JPS6134902B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a welding heat input measuring device for measuring welding heat input when a welding holder or welding torch is moved manually or semi-automatically. It is.

[Prior Art] It has been known that the amount of welding heat input to a welded part is an important factor that influences the welding result.
Generally, arc voltage is E1 (volt) and welding current is I1
(A), welding speed is V1 (cm/sec), electrical input to the workpiece is P1 (kw), heat input per unit length is Q
(Kilo-Joule/cm), and if the constant is K1, then Q=K1(P1/V1)=K1(E1I1)/V1...(1) holds true. This equation (1) can be expressed even more simply in some cases.

For example, when manual welding is performed using a welding power source with constant current characteristics, the welding current I1 (A) has a substantially constant value, so if it is a constant K2, then Q = K2 (E1 / V1) ... (2) holds true.

Also, when performing semi-automatic welding using a welding power source with constant voltage characteristics, the arc voltage E1 (volt) is approximately constant, so if the constant is K3, Q = K3 (I1 / V1) ... ( 3) holds true.

In the conventional automatic arc welding method, the signal V corresponding to the welding speed V1 can be easily obtained by detecting the traveling speed of the automatic traveling trolley, so heat input measurement in the automatic welding machine and control based on the measured value have already been performed. Proposed.

[Problems with Prior Art] However, in manual welding and semi-automatic welding, there is no automatic traveling cart and the welding torch is artificially moved along the welding line, making it impossible to detect the welding speed V1. Therefore, in the past, it has been extremely difficult to obtain a device that can simply, quickly and accurately measure heat input in manual or semi-automatic welding.

In view of the above, an object of the present invention is to provide a welding heat input measurement device for determining the average welding heat input over a distance traveled by the arc during a given period in arc welding such as manual welding and semi-automatic welding.

[Means for Solving the Problems] In order to solve the above problems, the present invention, as shown in FIGS. 1 and 2 showing an embodiment, Welding heat input of an arc welding device that performs welding while moving an arc 3 generated from a welding electrode 2 is detected by detecting the welding power supplied between the workpiece 1 and the welding electrode 2 and corresponding to the welding power. This is a welding heat input measurement device that measures from a welding power signal P. In particular, the present invention includes a welding length setting device 9 that sets a welding length signal L corresponding to the moving distance of the arc 3, and a power calculator 5 that outputs a power signal corresponding to the input power from the input voltage and input current. A power detection circuit 10 outputs a power detection signal P/L obtained by dividing a welding power signal P by a welding length signal L, and integrates the power detection signal P/L during the movement period of the arc to obtain ∫P/Ldt. It is characterized by comprising an integrating circuit 6 for outputting a signal, a reset circuit for resetting the integrating circuit 6, and a display 8 for displaying the integrated value of the integrated signal.

[Operation of the invention] The present invention is capable of measuring the distance L traveled by an arc during a given period in manual welding or semi-automatic welding.
If the time required to weld [cm] is T [sec], then the average welding heat input Q within that distance is
[kilo-Joule/cm] is a constant K4, ∫ ^T ₀ Vdt
= L, so It can be expressed as. The present invention is an apparatus for measuring welding heat input based on equation (4) above.

[Example] An example of the welding heat input measuring device of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a workpiece, 1a is a welding line, 2 is a welding electrode that moves along the welding line 1a while generating an arc 3, and 4 5 is a welding power source, and 5 is a signal E/L obtained by dividing a current signal for the welding current obtained from the current transformer 5a and a voltage signal E corresponding to the arc voltage by a signal L set by a welding length setting device 9, which will be described later. This is a power calculator that outputs as an input a power detection signal P/L obtained by dividing a welding power signal P corresponding to the welding power supplied between the workpiece 1 and the welding electrode 2 by a signal L. 6 is an integrating circuit that integrates the power detection signal P/L output from the power calculator 5 during the moving period of the arc and outputs an integral signal ∫P/Ldt; 7 is a reset circuit that resets the integration operation of the integrating circuit 6. The circuit 8 is a display that displays the value of the integrated signal of the integrating circuit 6. Reference numeral 9 denotes a welding length setting device for setting a welding length signal L corresponding to the moving distance of the arc. In this embodiment, it is inserted into a circuit for detecting the welding voltage to set the voltage E corresponding to the moving distance of the arc. Generates a signal E/L divided by L. 10 is composed of a welding length setting device 9 and a power calculator 5,
This is a power detection circuit that outputs a power detection signal P/L.

To explain the operation of the above embodiment,
The reset circuit 7 is, for example, a push button switch 7a.
This push button switch 7 is pressed before starting welding.
Reset the integration circuit by pressing a. Drive the welding machine to generate an arc, arc 3
moving along the welding line 1a, the welding current I1
The current signal I corresponding to the arc voltage E1 and the voltage signal E corresponding to the arc voltage E1 are the welding length signal L of the welding length setting device
The signal E/L divided by
L (for example, a voltage signal) is output from the power calculator 5 to the integrating circuit 6. When the power detection signal P/L is input to the integration circuit 6, the integration circuit 6 starts an integration operation, and the integration continues while welding is being performed.

