JPS61232062A - Relay welding method for steel pipe pile and sheet pile - Google Patents

Abstract

PURPOSE:To eliminate the need for a stopper by the projection part and to secure the uniform gap of welding zones as well by fixing the backing ring providing plural projection parts which are directed for the outer side on the periphery with hanging them on the end face of the lower pile and by performing the main welding after the spot welding of the periphery of the groove with pinching of the projection part by the upper pile and lower pile. CONSTITUTION:A backing ring 1 is inserted from the bottom part to the inner face of the head part of the driven lower pile 5 of steel pipe and the hook 6 on several places which is made by working the ring itself is held by hanging on the pipe end of the head part. Then after the spot welding of the both sides of the hook 6 on the end face of the lower pile the tip of the upper pile 4 is inserted by utilizing the taper part 8 of the ring 1 to pinch the hook 6. A fixed gap is thus secured on the periphery of the pipe end. The main welding is then performed by fixing the upper pile 4 with the spot welding of the gap part at certain intervals.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention aims to improve welding quality in on-site steel pipe relay welding of steel pipe piles and steel pipe sheet piles, reduce relay welding costs, shorten relay work time, and This article relates to an on-site relay welding method that is useful for protecting beveled edges.

(Conventional technology) The conventional on-site relay welding method for steel pipe piles and steel pipe sheet piles is
rI! The backing ring 1 shown in J is applied to the inner surface of the steel pipe relay weld. In order to hold the backing ring 1, several stoppers 2 shown in FIG. 12 are generally installed in the factory at the time the steel pipe is manufactured. are welded and fixed to the inner surface of the steel pipe at fixed positions and at fixed intervals. Then, as shown in Fig. 13, a backing ring 1 is placed on the inner surface of the head of the upper pile 5/par 2 that has been driven.
Place the upper stake 4 on the top of the upper stake 5, and set the tip of the upper stake 4 tightly to the head of the upper stake 5.
Temporarily fasten by spot welding.

If high welding quality is required for the steel pipe relay weld, a special stopper 2 and backing ring 1 are firmly welded to the contact area between the upper pile 4 and the upper pile 5, as shown in Fig. 14. It is necessary to secure a gap, or use thin small iron pieces as liners at several places when setting the upper pile 4 to secure a gap (root gap). In addition, in order to ensure welding quality, the root face of the beveled part at the tip of the upper pile is end-faced to within a standard of 0 to 2.4 mm.

Furthermore, as a prior art, there is a welded joint for steel pipe piles shown in Utility Model Application No. 47-22214, which is similar to the backing ring shown in FIG. This is a case where there is no stopper and no stopper is required.

(Problems to be Solved by the Invention) However, such conventional methods have the following drawbacks.

(a) In order to use the backing ring, a stopper is required to hold the backing ring at the relay weld on the inner surface of the steel pipe.

(b) The stoppers must be distributed evenly in the circumferential direction at a constant depth from the pipe end of the upper pile head, the number of stoppers must be varied depending on the inner diameter of the steel pipe, and they must be fixed by welding.

b) There are problems such as screw blades hitting the stopper and damaging it when using the hollow method when driving steel pipes.

) The conventional backing ring is held by a stopper, but the backing ring itself is circularly held by a plate 3 measuring 2.3 x 20 x 40, and the ring end lO is held, so there is some damage to the backing ring itself. The thickness of the backing ring is 4.5 mm or 101 mm because it needs strength to prevent it from falling off due to vibration.
A large diameter pipe of 8φ or more requires a thickness of 6 mm.

In order to ensure the quality of the welding of steel pipe relay welds, an appropriate gap is required at the contact point between the upper pile and the upper pile.

In that case, the costs of special stoppers, backing rings, welding, etc. will be high, and if a thin, small piece of steel is used as a liner, there will be a reduction in on-site relay capability or a risk of work.

(a) The root face of the beveled part at the tip of the upper pile is θ~
If 2.4 mm is not ensured, it will be difficult to ensure welding quality.

(Object of the Invention) The object of the present invention is to improve the conventional backing ring by (a)
This is an attempt to eliminate the drawback of (a).

The present invention utilizes several protrusions (hereinafter referred to as hooks) formed by processing the backing ring itself to create an appropriate gap (root gap) and its uniformity necessary to ensure the welding quality of steel pipe relay welds. The present invention aims to provide a relay welding method that can eliminate the need for a hook-based stopper and obtain good tube end quality at the beveled portion.

(Means for solving the problems) Next, regarding the backing ring according to the method of the present invention,
- Explanation will be given based on FIGS. 1 to 3. 1 and 2 are a plan view and a front view of a backing ring according to the method of the present invention, in which 1 is the backing ring main body, a straight part 9 and an inclined part 8.
Several hooks 6 are punched out from the inside to the outside in a U-shape (semicircular or square) at the same position on the circumference of the straight part 9, and the hooks 6 are punched out from the inside to the outside at approximately right angles. It is bent to form a protrusion. As shown in FIG. 3, the backing ring has a hook 6 between the upper stake 5 and the upper stake 4.
held through. This hook 6 ensures a uniform root gap between the upper piles in the circumferential direction. According to the backing ring, the conventional stopper for holding the backing ring and the plate 3 for connecting the ring ends are unnecessary, and the hook 6 can be inserted between the upper stakes and the conventional Demonstrates the same function as the backing ring. Note that 7 is a hole formed when the hook 6 is bent.

Note that the shapes of the backing ring 1 are Type I, in which the hole 7 is present on the sloped portion 8 side, as shown in FIG. 4, and Type II, in which the hole 7 is present on the straight portion 9 side, as shown in FIG. There is.

