JPH0384845A - Method for forming polarity indicating portion of discharge tube - Google Patents

Abstract

PURPOSE:To form such a discharge tube that its polarities are easily recognized without increasing the number of manufacturing processes by forming the sandwiching faces of sandwiching portions into different shapes, and, on the sealing portion of a tubular bulb which corresponds to the sandwiching faces, processing into different shape the surface of the bulb near that portion where one lead wire is sealed, to form a polarity indicating portion. CONSTITUTION:After electrodes 3a, 3b connected to respective lead wires 5a, 5b being independent from each other are arranged in the inner space of a tubular bulb made of glass, one end of the tubular bulb is sandwiched in the direction roughly perpendicular to the axial direction of the lead wires 5a, 5b by a jig 7 provided with a pair of sandwiching portions 7c, 7d, so that a sealing portion is formed at one end of the tubular bulb. In this case, the sandwiching faces of the sandwiching portions 7c, 7d are made into different shapes so that on the sealing portion 4 of the tubular bulb which corresponds to the sandwiching faces the surface of the bulb near that portion where one lead wire 5a is sealed is processed into different shape to form a polarity indicating portion 6; during the sealing process, formation of the polarity indicating portion 6 is therefore enabled simultaneously with sealing treatment. Thus a discharge tube provided with the polarity indicating portion 6 is obtained without increasing the number of manufacturing processes.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for forming a polarity indicating portion in a discharge tube having an envelope made of a sealed glass bulb, and particularly relates to a method for forming a polarity indicating portion in a discharge tube having an envelope made of a sealed glass bulb. The present invention also relates to a technique that can reliably and extremely easily form a polarity display section by providing a polarity display section at the same time.

[Conventional technology]

Tube elements operated by a DC power source, such as neon lamps or other discharge tubes, are marked with a polarity mark to indicate whether the electrode terminal led out of the bulb is an anode or a cathode. It is known to apply.

FIG. 5 shows a discharge tube 1 according to this type of prior art. The discharge tube 1 has a pair of electrodes 3a and 3b arranged facing each other in an envelope 2 made of glass.
a, 3b are supported at predetermined positions by lead wires 5a, 5b, each of which has its intermediate portion fixed by the sealing part 4 of the envelope 2.

A polarity display mark 6 is attached to the stop surface of one lead wire 5a of the above-mentioned stop portion 4 using oil-based ink or paint, and this polarity display mark 6 allows the lead wire 5a to the anode or cathode to be identified from the outside. This makes it convenient for board mounting, socket mounting, etc.

[Problem to be solved by the invention]

However, as described above, when the polarity display mark 6 is applied using oil-based ink, when the discharge tube 1 is mounted on a board, there is a risk that the polarity display mark 6 will disappear during the cleaning process for removing flux, and the polarity was likely to be difficult to identify. In addition, forming the polarity display mark 6 using paint or the like requires a drying process for a certain amount of time after application, which not only increases the number of steps and working time but also requires a new drying mechanism, which increases costs. There were drawbacks.

In view of the above points, as described in Japanese Utility Model Publication No. 63-21894, a reducing burner flame is applied to the stopper of a tube made of lead glass to remove the lead oxide in the lead glass. A technique has also been proposed in which lead is precipitated by reduction and a polarity indicator is formed by utilizing the blackish color of lead. However, with the technology described in the above publication, although it is possible to deposit lead on the surface of the stopper, it is technically difficult to maintain the position and dimensions of lead deposit stably within the range required for polarity display. It was difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique that can provide a polarity display section easily and reliably without increasing the number of steps.

[Means to solve the problem]

In the present invention, after arranging electrodes each connected to an independent lead wire in the inner space of a tube made of glass, one end of the tube is held by a pair of clamping portions from a direction substantially perpendicular to the axial direction of the lead wire. When a sealing part is formed at one end of the tube by holding it with a jig equipped with a jig, the holding surface of the holding part is formed into an irregular shape, so that the corresponding sealing of the tube can be performed. The surface near where one lead wire is stopped on the part is processed into an irregular shape, and this is used as a polarity display part.

