JPH0388236A - Sealing method for tubular bulb - Google Patents

Abstract

PURPOSE:To reduce the number of parts, decrease the processes, make the axial size of a sealing part smaller, and make an effective emission length larger compared with the whole length of a bulb by regulating the current of fused glass by a recess part to close the bulb, and sealing lead wires with this fused glass. CONSTITUTION:A bulb terminal part is inserted into a recess part of a sealing die 10, and the sealing die is heated, so the terminal part is fused by heat from the sealing die 10, and that the form of the fused glass is regulated by the recess part in the sealing die 10 to be a closing wall for closing the bulb terminal part for sealing lead wires 5 with the closing wall. The bulb terminal part can therefore be closed while sealing the lead wires 5 without using a special part, so the number of parts can be reduced, and the manufacturing processes can also be reduced because the bulb aperture terminal part need only be fused by heat transmission from the sealing die. A bulb 1 is thus closed by the fused glass, so the axial size of the closing wall can be smaller, and because a size (l) can be small, the ratio of the effective light emission length to the whole bulb length can be larger.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to
The present invention relates to a method of sealing the mouth end.

(Prior Art) Fluorescent lamps are used as light sources for various office automation equipment, such as backlights for liquid crystal display devices. Recent O
A device is becoming smaller and smaller, and the fluorescent lamp used as a light source is also required to be smaller and have higher output.

In order to miniaturize and increase the output of fluorescent lamps, improvements have been made to make the bulbs thinner or flattened.

However, measures to shorten the overall length of the valve are still insufficient. That is, a fluorescent lamp has electrodes sealed at both ends of an elongated glass bulb, and since discharge occurs between these two electrodes, the area between these two electrodes becomes an effective light emitting area. However, the area from the electrode to the end of the bulb at the rear has a small amount of light, and is considered a non-light-emitting area, although it does not emit light at all.

Therefore, if the length of the non-light emitting part (g shown in Figure 4) can be shortened without changing the length of the effective light emitting part, the total length of the bulb can be shortened, and the fluorescent lamp can be made smaller. This will greatly contribute to the development of

One way to shorten the length from the electrode to the back end of the bulb, that is, the length of the non-light-emitting part, is to move the electrode closer to the sealed end of the bulb. If placed too close to the end, the heat that heats the bulb during the sealing process will heat the electrodes, leading to thermal deterioration of the electrodes. Further, when the electrode is a hot cathode, there is a problem in that the heat of the electrode during lighting heats the sealing part, causing cracks in the sealing part. For this reason,
There are limits to how close the electrode can be to the sealed end of the bulb.

Therefore, it is conceivable to reduce the axial dimension occupied by the sealing portion.

That is, when sealing the end of a valve, the most common structure is to use a flared stem, but since the flared stem has a relatively large axial dimension, the height of the electrode from the end of the valve becomes larger, and the dimension p becomes larger.

In addition, as another means, a crushing sealing structure may be adopted in which the valve end is crushed in the radial direction, but the crushing sealing part needs to have a considerably large dimension in the axial direction due to the molded shape, so this also applies. The dimension g increases.

It is known to use a button stem instead of these sealing structures.

Since the button stem is a thin plate-shaped stem joined to the open end of the valve, the thickness of the button stem itself is small, and the axial dimension of the sealing part can be reduced. Can be made smaller.

(Problems to be Solved by the Invention) However, when sealing a valve with a button stem, it is necessary to seal a lead wire hermetically through the button stem in advance, and to attach an electrode to the lead wire. That is, a method must be adopted in which an electrode mount is constructed in advance from a button stem, a lead wire, and an electrode, and such an electrode mount is sealed to the end of the bulb.

In the case of such a sealing method, the electrode mount must be manufactured in advance, so many manufacturing steps are required.
Furthermore, since a special button stem is required, there are problems such as an increase in the number of parts.

