JP2004237342A - Pulse output control method, and consumable electrode type pulse arc welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a consumable electrode type pulse arc welding equipment to suppress spatter when arc is unstable. <P>SOLUTION: The consumable electrode type pulse arc welding equipment comprises a welding voltage detection unit 7 to detect the welding voltage, a welding voltage setting unit 9 to set the welding voltage, an error amplification unit 8 which receives the output of the welding voltage detection unit 7 and the output of the welding voltage setting unit 9, and amplifies the difference between the two inputs, a base current setting unit 12 to set the base current, a peak current setting unit 15 to set the peak current, a base current calculation unit 14 which receives the output of the base current setting unit 12 and the output of the error amplification unit 8 and increases/decreases the base current according to the output of the error amplification unit 8, and a peak current operation unit 16 which receives the output of the peak current setting unit 15 and the output of the error amplification unit 8, and increases/decreases the peak current according to the output of the error amplification unit 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a consumable electrode (hereinafter, referred to as a wire) is fed, and a peak current and a base current are alternately and repeatedly supplied between the wire and a welding base material (hereinafter, referred to as a base material) to control welding output. The present invention relates to a welding output control method and a consumable electrode type pulse arc welding apparatus.
[0002]
[Prior art]
In recent years, the demand for low spatter of welding has been further increased in order to improve productivity. In particular, it is required to reduce spatter at the time of arc start and when the protrusion length changes due to a positional shift of a work or the like.
[0003]
The conventional consumable electrode type pulse arc welding machine shortens the pulse period so as not to change the average of the pulse frequency and lowers the welding voltage when increasing the welding speed, and generates a short circuit regularly for each pulse. This suppresses the amount of spatter generated. (For example, see Patent Document 1)
FIG. 3 shows the above-mentioned conventional consumable electrode type pulse arc welding machine, wherein 1 is an input power source, 2 is a first rectifier, 3 is an inverter circuit, 4 is a main transformer, 5 is a second rectifier, 6 Is a reactor, 7 is a welding voltage detecting unit, 8 is an error amplifying unit, 9 is a welding voltage setting unit, 10 is a pulse output setting unit, 11 is a pulse frequency setting unit, 13 is a wire feeder, 22 is a torch, and 23 is The wire 24 is a base material.
[0004]
The operation of the consumable electrode type pulse arc welder configured as described above will be described.
[0005]
When the welding voltage is lowered (performed when the welding speed is increased, etc.), the pulse period is set so that the average of the pulse frequency is not changed. Generates and suppresses the amount of spatter.
[0006]
[Patent Document 1]
Japanese Patent No. 3075263
[Problems to be solved by the invention]
However, the conventional consumable electrode type pulse arc welding machine can suppress spatter during high-speed welding, etc., but the arc is unstable when the protruding length changes, such as when starting the arc or when the position of the work shifts. In other words, when the fluctuation of the welding output voltage is large, the pulse frequency must be increased in order to correct the large fluctuation, and it is necessary to greatly change the pulse frequency when the wire feed rate is constant. There is a problem that the amount of spatter is large because irregular short-circuit occurrence increases and the amount of spatter generation increases without a pulse 1 drop being established.
[0008]
An object of the present invention is to provide a consumable electrode type pulse arc welder which suppresses the above-mentioned spatter when the arc is unstable.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a pulse output control method according to a first aspect of the present invention is to provide a pulse output control method in which a peak current and a base current are repeatedly supplied in a pulsed manner between a welding wire and a welding base material, and the peak current and the base current are reduced from a condition that does not cause short circuit The pulse period is set so that the average of the pulse frequency of the current is kept constant by using the set welding voltage or the signal corresponding to the set welding voltage and the welding output voltage or the signal corresponding to the welding output voltage when set as such. And, when the welding output voltage or the signal corresponding to the welding output voltage is lower than the set welding voltage or the signal corresponding to the set welding voltage, increasing at least one of the base current or the peak current. It is.
[0010]
When the arc becomes unstable by this control method, that is, when the fluctuation of the welding output voltage is large, the fluctuation of the pulse frequency is suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation. Accordingly, irregular short circuiting can be suppressed and spatter can be suppressed.
[0011]
A pulse output control method according to a second aspect of the present invention provides a set welding voltage or a set welding voltage when a peak current and a base current are repeatedly supplied in a pulsed manner between a welding wire and a welding base metal and reduced from a condition in which a short circuit does not occur. And the pulse period is set so as to keep the average of the pulse frequency of the current constant by using the welding output voltage or the signal corresponding to the welding output voltage in the case where the welding output voltage is set as described above. When the voltage or the signal corresponding to the welding output voltage is higher than the set welding voltage or the signal corresponding to the set welding voltage, at least one of the base current and the peak current is reduced.
