JPH0357573A - Electron beam working machine - Google Patents

Abstract

PURPOSE:To facilitate the work by correcting a work distance by utilizing a fact the spot diameter of an electron beam is varied by a variation of the work distance, and a detection waveform of a weld line detecting device becomes small suddenly except a prescribed work distance. CONSTITUTION:A memory contained driving device 15 drives an object 4 to be welded, and can vary a distance between an electron gun 2 and the object 4 to be welded, that is, a work distance. When a focus of an electron beam 3 is adjusted so that its spot diameter becomes smaller, it becomes sharp and the peak is large as a detection waveform 16c of an oscilloscope 13. In a middle position of welding, the focus of the electron beam 3 is shifted due to a set error of the object 4 to be welded and as for a detection waveform 17c, its peak becomes small. In this case, when the object 4 to be welded is moved so as to becomes as the detection waveform 16c, the work distance can be corrected to prescribed length. In such a way, both the detection of a weld line and the correction of the work distance can be executed, and the work can be executed easily.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention not only can detect machining lines when machining a large workpiece using an electron beam processing machine, particularly an electron beam, but also can detect machining lines using an electron gun. Distance of the workpiece (hereinafter referred to as work discance). ) is related to an electron beam processing machine that can maintain a constant value.

[Prior Art] Fig. 4 schematically shows an electron beam welding machine as a conventional electron beam processing machine having a device for detecting processing lines, such as welding lines, as disclosed in, for example, Japanese Patent Laid-Open No. 60-3985. It is an elliptical diagram.

In the figure, (1) is a high-voltage power supply with one end, for example, the ten terminal, grounded, (2) is an electron gun connected between both ends of this high-voltage power supply (1), and (3) is this electron gun (2). (4) is the workpiece to be processed by this electron beam (3), in this case the workpiece, and (5) is the electron gun.
The electron beam (3) generated by the electron gun (2) is placed between the object to be welded (4) and the object to be welded (4).
A focusing coil (6) is placed between the focusing coil (5) and the object to be welded (4) to direct the electron beam (3) onto the surface of the object to be welded (4), e.g. A deflection coil (8) for scanning the electron beam (3) across the welding line (7) is placed between the deflection coil (6) and the workpiece (4) to scan the electron beam (3) across the welding line (7). 3) a collector as a sensor that captures the reflected electrons and secondary electrons (9); (10) is a signal generator; (11) is a waveform converter connected to the output of the signal generator (10); (I
2) is a current amplifier connected between this waveform converter (I1) and the deflection coil (6), and R1 is this current amplifier (12).
) and the deflection coil (6), R2 is the resistor connected between the collector (8) and ground, (1
3) are horizontal axis deflection terminals (13a) (13b) connected to each end of resistor R1, and vertical axis deflection terminals (13c) connected to each end of resistor R2, respectively.
．． An oscilloscope having (13d) and constituting a welding line detection device together with the collector (8), <14) is a bright spot appearing on the screen of this oscilloscope (13).

A conventional electron beam welding machine is constructed as described above, and its operation will be explained in detail below.

In the electron beam welding machine shown in Fig. 4, a signal generator (10
) is input to the current amplifier (12) after being subjected to waveform conversion (described later) in the waveform conversion section (11>), where it is amplified to a predetermined size and then supplied to the deflection coil (6). At the same time, the signal across the resistor R1 is transmitted to the horizontal axis deflection terminal (13a) of the oscilloscope (13) and (
13b). On the other hand, the electron beam (3) focused on the surface of the workpiece (4) by the focusing coil (5) is transmitted to the welding line (7) of the workpiece (4) by the deflection coil (6>).
) is scanned across.

In addition, the reflected electrons and secondary electrons (9) of the electron beam (3)
) is captured by the collector (8) and the signal across the resistor R2 is input to the vertical axis deflection terminals (13c) and (13d) of the oscilloscope (13). The signal generator (10) outputs a triangular waveform signal, and this signal is converted into a waveform as shown in FIG. 5 by a waveform converter (11). The waveform shown in FIG. 5 shows that each voltage zero point is for a time t,
It's stretched out. As a result, the point where the electron beam (3) is not deflected, that is, the point where the electron beam (3) is
), the voltage waveform on the oscilloscope (13) stops for the time t in Figure 5, and a bright spot (l4) appears on the screen.Therefore, reflected electrons and secondary electrons (9) reaching the collector (8) is the welding line (
Using the feature that decreases at the position of bright spot (14)
> and the peak point of the signal decrease from the collector 8), positioning will be achieved.

