JP3118749B2 - Double tube incandescent bulb - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-tube incandescent lamp for general lighting.

[0002]

2. Description of the Related Art Conventionally, as an incandescent lamp used for general lighting in offices and stores, a double-tube incandescent lamp in which an incandescent lamp is covered with an outer tube to form a double tube is used from the viewpoint of safety. Often. And in such a double tube type incandescent lamp, the incandescent lamp built in the inside has many structures sealed by the outer tube. Such a double-tube incandescent lamp is disclosed in Japanese Utility Model Publication No. 4-54683 and Japanese Utility Model Publication No. 5-1648.

[0003]

However, in a conventional double-tube incandescent lamp which is sealed by an outer tube as in the prior art, if the incandescent lamp is damaged during operation, the scattered bulb and the incandescent lamp may be used. When the high-pressure gas sealed in the valve is rapidly released into the outer tube, an impact is applied to the outer tube and the outer tube may be damaged.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a double-tube incandescent lamp with high safety.

[0005]

In order to solve the above-mentioned problems, a double-tube incandescent lamp according to claim 1 is provided with a pair of externally extending externally extending airtightly through a crimp sealing portion at one end. An incandescent lamp having a lead rod, a base for holding the incandescent lamp, and a double-tube incandescent lamp having an outer tube attached to the base so as to surround the incandescent lamp; The total pressure is 1.5 atm (25-reference) or less, and the outer tube has a thickness of 2.0 mm or more;
The space between the top inner surface of the outer tube and the top outer surface of the incandescent lamp
And a buffer member is provided. Claim
The double-tube incandescent lamp according to item 2 is the dual-tube incandescent lamp according to item 1.
A double-tube incandescent light bulb, in particular, the buffer member is heat-resistant.
It is made of glass fiber having flexibility and flexibility.
Sign.

[0006] The filling gas of the incandescent lamp is a mixed gas of a rare gas such as argon or krypton and an inert gas such as nitrogen. The mixed gas is sealed at a total pressure of noble gas and inert gas of 1.5 atmospheres or less (based on 25 ° C.).

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

[0014]

The double-tube incandescent lamp according to the first aspect has an incandescent lamp having a pair of external lead rods extending airtightly through a crimp sealing portion at one end and holding the incandescent lamp. And an outer tube for surrounding the incandescent lamp is attached to the base. Since the total pressure of the filled gas of the incandescent lamp is 1.5 atm (25 reference) or less, if the incandescent lamp is damaged, the force of the bulb scattered and the force of the filled gas released into the outer tube are reduced to a certain level or less. And the outer tube has a thickness of 2.0 mm or more,
Since the outer tube is strong, it will not be damaged ,
A buffer between the inner surface of the top of the outer tube and the outer surface of the top of the incandescent lamp
Is filled, so that even if the incandescent bulb
Shards are weaker than the trunk in the outer tube.
Direct collision with the part can be prevented. Claim 2
Double-tube incandescent lamps have both heat resistance and flexibility as cushioning members.
Since the glass fiber is used,
The effect of increases.

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A double tube incandescent lamp of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a double-tube incandescent lamp of the present invention. The double-tube incandescent lamp includes an incandescent lamp 1 having a filament disposed along the axis of the tube, a base 2 for holding the incandescent lamp 1, and an externally arranged base 2 surrounding the incandescent lamp 1. Tube 3 is attached.
The inner surface of the outer tube 3 is indicated by a dotted line for convenience.
Are formed. When the outer tube 3 is broken, the silicone coating M is used to stop countless pieces of the outer tube 3 and prevent the pieces of the outer tube 3 from scattering. A cushioning member K is filled between the inner surface of the top of the outer tube 3 and the outer surface of the top of the incandescent lamp 1. This buffer member K is made of glass fiber having heat resistance and flexibility.
It is.

