Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K9/00—Arc welding or cutting
  • B23K9/10—Other electric circuits therefor; Protective circuits; Remote controls
  • B23K9/1006—Power supply
  • B23K9/1043—Power supply characterised by the electric circuit
  • B23K9/1056—Power supply characterised by the electric circuit by using digital means
  • B23K9/1062—Power supply characterised by the electric circuit by using digital means with computing means

Definitions

• the present invention relates to a carbon dioxide gas arc welding method, and more particularly, to a high-speed welding of about 1.5 mZ or more using a power supply having a control to open a short circuit at least about 500 AZmsec when a short circuit is detected.
• the present invention relates to a high-speed carbon dioxide gas arc welding method in which the voltage is higher than the buried arc area ⁇ humming 'fusing area, and the droplets transfer almost uniformly with almost no short circuit.
• High-speed carbon dioxide welding in which the welding speed is increased from about one minute to high-speed welding, results in high-speed, large-current welding, making it impossible to ignore the effect of electromagnetic pressure caused by the electromagnetic force of the arc itself, and beading the effect It is also reflected in the formation, the surface of the weld pool is depressed by its action, and a gouging head area is formed in which the bottom or the periphery of the weld pool is exuded. Further, when the action of the arc pressure becomes strong, that is, when the current becomes large, the gouging region expands, and finally the solidification proceeds without being sufficiently filled by the exposed portion, and there is a problem that a sander cut and a humping bead are generated. .
• the buried arc method which has a lower welding voltage than the original welding voltage and a shorter arc length, is used to suppress the generation of large-grain spatter and to reduce the undercut It is generally said that it has the effect of suppressing bing beads.
• the occurrence of large-grain spatter can be suppressed to some extent even if the buried arc method with a reduced arc length is adopted.
• the arc heat source is buried inside the base metal from the base material surface, the deep penetration occurs.
• the welding speed is high and the welding current is large, so the aforementioned gouging area is widened, solidification progresses around the molten pool, undercuts and bumping beads are generated, and the weld joints are formed as shown in Fig. 8.
• the penetration shape is narrow and deep at the penetration depth, the bead surface is wide and a convex bead, and it has a shape with cracks (mushroom-like shape) in between, and a smooth bead penetration like MAG welding Only-The surface shape could not be obtained, and there was a problem with the weld S quality that significantly deteriorated the notch toughness of the joint.
• the present invention solves the above-mentioned problem, and adopts an open arc method instead of a buried arc method in which the arc length is shortened by high-speed carbon dioxide gas welding of about 1.5 mZ or more, and adopts an appropriate welding method.
• claim 1 of the present invention performs welding at a welding speed of about 1.5 mZ or more, and opens a short circuit at least about 500 AZmsec when a short circuit is detected.
• a formula that expresses the relationship between the welding wire feed speed and welding voltage and the volume of droplets that melts and transfers to the weld pool, and the wire feed speed, welding voltage, and the welding wire melts into the weld pool It is characterized by calculating the welding voltage according to the appropriate droplet volume using an expression that expresses the relationship with the transition period, and performing welding with the appropriate droplet volume under the obtained welding conditions. is there.
• Claim 2 of the present invention provides an appropriate droplet by an expression representing the relationship between the wire feed speed, the welding voltage, and the droplet volume, and an expression representing the relationship between the wire feed speed, the welding voltage, and the droplet transfer cycle.
• Claim 3 of the present invention provides an appropriate solution by using an expression representing the relationship between the wire feed speed, the welding pressure, and the droplet volume, and an expression representing the relationship between the wire feed speed, the welding voltage, and the droplet transfer cycle.
• V W welding voltage
• W range droplet volume
• W welding voltage
• Vf welding wire feed speed
• Claim 4 of the present invention provides a method for determining a proper quotient by using an equation representing the relationship between the wire feed speed, the welding voltage and the droplet volume and an expression representing the relationship between the wire feed speed, the welding voltage and the droplet transfer cycle.
• the buried arc region where the arc is generated inside the molten pool and the region where the base material is broken or welding is not stable are determined in advance by experiments. According to claim 1.