In the present invention, the number of parts and processes are reduced, and the axial dimension of the sealing part can be reduced, making it possible to increase the effective light emitting length in the total length of the bulb. The aim is to provide a method to stop this.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention has a recess into which the open end of the glass bulb to be sealed is inserted, and a bottom surface of the recess. The electrode mount is provided with a sealing mold having a lead wire insertion hole into which the lead wire of the electrode mount is inserted, and the electrode mount is supported upright by inserting the lead wire of the electrode mount into the lead wire insertion hole. The valve is supported upright by inserting the open end of the valve into the recess of the sealing mold and bringing the open end of the valve into contact with the sealing mold. Heat is transferred from the molten glass to the end of the bulb to melt the end of the bulb, and the flow of the molten glass is regulated by the recess to close the bulb, and the molten glass seals the lead wire. It is characterized by

(Function) According to the present invention, the open end of the bulb receives heat from the sealing mold and melts, and the shape of this molten glass is regulated by the recess of the sealing mold to close the valve end. It becomes a closing wall and also seals the lead wire with this closing wall. Therefore, since the end of the valve is closed and the lead wire is sealed without using special parts such as a button stem, the number of parts can be reduced, and the open end of the valve can be closed by heat conduction from the sealing mold. Since it only needs to be melted, there are fewer manufacturing steps. Moreover, since the bulb is closed by molten glass, the axial dimension of the closed U wall can be reduced, and one dimension can therefore be reduced, so that the effective light emitting length that occupies the entire length of the bulb can be increased.

Therefore, if the effective light emitting lengths are made the same, the overall length of the bulb can be shortened, and conversely, if the full bulb lengths are made the same, the effective light emitting length can be increased.

(Example) The present invention will be described below based on a first embodiment flj shown in FIGS. 1 to 4.

FIGS. 1 to 3 are explanatory diagrams showing the process of sealing a flat fluorescent lamp in order of operation, and in the figures, 1 indicates the glass bulb of the fluorescent lamp to be sealed. The glass bulb 1 has a flat cross section, such as an ellipse or an ellipse, as shown by the two-dot chain line in FIG. 4, for example. Note that the ratio of the short axis to the long axis of the flat shape is approximately 0.65:1.

The inner surface of the bulb 1 is coated with a phosphor coating 2 over a predetermined area.
is coated.

Reference numeral 3 designates an electrode mount, and the electrode mount 3 of this embodiment includes a cold cathode electrode 4 to which a mercury alloy body (not shown) is attached, and a pair of glue electrodes 1! bonded to this electrode 4. 5.5. The lead wire 5.5 is made of, for example, a Dumet wire having a coefficient of thermal expansion close to that of the glass bulb 1, at least in its sealing portion with the glass.

Reference numeral 10 denotes a sealing mold as a jig used for sealing the end of the valve, and the sealing mold 10 is made of metal or heat-resistant carbon with excellent thermal conductivity.

The sealed mold 10 is heated by an external heater (not shown) or heated by electrical resistance heat generation, so that the surface thereof reaches a temperature higher than the melting point of the glass (for example, about 1000° C.). ing.

A recess 11 into which the open end of the bulb 1 is inserted is formed on the upper surface of the sealing mold 10, and the inner peripheral surface of the recess 11 has a tapered surface 12 so that the glass flows smoothly.
It becomes. The lead wire 5 is attached to the bottom of the recess 11.
．． A lead wire insertion hole 13.13 is formed into which the lead wire 5 is inserted and held in an upright position.

Note that the lead wire insertion hole 13.13 of this embodiment has a bottom, and when the lead wire 5.5 is inserted, the lead wire 5.5
The lower end of the electrode 4 bottoms out, thereby restricting the height of the electrode 4 protruding from the bottom surface of the recess 11.

A method of sealing the open end of the valve 1 using such a sealing mold 10 will be explained.

As shown in FIG. 1, the pair of lead wires 5.5 of the electrode mount 3 are inserted into the lead wire insertion holes 13.13 of the sealing mold 10, and the lead wires 5.5 are inserted through these lead wire insertion holes 13.13. It supports upright and thus holds the electrode mount 3.

In this case, the lead wire 5.5 is connected to the lead wire insertion hole 13.13.
The protruding height of the electrode 4 is thereby regulated.

Covering such an electrode mount 3, the bulb 1 is attached to a sealing mold 10 as shown in FIG.

In this case, the bottom opening end face of the valve 1 is sealed! It is inserted into the recess 11 of E210 and brought into contact with the tapered surface 12 formed on the inner peripheral surface of the recess 11. The middle or upper end of the valve 1 is held by a vertically movable valve holder 15 to prevent the valve 1 from falling over.

A stopper 16 is provided below the valve holder 15 to restrict the amount of descent of the valve 1, and the valve holder 15 can come into contact with the stopper 16.

In this way, when the bulb 1 comes into contact with the tapered surface 12 of the sealing mold 10 and is maintained in an upright position, the sealing mold 10 generates heat. The sealing mold 10 is heated by an external heater (not shown) or heated by electrical resistance heat generation, thereby causing the recess 1
The tapered surface 12 of 1 generates heat.

