JPS6134905B2 - - 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(E1 I1)/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 are easy. Already 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 measuring 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 along a welding line 1a of the workpiece 1 is supplied between the workpiece 1 and the welding electrode 2. This is a welding heat input measurement device that detects electric power and measures it from a welding power signal P corresponding to the welding electric power. In particular, in the present invention, arc 3
A welding length setting device 9 that sets a welding length signal L corresponding to the moving distance of A power detection circuit 11 that outputs a power detection signal P/L divided by the welding length signal L, and a converter 6 that outputs a pulse signal F/L of a frequency corresponding to the power detection signal P/L.
, an integration circuit 7 that integrates the pulse signal F/L during the arc movement period and outputs an integral signal ∫F/Ldt, and a reset circuit 8 that resets the integration circuit 7.
and a display 9 for displaying the integral value of the integral signal 7.
It is characterized by having the following.

[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], the average welding heat input Q [K
ilo-joule/cm] is a constant K4, ∫ ^T _p
Vdt＝
Since it is L, It can be expressed as. The present invention is an apparatus for measuring welding heat input based on the above equation (4).

[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/ which is obtained by dividing a current signal I corresponding to a welding current obtained from a current transformer 5a and a voltage signal E corresponding to an arc voltage by a signal L set by a welding length setting device 10, which will be described later.
This is a power calculator that takes as input L and outputs 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 the signal L. . Further, 6 is a converter, for example, a voltage/frequency converter, which outputs a pulse signal F/L of a frequency corresponding to the output signal P/L of the power calculator 5. 7 integrates the pulse signal F/L output from the converter 6 during the movement period of the arc to obtain ∫F/
An integrating circuit outputs an integral signal Ldt; 8 is a reset circuit that resets the integrating operation of the integrating circuit 7;
Reference numeral 9 denotes a display that displays the value of the integrated signal from the integrating circuit 7. Reference numeral 10 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. Reference numeral 11 denotes a power detection circuit that includes a welding length setting device 10 and a power calculator 5, and outputs a power detection signal P/L.

To explain the operation of the above embodiment, the reset circuit 8 includes, for example, a push button switch;
Before starting welding, the integral circuit is reset by pressing this push button switch. When the welding machine is driven to generate an arc and the arc 3 is moved along the welding line 1a, a current signal I corresponding to the welding current I1 and a voltage signal E corresponding to the arc voltage E1 are sent to the welding length setting device 10. The signals E/L divided by the welding length signal L are input to the power calculator 5, and the power detection signal P/L corresponding to the welding power is output from the power calculator 5 to the converter 6. The converter 6 outputs a pulse signal F/L with a frequency approximately proportional to the magnitude (for example, voltage value) of the power detection signal P/L, and when the pulse signal F/L is input to the integrating circuit 7, the integrating circuit 7 starts the integration operation, and the integration is continued 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 7 stops the integrating operation and holds the integrated value at that time. Here, if T is the time the arc has moved, the integral value of the integral signal output by the integrating circuit 7 is ∫F/
Ldt, and the display 9 indicates this integral value.

Next, the setting method and operation of the welding length setting device 10 for setting the welding length signal L corresponding to the moving distance of the arc (i.e., the welding length) and the operation during use will be described. Now, the total heat input at the moving distance of the arc = 1 [cm] is 100
Suppose that it is [kilo-joule]. Further, the welding length setting device 10 may be, for example, a variable resistor as shown in the figure.
Assume that the indicator 9 is a meter using the principle of a voltmeter. In this case, welding length setting device 10
When the slider 10a of the variable resistor constituting the variable resistor is set at the position A (rightmost position) shown in the resistor, the indication of the meter constituting the display 9 is 100 [kilo-joule/ Set up a scale so that it reads 100 [kilo-joule/cm], and also set up 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 10 is calibrated from right to left to indicate the moving distance of the arc, that is, the welding length, 1 to 10 [cm]. These scales are provided according to the linearity or nonlinearity characteristics of the circuit.

When the welding length Lo=1 [cm], the integrated value of electric power becomes 100 [kilo-joule], which is considered to be the maximum heat input in normal welding. Therefore,
As above, set the full scale to 100 [kilo-joule/
cm], in normal measurements, the meter as the indicator 9 will not go overscale due to the output corresponding to the integrated value of electric power per unit length of welding length.

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 10a 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, that is, the signal corresponds to 80 [kilo-joule/cm]. The converter 6 receives the output signal P/L of the power calculator 5.
A pulse signal F/L of a frequency corresponding to is output. The integrating circuit 7 integrates the pulse signal F/L output from the converter 6, and the display 9 displays a signal corresponding to the output signal ∫F/Ldt of the integrating circuit 7, that is, 80 [kilo-joule/cm] Display. Further, when the welding length L=10 [cm], the position of the sliding terminal 10a of the variable resistor is set at a position C corresponding to approximately 1/10 of the position A described above. At this time, if the integrated value of power is, for example, 900 [kilo-joule], the output of the power calculator 5, that is, the power detection circuit 1
The output of 1 is P/L=900/10, that is, 90 [kilo-joul
e/cm].

