JPH0523089U - Vacuum measuring sphere - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose of the present invention is to provide a vacuum measuring sphere in which an electrode is enclosed in a metal tube and is not easily damaged. [Structure] An electrode is enclosed in a metal cylinder 2 via a glass sealing terminal 1. The glass sealed terminal 1 has a plurality of insertion holes 1 formed in a metal enclosure 10 having a cylindrical portion 14 formed on the periphery thereof.
0a is formed, and the plurality of lead-in wires 8 are airtightly attached to the different insertion holes 10a and are isolated from each other. Also,
A thin portion 15 is formed in an annular shape inside the edge of the tubular portion 14. The tubular portion 14 is fitted in the metal tube 2 and is fixed by welding.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 In this invention, an electrode of a vacuum measuring sphere was assembled on a glass sealed terminal and was welded to a metal tube.

[0002]

[Prior Art]

 Currently, hot cathode ionization vacuum measuring spheres are often used in which electrodes are assembled in a glass tube and one open end of the glass tube is connected to a vacuum device.

[0003]

[Problems to be solved by the device]

 This type of measuring sphere is easily broken because the tube is made of glass. If the glass tube is damaged by an external force when it is mounted on the device, the glass fragments will be sucked into the device and scattered, causing damage. An object of the present invention is to provide a vacuum measuring sphere in which an electrode is enclosed in a metal tube and is not easily damaged.

[0004]

[Means for Solving the Problems]

 The vacuum measuring sphere of the present invention which achieves the above object is a vacuum measuring sphere in which an electrode is enclosed in a metal cylinder through a glass sealed terminal, and the glass sealed terminal has a cylindrical portion at its periphery. A plurality of insertion holes are formed in the formed metal enclosure tray, and a plurality of lead-in wires are airtightly sealed in different insertion holes and are isolated from each other, and are inside the end of the tubular portion. It is characterized in that the thin portion is formed in an annular shape, and the tubular portion is fitted into the metal tube and fixed by welding.

At least one lead wire hermetically sealed to the glass sealed terminal is connected to the enclosing tray so that a ground potential can be applied to the encapsulating tray and the metal cylinder through the lead wire. Is desirable.

[0006]

According to the vacuum measuring sphere of the present invention, it is possible to construct a vacuum measuring sphere that is not damaged even when an external force is inadvertently applied.

[0007]

【Example】

 FIG. 1 is an example to which the present invention is applied. FIG. 2 is a sectional view taken along the line AA of FIG. The electrodes of a BA vacuum gauge, which is a type of hot cathode ionization vacuum gauge, are incorporated. In the figure, 1 is a glass sealed terminal, and 2 is a metal tube. The glass sealing terminal 1 is assembled with the grid 3, the two filaments 4, 5, the collector 6 and the collector shield 7 through the lead-in wire 8 of the glass sealing terminal. One lead-in wire 8 of the glass sealed terminal 1 is connected to a terminal enclosing tray 10 by a connecting wire 9. The metal tube 2 is welded to the glass sealed terminal 1 at one end 11. A connecting pipe 12 is provided at the other end. A ground potential is applied to the metal tube 2 and the enclosing tray 10 by the introduction line 8. In the BA type vacuum gauge, it is important to determine the potential of the container.

FIG. 3 shows a vertical cross section of the glass sealed terminal 1. FIG. 4 is a partially enlarged sectional view of the peripheral portion. The plurality of introducing wires 8 are hermetically sealed to the enclosing tray 10 with glass 13. Since the respective introduction lines 8 are airtightly sealed and isolated from the different insertion holes 10a, 10a of the common enclosure 10 respectively, there is no mutual interference of DC electric signals. This is important for the collector of a BA type gauge.