The heat of the tapered surface 12 is transferred to the lower open end of the bulb 1 that is in contact with the tapered surface 12, thereby heating the lower open end of the bulb 1.

When the lower open end wall of the bulb 1 heated in this manner reaches the melting point of glass (for example, about 1000° C.) or higher, the lower open end wall of the bulb 1 softens and melts.

This molten glass flows along the tapered surface 12 to the bottom surface of the recess 11. As the amount of melted glass on the bottom opening end surface of the bulb 1 increases, the amount of glass flowing to the bottom surface of the recess 11 increases, and as the bottom opening end wall of the bulb 1 melts, the bulb 1 gradually descends.

When the valve holder 15, which holds the valve 1 to prevent it from falling, hits the stopper 16, the valve 1 is prevented from falling any further.

At this time, a predetermined amount of molten glass accumulates on the bottom of the recess 11 of the sealing mold 10, as shown in FIG. This serves as a sealing wall 6, which seals the lead wire 5.5 through it in an airtight manner.

In this state, the heat generation of the sealing mold 10 is stopped, and the molten glass is cooled and solidified. Then, when the molten glass solidifies, the bulb 1 is taken out from the sealing mold 10.
As shown in FIG. 4, a valve 1 whose end portion is sealed with a sealing wall 6 is obtained.

According to this sealing method, the end of the valve 1 is closed with the sealing wall 6 made by melting the end wall of the valve 1, so there is no need for a special button stem, and the number of parts is small. I'll try it.

In addition, since the sealing mold 6 is created by melting and flowing the end wall of the valve 1, there are no restrictions on the shape of the end of the valve 1, and even a particularly flat valve can be easily sealed. be able to.

As the molten glass at the end of the bulb 1 flows, the lead wire 5.5 is hermetically penetrated and sealed, making it possible to close the bulb 1 and seal the lead wire 5.5 at the same time, greatly reducing the work process. This reduces manufacturing time.

Furthermore, since these operations can be carried out using only the sealing die 10, there is no need for a special crushing sealing machine or flare manufacturing machine, and the equipment cost is also reduced.

Further, in the fluorescent lamp manufactured in this manner, the thickness of the sealing wall 6 at the end portion may be approximately the thickness of the side wall, and therefore the dimension of the sealing wall 6 in the bulb axis direction may be extremely thin. . Therefore, the length from the tip of the electrode 4 to the rear end of the bulb (g shown in FIG. 4), that is, the length of the non-light-emitting portion can be shortened.

Therefore, by shortening the length of the non-light-emitting portion p, the total length of the bulb can be shortened without changing the effective light-emitting length (L-i), which greatly contributes to miniaturization of the fluorescent lamp.

Conversely, if the total length of the bulb is not changed, the non-light emitting part g
The effective light emission length (L-i) can be increased by the shorter length.

In addition, in the case of the above embodiment, the recess 11 in the mold 1o
Since the side surface is tapered as the tapered surface 12, the flow of the molten glass becomes smooth, the molten wall of the bulb side wall can be effectively used for the sealing wall 6, and the thickness of the sealing wall 6 can be made uniform. can do.

Moreover, with such a tapered surface 12, when removing the valve 1 from the mold 10, it can be easily demolded.

Note that the present invention is not limited to the above embodiments.

That is, FIGS. 5 and 6 show a second embodiment of the present invention.

In this second embodiment, the sealing mold also serves as the cap 2°. That is, the cap 2o is made of a metal plate with excellent thermal conductivity, and has a cap shape suitable for being placed over the open end of the bulb 1.

The cap 20 has a lead wire insertion hole 22.22 formed in the bottom wall of the recess 21 into which the open end of the valve 1 is inserted, through which the lead wire 5.5 passes.

The cap 2o, which also serves as a sealing type, is used as a heating stand 2.
It is placed on 5. This heating table 25 is heated by an external heater or heated by electrical resistance heat generation, so that the upper surface thereof generates heat, and the heat of this heating table 25 is transmitted to the cap 2o, raising the temperature of the cap 20. It is designed to rise.

The heating table 25 is formed with a support hole 26.26 into which the lead wire 5.5 passed through the lead wire insertion hole 22.22 is inserted.

