JP2819652B2 - Wells and tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a well having improved hermetic adhesion to glass and improved welding strength, and a bulb using the well.

2. Description of the Related Art Conventionally, wells sealed to glass members such as stems and bulbs of discharge lamps, high-power incandescent lamps, cathode ray tubes, picture tubes, and the like are disclosed in, for example, Japanese Patent Publication No. 52-888 (conventionally). Example 1) and JP-B-56-35027 (conventional example 2). Particularly, in Conventional Example 1, the wells are formed by welding a lead wire to one or both ends of a dumet wire.

It is described in Conventional Example 2 that a large-diameter portion is simply provided at the end of the dumet wire. However, the diameter is increased in order to stably press the semiconductor to the end of the dumet wire. The large diameter part is arranged at a position avoiding the sealing part due to the adhesion with glass,
In particular, there is no description or suggestion of connecting a lead wire to the large diameter portion.

Further, the microfilm of Conventional Application No. 62-4920 (Japanese Utility Model Application Laid-Open No. 63-116960) (conventional example 3) and the microfilm of Japanese Utility Model Application No. 61-42862 (Japanese Utility Model Application No. 62-153748) (conventional example 4) The three-part wells described in (1) are welded to one end of a dumet wire with an inner lead wire of a nickel-plated iron wire having a diameter larger than that of the dumet wire, and an outer lead wire of a large-diameter nickel wire or steel plated iron wire at the other end. Is formed by welding.

(Problems to be Solved by the Invention) Wells usually needs to reduce the hermetic sealability and the amount of strain with glass of different materials and different thermal expansion coefficients.
The diameter of the dumet wire embedded in the glass according to the use characteristics is as small as possible. On the other hand, the inner lead wire and outer lead wire connected to the dumet wire have a larger diameter than the dumet wire because of the current capacity, the retention of electrode components, and the connection with other components. Have been.

When welding a wire having such a large difference in wire diameter, generally, a welded portion having a cross-sectional area of a welded end surface which is substantially the same as a side having a small cross-sectional area or a fragment of a dumet wire end surface layer is formed in a welded portion. It may be buried, which may reduce the welding strength.

When this welding operation is performed by the arc percussion welding method, the mass productivity is excellent but the welding strength varies greatly. In addition, the welding point becomes large, and splash (weld splash) is liable to fly.

In addition, when resistance welding is used, the method uses a method in which the dumet wire is gripped by a conductive chuck and energized from the surface of the dumet wire. The layer must be removed beforehand. As the removing method, there are a method of washing the dumet wire with hot water or alcohol, and a method of breaking down the electric insulating layer by using a special needle-like chuck and energizing the wire.

However, if the electrical insulating layer of the dumet wire is removed or destroyed in this way, bubbles or foam streaks are generated at the time of sealing the dumet wire and the glass member, making it difficult to hermetically seal.

An object of the present invention is to provide a well having good airtightness with glass and high welding strength, and a tube using the well.

[Configuration of the invention]

(Means for Solving the Problems) The invention according to claim 1 excludes a core wire having a large diameter portion having an end face, a copper coating layer formed on the core wire except for the end face, and a large diameter portion. A dumet wire having a surface layer formed on the copper coating layer, and a lead wire having a larger diameter than the large diameter portion of the dumet wire welded to the end face of the large diameter portion of the dumet wire;
Is provided.

According to a second aspect of the present invention, there is provided a glass member constituting an airtight container; and a wells according to the first aspect sealed to the glass member.

(Operation) According to the invention of claim 1, since the dumet wire has the copper coating layer formed on the core wire except for the end face and the surface layer formed on the copper coating layer except for the large diameter portion, the lead is used. As the welding area with the wire increases, the large-diameter part formed by crushing the end face of the dumet wire has a conductive layer where the surface layer is destroyed and crushed as the diameter increases and the large-diameter core part becomes conductive. , The current flow is improved by contacting partly, and a good current flow can be achieved in the case of resistance welding, whereby a sufficient welding strength can be obtained.

Furthermore, when the portion other than the large diameter portion of the dumet wire is protected by the conductive chuck, the surface layer is not destroyed when the end portion is crushed, so that bubbles or foam streaks are generated at the time of sealing. It is possible to suppress the difficulty of hermetically sealing.

According to the second aspect of the present invention, since the wells of the first aspect are used, a highly reliable tube can be obtained.

(Examples) Hereinafter, details of the present invention will be described with reference to examples. First
The figure shows an example of three-part wells to which the present invention has been applied,
In the figure, 1 is a dumet wire having a wire diameter of 0.4 mm and a length of 2.0 mm, 2 is a nickel inner lead wire having a diameter of 0.6 mm, which is larger than the dumet wire 1 welded to one end of the dumet wire 1, and 3 Is a nickel outer lead wire having a larger diameter than the dumet wire 1 and having a diameter of 1.01 mm, which is connected to the other end of the dumet wire 1 by welding.

