JP2009233739A - Welding method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding method and apparatus capable of securing high productivity and improving quality of appearance in a weld zone. <P>SOLUTION: With a planned welding part 2 faced upward, a base material 1 is inclined so that the planned welding part 2 forms a prescribed angle α with the horizontal plane H. Then, pulse welding is performed on the planned welding part 2 by moving a welding torch 21 relatively to the base material 1 along the planned welding part 2 from its upper part to the lower part. The angle formed by the planned welding part 2 and the horizontal plane is desirably about 60-90°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a welding method and a welding apparatus.

  As one of the welding methods, mixed gas welding using a mixed gas containing carbon dioxide gas or the like is widely known in general (see Patent Document 1, etc.).

JP 2005-169414 A

  However, since it is difficult to control the amount of welding in mixed gas welding, the weld bead is formed in a convex shape, and the surface of the welded bead tends to have scaly stripes. It is difficult to improve quality. Although the height of the weld bead can be suppressed to some extent by adjusting the component ratio of the mixed gas, it is difficult to suppress it to a level close to a smooth surface. On the other hand, there is a method in which the welding bead can be finished relatively smoothly by controlling the amount of welding with high accuracy as in plasma welding, but the welding operation takes about two to three times as long as mixed gas welding. Productivity is poor.

  This invention is made | formed in view of the above, and it aims at providing the welding method and welding apparatus which can improve the external appearance quality of a welding location while ensuring high productivity.

  (1) In order to achieve the above-mentioned object, the present invention is configured to incline a base material so that the planned welding portion forms a predetermined angle with respect to a horizontal plane with the planned welding portion facing upward, The welding torch is moved relative to the base material from the upper side to the lower side of the planned welding portion along the line, and the welding planned portion is pulse-welded.

  (2) In said (1), Preferably, the angle which the said welding plan part makes with respect to a horizontal surface is 60-90 degree | times.

  (3) In said (2), Preferably, the angle which the said welding plan part makes with respect to a horizontal surface is 60-75 degree | times.

  (4) In the above (3), preferably, the irradiation axis of the welding beam is inclined at a right angle with respect to the welding planned portion or on the backward side in the welding direction.

  (5) In the above (4), butt welding is preferable.

  (6) In the above (5), preferably, the base material is a side wall of a packing box of a dump truck.

  (7) In order to achieve the above-mentioned object, the present invention also provides a base for inclining and supporting a base material so that the planned welding portion forms a predetermined angle with respect to a horizontal plane with the planned welding portion facing upward. A material welding means, and a pulse welder that pulse welds the planned welding portion by moving a welding torch relative to the base material from the upper side to the lower side of the planned welding portion along the planned welding portion. Is provided.

  According to the present invention, it is possible to ensure high productivity and improve the appearance quality of the welded portion.

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

  FIG. 1 is a schematic diagram of a configuration example of a welding apparatus used in the welding method of the present invention, and FIG. 2 is a cross-sectional view of a base material taken along the line II-II in FIG.

  As shown in FIGS. 1 and 2, the welding apparatus according to the present embodiment includes a base material support means 10 that supports a base material, and a pulse welder that pulse-welds the base material 1 supported by the base material support means 10. 20.

  The base material support means 10 includes a frame 12 that can tilt with a shaft 11 as a fulcrum, and a clamp 13 provided on the frame 12. The base material 1 is fixed on the frame 12 by being pressed by a clamp 13 with the planned welding portion 2 (see FIG. 2) facing upward. When the base material 1 is fixed on the frame 12 so that the welded portion 2 is substantially orthogonal to the shaft 11, the base material 1 is viewed from the central axis direction of the shaft 11 by tilting the frame 12 about the shaft 11. It is possible to adjust an angle (base material inclination angle) α formed by one welding scheduled portion 2 with respect to the horizontal plane H within a predetermined angle range (for example, 0 to 90 degrees). Thereby, the base material 1 can be inclined and supported so that the planned welding portion 2 forms a predetermined base material inclination angle α with respect to the horizontal plane H with the planned welding portion 2 facing upward (FIG. 1). (See dotted line inside).