In the incandescent lamp 1, as shown in FIG. 2, one end of a bulb 11 is a flat crimp sealing portion 12, and a molybdenum foil 13 is crimp sealed. A filament 14 formed by winding a tungsten wire around a dense coil is arranged in the bulb 11 along the tube axis of the bulb 11. Both ends of the filament 14 are connected to an internal lead rod 15 made of molybdenum, and the ends of the internal lead rod 15 are welded to the molybdenum foil 13, respectively. Then, the pair of external lead rods 16 is also made of the molybdenum foil 13.
, And extends outward from the crimp sealing portion 12,
Each is connected to a lead wire 17 and a fuse wire 18.

The base 2 is made of ceramic, and as shown in FIG.
A small-diameter fixing portion 23 provided on one side surface 22 and a conical mounting portion 24 provided on the opposite side of the one side surface 22 of the flange portion 21. In addition, the flange part 21, the fixing part 23, and the mounting part 24 are integrally formed. The fixing portion 23 is bifurcated so as to receive the flat crimp-sealing portion 12 of the incandescent lamp 1.
The notch 26 is formed in the opposing surface which faces the press-fit sealing part 12 of FIG. Then, the forked gap 2 of the fixing portion 23
5 is inserted with the pressure-sealing portion 12 and fixed with an adhesive. At this time, when the adhesive flows into the notch 26 of the fixing portion 23 and solidifies, the notch 26 and the adhesive are in a strong fitting state, so that the press-fit sealing portion 12 and the fixing portion 23 are firmly fixed. . Further, the fixing portion 23 has a cutout portion 27 formed on a surface facing the outer tube. Outer tube 3
The opening end is in contact with one side surface 22 of the flange portion 21 and is fixed to the fixing portion 23 by an adhesive. At this time, when the adhesive flows into the notch 27 of the fixing part 23 and solidifies, the notch 27 and the adhesive are in a strong fitting state, so that the outer tube 3 and the fixing part 23 are firmly fixed. In addition, it helps to prevent the outer tube 2 from rotating.

The mounting portion 24 has a conical shape, and has an electrical contact portion 4 electrically connected to a lead wire 17 connected to the external lead rod 16 of the incandescent lamp 1 at its tip. A metal base 5 having a spiral groove is formed on the outer peripheral surface of the mounting portion 24. The base 5 is brazed and electrically connected to the fuse wire 18 connected to the external lead rod 16 of the incandescent lamp 1.

The flange portion 21 has an outer surface portion 28 formed by removing a part of a circular outer peripheral surface. The outer surface portion 28 is flattened by removing an outer portion of a cut line (that is, a chord) parallel to the diameter of the circular portion of the flange portion 21. Although the outer surface portion 28 is flat in this embodiment, it may be arc-shaped or the like, and as will be described later, in short, the open end of the outer tube 3 is
When it is fixed to the fixing portion 23 by the adhesive with the abutment, it is sufficient that a gap exists between the outer surface portion 28 and the opening end of the outer tube 3.

The base 2 has a hole formed at the center thereof, which is connected to the top of the conical mounting portion, but is omitted in the drawings. The external lead rod 16 of the incandescent lamp 1 and the lead wire 17 and the fuse wire 18 connected thereto are inserted into this hole.

FIG. 4 is an explanatory diagram of the outer tube. The outer tube 3
A convex portion 32 is formed on the inner surface facing the fixing portion 23 shown in FIG. In this embodiment, the convex portion 32 is formed by embedding a silicone resin. However, when the outer tube 3 is manufactured, the convex portion may be integrally formed. In short, it is only necessary that at least one convex portion exists on the inner surface of the outer tube facing the fixing portion. The outer tube 3 has its open end 31 in contact with one side surface 22 of the flange portion 21 shown in FIG. 3 and is fixed to the fixing portion 23 by an adhesive. Then, when the adhesive is solidified, the adhesive and the convex portion 32 are in a fitted state, so that the adhesive strength between the base 2 and the outer tube 3 can be increased. Then, even if the incandescent lamp 1 is damaged and fragments of the bulb 11 of the incandescent lamp 1 are scattered, or if the sealed gas sealed in the bulb 11 is rapidly released into the outer tube 3, the outer tube 3 is not damaged. No more than 2 drops.