In the case of such a configuration, as shown in FIG. 5, the cap 20 is placed on the heating table 25, and the pair of lead wires 5.5 of the electrode mount 3 are inserted into the lead wire insertion holes 22.22 formed in the cap 20. through the support hole 26. of the heating table 25.
Insert into 26. As a result, the lead wire 5.5 is supported by the lead wire insertion hole 22.22 and the support hole 26.26 and stands upright, so that the electrode mount 3 is held upright and the position of the electrode 4 is determined.

Covering such an electrode mount 3, the lower open end of the bulb 1 is inserted into the recess 21 of the cap 20, and the recess 21 is inserted into the recess 21 of the cap 20.
touch the bottom of the Then, the middle part or the upper end part of the knob 1 is held by a knob holder 15 which is vertically movable to prevent the valve 1 from falling over.

Next, the heating table 25 is heated by an external heater or electric resistance heat generation, and the heat of the heating table 25 is transferred to the cap 20. Therefore, the temperature of the cap 20 rises, and this heat is transferred to the lower open end of the bulb 1 that is in contact with the cap 20, so that the lower open end of the bulb 1 is heated. As a result, the lower opening end wall of the bulb 1 softens and melts.

This molten glass flows along the bottom surface of the cap 20 toward the center. When the glass flowing to the bottom of the recess 21 closes the lead wire insertion hole 22.22 formed in the cap 20 and flows further to the center, the heating stage 25 stops generating heat (heating), and the molten glass is cooled. and solidify.

Then, since the molten glass is bonded to the cap 20 and also closes the lead wire insertion holes 22.22, the open end of the bulb 1 is tightly closed by the cap 20 and the molten glass wall 27.

In this case, if the molten glass wall 27 is spread over the entire bottom surface of the cap 20, that is, if it is brought into contact with the entire surface of the cap 20 as shown by the imaginary line in FIG. However, in the case of this embodiment, since the cap 20 has a closing function, if only the lead wire insertion holes 22 and 22 are closed with the molten glass wall 27, that is, the cap 20
Even if there is no molten glass in the center of the bottom surface of the bulb 1, the open end of the bulb 1 can be mainly closed with the cap 20.

Further, FIG. 7 shows a third embodiment of the present invention.

This third embodiment is an example in which the electrode 4 is arranged close to the sealed end, and is applicable when the electrode 4 is a cold cathode. In this case, the dimension p corresponding to the non-light-emitting portion shown in FIG. 4 can be further reduced.

Furthermore, FIG. 8 shows a fourth embodiment of the present invention,
This will be explained below.

That is, in the case of the first to third embodiments described above, the lead wire insertion holes 13.13 formed in the sealing mold 10 or the support holes 26.26 formed in the heating table 25 each have a bottom, and these leads Wire insertion hole 13.13 or support hole 26.
26 regulates the insertion depth of the lead wire 5.5 and connects the electrode 4.
The height position is regulated.

However, since the lead wire 5.5 usually has a considerable length, when trying to determine the height of the electrode 4 using the bottomed hole 13.26, it is difficult to use the sealing mold 10 or heating. The thickness of the stand 25 is required to be considerably large.

When the thickness of the sealing mold 10 and the heating table 25 increases,
Since the heat capacity increases, a long time is required for cooling after heating, and a long time is required for cooling and solidifying the melted seal 96, 27. This may cause the valve end to deform while waiting for cooling, or lead wire 5.5 and sealing wall 6.27 to
There is a concern that a temperature difference will occur between the two, leading to problems such as sealing failure.

Therefore, in the case of this embodiment, a lead wire insertion hole 31 is formed in the sealing mold 30 through which one of the pair of lead wires 5.5 connected to the cold cathode electrode 4 is passed. At the same time, the length of the other lead wire 5 is shortened to form the sealed type 3.
This is so that it hits the bottom surface of the recess 11 formed at 0.0. Note that the bottom of the recess 11 has a recess 32 for positioning.
This is provided.

In this way, the other shortened lead wire 5 can be connected to the electrode 4.
This lead wire 5 is inserted through the lead wire insertion hole 31, and the electrode 4 is positioned at a predetermined position using both lead wires 5. Therefore, in the same way as in the first embodiment, in such an electrode supported state, the temperature of the sealing mold 30 is increased, and this heat is transferred to the end of the bulb 1 to melt the end of the bulb 1, thereby making the bulb. 1 can be sealed.