When welding is completed, the current signal I corresponding to the welding current input to the power calculator 5 becomes zero. Therefore, the power detection signal P/
The value of L (IE)/L also becomes zero, and the integrating circuit 6 stops the integrating operation and holds the integrated value at that time.
Here, if the time the arc moves is T, the integral value of the integral signal output by the integrating circuit 6 is ∫ ^T ₀ P/Ldt
The display 8 indicates this integral value. Nao L
is the specified value, so the display 8 shows ∫ ^T ₀
It is the same as Pdt/L, and it can be seen that the same result as the above equation (4) can be obtained.

Next, the setting method and operation of the welding length setting device 9 for setting the welding length signal L corresponding to the moving distance of the arc (i.e., the welding length) and its operation will be described. The total heat input at the current moving distance of the arc, Lo = 1 [cm], is 100
Suppose that it is [Kilo−Joule]. It is also assumed that the welding length setting device 9 is, for example, a variable resistor as shown in the figure, and the indicator 8 is a meter using the principle of a voltmeter. In this case, when the slider 9a of the variable resistor constituting the welding length setting device 9 is set to the illustrated position A (the rightmost position) of the resistor, the indication of the meter constituting the display 8 is full. on scale
Set up a scale to read 100 [Kilo-Joule/cm], and also set a scale to display other heat inputs below 100 [Kilo-Joule/cm]. On the other hand, the variable resistor constituting the welding length setting device 9 is calibrated to indicate the moving distance of the arc, that is, the welding length, from 1 to 10 [cm]. These scales are provided according to the linearity or nonlinearity characteristics of the circuit.

When the integrated value of electric power reaches 100 [Kilo-Joule] when the welding length is Lo-1 [cm], it is considered to be the maximum heat input in normal welding. Therefore, as shown above, the full scale is set to 100 [Kilo-Jou
le/cm], the meter serving as the indicator 8 will not be overscaled by the output corresponding to the integrated value of electric power per unit length of welding length in the case of normal measurement.

Now, assuming that the circuit characteristics have linearity,
When the welding length L=5 [cm] in the actual measurement, the position of the sliding terminal 9a of the variable resistor is set at position B, which corresponds to approximately 1/5 of the position A described above. At this time, the integrated value of the electric power supplied to the workpiece 1 and the welding electrode 2 is, for example, 400 [Kilo-
Joule], the power detection signal P/L output by the power calculator 5 is (E/L)I=400/
5, so the meter on the display is 80 [Kilo-Joul
e/cm]. In addition, in the case of welding length L = 10 [cm], the position of the sliding terminal 9a of the variable resistor is set to position C, which corresponds to approximately 1/10 of the position A described above.
Set to . At this time, the integrated value of electric power is, for example,
900 [Kilo-Joule], the output of the power calculator 5, that is, the output of the power detection circuit 10, is P/L.
= 900/10, so the meter on display 8 is 90 [Kil
o-Joule/cm] will be displayed.

In this embodiment, as an input to the integrating circuit 6, the welding power signal P corresponding to the welding power supplied between the workpiece 1 and the welding electrode 2 is divided by the signal L corresponding to the welding length. Since the calculated power detection signal P/L is used, the capacity of the integrating circuit 6 can be reduced. That is, if the power detection signal P/L obtained by dividing the welding power signal P by the signal L is input to the integrating circuit 6, the longer the welding length, the smaller the signal input to the integrating circuit 6. Even if the length is increased, there is no need to increase the capacity of the integrating circuit 6. In other words, even when the welding length becomes longer, the amount integrated by the integrating circuit 6 remains approximately constant. Further, according to this embodiment, the integrating circuit 6
Since the capacitance of can be made small, a portion of the integrating circuit with good linearity can be used for the integrating operation, and errors can be minimized.

In the above embodiment, the welding length setting device 9 is
Although it is inserted in the arc voltage detection circuit, it may also be inserted in the welding current detection circuit to divide the current signal I by the signal L. Even in this case, the signal output from the power calculator 5 is (EI)/L=P/
It becomes L.

Further, in the above embodiment, a push button switch is used as the reset circuit 7, but the reset circuit 7 is operated by inputting the output signal of the timer or the signal output from the power calculator 5 at the start of the next welding. Of course, a reset circuit for resetting the integrating circuit 6 may also be used.