• Claim 5 of the present invention uses a welding wire diameter of 1.2 mm, a welding speed of approximately 2.5 mZ, and a welding wire feed speed (Vf) of 18 to 20 mZ. ranges, a range droplet volume (W) is 3. Omm 3 ⁇ 4. 5 mm 3, droplet transfer cycle (Td) 9ms e C ⁇ 1 2m S range der of ec. is, welding When calculating the welding voltage (Vw) using the wire feed speed and welding speed as inputs, so that the volume of the droplet is almost constant,
• Claim 6 of the present invention uses a welding wire diameter of 1.2 mm, a welding speed of about 2 m minutes, and a welding wire feeding speed (V f) of 15 ( ⁇ minutes to 17 mZ minutes).
• the droplet volume (W) is in the range of 3.0 mm3 to 4.5 mm3
• the droplet transition period (Td) is in the range of 1 Oms ec to 15 ms ec
• the welding wire feed speed Using the welding speed as an input, when calculating the welding voltage (Vw) so that the volume of the droplet is almost constant
• any one of the first to sixth aspects wherein welding is performed by a welding device including a robot control device.
• FIG. 1 is a graph showing a welding stable region at a welding speed of 2.5 mZ according to the present invention.
• FIG. 2 is a graph showing the relationship between welding voltage and droplet volume at a welding speed of 2.5 mZ according to the present invention.
• FIG. 3 is a graph showing the relationship between the welding voltage and the droplet transfer cycle at a welding speed of 2.5 mZ according to the present invention.
• FIG. 4 is a graph showing a buried arc region, a humming region, and a break region at a welding speed of 2.5 mZ according to the present invention.
• FIG. 5 is a block diagram showing the configuration of the welding device according to the present invention.
• FIG. 6 is a diagram showing a welding current waveform and a welding voltage waveform according to the present invention.
• FIG. 7 shows a welding current waveform and a welding voltage waveform (enlarged view) according to the present invention.
• Fig. 8 is an explanatory diagram of the bead penetration shape at the conventional welding speed of 2.5mZ.
• FIG. 9 is an explanatory diagram of a bead penetration shape at a welding speed of 2.5 mZ according to the present invention.
• FIG. 10 is a block diagram showing a configuration of a welding device including a mouth pot control device according to the present invention.
• FIG. 4 shows a high-speed carbon dioxide gas welding region represented by a welding wire feeding speed and a welding voltage at a welding speed of 2.5 mZ according to the present invention.
• FIG. 2 is a diagram showing the relationship between welding voltage and droplet volume at a welding speed of 2.5 mZ according to the present invention.
• FIG. 3 is a diagram showing a relationship between a welding voltage and a droplet transfer period at a welding speed of 2.5 mZ according to the present invention.
• FIG. 4 is a diagram showing a welding region, a buried arc region, a humming region, and a tear region of the present invention at a welding speed of 2.5 mZ.
• FIG. 5 shows a welding apparatus for performing the method of the present invention
• 1 is a welding condition setting device
• 2 is a power supply having a control for opening a short circuit at least about 500 A / msec when a short circuit is detected
• 3 is a power supply.
• the welding wire feeder 4 calculates the welding voltage according to the appropriate droplet volume with a welding voltage calculator.
• Fig. 2 shows the waveforms of the welding current and welding voltage in the welding of the present invention (Fig. 7 is an enlarged view). It can be determined that short-circuiting with a long droplet detachment time has hardly occurred. In other words, the droplet formed at the tip of the welding wire hardly short-circuits with the base metal, and moves at a substantially constant period as shown in Fig. 7, meaning that stable welding is performed. I do.
• a welding speed and a welding wire feed speed for performing a desired welding are selected, and a welding voltage according to an appropriate droplet volume is calculated by a welding voltage calculator 4.
• the welding wire feeder 3 sends the welding wire to the base metal according to the set welding wire feeding speed, and the welding power source 2 arcs between the welding wire and the base metal according to the set welding voltage. Is generated, and a welding torch moving device (not shown) moves the welding torch according to the set welding speed to perform welding.
• the droplet grows to the appropriate volume corresponding to the wire feed speed and welding voltage (after a proper period has elapsed), the droplet detaches mainly due to the electromagnetic pinch force acting on the droplet and moves to the molten pool.
• the arc shape is an open arc
• the melting position at the wire tip is a peri-arc on the base metal surface, so the penetration width is wide, and the heat input to the base material is diffused and the penetration is shallow. Become.
• the welding speed is approximately 1.5 mZ or more, the use of the welding method of the present invention stabilizes droplet transfer and suppresses spatter.
• FIG. 8 shows a conventional bead penetration shape at a welding speed of 2.5 mZ
