JP4299998B2 - Welding distortion remover for box-shaped long section welded structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding distortion removing method and a welding distortion removing apparatus after box assembly welding of a long welded structure such as a boom.
[0002]
[Prior art]
The telescopic boom used for a crane vehicle or an aerial work vehicle is configured such that an intermediate boom and a tip boom are sequentially inserted into a base end boom so as to be freely slidable. The booms at each stage form a box-shaped cross section by combining vertical plates with upper and lower plates, and are well known as box-shaped cross-section long welded structures. Therefore, the prior art will be described using a boom of a crane vehicle as an example.
[0003]
(A) and (b) of Drawing 8 are figures showing an example of boom 4 which performed box assembly welding.
[0004]
The boom 4 shown in (a) is a combination of the two vertical plates 1, the upper plate 2, and the lower plate 3 in the form of a cut plate, and welding is performed on the joint portion. Such welding is called fillet welding.
[0005]
In the boom 4 shown in FIG. 2B, two vertical plates 1 have a U-shaped cross section by bending the upper and lower ends thereof inward. After the upper plate 2 and the lower plate 3 are combined so as to overlap with the upper and lower flange portions 1a and 1b of the vertical plate 1, welding is performed on the joint portion. Such welding is called flare welding.
[0006]
FIG. 9 is a detailed view of portion B in FIG. 8 and shows details (hatched portion) of the weld bead at the joint. That is, (a) 5 is a fillet weld bead, and (b) 5 is a flare weld bead.
[0007]
FIG. 10 is a cross-sectional view taken along the line AA in FIG. 8 and shows an example of welding distortion generated in the vertical plate 1 by the above welding. In (a), wavy distortion occurs in the vertical plate, which is called buckling deformation. In (b), warpage (bending) occurs in the entire vertical plate. Such welding distortion is caused by the fact that when the weld bead 5 is cooled and solidified from the melted state immediately after welding, a tensile stress remains along the weld bead on the vertical plate 1 as a base material, and balances it with the outside. Compressive stress remains in the form. Therefore, it is considered that buckling deformation or warping (bending) occurs along the weld bead 5. The dimension H shown in the figure represents the height of the undulation of the buckling deformation, and is a measure of the magnitude of the welding distortion.
[0008]
A portion where the welding distortion of the vertical plate 1 of the boom 4 occurs is a portion where the slide plate comes into sliding contact when the telescopic boom is assembled. For this reason, the slide plate and the vertical plate 1 do not come into stable contact with each other during the boom expansion / contraction operation, causing vibration or abnormal noise. Further, the welding distortion of the vertical plate 1 is very detrimental to the appearance because the deformed state is well understood when viewed from the outside when the telescopic boom is extended.
[0009]
[Problems to be solved by the invention]
However, as a method for removing the distortion generated in the vertical plate of the box-shaped cross-section long welded structure such as the boom described above, a method in which an operator hits and corrects the corrugated portion of the vertical plate with a hammer, or a gas flame, etc. The method of heating with water and water cooling (local heating water cooling method) was taken. However, the welding distortion removal work with a hammer is a work that takes a long time in a loud sound by lifting a heavy hammer and is exactly 3k work (tight, dirty, dangerous work), and improvement is desired. It was. In addition, the local heating water cooling method relies heavily on the intuition and experience of the worker, and it was difficult to implement unless it was a skilled worker.
[0010]
Therefore, the present invention proposes a welding distortion removing device using roller rolling, and intends to improve the distortion removing work content of the welding distortion generated in the box-shaped long section welded structure such as the boom described above. .