The above-mentioned dumet wire 1 is obtained by cutting a long dumet wire and pressing both ends thereof as described later to crush and form the large-diameter portions 12 and 12 having an outer diameter of 0.59 mm coaxially. ,
There is hardly any residue of the electrical insulating layer formed on the surface of the dumet wire 1 on the surface of the wire 12, and the entire diameter of the large diameter portions 12, 12 is welded to the lead wires 2, 3.

Next, the method of manufacturing the wells will be described with reference to FIGS.
This will be described with reference to the drawings. First, a long piece of dumet wire is cut into a length of about 2.2 mm longer than a specified dimension to produce a cut piece 13. Next, as shown in FIG. 2, the cut piece 13 is gripped by the metal divided cylindrical chuck 4 having a length of 1.8 mm corresponding to the effective length of the sealed portion 11 of the dumet wire. Then, the pressing dies 5 and 5 of the press are brought into contact with both end surfaces of the cut piece 13 of the dumet wire, and a heating current of 1 to
Pass for 2 seconds. Due to this energization, a dumet wire cut piece 13 having a small heat capacity in a portion not held by the chuck 4
The exposed portion at the end is heated. Then, as shown in FIG. 3, the pressing dies 5, 5 are operated in a direction approaching each other while interrupting or flowing the heating current, and the cut pieces of the dumet wire are cut.
The large-diameter portions 12 and 12 are formed by crushing both end surfaces of the thirteen.
Then, by separating the pressing dies 5, 5, the large-diameter portions
A dumet wire 1 having 12, 12 is obtained.

As shown in the enlarged view of FIG. 4, the dumet wire 1 formed in this manner has an effective sealed portion 11 which is held in close contact with the metal divided cylindrical chuck 4 so that it can be crushed. The triple structure of the core wire 15, the copper coating layer 16, and the surface layer 17 (a glass body composed of cuprous oxide Cu2O and borax) is not broken. On the other hand, since the end of the cut piece 13 is not protected by the chuck 4, the end is enlarged by crushing and the large diameter portions 12, 12 are formed.

In this state, as shown in FIG. 4, the end portion is crushed to have a large diameter, and is particularly pressed against the end surface of the chuck 4 so that a portion along the end surface becomes a flat surface and is generally substantially drum-shaped. become. Further, due to the crushing, the surface layer 17 at the end portion is vitreous and thus has poor spreadability, and cannot follow the enormous amount due to the crushing, and most of the crushing is broken and peeled off. Further, the copper coating layer 16 is softer and more ductile than the core wire 15 and is broken, so that cracks are generated not only in the oxide film portion on the surface but also in most of the copper coating layer 16 and in the surface of the crushed portion. The part is exposed. In particular, the copper coating layer 16 and the core wire 15 are in direct contact with the chuck 4 at a portion that comes into contact with the corner portion or the end face of the chuck 4, and the conductivity with the chuck 4 is improved. Also, when the end face is cut, the cut surfaces of the core wire 15 and the copper coating layer 16 are already exposed, and even if this is crushed, it is not covered by the surface layer 17.

Next, as shown in FIG. 5, the end face of the inner lead wire 2 also held by the metal chuck 7a is attached to the end face of one large-diameter portion 12 while holding the dumet wire 1 by the metal split cylindrical chuck 4. Is pressed, the switch 8 is put upward, and a predetermined voltage is applied from the welding power source 9 to perform resistance welding between the dumet wire 1 and the inner lead wire 2. Then, similarly to the above, the end face of the outer lead wire 3 held by the metal chuck 7b is pressed against the end face of the other large diameter portion 12, and a predetermined voltage is applied from the welding power source 9 by turning the switch 8 downward. Then, the outer lead wire 3 is welded to complete a desired wells.

As shown in FIG. 6, the wells obtained in this way are cross-sectionally shown in FIG. 6, and between the end face of the large diameter portion 12 of the dumet wire 1 and the end face of the inner lead wire 2, both are 12 and 12. Is formed, and the dumet wire 1 and the inner lead wire 2 are connected through the mixed melt layer 8. In addition, the diameter of the large-diameter portion 12 is about 0.59 mm, which is close to the diameter of the inner lead wire 2 of 0.60 mm.
The welding strength is sufficiently high. The surface layer 17 covering the surface of the sealed portion 11 is hardly peeled, punctured or scratched.

