JPS58181489A - Electron beam deflector - Google Patents

Abstract

PURPOSE:To enable the movement of the position to be irradiated with an electron beam to a target position at a high speed and with high accuracy and to prevent the transient oscillation after the movement, by impressing the pulse voltage which moves the position to be irradiated with the electron beam and the voltage waveform corresponding to the locus of the scanning electron beam to deflection coils. CONSTITUTION:A titled device provided with deflection coils 8, 9 and a means which generates the voltage waveform for the scanning locus corresponding to the prescribed scanning locus and superposes the voltage pulses simultaneously or successively on the voltage waveform of the scanning locus. The coils 8, 9 receive the deflection currents 19, 20 for deflecting an electron beam 4 for welding and move the beam 4 so as to draw the prescribed scanning locus. The waveform difference of the voltage waveform for the scanning locus by the transient response of said currents 19, 20 is corrected by the above-described voltage pulses. The position to be irradiated of the beam 4 is moved at a high speed with high accuracy by the above-mentioned method, whereby the transient oscillation after the movement is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam deflection device for moving the irradiation position of the electron beam on the surface of an object to be irradiated from the current position to the target position at high speed and with high precision in an electron beam processing device. Melt.

As an example of this Olm device, an electron beam welding machine that performs in-process welding line detection shown in Figs. 1 to 1 will be described. Figure 1 shows an example of the configuration of an in-process weld line detection device for electron beam welding.
/ is the electron gun, ko is the object to be welded, 3r! Object to be welded - ○ Welding line, Hiroshi is the electron beam for welding (hereinafter referred to as welding electron beam), S is the scanning electron beam for detecting welding @3, 6 is the current irradiation position of the welding electron beam tt -The I-axis used as the origin, same as 7Fi! Coil in the X-axis direction to obtain the scanning electron beam 3, ttl-1 scanning electron beam jo! The locus (hereinafter simply referred to as the locus) of the irradiation position f (hereinafter referred to as the irradiation position), /l is the reflected electron and secondary electrons generated when the workpiece is irradiated with the scanning electron and -muj. Electrons or FiX rays (hereinafter referred to as backscattered electrons or FiX rays), l is a detector for backscattered electrons or FiX rays, /Jd detector/
d is a gate pulse generator that commands the welding line detection period, is is an X-axis scanning waveform generator,
14 is a Y-axis scanning waveform oscillator, /tfi X-axis scanning arcuate amplifier (hereinafter referred to as X-axis amplifier), /fri Y-axis scanning waveform amplifier (hereinafter referred to as !-axis amplifier), IYFi
X-axis deflection current, 20FiY @ deflection current 1.2/1-IX
@Detection resistor of the deflection cable (hereinafter referred to as X-axis detection resistor) 5
), here is Y41Il1gA internal current detection resistor (hereinafter referred to as Y-axis detection resistor), and Co3 starts operation tU by the output signal of gate pulse generator Lda,
A calculation device that calculates the amount of deviation of the welding line from the detection signal of the Ylliil direction current -〇 and the output signal of the amplifier is of the detector l, and 2Il is the motor drive signal based on the output signal of the calculation device J. Generated servo amplifier, KoS
1 is an electron gun drive device, and 6 is a drive device for the workpiece to be welded.

Figure 4 is an enlarged view of the vicinity of the locus io.
The origin is the current irradiation position of the Fi welding electron beam, -tsu is the first scanning line when performing triangular scanning, 30 is the starting point of welding line detection, and the first scanning line when performing 3/ri triangular scanning. , 3 is the point for detecting the welding line 3, 33 is the end point of #tangent detection, and 3 is the scanning line of 1g3 when performing triangular scanning.

Figure 3 Structure of F'ix-axis and Y-axis scanning waveform generator
□The reference power source 36 starts operating at the rising edge of the output signal of the gate pulse generator/e.
Integrator 1 of reference power supply 3j that is reset at many points of falling.
? 7F'i is an adder for the output signal of the gate pulse generator/da and the output signal of the integrator 36.

Figure 1 is a waveform diagram showing the scanning signal of the scanning electron beam.
υ, (a) is the X-axis signal, <b) is the Y-axis signal, t is the time axis, J? The output voltage of the al'il-axis scanning waveform generator (hereinafter referred to as the X output voltage), and the output voltage of the Y-axis scanning waveform generator (hereinafter referred to as the Y-axis output voltage).

