JPS61283471A - Method and device for profiling weld line in electron beam welding - Google Patents

Abstract

PURPOSE:To perform in safe and highly reliable state the weld line detecting operation under welding by performing the weld line detecting operation only at the reduction time of the electron beam output. CONSTITUTION:The command to reduce the output of an electron beam 3 for the short period in the degree of not affecting on the welding quality in the output control part 1 is placed during the electron beam welding. The beam current is abruptly reduced corresponding thereto and a trigger pulse signal is outputted to a scanning signal generating part 7 simultaneously therewith from the output control part 1. By this pulse signal a scanning signal is transmitted to a deflection coil 6 from the scanning signal generating part 7 and the electron beam 3 is scanned at the front part of the welding zone. The weld line profiling operation is performed in the same procedure as the conventional technique thereafter. The melting and scanning trace on the surface of the body to be welded due to the beam scan are sharply reduced, the signal ratio to noise of the electrical signal by secondary energy is increased and the weld line profiling operation is stably performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention detects a weld line of a workpiece that emits carbon during welding, and detects the weld line of a workpiece that emit carbon during welding. Line tracing method and device S
This is related to two things.

[Conventional technology]

Fig. 3 is a schematic configuration diagram showing a conventional welding line tracing device. In Fig. CN, (1) shows an electron beam (3
), and (2) is an output control unit that controls this output control unit (1
) at a predetermined output and convergence position (= beam generator that emits the electron beam (3), (4) is the object to be welded, (5) is the welding line, and (6) is the deflection coil) (7) is the scanning signal generator, which is the deflection coil (6)
(=Sending a scanning signal and moving the electron beam (3) to the welding line (5)
A direction that crosses the! - deflect; (8) is the secondary energy released when the electron beam (3) collides with the object to be welded (4), and (9) captures this secondary energy (8) and converts it into an electric signal C2. Is this sensor αQ? (9) A welding line detection unit that compares the signal of (9) with the scanning signal and detects the welding line position.

Next, its operation will be explained. First, the output control section (1
)settings of! 21&Then, the electron beam (3) from the beam generator (2) is irradiated with a predetermined output at a convergent position on the workpiece (4). By moving this object to be welded (4) by a traveling truck or the like in one direction of the arrow ≦2, normal welding is performed along the welding line (5).

During such welding, the deflection coil tv (6) c current is supplied from the scanning signal generator (7) (see Fig. 4B).
be done. Here, the currents oo and (7) are applied to the welding ζ: The electron beam (3) is constantly scanned in front of the welding part at a high speed that has no effect, and the welding line (5) of the workpiece (4) is ) is deflected in a direction across the electron beam (3).

At this time, the surface of the workpiece (4) is exposed to two
Next energy (8) is released. This secondary energy (8
) is captured by the sensor f(9), but as shown in FIG. Secondary energy (
8) Data output corresponding to the change point (see Figure 4 E)C
Second, the current change in the deflection coil (6) is read by a welding line detection member, and the deviation from position 1 (a certain current position) ahead by a predetermined distance is determined. Then, the scanning signal generator (7) ζ: is sent out from the welding line detection member with a delay of a time corresponding to the moving speed C of the workpiece (4), and then the deflection coil (6) 12 The correction current of (i) is supplied to achieve pattern welding.

[Problem that the invention seeks to solve]

Since the conventional welding line tracing device is configured as described above, the welding line detection operation is performed eight times while the output of the electron beam remains at a high level. Therefore, during the detection operation, the workpiece may melt, or the spot diameter of the electron beam may be large (
This results in a decrease in the signal-to-noise ratio of the secondary energy signal since there is usually a proportional relationship C2 between the beam output and the spot diameter. For this reason, conventional profiling equipment (- indicates a factor that causes serious defects such as weld opening misalignment).

This invention was made to eliminate the above-mentioned factors, and aims to provide a profiling device that can safely and reliably detect weld lines during welding. .

[Means for solving problems]

The welding line tracing device according to the present invention sends a command to reduce the beam current for an extremely short period of time from the output control section to the beam generation section, and generates a trigger signal during the period when the beam current is decreasing. The weld line detection operation is performed in response to the beam scanning signal synchronized with the trigger signal C.