FIG. 5 is a perspective view of the double-tube incandescent lamp of the present invention as viewed from the direction of the mounting portion. The outer tube 3 is fixed to the base 3 by an adhesive with its open end 31 in contact with one side surface 22 of the flange portion 21. A gap G is formed between the outer surface 28 of the flange 21 and the open end 31 of the outer tube 3. Since the gap G communicates with the inside of the outer tube 3, if the incandescent lamp 1 is broken, even if the sealed gas in the bulb 11 is rapidly discharged into the outer tube 3,
The released gas can escape to the outside through the gap G. Therefore, even if the incandescent lamp 1 is damaged, the outer tube 3 can be prevented from being damaged.

As shown in FIG. 1, a cushioning member K is filled between the inner surface of the top of the outer tube 3 and the outer surface of the top of the incandescent lamp 1. Since the top of the outer tube 3 is processed into a spherical shape, the wall thickness is slightly smaller than other portions of the outer tube, and the top portion of the outer tube 3 is processed into a spherical shape, so that the distortion at the top is completely removed. If the incandescent lamp 1 is damaged, the outer tube 3 may be damaged if the fragments of the bulb 11 directly collide with the inner surface of the top of the outer tube 3. Therefore, even if the incandescent lamp 1 is damaged by filling the buffer member K into the space between the top inner surface of the outer tube 3 and the top outer surface of the incandescent lamp 1,
The fragments of the valve 11 can be prevented from directly colliding with the inner surface of the top of the outer tube 3 by the cushioning member K.

Next, a double-tube incandescent lamp according to the present invention,
A description will be given of a breakage experiment performed by actually manufacturing a double-tube incandescent lamp for comparison. The present invention and comparative double-tube incandescent lamps (hereinafter, referred to as lamps) were manufactured according to the following specifications. (1) Outer tube material: hard glass (borosilicate glass) (2) Outer tube outer diameter: 18 mm (3) Outer tube wall thickness: 1.0 to 1.0 3.0 mm (4) Outer diameter of incandescent lamp: 11 mm (5) Filled gas: Rare gas and inert gas (6) Total pressure of filled gas: 0.5 to 2.5 Atmospheric pressure (25
(7 ° C) (7) Lamp voltage ... 110 V (8) Lamp current ... 0.77 A (9) Power consumption ... 85 W The wall thickness of the pipe and the total pressure of the filled gas in (6) were combined in the above range for each of the five types, for a total of 25
Twenty lamps of each type were manufactured. The method of the experiment is as follows. After lighting under the same lighting conditions of each lamp (voltage 110 V, current 0.77 A), apply an overvoltage (approximately 2000 V) to both ends of the power supply unit to forcibly turn on the incandescent lamp. The tube was damaged and the outer tube was checked for damage.

FIG. 6 shows the results. Each of the 20 pieces was manufactured, and the number of pieces damaged was described. The damage of the lamp in this experiment refers to the situation where the outer tube is damaged. The following facts were found from the experimental result data explanatory diagram of FIG. (A) In the case of a lamp having an outer tube thickness of 1.0 mm, the lamp was broken regardless of the charged gas pressure. More specifically, when the filling gas was 0.5 atm, 1.0 atm, and 1.5 atm, three to four out of twenty tubes were damaged, respectively. Furthermore, when the sealed gas was 2.0 atm and 2.5 atm, 8 to 11 out of 20 tubes were damaged, respectively. That is, when the thickness of the outer tube was 1.0 mm, it was not possible to prevent the lamp from being damaged. (B) In the case of a lamp having an outer tube thickness of 1.5 mm, the lamp was not damaged when the filling gas was 0.5 atm or 1.0 atm. However, when the filling gas was 1.5 atm, 2.0 atm, and 2.5 atm, damage to the lamps could not be prevented, and 2 to 9 lamps out of 20 lamps were damaged. (C) In the case of the lamp having the outer tube thickness of 2.0 mm, the lamp was not damaged when the filling gas was 0.5 atm, 1.0 atm, and 1.5 atm. However, when the sealed gas was 2.0 atm and 2.5 atm, damage to the lamps could not be prevented, and 2 to 4 lamps out of 20 lamps were damaged. (D) In the case of a lamp having an outer tube thickness of 2.5 mm, the lamp is damaged when the filling gas is at least 2.0 atm, and when the outer tube thickness is 3.0 mm, the lamp is broken at a pressure of at least 2.5 atm. I understood that.

