JP3759008B2 - Welding method of cylindrical body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding method for forming a cylindrical body by welding butt portions of both end edges of a workpiece obtained by bending a plate body into a cylindrical shape in advance.
[0002]
[Prior art]
Conventionally, in order to form a cylindrical body from a plate body, first, the plate body is bent into a cylindrical shape, and the butted portions of both end edges produced by the bending process are welded from the outside or the inside, or both are welded simultaneously. Yes.
[0003]
[Problems to be solved by the invention]
However, since the interval between the butted portions to be welded is very small, when this butted portion is welded from the outside, the welded portion does not reach the inner surface, and so-called back beat cannot be made.
[0004]
Thus, if the welded portion does not reach the inner surface, the strength of the seam is weakened, and there is a problem that reliability is lacking when high strength is required as a cylindrical body.
[0005]
Moreover, when welding a thick plate body, there is a method of performing a groove processing in which the butt portion is cut in a predetermined shape in advance, but it is necessary to perform pre-processing in advance, which reduces workability. There was a problem.
[0006]
The present invention has been made in view of the above-described problems, and the purpose of the present invention is to hold and weld the butted portion at an interval sufficient to form the back beat when welding the butted portion. An object of the present invention is to provide a welding method for forming a cylindrical body excellent in strength without performing pretreatment such as groove processing.
[0007]
[Means for Solving the Problems]
Welding method of the cylindrical body of the invention according to claim 1 is a welding method of forming a cylindrical body by welding the butted portion of both end edges of the processed workpiece bending in advance the cylindrical plate member, the diameter of the workpiece And a guide member having a slit formed on the upper surface thereof, and disposed above the guide member, and can be inserted into the gap between the butting portions of the workpiece through the slit and in the workpiece feeding direction. An interval holding means having a plurality of insertion blades arranged in a freely circulating manner, and by adjusting the amount of insertion of the tip of the insertion blade inserted into the gap of the workpiece, a back beat can be formed on the inner surface of the workpiece as much as possible. of holding the gap a predetermined distance, while the circulation rate of the inserted blade is synchronized with the feed speed of the workpiece in this state, towards the workpiece to the welding torch through the insertion hole of the guide member Feed, characterized by MIG welding or MAG welding the gap.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a side view showing a schematic configuration of a welding apparatus for carrying out the cylindrical body welding method of the present invention.
[0012]
This welding apparatus forms a cylindrical body by welding abutting portions W1 (see FIG. 2) at both ends of the workpiece W, and the workpiece W is axially viewed by a feeding means such as a pusher (not shown). In FIG. 1, it can be fed in the direction of the arrow P on the left side.
[0013]
The workpiece W is obtained by bending a plate body into a cylindrical shape in advance as shown in FIG. 2. By bending the cylindrical body into a cylindrical shape in this way, the outer periphery has the above-mentioned predetermined interval L in the axial direction. A butting portion W1 having a gap is formed. The gap L is set in advance according to the material of the workpiece W, the pipe diameter, or the like so that a back bead can be formed on the inner surface of the abutting portion W1 in MIG welding or MAG welding described later.
[0014]
On the other hand, a welding torch 1 is arranged on the downstream side in the feed direction of the workpiece W, and the butting portion W1 of the workpiece W is MIG welded or mag welded by the welding torch 1. Specifically, for example, while supplying a welding wire (not shown) to the welding torch 1, welding is performed by generating an arc between the welding wire and both end edges of the abutting portion W <b> 1 of the workpiece W as a base material.
[0015]
Further, on the upstream side in the feed direction of the workpiece W, a spacing holding means 2 for feeding the workpiece W toward the welding torch 1 in a state where the gap of the abutting portion W is firmly held at the spacing L is provided. .
[0016]
This interval holding means 2 is formed by connecting a plurality of insertion blades 21 in an annular shape, and these insertion blades 21 are configured to circulate on a vertical plane. Specifically, for example, the plurality of insertion blades 21 are continuously connected to the chain 3 wound around the left and right sprockets (not shown), and the chain 3 is circulated in the arrow Q direction by a drive motor (not shown). I try to drive it.