The enclosing tray 10 of the glass sealed terminal 1 is formed by pressing a plate. The peripheral tubular portion 14 of the enclosing tray 10 is fitted into the metal tube 2 and welded. A thin-walled portion 15 in which the wall thickness of the sealing tray is thin is provided in an annular shape at a portion slightly inward of the edge of the peripheral tubular portion 14. This thin portion 15 prevents distortion of the welded portion from being transmitted to the glass sealing portion of the lead-in wire 8. In a sealed pan that does not have a thinned portion, the glass sealing part may be damaged by the strain during welding.

FIG. 5 shows another example to which the present invention is applied. A flange 16 is provided in place of the connecting pipe 12 in FIG. 1, and can be connected to a vacuum device via the flange 16. In this form, the exhaust conductance of the connection is large, so the measurement error can be reduced.

There is a conventional vacuum measuring sphere in which an electrode is assembled to a glass sealed terminal and which is enclosed in a metal tube. A Pirani type vacuum gauge is one example. In this case, the glass sealed terminal is soldered to the metal tube. Solder sealing is not suitable for hot cathode ionization vacuum gauges in terms of gas release. One of the features of the present invention is to weld the glass sealed terminal to the metal tube by welding.

There is a vacuum measuring sphere that uses a terminal in which a glass is sealed in an enclosure dish and a plurality of wires are introduced therein. In the present invention, a plurality of lead-in wires are provided separately by airtightly sealing the different insertion holes. This difference is important. The volume of the glass part is made smaller by separating them with different insertion holes. The smaller volume of the glass part is advantageous in terms of breakage.

There is a vacuum measuring sphere in which glass is sealed in a metal tube and a plurality of monopolar glass terminals in which a single wire is introduced are welded to a plurality of flanges. The present invention encloses a plurality of conducting wires in a single enclosing tray, which can be made small in size and is advantageous in terms of manufacturing cost.

Although the B-A type ionization vacuum gauge has been described as an application example, the present invention is not limited to this and can be applied to other types of vacuum measuring spheres.

[0015]

[Effect of the device]

 As described above, according to this invention, there is an effect that it is possible to provide a robust vacuum measuring sphere that is not damaged even if an inadvertent external force is applied.

[0016] Furthermore, in particular, since the enclosure plate of the glass sealed terminal and the metal tube are fixed by welding, there is an effect that a vacuum measuring sphere with less gas emission can be provided, and it is adjacent to the welded part of the enclosure plate. Since the thin annular portion is formed, there is an effect that it is possible to provide a vacuum measuring sphere that is not damaged by welding strain.

Furthermore, since the plurality of lead-in wires of the glass sealed terminal are isolated by airtightly sealing them in different insertion holes in the common enclosure tray, the volume of the glass of the sealed terminal can be reduced and the terminal can be made smaller. There is an effect that it is possible to provide a vacuum measuring sphere with a strengthened portion, and to provide a small and inexpensive vacuum measuring sphere.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a BA type ionization vacuum gauge measuring sphere according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged sectional view taken along line BB of FIG.

FIG. 4 is a partially enlarged sectional view of FIG.

FIG. 5 is a partially cutaway front view of a vacuum measuring sphere according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass-sealed terminal 2 Metal tube 8 Introducing wire 9 Connecting wire 10 Encapsulation dish 10a Insertion hole 13 Glass 14 Peripheral tubular portion 15 Thin portion

Claims (2)

[Scope of utility model registration request] 1. A vacuum measuring sphere in which an electrode is enclosed in a metal cylinder through a glass sealed terminal, wherein the glass sealed terminal is a metal enclosure dish having a cylindrical portion formed on a peripheral edge thereof. , A plurality of insertion holes are formed, and a plurality of introduction lines are airtightly sealed in different insertion holes, respectively, and are separated from each other, and a thin portion is formed annularly inside the end edge of the tubular portion. The vacuum measuring sphere is characterized in that the tubular portion is fitted in a metal tube and is fixed by welding. 2. The vacuum measuring sphere according to claim 1, wherein at least one lead-in wire hermetically sealed to the glass-sealed terminal is connected to the enclosing tray.