JP2003334693A - Method and apparatus for welding round tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the different levels of butted pars of left and right edges of a work without deteriorating the workability of taking out a work set before welding or a product after welding. <P>SOLUTION: A method for welding a short tube comprises the steps of: interposing semi-clamp operating means 60 between a rocking arm 13 and a cylinder 14 in the left side upper clamp 10 of upper clamps 10, 20 for positioning and fixing the left and right edges of the work 1 molded in a cylindrical shape; positioning fixedly the right side edge of the work 1 by the clamp 20, bringing a caul 68 under the arm 13 into contact with a stopper 67 by the operation of a cylinder 62 in the means 60; positioning a movable member 12 at a half- opening position; advancing a retaining block 31 of the left side of the clamp 30 in the state that the left side edge is suitably retained; butting the left and right edges of the work 1 so as not to bring about large different levels; thereafter positioning fixedly the left side edge by the member 12, and welding the butted pars of the left and right edges. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short pipe welding method and a short pipe welding apparatus for producing a pipe having a predetermined length.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, a short pipe welding apparatus of this type has a cylindrical shape and has a fixed length (for example,
200-400 mm) work 1 left and right edge portion 2,
Two upper clamp units (hereinafter, simply referred to as upper clamps) 10 and 20 for positioning and fixing 3 and a side clamp unit (hereinafter, simply referred to as side clamp) 30 for positioning and fixing the work 1 from the side,
A welding unit (not shown) for welding the abutting portions of the left and right edge portions 2 and 3 is provided. The upper clamps 10 and 20 are fixed members 11 and 21 that fix the edge portions 2 and 3 of the work 1 from the inside and the fixing members 1 and 21.
1, 21 are provided with movable members 12 and 22 that move forward and backward obliquely from above by a driving means (not shown), while the side clamps 30 are a pair of pressing blocks that are linearly moved independently by the driving means. 31 and 32 are provided.

At the time of pipe manufacturing, each upper clamp 10,
After setting the work 1 in the apparatus with the movable members 12 and 22 of 20 and the pair of pressing blocks 31 and 32 of the side clamp 30 positioned at the unclamp ends, that is, the fully opened state, first, the side clamp 30 The presser blocks 31 and 32 are moved forward (clamping operation) to move the left and right edge portions 2 and 3 of the work 1 to the reference pin 40.
Then, the movable member 22 of one (here, the right side) upper clamp 20 is moved to the fixed member 21 side, and as shown in FIG.
Is positioned and fixed, and when the fixing is completed, the holding block 31 on the left side of the side clamp 30 is retracted to the unclamp end.

After that, first, the reference pin 40 is pulled out,
Next, the pressing block 31 on the left side of the side clamp 30 is clamped again, and as shown in FIG. 9, the left edge portion 2 of the work 1 is abutted against the right edge portion 3 which has been prepositioned and fixed, and then, The movable member 12 of the left upper clamp 10 is moved to the fixed member 11 side to move the work 1
Position and fix the edge part 2 on the left side of the
Welding (usually TIG welding) is performed along the abutting portion of the left and right edge portions 2 and 3 of.

[0005]

However, according to the above-described conventional short pipe welding apparatus and method, when the left and right edge portions 2 and 3 of the work 1 are abutted with each other by the side clamp 30, the right edge portion of the work 1 is abutted. While the left edge portion 2 is a free end portion while the third edge portion 3 is positioned and fixed, the left edge portion 2 is abutted against the right edge portion 3 without a step. If this step difference is large, even if the left upper clamp 10 is finally actuated, due to the frictional resistance of the abutting end faces of the left and right edge portions 2 and 3, as shown in FIG.・ Right edge part 2
There is a problem in that the step 5 remains at the abutting portion between Nos. 3 and 3, not only the dimensional accuracy of the obtained short pipe deteriorates but also the welding strength decreases. Also, due to the influence of springback when molding the work 1, the left and right edge portions 2 and 3 are formed.
If the gap between the edge edges 2 and 3 of the workpiece 1 is abutted by the side clamp 30, the edge portions 2 and 3 will be in a so-called blanking state. As shown in FIG. 10, the overlapping portion 6 is formed between the left and right edge portions 2 and 3, and there is a problem that a separate and troublesome work for correcting the work 1 is required. The above-mentioned problem can be solved by setting the opening amount at the unclamping end of the left upper clamp 10 to a small value. However, when the opening amount is simply decreased, the work 1 is not put into the apparatus before welding. A new problem arises that it is troublesome to take out the short pipe (product) from the device after setting or welding.

