JP2009018314A - Nonconsumable electrode arc welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide nonconsumable electrode arc welding equipment which easily maintains an arc length to a proper value by solving problems that a proficient skill is required to weld while maintaining a welding torch such that the arc length becomes the proper value at all times, and moreover the arc length is hard to check visually due to restraint of a work shape, in nonconsumable electrode arc welding manually performed by a welding operator. <P>SOLUTION: In the nonconsumable electrode arc welding equipment which outputs a welding current Iw and a welding voltage Vw to generate an arc 3 between a nonconsumable electrode 1 and a base material 2, the welding equipment includes a voltage detecting means VD to detect the welding voltage Vw, a sound frequency setting portion FR, and a sound outputting means SD to generate a sound having a set frequency Fr. The sound frequency setting portion sets the frequency Fr of the sound which increases or decreases according to the welding voltage Vw using a detected welding voltage value Vd as an input. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a non-consumable electrode arc welding apparatus for maintaining an arc length at an appropriate value.

  In non-consumable electrode arc welding such as TIG welding and plasma arc welding, it is necessary to perform welding while maintaining the arc length at an appropriate value in order to obtain good welding quality. In non-consumable electrode arc welding, the arc length is the distance between the tip of the non-consumable electrode (hereinafter referred to as an electrode) and the base material, so in robot welding, the arc length is set according to teaching. be able to. Even in the case of an automatic welding apparatus having a mechanism for moving the welding torch in the vertical direction, it is possible to set the arc length to an appropriate value by this vertical movement mechanism.

  In automatic welding such as robot welding, there is a case where the arc length does not become a set appropriate value due to a dimensional error of a workpiece, an installation deviation or the like. In such a case, a method is commonly used in which the arc length is detected and the welding torch is moved up and down by feedback control to change the arc length to an appropriate value. At this time, it is common to use a welding voltage as a method of detecting the arc length. This is because the arc length and the welding voltage are in a substantially proportional relationship. In addition, as a method other than this, in TIG welding performed while feeding the filler wire, a method of detecting the time during which the filler wire is in contact with the molten pool at a predetermined time has been proposed. This is because there is a substantially proportional relationship between the arc length and the contact time. There has also been proposed a method of issuing an alarm when the arc length becomes too short and finally comes into contact with the base material. When the number of contacts between the electrode and the base material increases during welding, the welding quality is extremely deteriorated. Therefore, when such a situation occurs, an alarm is issued to prompt the user to cancel the contact. See Patent Documents 1 to 3 as the above-described conventional technology.

JP-A-11-309577 JP 2001-259840 A JP 2001-300759 A

  Non-consumable electrode arc welding methods often involve welding by a welding operator holding a welding torch by hand (hereinafter referred to as manual welding). In this manual welding, the arc length is maintained at an appropriate value while visually observed. This requires skilled skills. Further, depending on the shape of the workpiece, it may be difficult to visually observe the arc length.

  When trying to improve the above problem by the conventional technique, even if it is attempted to perform feedback control by detecting the arc length, it cannot be applied because there is no means for moving the welding torch in the vertical direction.

  Therefore, an object of the present invention is to provide a non-consumable electrode arc welding apparatus that can easily maintain an arc length at an appropriate value in manual welding.

In order to solve the above-described problem, the first invention
In a non-consumable electrode arc welding apparatus that outputs a welding current and a welding voltage for generating an arc between a non-consumable electrode and a base material,
Voltage detection means for detecting the welding voltage;
A sound frequency setting unit that sets a frequency of a sound that increases or decreases in accordance with the welding voltage value with the welding voltage detection value as an input,
Sound output means for playing a sound having the set frequency;
This is a non-consumable electrode arc welding apparatus.

The second invention is
When the welding voltage detection value is outside the appropriate range, an alarm determination unit that outputs an alarm signal,
The non-consumable electrode arc welding apparatus according to the first aspect, wherein the sound frequency setting unit sets the frequency of the sound to a predetermined alarm frequency when the alarm signal is input.

  According to the first aspect, in manual welding, when the arc length changes, the welding voltage changes, so the frequency of the sound output during welding changes. For this reason, the welding operator can distinguish the change in arc length during welding by the sound of the sound, and it becomes easy to maintain the arc length constant. In addition, if the sound of the sound when the arc length for the workpiece reaches an appropriate value is confirmed by test welding, the arc length can be adjusted by operating the welding torch up and down so that the sound of the sound is obtained during construction. It can be easily set to an appropriate value. Furthermore, even when it is difficult to visually confirm the arc length due to restrictions on the workpiece shape, the arc length can be maintained at an appropriate value with the target of sound. Further, when the first invention is used for automatic welding, the variation in arc length during welding can be easily determined by the sound of the sound, which is effective for monitoring the arc state.