[0011]
[Means for Solving the Problems]
A welding distortion removing device for a box-shaped cross-section long welded structure according to claim 1 of the present application is a box-assembled welding of a long welded structure that forms a box-shaped cross section by combining two vertical plates on the upper and lower plates. This is a subsequent strain relief device, in which a long welded structure after box assembly welding is placed, and a slide base that is slidable in the longitudinal direction of the long welded structure on the base, and the slide base is slid A slide base driving means for driving, and four inner rollers arranged in a pair on the left and right , respectively , are rotatably provided, and an inner roller core disposed on the slide stroke of the slide base, and a longitudinal welding structure Inner roller pressing means disposed in the inner roller core to press the inner roller against the plate from the inside of the long welded structure, and the inner roller core held in place with respect to the base and the core holding means for a pair disposed on the left and right respectively Provided rotatably four outer rollers, an outer roller holding means for holding the outer roller at a position corresponding to the core for the inner roller A on the slide base for sliding stroke, long welded structures An outer roller pressing means disposed on the outer roller holding means so as to press the outer roller against the vertical plate from the outside of the long welded structure, and the long welding after box assembly welding to the slide table A structure is placed, the vertical plate in the vicinity of the weld bead is sandwiched between the inner roller and the outer roller, and is pressed by the inner roller pressing means and the outer roller pressing means. Rolling is performed on the vertical plate in the vicinity of the weld bead along the weld bead of the long welded structure by sliding.
[0014]
The welding distortion removing device for the box-shaped cross-section long welded structure is a state in which the vertical plate in the vicinity of the weld bead is sandwiched between the inner roller and the outer roller, and is pressed by the inner roller pressing means and the outer roller pressing means. Rolling is performed by sliding the slide table with a slide table driving means, so that the portion of the vertical plate where welding distortion occurs can be uniformly rolled along the weld bead to reduce the internal residual stress. Therefore, it is possible to take out the welding distortion generated by the residual stress.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an entire welding distortion removing device 10 for a box-shaped cross-section long welded structure according to an embodiment of the present invention. In the description of the present embodiment, an example in which the welding distortion removing device 10 is applied to a boom 4 such as a crane car as a box-shaped cross-section long welded structure will be given.
[0016]
Reference numeral 11 denotes a slide base on which the boom 4 after box assembly welding is placed and which can slide on the base 13 in the boom longitudinal direction. The slide table 11 can slide on the upper surface of the base 13 over almost the entire length of the long base 13 installed in the factory.
[0017]
Reference numeral 12 denotes slide table driving means for slidingly driving the slide table 11. The slide table driving means 12 of this embodiment employs chain drive. The chain 18 is hung on a sprocket 17a that is rotatably provided on the left side end 13a of the base and a sprocket 17b that is rotatably provided on the central part 13b of the base, and a part of the chain 18 is connected to the end 11a of the slide base. ing. The sprocket 17b of the base central portion 13b is rotationally driven by an electric motor and a speed reducer (not shown). Therefore, the slide table 11 can be slid by driving the chain 18 with the electric motor.
[0018]
Reference numeral 14 denotes an inner roller core that is rotatably provided with an inner roller and is disposed at the base central portion 13 b on the slide stroke of the slide table 11. A core holding means 15 holds the inner roller core 14 at a predetermined position with respect to the base 13. Specifically, the core holding means 15 is a long rod-like member such as a pipe, one end of which is connected and fixed to the base left end 13a, and the other end to the inner roller core 14. It is connected and fixed.
[0019]
Reference numeral 16 denotes an outer roller holding means that rotatably includes an outer roller and holds the outer roller at a position on the slide stroke of the slide base 11 and corresponding to the inner roller core 14. In FIG. 1, the outer roller holding means 16 is shown with the inner side roller core 14 disposed on the inner side thereof omitted in order to show the inner roller core 14.
[0020]
FIG. 2 is a detailed view of a C portion in FIG. 1 and shows details of a central portion of the boom welding distortion removing device 10. The entire slide base 11 is located on the right side of the base 13, and the position of the slide base 11 is a position when the boom 4 for removing the welding distortion is placed on or lowered from the slide base 11. .
[0021]
In the state of the slide table 11, the inner roller core 14 is placed on the slide table end portion 11a. From this state, when the slide base 11 and the boom 4 are slid and driven to the left side of the drawing by the slide base drive means 12, the inner roller core 14 and the core holding means 15 enter the inside of the boom 4, and the boom 4 is moved to the left end of the base. It will slide toward the part 13a.