The present invention has been made in view of the above-mentioned problems of the prior art. The problem is that the workability of the work set before welding and the product removal after welding is not deteriorated. An object of the present invention is to provide a short pipe welding method and apparatus capable of reducing the step difference between the abutting portions of the left and right edge portions and stably and efficiently producing a short pipe excellent in dimensional accuracy and strength. .

[0007]

In order to solve the above problems, in the short pipe welding method according to the present invention, one of the left and right edge portions of a cylindrically shaped work is positioned and fixed by a first upper clamp unit. After that, the side clamp unit is clamped to bring the other edge portion into contact with the one edge portion, and then the second upper clamp unit positions and fixes the other edge portion to the left
In a short pipe welding method for welding a butt portion of a right edge portion, prior to a clamping operation of the side clamp unit, the second upper clamp unit is stopped at a semi-open position between an unclamp end and a clamp end. It is characterized by Further, a short pipe welding apparatus according to the present invention for solving the above-mentioned problems is provided with the above-described two upper clamp units, a side clamp unit and a welding unit, and one of the upper clamp units is provided. A half clamp operating means for performing a clamp operation of the one upper clamp unit is provided at a half open position between the unclamp end and the clamp end. In the short pipe welding method and apparatus configured as described above,
By appropriately setting the semi-open position of the second upper clamp unit, it is possible to suppress the step difference between the one edge portion that is preliminarily positioned and fixed to the other edge portion within a certain range. When the clamp operation is performed, a large step difference does not occur at the abutting portion of the left and right edge portions of the work. Moreover, since the second upper clamp unit does not have any inconvenience in pipe manufacturing even if its unclamp end is arbitrarily set,
It is possible to secure a sufficient unclamp end opening amount that does not hinder the work set and product removal. In the device of the present invention, it is desirable that the half-clamp actuating means has a configuration in which the half-open position can be arbitrarily changed,
As a result, the optimum semi-open position can be set according to changes in the material of the work and the plate thickness. In the device of the present invention, the upper clamp unit includes a fixed member that is fixed in position, a movable member that is supported by a swing arm,
A drive means for moving the movable member forward and backward with respect to the fixed member via the swing arm may be provided. In this case, the half-clamp actuating means may include the swing arm and the swing arm. The intermediate position can be easily set in the upper clamp unit by interposing it with the driving means.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 and FIG. 2 show a short pipe welding apparatus as one embodiment of the present invention. The short pipe welding apparatus includes two upper clamp units (upper clamps) 10 and 20 for positioning and fixing the left and right edge portions 2 and 3 of the work 1 and a side for positioning and fixing the work 1 from the side. Clamp unit (side clamp) 30 and left and right edge parts 2 of the work 1
Since the reference pin 40 for setting the butt position of No. 3 and the welding unit 45 are the main constituent elements, there is no difference from the conventional one. Therefore, the same parts as those shown in FIG. And

In the present embodiment, each of the fixing members 11 and 21 constituting the upper clamps 10 and 20 is formed by a pillar (not shown) standing on the base 50 and the base 50.
It is mounted and fixed on the upper surface of the gate-shaped frame 51 extending in the horizontal direction (the direction perpendicular to the paper surface in FIGS. 1 and 2) along the line.

Further, in the present embodiment, the movable members 12 and 22 constituting the upper clamps 10 and 20 are arranged on the base 50 between the left and right movable members 12 and 22 at predetermined intervals. The columns 52 and 53 are supported by swinging arms 13 and 23 that are swingably supported by horizontal shafts 54 and 55. Of these swinging arms, the swinging arm 13 of the left upper clamp 10 has an inverted L shape and is axially supported by the horizontal shaft 54 so that its long side portion 13a stands upright. The movable member 12 is attached to the tip of a short side portion 13b extending in the lateral direction. The lower end portion of the long side portion 13a of the swing arm 13 penetrates the base 50 and extends to the lower side thereof. At this lower end portion, a cylinder (drive unit) installed on the lower surface of the base 50 via a bracket 56 is used. Means 14) are operatively connected via a semi-clamp actuating means 60 which will be described later. The swing arm 13 is adapted to move the horizontal shaft 54 according to the expansion and contraction movement of the cylinder 14.
The movable member 12 on the left side moves forward and backward with respect to the corresponding fixed member 11 obliquely from above. Therefore, the fixed member 11 and the movable member 1
2, the swing arm 13 and the cylinder 14 are one upper clamp (second upper clamp unit) 10 for clamping and unclamping the left edge portion 2 of the work 1.
Are configured.