  Further, according to the second invention, when the welding voltage (arc length) is within the proper range, the same effect as the first invention is obtained, and when the welding voltage is outside the proper range, the predetermined alarm frequency is used. Play a sound. For this reason, it is possible for the welding operator to easily determine from the sound that the welding voltage is outside the proper range.

  Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1]
FIG. 1 is a block diagram of a non-consumable electrode arc welding apparatus according to Embodiment 1 of the present invention. The figure illustrates the case where the non-consumable electrode arc welding apparatus is a TIG welding apparatus, but the same applies to a plasma arc welding apparatus. Hereinafter, each block will be described with reference to FIG.

  The welding power source PS is a welding power source for TIG welding having a general constant current characteristic, and outputs a set welding current Iw. An arc 3 in which a welding current Iw is energized is generated between an electrode 1 such as tungsten mounted on the tip of the welding torch 4 and the base material 2, and a welding voltage Vw is applied.

  The voltage detection circuit VD detects the welding voltage Vw and outputs a voltage detection signal Vd. In TIG welding, a high-frequency high voltage is applied between the electrode 1 and the base material 2 at the time of arc start, and this voltage detection circuit VD has a built-in capacitor for bypassing the high-frequency high voltage.

  As will be described later with reference to FIG. 2, the sound frequency setting circuit FR has a built-in function f = g (Vw) of the sound frequency f that increases in accordance with the welding voltage value Vw. A sound frequency setting signal Fr is output by this function as an input. FIG. 2 is a diagram illustrating an example of a function f = g (Vw) for setting the sound frequency f. In the figure, the horizontal axis indicates the welding voltage Vw, and the vertical axis indicates the frequency f of the sound. In the figure, as the welding voltage Vw increases, the frequency f gradually increases (high frequency). In the function for setting this sound, the frequency f may decrease (lower frequency) as the welding voltage Vw increases. Moreover, it is not necessary to increase or decrease linearly, and it may be curved or stepped. However, the welding voltage Vw is in the range of an arc voltage (for example, 10 to 40 V), and the frequency f is set so as to change in the audible range corresponding to the arc voltage range.

  The sound output circuit SD always plays a sound having the frequency f set by the sound frequency setting signal Fr during welding. The voltage detection circuit VD, the sound frequency setting circuit FR, and the sound output circuit SD may be built in the welding power source PS or may be installed as a sound device outside.

  According to the first embodiment described above, in manual welding, when the arc length changes, the welding voltage changes, so the frequency of the sound output during welding changes. For this reason, the welding operator can distinguish the change in arc length during welding by the sound of the sound, and it becomes easy to maintain the arc length constant. In addition, if the sound of the sound when the arc length for the workpiece reaches an appropriate value is confirmed by test welding, the arc length can be adjusted by moving the welding torch up and down so that the sound of the sound is obtained during construction. It can be easily set to an appropriate value. Furthermore, even when it is difficult to visually confirm the arc length due to restrictions on the workpiece shape, the arc length can be maintained at an appropriate value with the target of sound. Moreover, when this Embodiment 1 is used for automatic welding, the fluctuation of the arc length during welding can be easily discriminated by the sound of the sound, which is effective for monitoring the arc state.

[Embodiment 2]
FIG. 3 is a block diagram of a non-consumable electrode arc welding apparatus according to Embodiment 2 of the present invention. In the figure, the same blocks as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof is omitted. Hereinafter, blocks indicated by dotted lines different from those in FIG. 1 will be described.

  The current detection circuit ID detects the welding current Iw and outputs a current detection signal Id. The alarm determination circuit AR receives the current detection signal Id and the voltage detection signal Vd, determines that the voltage detection signal Vd is out of the proper range, as will be described later with reference to FIG. Output. FIG. 4 is an arc characteristic diagram illustrating a method for determining that the welding voltage Vw is out of the proper range. In the figure, the horizontal axis represents the welding current Iw, and the vertical axis represents the welding voltage Vw. The characteristic Lu is the arc characteristic when the arc length is the upper limit value of the appropriate range, and the characteristic Ld is the arc characteristic when the arc length is the lower limit value of the appropriate range. Therefore, the range sandwiched between the two characteristics is the range in which the arc length is appropriate. When the value of the current detection signal is Id1 and the value of the voltage detection signal is Vd1, if the intersection (operating point) P1 is within the above appropriate range, the arc length is within the appropriate range, and the voltage detection signal Vd1 is also Within the appropriate range. On the other hand, when the operating point P1 is outside the proper range, the arc length is outside the proper range, and the voltage detection signal Vd1 is also outside the proper range. In this way, it can be determined that the welding voltage Vw is outside the proper range. A welding current setting signal in the welding power source PS may be used instead of the current detection signal Id. Since the welding power source PS for non-consumable electrode arc welding has a constant current characteristic, the value of the current detection signal Id and the value of the welding current setting signal are the same value. In this case, it is not necessary to add a current detection circuit ID.

