JPH07115212B2 - Butt joining method and joining device for pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention can be easily performed, for example, at the time of joining pipes such as steel pipe piles and steel pipe sheet piles at a construction site or the like, particularly in vertical jointing work. The present invention relates to a butt-joining method for pipes and a butt-joining device capable of obtaining reliable joint quality in a short time.

(Prior art) For example, most of the conventional joining work of pipes such as steel pipe piles and steel pipe sheet piles at a construction site, in particular, vertical jointing work, is arc welding at the groove after the pipes are butted. It was carried out by applying the welding joining method of performing.

However, performing the vertical jointing of pipes by this welding joining method has the following problems. That is, when the pipe to be joined is a large-diameter pile or a thick-walled pile, for example, the total welding length becomes considerably large, and a lot of time is required for joining. In particular, when the pipe to be joined is a thick pile, as shown in the schematic cross-sectional view of FIG. 5, from the viewpoint of securing the joint strength, However, it is necessary to perform multi-layer welding, which requires a high degree of skill in the work, and the quality of the welded part was not stable. Furthermore, depending on the working conditions of the welded joint, the quality of the welded part was not stable. There was a problem.

Therefore, the present applicant has previously proposed a joining method and a joining device capable of solving such a problem in the vertical jointing of pipes by the welding joining method, and particularly capable of dramatically reducing the time required for joining. It was proposed by JP-A-62-97784. This proposal states, "Two pipes to be joined whose pipe ends are abutted while sandwiching an insert material are respectively sandwiched by a pair of clamp mechanisms joined by a connecting body, and the pipes to be joined are held in this state. The butt-joining method for pipes is characterized by performing diffusion bonding by heating the vicinity of the butt-joint. " In this proposal, as the insert material, in consideration of maintaining the strength of the joint part,
An amorphous foil that does not leave an oxide at the joint is suitable.

That is, the butt-joining method for pipes according to this proposal is that the pipes to be joined are first butted against each other and held, and the pipes to be joined are heated and pressurized to an extent that plastic deformation does not occur and diffusion of atoms generated in the joint surface is used. This is a method of joining at a temperature below the melting point of.

(Problems to be Solved by the Invention) However, if the invention proposed in Japanese Patent Laid-Open No. 62-97784 is directly applied to the joining of steel pipe piles, the entire joint portion should be covered according to the dimensions of the steel pipe piles and the like. It is necessary to heat the pipes to be joined by using a heating device having a size capable of Therefore, when the pipes to be joined are large in size, such as large-diameter piles and thick-walled piles, the heating device inevitably has to be large, and accordingly the heating capacity of the heating device is large. (Electric power) becomes large, workability at the site is significantly reduced, and it also contributes to an increase in construction cost (electric power).

Thus, for example, in butt-joining pipes such as large-diameter piles and thick-walled piles used as landslide restraining materials, Japanese Patent Application Laid-Open No.
If the invention proposed by Japanese Patent Laid-Open No. 97784 is simply used as it is, the workability is poor because the heating device and the power supply device are large, and the construction cost may be significantly increased.
Therefore, the invention proposed by JP-A-62-97784 could not be easily applied to the large-diameter piles, the thick-walled piles, and the like as described above.

In view of the above situation, an object of the present invention is to provide a pipe butt-joining method and a pipe butt-joining device that are efficient and have excellent workability in the field.

(Means for Solving the Problems) The inventors of the present invention have conducted various studies in order to solve the above problems, and as a result, the diffusion bonding method proposed by JP-A-62-97784 is applied to steel pipe piles and steel pipe sheet piles. When applied to the in-situ joining of pipes, etc., it is efficient with a small-capacity power source by using a mobile and small heating device to partially heat the joint part in sequence along its periphery. Therefore, it was found that it is possible to raise the temperature of the joint and maintain the temperature.

In addition, in order to prevent the thermal expansion that occurs in the pipe during heating, the fixing device is provided to fix the pipe, and if necessary, to prevent oxidation of the joint surface, inertness to the inside and outside of the pipe is required. The present invention has been completed by finding that a joint with stable quality can be obtained by providing an inert gas filling device for feeding gas.

Here, the gist of the present invention is to butt and hold the respective joint surfaces in a state where the insert material is sandwiched, and to heat the joint surfaces to perform diffusion joining in a butt joint method for pipes, in which the heating is performed. Is a butt-joining method for pipes, characterized in that the joining surface is partially heated sequentially along the circumference thereof.

In addition, from another surface, there is provided a butt-joining device for joining two tubes butted with each other with an insert material sandwiched therebetween by heating the respective joining surfaces, (i) the joining surface Mobile heating device having a part of the heating device and a traveling device that is movable in the circumferential direction of the joint surface while supporting the heating device, and (ii) fixing for fixing and holding the two pipes. A device, and, if necessary, (iii) a device for butt-joining pipes, characterized by comprising a device for filling an inert gas in the joint portion of the two pipes.

