[Detailed Description of Preferred Embodiments] Preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 illustrates an electric lamp 10 made in accordance with the present invention. Electric lamp 10 comprises an envelope 11 formed by a lens 12 and a cooperating reflector 14, a light source 16 and a base 18. Lens 12 and reflector 14 are joined by adhesive means 15 to form a single lens-reflector seal for lamp 10. The lens 12 and the reflector 14 can be formed by compressing hard glass during molding subsequent to annealing. Lens 12 typically has a slightly convex outer surface, eg, enveloping a centrally located stippled portion formed on the inner surface? The several radial grooves that define the j4 joint have optical definition provided.

This is discussed in the aforementioned U.S. Patent Application No. 524.5.
Please refer to the specification of No. 07. The reflector 14 also has a concave inner surface 13 provided with a light reflective coating, typically comprising aluminum or silver.

The reflector 14 is preferably a parabolic reflector, but may also be an elliptical reflector.

Lens 12 and reflector 14 preferably have a generally circular circumference j and each have directions 1 and j disposed near this circumference.

As previously mentioned, flame seals such as those caused by flames directed toward the sealing surface of the glass reflector, lens, etc., can create an unacceptable response pattern in the outer shell 11. . In particular, stress tends to be concentrated near the lens-to-reflector seal 19, thus causing cracks near this area. The stresses generated by the flame seal can be significantly reduced by sealing the lens 12 and reflector 14 by inserting adhesive means 15 between the previous peripheral sealing surfaces. Adhesives suitable for the intended use herein are those that have a curing temperature equal to or higher than the operating temperature of the lamp and a higher coefficient of thermal expansion than the lens and reflector materials. An example of this type of adhesive is °“Uniset (UN rsET) 3002-14”.
,! : is a thermally convertible epoxy resin called Xin(]tO
Tail, which is commercially available from Amicon Corp. (n).

The electric lamp 10 is a tungsten-halogen power duck (
The capsule has an envelope containing an inert gas filling and a halogen. The capsule 16 is disposed inside and is substantially surrounded by the reflector 14.
It is approximately perpendicular to the lens 12. The capsule 16 is attached to and held by the attachment member 16. The reflector 14 has two fitting holes 22 through which the capsule can be inserted.
The mounting member assembly is inserted and secured by an eyelet-epoxy-washer connection. Each lead wire of the mounting member 20 is fixed in the six fitting holes 22 with an eyelet 24, an epoxy resin 26, and a bolt 1728. lamp 1
0 has a diode 30 and a fuse wire 32 coupled in series to the capsule 16 and base 18. The envelope 11 of the lamp 10 comprises an exhaust hole tube 34 and a small steel ball bearing 35 which serves as a plug.

The envelope 11 illustrated in FIG. 1 is an example C of a lamp envelope that can contain glass shards resulting from a possible, but infrequent, crack in the capsule.

Testing showed that of 60 lamp envelopes formed by the method described herein, all lamps effectively contained glass shards resulting from intentionally induced capsule rupture. Out of 50 lamps produced by the flame seal method, 3 lamps failed to contain the glass shards resulting from the intentionally caused capsule rupture. Thus, the above-described sealing method provides a lamp envelope that reliably contains glass fragments resulting from possible, but infrequent, cracking of the capsule 16.

Referring to FIG. 2, a partial cross-sectional view of a lens-reflector seal 19 having a groove-shaped lens sealing surface A and a reflector sealing surface B is illustrated, and these sealing surfaces are connected to the lens 12 and the reflector sealing surface B, respectively. It is arranged around the reflector 14. During assembly of the electric lamp 10, the adhesive means 15 is attached to the sealing surface A.
, placed between 8. The sealing surface A1B is bonded when the lens 12 and reflector 14 are pressed together. The lamp 10 is then applied with about 5 ml of water to cure the adhesive means 15.
A heat curing temperature in the range of about 148° C. to 190° C. is applied for ˜40 minutes.

The contact between the sealing surfaces A and B is caused by an inappropriate combination of the different coefficients of thermal expansion of the glass and adhesive means used.
Can deteriorate rapidly over time. For example, the coefficient of thermal expansion of borosilicate glass commonly used in automotive sealed beam headlights is typically approximately 40X 10"' 70I
112/°C. Additionally, the coefficient of thermal expansion of a standard flexible epoxy resin suitable for sealing headlight glass fixtures is typically approximately 40 x 10-60 m2/°C.
be. In other words, the coefficient of thermal expansion of the glass 1113 of the sealed beam headlight and the contacting means differ by about one order of magnitude G. Temperature changes, especially at decreasing temperatures, therefore lead to differences in the rate of shrinkage between the glass and the intermediate bonding means, creating significant stresses between the sealing surfaces and causing the bonding means to stretch along the pressed outermost sealing surface. The glass reflector exerts a shape on the glass lens in the opposite direction.