FIG. 5 shows the trajectory of the scanning electron beam, and reference 1 shows the trajectory of the scanning electron beam actually obtained (hereinafter referred to as the actual trajectory). Figure 6 shows X-axis amplifier/7 or Y-axis layer width amplifier 1
In the foot current increasing gangbang used in 5 (in the figure, it is around the X-axis), the second part is an operational amplifier with a large output, the second part is an input resistor of 3F'i, the third part is an IE current detection resistor, and the asFi feedback resistor. FIG. 7 shows the scanning signal of the scanning electron beam, (a) shows the X-axis signal, and (b) shows the Y-axis signal. Figure 5 shows the locus of the scanning electron beam.

Next, the operation will be explained. When welding the welding line 3 of the workpiece λ with the welding electron beam emitted from the electron gun, the irradiation point on the workpiece λ of the welding electron beam is set to the welding line 3.
It is necessary to make a positive 1iK match. In-process weld line detection method is used as a method for this purpose. In this detection method, the welding electron beam is deflected in time division by the deflection coils t and 9 to produce a scanning electron beam, which scans the welding electron beam in front of the current irradiation point. A scanning electron beam SF is produced as follows. The output signal of the gate pulse generator/41 causes the x-axis scanning waveform generator/j and the Y-axis scanning waveform generator 1
6 operates, and its output signal is amplified by the X-axis layer width amplifier 17 and the Y-axis amplifier 7g, respectively, and becomes t and Y@-direction coil de to deflect the scanning electron beam S along the X-axis 6 and Y-axis 7. The X-axis - Naikaro accent/TE and the Y-axis Naikaro flow Q are the X-axis detection resistors Kol and !, respectively. @It is detected by the detection resistor here and can be input to the arithmetic unit-3. On the other hand, reflected electrons or X! generated when the scanning electron beam S collides with the workpiece to be welded. / /Fi As is well known, when the irradiation point is welding or IIJ, it becomes the minimum,
It is detected by a detector 12, and an amplifier 1 is applied to the detection signal.
3, and its output signal is input to the arithmetic unit 3. It operates during the output period of the arithmetic unit 23Fi gate pulse generator/4' and calculates the difference between the time when Y@deflection inner cage EcoO becomes zero and the time when the intensity of backscattered electrons or X-rays/l becomes zero. demand. This time difference is the X-axis eccentric inward flow/? f! at the position in front of the IJ4 irradiation point of the welding electron beam bower, which is found from It's due to the error between the contact point 3 and the irradiation point. This error is output from the arithmetic unit 23 as a difference signal and is amplified by the servo amplifier. Next, the electron gun drive device! Or the welding object drive device λ group is an electron gun/-19 is the welding object-
'fr is moved in the Y-axis direction to correct the position of the irradiation point on the #I contact and electrical connection piece to be welded.

As an example of the locus 10, a triangular one is shown in FIG. In this case, weld line detection ri first scan *,? This is done in the / part. FIG. 3 shows the configuration of the X-axis and Y@O scanning shape generator for creating this triangular locus. The output signal of the gate pulse generator/l is used as the X-axis scanning waveform signal, and the Y-axis scanning waveform signal is as follows.
The voltage of the reference power supply 3j is integrated by the integrator 36 from the rising edge of the output signal of the gate pulse generator/4(), and the integrator 3j is reset by the falling edge of the output signal of the gate pulse generator/Q. to create a triangular wave9, and use it with a gate pulse generator/
This is obtained by adding the output signal of 2 with the adder 37. Therefore, the output voltage of the X-axis amplifier 17 and the Y-axis amplifier /l is the same as that of each amplifier /7. If a voltage amplification type is used for /1, each amplifier /7 shown in Figures (a) and (t)J
．． It has the same waveform as the input signals Jta and uOa of II. However, each amplifier/7. Since the load on / is due to the inductive nature of the deflection coil, as shown in Figure 7 (a+, <b)! Axis - Uchigoryu/? a and Y axis - inner basket tIL 0hF
iX-axis output voltage J9h and Y-axis output voltage 4IOa,!
:Fi will be different. Therefore, the locus will not be triangular, but will be a locus as shown by 1 in FIG. 5.

In order to make the actual trajectory d into a triangle, it is conceivable to make each of the amplifiers i't and 1tt a constant current type as shown in FIG. In this case, the negative plane current is determined by the current detection resistor 4I4
Detected by I and multiplied by negative NIN to obtain the same output current as the input voltage signal. However, since welding is interrupted during the welding inspection period, the time allowed for detection is ilt/~10mm, and since a rectangular wave signal is used, each increaser /'/, / is required to have a very wide frequency band. Therefore, transient oscillations in the output current due to instability of each amplifier/7゜it are unavoidable.
, waveform itb as shown in (b).

