JPH0626149U - Heat resistant light bulb - Google Patents

Abstract

(57) [Summary] [Structure] The glass sphere (2) and the connector type base (3) are joined by a ceramic adhesive (4), and the adhesive applied inside the base and the glass sphere are bonded. A heat-resistant sheet-shaped cushioning material (1) was interposed between the surfaces. [Effect] Even if it is continuously used in a high temperature atmosphere, the glass sphere does not crack. In addition, the adhesive portion between the glass ball and the base does not peel off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a small heat-resistant light bulb for internal lighting, which is used in a high-temperature atmosphere of an oven or a microwave oven having an oven function.

[0002]

[Prior art]

 Generally, a phenolic adhesive is used to bond the glass bulb of the light bulb to the base, but when it is used in an atmosphere of 180 ° C or higher for a long time, the adhesive carbonizes and peels off the joint. Therefore, it is not suitable as a light bulb for internal lighting such as an oven. On the other hand, as a heat-resistant light bulb, there is a method of pressing a glass ball into the base without using an adhesive or a mechanical method of screwing a glass ball into the base and molding a sealing part at the boundary, but the press-fitting part is used. However, not only will the cost be high due to the need for a special base due to the molding of the sealing part and its method, but the heat-resistant light bulb for internal lighting such as an oven has a small glass bulb with a diameter of 30 mm or less. Not used because the distance between the side surface that will be the electrode and the electrode formed on the bottom is less than the distance specified by the safety standards under the Electrical Appliance and Material Control Law.

[0003]

[Problems to be solved by the device]

 Therefore, if the glass ball and the connector type base are bonded with a ceramic adhesive, it can be used in a high temperature atmosphere of 180 ° C or higher, but if it is continuously used in a high temperature atmosphere of 300 ° C or so. During the cooling process, cracks may occur around the glass sphere (the part indicated by the alternate long and short dash line (a) in Fig. 1). It is speculated that this is caused by the glass sphere being pressed by the shrinking force when the thermally expanded adhesive returns to room temperature after use. When such a crack occurs, it may not be possible to maintain the function as a light bulb.

[0004]

[Means for Solving the Problems]

 Therefore, in order to enable use in a high temperature atmosphere, the present invention prevents the peeling by joining the glass ball and the connector type base with a ceramic adhesive, and the adhesive applied inside the base. By interposing a heat-resistant sheet-shaped cushioning material between the bonding surfaces of the glass sphere and the glass sphere, we succeeded in preventing the occurrence of cracks.

[0005]

[Action]

 By using a ceramic adhesive, it can be used in a high temperature atmosphere, and the shrinking force of the adhesive when returning to room temperature is relaxed by the cushioning material when using it. There will be no cracks.

[0006]

【Example】

 1 and 2 are explanatory views of a heat-resistant light bulb according to the present invention. (1) is a cushioning material, (2) is a glass ball, (3) is a connector type base, and (4) is a ceramic adhesive. The cushioning material (1) is a glass fiber cloth having a thickness of 0.1 to 0.3 mm and a width of about 10 mm, and is formed into a sheet shape as shown in FIG. 2. The center of the longitudinal direction is a glass ball as shown in FIG. It is located at the boundary when the glass is glued, and its hem (c) is attached to the peripheral surface of the glass bulb so as to intervene on the base side. That is, a cushioning material intervenes between the adhesive applied to the upper edge opening of the die and its periphery and the adhesive surface of the glass ball. The glass sphere is made of soda glass with a diameter of about 25 mm and contains a gas containing krypton as its main component. (5) is a filament, (6) is an anchor, (7) is a lead wire, (8) is a stem, (9) is an electrode pin, and (10) is an insulating plate for insulating the electrode pin and the base. . Further, as shown in FIG. 2, it is connected to a connector (13) through a lead wire (12) protected by a glass tube (11). Then, as shown in FIG. 3, they are housed in a case (14) provided on the upper surface of the oven (15) and are used for lighting the cooked food.

When cooking is started and the temperature of the atmosphere in the oven reaches 300 ° C., the adhesive begins to expand, but since the adhesive is a ceramic type, it does not carbonize. Next, when cooking is completed, the thermally expanded adhesive begins to shrink, but the elasticity of the cushioning material (1) does not press the glass sphere, and cracks may occur near the boundary with the die. Absent. According to an experiment conducted by the inventor, as shown in FIG. 1, the hem (c) of the cushioning material is about 1/2 of the bonding length (L) when the glass ball and the base are bonded to the base side. It has been proved that the shrinkage force of the adhesive can be relaxed most, cracks do not occur, and the adhesive force for practical use is maintained.

Rock wool or the like may be used as the cushioning material. Further, the shape, size, and attachment position of the cushioning material can be changed according to the shape, size, etc. of the glass ball or the die.

[0009]

[Effect of device]

 With the heat-resistant light bulb according to the present invention, even if it is continuously used in a high temperature atmosphere, the glass bulb does not crack. In addition, the adhesive portion between the glass ball and the base does not peel off. Therefore, stable use of the oven or the like can be continued.

[Brief description of drawings]

FIG. 1 is an explanatory view of a heat-resistant light bulb according to the present invention.

FIG. 2 is an explanatory view showing a step of attaching a cushioning material to the glass bulb of the heat-resistant electric bulb according to the present invention.

FIG. 3 is an explanatory view showing a heat-resistant electric bulb according to the present invention mounted in an oven.

[Explanation of symbols]

1 ・ ・ Cushioning material 2 ・ ・ Glass sphere 3 ・ ・ Flange 4 ・ ・ Adhesive 5 ・ ・ Filament 6 ・ ・ Anchor 7 ・ ・ Introduction wire 8 ・ ・ Stem 9 ・ ・ Electrode pin, 10 ... Insulating plate, 11 ... Glass tube, 12 ... Lead wire, 13 ... Connector, 14 ... Case, 15 ... Oven

Claims (1)

[Scope of utility model registration request] 1. A glass ball and a connector-type base are joined by a ceramic adhesive, and a heat-resistant sheet-shaped cushioning material is interposed between the adhesive applied to the base and the bonding surface of the glass ball. A heat-resistant light bulb characterized by that.