[0022]
FIG. 3 is a detailed view of the inner roller core 14. The inner roller core 14 includes a core body 20, core support portions 21 and 22, and a connecting portion 23. The core body 20 has inner rollers 24 and 25 arranged at the center thereof so as to be rotatable up and down.
[0023]
4 is a detailed sectional view taken along the line DD of FIG. A pair of inner rollers 24 and 25 are arranged on the left and right, respectively, and the four inner rollers 24a, 24b, 25a and 25b are aligned with the vertical plate at the same time along the weld beads at the four corners of the box-shaped section of the boom. Roller rolling can be performed.
[0024]
The shaft portion 26 of the upper right inner roller 24 a shown in FIG. 4 is rotatably supported by a roller support portion 27 via a slide bearing 28. Further, the roller support portion 27 is configured to project laterally with respect to the core body 20. Further, the inner roller 24a can be further pressed against the vertical plate by the inner roller pressing means (not shown) in contact with the boom vertical plate. The pressurizing mechanism of the inner roller pressurizing means is composed of a hydraulic cylinder and a link, and the expansion / contraction operation of the hydraulic cylinder is transmitted to the roller support portion 27 via the link so that the inner roller 24a is pressed against the vertical plate. It has become. The other inner rollers 24b, 25a and 25b have the same configuration as the upper right inner roller 24a.
[0025]
The core support portions 21 and 22 shown in FIG. 3 are arranged in the longitudinal direction of the core body 20 and are integrally formed with the core body 20 so as to support the core body 20. Yes. The core support portions 21 and 22 have rotatable wheels 29. As the slide table 11 slides, the wheels 29 roll on the upper surface of the slide table 11 and the upper surface of the lower plate 3 of the boom. The core body 20 is supported.
[0026]
The inner roller core 14 can be disconnected by inserting and removing the connecting pin 30 through the core holding means 15 and the connecting portion 23. The core holding means 15 is constituted by a long pipe, and an oil feeding means 31 such as a hydraulic hose is disposed in the core holding means 15 so as to supply pressure oil to the hydraulic cylinder of the inner roller pressurizing means. ing.
[0027]
A plurality of inner roller cores 14 described above having different arrangement dimensions of the inner rollers 24a, 24b, 25a, and 25b in accordance with the boom cross-sectional dimensions for which welding distortion is to be removed are prepared. Then, the inner roller core suitable for the boom cross-sectional dimension to be subjected to boom welding distortion removal is selected and connected to the core holding means 15 at the connecting portion 23 for use.
[0028]
FIG. 5 is a detailed view taken along the line EE in FIG. 2 and shows the outer roller holding means 16 for holding the outer roller. Reference numerals 41a, 41b, 42a, 42b denote outer rollers held at positions corresponding to the inner rollers 24a, 24b, 25a, 25b of the inner roller core 14 shown in FIG. The upper right outer roller 41 a is rotatably supported by a roller support 43, and the roller support 43 is supported by an outer roller pressing means 44. Further, the outer roller pressing means 44 is constituted by a hydraulic cylinder, and the outer roller 41a held at the tip of the outer roller pressing means 44 can be moved in the horizontal direction toward the boom 4 placed at the center of the outer roller holding means 16. Thus, it is possible to further pressurize the outer roller 41a in a state where the outer roller 41a is in contact with the vertical plate 1 of the boom 4.
[0029]
The outer roller pressing means 44 is attached to the outer frame 45 so as to be movable in the vertical direction, and its vertical position can be adjusted by the vertical position adjusting cylinder 46 according to the cross-sectional dimension of the boom 4. . The other outer rollers 41b, 42a, 42b have the same configuration as the upper right outer roller 41a described above.
[0030]
Reference numerals 11, 12, 13 and 17b denote the slide table, slide table drive means, base and sprocket described above.
[0031]
Reference numeral 47 is a boom pressing means, and a rotatable pressing roller 48 disposed at the tip of the boom pressing means is configured to be movable up and down by a pressing cylinder 49, and the boom 4 is intended to float upward during the roller rolling operation. Can be pressed from above.