(Action of the invention) Regarding relay welding of steel pipes using the backing ring of the invention,
This will be explained using specific examples shown in FIGS. 4 to 10.

As shown in Fig. 4, a Taipei wooden ring is inserted from the bottom into the inner surface of the head of the steel pipe pile that has already been driven, and several hooks 6 made by processing the ring itself are attached to the head. Next, as shown in Figure 5, in order to hold the ring itself and to prevent the hook from breaking due to impact when it is in close contact with the upper pile, after spot welding both sides of the hook to the end surface of the upper pile, 6
As shown in the figure, the tip of the upper stake 4 is inserted into the hook 6 of the backing ring attached to the head of the upper stake 5 using the tapered part (slanted part 8) of the ring, and the hook 6 is inserted. As a result, a certain gap (root gap) is secured on the circumference of the tube end in the portion other than the hook.

Next, as shown in Fig. 7, the upper piles are fixed by spot welding the gaps at regular intervals, and the above four figures show the means of on-site steel pipe relay welding work.

FIG. 8 is a diagram showing that after beveling the ends of the steel pipe in a factory, the bottom of a type H book backing ring is inserted and the hook is brought into close contact with the root face. In the case of this type H ring, as shown in Fig. 9, the hook 6 and the steel pipe bevel are spot welded to fix the ring, and then the ring joint 10 is spot welded at 2 to 3 places from the inner surface. The movement, movement to the storage area, and shipment will proceed in this state. Figure 10 shows that the upper pile 4 with the backing ring l attached to the tip is suspended by heavy equipment from the head of the upper pile 5 after the driving is completed, and the backing ring surface is adjusted to fit tightly to the end of the lower head pipe. After that, perform temporary welding between the upper pile and the upper pile in the gap (root gap) other than the hook, and perform fixed mock welding.

When high relay welding quality is required, the gap is fixed by temporary welding, the hook part is removed by gouging, etc., and then the main welding is carried out.Zero welding itself is exactly the same as the conventional method; It is desirable to secure the ends by spot welding as shown in Figure 9.

The backing ring type and ■ of the present invention are 3.2 mm ~
Made of medium steel plate with a thickness of 4.0 mm, the ring width is 50 to 70 mm.
When welding with a diameter of 0 mm, the hook itself is melted in as part of the actual weld bead, or the ring is temporarily attached by spot welding, and then the protrusion is removed using a glider, etc. before actual welding. .

(Effects of the Invention) The present invention employs the processing method described above, and by using different backing rings and relay welding methods, l) during on-site relay welding of steel pipe piles φ steel pipe sheet piles, it is possible to perform backing without using a stopper. Since the backing ring can be held only by the hook of the ring, there is no need for a stopper and stopper welding costs.

2) The hook of the backing ring makes it easy to ensure an appropriate and uniform gap (root gap) between the upper pile and the relay weld between the upper piles, improving welding quality and making work easier.
There is no need for machining costs to secure gaps), and the cost is low!
3) Attaching the backing ring after beveling the tip of the upper pile prevents damage to the bevel and root face.

4) In the case of the previous item, work such as attaching a backing ring during on-site relay welding becomes unnecessary, and the relay setting work becomes faster.

5) Since there is only a backing ring and there are no irregularities, there is no screw damage in the medium excavation method.

6) The root face of the beveled part at the tip of the upper pile is 1 to 3.
Conventional quality can be sufficiently ensured even in millimeters.

[Brief explanation of drawings]

1 and 2 are a plan view and a front view of a backing ring according to the present invention, FIGS. 3 to 6 are diagrams showing a method for temporarily attaching a backing ring according to the present invention, and FIG. 7 is a diagram showing the backing ring according to the present invention. FIGS. 8 to 10 are diagrams showing other embodiments of the present invention, FIG. 11 is a diagram of a conventional backing ring, and FIG.
The figure shows a stopper, and FIGS. 13 and 14 show a conventional method of setting a backing ring. 1...Backing ring, 2...Stopper, 3...Plate, 4...Upper stake, 5...Upper stake, 6...Hook (protrusion), 7...By hook Hole, 8... Inclined part, 9... Straight part, 10... Ring end, 11... Root gap.

Claims (2)

[Claims] (1) When performing on-site relay welding of steel pipe piles and steel pipe sheet piles using a backing ring, a plurality of protrusions facing outward are provided on the circumference and have a thickness commensurate with the root gap of the weld. First, the plurality of protrusions are hooked onto the end face of the lower pile, and the backing ring is fixed to the lower pile by spot welding.Then, the upper and lower piles are tightly attached with the protrusions sandwiched between them, and then fixed to the specified position. Relay welding of steel pipe piles and steel pipe sheet piles, characterized by spot welding around the grooves of the upper and lower piles after securing the root gap, and performing main welding after fixing the upper and lower piles to each other. Method. (2) When performing on-site relay welding of steel pipe piles and steel pipe sheet piles using a backing ring, multiple protrusions facing outward on the circumference are provided with a thickness corresponding to the root gap of the weld. First, the plurality of protrusions are hooked onto the end surface of the tip of the upper pile, and the protrusions are spot welded, and then the bottom circumference of the backing ring inserted into the upper pile is attached to the inner surface of the upper pile at a distance. Next, the upper pile and lower pile are closely attached across the protrusion to ensure a predetermined root gap, and the grooves of the upper and lower piles are spot welded, and the upper pile is fixed by welding. A steel pipe pile characterized by performing main welding after fixing the upper and lower piles to each other.
Relay welding method for steel pipe sheet piles.