JPS5884692A - Detector for weld line in electron beam welding - Google Patents

Abstract

PURPOSE:To prevent melting of work pieces by investigating the AC current flowing in a deflecting coil disposed in the irradiating route for an electron beam and making the relation between the joint positions of the work pieces and the position of the electron beam detectable. CONSTITUTION:A titled device consisting of a zero point detecting section 15 for detecting the zero point of the AC current flowing in a polarizing coil 6, a collector 8 for detecting the secondary energy 9 generated by collision of an electron beam 3 and work pieces 4, and an oscilloscope 13. Said coil 6 is disposed in the irradiating route of the beam 3 which is so controlled as to scan across the joint 7 of the work pieces 4. Said oscilloscope 13 compares the point where the detected value of the secondary energy 9 is minimum with the detection signal for zero point from the detection section 15 and detects the position relation of the beam 3 with the joint 7 of the work pieces 4. The melting of the work pieces is prevented by the above-mentioned device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bath tangent detection device in electron beam bath contact for detecting the position of a cut in a work piece and the sound of the positional relationship with the electron beam, except when performing electron beam welding. It is something.

In the past, there was a device shown in FIG. 1 (V()). In the figure, l is a high 11-pin piezoelectric cylinder, ko is a '-child gun, 3 is an electron beam, da is a processed piece, S is a 'kameko gik',
The electron beam 3 generated by 2j is directed to the entrance surface of the workpiece l by the Toto coil, 6 is the force 11 of the workpiece l, and the deflection is made to scan the electron beam 3 across the difficulty 7. The coil is a collector that captures reflected electrons and secondary electrons 9, /θ is a signal generator, // is a waveform converter, /ko is a waveform converter that stamps No. 1d from // into the deflection coil B. No-good current product! 1 (2 is a resistor, /
3 is an oscilloscope, and /g is a bright spot appearing on the screen of OFF 0 Scono/3.

Next, the operation will be explained. In Fig. 1, the output of the signal generator 10 is manually amplified by a waveform converter///2 to a current amplifier/2, and is amplified to a constant size of 7J+, and is then supplied to the deflection coil B. , the signal from both ends of resistor R1 is the horizontal axis deflection terminal of onroscope /3 /3a$- and /,
? B is manually operated. On the other hand, the force 11 from the focusing coil s vC
The electron beam 3 that was delivered to the workpiece was turned on by the above-mentioned deflection coil (1).

Also, '..., the reflected electrons 1) and secondary electrons of the child beam 3 are captured by the collector? Vertical IKiI deflection of Σre oscilloscope/3! It is input to H11 child /3C, and /, and node d. The signal generator 10 outputs a triangular waveform signal, and this signal is converted into the waveform shown in FIG. 2 by a waveform converter/l. In the waveform shown in FIG. 2, each voltage zero point is at a time .tau.=+, which is an extension of 1 time t'l. As a result, when the beam 3 is at a point where it is not surveyed, that is, the beam is on the seam 7, on the Onroscope/3, when the Tonta waveform is in the figure, IMiτ stops opening, so the screen V (
A bright spot/da will occur. Therefore, by utilizing the characteristic that the amount of backscattered electrons and secondary electrons reaching the collector g decreases in the order of force 11 and piece joint 7,
By aligning the peak point of the signal decrease with the peak point of the collector signal, positioning can be achieved.

However, in the conventional bath tangent detection device, the electron beam hits a point where it is not deflected t'L and stops for a travel time τ, which has the disadvantage that the work piece is easily melted. If the electron beam flow rate is made small in order to prevent There were disadvantages such as being limited to only when .

This invention was made in order to eliminate the drawbacks of the conventional ones as described above. Instead of waveform conversion 11 + By providing a means for detecting the point), the joint position of the processed pieces and the position of the beam irradiation can be accurately positioned, thereby preventing the electron beam bath from melting the piece. An object of the present invention is to provide a bath tangent detection device in a bath.

An embodiment of the present invention will be described with reference to FIG. In Fig. 3, (g generator lθ and current amplifier/
The waveform conversion g / / has been removed from between 2 and 2, and in its place, a zero point detection section /S for detecting the zero point of the input signal to the deflection coil 6 is installed at both ends of the resistor 1 (1). The output of the zero point output section/S is provided with a pulse generating section 16 for generating a pulse generating section corresponding to the signal from the zero point detecting section/S. is provided,
The output side of the pulse generator /6 is connected to the brightness modulation input terminals /Je and /3fVC of the oscilloscope 13.

Note that the other configurations are the same as those in FIG. 7, so explanations will be omitted.

