JPH06320267A - Welding equipment for spiral rib on inner surface of steel pipe - Google Patents

Abstract

PURPOSE:To perform satisfactory automatic welding by surely following up the shape of a rib material. CONSTITUTION:A welding equipment is constituted of steel pipe holding mechanisms 25, 26 and 28 rotating a steel pipe 1 in which a rib material 2 formed in a spiral shape, is inserted, while holding the steel pipe 1 in the horizontal direction, a tracing welding mechanism 11 installed at the tip of an arm 23 extending in the horizontal direction from a support 22 through a slide mechanism 32 in the longitudinal direction, and feeding mechanisms 24, 27 and 29 moving either of this tracing welding mechanism or the steep pipe holding mechanism in the longitudinal direction of the steel pipe. The tracing welding mechanism 11 consists of guide rolls 3a, 3b and 3c of one set three bases, holding down the upper surface and both side surfaces of the rib material 2, and a welding torch 10 combined as one body with those guide rolls.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a rotary penetration steel pipe pile,
The present invention relates to a steel pipe inner surface spiral rib welding device for attaching a spiral rib to a steel tube inner surface by welding.

[0002]

BACKGROUND OF THE INVENTION The present applicant has previously developed a rotary penetration steel pipe pile in which spiral ribs are attached to the inner and outer surfaces of the steel pipe by welding, and is disclosed in Japanese Patent Laid-Open No. 1-94112 and others. In these rotary penetration steel pipe piles, the spiral ribs on the inner surface of the steel pipe do not have to be provided over the entire length of the steel pipe, but it is necessary to attach the ribs over a specific range from the end, for example, about twice the diameter. Although the mounting dimensions of the ribs are not required to be as accurate as those of mechanical parts, it is desirable that the entire rib material be securely welded.

Such a rotary penetration steel pipe pile can be manufactured by various methods, but the spiral rib on the inner surface is attached by welding by forming a rib material of a steel wire having a diameter of about 13 mm in a spiral shape in advance. A method of flare-welding the rib material and the inner surface of the steel pipe by inserting the steel pipe into the steel pipe and moving the welding torch relatively in the length direction of the steel pipe while rotating the steel pipe is performed.

[0004]

By the way, the rib material is
For example, use a steel wire with a diameter of about 13 mm that is preformed into a spiral shape with an envelope diameter (outer diameter after forming) that is about 2 to 15 mm smaller than the inner diameter of the steel pipe, and a pitch that is about 10 to 20 mm larger than the specified pitch. However, the molding accuracy at this stage is about ± 2 mm in envelope diameter and ± 20 mm in spiral pitch. The pitch changes further when the preformed rib material is inserted into the steel pipe.

When welding is started, the rib material is displaced in the axial direction like a spring. Therefore, it is necessary for the welding torch to follow this movement. It is out of the welding point and is not practical.
In addition, it is difficult to install a monitor device such as an ITV inside the pipe in terms of dimensions, and the visibility is poor due to welding fumes and the like.

An object of the present invention is to solve the above problems and to realize a welding device capable of reliably following the shape of the rib material and performing good automatic welding.

[0007]

A steel pipe inner surface spiral rib welding apparatus according to the present invention comprises a steel pipe holding mechanism for rotating a steel pipe while holding it horizontally, and a lengthwise direction at the tip of an arm extending horizontally from a column. A spiral rib on the inner surface of a steel pipe, characterized in that it comprises a profile welding mechanism attached via a slide mechanism and a feed mechanism for relatively moving either the profile welding mechanism or the steel pipe holding mechanism in the length direction of the steel pipe. It is a welding device, and the copy welding mechanism has one set of rolls that press the spiral rib material inserted into the inner surface of the steel pipe from the top surface and two rolls that support both side surfaces with a predetermined spiral angle. It is composed of a copying portion formed of a guide roll and a welding torch integrally connected to the copying portion.