In this case, one lead wire 5 passes through the lead wire insertion hole 31, and the other lead wire 5 regulates the height of the electrode 4, so the thickness t of the sealing mold 30 can be reduced.
Since the heat capacity of the sealing mold 30 can be reduced, the cooling time of the sealing mold 30 is shortened, and the time for cooling and solidifying the molten sealing wall is shortened. This may cause the valve end to deform while waiting for cooling, or lead wire 5.5 and sealing wall 6.27 to
Problems such as sealing failure caused by a temperature difference between the two are reduced.

The fifth embodiment shown in FIG. 9 is a modification of the technical idea of the fourth embodiment.

That is, in the case of the fourth embodiment, the other lead wire 5
The height of the electrode 4 was regulated by shortening the length so that it touched the bottom of the recess 11 formed in the sealing mold 30, and fitting it into the positioning recess 32 formed in the bottom of the recess 11. In the case of this embodiment shown in the figure, the height of the wire 14 is regulated by bending the other lead wire 5 and bringing the bent portion 5a into contact with the bottom surface of the recess 11.

Furthermore, the sixth embodiment shown in FIG. 10 is an example in which the technical concept of the fourth embodiment is applied to the hot cathode type electrode 40, and the lead wire 41 connected to the hot cathode type electrode 40 is ．．
41 are bent in the middle, and these bent portions 41a, 4
The height of the electrode 4 is regulated by applying the electrode 1a to the bottom surface of the recess 11 of the sealing mold 30. Recess 1 of sealing mold 30
1 has lead wire insertion holes 42.42 through which these leads 1j141.41 are passed. Note that 43 is an electron emitting substance (emitter).

Even in this case, the bent portions 41a, 41a formed in the middle of the lead wires 41.41 come into contact with the bottom surface of the recess 11 of the sealing mold 30, thereby regulating the height of the electrode 4. The length of the hole 42 can be shortened, and the thickness t of the sealing mold 30 can be reduced.

Furthermore, the present invention is not limited to fluorescent lamps, but can be applied to rare gas discharge lamps and incandescent lamps, especially small types, and the electrodes are not limited to cold cathodes, but can also be hot cathodes. good.

Further, the shape of the bulb is not limited to a flat shape, but may be circular or the like.

[Effects of the Invention] As explained above, according to the method of the present invention, when the valve end is inserted into the recess of the sealing mold and the sealing mold is made to generate heat,
This end melts when it receives heat from the sealing mold, and the shape of this molten glass is regulated by the concave part of the sealing mold, forming a closing wall that closes off the end of the valve. This will seal the wire. Therefore, since the end of the valve is closed and the lead wire is sealed without using special parts such as a button stem, the number of parts can be reduced, and the open end of the valve can be closed by heat conduction from the sealing mold. Since it only needs to be melted, there are fewer manufacturing steps. Moreover, since the bulb is closed by molten glass, the axial dimension of the closing wall can be reduced, and therefore two dimensions can be reduced, so that the effective light emitting length that occupies the entire length of the bulb can be increased. Therefore, if the effective light emitting lengths are made the same, the overall length of the bulb can be shortened, and conversely, if the full bulb lengths are made the same, the effective light emitting length can be increased.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, and FIGS. 1, 2, and 3 are explanatory diagrams showing the order of work steps,
FIG. 4 is a perspective view showing the end of the valve after sealing, FIGS. 5 and 6 are explanatory diagrams showing the second embodiment of the present invention in order of work steps, and FIG. 7 is a third embodiment of the present invention. FIG. 8 is an explanatory diagram showing an embodiment of Ji4 of the present invention.
The figure is an explanatory diagram showing a fifth embodiment of the invention, and FIG. 10 is an explanatory diagram showing a sixth embodiment of the invention. 1... Valve, 3... Electrode mount, 4.40...
・Electrode, 5.41...Lead wire, 10.20.30・
...Sealing type, 13.26.31.42... Lead wire insertion hole, 6.27... Molten glass wall.

Claims (1)

[Claims] A sealing mold having a recess into which the open end of the glass bulb to be sealed is inserted, and a lead wire insertion hole formed in the bottom surface of the recess into which the lead wire of the electrode mount is inserted; Insert the lead wire of the electrode mount into the lead wire insertion hole, support the electrode mount upright, cover the electrode mount, insert the open end of the bulb into the recess of the sealing mold, and insert the open end of the bulb into the recess of the sealing mold. The valve is supported upright by bringing the part into contact with the sealing mold,
Heat is transferred from the sealing mold to the end of the bulb to melt the end of the bulb, and the flow of the molten glass is regulated by the recess to close the bulb, and the molten glass is used to connect the lead wire. A method for sealing a tube, the method comprising: sealing a tube.