In the butt-joining method for pipes and the butt-jointing device for pipes according to the present invention, similar to the conventionally known diffusion bonding,
Examples of the "insert material" include Fe-based or Ni-based amorphous foils to which a melting point depressing element such as B, Si, and P is added.

Further, the pipe to which the butt joining method and the butt joining device according to the present invention can be applied is a pipe used in civil engineering work or construction work, and specifically, a large diameter or thick steel pipe pile or steel pipe. A sheet pile etc. can be illustrated.

(Operation) Hereinafter, the present invention will be described in detail together with operation effects.

First, a butt joint method for pipes according to the present invention will be described.

In the butt joining method for pipes according to the present invention, the joining surfaces of the respective pipes are butt-fixed and fixed while sandwiching the insert material,
When heating the bonding surface to perform diffusion bonding, the heating is performed by partially and sequentially heating the bonding surface along the circumference thereof.

When the joining surface reaches the joining temperature by the heating, only the insert material becomes the liquid phase, and the gap between the joining surfaces is filled with the molten metal. Then, if the temperature is kept constant at the joint temperature, mutual diffusion occurs between the insert material in the liquid phase and the base material, and the melting point depressing element in the insert material diffuses to the base material side, so the melting point of the molten metal gradually increases. Rise to. Then, the molten metal is finally isothermally solidified, and the bonded portion has a uniform structure that does not leave a solidified structure, and the bonding is completed. In the meantime, in the present invention, in the present invention, the quality of the joint is kept more stable by the rapid cooling accompanying the sequential heating of the joint.

Here, “sequentially heating” includes a case where the heating means is moved and a case where the heating means is provided over the entire circumference and the heating point is moved. Either of them may be used, but the former means is more preferable. The device becomes compact.

That is, unlike the conventional case, since the entire circumference of the joint surface is not heated at the same time, the heat capacity per unit time required for heating, that is, the heat capacity of the heating device can be suppressed, and a small-capacity electric power facility can be used in the field. As a result, it is possible to prevent an increase in construction cost (electric power amount) at the time of joining, and to reduce the size and weight of the heating device itself.

Further, the thermal strain in the circumferential direction caused by the "sequential heating" causes almost no problem in the liquid phase diffusion bonding of the present invention as compared with the case of fusion welding.

Therefore, it is possible to prevent the workability from deteriorating and the construction cost from significantly increasing even in the butt jointing of pipes such as large diameter piles and thick piles.

In the butt-joining method for pipes according to the present invention, a configuration other than the above-mentioned heating method, for example, means for butting and fixing the joining surfaces of the respective pipes with the insert material sandwiched therebetween, is a conventionally known means. According to, there is no limitation whatsoever. For example, as disclosed in Japanese Patent Application Laid-Open No. 62-97784, means for using a clamp mechanism connected by a connecting body is exemplified.

That is, the butt-joining method for pipes according to the present invention can solve the problems of the conventional techniques with a simple structure.

Next, a description will be given with reference to FIGS. 1 to 4 attached with a butt joint device for pipes according to the present invention.

FIG. 1 is a schematic cross-sectional view schematically showing an example of a butt joint device for pipes according to the present invention. In FIG. 1, the pipe to be welded 2 (lower pile) is placed in the ground, and the situation in which the pipe to be welded 1 (upper pile) is joined onto this pipe to be welded 2 (longitudinal joint). Shows.

In the butt-joining device for pipes according to the present invention, as described above, the pipe to be joined 1 (upper pile) and the pipe to be joined 2 (lower pile).
Since the mobile heating device 4 that can sequentially heat a part of the joint surface 3 of the above is used along the circumferential direction, the heat capacity of the mobile heating device 4 can be reduced, and Even for piles with a large diameter and thick ones, it is possible to efficiently and reliably raise and maintain the temperature with a small-capacity heat source.

As shown in FIG. 2 which is a schematic enlarged view of the mobile heating device 4, the mobile heating device 4 has a heating device, for example, a high-frequency heating coil 15 on the welded pipe 1 and the welded pipe 2 side, and the heating coil 15 It has a traveling device composed of a wheel 17, a rail 8 and a traveling guide 7 which are movable in the circumferential direction of the joint surface 3 while supporting the movable heating device 4.
Rear surface (in the moving heating device 4, the heating coil 15
Adjacent to each other) has a water cooling section 16. The heating coil 15 and the water cooling unit 16 are covered with a steel cover 14.

