JPS58216336A - Production process of cathode-ray tube - Google Patents

Abstract

PURPOSE:To eradicate the breakdown of glass due to thermal distortion of the captioned tube and enhance the productivity thereof, by installing a thermal shielding protector around the external peripheral part of a stem-sealing part and by reducing the temperature difference between the external peripheral part and the centeral part of the stem-sealing part. CONSTITUTION:A cylindrical thermal shielding protector 14 is positioned on a shocket 6, and shields the radiant heat H from a heat source 9 by surrounding the external peipheral part 5a of a stem-sealing part 5. The temperature rise in the external peripheral part 5a becomes gentle, and the temperature difference between the external peripheral part 5a and the centeral part 5b becomes small. It is also not impossible to maintain the temperature difference corresponding to the thermal distortion less than 1/5 of the tensile strength of glass, by decreasing the clearance 15 between the thermal shielding protector 14 and the stem-sealing part 5 and by selecting such substance having small thermal conductivity for the sake of the material of the thermal shielding protector 14; consequently, the problem of glass breakdown caused by thermal distortion can be eradicated.

Description

【発明の詳細な説明】 この発明はステム封着部のガラス割れに対処した陰極線
管の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cathode ray tube that deals with glass breakage at the stem sealing portion.

第１図は従来の陰極線管（１）の排気処理工程図である
。この図において、（２）はガラスバルブ、（３）はガ
ラスパルプ（２）の一部を構成するネック部、（４）は
ネック部（３）の端部に突°出したチップ管、（５）は
ネック部（３）の端部のステム封着部、（６）はソケッ
ト、（７１は排気口、（８）は高周波コイル、（９）は
排気炉の熱源である。FIG. 1 is a diagram showing a conventional evacuation treatment process for a cathode ray tube (1). In this figure, (2) is a glass bulb, (3) is a neck part that constitutes a part of glass pulp (2), (4) is a chip tube protruding from the end of neck part (3), ( 5) is a stem sealing portion at the end of the neck portion (3), (6) is a socket, (71 is an exhaust port, (8) is a high-frequency coil, and (9) is a heat source for the exhaust furnace.

一般に、陰極線管（１）の排気処理においては第２図に
示すように、チップ管（４）を通じて排−気口（７）よ
シ真空ポンプ（図示せず）を用いて陰極線管（１）内の
空気、およびその他のガスを排気し、高真空にしている
が、その際に陰極線管（１）の各部を高温（通常、１０
０〜４００℃）Ｋｌて、吸蔵ガスを十分排出しておくこ
とが、高品位の陰極線管（１）を得る上で非常に大切な
ことである。そのために第１図に示す熱源（９）にて陰
極線管（１）の全体を加熱すると同時に、第２図に示す
ように高周波コイル（８）で電子銃側も加熱する。また
、電子銃叫のヒータ（図示せず）にリード圓、ソケット
（６）に取り付けられた電圧印加端子Ｕを通じて電流を
流すことにより、カソード（図示せず）の加熱処理を行
うことも排気処理の重要な工程の一つであることは良く
知られていることである。すなわち、陰極線管（１）−
の製造にあたっては、上記のように各部を加熱処理して
、陰極線管（υの各部よシ各種のガスを排出させ、排気
口（７）より排気し、陰極線管（１）内を高真空にして
いる。Generally, in the evacuation process of the cathode ray tube (1), as shown in FIG. The air and other gases inside the cathode ray tube (1) are evacuated to create a high vacuum. At this time, each part of the cathode ray tube (1) is heated to a high temperature (usually
It is very important to sufficiently discharge the occluded gas at a temperature of 0 to 400° C. in order to obtain a high-quality cathode ray tube (1). For this purpose, the entire cathode ray tube (1) is heated by a heat source (9) shown in FIG. 1, and at the same time, the electron gun side is also heated by a high frequency coil (8) as shown in FIG. In addition, heat treatment of the cathode (not shown) can also be performed by passing current through the lead circle and voltage application terminal U attached to the socket (6) to the heater (not shown) of the electron gun. It is well known that this is one of the most important processes. That is, cathode ray tube (1)-
In manufacturing the cathode ray tube (υ), each part is heat-treated as described above, various gases are exhausted from each part of the cathode ray tube (υ), and the gases are exhausted from the exhaust port (7) to create a high vacuum inside the cathode ray tube (1). ing.