Based on the above experimental data, the charged gas pressure was set to 1.5
It was found that the combination should be less than atmospheric pressure and the outer tube thickness should be 2.0 mm or more. On the other hand, the lower limit of the filling gas pressure is preferably 0.8 atm or more in order to prevent early breakage of the filament. The outer wall thickness is preferably as thick as possible, but is preferably 3.5 mm or less in consideration of ease of use with an instrument, productivity and cost. As the material of the outer tube, hard glass (borosilicate glass) is used in this embodiment, but a quartz tube may be used.

[0032]

The double-tube incandescent lamp according to claim 1 is
The total pressure of the gas in the incandescent lamp is 1.5 atm (25 reference) or less
If the incandescent bulb is damaged, the bulb will splatter
Pressure and the force of the sealed gas released into the outer tube
1. The thickness of the outer tube can be reduced to 2.
0 mm or more.
And inside the top of the outer tube and outside the top of the incandescent lamp
Since the cushioning member is filled between the
If the valve breaks, the fragments of the valve will remain in the outer tube compared to the body
Low strength, can prevent direct collision with the top
You. The double-tube incandescent lamp according to claim 2 is used as a buffer member.
Uses glass fiber that has both heat resistance and flexibility
The effect is further increased.

[0033]

[0034]

[0035]

[0036]

[0037]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a double-tube incandescent lamp of the present invention.

FIG. 2 is an explanatory diagram of an incandescent lamp incorporated in the double-tube incandescent lamp of the present invention.

FIG. 3 is an explanatory view of a base of the double-tube incandescent lamp of the present invention.

FIG. 4 is an explanatory view of an outer tube of the double-tube incandescent lamp of the present invention.

FIG. 5 is a perspective view of the double-tube incandescent lamp of the present invention as viewed from the direction of the mounting portion.

FIG. 6 is an experimental result data regarding the damage of a double-tube incandescent lamp.
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Incandescent lamp 11 Bulb 12 Crimp sealing part 13 Molybdenum foil 14 Filament 15 Internal lead rod 16 External lead rod 2 Base 21 Flange part 22 One side of flange part 23 Fixed part 24 Mounting part 25 Gap 26 Notch 27 Notch 28 Outer surface part 3 Outer tube 31 Open end 32 Convex part 4 Electrical contact part 5 Base M Silicone coating G Void K Buffer member

Continuation of the front page (56) References JP-A-7-347059 (JP, A) JP-A-6-260150 (JP, A) JP-A-6-251756 (JP, A) JP-A-7-226191 (JP) JP-A-6-310109 (JP, A) JP-A-7-73854 (JP, A) JP-A-2-97748 (JP, U) Japanese Translation of PCT Application No. Sho 61-500391 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01K 1/34 H01K 1/32

Claims (2)

(57) [Claims] 1. An incandescent lamp having a pair of external lead rods extending airtightly through one end of a compression sealing portion at one end, a base for holding the incandescent lamp, and the incandescent lamp mounted on the base. In a double-tube incandescent lamp in which an outer tube is attached so as to surround the incandescent lamp, the total pressure of the gas filled in the incandescent lamp is 1.5 atm (25 reference) or less, and the outer tube has a thickness of 2. 0 mm or more, and the space between the top inner surface of the outer tube and the top outer surface of the incandescent lamp
Characterized in that a buffer member is disposed on the double pipe
Incandescent light bulb. 2. The cushioning member has heat resistance and flexibility.
The double tube type according to claim 1, comprising a glass fiber.
Incandescent light bulb.