[Problem to be solved by the invention] Conventional electron beam processing machines can detect processing lines, but when the workpiece is a large structure, it is difficult to set the workpiece accurately and keep the work distance constant. The problem was that it could not be maintained.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to provide an electron beam processing machine that can not only detect processing lines but also maintain a constant work distance.

[Means for Solving the Problems #4] The electron beam processing machine according to the present invention is provided with a memory built-in drive device that drives at least one of the electron beam generating means and the workpiece.

[Function] The workpiece discance correction in this invention utilizes the fact that the spot diameter of the electron beam changes with a change in the workpiece discance, and the detection waveform of the welding line detection device suddenly becomes smaller outside of a predetermined work distance. and correct the work distance.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 1 showing the schematic configuration of this embodiment, (1) to (
14) is exactly the same as that in the conventional example. (15
) is a memory built-in drive device that drives the workpiece (4), and can change the distance between the electron gun (2) and the workpiece (4), that is, the work distance.

The electron beam processing machine, such as the electron beam welding machine, of the present invention is constructed as described above, and its operation will be explained in detail below.

6 Figure 2 is a diagram showing the relationship between the workpiece and the electron gun.
The figure is a diagram showing the relationship between work distance and detected waveform. As shown by the reference numeral (16b) in FIG. 2, it is extremely difficult to set a large workpiece (4) horizontally with respect to the welding direction.

The welding starting point can be adjusted to a predetermined work distance (16a), and if the electron beam (3) is focused so that its spot diameter is the smallest, the detected waveform of the oscilloscope (13) will be as shown in (16c). sharp and large peaks. On the other hand, at the welding intermediate position, the workpiece (4
> Due to the setting error, the work distance is (17a
), the electron beam (3) becomes defocused on the object to be welded (4), the spot diameter becomes large, and the detected waveform has a small peak as shown in (17c).

At this time, the work distance can be corrected to a predetermined length by moving the workpiece (4>) so that the detected waveform becomes as shown in (16c) again.

(17b) is the corrected position of the workpiece (4).

This correction amount (the amount of movement of the workpiece) is stored in advance in the memory built into the drive device (15〉7) and played back during welding so that the drive device (15) always maintains a predetermined work distance. It becomes possible to weld the workpiece (4) with the electron beam (3) while driving the workpiece (4).

In the above embodiment, the present invention is applied to an electron beam welding machine, but the present invention may also be applied to other applications other than welding, such as cutting.

Further, in the above embodiment, the object to be welded was moved by a drive device, but the same effect as in the above embodiment can be obtained even if the electron gun or both of them are moved. Furthermore, even if an X-ray sensor is used instead of the collector, the same effects as in the above embodiment can be obtained.

[Effects of the Invention] As described above, the present invention includes a drive device with a built-in memory that drives at least one of the electron beam generating means and the workpiece, and detects that the detection waveform of the welding line detection device changes depending on the work distance. Since the work distance is corrected using the same device, the same device can detect the weld line and correct the work distance, making the device less expensive, and eliminating the need to accurately set large workpieces, making the work much easier. It has the effect of

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an electron beam welding machine according to the present invention, FIG. 2 is a diagram showing the relationship between the workpiece and the electron gun, and FIG. 3 is a diagram showing the relationship between the work distance and the detected waveform. FIG. 4 is a schematic configuration diagram showing a conventional electron beam welding machine, and FIG. 5 is a waveform diagram showing the voltage of a waveform converting section. In the figure, (2) is an electron gun, (3) is an electron beam, (
4) is the object to be welded, (5) is the focusing coil, <6> is the deflection coil, <7) is the welding wire, (8) is the collector, <9> is the reflected electron or secondary electron, (13> is the oscilloscope) ,(
15) is a memory built-in drive device. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) an electron beam generating means for generating an electron beam for processing a workpiece; an electron beam generating means disposed between the electron beam generating means and the workpiece; and focusing the electron beam on the workpiece; a focusing/deflecting means for scanning the electron beam across the machining line of the workpiece; a focusing/deflecting means disposed between the focusing/deflecting means and the workpiece; a processed line detection device that detects the processed line by capturing reflected electrons or secondary electrons;
A drive device with a built-in memory that drives at least one of the electron beam generating means and the workpiece is provided, and when detecting a machining line, the electron beam generating means and the workpiece are connected between the electron gun and the workpiece from a machining start point to a machining end point. The method is characterized in that a distance correction amount from a predetermined value is detected and stored in the memory in advance, and during processing, the correction amount is played back and the workpiece is processed while maintaining the predetermined value. Electron beam processing machine.