  In addition, the welding planned part 2 is a welding planned line extending in a straight line, and in this example, the butt part of the base material to be joined is shown as an example. However, the joint may be a joint that extends in a straight line. Although the base material 1 shown in FIG.1 and FIG.2 is a side wall of a dump truck's packing box, for example, a rear gate, the use, kind, etc. of the base material 1 are not restricted to this.

  The pulse welding machine 20 is not shown in addition to the multi-axis arm 22 that holds the welding torch 21, but a welding power source that supplies power to the welding torch 21 and outputs each command value to the welding power source to generate welding conditions (current, A welding controller that controls the voltage and speed), an arm controller that controls the operation of the multi-axis arm 22, a wire feeding device that feeds the wire to the welding torch 21, and the like. The welding controller stores spray transfer-type welding conditions in which a pulse current is superimposed on a DC background current to spray transfer droplets, and pulse welding is performed under the welding conditions.

  The multi-axis arm 22 has four axes, an xyz axis and a θ axis. The y-axis is an extending direction of the shaft 11, the x-axis is a direction parallel to the base material placement surface I of the frame 12 and perpendicular to the y-axis, and the z-axis is an axis perpendicular to the base material placement surface I. The θ axis is a rotating system having a center of rotation parallel to the axis 11.

  The multi-axis arm 22 is provided on a slider 23 that moves in the x-axis direction with respect to the frame 12, a post 24 that is erected on the slider 23, a slide arm 25 that is slidable with respect to the post 24, and a slide arm 25. The swing arm 26 and the welding torch 21 attached to the tip of the swing arm 26 are provided. The slide arm 25 moves along the post 24 in the z-axis direction, and the swing arm 26 moves along the slide arm 25 in the y-axis direction and rotates in the θ-axis direction. Accordingly, the multi-axis arm 22 adjusts the angle (beam angle) β (see FIG. 3) of the welding torch 21 with respect to the planned welding portion 2 and the distance between the welding torch 21 and the planned welding portion 2 and travels in the x-axis direction. By doing so, the welding torch 21 can be relatively moved along the planned welding portion 2, and the welding planned portion 2 can be pulse-welded in a downward slope from the upper side to the lower side.

  At this time, as shown in FIG. 3, the beam angle β is a beam irradiation axis of the base material placement surface I of the frame 12 and the beam torch 21 within a plane orthogonal to the axis 11 (a vertical plane passing through the planned welding portion 2). This is the angle between J. In this example, the beam angle β is set to 90 degrees or less, and the beam irradiation axis J is perpendicular to the welding planned portion 2 in the vertical plane passing through the planned welding portion 2 or on the backward side in the welding direction (in the direction opposite to the beam irradiation direction). Tilt toward the welding direction back side). Further, as shown in FIG. 2, the angle γ of the beam irradiation axis J with respect to the surface of the base material 1 viewed from the x-axis direction is about 90 degrees.

  In the present embodiment, using such a welding apparatus, the base material 1 is inclined so that the planned welding portion 2 forms a predetermined angle α with respect to the horizontal plane with the planned welding portion 2 facing upward, and the planned welding is performed. The welding torch 21 is moved relative to the base material 1 from the upper side to the lower side of the planned welding portion 2 along the portion 2 to perform the downward pulse welding of the planned welding portion 2.

  According to the present embodiment, the welded portion 2 is tilted and welded in the downward direction to allow the flow of the molten pool in the welding direction, so that the bead surface is smoothed. Furthermore, by making the arc into a spray form by pulse welding, it is possible to suppress the occurrence of a scale pattern and the swell of the weld bead, thereby ensuring high productivity and further improving the appearance quality of the welded portion.