[0032]
The welding distortion removing operation after the boom box assembly of the boom 4 by the welding distortion removing apparatus 10 having the above-described configuration is as follows.
[0033]
As shown in FIG. 1, a boom 4 that has undergone boom box assembly welding that forms a box-shaped cross section in which vertical plates are combined with upper and lower plates is placed on a slide base 11 of a welding distortion removing device 10. Further, the boom 4 is fixed to the slide table 11 by fixing means that can be fixed and released provided on the slide table 11 (not shown).
[0034]
At this time, as shown in FIG. 5, the inner rollers 24 a and the outer rollers 41 a are waiting at a position away from the boom vertical plate 1.
[0035]
Next, the entire slide 4 is moved from the state shown in FIG. 1 to the predetermined roller rolling start position on the left side of the welding distortion removing device 10 by the slide table driving means 12. Roller rolling, which will be described later, is performed in the return slide stroke of the slide table 11. At this time, the inner roller core 14 is located inside the boom 4 and in the vicinity of the right end of the boom 4.
[0036]
In the assembly process of the boom 4, at the stage of welding distortion removal after box assembly welding, no other parts are attached to the end of the boom 4, and the inner roller core 14 described above is easily mounted on the boom 4. 4 can be entered.
[0037]
Here, the inner roller 24a... And the outer roller 41a... Are brought into contact with the vertical plate 4 by the inner roller pressing means and the outer roller pressing means 44. Further, the inner roller 24a. Pressurization is performed until the generated stress reaches a rolling stress that exceeds the yield point of the vertical plate 1. FIG. 6 shows the relationship among the upper right inner roller 24a, outer roller 41a, and boom 4 at this time. The position where the inner roller 24a and the outer roller 41a sandwich the vertical plate 1 is in the vicinity of the weld bead 5 where the vertical plate 1 is welded to the upper plate 2, and is a position slightly separated downward.
[0038]
The roller rolling conditions such as the diameter, width, pressure, and distance from the weld bead 5 of the inner roller 24a and the outer roller 41a are the materials and dimensions of the boom upper and lower plates and the vertical plate, welding conditions, and the like. Considering this, experimentally select a value that optimizes welding distortion removal.
[0039]
In this state, the boom 4 is slide-driven while being rolled by the slide table driving means 12 toward the right. The vertical plate 1 is strongly sandwiched between the inner rollers 24a... And the outer rollers 41a... So that a large force is required for the slide drive, but the slide table drive means 12 is designed to have a sufficient drive force. Has been.
[0040]
After performing roller rolling on the necessary part of the boom 4 over almost the entire length, the slide drive of the slide base 11 is stopped. Here, the pressing of the inner roller 24a... And the outer roller 41a... To the vertical plate 1 by the inner roller pressing means and the outer roller pressing means 44 is stopped, and the inner rollers 24a. The outer rollers 41a... Are moved away from the vertical plate 1.
[0041]
Further, the slide base 11 is moved rightward in the drawing of FIG. 1 so that the inner roller core 14 is completely pulled out from the left end portion of the boom 4. The fixing of the boom 4 by the fixing means provided on the slide table 11 is released, and the boom 4 is moved from the slide table 11 to the next work process. The above is the content of the distortion removal operation of the weld distortion of the boom 4 by the welding distortion removal apparatus 10.
[0042]
FIG. 7 is a graph showing an example of the effect of the distortion removing device. The horizontal scale of the graph represents the position in the longitudinal direction of the boom, and the vertical scale represents the dimension of the distortion amount H of the vertical plate. The broken line on the graph represents the shape of the vertical plate after welding, and the solid line represents the shape of the vertical plate after the distortion removal work.
[0043]
The conditions on the boom side at the time of confirming the effect are as follows: the material of the boom vertical plate is HT590, the plate pressure is t3.2, the welding heat input is 7382 J / cm, and the conditions of the strain relief device are the rolling force of 11000 kg and the roller rolling width of 25 mm. It is.