Further, since the wells are pressed and crushed while holding the cut pieces 13 of the dumet wire by the metal chuck 4, the surface layer 17 of the sealed portion 11 useful for sealing may be broken. Absent. In the crushing process, the current flowing between the pressing dies 5, 5 heats and softens both ends of the cut piece 13 so that the drum-shaped large-diameter portion 12 is easily formed by crushing. In addition, the end face of the large-diameter portion 12 has a core 15 and a copper coating layer.
16 and barely or no fragments of the surface layer 17 or the copper oxide film, and the surface layer 17
Since the inner lead wire 2 and the outer lead wire 3 are resistance-welded even when the copper oxide film remains, the fragments of the surface layer 17 and the copper oxide film hardly enter the mixed molten layer 8. Therefore, also for this reason, the welding strength is high,
Even if some residual fragments are present, the decrease in strength is small.

In addition, during resistance welding, the end face and the corner of the metal chuck 4 are in direct contact with the core wire 15 and the copper coating layer 16, so that the current-carrying resistance is small and a sufficiently large welding current can be obtained. The resistance welding of a large area can be satisfactorily performed.

In addition, this wells has a sealed portion 11 including the large diameter portions 12 and 12.
However, when it is embedded in the glass when sealed with a glass member forming a container such as a stem or a valve later, the airtightness is good, there is no leakage, and there is no disconnection from the connection part.

Next, in the above-described embodiment, the mechanical strength of the welded portion between the dumet wire 1 and the inner lead wire 2 was investigated, and this was compared with the conventional example having the same dimensions, that is, without the large-diameter portion 12 and washed with hot water. Compared to strength. The test was conducted for tensile strength and bending strength (passing at least 10 times in repetition of bending at 90 degrees left and right, and rejecting after 9 times was rejected). Further, each of the wells was sealed to a glass member and leaked. The incidence was investigated. The results of these tests are shown in the following table.

As is clear from this table, it was found that the example of the present invention had excellent mechanical strength, and the occurrence of leakage was remarkably reduced.

In addition, such a well is sealed with a glass member constituting a hermetic container such as a discharge lamp, a high-power incandescent bulb, a stem of a bulb such as a cathode ray tube or an image pickup tube, or a bulb, and the disconnection state at the welded portion of the wells is confirmed. did. This wells has excellent strength and air-tightness against heating when sealing the stem to the glass tube or glass bulb, and has enough strength to withstand the mounting members such as electrodes after assembly. It could be applied to various tubes without any problems.

In the wells of the present invention, the large diameter portion is formed by heating and crushing the end of the cut piece of the dumet wire, but the invention is not limited to this.
That is, it is not essential to heat the wells of the present invention at the time of crushing, and the large diameter portion may be formed by other means. For example, a copper wire and borax may be applied to a core wire in which small diameter portions and large diameter portions are alternately connected, and then cut to obtain a dumet wire. Any wells may be used in which a lead wire having a diameter larger than that of the dumet wire is butt-welded to the metal surface. In addition, welding is not limited to resistance welding.

Also, the wells of the present invention can be applied to two-part wells. In the case of two-part wells, the end of the dumet wire is gripped with a chuck so that an exposed portion does not come out, and only the other end is heated and softened. It may be crushed by a pressing die.

〔The invention's effect〕

According to the first aspect of the present invention, since the dumet wire has the copper coating layer formed on the core wire except for the end face and the surface layer formed on the copper coating layer except for the large diameter portion, the welding area with the lead wire is increased. As the diameter increases, the large-diameter portion formed by crushing the end face of the dumet wire has its surface layer destroyed as the diameter increases, and the crushed and enlarged core wire partly contacts the conductive chuck. As a result, good current can be applied when resistance welding is performed, and sufficient welding strength can be obtained.

Furthermore, when the portion other than the large diameter portion of the dumet wire is protected by the conductive chuck, the surface layer is not destroyed when the end portion is crushed, so that bubbles or foam streaks are generated at the time of sealing. It is possible to suppress the difficulty of hermetically sealing.

According to the second aspect of the present invention, since the wells of the first aspect are used, a highly reliable tube can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the wells of the present invention, and FIGS. 2 and 3 are explanatory views showing the dumet line crushing step of the embodiment of the manufacturing method of the wells of the present invention in order. FIG. 4 is an enlarged sectional view of a main part of the dumet wire obtained by the crushing step, FIG. 5 is an explanatory view of a lead wire welding step of the above embodiment, and FIG. 6 is a main part of a wells obtained by the welding step. It is an expanded sectional view. (1) ... Dumet wire, (11) ... Sealed part (12) ... Large diameter part, (13) ... Cut piece (15) ... Core wire, (16) ... Copper coating layer ( 17) Surface layer (8) Mixed layer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 5/46 H01J 9/28

Claims (2)

(57) [Claims] 1. A dumet having a core wire having a large diameter portion having an end face, a copper coating layer formed on the core wire excluding the end face, and a surface layer formed on the copper coating layer excluding the large diameter portion. And a lead wire having a diameter larger than that of the large diameter portion of the dumet wire welded to the end face of the large diameter portion of the dumet wire. 2. A tube comprising: a glass member forming an airtight container; and the wells according to claim 1, which is sealed to the glass member.