[0017]
Of the plurality of insertion blades 21, the insertion blade 21 group disposed on the lower side is disposed so as to be inserted into the gap of the abutting portion W <b> 1 of the workpiece W fed toward the torch 1. The circulation speed is synchronized with the feed speed of the workpiece W and is circulated.
[0018]
On the other hand, as shown in FIG. 3, the cross-sectional shape of each insertion blade 21 is such that the distal end portion 22 is formed into a gradually narrowed taper portion, and the tapered distal end portion 22 is inserted into the gap of the abutting portion W1. Thus, the height position of the group of insertion blades 21 arranged on the lower side with respect to the workpiece W is set in advance so as to maintain the gap L.
[0019]
Further, as described above, the interval holding means 2 that is circulated is provided so as to be movable up and down with respect to the workpiece W by a lifting device (not shown). Therefore, the amount of insertion of the distal end portion 22 of the insertion blade 21 with respect to the abutting portion W1 of the workpiece W can be made variable by raising and lowering the interval holding means 2 by the elevating device, whereby the gap L between the abutting portions W1 is set. It is possible to cope with different workpieces W and workpieces W having different pipe diameters.
[0020]
Further, as shown in FIGS. 1 and 4, a guide member 4 is provided on the outer periphery of the work W to guide the work W without deviation along the feeding direction. Specifically, as shown in FIG. 4, the guide member 4 has a cylindrical insertion hole 41 having a size corresponding to the diameter of the workpiece W formed in the feeding direction, and the workpiece W is inserted into the insertion hole 41. By inserting from the upstream side in the feed direction and feeding by a pusher or the like, the workpiece W is conveyed toward the welding torch 1 while holding the entire workpiece W. A slit 42 having a predetermined width is formed on the upper surface of the guide member 4 in the feeding direction, and the interval holding means 2 is inserted into the gap of the workpiece W through the slit 42. Further, the downstream portion of the slit 42 facing the welding torch 1 is formed wide so as not to hinder the welding of the workpiece W.
[0021]
Next, the cylindrical body welding method of the present invention performed by the welding apparatus configured as described above will be described.
[0022]
First, the plate body is bent to form a cylindrical workpiece W. At this time, an abutting portion W1 is formed on the outer peripheral surface of the work W in the axial direction so that both end edges of the plate face each other. The butting portion W1 has a back beat on the inner surface side by MIG welding or MAG welding. It is processed in advance so as to be an appropriate interval that can be formed.
[0023]
Then, the workpiece W is arranged on the upstream side in the feeding direction of the welding apparatus so that the butting portion W1 is located at the top, and is fed in the axial direction from the upstream side toward the welding torch 1 on the downstream side. The portion W1 is MIG welded or MAG welded while supplying a welding wire from the front end in the feed direction by the welding torch 1.
[0024]
At this time, the workpiece W is inserted into the insertion hole 41 of the guide member 4 while the distal end portions 22 of the insertion blade 21 group that circulates in synchronization with the feed speed of the workpiece W are sequentially inserted from the front end side of the abutting portion W1. Sent through. Thus, by inserting the distal end portion 22 of each insertion blade 21 into the gap between the butting portions W1, the gap L between the butting portions W1 can be firmly held by the respective insertion blades 21. In this state, the guide member Since the front end of the workpiece W is sent to the welding torch 1 through the four insertion holes 41, MIG welding or mag welding by the welding torch 1 is performed while the interval L is properly maintained.
[0025]
As a result, the entire butted portion W1 is uniformly welded from the outer surface side to the inner surface side as shown in FIG. 5, and as a result, the back beat W2 is also formed on the inner surface side of the seam formed by welding.
[0026]
Further, the insertion blade 21 has a function of properly maintaining the interval L of the abutting portion W1 as described above, and a function of restricting the position of the abutting portion W1 from shifting in the circumferential direction. The abutting portion W1 can be sent to an appropriate position with respect to the welding torch 1, and welding can be performed smoothly.
