JP7422980B2 - lamp - Google Patents

Description

The present invention relates to a lamp. More specifically, the invention relates to a lamp with a filament having a distinctive shape.

The present invention was completed in connection with a halogen lamp filament developed, produced, and sold by the applicant. Therefore, in this application, the embodiments will be explained using a halogen lamp as an example.

Halogen lamps are used as lighting lamps such as store downlights and automobile headlights, as well as for industrial heating, drying, baking, etc., and are used for semiconductor annealing, paint drying, etc. There is. A halogen lamp has a structure in which a filament is placed inside a cylindrical glass tube.

Common filament shapes include single coils (also called single-wound coils), which are made by coiling a single wire (meaning "wound"), and single coils (also called "single-wound coils"), which are made by coiling one wire. There are double-wound coils (also called "double-wound coils").

Furthermore, as disclosed in Patent Document 1, there is also a filament having a structure in which two wires are arranged in parallel and wound around a filament material serving as a core.

Patent No. 4470084 “Light bulb” (Issue date: 2010.06.02) Applicant: Kahoku Lighting Solutions Co., Ltd. JP 2002-270137 “Light bulb” (Publication date: 2002.09.20) Applicant: Philips Lighting Co., Ltd. JP 2005-32552 "Heater lamp for heat source" (Publication date: 2005.02.03) Applicant: USHIO INC.

When designing high-wattage halogen lamps, a double-coil filament shape is generally used. However, the higher the watt density of the filament, the thicker and larger the overall shape becomes. As a result, high watt density filaments tend to be easily deformed and have poor durability. Here, in this application, "watt density" refers to the wattage of the lamp per unit length along the helical axis of the filament winding (in the case of double winding, the helical axis after double winding) .

It is therefore an object of the present invention to provide a new high watt density filament with good electrical properties, shape retention and durability.
Furthermore, the present invention aims to provide a new lamp using a high watt density filament.

In view of the above object of the invention, the lamp filament according to the present invention is, in one aspect, a lamp filament that is bridged between electrodes and generates heat and emits light when energized, and the filament comprises two wires arranged side by side. It has a double coil shape, with a single coil filament wound twice.

Furthermore, the filament of the lamp may be formed by dividing the entire length into several blocks and reversing the winding direction multiple times.

Furthermore, the filament of the lamp may have a coil diameter that gradually changes along the helical axis.

In one aspect, the lamp according to the present invention includes a U-shaped bulb formed from a quartz glass tube filled with a trace amount of a halogen group element gas in addition to an inert gas, and two external leads. The device includes two internal leads connected to each other, and a filament connected to bridge the two internal leads, and the filament is any one of the above filaments.

Furthermore, the lamp may be a halogen lamp.

Furthermore, in the above lamp, the U-shaped bulb may be formed of a cylindrical main body and a flat leg, and a heat shielding film may be formed on the bulb peripheral surface transitioning from the main body to the leg. good.

Furthermore, in the lamp, the two legs of the U-shaped bulb include a cylindrical body and a flat leg, and an internal lead passing through the body. A heat shielding plate that substantially closes the main body portion may be disposed in the middle in the length direction.

According to the present invention, a novel high watt density filament with good electrical properties, shape retention, and durability can be provided.

Additionally, the present invention provides a novel lamp using a high watt density filament.

FIG. 1A is a cross-sectional view of the U-shaped halogen lamp according to the present embodiment taken along the lamp axis. FIG. 1B is a plan view of the halogen lamp shown in FIG. 1A, and is a diagram illustrating the shape of the filament. FIG. 2A is a diagram illustrating a conventional single-wound coil (single coil) filament. FIG. 2B is a diagram illustrating a filament of a coil (double coil) obtained by further winding the " single-wound coil shown in FIG. 2A" twice. FIG. 3A is a diagram illustrating a filament of a coil (single coil ) in which two wires are arranged side by side and wound in a single layer. FIG. 3B is a filament employed in this embodiment, and is a diagram illustrating a filament of a coil (double coil) obtained by further winding the " single-wound coil in which two wires shown in FIG. 3A are arranged side by side" twice. FIG. 4A is a side view of the lamp of FIG. 1A. FIG. 4B is an enlarged view of the section AA in FIG. 4A. FIG. 5 is a diagram illustrating a first modification of the filament shown in FIG. 3B. FIG. 6A is a diagram illustrating a second modification of the filament shown in FIG. 3B. FIG. 6B is a diagram illustrating a third modification of the filament shown in FIG. 3B.