[For production]

The welding line tracing device according to the eighth aspect of the present invention reduces the electron beam output for a short period of time during the welding line detection operation, and prevents melting of the object to be welded by the scanning beam section.

This greatly reduces surface scratches and reduces the electron beam spot diameter.

[Embodiments of the invention]

Hereinafter, a weld line tracing device according to an embodiment of the present invention will be explained with reference to the schematic configuration diagram of FIG. Figure 1 (smells,
(b) is the moment when the beam output from the beam generation section (2) is reduced by the control signal from the output control section (1) - the trigger that is sent out at two speeds by the scanning signal generation section (7) C with two windows This is the signal lead wire. The other parts are the same as those explained in FIG. 3 above.

Therefore, the operation of FIG. 1 will be explained using the waveform diagram of each part shown in FIG. 1
) (=, a command is issued to reduce the output of the electron beam (3) for a short period of time that does not affect the welding quality C (see enlarged sections of AN and B in Figure 2).Then, the beam current changes accordingly. The output control section (1) synchronizes with this and rapidly (= decreases 6:) the scanning signal generation section (7).
) (Nitoriga pulse signal is output (see Figure 2 C). This pulse signal (=Therefore, the scanning signal generator (force deflects the coil/l/ (6) l Two scanning signals (3) and (1) are sent out. Then, the electron beam (3) is scanned in front of the welding area.The following procedure is similar to that of the prior art!The welding line tracing operation is achieved from the second step.

In the above embodiment, the case where the scanning signal was scanned in a triangular shape forward of the welding line was explained for simplicity, but it may be circular. Furthermore, although a single cycle is shown, even if it is a continuous cycle, the same effects as in the above embodiments can be obtained.

Furthermore, as a means for correcting the relative position between the electron beam irradiation position and the welding line position, we have explained the beam deflection 6:. Exactly the same effect can be obtained by feeding it back to the drive system of the object to be welded.

〔Effect of the invention〕

As described above, according to the present invention, the welding line detection operation is performed only when the electron beam output decreases, so it is possible to significantly reduce melting of the surface of the workpiece and scanning marks caused by beam scanning. At the same time, it is possible to increase the signal-to-noise ratio of the electrical signal due to the secondary energy. Therefore, according to the present invention 1, there is an effect that the welding line tracing operation can be performed extremely stably.

[Brief explanation of drawings]

Figure 1 is an example of this invention! Fig. 2 is a waveform diagram for explaining its operation; Fig. 6 is a schematic diagram of a conventional weld line detection device; Fig. 4 is a schematic diagram of a conventional weld line tracing device;
The figure is a waveform diagram for explaining the operation. In the figure, (1) is the output control section, (2) is the beam generation section, (
3) is the electron beam, (4) is the object to be welded, (5) is the welding line, (6) is the deflection coil, (7) is the scanning signal generator, (8
) is the secondary energy ν, (9) is the sensor, (g) is the welding line detection section, and α°C is the lead wire for the trigger signal. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Patent Attorney Tadashi Sato Figure 1 8: 2 Aiko Yuki°- 11: Trigger 1 Yukigo Figure 2 Figure 3 Figure 4 Temporary M

Claims (2)

[Claims] (1) a step of generating a trigger signal when the electron beam output from the beam generating section is momentarily reduced; and a step of generating a scanning signal for deflecting the electron beam in response to the trigger signal generated here; It consists of a step of converting the secondary energy generated when the electron beam collides with the object to be welded into an electric signal, and a step of comparing the scanning signal and the sensor output signal to obtain the output signal. A welding line tracing method in electron beam welding, characterized in that the welding line position is detected only when the electron beam is instantaneously reduced, and the electron beam is made to follow the welding line position. (2) An electron beam generation unit that scans the surface of the workpiece in a plane, a sensor that captures secondary energy generated in response to the electron beam emitted from the electron beam generation unit to the workpiece, and the sensor. a welding line detection unit that discriminates the welding line position of the workpiece from the change point of the output signal sent from the welding line; and a welding line detection unit that discriminates the welding line position of the workpiece from the change point of the output signal sent from the welding line; and A welding line tracing device for electron beam welding, comprising means for correcting a relative position with respect to the line, and configured to synchronize a trigger signal when the electron beam output decreases with a welding line detection operation.