JPS6352782A - Electron beam welding machine - Google Patents

Abstract

PURPOSE:To prolong the service life of a cathode and to prevent the occurrence of the arcing by providing the negative electric potential and the pressure lower than that of a welding chamber to an object to be welded on a path part of an electron beam in the welding chamber and providing a chamber provided with orifices to a boundary part with the welding chamber. CONSTITUTION:The chamber 21 with the pressure lower than that of the welding chamber 12 is provided and the negative electric potential is provided to the object 8 to be welded by a power source 22 in the chamber 21. Furthermore, the orifices 23 and 24 are provided to the upper and lower parts of the chamber 21 to maintain the chamber 21 to the pressure lower than that of the chamber 12 and not to prevent the path of the electron beam 2. Ionized gas and metallic vapor coming out from the object 8 to be welded enter the chamber 21 through the orifice 24 and the gas and vapor which strike against the wall surface are provided with the negative electric charge and neutralized and stuck to the wall surface or enter the chamber 21 by this constitution. However, since the molecular weight is larger than gaseous molecules, the gas and vapor hardly enter the chamber 21 and furthermore, since the pressure of the chamber 12 is higher than that of the chamber 21, even if the gas and vapor enter the chamber 21, these hardly come out from the orifice 23. Furthermore, the gas and vapor which are diffused in the chamber 21 strike against the wall surface, etc., and are apt to be neutralized and when neutralized, these are not accelerated and hardly come out from the orifice 23 more and more.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electron beam welding machine, and more particularly to an electron beam welding machine whose cathode life is extended.

[Conventional technology]

Figure 2 shows Mitsubishi Electric branch line vDL, j-4<A 3 ,
910P'1t-10 is a configuration diagram of an example of a conventional electron beam welding machine shown in FIG.

In the figure, the symbol (1) is the cathode for generating the electron beam (2), the symbol (3) is the cathode (1) for generating the electron beam (2), and the cathode (1) for accelerating the electron beam (, 2). (6) is the focal point of the electron beam (2), the first converging lens adjusts the angle of the electron beam entering the second converging lens, and A third converging lens (7) is used to align the electron beam (2) with the workpiece (g).
) A deflection lens that applies Vc, (9) is an electron gun chamber that creates a vacuum atmosphere for the cathode (1) and anode (ri), and (10) is an electron gun chamber for adjusting the differential pressure between the electron gun chamber (9) and the welding chamber. This is a differential pressure chamber, (//) is its orifice, and (/2) is a welding chamber for creating a vacuum atmosphere for the workpiece (g).

Next, the operation of this conventional device will be explained.

The electron beam (2) is generated by heating the cathode (1).

The generated electron beam (2) is accelerated between the cathode (1) and the anode (ll) by the high voltage power supply (3), and the anode (
Acceleration is output from the electron gun chamber (9) through the hole made in the electron gun chamber (9).

After that, the first convergence lens (!r) located in the differential pressure chamber (io)
The convergence angle is adjusted by the welding chamber (/, 2), and the convergence lens (6) in the welding chamber (/, 2) converges on the workpiece (ff) at an angle deflected by the deflection lens (7). By hitting r), kinetic energy is changed to thermal energy, melting the workpiece (f) and performing welding.

Note that in FIG. 2, arrows indicate evacuation by the evacuation device.

At that time, as shown in Fig. 3, a large amount of gas and metal vapor is generated by the object to be welded, which is ionized by the electron beam (2).
It is accelerated in the opposite way to 2) and hits the cathode (1).

As a result, the surface of the cathode (1) is consumed, and arcing and the like occur.

Next, the electron gun room (Te), the differential pressure room (10), the welding room (〆2
).

As mentioned above, the electron gun chamber (TE) is usually kept under a high vacuum, e.g. tX/0-jPa, in order to heat the cathode (1).
, 1ixt□−'艷rr, and −
The pressure in the welding chamber (l) is set to a level that does not cause the electron beam (l) to collide with gas molecules in the air and lose energy, for example, at a pressure of Pa1/X/0-' Torr or less. There is a need. Therefore, in order to use the welding chamber (/2) in a relatively high pressure state and the electron gun chamber (W) in a low pressure state, K is the differential pressure chamber (10
) and orifice (//) are required.