FIG. 2 is a configuration diagram showing another embodiment of the present invention, in which a welding length setting device 9 is composed of a fixed resistor equipped with a plurality of pull-out taps and a changeover switch, and this welding length setting device A power detector 9 is provided at the output end of the power calculator 5, and a power detection circuit 10 is configured. The setting operation of the welding length setting device 9 is essentially the same as that of the variable resistor shown in FIG. 1, except that it is performed stepwise. As in the embodiment shown in FIG. 2, a welding length setting device 9 is provided on the output side of the power calculator 5, and the power calculator 5 obtains a welding power signal P corresponding to the welding power. Even if the power detection signal P/L is obtained from the power detection circuit 10 by dividing by L set by the welding length setting device 9, the integration circuit 6
capacity can be reduced.

In each of the embodiments shown in FIGS. 1 and 2 above,
The current signal I corresponding to the welding current value obtained from the current transformer 5a and the voltage signal E corresponding to the arc voltage value are input to the power detection circuit 10 to generate the power detection signal P/L.
However, the configuration of this power detection circuit 10 can be modified as appropriate. For example, when performing manual welding using a welding power source with constant current characteristics,
Since the current signal corresponding to the welding current value is substantially constant, the voltage signal E corresponding to the arc voltage becomes the welding power signal P corresponding to the instantaneous power value. Further, if a welding current setting device is present in the welding power source 4, a signal corresponding to the output signal of this setting device may be used as the current signal I corresponding to the welding current. Conversely, when performing semi-automatic welding using a welding power source with constant voltage characteristics, the voltage signal E corresponding to the arc voltage value is approximately constant, so the welding power signal P corresponding to the instantaneous power value is A current signal I corresponds to the current corresponding to the current.

Further, if the welding power source 4 includes an arc voltage setting device, a signal corresponding to the output signal of this setting device may be used as the voltage signal E corresponding to the arc voltage.

Furthermore, the current signal I corresponding to the welding current can be obtained by detecting leakage magnetic flux in the vicinity of the welding current-carrying circuit with a coil and using its output signal, or by detecting the Joule heat generated in the welding circuit with a thermocouple. The output signal can be used. If the voltage signal E corresponding to the arc voltage is not constant, the instantaneous power value can be determined by combining these signals with the signal corresponding to the arc voltage or the signal corresponding to the output signal of the arc voltage setting device. A welding power signal P can be obtained.

As the display device 8 shown in FIGS. 1 and 2,
In addition to a meter using the principle of a voltmeter, a digital display having an A/D converter, a printer, etc. can be used.

It goes without saying that the present invention can be applied to heat input measurement in automatic welding as well as manual or semi-automatic welding.

[Effects of the Invention] As described above, according to the present invention, it is possible to quickly and easily measure welding heat input in manual or semi-automatic welding, etc., which has conventionally been difficult to measure. In particular, according to the present invention, a power detection signal P obtained by dividing a welding power signal P corresponding to the welding power supplied between the workpiece and the welding electrode by a signal L corresponding to the welding length is used as an input to the integrating circuit. Since /L is used, the capacity of the integrating circuit can be reduced. Further, according to the present invention, since the capacity of the integrating circuit can be reduced, a portion of the integrating circuit with good linearity can be used for the integrating operation, and there is an advantage that measurement errors can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the welding heat input measuring device of the present invention, and FIG. 2 is a block diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Workpiece, 1a...Welding line, 2...Welding electrode, 3...Arc, 4...Welding power source, 5...Power calculator, 6...Integrator circuit, 7...Reset circuit, 8 ...Display device, 9...Welding length setting device, 10...
...Power detection circuit.

Claims (1)

[Scope of Claims] 1. Welding heat input of an arc welding device that performs welding while moving an arc generated from a welding electrode along a welding line of the workpiece is supplied between the workpiece and the welding electrode. In a welding heat input measuring device that detects a welding power generated by the welding power and measures it from a welding power signal P corresponding to the welding power, the welding length signal L corresponding to the moving distance of the arc is provided.
and a power calculator that outputs a power signal corresponding to the input power from input voltage and input current.
power detection signal P/ divided by the welding length signal L
a power detection circuit that outputs the power detection signal P/L; an integration circuit that integrates the power detection signal P/L during the moving period of the arc and outputs an integral signal ∫P/Ldt; a reset circuit that resets the integration circuit; A welding heat input measuring device comprising: a display device that displays an integral value of an integral signal. 2 The power detection circuit divides a current signal or a voltage signal corresponding to the current and voltage supplied between the workpiece and the welding electrode by the welding length signal L, and the power calculator calculates the power Detection signal P/
The welding heat input measuring device according to claim 1, wherein the welding heat input measuring device outputs L. 3. The power detection circuit obtains the welding power signal P by inputting a current signal and a voltage signal corresponding to the current and voltage supplied between the workpiece and the welding electrode to the power calculator, The welding heat input measuring device according to claim 1, wherein the welding power signal P is divided by the welding length signal L of the welding length setting device.