  In the present embodiment, the case where welding is performed using a welding apparatus that supports downward welding as illustrated in FIG. 1 is described as an example, but the present invention is not limited thereto. Even if the welding device is not integrated with the frame 12 that rotates about the shaft 11, the base material 1 is held in an inclined posture by some fixing means, and the angle of the welding torch 21 is adjusted according to the planned welding portion 2. What is necessary is just to be able to adjust a moving direction suitably. Further, the configuration is not limited to the configuration in which the welding torch is moved with respect to the base material, the configuration in which the base material is moved with respect to the fixed welding torch and the welding torch is moved along the planned welding portion, or both are moved and the welding torch is moved. It is good also as a structure moved along a welding scheduled part.

  FIG. 4 shows a change in the height of the weld bead depending on the base material inclination angle. The value of each case 1-5 is an average value constructed 10 times under each condition.

  As shown in FIG. 4, in case 1-5, the welding current is 200A, the welding voltage is 20V, and the welding speed is 900 mm / min. Under this condition, the base metal inclination angle α is changed to 0 °, 45 °, 60 °, 70 °, and 75 °, and the downward pulse welding is performed, and the weld bead rises at that time (height from the base material surface). Was measured. The width of the weld bead is about 8 mm.

  As a result, the height of the weld bead, which was 1.20 mm when the base material inclination angle α is 0 ° (horizontal), decreases to 0.73 mm when the base material inclination angle α is 45 °, and is 60 °. Then, it further decreased to 0.25 mm. When the base material inclination angle α was in the range of 60 to 90 °, no significant change was observed in the height of the weld bead.

  From this result, it was found that the effect is particularly great when the base material inclination angle α is about 60 to 90 °. In addition, when the base material 1 is tilted to nearly 90 degrees, if the base material 1 is a long object, the height space required for the welding work increases, and the flow of the molten pool becomes larger than necessary, making control difficult. . When these things are considered, it is better that the base material inclination angle α is small as long as the effect is obtained. In this case, practically, it is considered that the base material inclination angle α is preferably about 60 to 75 °, for example, about 60 °.

It is the schematic of one structural example of the welding apparatus used for the welding method of this invention. It is sectional drawing of the base material by the II-II cross section in FIG. It is explanatory drawing of the base material inclination angle at the time of welding construction, and a beam inclination angle. It is a figure showing the change of the height of the weld bead by the base material inclination angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 To-be-welded part 10 Base material support means 11 Axis 12 Frame 13 Clamp 20 Pulse welding machine 21 Welding torch 22 Multi-axis arm 23 Slider 24 Post 25 Slide arm 26 Swing arm I Base material mounting surface J Beam irradiation axis α Base material tilt angle β Beam angle γ Angle

Claims (7)

Inclining the base material so that the planned welding portion forms a predetermined angle with respect to the horizontal plane with the planned welding portion facing upward,
A welding method comprising pulse welding the planned welding portion by moving a welding torch relative to the base material from the upper side to the lower side of the planned welding portion along the planned welding portion.   The welding method according to claim 1, wherein an angle formed by the planned welding portion with respect to a horizontal plane is 60 to 90 degrees.   The welding method according to claim 2, wherein an angle formed by the planned welding portion with respect to a horizontal plane is 60 to 75 degrees.   4. The welding method according to claim 3, wherein an irradiation axis of a welding beam is inclined at a right angle or a backward direction in the welding direction with respect to the planned welding portion.   5. The welding method according to claim 4, wherein the welding method is butt welding.   6. The welding method according to claim 5, wherein the base material is a side wall of a dump car box. A base material supporting means for supporting the base material by inclining the base material so that the planned welding portion forms a predetermined angle with respect to a horizontal plane with the planned welding portion facing upward;
A pulse welding machine for pulse welding the planned welding portion by moving a welding torch relative to the base material from the upper side to the lower side of the planned welding portion along the planned welding portion; Features welding equipment.

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