• FIG. 9 shows a bead penetration shape according to the present invention.
• a welding wire having a welding wire diameter of 1.2 mm is used, an appropriate droplet volume is in a range of 3.0 mm3 to 4.5 mm3, and a droplet transfer cycle is 9 msec.
• the welding voltage is set in the range of ⁇ 12 ms ec, and the equation representing the relationship between the wire feed rate, welding voltage, and droplet volume and the equation representing the relationship between the wire feed rate, welding voltage, and droplet transfer cycle are used. Calculate and perform welding.
• the welding speed is 2.5 mZ
• the welding wire feed speed is in the range of 15 to 20 mZ
• the droplet volume is in the range of 3.0 mm3 to 4.5 mm3, and the droplet transfer is performed.
• the cycle is in the range of 9 ms ec 15 ms ec
• the droplet volume is w (mm 3)
• the droplet transition period is T d (ms ec)
• the welding wire feed speed is V f (mZm in)
• the welding is performed.
• Vw (V) the droplet volume and droplet transfer cycle are as shown in Figs. 2 and 3.
• a buried arc region where an arc is generated inside a molten pool and a region where a base material is broken or welding is not stable are determined in advance by experiments.
• Figure 4 shows the above-mentioned region at a welding speed of 2.5 mZ.
• the welding speed and the welding wire feed speed for performing the desired welding are selected so as not to be in the above-mentioned region, and the expression representing the relationship between the wire feed speed, the welding voltage and the droplet volume and the wire feed speed, Welding is performed by calculating the welding voltage according to the appropriate droplet volume using an expression that expresses the relationship between the welding voltage and the droplet transfer cycle.
• a fifth embodiment will be described.
• the transfer of droplets according to the present embodiment will be described.
• Fig. 3 the circumference where the droplets separate from the tip of the welding wire and migrate to the base metal The period (hereinafter referred to as the droplet transfer cycle) is almost constant.
• the volume of the droplet that separates from the tip of the welding wire and migrates to the base metal (hereinafter referred to as the droplet volume) is almost constant.
• Fig. 6 shows the waveforms of the welding current and welding voltage in the welding of the present invention, but almost no short circuit occurred.
• the droplet formed at the tip of the welding wire does not short-circuit with the base metal and moves at a substantially constant cycle as shown in Fig. 7, meaning that stable welding is performed. I do.
• the droplet volume is w (mm 3)
• the droplet transition period is Td (msec)
• the welding wire feed speed is V f (mZm ⁇ ⁇ )
• the welding voltage is Vw (V)
• the droplet volume and droplet are The transition cycle is
• the welding wire feeder 3 sends the welding wire to the base metal according to the set welding wire feed speed, and the welding power source 2 generates an arc between the welding wire and the base metal according to the set welding voltage.
• the welding torch moving device (not shown) moves the welding torch in accordance with the welding speed, and the desired welding is performed.
• a sixth embodiment will be described.
• a welding wire having a welding wire diameter of 1.2 mm was used, and the droplet volume was made substantially constant at 3.0 mm3 to 4.5 mm3. Calculate and perform welding.
• the welding speed is 2.5 m
• the welding wire feed speed is in the range of 18 to 20 mZ
• the droplet volume is in the range of 3.0 mm3 to 4.5 mm3
• the droplet transfer is performed. If the period is in the range of 9 ms ec to 15 ms ec, equations (3) and (4) are
• the welding speed is 2.Om/min
• the welding wire feed speed is in the range of 15 to 17mZ
• the droplet volume is in the range of 3.0mm3 to 4.5mm3
• the droplet transfer cycle Is in the range of 1 Oms ec to 15 ms ec
• FIG. 10 shows a welding apparatus according to the ninth embodiment.
• a welding speed and a welding wire feeding speed for performing a desired welding are selected, and a welding voltage corresponding to an appropriate droplet volume is calculated by a welding voltage calculator 4.
• the welding wire feeder 3 sends the welding wire to the base material according to the set welding wire feed speed, and the welding power source 2 generates an arc between the welding wire and the base material according to the set welding voltage.
• the robot 6 controlled by the robot controller 5 according to the set welding speed moves the gripping welding torch to perform desired welding.
• the present invention is useful as a high-speed carbon dioxide gas arc welding method.

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Arc Welding Control (AREA)
• Arc Welding In General (AREA)

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• 2000
  • 2000-03-01 JP JP2000056229A patent/JP2001246470A/ja not_active Abandoned
• 2001
  • 2001-03-01 US US10/204,436 patent/US6872915B2/en not_active Expired - Fee Related
  • 2001-03-01 WO PCT/JP2001/001572 patent/WO2001064382A1/ja not_active Ceased

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