Sealing and stress problems found in automotive headlights due to the different shrinkage rates of the lens and reflector materials and intermediate adhesive means are common in parabolic aluminized reflector (PAR) lamps and elliptical reflector (ER) lamps.
) Also exists in lamps. Additionally, sealing problems in parabolic aluminized reflector lamps and elliptical reflector lamps are limited by the headlight operating temperature (approximately 120'
C) compared to these higher operating temperatures (approximately 140°C ~
150° C.) doubles and causes degradation of most adhesives that have low resistance to high temperatures. The adhesive means 15 of the invention, due to its properties of not decomposing at high operating temperatures of the lamp and being able to withstand high compressive stresses 114, somewhat relieves the stress between the sealing surfaces A, B, as a result of frequent changes in temperature. To provide a useful lamp for the environment.

The present invention significantly reduces thermally induced stresses by eliminating the flame seal, which is a method of creating a lens-to-reflector seal. Lens 12 and reflector 1
The adhesive means 15 used to bond 4 together must have a curing temperature equal to or higher than the operating temperature of lamp 10 and a higher coefficient of thermal expansion than the materials forming lens 12 and reflector 14.・No. lamp 10
The standard operating humidity for lamps such as
˜150° C., and the adhesive means used here provides a strong seal at this type of high temperature due to its own high curing temperature.

The material used to form the lens 12 and reflector 14 is typically hard glass, and the predetermined coefficient of thermal expansion of such material is approximately 40 x 10-7 cm2/°C. The adhesive means 15 of the present invention is about 148°C to 190°C.
with a curing temperature in the range of approximately 75 x 10-7 cm
Contains an epoxy resin having a coefficient of thermal expansion in the range of 2/°C to 3 ooxl 0-7 cm2/°C. The curing time of the epoxy resin is approximately 5 to 40 minutes. Epoxy resins currently in use are typically about 150 x 10-7 cI112
/°C (it) thermal expansion coefficient, a curing temperature of about 160°C, and a curing time of about 5 minutes. Adhesive means 15 can also include a UV-cured epoxy resin having similar expansion and temperature characteristics as the acceptable thermoset epoxy resins described above.

The epoxy resin used here has a higher coefficient of thermal expansion than the hard glass that forms the lens and reflector, so when the lamp is in an environment with a temperature lower than that at which the lens-to-reflector seal is cured, the lens-to-reflector seal can be cured. The compressive stress created around the inter-reflector seal provides a strong seal. This occurs during most, if not all, operating conditions as the lamp turns on and off. In addition, the lens 12 and the reflector 14
No special shape requirements for the sealing surfaces A, B are required by use of the sealing technique taught by the present invention. In one embodiment of the present invention, the lens sealing surface A has a groove-like or concave portion, and the reflector sealing surface B has a flange, so that the lens 12 and the reflector 14 are sealed together by the adhesive means 15. Sometimes a self-aligning relationship is formed (see Figure 2).

To assemble the lamp 10, the reflector 14 is first aluminized by applying a light reflective coating, typically comprised of aluminum or silver, to the inner surface 13 of the reflector 14. The reflector 14 is aluminized in such a manner as to provide an unaluminized area near the base of the reflector where the mating hole 22 is located. An eyelet 24 is then placed in the fit hole 22 and a mound of thermosetting epoxy resin 26 is injected around the eyelet 24. A washer 28 is placed near the eyelet 24 and secures the eyelet 24 from above. Capsule 16 is mounted to mounting member 20 and then inserted into fitting hole 22 and retained by the eyelet-epoxy-washer combination. The capsule-attachment assembly is then soldered thereto. An adhesive means 15, preferably a thermosetting epoxy resin, is applied to the lens 12, which is then adhered to the reflector 14 in a self-aligning manner. The lens-reflector assembly is then placed in a furnace for a period of time (approximately 5 to
40 minutes) and maintained at the required curing temperature (approximately 160° C.). The lamp 10 is then subjected to a brief nitrogen flush through the exhaust tube hole located in the reflector 14. The exhaust tube hole 34 is then plugged with a small steel ball bearing 35 and UV cured epoxy resin. The diode-fuse assembly and base 18 are then soldered.