[Problem that the invention seeks to solve]

Since the conventional electron beam welding machine is configured as described above, the cathode must be replaced as it wears out, and there are also problems in that arcing occurs.

This invention was made to solve the above-mentioned problems, and aims to provide an electron beam welding machine that extends the life of the cathode and is less likely to cause arcing.

[Means for solving problems]

In the electron beam welding machine according to the present invention, a negative potential is applied to the workpiece to be welded to a part of the welding chamber corresponding to the path of the electron beam, and the pressure is lower than the pressure of the welding chamber,
A chamber with an orifice is provided in the electron beam path at the boundary with the welding chamber.

[Effect]

In the electron beam welding machine according to the present invention, the electron beam hits the workpiece in the welding chamber, and as a result, a large amount of ionized gas and metal vapor from the workpiece is negatively affected by the workpiece. , and is removed by the chamber at a pressure lower than that of the welding chamber, so that it does not impinge on the cathode located in the electron gun chamber.

〔Example〕

The present invention will be explained below based on the drawings showing one embodiment thereof.

In the wc1 diagram, the symbol (2/) is a chamber whose pressure is lower than that of the welding chamber (/2), and (1) is a chamber (2/) that gives a negative potential to the workpiece Cr'). The power supply for, (ko3) and (,2p) are the orifice of chamber (2/), (,
2) is an insulator that insulates the chamber (2/) and the welding chamber (/).

In addition, orifices (
23) (2g) is provided.

In addition, in other configurations, except that the converging lens (A) and the deflecting lens (W) are attached to the chamber (2/),
It has the same configuration as the conventional electron beam welding machine shown in FIG. Therefore, items indicated by reference numerals other than those described above are equivalent to those indicated by the same reference numerals in conventional electron beam welding machines.

Next, the operation of this embodiment will be explained.

The ionized gas and metal vapor from the workpiece (y) enter the chamber (2/) through the orifice (2) at the bottom of the chamber (2/). At this time, the gas and metal vapor that hit the wall of the chamber (21) are either given a negative charge and become neutralized, or are neutralized and left in the chamber (21). /) Enter k. However, since the molecular weight is thicker than gas molecules, it is difficult to detect (-2)〆), and the pressure in the chamber (,2/) makes welding g (/,2)
Because of the high ff force of , even if ~g (,2/)K enters, K << will come out from the upper orifice (,2,?).

Moreover, the amount diffused inside the room (2/) hits the wall surface, etc., and is easily neutralized. Therefore, when it is neutralized, it is no longer accelerated and it becomes increasingly difficult for it to come out from the upper orifice (23).

〔Effect of the invention〕

As described above, according to the present invention, a negative potential is applied to the workpiece to be welded to the part of the welding chamber of the electron beam welding machine that corresponds to the path of the electron beam, and the pressure is lower than the pressure of the welding chamber. Since the structure includes a chamber equipped with an orifice in the electron beam path at the boundary with the adjacent welding chamber, gas and metal vapor generated from the workpiece are prevented from advancing toward the cathode side by the chamber. First, it does not hit the cathode, and as a result, there is less wear on the surface of the cathode, which reduces the frequency of cathode replacement, and provides an electron beam welding machine that is less likely to cause arcing. are doing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an electron beam welding machine according to one embodiment of the present invention, FIG. 2 is a block diagram showing a conventional electron beam welding machine, and FIG. 3 is an explanatory diagram showing the principle of cathode consumption. (,2)...electron beam, (za)...workpiece, (//
). (,2,7), (,2g)...orifice, (/2
)...Welding room, (ko/)...Room, (,2,2)...Power supply. In each figure, the same reference numerals indicate the same or corresponding parts. Atsushi 1 Figure 2: Electric + Bee 8 ° Nene + 4 # thing 11.23.24: Orifice 12; Azusa chamber 21: Spirit 22: Power supply '7tf, 2 figure

Claims (1)

[Claims] The part of the welding chamber that corresponds to the path of the electron beam is given a negative potential with respect to the workpiece, and has a pressure lower than the pressure of the welding chamber, and the electron beam at the boundary with the adjacent welding chamber is An electron beam welding machine characterized by having a chamber provided with an orifice in the beam passage.