Swing arm 2 of the right upper clamp 20
Reference numeral 3 denotes a T-shape, which is axially supported by the horizontal shaft 55 via a vertical side portion 23a thereof in a balance type.
The movable member 22 is attached to one end of a lateral side portion 23b extending in the lateral direction. Side 2 of swing arm 23
The other end of 3b is largely extended to one end of the base 50, and a cylinder (driving means) 24 installed on the base 50 is directly operatively connected to the other end. The swing arm 23 swings around the horizontal shaft 55 as a fulcrum according to the expansion and contraction of the cylinder 24, so that the right movable member 22 moves forward and backward obliquely with respect to the corresponding fixed member 21. . Therefore, the fixed member 21, the movable member 22, the swing arm 23, and the cylinder 24 are attached to the work 1
The other one upper clamp (first upper clamp unit) 20 that clamps and unclamps the right edge portion 3 of the above is configured.

On the other hand, the pair of left and right pressing blocks 31 and 32 constituting the side clamp 30 are provided on the base 50 with a guide rail 57 extending in a direction orthogonal to the portal frame 51 and a slider member 58 interposed therebetween. And is slidably supported. Cylinders (driving means) 33, 34 are installed behind the pressing blocks 31, 32 on the base 50. Each presser block 3
1, 32 and the cylinders 33, 34 behind them are connected by connecting means 35, 36, and the pressing blocks 31, 32 move on the guide rail 55 in accordance with the expansion and contraction of the corresponding cylinders 33, 34. It will move in a straight line.

Further, as shown in FIG. 2, the reference pin 40 is slidably fitted in a hollow guide 59 embedded in the portal frame 51. The lower end of the reference pin 40 is engaged with a cam 42 attached to a rotary shaft 41 extending in the gate-shaped frame 51 in parallel with the support column that supports the gate-shaped frame 51. Cam 4
2 is adapted to rotate integrally with the rotary shaft 41 by an operating lever 43 attached to the extension end of the rotary shaft 41, and the reference pin 40 inside the hollow guide 59 in response to the rotation of the cam 42. Move up and down. The reference pin 40
Are plural in the longitudinal direction of the portal frame 51 (usually 2
Have been installed. Further, the welding unit 44 is provided with a torch 46 for TIG welding here. Torch 4
6 is transferred in the horizontal direction and the vertical direction along the portal frame 51 by a transfer means (not shown) installed on the base 50.

Therefore, the half clamp operating means 60
Is a cylinder (clamping cylinder) 62 coaxially connected to the cylinder (clamping cylinder) 14 in the upper clamp 10 via a support plate 61, a rod end of the cylinder 62, and the swing arm 13. A connecting member 63 for connecting the lower end of the support plate 61, a stopper 67 fixed to the tip of a support frame 64 extending from the support plate 61 in parallel with the rod of the cylinder 62 with a bolt 66 via a shim 65, and the stopper 67. The connecting member 6 so that it can come into contact with
3 and the backing plate 68 fixed to 3. The connecting member 63 is L-shaped, one end of which is rotatably attached to the rod end of the semi-clamping cylinder 62 using a pin 69, and the other end of which is the lower end of the swing arm 13. The portion is fixed by using a bolt 70.

In the half-clamp actuating means 60, the shortened end of the half-clamping cylinder 62 is in the original position. In this original position, a predetermined gap is formed between the stopper 67 and the contact plate 68. It has become. On the other hand, in the left upper clamp 10, the extension end of the clamp cylinder 14 is the clamp end, and the shortened end of the cylinder 14 is the unclamp end.
When the half-clamping cylinder 62 is extended at the shortened end, that is, the unclamping end, the swing arm 13 swings clockwise as seen in FIGS. 1 and 2, until the contact plate 68 contacts the stopper 67. This allows the movable member 12 to be positioned at the semi-open position between the clamp end and the unclamp end.

FIG. 3 shows the stop position of the movable member 12 in response to the expansion and contraction of the cylinders 14 and 62 described above. The movable member 12 at the extension end of the clamping cylinder 14 works with respect to the fixed member 11. 1 to the solid line position for pressing the left edge portion 2 (full open position), to the two-dot chain line position greatly separated from the fixing member 11 at the extended end of the cylinder 14, and to the solid line position when the half-clamping cylinder 62 is extended. Positioning is performed at the position of the alternate long and short dash line (half-open position) between the position of the alternate long and two short dashes line. In this case, the semi-open position (the position indicated by the chain double-dashed line) of the movable member 12 can be adjusted as appropriate by changing the thickness of the shim 65 interposed between the stopper 67 and the support frame 64.