[0027]
As the workpiece W is fed and welding of the abutting portion W1 progresses, each insertion blade 21 is sequentially detached from the front end side of the abutting portion W1, and at a predetermined timing when welding of the abutting portion W1 proceeds to the rear end side. All the insertion blades 21 are detached from the rear end of the butting portion W1. The timing at which all the insertion blades 21 are separated from the butted portion W1 is properly maintained by the welded portion on the front end side where welding has been completed even if the interval L between the remaining butted portions W1 that have not been welded is not present. This is the time when the workpiece W has reached a position where it can be done, and it is not always necessary to hold the gap of the butted portion W1 by the insertion blade 21 until just before the welding of the butted portion W1 is completed.
[0028]
Thus, by performing MIG welding or MAG welding with the welding torch 1 in a state where the interval L of the abutting portion W1 of the workpiece W is maintained at an appropriate interval by the insertion blades 21, the abutting portion W1 has a seam formed by welding. A back beat W2 is also formed on the entire side surface.
[0029]
As described above, the work W is fed to the welding torch 1 through the guide member 4 while the gap holding means 2 holds the gap L of the abutting portion W1, and welding is performed as in the prior art. In addition, a cylindrical body excellent in strength can be easily formed, and a highly reliable cylindrical body can be provided even when high strength is required as the cylindrical body.
[0030]
In addition, although this Embodiment demonstrated as the space | interval holding | maintenance means 2, what hold | maintains the space | interval L of butt | matching part W1 by the front-end | tip part 22 of the said insertion blade 21 at an appropriate space | interval while circulatingly driving the some insertion blade 21. FIG. The means for holding the abutting portion W1 at an appropriate interval is not limited to the insertion blade 21, and any means can be used as long as it can hold the abutting portion W1 at an appropriate interval, such as a roller.
[0031]
Further, in the present embodiment, the welding is performed by placing the butted portion W1 on the top, and welding is performed by shifting the position of the butted portion W1 in the circumferential direction within a range that does not hinder the welding. You may go. In this case, it goes without saying that the insertion blade 21 and the welding torch 1 are arranged corresponding to the positions.
[0032]
Further, the cylindrical body is not limited to a circular shape as in the present embodiment, and may be an elliptical shape.
[0033]
【The invention's effect】
As described above, according to the cylindrical body welding method of the present invention, the workpiece is directed toward the welding torch through the insertion hole of the guide member in a state where the gap between the butted portions of the workpiece is held at a predetermined interval by the interval holding means. By feeding the above gap and MIG welding or MAG welding the above gap, the back beat can be formed entirely on the inner surface side of the seam formed by welding at the butt portion, thereby forming a cylindrical body with excellent strength. Even when high strength is required as the cylindrical body, a highly reliable cylindrical body can be provided.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of an apparatus for carrying out a cylindrical body welding method of the present invention.
FIG. 2 is a perspective view showing a shape of a workpiece.
FIG. 3 is a cross-sectional view showing a cross-sectional shape of each insertion blade.
FIG. 4 is a cross-sectional view showing a guide member.
FIG. 5 is a front view showing a welding state of a butted portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Welding torch 2 Space | interval holding means 21 Inserting blade 22 Tip part 4 Guide member

Claims (1)

A welding method in which a cylindrical body is formed by welding the butted portions of both end edges of a workpiece obtained by bending a plate body into a cylindrical shape in advance,
While having an insertion hole corresponding to the diameter of the workpiece, a guide member having a slit formed on the upper surface,
An interval holding means having a plurality of insertion blades arranged above the guide member and inserted through the slits into a gap between the butting portions of the workpiece and circulated in the feed direction of the workpiece;
By adjusting the insertion amount of the tip of the insertion blade to be inserted into the gap between the workpieces, the gap is maintained at a predetermined interval on the inner side surface of the workpiece so that the back beat is possible. In this state, the circulation speed of these insertion blades while the tuned with feed rate of the workpiece, the workpiece feed towards the welding torch through the insertion hole of the guide member, a method of welding cylinder, characterized by MIG welding or MAG welding the gap.

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