JP2009262211A - Tig welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide TIG welding equipment which can optimize the feeding rate in accordance with the inserting direction of a filler wire. <P>SOLUTION: Regarding the TIG welding equipment where beforehand decided welding current Iw is made to flow between an electrode 1 and a base material 2, so as to generate an arc 3, and welding is performed while inserting a wire 4 into an arc generating part at a beforehand decided feeding rate, the equipment comprises: a wirer inserting direction set part HR where a wire inserting direction set signal Hr for setting whether the wire 4 is inserted from the front direction of the arc or the back direction of the arc to the welding direction is output; a welding current set part where a welding current set signal Ir for setting the welding current Iw is output; and a feeding rate set part FR where, with the wire inserting direction set signal Hr and the welding current set signal Ir as inputs, a feeding rate set signal Fr for setting the feeding rate is output by beforehand set functions. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a TIG welding apparatus that can optimize a feeding speed in accordance with the insertion direction of a filler wire.

  FIG. 5 is an example of a block diagram of a TIG welding apparatus using a robot. Hereinafter, each block will be described with reference to FIG.

  The welding power source PS receives a welding condition setting signal Ws from the robot controller RC, outputs a welding current Iw and a welding voltage Vw for generating the arc 3, and controls the rotation of the feed motor WM. A feed control signal Fc is output. The welding condition setting signal Ws includes a welding start signal, a welding current setting signal, a feeding speed setting signal, and the like. Since the welding power source PS is for TIG welding, it has constant current characteristics, and the welding current Iw is controlled to a predetermined value.

  The robot controller RC outputs the above-described welding condition setting signal Ws and also outputs an operation control signal Mc for controlling a servo motor (not shown) of the robot RM according to a predetermined operation program.

  A non-consumable electrode 1 (hereinafter referred to as an electrode 1) is attached to the tip of the welding torch 5, and an arc 3 is generated between the electrode 1 and the base material 2. The filler wire 4 (hereinafter referred to as the wire 4) is fed by the feeding motor WM and is placed at a predetermined position of the arc 3 generating portion by the wire insertion mechanism 6 provided at the tip of the welding torch 5. Inserted. The welding torch 5 and the feeding motor WM are mounted on the robot RM.

  As described above, in TIG welding performed while the wire 4 is being inserted, it is an indispensable requirement for good welding that the welding current Iw and the feeding speed of the wire 4 are in an appropriate relationship. That is, since the welding current Iw determines the melting rate, the welding state becomes unstable when the melting rate and the feeding rate become unbalanced. When the melting speed (welding current Iw) is faster than the feeding speed, the wire 4 burns up, and conversely when the melting speed (welding current Iw) is slow, the wire 4 hits the base material 2. For this reason, it is important to balance the melting rate (welding current Iw) and the feeding rate.

  In the invention of Patent Document 1, it is disclosed that an arc length is detected by a welding voltage Vw to automatically adjust a wire feeding speed. By changing the feeding speed according to the arc length, even if the groove processing accuracy is poor, it is possible to suppress burn-off and to obtain good welding quality.

Japanese Patent Laid-Open No. 55-8352

  FIG. 6 is a schematic diagram of an arc generator for explaining the problem of the present invention. FIG. 4A shows a case where the wire 4 is inserted from the front side of the arc, and FIG. 4B shows a case where the wire 4 is inserted from the rear side. Hereinafter, a description will be given with reference to FIG.

  In FIG. 2A, an arc 3 is generated between the electrode 1 and the base material 2. The welding direction is the right direction as shown by the arrow. The wire 4 is inserted from the front side of the arc 3 with respect to the welding direction. On the other hand, in FIG. 5B, the wire 4 is inserted from the rear side of the arc 3 with respect to the welding direction. Thus, when the insertion direction of the wire 4 is different, the melting rate is different even with the same welding current value. For this reason, when the feeding speed of the wire 4 is a constant value, if the wire insertion direction changes, the balance is lost, and the welding state becomes unstable.

  In the prior art, when a welding current is set, a function of automatically adjusting the feeding speed of the wire 4 to an appropriate value according to the setting has been used. In the prior art, when the welding current and the feeding speed are set, it is determined whether the relationship between the two values is within the proper range, and if it is out of the proper range, an alarm (lighting of the indicator lamp, alarm sound) Generation, output of alarm signals to the outside, etc.) have been commonly used. However, since these functions do not determine the wire insertion direction, they cannot be used when the wire insertion direction changes. That is, in the conventional feeding speed automatic adjustment function, when the wire insertion direction is changed, the balance between the melting speed and the feeding speed due to the welding current is lost, and the welding state becomes unstable. In addition, when the wire insertion direction changes in the prior art alarm function, the appropriate relationship between the melting rate and the feed rate due to the welding current changes, so an alarm cannot be issued even if it is outside the appropriate range. Will occur.