Embodiments of the lamp according to the present invention will be described in detail with reference to the accompanying drawings. Here, the same elements are given the same reference numerals and redundant explanations will be omitted.
[First embodiment]
(Halogen lamp)
FIG. 1A is a cross-sectional view of a U-shaped halogen lamp 10 according to the present embodiment taken along the lamp axis. FIG. 1B is a plan view of the halogen lamp shown in FIG. 1A, and is a diagram illustrating the shape of the filament. In FIG. 1A, the numbers in italics indicate the dimensions (unit: mm) of each part of the lamp. The halogen lamp 10 includes a bulb 2 made of a quartz glass tube, which is filled with an inert gas and a trace amount of a gas containing a halogen group element (I, Br, CI, F). Note that this type of halogen lamp 10 is used with the illustrated lamp turned upside down.

The valve 2 is formed from a cylindrical main body 2c and flat sealed legs 2a, 2b (see also FIG. 4A). The diagonally shaded areas from the main body 2c to the flat legs 2a, 2b are areas where heat shielding films 5a, 5b are applied to prevent the heat of the filament 3a from transferring to the terminal 12 and damaging it. The chip 14 of the valve 2 is a trace of the internal degassing intake pipe.

A filament 3a is connected inside the bulb 2 so as to bridge two internal leads 4a, 4b. Although the filament 3a is depicted as a block in FIG. 1A for ease of viewing, it actually has a filament shape as shown in FIG. 1B. Internal leads 4a, 4b are connected to external leads 12a, 12b via molybdenum foils 8a, 8b within seal portions 6a, 6b, respectively. When the lamp is lit, power is supplied from the external leads 12a and 12b, and the filament 3a emits light and generates heat.

Filament 3a is typically made of tungsten. However, it is not limited to this. The shape of the filament 3a will be explained later in connection with FIGS. 2A to 3B. One of the features of this embodiment relates to the shape of the filament. It should therefore be appreciated that the scope of this embodiment extends to all lamps with a novel shaped filament bridged between electrodes that emits light and generates heat when energized.

The specifications of the halogen lamp shown in FIG. 1A are as follows.

Valve shape: U-shaped Valve material: Quartz glass tube Tube diameter: φ13mm
Dimension of parallel part to workpiece: 50mm
Dimension of vertical part to workpiece: 50mm (glass part only)
Filament length: 35mm
Rated power: 1300W
Lighting position: 180° rotated as shown in Figure 1

(shape of filament)
The shape of the filament, which is one of the features of this embodiment, will be explained with reference to the shape of a conventional filament.
FIG. 2A is a diagram illustrating a conventional single coil filament 300a. It is formed by winding one wire in one direction around a mandrel (core rod: not shown). The filament 300a removed from the mandrel is annealed to prevent springback. Each portion of the helical filament 300a is separated from an adjacent portion that has made one turn and is not in contact with it. This is because when the filaments come into contact and a short circuit current flows, the substantial length of the filament becomes shorter and the light emitting and heat generating effects are reduced.

FIG. 2B is a diagram illustrating a conventional double-coil filament 300b in which the single-wound coil filament 300a shown in FIG . 2A is further wound twice. Filament 300b is a double wrap of filament 300a to increase the watt density of the filament. The filament 300b is formed by winding the single-coil filament 300a around a mandrel in one direction. The filament 300b removed from the mandrel is annealed to prevent springback. Although not clearly shown in the figure, each portion of the helical filament 300b is separated from and does not contact the adjacent portion that has made one turn.

Generally, in order to further increase the watt density of the filament 300b, it is possible to wind the filament 23a in three layers. However, with triple-wound filaments, the filament itself becomes thick and large, making it difficult to maintain its shape, and it is difficult to maintain good electrical characteristics by separating each part of the filament from adjacent parts. With ordinary filaments, double winding is the limit unless special measures are taken.