[0008]

[Operation] Welding deformation of rib material includes lifting in the rib axial direction and angular deformation with respect to the axial center. Which of these deformations is the main factor in determining whether a gap is formed between the rib material and the steel pipe surface? by. Welding speed of linear round bar (steel wire) on flat plate 50
According to the experimental results of welding at cm / min, lift-up deformation started to occur at the same time as welding was started, and the gap reached 3 mm at 150 to 200 mm from the starting point, making welding impossible. On the other hand, the amount of angular deformation was 15 to 30 ° per 1 m of welding length. Therefore, a downward force is applied to the ribs from the upper roll to prevent the floating deformation, and the angular deformation is utilized in the direction of decreasing the pitch.

When welding the rib on the inner surface of the steel pipe, when the rib material formed in a spiral shape is inserted into the steel pipe, the pitch of the rib material is locally changed by about ± 30 mm due to contact with the surface of the steel pipe, and the rib material is mounted on the inner surface of the steel pipe. When welding is performed, the pitch changes again. When the rib positions before and after welding were measured, as shown in FIG. 7, the part that contracted compared to the original pitch at the time of insertion was expanded by welding, and conversely the part expanded at the time of insertion was contracted by welding. Was confirmed. This means that the rib material is displaced in the axial direction like a coil spring by welding, and in order not to restrain this displacement, the rib material forming dimension should be 2 to more than the inner diameter of the steel pipe.
It is necessary to make the envelope diameter as small as 15 mm.

On the other hand, it is most realistic for the welding torch to follow the rib material itself, but in order for the welding torch to follow such displacement, it is necessary to provide the supporting portion with a structure capable of absorbing the displacement. Therefore, in the present invention, by providing a welding device via a slide mechanism that can move in the length direction of the steel pipe, providing a predetermined spiral angle to the guide roll, and pressing down only one place To solve this problem. That is, the steel pipe holding mechanism and the feeding mechanism of the present invention relatively move either the welding machine or the steel pipe by one pitch in the length direction of the steel pipe while the steel pipe makes one revolution, but the pitch of the rib material is as described above. Since there is a variation of about ± 30 mm, a slide mechanism is provided at the welding torch attachment part at the end of the arm to accommodate this variation, and the welding torch follows the rib material itself by a copying mechanism.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. Fig. 1 is an overall front view of the welding device, 20 is a base, 21 is a rail provided on the base, and 22 is a base 20.
A column is erected at one end of the column, and 23 is an arm extending horizontally from above the column. 24 is a traveling carriage that travels on the rail 21, 25 is a chuck that holds the steel pipe 1 on the traveling carriage, 26 is a rotating mechanism that rotates this chuck, 27 is a rail that is connected to the traveling carriage 24 by a connecting rod 29. A follower vehicle traveling on 21 is provided with a turning roller 28 for supporting the rotating steel pipe 1 above the follower vehicle 27. In the present embodiment, the steel pipe 1 held horizontally by the traveling carriage 24 and the follower carriage 27 advances by one pitch during one rotation. That is, the traveling carriage 24, the follower carriage 27, and the devices mounted on them constitute a steel pipe holding mechanism and a feeding mechanism.

FIG. 2 is a detailed view of a portion where the arm 23 and the steel pipe 1 are joined together. The copying welding device 11 attached to the end of the arm 23 welds the rib material 2 in the steel pipe 1 that rotates and advances. Shows. FIG. 3 is a detailed view of a part of the arm near the tip in the vertical direction from above. A fixed hardware 30 is attached to the tip of the arm 23, and a movable hardware 31 is fitted to this via a slide mechanism 32. A copying welding device 11 including a copying mechanism, a welding torch, etc. is attached to this movable metal object, and the entire copying welding device 11 has an angle θ around the vertical axis in accordance with the spiral angle (lead angle) θ of the rib material 2.
It is installed diagonally only. As shown in FIG. 4, which is a cross section taken along the line AA in FIG. 3, the slide mechanism 32 has a structure in which it can slide freely in the axial direction by means of a sliding groove.