As described above, an improved electrical lamp in which thermally induced distortion of the lens or reflector is significantly reduced or eliminated if the lens and reflector are bonded together, unlike traditional flame sealing methods. and a method for manufacturing a lamp of this type. The advantages of distortion-free parabolic aluminized reflector (PAR) lamps or elliptical reflector (ER) lamps are as follows.

High wattage tungsten-halogen capsules can be used without the additional heat generated causing strain failure.

There is no risk of thermal shock causing damage to the lamp envelope.
The lamp can be used more satisfactorily in harsh outdoor applications.

Breakage of the ambient air due to tungsten-halogen capsule breakage is virtually eliminated in junction beam lamps. The invention can be applied whenever a flame sealing method is used in a lamp to seal two corresponding and opposing parts together into a single part.

From the above description, it will be obvious to those skilled in the art that various applications and changes can be made without departing from the technical idea of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partial side view of an electric lamp according to the invention. FIG. 2 is a partial cross-sectional view of a lens-reflector seal according to the present invention. The names indicated by each number in the figure are listed below. Note that the same numbers do not indicate the same parts. 10: Lamp 11: Envelope 12: Lens 14: Reflector 16: Light source 18 Two bases 19: Lens-reflector seal 20: Mounting member 22: Fitting hole 24, eyelet 26 Niepoxy resin 28: Washer 30: Diode 32: Fuse wire 34: Exhaust hole tube 35: Ball bearing

Claims (14)

[Claims] (1) An envelope comprising a reflector and a lens made of substantially similar materials having a preset coefficient of thermal expansion; a light source disposed within the envelope and substantially surrounded by the reflector; and a gap between the lens and the reflector. adhesive means for sealing the lens and reflector together; A lamp characterized by having an expansion coefficient. (2) The lamp according to claim 1, wherein the reflector is an aluminized parabolic reflector. (3) The lamp according to claim 1, wherein the reflector is an elliptical reflector. (4) The adhesive means has a curing temperature in the range of about 148°C to 190°C, and has a curing temperature of about 75 x 10-7 cm^2/°C to 300 x
A lamp according to claim 1, comprising an epoxy resin having a coefficient of thermal expansion in the range 10^-^7 cm^2/°C. 5. The lamp of claim 4, wherein the epoxy resin has a curing time in the range of about 5 minutes to 40 minutes. 6. The lamp of claim 4, wherein the epoxy resin has a curing temperature of about 160 DEG C., a curing time of about 5 minutes, and a coefficient of thermal expansion of about 150.times.10.times.7 cm.sub.2/ DEG C. (7) The lens and reflector material is hard glass, and the preset thermal expansion coefficient is about 40 x 10^-^7cm
The lamp according to claim 5, which has a temperature of ^2/°C. (8) The lens and the reflector have a sealing surface disposed near their peripheries, the lens sealing surface includes a groove portion, and the reflector sealing surface includes a flange, so that the lens and reflector are bonded together by adhesive means. 2. A lamp as claimed in claim 1, which forms a self-aligning relationship when sealed together. (9) The light source includes a tungsten-halogen capsule mounted within a reflector, the reflector having a mating hole, and the tungsten-halogen capsule being mounted through the mating hole using an eyelet-washer epoxy resin combination. A lamp according to claim 1. (10) A method for manufacturing an electric lamp having an envelope formed of a lens and a reflector, the lens and the reflector having a sealing surface around the periphery, in which the reflector is treated with aluminum, a light source is mounted within the reflector, Adhesive means is arranged on the sealing surface of the lens, joining the lens sealing surface and the reflector sealing surface, and having a curing temperature equal to or higher than the operating temperature of the lamp and higher than the material forming the lens and reflector. The adhesive means having a coefficient of thermal expansion is heated to about 148°C to 190°C for a time of about 5 to 40 minutes.
A method of manufacturing a lamp comprising steps of curing to a temperature in the range of °C. (11) The method for manufacturing a lamp according to claim 10, wherein the reflector is a parabolic reflector. (12) The method for manufacturing a lamp according to claim 10, wherein the reflector is an elliptical reflector. (13) The adhesive means is approximately 75 x 10^-^7cm^2/
11. The method of manufacturing a lamp according to claim 10, comprising an epoxy resin having a coefficient of thermal expansion in the range of .degree. C. to 300.times.10.about.7 cm.sub.2/.degree. (14) Epoxy resin has a curing temperature of about 160°C and a
14. A method of manufacturing a lamp as claimed in claim 13, having a curing time of 10 minutes and a coefficient of thermal expansion of about 150 x 10^-^7 cm^2/°C.