  Therefore, an object of the present invention is to provide a TIG welding apparatus capable of operating a feed speed automatic adjustment function and an alarm function normally even when the wire insertion direction changes.

In order to solve the above-described problem, the first invention
In a TIG welding apparatus for conducting welding while passing a predetermined welding current between an electrode and a base material to generate an arc, and inserting a wire into the arc generating part at a predetermined feeding speed,
A wire insertion direction setting unit for outputting a wire insertion direction setting signal for setting whether the wire is inserted from the arc front direction or the rear direction with respect to the welding direction;
A welding current setting unit that outputs a welding current setting signal for setting the welding current;
A feed speed setting unit that outputs a feed speed setting signal for setting the feed speed by a predetermined function with the wire insertion direction setting signal and the welding current setting signal as inputs; and
A TIG welding apparatus comprising:

According to a second aspect of the present invention, an arc is generated by applying a predetermined welding current between the electrode and the base material, and welding is performed while inserting a wire into the arc generating portion at a predetermined feeding speed. In TIG welding equipment,
A wire insertion direction setting unit for outputting a wire insertion direction setting signal for setting whether the wire is inserted from the arc front direction or the rear direction with respect to the welding direction;
A welding current setting unit that outputs a welding current setting signal for setting the welding current;
A feed speed appropriate range setting unit that sets the appropriate range of the feed speed as an input of the wire insertion direction setting signal and the welding current setting signal;
An alarm unit that issues an alarm when the feeding speed is out of the appropriate range;
A TIG welding apparatus comprising:

A third invention is a robot equipped with a welding torch;
A robot controller for operating the robot according to an operation program;
The wire insertion direction setting unit determines the wire insertion direction from the operation program and automatically sets the wire insertion direction setting signal.
This is a TIG welding apparatus according to the first or second invention.

  According to the first aspect of the invention, an appropriate feed speed setting signal can be automatically set by a predetermined function with the welding current setting signal and the wire insertion direction setting signal as inputs. For this reason, even if the insertion direction of the wire into the arc generating portion is the forward direction or the backward direction, the wire is fed at an appropriate feeding speed, so that a stable welding state can be obtained.

  According to the second aspect, an alarm can be issued when the value of the feed speed setting signal is out of the appropriate range set by the welding current setting signal and the wire insertion direction setting signal. For this reason, since an alarm is issued when the welding state becomes unstable, it is possible to accurately manage the welding quality.

  According to the third aspect, the wire insertion direction setting signal can be automatically set from the robot operation program. For this reason, even if the wire insertion direction changes for each welding point, it is not necessary to manually switch the wire insertion direction setting signal, and the production efficiency is improved.

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

[Embodiment 1]
FIG. 1 is a block diagram of a welding power source PS that constitutes a TIG welding apparatus according to Embodiment 1 of the present invention. The configuration of the TIG welding apparatus is the same as that shown in FIG. The block diagram of the welding power source PS is different from the prior art. Hereinafter, each block will be described with reference to FIG.

  The power supply main circuit PM receives a commercial power supply (not shown) such as three-phase 200 V, performs output control by inverter control according to a drive signal Dv described later, and generates a welding current Iw and a welding voltage Vw for generating the arc 3. Is output. Although not shown, the power supply main circuit PM includes a primary rectifier that rectifies commercial power, a capacitor that smoothes the rectified direct current, an inverter circuit that converts the smoothed direct current into high-frequency alternating current according to the drive signal Dv, A high-frequency transformer that steps down the high-frequency alternating current to a voltage value suitable for arc welding, a secondary rectifier that rectifies the stepped-down high-frequency alternating current, and a reactor that smoothes the rectified direct current.

  An arc 3 is generated between the electrode 1 attached to the tip of the welding torch 5 and the base material 2. The wire 4 is fed by the rotation of the feed motor WM, and is inserted from the front or rear direction into the generation part of the arc 3 by the wire insertion mechanism 6 provided at the tip of the welding torch 5.