FIG. 5 is a side view of the vicinity of the tip of the arm as seen from the front in the horizontal direction, and FIG. 6 is a copying welding device as viewed from the BB of FIG.
It is a partial front view of only 11 viewed from the front. The copying mechanism of this copying welding device 11 is composed of one set of three guide rolls 3a, 3b,
Composed of 3c. Horizontal roll as shown in Figure 3
3a and 3b sandwich the rib material 2 from both left and right sides, and use the welding torch 10
The rib material 2 is made to follow the directional position of. As described above, the position of the welding device 11 in the longitudinal direction is free from the arm 23 side because the slide mechanism 32 is interposed, and is determined by the guide rolls 3a and 3b. Further, as shown in FIGS. 5 and 6, the vertical roll 3c not only causes the height of the welding torch 10 to follow the rib material 2, but also the arm.
The rib material 2 is also pressed against the inner wall of the steel pipe by the rigidity or weight of the welding device 23 and the welding device 11 to correct the rising. The relative position between the guide rolls 3a, 3b, 3c and the welding torch 10, the torch angle, etc. can be arbitrarily adjusted by the dials 10a, 10b, 10c in the mounting portion.

In this embodiment, the outer diameter is 318.5 mm (inner diameter 30
0.5mm) steel tube inner surface with a 13mm diameter steel wire with an envelope diameter of 295mm,
Insert a spirally shaped one with a pitch of 300 mm,
Welding was performed with this device. The guide roll dimensions are as follows: horizontal rolls 3a and 3b have a diameter of 25 mm, a thickness of 15 mm, and a roll interval of 14 mm.
The vertical roll 3c has a diameter of 25 mm and a thickness of 13 mm, and is behind the horizontal roll.
It was placed at a position of 20 mm. Arm 23 has an outer diameter of 220 mm and a length of 5
It is made of m steel pipe, and the sliding length of the slide mechanism 32 is 150 mm. Welding results were good over the entire length of the rib material, pitch deviation did not occur, and it was possible to manufacture a steel tube with internal ribs that was free of defects.

[0015]

EFFECTS OF THE INVENTION According to the present invention, the spiral ribs on the inner surface of the steel pipe can be welded properly following the preformed rib material, and the steel pipe with the inner surface spiral rib can be manufactured without any trouble.

[Brief description of drawings]

FIG. 1 is a front view of a welding device according to an embodiment of the present invention.

FIG. 2 is a partial detailed view of FIG.

FIG. 3 is a partial detailed view of the welding apparatus according to the embodiment of the present invention.

FIG. 4 is a sectional view taken along the line AA of FIG.

FIG. 5 is a partial side view of the welding apparatus according to the embodiment of the present invention.

FIG. 6 is a partial front view of the welding apparatus as viewed from BB in FIG.

FIG. 7 is a graph showing a change in pitch of a rib material before and after welding.

[Explanation of symbols]

 1 Steel pipe 2 Rib material 3 Guide roll 10 Welding torch 11 Copy welding device 20 Base 21 Rail 22 Strut 23 Arm 24 Traveling trolley 25 Chuck 26 Rotating mechanism 27 Sliding trolley 28 Turning roller 29 Connecting rod 30 Fixed hardware 31 Movable hardware 32 Sliding mechanism

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B23K 37/047 502 E02D 5/28 7005-2D 5/56 7005-2D

Claims (2)

[Claims] 1. A steel pipe holding mechanism (25, 26, 28) for rotating a steel pipe (1) into which a rib material (2) formed in a spiral shape is inserted while holding the steel pipe in the horizontal direction, and a column (22) for the horizontal direction. A profile welding mechanism (1) attached to the tip of an arm (23) extending in the direction of the arm through a lengthwise sliding mechanism (32).
1) and a feed mechanism (24, 27, 29) for relatively moving either the copy welding mechanism or the steel pipe holding mechanism in the length direction of the steel pipe (1), the inner spiral of the steel pipe. Rib welding equipment. 2. A profile welding mechanism (11) presses a spiral rib material (2) inserted into the inner surface of a steel pipe from above.
A base roll and a pair of guide rolls (3a, 3b, 3c) in which two rolls supported from both sides form a predetermined spiral angle and a welding torch (integrally connected thereto) 10. The steel pipe inner surface spiral rib welding device according to claim 1, which is composed of