その後、チップ管（４）を所定箇所より封止切シ（図示
せず）して、排気処理を終えるわけである。Thereafter, the tip tube (4) is sealed off at a predetermined location (not shown) to complete the exhaust process.

ところで、近年、陰極線管（１）の多量生産、ならびに
生産性の向上のため、陰極線管（１）の排気処理時間を
短縮する傾向にあり、それがため、陰極線管（１）を短
時間に常温から高温く温度上昇させることとなシ、必然
的に加熱時の各部の温度差は大きくなる。その結果、各
部に熱歪が発生してガラス割れの多発を招いている。By the way, in recent years, in order to mass produce cathode ray tubes (1) and improve productivity, there has been a trend to shorten the evacuation processing time of cathode ray tubes (1). When the temperature is raised from room temperature to a high temperature, the temperature difference between each part during heating inevitably becomes large. As a result, thermal strain occurs in various parts, leading to frequent glass breakage.

特に構造が複雑で、金属製のリード圓を含むステム封着
部（５）には極部的に非常に大きな熱歪が生じやすいた
め、この箇所のガラス割れの多発は非常に深刻である。In particular, the stem sealing part (5), which has a complicated structure and includes a metal lead circle, tends to undergo very large thermal strain locally, so the frequent occurrence of glass cracks in this part is very serious.

すなわち、第２図に示すように、ステム封着部（５）の
外縁部（５ａ）が熱源（９）の輻射熱Ｈによシ加熱され
るが、ガラスは熱伝導が悪いため、中心部（５ｂ）の温
度はそれほど上昇しない。その結果、ステム封着部（５
）には、第８図に示すように外縁部（５ａ）と中心部（
５ｂ）間に温度差が生じ、半径方向に張力の熱歪Ｆが発
生する。That is, as shown in FIG. 2, the outer edge (5a) of the stem sealing part (5) is heated by the radiant heat H of the heat source (9), but since glass has poor thermal conductivity, the center part (5a) is heated by the radiant heat H of the heat source (9). The temperature in 5b) does not increase much. As a result, the stem sealing part (5
) has an outer edge (5a) and a center (5a) as shown in Figure 8.
5b) A temperature difference occurs between the two, and a tensile thermal strain F occurs in the radial direction.

この熱歪Ｆによる応力がガラスの抗張力を越えると、第
８図、第４図に示すようなガラス割れ（１３が発生し、
その陰極線管（１）は不良となるわけである。When the stress caused by this thermal strain F exceeds the tensile strength of the glass, glass cracking (13) as shown in Figures 8 and 4 occurs.
The cathode ray tube (1) becomes defective.

この発明は上記欠点を解消するためになされたもので、
ステム封着部の外縁部の周囲に熱しゃへい具を設け、ス
テム封着部の外縁部と中心部間の温度差を小さくするこ
とにより、熱歪によるガラス割れを一掃し、生産性の高
い陰極線管の製造方法を提供することを目的とする。This invention was made to eliminate the above drawbacks.
By installing a heat shield around the outer edge of the stem sealing part and reducing the temperature difference between the outer edge and the center of the stem sealing part, glass cracking due to thermal distortion is eliminated and cathode rays with high productivity are achieved. The purpose of the present invention is to provide a method for manufacturing a pipe.

以下、この発明の実施例を図面にしたがって説明する。Embodiments of the present invention will be described below with reference to the drawings.