Hereinafter, a short pipe welding method using the apparatus configured as described above will be described with reference to FIGS.
At the time of pipe making, first, as shown in FIG. 4, the workpiece 1 is fully opened with the movable members 12 and 22 of the upper clamps 10 and 20 and the pair of holding blocks 31 and 32 of the side clamp 30 being unclamped ends. Set in the device,
Next, as shown in the figure, the cylinders 33 and 34 of the side clamp 30 are extended so that the pair of pressing blocks 3
1, 32 are moved forward (clamping operation) to press the left and right edge portions 2 and 3 of the work 1 against the reference pin 40. The reference pin 40 has a right side surface 40 at the tip thereof.
a is the reference surface. Next, the clamping cylinder 24 of the upper clamp 20 on the right side is extended, and FIG.
The movable member 22 is moved to the fixed member 21 side to position and fix the edge portion 3 on the right side of the work piece 1 as shown in (3), and subsequently, the holding block 31 on the left side of the side clamp 30 is retracted to the unclamp end. By retreating the pressing block 31 to the unclamping end, the left edge portion 2 of the work 1 becomes free to move and returns to the original open position with respect to the right edge portion 3.

Next, the operation lever 43 of the reference pin 40 is
By rotating from the two-dot chain line position in FIG. 2 to the solid line position, the cam 42 pulls down the reference pin 40 and retracts the reference pin 40 from between the left and right edge portions 2 and 3 of the work 1 as shown in FIG. Let Then, in synchronization with the withdrawal of the reference pin 40, the half-clamping cylinder 6 in the half-clamp actuating means 60 attached to the upper clamp 10 on the left side.
2 is extended. Then, the swing arm 13 moves to the position shown in FIG.
2 and 2, it rotates clockwise, and the movable member 12 supported thereby moves (clamps) to the fixed member 11 side as shown in FIG. The rotation of the swing arm 13 is stopped by the contact plate 68 provided on the connecting member 63 at the lower end thereof contacting the stopper 67, and accordingly, the movable member 12 is clamped as shown in FIG. The movement is stopped at the half-open position (the position indicated by the alternate long and short dash line) between the end and the unclamp end, whereby the left edge portion 2 of the work 1 is slightly pressed by the movable member 12.

Next, as shown in FIG. 5, the holding block 31 on the left side of the side clamp 30 is attached to the corresponding cylinder 3.
It is advanced again by the extension operation of 3. Then work 1
The left edge portion 2 of the movable member 12 of the upper clamp 10 is
While sliding on the surface of, the surface moves to the right edge portion 3 side and is abutted to the edge portion 3. At this time, since the movable member 12 is positioned at the semi-open position by the half clamp actuating means 60 as described above, the left edge portion 2 does not cause blank driving, and does not cause a large step difference on the right side. Is abutted to the edge portion 3 of the.

Next, as shown in FIG. 6, the clamp cylinder 14 in the left upper clamp 10 is extended to move the movable member 12 through the swing arm 13 to the fixed member 1.
Then, the left edge portion 2 of the work 1 is positioned and fixed. At this time, as described above, since the left edge portion 2 is abutted against the right edge portion 3 without making a large step, the left edge portion 2 is smoothly displaced downward without receiving a large friction resistance, As a result, left
The right edge portions 2 and 3 have their upper surfaces substantially aligned with each other,
That is, they are abutted with almost no step. After that, the torch 46 of the welding unit 45 is carried in to the starting end of the abutting portion of the left and right edge portions 2 and 3 by a transfer means (not shown), and then the abutting portion of the torch 46 while blasting an arc with the work 1. The butt portions of the left and right edges are arc-welded (here, TIG welding) over their entire length. Since the left and right edge portions 2 and 3 are abutted with each other with almost no step as described above, the short pipe P (FIG. 6) having excellent dimensional accuracy and strength can be obtained. Like

After completion of the short pipe P, the movable members 12 and 22 in the upper clamps 10 and 20 and the pair of pressing blocks 31 and 32 in the side clamps 30 are unclamped ends, that is, as shown in FIG. It is returned to the fully open state. At this time, in the left upper clamp 10, the clamping cylinder 14 and the semi-clamping cylinder 62 are simultaneously actuated to the shortened ends, whereby the movable member 12 in the upper clamp 10 is also fully opened, and therefore the short clamp is shortened. Tube P
Can be smoothly taken out from the inside of the device. Here, when the material and plate thickness of the work 1 are changed, a slight difference occurs in the amount of step difference between the left and right edge portions 2 and 3 due to the final butt (FIG. 5). In this case, If necessary, the shim 65 (FIG. 2) is replaced with one having an appropriate plate thickness to change the half-open position of the upper clamp 10.