Becomes a Ob. Therefore, as shown in FIG. 3, the trajectory oscillates near the detection starting point 30 and becomes like ``da/a'', and oscillates near the origin 21 and becomes like ``pass''.

Since the conventional electron beam welding machine that performs in-process welding detection is configured as described above, when a voltage amplification type deflection signal amplifier is used, the transient response of the -direction coil current is reduced by the time constant of the deflection coil circuit. The deflection speed of the electron beam becomes slow. Therefore, when welding line detection is performed using time-division welding beam current during welding, the time required for welding line detection becomes longer, which adversely affects the molten part of the welded part. The heat input to the welding scanning portion increases, causing melting and thermal distortion of the non-welded portion. (9) When a constant current type deflection signal amplifier is used, the deflection current oscillates transiently, the trajectory of the scanning electron beam on the workpiece is distorted, and signal processing after welding line detection is complicated and takes a long time. Such shortcomings were rare.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and it uses a pulse voltage that instantly moves the electron beam irradiation position on the object to be welded, and a trajectory of the scanning electron beam on the object to be welded. The overall object is to provide an electron beam deflection system wItt- capable of directing an electron beam at high speed by applying a voltage waveform t- corresponding to t- to the deflection coil during PU or sequentially.

Hereinafter, first, the principle of this invention will be explained with reference to the drawings. In factor (a), Shiro is the deflection signal generator, Schif is the deflection coil with self-inductance L-ij-, Ift is the output resistance of the deflection signal generator and the deflection coil reference 70.
Series resistance, il', with a resistance value R that equivalently represents the internal resistance
i The deflection that flows through this circuit flows out.

In order to flow the current io shown in Fig. 9 (b') through the deflection coil differential, it is sufficient to generate a step voltage of E = Ri shown by the negative direction signal generator 1Ibne type SO. , the 314-pass response of electric power fii is expressed by the following equation, as shown in the waveform j/ of Figure D (b).

However, T = 4, and the constant of the same south of the circuit. Therefore,
The normalized time t/r approaching the value of io is 1° deO
s = t/r = λ, 301° De De whisper: Customer; Da, 1/1, of! De, De: Customer -6, De
It becomes l.

next,! The open signal generator 6 generates a larger step voltage -S, and at the time 1 when the current 1 differs by 1 degree. niE
Let us consider a method of lowering it to l't-E. in this case,'
The transient response of flow 1 is expressed by the following equation, as shown in waveform S3 of Figure D (C).

i=”i (t-e-T) O≦t≦1゜E.

1x-t, (t Moreover, to/r can be expressed by the following formula.

r=-...(-town E.

Therefore, the relationship between 8041 and j67 is E, =yoE
*: t/r=θ, 101H, -10010,/,
-0,010/. For example, by the former method, 1o
For the time it takes to reach the value of 99 whispers, the latter's 1=10
The method of adding the E0 pulse only takes about a few minutes, and there is no difference from the final setting value of 1.

Next, consider the case where a Lang electric current fi 1=Kt is applied to the deflection coiler 7. In this case, when the negative direction signal generator 6 generates a lamp voltage j da -KRt t-, the transient response of the current 1 becomes as shown in the waveform s3 of Fig. 10 (a), and is expressed by the following equation.

1wKr(θ-+-/)+Kt Therefore, a deviation of τ(eτ-/) occurs with respect to the set value. Then, in the −open signal generator llb, JC=KRt K
When a waveform j6 with a step voltage of E2-Kr superimposed is generated, the transient response of current 1 is #! /θ Waveform j in diagram (b)
'7, and is expressed by the following equation.

1=Kt Therefore, no deviation from the set value occurs.

Next, an embodiment based on the above-mentioned principle will be described with reference to the drawings. In FIG. 11, st*, sgb, ri gc and jjd ri, pulse voltage that moves the irradiation position vt at 1lii1 (hereinafter referred to as moving pulse voltage), jta and tyb voltage waveforms corresponding to the F'i locus (hereinafter referred to as moving pulse voltage), , the reference voltage waveform i). Also, in Figure 1,
A oFix axis D/A linear 7 /(-/, 4/$1
! In the Y/S D/A converter, number 6 is a gate signal corresponding to the output signal of a conventional gate pulse generator, and number 3 is generated by a microcomputer.

Next, the operation will be explained.

The locus of the triangular waveform of the M-diagram is shown on the workpiece to be welded f, J/.

Consider a case in which a weld line 3 is detected by scanning an electron beam along three lines. The scanning from the origin 2j to the detection start point 30 and the scanning from the detection end point 33 to the origin 2t are performed instantaneously, regardless of the welding line detection.