In this embodiment, as an input to the integrating circuit 7, 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 pulse signal F/L corresponding to the detected power detection signal P/L is used, the capacitance of the converter 6 and the integrating circuit 7 can be reduced. That is, if the pulse signal F/L corresponding to the power detection signal P/L obtained by dividing the welding power signal P by the signal L is input to the integrating circuit 7, the longer the welding length, the more the pulse signal F/L is input to the integrating circuit 7. Since the signal becomes smaller, there is no need to increase the capacity of the integrating circuit 7 even when the welding length is increased. In other words, even if the welding length becomes longer, the amount integrated by the integrating circuit 7 remains approximately constant. Further, according to the embodiment, since the capacity of the integrating circuit 7 can be reduced, a portion of the integrating circuit with good linearity can be used for the integrating operation, and errors can be minimized.

Further, according to each of the above embodiments, the power detection circuit 11
Also, the installation location of the converter 6 and the installation location of the circuits after the integrating circuit 7 are far apart, and the output signal line of the power detection circuit 11 is caused by induction caused by extremely large welding current flowing in the surrounding welding current carrying circuit. This is particularly advantageous in voltage-sensitive applications. That is, in the apparatus of this embodiment, the power detection signal P/L corresponding to the welding power detected by the power detection circuit 11 is transmitted by the converter 6 provided close to the power detection circuit 11.
The integrating circuit 7 converts the power into a pulse signal F/L with a frequency corresponding to the corresponding signal and sends the signal to the pulse signal F/L.
Therefore, even if an induced voltage is applied due to the application of welding current, the induced voltage and the pulse signal can be easily separated, and the welding heat input can be accurately measured. Furthermore, since the entire device can be processed using analog signals, it has the advantage of being easier and cheaper to manufacture than a device having a counter that counts digital signals.

In the above embodiment, the welding length setting device 10
is inserted into the arc voltage detection circuit, but it may also be inserted into 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=
It becomes P/L.

Further, in the above embodiment, a push button switch is used as the reset circuit 8, but the reset circuit 8 operates by inputting the output signal of the timer or the signal output from the power calculator 5 at the start of the next welding, and performs the integration. Of course, a reset circuit for resetting the circuit 7 may also be used.

FIG. 2 is a configuration diagram showing another embodiment of the present invention, in which the weld length setting device 10 is composed of a fixed low hole device equipped with a plurality of pull-out taps and a changeover switch. A setting device 10 is provided on the output side of the power calculator 5, and a power detection circuit 11 is configured. The setting operation of the welding length setting device 10 is as follows:
Compared to the case of the variable resistor shown in FIG. 1, there is no essential difference except that it is stepped. As in the embodiment shown in FIG. 2, a welding length setting device 10 is provided on the output side of the power calculator 5, and the welding power signal P corresponding to the welding power is obtained by the power calculator 5. is divided by L set by the welding length setting device 10, and the power detection circuit 11 outputs the power detection signal P/
Even if L is obtained, the capacitance of the converter 6 and the integrating circuit 7 can be reduced as in the embodiment shown in FIG.

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 11 to generate the power detection signal P/L.
However, the configuration of this power detection circuit 11 can be modified as appropriate. For example, when performing manual welding using a welding power source with constant current characteristics,
Since the current signal I 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. vice versa,
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 corresponds to the welding current. The current signal I corresponds 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. And if the voltage signal E corresponding to the arc voltage is not constant,
By combining these signals with a signal corresponding to the arc voltage or a signal corresponding to the output signal of the arc voltage setting device, a welding power signal P corresponding to the instantaneous power value can be obtained.

As the display device 9 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 the pulse signal F/L corresponding to /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.

Furthermore, according to the device of the present invention, the installation location of the power detection circuit and converter is far from the installation location of the circuit after the integrating circuit, and the induced voltage is generated when an extremely large welding current flows through the surrounding welding current energization circuit. However, even if it is added to the output signal line of the power detection circuit, the power detection signal P/L is converted into a pulse signal F/L by a converter and sent to the integrating circuit, making it easy to separate the induced voltage and the pulse signal. The welding heat input can be measured accurately. Furthermore, since the entire device can be processed using analog signals, it has the advantage of being easier and cheaper to manufacture than a device having a counter that counts digital signals.

[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... Work to be welded, 1a... Welding line, 2... Welding electrode, 3... Arc, 4... Welding power source, 5... Power calculator, 6... Converter, 7... Integrating circuit, 8 …
...Reset circuit, 9...Display device, 10...Welding length setting device, 11...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 a pulse signal F/L; a converter that outputs a pulse signal F/L having a frequency corresponding to the power detection signal P/L; /
A welding heat input measuring device comprising: an integrating circuit that outputs an integral signal called Ldt; a reset circuit that resets the integrating circuit; and a display that displays an integral value of the 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.