FIG. 3A is a diagram illustrating a filament of a coil (single coil) in which two wires are arranged side by side and wound in a single layer . The filament 300c is formed by placing two wires side by side. Even if adjacent portions of two wires should come into contact, the substantial length of the filament remains unchanged and no short circuit occurs. Filament 300c may be identical to filament 300a of FIG. 2A with respect to filament winding.

Now, considering the novel halogen lamp 10 shown in FIG. 1A, a watt density of approximately 37 W/mm is required. In order to meet this required watt density, we first attempted a design with a double coil filament 300b type. However, since the outer diameter of the entire filament becomes large, there is a risk that the filament may come close to or come into contact with the bulb tube wall, and there was a concern that the bulb would expand during lighting.

Therefore, we considered making the " filament 300c of the coil, which is a single-wound coil of two wires arranged side by side as shown in FIG. 3A, " further double-wound . As a result of double winding a coil with two wires arranged side by side , the outer diameter of the filament was reduced, making it possible to secure a distance from the bulb and suppressing the high temperature of the bulb tube wall.

FIG. 3B is a diagram illustrating a filament employed in this embodiment, which is a coil filament (double coil) obtained by further winding the "single-wound coil in which two wires shown in FIG. 3A are arranged side by side" twice. That is, the filament 3a of FIG. 3A has a higher watt density. Since the filament 3a can be regarded as the same as the filament 300c in terms of filament winding, even if the filament is double-wound, no problems arise in terms of electrical characteristics, shape maintenance, and durability.

Note that the annealing process to prevent springback is performed when winding the wire around the mandrel by applying electricity to the wire to generate heat and then winding the wire. After winding, the electricity is turned off and the wire is cooled down or returned to room temperature before being removed from the mandrel. You may also remove it. Alternatively, the annealing treatment may be performed after the filament 3a is removed from the mandrel, as in the conventional manner.

For example, the specifications of an example in which this filament 3a is used in the halogen lamp 10 shown in FIG. 1 are as follows.
Filament material: Tungsten Single wire diameter: φ 0.149
Double coiled coil diameter: φ6
Watt density: 37 W/mm

At the prototype stage, compared to the 1,100 W lamp that uses the conventional double-coil filament 300b, the lamp that uses the high watt density filament 3a according to this embodiment has a parallel-wound double coil 3a, which produces 1,300 W. I was able to realize the lamp. In other words, the lamp output could be increased by 200 W. Furthermore, this parallel-wound double coil was able to reduce the coil outer diameter by about 1 mm compared to the conventional double coil 300b.

However, with the filament 3a having such a watt density (approximately 37 W/mm), the heat generated by the filament may be transmitted to the lead terminal 12 and damage the terminal 12. Therefore, it is necessary to take measures against the heat generated by the filament. Measures against heat generation will be explained in the third embodiment.

[Second embodiment]
In order to reduce the heat generated by the filament 3a shown in FIG. 1 from being transmitted to the lead terminal 12, the following two measures are adopted.

(1) Heat shield film formed on the outer peripheral surface of the bulb:
The diagonally shaded area shown in FIG. 1A is the heat shielding film 5. The heat shielding films 5a and 5b are formed by applying, for example, a mixture of alumina as a main component and silica to the outer peripheral surface of the bulb 2. This is adopted in order to prevent the radiant heat of the filament of the bulb body portion 2c from being conducted to the bulb leg portion 2b.

(2) Heat shield plate FIG. 4A is a side view of the lamp of FIG. 1A, and FIG. 4B is an enlarged view of the AA section of FIG. 4A. As shown in FIG. 4A, a heat shielding plate 24 is installed between the support rings 22a and 22b in the middle of the internal leads 4a and 4b so as to substantially close the main body in the middle of the valve body 2c in the length direction. is interposed. The support rings 22a, 22b were originally installed to pull the filament into place and to prevent the non-luminous wire (internal lead wire) to which the ring is attached from bending. In this embodiment, by utilizing the support rings 22a, 22b and arranging the heat shield plate 24 processed into a circular shape, an effect of reducing heat conduction via the internal leads 4a, 4b was observed. The heat shield plate 24 is made of tungsten, for example.