Scanning from detection start point 3θ to detection end point 33 ViY@7
parallel to and at a constant speed. In this case, the waveform required for the X-axis deflection current is /PC in FIG. 11(a), and the voltage waveform required to flow this current iqc is jta, ! according to the above principle. ;9a, jib. In addition, the required waveform for the Y-axis deflection current is 200 and 69 in Figure 1 (b), and the voltage waveform required to flow this current 200 K is based on the above principle , szad.

These voltage waveforms can be divided into several basic waveforms. Move pulse voltage 3 &, jlc is irradiation position #
It moves it from the origin -t to the detection start point 30, and it moves the moving pulse voltage Hb and the sgdFi irradiation position from the detection end point 3J to the origin t. The peak voltages of the moving pulse voltages rttt, rib, zxc, and sxd are set to voltages close to the maximum voltages that can be output by the rix-axis amplifier 77m and the Y-axis layer -a/Ka. In addition, during the reference voltage waveform 1m Fi welding error detection period,
The reference voltage waveform tyb is designed to move the irradiation position parallel to the Y-axis at a constant speed during the welding line detection period, and as shown in the above principle, the step voltage is applied to the lamp voltage. -C. The synthetic voltage waveform of these moving pulse voltages and reference voltage waveforms can be easily created using a pulse circuit, but these voltage waveforms can also be created using a combination of pulse voltage and lamp voltage. As shown in Figure 1, a microcomputer
13 and X-axis and Y-axis 1)/A converter to.

61, voltage waveforms can be synthesized quickly and easily.

Although the above embodiment describes an electron beam welding machine that detects in-process welding lines, it is also possible to use an electron beam hardening machine that moves the electron beam irradiation position at high speed and with high precision. It has a similar effect. In the case of an electron beam hardening machine, scanning is performed at high speed and intermittently in order to limit the heat input range of electron beam power.

As described above, according to the present invention, the pulse voltage that instantaneously moves the electron beam irradiation position t on the workpiece and the voltage waveform corresponding to the trajectory of the scanning electron beam on the workpiece can be simultaneously generated. is configured to be applied to the deflection coils sequentially, so compared to the case where no moving pulse voltage is applied, the
It can perform 700 times faster scanning, does not cause transient vibrations after movement, and has the advantage of being able to scan at a high position f# degree even during movement.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing an electron beam welding machine that performs in-process welding line detection, Figure 2 is a diagram showing the locus of the scanning electron beam irradiation position on the workpiece, and Figure 3 is a diagram showing the conventional scanning waveform. The configuration diagrams of the generator, Figures 7 to 7, are diagrams for explaining the conventional drawbacks, Figures WJ9 (al, (bJ
, (CJ and alO diagrams (a), (bl is a detailed explanation of this invention), Figure 11 (a and (
bJ is a diagram for explaining the entire operation according to an embodiment of the present invention, and the first diagram is a schematic configuration diagram showing a scanning waveform generator according to a practical example of the present invention. In the figure, l is an electron gun,
2 is the object to be welded, l is the one-wheel direction coil, ? Fiy@-direction coil, no coil output, 13 is amplifier, /? is X@deflection inner basket t, λO is Y axis-inner basket ft*5irix@detection resistor,
2.11dY-axis detection resistor. 23 is an arithmetic unit, 211ri servo amplifier, 2 is an electron gun drive device, and welded object driver wJvctILe 3
za and stb are the X-axis movement pulse voltages, zrc and jtd are the Y-axis movement pulse voltages, 6θViX @
11/M converter e A/Fi Y axis D/re converter, 1 unit is controlled by a microcomputer. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent: Katsura W Detective - Ryo 1 Figure 44 Figure 2 Inma Figure 3 Horse Figure 6 Island 7 Figure Figure Ul 8 Figure Gu 4 Figure Island 5 Figure Horse 9 Figure Horse 10 Figure

Claims (1)

[Claims] +1) In an electron beam processing device, a deflection coil to which a deflection current is supplied for deflecting the electron beam so that the electron beam draws a predetermined scanning trajectory; and a deflection coil corresponding to the predetermined scanning trajectory. means for simultaneously or sequentially superimposing a voltage pulse on the scanning trajectory voltage waveform for correcting a waveform difference between the scanning trajectory voltage waveform and the scanning trajectory voltage waveform due to the previous RFI direction current passing response; An electron beam deflection device comprising: (2) The electron beam processing device according to claim 1, wherein the electron beam processing device is an electron beam welding machine, and the deflection coil and the means are provided for time-divisionally detecting the curve tangent during welding. Beam deflection device.