JP3074196U - Lamp housing for image projection equipment - Google Patents

Abstract

An object of the present invention is to prevent an explosion-proof glass plate, which incorporates a lamp, which is an illumination light source of an image projection device, from locking an explosion-proof glass plate on a front surface of a lamp housing. SOLUTION: The explosion-proof glass plate and the lamp housing main body are heated and expanded by the heat generated by the lighting of the lamp. The difference in the speed and the amount of expansion and contraction causes the peeling of the bonding interface in the case of the adhesive locking, and the displacement of the packing in the press-fitting and the locking via the packing. The locking strength may be reduced or the explosion-proof glass plate may fall off. According to the present invention, a groove is provided on the entire periphery of the outer peripheral end face of the explosion-proof glass plate or a part thereof, and if necessary, the inner periphery of the locking portion of the explosion-proof glass plate of the lamp housing body has a reverse tapered structure or a groove is provided. The tapered portion was filled with the adhesive or the packing was bitten, and the anchoring effect was exerted to prevent a decrease in the locking strength.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a lamp housing as an image light source of an image projection device such as an overhead projector and a liquid crystal projector.

[0002]

[Prior art]

 An explosion-proof glass plate having an end surface perpendicular to the flat surface is fixed to the front surface of the lamp housing, which has a reflector effect by attaching a reflective coating film, which is the image light source of the image projection device, with an adhesive lock or press-fit with a packing. I was

[0003]

[Problems to be solved by the invention]

 As image light sources for image projection equipment are required to be brighter and smaller, the heat generated by the use of high-power metal halide lamps, xenon lamps, ultra-high pressure mercury lamps, etc. The amount has increased. For this reason, the temperature of the lamp housing at the time of lamp lighting may exceed 200 ° C, and this may be caused by the difference in the thermal expansion coefficient between the lamp housing body and the explosion-proof glass plate attached to the front of the lamp and the difference in the heating rate. The adhesive or packing used for locking loosened and the locking strength was lost, causing the explosion-proof glass plate to fall off at a rate of about 0.1% in the image projection equipment in use. The present invention is intended to eliminate the accident of the explosion-proof glass plate falling off.

[0004]

[Means for Solving the Problems]

 The present invention was obtained based on a detailed observation of the lamp housing of the image projection device in which the explosion-proof glass plate fell off. That is, in the case of adhesive locking, the boundary surface between the adhesive and the explosion-proof glass plate peeled off, and in the case of press-fitting locking via packing, the position of the packing fluctuated and the compression force did not work effectively. The explosion-proof glass plate has fallen from the lamp housing.

In view of the cause of the drop, a groove is provided on the outer peripheral end surface of the explosion-proof glass plate, that is, an adhesive surface for locking with the lamp housing, or a position for locking via a packing. Explosion-proof glass plates no longer fall off. Furthermore, when a groove was provided on the inner periphery of the explosion-proof glass plate locking portion of the lamp housing main body or a reverse tapered structure was used, the locking strength was significantly improved.

[0006]

[Embodiment of the invention]

 Grooves as shown in (a), (b), and (c) of Fig. 2 are provided on the outer peripheral end surface of the explosion-proof glass plate. Epoxy resin, unsaturated polyester, ethylene glycol dimethacrylate, etc. are used as heavy and compact adhesives and high temperature resistant adhesives. After gluing to the housing using polyvinyl formal phenolic, nitrile epoxy, polybenzimidazole as the agent and ethyl silicate 40, alumina cement, super-early rising cement, or a mixture of lime and alginic acid as the ceramic adhesive, there is no groove. Along with the conventional product, it was left in an oven at 280 ° C. and 350 ° C. for 10 minutes and taken out.

[0007] Similarly, after a pure copper plate having a thickness of 0.1 mm and a width of 5 mm is press-fitted and locked to a conventional product having no groove in the explosion-proof glass plate and a grooved product of the present invention as a packing, the temperature is 280 ° C and 350 ° C, respectively. The sample was left in an oven at a temperature of 10 ° C. for 10 minutes and taken out. After cooling, the punching strength was measured.

Next, a groove or a reverse taper is provided on the entire inner periphery of the lamp housing or a part thereof, and the conventional explosion-proof glass plate and the grooved product of the present invention are bonded and locked, respectively, as described above. After press-fitting and locking the plate as a packing, the plate was left in an oven at 280 ° C. and 350 ° C. for 10 minutes, taken out, and the cooling strength after cooling was measured.

[0009]

Example 1 As a result, the pull-out strength of the adhesive-locked product was as follows: the non-grooved conventional product had a minimum of 0 kg and a maximum of 1.5 kg after being left in an oven at 280 ° C. and 350 ° C. for 10 minutes. The minimum weight was 5.5 kg, and the maximum weight was 10.0 kg. This strength is equivalent to the shear strength of the adhesive filling the groove of the explosion-proof glass plate.