[Effect]

According to the above means, the polarity display section is provided at the same time as the blocking section is formed in the manufacturing process of the discharge tube. Furthermore, since the polarity display section obtained in this manner is a portion of the stopper section having an irregular shape, there is no risk of it disappearing even after subsequent steps such as cleaning. Therefore, with the above means, it is possible to reliably provide the polarity display section using a simple method.

Furthermore, by forming a concave portion as an irregularly shaped aspect and coloring the inner bottom surface of the concave shape, it becomes easier to visually identify the polarity. Furthermore, since the coloring is applied to the inner bottom surface of the concave shape provided in the stopper, it is difficult to disappear even after a subsequent cleaning process or the like.

Moreover, the above-mentioned irregular shape may be formed such that only one end in the planar direction of the restraining portion of the discharge tube is protruded or retracted.

〔Example〕

FIG. 1 is a process diagram sequentially showing the steps of stopping a discharge tube according to an embodiment of the present invention, and FIG. 2 is a diagram showing a discharge tube obtained by the above steps.

As shown in FIG. 2, the discharge tube 1 of this embodiment includes a pair of electrodes 3a within an envelope 2 made of glass.

The electrodes 3a and 3b are supported at predetermined positions by lead wires 5a and 5b, each of which has its intermediate portion fixed by a stopper 4 of the envelope 2. A characteristic feature of this embodiment is that a concave polarity display part 6 is formed on one side of the flattened sealing part 4 of the envelope 2, and an oil-based polarity display part 6 is formed on the inner bottom surface of the concave shape. The polarity display section 6 is colored with ink or the like, and when viewed from the outside, it is extremely easy to recognize the polarity display section 6.

The procedure for forming the polarity display section 6 of the discharge tube 1 will be described below.

First, as shown in FIG. 1, a glass tube for constructing the envelope 2 is prepared, and electrodes 3a and 3b formed in series with lead wires 5a and 5b are inserted from one end (upper end in the figure) of the glass tube. Then, the electrodes 3a and 3b are placed at predetermined positions in the inner space of the envelope 2 (FIG. 1(a)). Next, burner flame F is irradiated on one end side (upper side in the figure) of the envelope 2,
The one end is brought into a semi-molten state (FIG. 1(b)). In this state, one end of the envelope 2 is held in a direction substantially perpendicular to the axial direction of the lead wire using a sealing jig 7 (FIG. 1(C)) to form a flat sealing portion 4. (Figure 1(d)).

The sealing jig 7 used in this sealing process includes the support arm 7
It has a structure in which block-shaped clamping portions 7c and 7d are attached to the tips of portions a and 7b. The opposing surfaces of the clamping parts 7c and 7d are clamping surfaces 7e.

7f, and when one end of the envelope 2 is pressed by both clamping surfaces 7e and 7f, the one end portion which is in a semi-molten state is erased, and the one end side inside the envelope 2 is sealed. (Figure 1(d)).

The sealing jig 7 having the above structure is provided with a convex portion 8 having a height of about 0.5 mm from the clamping surface 7e on one clamping surface 7e. Such a convex portion can be easily formed by providing a concave portion in advance in the mold when forming the holding portion 7C using a mold (not shown). Further, the convex portion may be formed by forming a flat holding surface in advance, positioning it at a predetermined position on the flat surface, and attaching a bullet-shaped convex member using means such as welding.

In the sealing process using the sealing jig 7, a concave polarity display portion 6 is formed in the sealing portion 4 formed on the envelope 2 at a portion corresponding to the convex portion 8 of the clamping surface 7e. Ru.

Finally, by supplying a predetermined gas such as neon gas into the internal space of the envelope 2 and sealing the other end of the envelope 2 in a tapered shape, the discharge tube 1 shown in FIG. 2 can be obtained. can.

As described above, in this embodiment, since the polarity display section 6 can be formed at the same time as the sealing process in the sealing process, a discharge tube equipped with the polarity display section 6 can be obtained without increasing the number of steps. .

Further, since the polarity display section 6 of this embodiment has a recess directly provided in the sealing section 4, there is no fear that the polarity display section 6 will disappear even after the subsequent solder flux cleaning process or the like.