[0012]
When the arc becomes unstable by this control method, that is, when the fluctuation of the welding output voltage is large, the fluctuation of the pulse frequency is suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation. Accordingly, irregular short circuiting can be suppressed and spatter can be suppressed.
[0013]
The pulse output control method according to a third invention is the pulse output control method according to the second invention, wherein the welding output voltage or a signal corresponding to the welding output voltage is lower than a set welding voltage or a signal corresponding to the set welding voltage. At least one of the base current and the peak current is increased.
[0014]
When the arc becomes unstable by this control method, that is, when the fluctuation of the welding output voltage is large, the fluctuation of the pulse frequency is suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation. Accordingly, irregular short circuiting can be suppressed and spatter can be suppressed.
[0015]
In a pulse output control method according to a fourth aspect, an upper limit and a lower limit are set to the base current and the peak current according to at least one of a wire diameter and a wire material.
[0016]
Next, a consumable electrode type pulse arc welding apparatus according to a fifth aspect of the present invention includes a welding voltage detection unit for detecting a welding voltage, a welding voltage setting unit for setting a welding voltage, an output of the welding voltage detection unit, and the welding voltage. An error amplifying unit that receives an output of the setting unit as an input and amplifies a difference between the two inputs, a base current setting unit that sets a base current, a peak current setting unit that sets a peak current, and an output of the base current setting unit. A base current calculation unit that receives the output of the error amplification unit as an input and increases or decreases a base current in accordance with the output of the error amplification unit; an output of the error amplification unit that receives an output of the peak current setting unit and an output of the error amplification unit as an input And a peak current calculation unit that increases and decreases the peak current according to. As a result, when the fluctuation of the welding output voltage is large (when the arc is unstable), the change in the pulse frequency can be suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation amount, and the spatter can be suppressed.
[0017]
Next, a consumable electrode type pulse arc welding apparatus according to a sixth aspect of the present invention includes a welding condition setting unit for setting welding conditions such as a wire feeding amount or a wire diameter or a wire material, and an output of the welding condition setting unit as an input. The base current calculation section and the peak current calculation section are provided for setting upper and lower limits of a base current and a peak current according to at least one of a wire feed amount, a wire diameter, and a wire material. As a result, when the fluctuation of the welding output voltage is large (when the arc is unstable), the change in the pulse frequency can be suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation amount, and the spatter can be suppressed.
[0018]
A consumable electrode type pulse arc welding apparatus according to a seventh aspect of the present invention includes a fine adjustment unit for adjusting a set value of a base current and a peak current. As a result, when the fluctuation of the welding output voltage is large (when the arc is unstable), the change in the pulse frequency can be suppressed by increasing or decreasing the base current or the peak current in order to correct the large fluctuation amount, and the spatter can be suppressed.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
In the present embodiment, the same components as those of the conventional example are denoted by the same reference numerals, and detailed description is omitted.
[0020]
In FIG. 1, a welding voltage detecting unit 7 for detecting a welding voltage, a welding voltage setting unit 9 for setting a welding voltage, and an output of the welding voltage detecting unit 7 and an output of the welding voltage setting unit 9 are used as inputs. An error amplifier 8 for amplifying an input difference, a base current setting unit 12 for setting a base current, a peak current setting unit 15 for setting a peak current, and an output of the base current setting unit 12 and the error amplifier 8 And a base current calculator 14 for increasing and decreasing the base current according to the output of the error amplifier 8, and the output of the peak current setting unit 15 and the output of the error amplifier 8 as inputs. 8 illustrates a peak current calculation unit 16 that increases and decreases the peak current according to the output of FIG.
[0021]
The operation of the present embodiment configured as described above will be described.
[0022]
If the output voltage signal detected by the welding voltage detector 7 is larger than the set welding voltage signal set by the set welding voltage setting unit 9, the error amplifying unit 8 takes the difference and outputs the difference to the base current calculator 14. And the peak current calculator 16.
[0023]
Then, the base current calculation unit 14 and the peak current calculation unit 16 reduce at least one of the output of the base current setting unit 12 and the output of the peak current calculation unit 16 in order to reduce the welding output voltage.
[0024]
The welding output voltage detection signal may be a signal corresponding to the welding output voltage.
[0025]
As a result, the correction of the welding output voltage with respect to the set welding voltage is controlled by the pulse period and the pulse frequency, and further, by controlling the base current and the peak current, it is possible to suppress the change in the pulse frequency and to generate an irregular short circuit. And spatter can be suppressed.
(Embodiment 2)
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.
[0026]
In FIG. 2, a welding condition setting unit 17 for setting welding conditions such as a wire feeding amount, a wire diameter, and a wire material, and at least the wire feeding amount, the wire diameter, or the wire material with the output of the welding condition setting unit 17 as an input. The base current calculation unit 14 and the peak current calculation unit 16 that set the upper limit value and the lower limit value of the base current and the peak current according to one.