  The welding current detection circuit ID detects the welding current Iw and outputs a welding current detection signal Id. A welding current setting signal Ir for setting the welding current Iw is input from the external robot controller RC. Therefore, the welding current setting circuit is provided inside the robot control device RC. The current error amplification circuit EI amplifies an error between the welding current setting signal Ir and the welding current detection signal Id, and outputs a current error amplification signal Ei. The drive circuit DV receives the current error amplification signal Ei as input and performs pulse width modulation control. Based on this result, the drive circuit DV outputs a drive signal Dv for driving the switching elements forming the inverter circuit of the power supply main circuit PM. Output. With these configurations, the welding apparatus has constant current characteristics.

  The wire insertion direction setting circuit HR outputs a wire insertion direction setting signal Hr that is at a high level when the wire 4 is inserted from the front direction of the arc 3 and that is at a low level when the wire 4 is inserted from the rear direction. The wire insertion direction setting circuit HR corresponds to, for example, a switch provided in the panel portion of the welding apparatus, and may be switched between a high level and a low level by turning on or off the switch. The feeding speed setting circuit FR receives the welding current setting signal Ir and the wire insertion direction setting signal Hr, calculates a feeding speed by a feeding speed setting function described later with reference to FIG. 2, and sets the feeding speed. The signal Fr is output. The feed control circuit FC receives the feed speed setting signal Fr and outputs a feed control signal Fc for controlling the feed of the wire 4 to the feed motor WM.

  FIG. 2 is a diagram illustrating an example of a feed speed setting function built in the feed speed setting circuit FR described above. In the figure, the material of the wire 4 is iron and the diameter is 1.0 mm. In the figure, the horizontal axis represents the welding current setting signal Ir (A), and the vertical axis represents the feed speed setting signal Fr (cm / min). The function f1 is when the wire insertion direction setting signal Hr is High level (insertion from the front direction), and the function f2 is when the wire insertion direction setting signal Hr is Low level (insertion from the rear direction). For the same welding current setting value, the feed speed setting value is smaller when the insertion is performed from the front direction indicated by the function f1. This is because the melting rate with the same welding current value is slower in the insertion from the front direction than in the insertion from the rear direction.

  According to the first embodiment described above, an appropriate feed speed setting signal can be set by a predetermined function with the welding current setting signal and the wire insertion direction setting signal as inputs. For this reason, even if the insertion direction of the wire into the arc generating portion is the forward direction or the backward direction, the wire is fed at an appropriate feeding speed, so that a stable welding state can be obtained.

[Embodiment 2]
FIG. 3 is a block diagram of a welding power source PS constituting the TIG welding apparatus according to Embodiment 2 of the present invention. The configuration of the TIG welding apparatus is the same as that shown in FIG. 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 broken lines different from those in FIG. 1 will be described with reference to FIG.

  The feed speed fine adjustment circuit FBR is inserted between the feed speed setting circuit FR and the feed control circuit FC in FIG. 1, and finely adjusts the value with the feed speed setting signal Fr as an input to feed the feed speed. The speed fine adjustment signal Fbr is output. The appropriate range setting circuit TR receives the feed speed setting signal Fr as described above, and outputs an upper limit value signal Fjr = Fr + ΔFr and a lower limit value signal Fkr = Fr−ΔFr with a predetermined appropriate width ΔFr. The alarm circuit AR receives the upper limit value signal Fjr, the lower limit value signal Fkr, and the feed speed fine adjustment signal Fbr, and determines that it is out of the appropriate range when Fbr> Fjr or Fbr <Fkr. , Issue an alarm. Examples of this alarm include turning on an indicator lamp, outputting an alarm sound, and outputting an alarm signal to the outside. Further, the appropriate width ΔFr may be changed between when the upper limit value is calculated and when the lower limit value is calculated. Further, the appropriate width ΔFr may be a function ΔFr = g (Ir) of the value of the welding current setting signal Ir. In the above, the appropriate range setting circuit TR receives the feed speed setting signal Fr, and the feed speed setting signal Fr receives the welding current setting signal Ir and the wire insertion direction setting signal Hr by the feed speed setting circuit FR. Is calculated as Therefore, it can be said that the appropriate range setting circuit TR is set with the welding current setting signal Ir and the wire insertion direction setting signal Hr as inputs.

  According to the second embodiment described above, when the feed speed fine adjustment signal Fbr for setting the feed speed is out of the appropriate range set by the welding current setting signal Ir and the wire insertion direction setting signal Hr. Can issue an alarm. For this reason, since an alarm is issued when the welding state becomes unstable, it is possible to accurately manage the welding quality.