[0044]
As shown in the graph of FIG. 7, the average strain amount H = 8.0 mm after welding is reduced to the average strain amount H = 1.2 mm after the strain removing operation by the welding strain removing device of the present application. I understand. This indicates that the average distortion amount H has decreased by 85%.
[0045]
Further, it has been confirmed that even if the welding distortion removal is performed by the welding distortion removing apparatus of the present application, the plate pressure reduction and work hardening of the roller rolling portion are very small, and the appearance of the rolling traces is not a problem.
[0046]
【The invention's effect】
Since it is constituted and operates as described above, according to the welding distortion removing device for a box-shaped cross-section long welded structure described in claim 1 of the present application, the vertical plate in the vicinity of the weld bead is made to have an inner roller and an outer roller. Since the roller rolling is performed by sliding the slide table with the slide table drive means while being pressed by the inner roller pressure means and the outer roller pressure means, the portion where the vertical plate welding distortion has occurred Can be uniformly rolled along the weld bead to reduce the internal residual stress, and the welding distortion generated by the residual stress can be removed.
[0048]
Therefore, it is possible to reduce the work that the conventional worker has corrected by smashing all the parts where the weld distortion of the box-shaped cross-section long welded structure with a hammer, and skill like the local heating water cooling method can be reduced. Since it is possible to perform welding distortion removal work without necessity, the work content can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an entire welding distortion removing device for a long welded structure according to an embodiment of the present invention.
FIG. 2 is a detailed view of a part C in FIG. 1;
FIG. 3 is a detailed view of an inner roller core.
4 is a detailed DD cross section of FIG. 3;
FIG. 5 is a detailed view taken along the line EE in FIG. 2;
FIG. 6 is a diagram illustrating a relationship among an inner roller a, an outer roller, and a boom during roller rolling.
7 is a graph showing the effect of the distortion removing device of the present application. FIG. 8 is a diagram showing an example of a boom subjected to box assembly welding.
9 is a detailed view of part B in FIG. 8. FIG.
10 is a cross-sectional view taken along the line AA in FIG.
[Explanation of symbols]
1 is a vertical plate, 2 is an upper plate, 3 is a lower plate, 4 is a boom, 5 is a weld bead, 10 is a welding strain relief device, 11 is a slide base, 12 is a slide base drive means, 13 is a base, and 14 is Inner roller core, 15 is core holding means, 16 is outer roller holding means, 24a, 24b, 25a and 25b are inner rollers, 41a, 41b, 42a and 42b are outer rollers, and 44 is outer roller pressure means.

Claims (1)

A strain relief device after box assembly welding of a long welded structure in which two vertical plates are combined with upper and lower plates to form a box-shaped cross section,
A slide base that mounts a long welded structure after box assembly welding and is slidable in the longitudinal direction of the long welded structure on the base,
Slide base driving means for slidingly driving the slide base;
Four inner rollers each arranged in a pair on the left and right are rotatably provided, and an inner roller core disposed on the slide stroke of the slide table,
Inner roller pressing means disposed on the inner roller core so as to press the inner roller against the longitudinal plate of the long welded structure from the inside of the long welded structure;
Core holding means for holding the inner roller core in a predetermined position with respect to the base;
Outer roller holding means that rotatably includes four outer rollers arranged in pairs on the left and right sides, and holds the outer rollers at positions corresponding to the inner roller core on the slide stroke of the slide table,
An outer roller pressing means disposed on the outer roller holding means so as to press the outer roller against the longitudinal plate of the long welded structure from the outside of the long welded structure,
A long welded structure after box assembly welding is placed on the slide table, a vertical plate near the weld bead is sandwiched between the inner roller and the outer roller, and pressed by the inner roller pressing means and the outer roller pressing means. In this state, the slide table is slid by a slide table driving means, and a roller rolling is performed on a vertical plate in the vicinity of the weld bead along the weld bead of the long welded structure. Weld distortion remover for long welded structures.

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