Next, the operation will be explained. In FIG. 3, a signal having the same phase as the magnetic current passing through and away from the deflection coil t, that is, a signal corresponding to the scanning of the electron beam 3, is obtained at both ends of the resistor R1. are the horizontal axis deflection terminals /3a and /, ? of the oscilloscope 13. When connected to b, both VC
'4 point detection capital 13Vc is also input. The output from the zero point detection section 15 is converted into a pulse voltage by the pulse generation section /b, and is applied to the brightness modulation input terminals /3e and /3f VC input terminals of the onroscope /3. This terminal /3e and /3
The pulse voltage input to f represents the point at which the electron beam 3 is unavoidably deflected.

On the other hand, the signal from the collector L and the signal from the resistor R2's V is turned off at the vertical axis deflection terminal of the scope/3.
,3C,and/,? Input to d. As mentioned above, the backscattered electrons and secondary electrons q decrease at the force 11 piece joint position 7, so by using this characteristic phenomenon, the vertical axis of the on-screen VC of Onrosf-7''/J is reduced. By matching the point at which the change in the electron beam reaches its peak with the brightness): (/da), the electron beam () can be directed to the force 11 piece joint position 7 with good precision.

In addition, in the above actual example, the output of the pulse generation 11μ/6 is inputted to the brightness 11j modulation input terminals /3θ and /3f of the oscilloscope 13, and a bright spot l appears on the scope screen.
However, as shown in Figure VC, the output of the pulse generator/A and the input voltage from the collector are included. death,
C、ノJJf+W 器／? Output 'a= iiJ
VCt, but in this case, the oscilloscope 13 is connected to 71 as shown in Figure 3'.
．． ↓ Instead of a bright spot, a chama waveform/ni will appear.

In addition, even if X-rays are used as the detection means instead of reflection '1 mu f-sons and secondary/electrons, the basic VC('') will change.7'J
: <A similar effect.

As described above, by this emission ψ, the point where the electron beam is not deflected is electrically detected, a pulse voltage is generated at this detection point, and a rigid force is applied to the onoposcope luminance input terminal. 11, the bath tangent can be detected without delaying the electron beam time, reducing problems caused by bath melting of the workpiece, and selecting the thermal location of the workpiece. This has the effect of expanding the range.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional weld line detection device.
FIG. 2 is a waveform diagram that explains the operation of FIG. 1;
Fig. 3 is a block diagram showing a welding line detection device according to an embodiment of this invention, Fig. 9 is a block diagram showing another embodiment of the invention, and Figs. FIG. 3 is a diagram showing a waveform appearing on an oscilloscope plane VC. In the diagram VCj, 3 is the child beam, da is the workpiece, y is the focusing coil, tk is the deflection coil, 7 is the joint, g is the collector, 91 reflected 1st beam and secondary electron, ゛also t, i X
&+ (secondary energy), 10 is the signal generator, /2 and 1
'Tun 61L amplifier, /,? is an oscilloscope, /3a and / , 7 tl l, horizontal axis deflection terminal, /3CL
- and /3d striped 1mm axis deflection terminal, /3e and /,
3ff maj4f Mc K 1t14 input terminal, /S is zero point detection section, /lf ma pulse generation) 11 (, /7 is jJ
It's a ll m device. In addition, the same reference numerals in the drawings indicate the same parts corresponding to the same and -Tsuda Q1. Agent Kano 1r3 −

Claims (1)

[Claims] tl) The electron beam is caused to travel across the seam of the work piece by passing an alternating current through a deflection coil disposed in the irradiation path of the electron beam. In beam bath contact, a zero point detection unit detects the zero point of the ojj alternating current, and the collision of the electron beam with the workpiece)
By using a collector for detecting the generated secondary energy and comparing the minimum point of the secondary energy detection 111 from the collector with the zero point detection signal from the zero point detection section, it is possible to detect the seam of the work piece. 1. A bath contact edge detection device for electron beam bath contact, characterized by comprising means capable of detecting a position and a positional relationship between the electron beam and the electron beam. (2) The bath contact edge detection device for electron beam bath contact according to claim 7, wherein the means for positional relationship detection iJ bait is an Onroscog. (The secondary energy detection value from the 31MJ gorector is manually applied to the vertical axis deflection terminal of the oscilloscope, and the signal from the zero point detection section is converted into a pulse corresponding to the zero point. The bath tangent detection device in the electron beam bath tangent yc described in the first item. (4) The secondary energy detection value from the collector and the pulse VC conversion extended signal from the zero point detection section are superimposed by an adder and input to the off-zero scope. A bath contact detection device for electron beam welding according to item 2. (5) A bath tangent detection device for electron beam bath tangent according to any one of claims 1 to q, wherein the alternating current flowing through the deflection coil /l/vC is a triangular wave current.