It should be noted that the reference pin 40 is not pulled down vertically as in the above-described embodiment, but as shown in FIG.
The reference pin 40 may be smoothly retracted without being subjected to the frictional resistance of the right edge portion 3 in this case.
In this way, to pull down the reference pin 40 diagonally downward,
The hollow guide 59 (FIG. 2) in the above-described embodiment may be arranged in an inclined manner and the tip end portion of the reference pin 40 may be bent so as to be upright.

Although the TIG welding torch 46 is used as the welding unit 45 in the above-described embodiment, the present invention is not limited to this welding unit and method, and plasma welding, other than TIG welding, may be used. Laser welding,
Various welding methods such as electron beam welding can be used.

[0024]

As described above, according to the short pipe welding method and apparatus of the present invention, the workability before welding and the workability of taking out products after welding are not deteriorated.
Since the step difference between the abutting parts of the left and right edge parts of the work can be greatly reduced, there is an effect that a short tube excellent not only in dimensional accuracy but also in strength can be stably and efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a side view showing an overall structure of a short pipe welding apparatus according to the present invention.

FIG. 2 is a side view showing a main part structure of the present short pipe welding apparatus.

FIG. 3 is a schematic diagram showing an operating state of a movable member that constitutes an upper clamp unit in the present short pipe welding apparatus.

FIG. 4 is a schematic view showing the initial implementation status of the short pipe welding method according to the present invention step by step.

FIG. 5 is a schematic view showing the medium-term implementation status of the short pipe welding method according to the present invention step by step.

FIG. 6 is a schematic view showing in sequence the final stage implementation status of the short pipe welding method according to the present invention.

FIG. 7 is a schematic diagram showing a modified structure of a reference pin 40 used in the present short pipe welding apparatus.

FIG. 8 is a schematic view showing a basic structure of a conventional short pipe welding apparatus and a state of implementation of welding by the apparatus.

FIG. 9 is a schematic view showing a defect occurrence state in the conventional short pipe welding method.

FIG. 10 is a schematic view showing another problem occurrence state in the conventional short pipe welding method.

[Explanation of symbols]

1 Work 2, 3 Edge 10 Left Upper Clamp (Second Upper Clamp Unit) 11,21 Fixed Member 12,22 Movable Member 13,23 Swing Arm 14,24 Clamp Cylinder 20 Right Upper Clamp (First Upper Clamp Unit) ) 30 side clamp (side clamp unit) 31, 32 presser block 40 reference pin 45 welding unit 46 torch 50 base 51 gate frame 60 half clamp actuating means 62 half clamp cylinder

Claims (4)

[Claims] 1. After positioning and fixing one of the left and right edge parts of a cylindrically shaped work by a first upper clamp unit, the side clamp unit is operated to clamp and the other edge part is fixed to the one edge part. Butt, and then, in the short pipe welding method of positioning and fixing the other of the edge parts by the second upper clamp unit and welding the abutting parts of the left and right edge parts, prior to the clamping operation of the side clamp unit. A short pipe welding method, characterized in that the second upper clamp unit is stopped at a semi-open position between an unclamp end and a clamp end. 2. An upper clamp unit of two machines for positioning and fixing left and right edge portions of a cylindrically shaped work, a side clamp unit for laterally positioning and fixing the work, the upper clamp unit and the side. In a short pipe welding device comprising a welding unit for welding the abutting portions of the left and right edge portions of the work, which are abutted by cooperation with a clamp unit, an unclamp is provided on one of the upper clamp units of the two machines. A short pipe welding device, characterized in that a half clamp operating means for performing a clamp operation of the one upper clamp unit is provided at a half open position between an end and a clamp end. 3. The short pipe welding apparatus according to claim 2, wherein the half clamp actuating means is capable of arbitrarily changing the half open position. 4. An upper clamp unit, a fixed member for fixing a position, a movable member supported by a swing arm, and a drive means for moving the movable member forward and backward with respect to the fixed member via the swing arm. The short pipe welding device according to claim 2 or 3, further comprising: a semi-clamp actuating means interposed between the swing arm and the driving means.