As a result of this comparative measurement, the adhesive is dried and shrunk by high-temperature aeration, or the adhesive surface is peeled off due to the expansion and contraction of the bonding interface due to the difference in the thermal expansion coefficient between the lamp housing and the explosion-proof glass plate. However, it was confirmed that the locking between the lamp housing body and the explosion-proof glass plate maintained sufficient strength.

The results to be noted here are almost unaffected by the shape of the groove provided on the outer peripheral end face of the explosion-proof glass plate as shown in FIGS. 2 (a), 2 (b) and 2 (c). The locking strength corresponding to the shear strength of the above was exhibited.

From the above examples, it has been confirmed that any shape of the groove provided in the explosion-proof glass plate exerts the expected effect, so that the shape of the groove is not restricted to a specific shape in claim 1. .

[0013]

Example 2 After making the outer diameter of the explosion-proof glass plate slightly smaller, grooves were provided as shown in FIGS. 2 (a), (b) and (c), and a pure copper plate having a thickness of 0.1 mm and a width of 5 mm was used as a packing. The product which was press-fitted with a press-fitting strength of 8 kg was measured in comparison with a conventional product having no groove. As a result of measuring the pulling strength immediately after the press-fitting, the conventional product having no groove was in the range of 1.5 kg to 2.0 kg. On the other hand, those provided with the grooves weighed 2.5 kg to 4.0 kg.

[0014] Next, the product pressed and locked at 7 to 8 kg was left in an oven at 350 ° C for 10 minutes and taken out. After cooling and comparing and measuring the punching strength, the conventional product having no groove was 0.5 kg to 2. 0 kg, whereas the one provided with grooves was 2.5 kg to 4.0 kg, and no decrease in the punching strength due to high-temperature aeration was observed.

[0015]

Embodiment 3 In order to further increase the effect of the present invention, a groove is provided on the outer peripheral end face of the explosion-proof glass plate, and at the same time, an inverted tape as shown in FIG. Or by attaching a groove as shown in Fig. 3 (b) to bond and lock the explosion-proof glass plate, or press-fitting and locking through packing, leaving it in an oven at 350 ° C for 10 minutes, removing it, and cooling it. Thereafter, the punching strength was measured comparatively.

[0016] As a result, it showed 1.5 times the pullout strength as compared with the case where the groove was provided only in the explosion-proof glass plate. In particular, some of the ones that were adhesively locked with a ceramic adhesive and the ones that were press-fitted and locked with a pure copper plate as packing exhibited locking strength that did not come out until the explosion-proof glass plate was damaged.

[0017]

[Effect of the invention]

 If a groove is provided on the entire outer periphery of the explosion-proof glass plate or on a part of it, and it is adhesively locked to the lamp housing, or it is press-fitted and locked via packing, the adhesive or packing will bite into the groove and exhibit an anchoring effect. Therefore, even after high-temperature aeration, a decrease in the locking strength is small.

Further, it has been found that when an inverted taper is provided or a groove is provided on the entire inner circumference of the locking portion of the explosion-proof glass plate of the lamp housing body or a part thereof, a greater locking strength is maintained. . As a result, it was possible to prevent the explosion-proof glass plate from falling off even when the temperature of the lamp housing became high, by using the image projection device continuously for a long time. In addition, even if the locking points between the lamp housing body and the explosion-proof glass plate are limited to a small size due to the design requirements for a more compact video projection device, sufficient locking strength can be maintained. is there.

[Brief description of the drawings]

FIG. 1 is an assembled sectional view of a conventional lamp housing of an image projection device to which the present invention is applied.

FIG. 2 shows a shape of a groove provided on an outer peripheral end surface of an explosion-proof glass plate which is locked to a lamp housing according to an embodiment of the present invention.
(A) is a sectional view showing a square groove, (b) is a triangular groove, and (c) is a cross-sectional view showing a round groove.

FIGS. 3A and 3B are cross-sectional views illustrating an inverted tapered structure provided on the inner periphery of the explosion-proof glass plate locking portion of the lamp housing body according to the embodiment of the present invention, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp housing main body 2 Lamp 3 Explosion-proof glass plate 4 Adhesive or packing

Claims (2)

[Utility model registration claims] In a structure in which an explosion-proof glass plate is press-fitted and locked to the front surface of a lamp of a lamp housing via an adhesive or a packing, an explosion-proof glass plate having a groove formed on the entire outer peripheral end surface or a part thereof is provided. A lamp housing which is locked. 2. A structure in which an explosion-proof glass plate is press-fitted and locked to the front surface of a lamp of a lamp housing via an adhesive or a packing. A lamp housing, characterized in that a groove or a reverse taper is provided on the entire inner periphery or a part of the inner periphery of an explosion-proof glass plate locking portion of the lamp housing.