JPH0449079B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray detector for a welding line detection device, and more specifically, during electron beam welding, a scanning electron beam is irradiated onto a welding line of a workpiece to be welded. The present invention relates to an X-ray detector in a welding line detection device for detecting X-rays emitted from an irradiation position and accurately positioning an electron beam at a welding line.

Conventionally, there has been an X-ray detector of this type as shown in FIG.

In the figure, arrow 1 indicates X-rays emitted from the electron beam irradiation position of the workpiece. The X-ray detector includes a shielding plate 3 made of metal foil that transmits only X-rays and blocks radiation noise such as reflected electrons, secondary electrons, and light at the open end of a metal container 2, and a photodiode inside the metal container 2. , an X-ray detection element 4 made of a semiconductor photodetection element such as a phototransistor is housed and arranged.

The terminal 5 led out from the X-ray detection element 4 is supported by an insulating support plate 6 coupled to the inner opening of the metal container 2 and led out inward, and is connected to the core wire 8 of the shielded wire 7 and the terminal connection part 9. connected with. The terminal connection portion 9 is shielded by an electrically shielding metal foil 10.

With such a configuration, the X-rays 1 emitted from the electron beam irradiation position of the workpiece pass through the shielding plate 3 that blocks reflected electrons, secondary electrons, and light, enter the X-ray detection element 4, and are detected by the X-rays. The line detection element 4 converts it into a signal current. This current signal is transmitted to an appropriate signal processing and display device via a shielded wire 7.

However, the conventional X-ray detector having the above configuration has various problems.

That is, when metal vapor generated during electron beam welding forms a vapor deposited layer on the shielding plate 3, the amount of X-rays passing through the shielding plate 3 decreases, and the measurement sensitivity apparently decreases.

Therefore, in order to recover the measurement sensitivity, it is necessary to
It is necessary to remove the vapor deposited layer formed on the shielding plate 3, but in order to remove the vapor deposited layer without damaging the shielding plate 3, special means such as etching must be used.
In addition, since the terminal connection part 9 is joined by soldering etc., it is not easy to attach or remove it from the shield wire 7 in a narrow space, and the electrical shielding effect of the terminal connection part 9 by the electrical shielding metal foil 10 is incomplete. It happened that it happened.

Furthermore, there were many drawbacks, such as difficulty in maintenance and management because the shielding plate 3 was easily damaged.

This invention was made in view of the above circumstances, and by assembling and configuring an X-ray detector and a coaxial connector as one unit, it is possible to easily attach and detach the shielded wire and completely eliminate the electric shield. Furthermore, the shielding plate part of the X-ray detector is molded with resin, and a cover made of a resin material with low X-ray absorption is attached to the outer periphery of the resin mold. It is an object of the present invention to provide an X-ray detector for a weld line detection device that can prevent damage to the plate, reduce maintenance costs, and improve the operating rate of the weld line detection device.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, a coaxial connector 20 has a coaxial terminal 22 supported by a metal outer cylinder 21 via an insulator 23, and a metal container 2 containing an X-ray detection element 4 is coupled to the coaxial connector 20.

That is, the metal container 2 is attached to the lower end opening of the outer cylinder 21.
The upper end portions of the two are fitted and connected at the joint portion 24. Therefore, the coaxial connector 20 is of a non-sealed type. The terminal 5 of the X-ray detector 4 is supported by an insulating support plate 6 and led out, and is connected to the outer cylinder 21 at joints 25 and 26.
They are respectively connected to coaxial terminals 22 . A resin mold 27 is applied to the outer surface of the shielding plate 3 to protect it.

Next, we will discuss the effects.

In this embodiment, the X-ray detector element 4 is surrounded by a coaxial connector 20, a metal container 2, a shielding plate 3 made of metal foil, etc. Therefore, the shielding plate 3 for shielding radiation noise such as light is provided. It responds only to the transmitted X-rays and converts them into electrical signals.

This electrical signal is transmitted from the coaxial connector 20 via the coaxial cable to the signal processing device in a completely electrically shielded state, so even if the electrical signal is minute, it can be extracted with a high S/N ratio (signal-to-noise ratio). be able to.