  The alarm frequency setting circuit FA outputs an alarm frequency setting signal Fa that is a sound frequency at the time of an alarm. When the alarm signal Ar is not input, the second sound frequency setting circuit FR2 outputs a sound frequency setting signal Fr that changes according to the voltage detection signal Vd as in the case of FIG. When the alarm signal Ar is input, the value of the alarm frequency setting signal Fa is output as the sound frequency setting signal Fr.

  FIG. 5 is a diagram showing a function for setting the sound frequency f. In the figure, the horizontal axis indicates the welding voltage Vw, and the vertical axis indicates the frequency f of the sound. This figure corresponds to FIG. 2 described above. As in FIG. 2, the function g (Vw) increases the frequency f as the welding voltage Vw increases. On the other hand, the function h (Vw) becomes a constant value Fa regardless of the value of the welding voltage Vw. This Fa becomes the value of the alarm frequency setting signal. In the figure, when the alarm signal Ar is not inputted, the value of the sound frequency setting signal Fr is calculated by the function g (VW), and when the alarm signal Ar is inputted, the sound is obtained by the function h (Vw). The value of the frequency setting signal Fr is calculated.

  The alarm frequency Fa is preferably set outside the frequency range of the function g. This is because it can be easily determined that the alarm signal Ar is input. In FIG. 4, when the value of the alarm signal Ar is made different depending on whether the welding voltage Vw exceeds the upper limit value of the appropriate range or falls below the lower limit value, the value of the alarm frequency Fa also corresponds to this. The two may be set so that they can be distinguished.

  According to the second embodiment described above, when the welding voltage (arc length) is within the proper range, the same effect as in the first embodiment is obtained, and when the welding voltage is outside the proper range, the predetermined alarm frequency is used. Play a sound. For this reason, it is possible for the welding operator to easily determine from the sound that the welding voltage is outside the proper range.

  In the above-described embodiment, the TIG welding apparatus has been described, but the same applies to the plasma arc welding apparatus. In the embodiment described above, the frequency of the sound is changed, but the volume, the short sound repetition period, a combination thereof, and the like may be changed. The sound output circuit SD may be disposed on the welding torch so that it can be heard by welding workers. In addition, instead of the sound output circuit SD, an indicator such as an LED may be used to change the blinking cycle according to the welding voltage.

It is a block diagram of the non-consumable electrode arc welding apparatus which concerns on Embodiment 1 of this invention. FIG. 6 is a diagram showing a setting function of a sound frequency f with respect to a welding voltage Vw in the first embodiment. It is a block diagram of the non-consumable electrode arc welding apparatus which concerns on Embodiment 2 of this invention. It is an arc characteristic view showing a method for discriminating that the welding voltage Vw in the second embodiment is out of the proper range. FIG. 10 is a diagram showing a setting function of a sound frequency f with respect to a welding voltage Vw in the second embodiment.

Explanation of symbols

1 (Non-consumable) Electrode 2 Base material 3 Arc 4 Welding torch AR Alarm discrimination circuit Ar Alarm signal f Sound frequency FA Alarm frequency setting circuit Fa Alarm frequency (setting signal)
FR sound frequency setting circuit Fr sound frequency setting signal FR2 second sound frequency setting circuit g (sound frequency setting) function h (sound frequency setting) function ID current detection circuit Id current detection signal Iw welding current Ld arc characteristic Lu arc characteristic P1 operation Point PS Welding power supply SD Sound output circuit VD Voltage detection circuit Vd Voltage detection signal Vw Welding voltage

Claims (2)

In a non-consumable electrode arc welding apparatus that outputs a welding current and a welding voltage for generating an arc between a non-consumable electrode and a base material,
Voltage detecting means for detecting the welding voltage;
A sound frequency setting unit that sets the frequency of the sound that increases or decreases according to the welding voltage value as an input of the welding voltage detection value;
Sound output means for playing a sound having the set frequency;
A non-consumable electrode arc welding apparatus comprising: When the welding voltage detection value is outside the appropriate range, an alarm determination unit that outputs an alarm signal,
The non-consumable electrode arc welding apparatus according to claim 1, wherein when the alarm signal is input, the sound frequency setting unit sets the frequency of the sound to a predetermined alarm frequency.

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