As described above, the polarity display section 6 having the recess structure makes it extremely easy to identify the polarity when mounting the discharge v1, but it is also possible to color the inner bottom surface of the recess of the sealing section 4 formed above. This makes it possible to more reliably identify the polarity by visual inspection from the outside. The colorant used at this time includes oil-based ink or paint. In this embodiment, since the inner bottom surface of the recess is colored in this way, there is an effect that the coloring is difficult to disappear.

Although the present invention has been specifically described above based on Examples, the present invention is not limited to the above Examples.

For example, although the sealing of one end of the glass tube by illuminating the burner flame F and clamping the sealing jig 7 is performed in one process to form the sealing part 4, the reliability of the internal airtightness is In order to increase the temperature, the irradiation step and the clamping step may be performed twice or more. In this case, it is only necessary that the final clamping step includes a step of processing into the above-mentioned irregular shape.

In addition, in the embodiment, the sealing part 4 is used as a polarity indicator 'giPJ6.
Although the structure is such that a concave portion is provided, the structure is not limited to a concave portion, but may be a convex portion. When the convex part is used as the polarity display part 6, there is an effect that the operator can more reliably recognize the polarity by touch during mounting, and also has the effect that the polarity can be recognized more reliably by the touch of the hand during mounting. It also has the effect of being suitable for recognition.

Furthermore, although the planar shape of the polarity display section 6 is circular in FIG. 2, it is not limited to such a simple shape. For example, as shown in FIG. It may also be in the shape of the letter "A". It should be noted that if the polarity display section 6 is formed in a different shape for each type of discharge tube 1, it will function as a type identification display section.

In the above explanation, the case where an irregular shape is provided on the surface of the sealing part 4 in cross section has been explained. It may also be used as a display section. Figure 4 shows an example of this.
Only the left side of the sealing part 4 in the drawing has a shape that projects in the plane direction, and this forms a polarity display part 6.

〔Effect of the invention〕

According to the present invention, since the polarity display section can be provided at the same time as the sealing section is formed, a discharge tube whose polarity can be easily identified can be provided without adding any additional steps.

Furthermore, it is possible to provide a discharge tube with a reliable polarity display section that is not likely to disappear using a simple method.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing the step of stabbing a discharge tube according to an embodiment of the present invention, FIG. 2 is a diagram showing a discharge tube obtained by the above steps, and FIGS. 3 and 4 are , a diagram showing a modification of the embodiment, and FIG. 5 is a diagram showing a discharge tube for explanation in the prior art. DESCRIPTION OF SYMBOLS 1...Discharge tube, 2...Envelope, 3a, 3
b...electrode, 4◆...sealing part, 5a. 6. ◆ 7◆ ◆ 7a. 7c. 7e. 8◆ ◆ 5b...Lead wire, ・Polarity display section, ・Sticking jig, 7b... Support arm, 7d... Holding part, 7f... Holding surface, ・Convex part.

Claims (4)

[Claims] (1) After placing electrodes each connected to an independent lead wire in the inner space of a glass tube, one end of the tube is held between a pair of electrodes in a direction substantially perpendicular to the axial direction of the lead wire. When forming a sealing part at one end of the tube by holding it with a jig equipped with a part, by forming the holding surface of the holding part in an irregular shape, it is possible to seal the corresponding tube. 1. A method for forming a polarity display part of a discharge tube, which comprises processing a surface near where one lead wire is sealed on the stop part into an irregular shape and using this as a polarity display part. (2), the unusual shape of the holding surface is a concave part or a convex part,
2. The polarity display portion of the discharge tube according to claim 1, wherein a convex portion or a concave portion is formed on a surface of the corresponding sealed portion of the bulb near where one lead wire is sealed. Formation method. (3) The method for forming a polarity display portion of a discharge tube according to claim 2, characterized in that, after providing a recess in the sealing portion, the inner bottom surface of the recess is colored. (4) The method for forming a polarity display portion of a discharge tube according to claim 1, wherein only one end of the sealing portion in a planar direction is formed into an irregular shape.