[Embodiment 3]
FIG. 4 is a block diagram of a TIG welding apparatus according to Embodiment 3 of the present invention. This figure corresponds to FIG. 5 described above, and the same blocks as those in FIG. Since the internal block of the robot control device RC is different from that in FIG. 5, this point will be described with reference to FIG.

  The internal block diagram of the robot controller RC is as follows. The operation program storage circuit MM stores an operation program taught in advance and outputs the operation program. The operation control circuit MC outputs an operation control signal Mc for operating the robot RM according to the operation program, and outputs a welding current setting signal Ir included in the operation program to the interface circuit IF. The wire insertion direction setting circuit HR discriminates the wire insertion direction from the above operation program, and becomes a high level when inserted from the front direction and becomes a low level when inserted from the rear direction. Is output to the interface circuit IF. The interface circuit IF outputs a welding condition setting signal Ws including the welding current setting signal Ir and the wire insertion direction setting signal Hr to the welding power source PS. The internal block diagram of the welding power source PS is the same as FIG. 1 or FIG. 3 described above. However, the wire insertion direction setting circuit HR is moved from the inside of the welding power source PS to the robot controller RC. Therefore, the welding power source PS is supplied with the welding current setting signal Ir and the wire insertion direction setting signal Hr from the robot controller RC.

  According to the third embodiment described above, since the wire insertion direction setting signal can be automatically set from the robot operation program, it is necessary to switch the wire insertion direction setting switch or the like even if the wire insertion direction changes for each welding point. Production efficiency is improved.

  In Embodiment 3 described above, instead of automatically determining the wire insertion direction from the operation program, the wire insertion direction may be taught as one of the welding conditions on the operation program.

It is a block diagram of welding power supply PS which comprises the TIG welding apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the feed speed setting function built in the feed speed setting circuit FR in FIG. It is a block diagram of welding power supply PS which comprises the TIG welding apparatus which concerns on Embodiment 2 of this invention. It is a block diagram of the TIG welding apparatus which concerns on Embodiment 3 of this invention. It is a block diagram of the TIG welding apparatus in a prior art. It is a schematic diagram of the arc generation part for demonstrating a subject.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode 2 Base material 3 Arc 4 Wire 5 Welding torch 6 Wire insertion mechanism DV Drive circuit Dv Drive signal EI Current error amplification circuit Ei Current error amplification signal f1, f2 Function FBR Feeding speed fine adjustment circuit Fbr Feeding speed fine adjustment signal FC feed control circuit Fc feed control signal Fjr upper limit signal Fkr lower limit signal FR feed speed setting circuit Fr feed speed setting signal HR wire insertion direction setting circuit Hr wire insertion direction setting signal ID welding current detection circuit Id welding current Detection signal IF Interface circuit Ir Welding current setting signal Iw Welding current MC Operation control circuit Mc Operation control signal MM Operation program memory circuit PM Power supply main circuit PS Welding power supply RC Robot controller RM Robot TR Appropriate range setting circuit Vw Welding voltage WM Feeding Motor Ws Welding condition setting signal ΔFr Proper width

Claims (3)

In a TIG welding apparatus for conducting welding while passing a predetermined welding current between an electrode and a base material to generate an arc, and inserting a wire into the arc generating part at a predetermined feeding speed,
A wire insertion direction setting unit for outputting a wire insertion direction setting signal for setting whether the wire is inserted from the arc front direction or the rear direction with respect to the welding direction;
A welding current setting unit that outputs a welding current setting signal for setting the welding current;
A feed speed setting unit that outputs a feed speed setting signal for setting the feed speed by a predetermined function with the wire insertion direction setting signal and the welding current setting signal as inputs; and
A TIG welding apparatus comprising: In a TIG welding apparatus for conducting welding while passing a predetermined welding current between an electrode and a base material to generate an arc, and inserting a wire into the arc generating part at a predetermined feeding speed,
A wire insertion direction setting unit for outputting a wire insertion direction setting signal for setting whether the wire is inserted from the arc front direction or the rear direction with respect to the welding direction;
A welding current setting unit that outputs a welding current setting signal for setting the welding current;
A feed speed appropriate range setting unit that sets the appropriate range of the feed speed as an input of the wire insertion direction setting signal and the welding current setting signal;
An alarm unit that issues an alarm when the feeding speed is out of the appropriate range;
A TIG welding apparatus comprising: A robot with a welding torch,
A robot controller for operating the robot according to an operation program;
The wire insertion direction setting unit determines the wire insertion direction from the operation program and automatically sets the wire insertion direction setting signal.
The TIG welding apparatus according to claim 1 or 2, characterized in that

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