[Third embodiment]
There are the following modifications regarding the shape of the filament 3a.
Here, in order to simplify the diagram and make it easier to understand, the shape of the deformed filament will be explained by replacing the entire filament 300c shown in FIG. 3A with one thick line, as shown in the upper diagram of FIG.
As shown in the lower diagram of FIG. 5, the filament 3b of the first modification is a filament whose winding direction is reversed halfway through the filament. The filament 3b is wound clockwise from one end S to the center M, and counterclockwise from the center M to the other end E.

The filament 3b is annealed, but even if the ends of the coil are slightly deformed and moved in the circumferential direction due to springback when the lamp is repeatedly turned on and off, the circumferences of the right and left halves will remain the same. This has the effect that the directions of movement are canceled out, and the stress applied to the connection portion to the internal lead is reduced.
Although FIG. 5 shows an example in which the winding direction is reversed at the center M, the present invention is not limited to this. The entire length of the filament 3b may be divided into several blocks, and the winding direction may be reversed multiple times.

As shown in FIG. 6A, the filament 3c of the second modification is a filament in which the coil diameter gradually increases from one end S to the other end E. By winding the coil using a (cone-shaped) mandrel (not shown) that gradually tapers from the base to the tip, the coil diameter can be adjusted from one end to the other. A filament 3e is formed, which gradually increases in size.

As shown in FIG. 6B, the filament 3d of the third modification is a diagram illustrating a filament in which the coil diameter is gradually reduced from the left and right ends to the center. By separately winding the left and right coils from the center using a conical mandrel, a filament 3d whose coil diameter gradually decreases toward the center is formed.

Although not shown in the figure, when forming a filament whose coil diameter gradually increases from the left and right ends S and E to the center M, if the mandrel is made of metal, it is possible to remove the mandrel after winding the coil. Can not. In this case, the mandrel is made of a material that can be removed after winding. For example, a filament may be formed by using a hard wood or the like as a mandrel and burning the mandrel after winding the coil to remove residual charcoal. The mandrel may be formed of a thermoplastic resin and removed by heating and melting after winding the filament. Alternatively, the mandrel may be formed of ice and melted after winding.

In general terms, the filament 3c in FIG. 6A and the filament 3d in FIG. 6B are filaments having a shape in which the coil diameter gradually changes along the helical axis.

[summary]
Although the present embodiment of the lamp according to the present invention has been described above, these are merely examples, and the present invention is not limited thereto. The scope of the invention is defined by the claims appended hereto.

2: Bulb, quartz glass tube, 2c: Valve body, 2a, 2b: Valve leg, 3a, 3b, 3c, 3d, 300a, 300b, 300c: Filament, 4a, 4b: Internal lead, 5a, 5b: Shield Heat film, 6a, 6b: Seal part, 8a, 8b: Molybdenum foil, 12a, 12b: External lead, lead terminal, 14: Chip, 16, 22a, 22b: Support ring, 24: Heat shielding plate

Claims (6)

A U-shaped bulb formed from a quartz glass tube, which is filled with a trace amount of gas consisting of a halogen group element in addition to an inert gas;
two internal leads connected to two external leads, respectively;
and a filament connected to bridge the two internal leads,
The filament is a lamp filament that generates heat and emits light when energized , and is in the shape of a single-wound coil in which two wires each made of tungsten are arranged side by side, and then further wound twice. The lamp according to claim 1,
The lamp is formed by dividing the entire length of the filament into several blocks and reversing the winding direction multiple times. The lamp according to claim 1,
The filament is a lamp in which the coil diameter gradually changes along the helical axis. The lamp according to claim 1 ,
The lamp is a halogen lamp. The lamp according to claim 1 ,
The U-shaped bulb is formed of a cylindrical main body and a flat leg, and a heat shielding film is formed on the circumferential surface of the bulb that transitions from the main body to the leg. The lamp according to claim 1 ,
The U-shaped valve is formed of a cylindrical main body and a flat leg, and a heat shield plate is disposed midway along the length of an internal lead passing through the main body to substantially block the main body. A lamp.

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