[0027]
The difference from the first embodiment is that the base current calculation unit and the peak current calculation unit set the upper and lower limits of the base current and the peak current according to the welding conditions.
[0028]
Thereby, spatter can be further suppressed by setting the optimum upper and lower limits for each welding condition.
(Embodiment 3)
In the present embodiment, the same components as those in Embodiments 1 and 2 are denoted by the same reference numerals, and detailed description is omitted.
[0029]
In FIG. 2, a fine adjustment unit 18 for adjusting the set values of the base current and the peak current is provided. The fine adjustment unit may be built in a controller outside the welding power source.
[0030]
Thus, the range of response can be expanded by finely adjusting the base current and the peak current under special conditions such as a special wire material or a shielding gas composition.
[0031]
【The invention's effect】
The pulse output control method and the consumable electrode type pulse arc welding machine according to the present invention suppress spatters generated when the arc becomes unstable, such as when an arc is started or when a protrusion length such as a positional deviation of a workpiece changes. And the welding quality can be improved.
[Brief description of the drawings]
FIG. 1 is a block circuit diagram of a consumable electrode arc welding apparatus of the present invention. FIG. 2 is a block circuit diagram of a consumable electrode arc welding apparatus of the present invention. FIG. 3 is a block circuit of a conventional consumable electrode arc welding apparatus. Figure [Explanation of symbols]
1, input power supply 2, first rectifier 3, inverter 4, transformer 5, second rectifier 6, reactor 7, welding voltage detector 8, error amplifier 9, welding Voltage setting unit 10, pulse output setting unit 11, pulse frequency setting unit 12, base current setting unit 13, wire feeder 14, base current calculation unit 15, peak current setting unit 16, peak current Arithmetic unit 17, welding condition setting unit 18, fine adjustment unit 22, torch 23, wire 24, base metal

Claims (7)

A set welding voltage or a signal corresponding to the set welding voltage when the peak current and the base current are repeatedly supplied in a pulsed manner between the welding wire and the welding base material and reduced from a condition in which a short circuit does not occur. The pulse period is set so as to keep the average of the pulse frequency of the current constant using the welding output voltage or the signal corresponding to the welding output voltage in the case where the welding output voltage or the signal corresponding to the welding output voltage is set. A pulse output control method characterized by increasing at least one of a base current and a peak current when the signal is lower than a signal corresponding to a welding voltage or a set welding voltage. A set welding voltage or a signal corresponding to the set welding voltage when the peak current and the base current are repeatedly supplied in a pulsed manner between the welding wire and the welding base material and reduced from a condition in which a short circuit does not occur. The pulse period is set so as to keep the average of the pulse frequency of the current constant using the welding output voltage or the signal corresponding to the welding output voltage in the case where the welding output voltage or the signal corresponding to the welding output voltage is set. A pulse output control method characterized by lowering at least one of a base current and a peak current when the signal is higher than a signal corresponding to a welding voltage or a set welding voltage. When the welding output voltage or the signal corresponding to the welding output voltage is lower than the set welding voltage or the signal corresponding to the set welding voltage, at least one of the base current and the peak current is increased. Item 3. A pulse output control method according to Item 2. The pulse output control according to any one of claims 1 to 3, wherein an upper limit value and a lower limit value of the base current and the peak current are set according to at least one of a wire feeding amount, a wire diameter, and a wire material. Method. A welding voltage detecting section for detecting a welding voltage; a welding voltage setting section for setting a welding voltage; and an error amplifier for receiving an output of the welding voltage detecting section and an output of the welding voltage setting section as inputs and amplifying a difference between the two inputs. Unit, a base current setting unit for setting a base current, a peak current setting unit for setting a peak current, and an output of the base current setting unit and an output of the error amplification unit as inputs and according to an output of the error amplification unit. A base current calculator for increasing / decreasing a base current; a peak current calculator for receiving an output of the peak current setting unit and an output of the error amplifying unit as inputs and increasing / decreasing a peak current in accordance with an output of the error amplifying unit; A consumable electrode type pulse arc welding apparatus for controlling an error amplification amount of a welding output voltage with respect to a set value as at least one of a base current and a peak current. A welding condition setting unit for setting welding conditions such as a wire feeding amount or a wire diameter or a wire material, and an output of the welding condition setting unit as an input in accordance with at least one of a wire feeding amount or a wire diameter or a wire material. The consumable electrode type pulse arc welding apparatus according to claim 5, further comprising the base current calculator and the peak current calculator for setting upper and lower limits of a base current and a peak current. The consumable electrode type pulse arc welding apparatus according to claim 5 or 6, further comprising a fine adjustment unit for adjusting a set value of the base current and the peak current.

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