In addition, even if a sudden leak occurs from the X-ray detector during welding and the vacuum pressure rises rapidly, the coaxial connector 20 is non-sealed, so it will not remain in the connector part. Since the gas can be easily evacuated, deterioration of welding quality can be prevented. Furthermore, even if a vapor deposited layer is formed by metal vapor generated from the welding part during electron beam welding and the X-ray transmittance of the shielding plate 3 decreases, the X-ray detector including the shielding plate 3 is Since it can be removed from the coaxial cable at the same time, the vapor deposited layer can be easily removed with a tool such as a file after being removed. Moreover, in this case, since the shielding plate 3 is protected by the resin 27, it will not be damaged even if a tool such as a file is used.

Furthermore, if a spare X-ray detector of the same type is prepared, the welding line detection device only needs to be stopped for the time required to replace the coaxial connector, thereby increasing the operating rate of the device.

As is well known, in electron beam welding, molten metal may be scattered from the welding location during welding, and this scattered metal (hereinafter simply referred to as spatter) may spread to the resin 27 that protects the shielding plate 3 that constitutes the X-ray detector. In addition to simply adhering to the surface of the resin 27, it may melt and bite into the resin 27.

Therefore, after removing the spatter, the resin 27
Leaves uneven marks on the surface. In addition, the metal vapor generated during welding adheres to the entire surface including the uneven parts, so in order to remove the deposited layer of metal vapor with a file etc., it is necessary to check not only the thickness of the deposited layer of metal vapor. It becomes necessary to scrape off excess resin 27 to the depth of the uneven portion.

Therefore, it is inevitable that the number of times the protective layer formed by the resin 27 can be scraped off will be significantly reduced.

In the above embodiment, the shielding plate 3 is molded with resin 27, but as in another embodiment shown in FIG. By providing a configuration in which 28 is attached, the above effects can be further enhanced.

With this configuration, even if the cover 28 is damaged by spatter and the cover 28 becomes uneven, only the cover 28 will be damaged, and the resin 27 for protecting the shielding plate 3 will be damaged. Since spatter or metal vapor does not directly adhere to the resin 27, the thickness of the resin 27 does not need to be increased more than necessary.

In addition, since this cover 28 is attached to the outside of the resin 27 in a detachable and replaceable manner, the cover 28
8 can be easily replaced. Therefore, it becomes easy to recover the detection sensitivity decreased by metal vapor.

As described above, according to the present invention, (a) only the cover can be replaced, so the X-ray detector can be installed even in a narrow place where it is relatively difficult to attach and detach the coaxial cable.

(b) According to (a), there is no need to provide a special space in advance for replacing the X-ray detector, so the installation space can be reduced and the effective use of the welding chamber space of the electron beam welding device can be increased.

(c) Since the detection sensitivity can be easily restored by simply replacing the cover, it is possible to eliminate the work of removing the deposit layer using metal vapor using a file or the like.

(d) (c) Not only can the operating rate of the weld line detection device be improved, but also maintenance time can be shortened.

(e) By (d), maintenance management personnel costs can be reduced.

There are other effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional device, FIG. 2 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of an embodiment of the same distinction. 1...X-ray, 2...metal container, 3...shielding plate,
4...X-ray detection element, 5...Terminal, 6...Insulating support plate, 20...Coaxial connector, 21...Outer cylinder, 2
2... Coaxial terminal, 23... Insulator, 24, 25,
26... Connection portion, 27... Resin, 28... Cover. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In an X-ray detector that detects the X-rays emitted when a scanning electron beam crosses the welding line of the workpiece during electron beam welding, only the X-rays are transmitted through an opening at one end, and other radiation noise is not detected. A metal container having a shielding plate and housing an X-ray detection element, a coaxial connector having a metal outer cylinder opening connected to the other end of the metal container, a resin mold layer being provided on the outer surface of the shielding plate, and An X-ray detector for a welding line detection device, comprising a removable cover that covers the shielding plate and the vicinity of the end of the metal container on the side where the shielding plate is provided.