第５図はこの発明の一実施例にかかる陰極線管の要部断
面図である。この図において、Ｉは円筒形の熱しゃへい
具であシ、ソケット（６）の上部に位置し、ステム封着
部（５）の外縁部（５ａ）を取９囲んで熱源（９）の輻
射熱Ｈからしゃへいするようになっている。同図より明
らかなように輻射熱Ｈは直接ステム封着部（５）にあた
らないため、ステム封着部（５）の外縁部（５ａ）の温
度上昇はゆるやかとな　　□シ、この外縁部（５ａ）と
中心部（５ｂ）間の温度差は熱しゃへい具Ｉがない場合
よシがなシ小さくなる。すなわち、熱しゃへい具（１４
）とステム封着部（５）とのすき間（至）を小さくし、
熱しゃへい具（１滲の材料に熱伝導の小さいものを選ぶ
ことにより、ガラスの抗張力の１７５以下の熱歪に相当
する温度差に止めるのも不可能ではなく、熱歪によるガ
ラスの割れの問題を一掃することができる。FIG. 5 is a sectional view of a main part of a cathode ray tube according to an embodiment of the present invention. In this figure, I is a cylindrical heat shield, which is located on the upper part of the socket (6) and surrounds the outer edge (5a) of the stem sealing part (5) to prevent the radiant heat from the heat source (9). It is designed to be shielded from H. As is clear from the figure, since the radiant heat H does not directly hit the stem sealing part (5), the temperature rise at the outer edge (5a) of the stem sealing part (5) is gradual. The temperature difference between 5a) and the center (5b) is much smaller than without the heat shield I. In other words, a heat shield (14
) and the stem sealing part (5),
By choosing a material with low thermal conductivity for the heat shield (1), it is not impossible to limit the temperature difference to a temperature difference equivalent to a thermal strain of 175 or less of the tensile strength of glass, which may cause the problem of glass cracking due to thermal strain. can be wiped out.

以上の説明から解るように、この発明によれば、ガラス
割れの発生しやすいステム封着部を急速に加熱処理して
も熱歪によるガラス割れがなく、陰極線管の多量生産に
適した生産性の高い製造方法が得られる。As can be seen from the above description, according to the present invention, there is no glass cracking due to thermal strain even if the stem sealing part, which is prone to glass cracking, is rapidly heat-treated, and the productivity is suitable for mass production of cathode ray tubes. A manufacturing method with high efficiency can be obtained.

なお、この発明における熱しゃへい具は温度上昇時だけ
でなく、温度下降時にも有効で、その材料および形状を
適当に選べば、保温の役目をし、冷却時の熱歪によるガ
ラス割れの防止に役立つことはいうまでもない。The heat shield of this invention is effective not only when the temperature rises but also when the temperature falls.If the material and shape are selected appropriately, it can serve as a heat insulator and prevent glass breakage due to thermal distortion during cooling. Needless to say, it's helpful.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来の陰極線管の製造方法を示す説明図、第２
図は第１図の主要部を示す一部切欠拡犬側面図、第３図
および第４図は従来方法によるガラス割れを示す説明図
、第５図はこの発明の一実施例にかかる陰極線管の製造
方法を示す説明図である。 （１）・・・陰極線管、（５）・・・ステム封着部％　
（５ａ）・・・外縁部、Ｉ・・・熱しゃへい具。 なお、図中同一符号は同一または相当部分を示す。 代理人葛野信−（外１名） 第１　図 第２区 ／ 第３図 第４×Figure 1 is an explanatory diagram showing the conventional manufacturing method of cathode ray tubes;
The figure is a partially cutaway enlarged side view showing the main part of Figure 1, Figures 3 and 4 are explanatory diagrams showing glass breaking by the conventional method, and Figure 5 is a cathode ray tube according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a manufacturing method. (1)...Cathode ray tube, (5)...Stem sealing portion%
(5a)...outer edge, I...heat shield. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1, 2nd ward/ Figure 3, 4x

Claims (1)

【特許請求の範囲】[Claims] （１）陰極線管の排気に際し、少なくとも上記陰極線管
のステム封着部を加熱する陰極線管の製造方法において
、上記ステム封着部の外縁部を熱しゃへい具によ−９取
り囲むことを特徴とする陰極線管の製造方法。(1) A method for manufacturing a cathode ray tube in which at least the stem sealing part of the cathode ray tube is heated when the cathode ray tube is evacuated, characterized in that the outer edge of the stem sealing part is surrounded by a heat shield. A method of manufacturing cathode ray tubes.