In addition, from the viewpoint of preventing the oxidation of the joint surface 3, it is also possible to supply an inert gas to the vicinity of the joint surface 3 on the outside of the joint pipe 1 and the joint pipe 2 via the periphery of the heating device 4. Is desirable. In FIG. 2, a space is provided between the heating coil 15 and the water cooling part 16 and the steel cover 14, and the other end thereof is fed from a tube 13 connected to an inert gas supply device (not shown). The inert gas thus obtained is pressure-fed in the space (in the direction of the arrow in FIG. 2) and finally supplied between the heating coil 15 and the pipes 1 and 2 to be joined. ing. That is, the inert gas can be supplied to the joint surfaces outside the two pipes to be joined and the vicinity thereof.

The traveling device used in the movable heating device 4 is, for example, as shown in FIG. 1, fixing bolts provided at, for example, two or four points along the circumferential direction of the pipe 2 to be joined, for example, in the radial direction thereof. By means of a head fixed to the pipe 2 to be joined, a traveling guide 7 provided on the head, a traveling rail 8 provided on the traveling guide 7, and a wheel 17, and the moving on the rail 8 It can be illustrated that the heating device 4 is configured to be able to travel on the circumference along the joint surface 3. In any case, a device that can move in the circumferential direction of the joint surface 3 while supporting the heating coil 15 may be used.

The moving conditions (moving speed, etc.) of the mobile heating device 4
Can be appropriately determined and adjusted according to the conditions of the pipes 1 and 2 to be welded, such as the plate thickness of piles that are the pipes 1 and 2 to be welded, the heat capacity, and the like, without any limitation.

Further, the butt-joining device for pipes according to the present invention has, in addition to the movable heating device 4, a fixing device for fixing and holding the two pipes to be joined, and further, if necessary, the two pipes. It has an inert gas filling device for supplying an inert gas to the joint surface inside and outside the pipe and the vicinity thereof. Therefore, these devices will be described next.

These devices may be the same as those used in the conventional butt-joining device for pipes and are not particularly limited. As shown in FIG. 1, for example, as a fixing device, ribs 6 are provided on each of the joined pipe 1 and the joined pipe 2 in order to prevent a joining defect due to thermal expansion of the joined pipe 1 and the joined pipe 2. Are temporarily fixed by welding, for example, and the steel bars 5 are made to penetrate through these ribs 6, and the steel bars 5 are fixed to each other by a fixing tightening nut 9.
Further, in the circumferential direction of the pipe to be welded 2, a desired pressure can be applied to the pipe which is the pipe to be welded by tightening at two points and then heating. As a method of fixing the ribs 6, other than welding to the upper pile, it is conceivable to tighten and fix the ribs 6 in the form of, for example, a half band.

The pressing force at this time is preferably 0.4 kgf / mm ² or more, and more preferably about 1 kgf / mm ² . Thereby, the thermal expansion generated in the pipes 1 and 2 to be joined can be reliably suppressed. Further, it is desirable that the heating temperature at the time of pressurization / bonding is about 1200 to 1280 ° C. from the viewpoint of securing the strength and quality of the welded portion.

Further, the inert gas filling device is effective for preventing the oxidation of the joint surface 3, and it is desirable to provide it inside and outside the joint pipe 1 and the joint pipe 2, respectively, as shown in FIG.

Regarding the inert gas filling device provided inside the pipe, the partition plate 10 is set inside the pipe 2 to be joined, and the blowing nozzle 12 connected to an inert gas supply device (not shown) provided outside is set. The partition plate 11 (a schematic perspective view of which is shown in FIG. 4) is set inside the pipe 1 to be joined. In this way, the internal space near the joint surface 3 is sealed, and the inert gas is supplied / filled into the space from the blowing nozzle 12. Then, after this, the tube butt joining method according to the present invention may be performed.

As already described in detail with reference to FIG. 2, the inert gas filling device provided outside the pipe has a steel cover 1
By embedding the tube 13 and the heating coil 15 so that the tube 13 constantly radiates the inert gas to the heating coil 15, the emulsification in the heating part and its vicinity can be prevented.

Further, the present invention will be described based on examples, but this is merely an example of the present invention and is not limited to the present invention.

(Example) When the conventional welded joining method shown in FIG. 5 was used to perform vertical jointing of large diameter piles (outer diameter: 406 mm, wall thickness: 25 mm),
A comparison was made with the case where cascading bonding (using a Ni-based amorphous foil) was performed on the completely same pile by the apparatus and method according to the present invention shown in FIGS. 1 to 4.

The results are shown in Table 1.

As is clear from Table 1, in the large diameter pile and the thick wall pile joined by the conventional joining method, the number of welding passes increases,
It can be seen that a great deal of time, electricity, and skill are required.

On the other hand, in the example of the present invention, it can be seen that extremely good results could be obtained for the thick-walled pile, which has been conventionally considered to be not easy to be longitudinally joined.

(Effects of the Invention) As described in detail above, according to the present invention, butt joints of pipes such as thick-walled steel pipe piles and large-diameter piles represented by landslide restraining materials, etc., without increasing the construction cost, for example, on-site. In the vertical jointing, the construction period and the construction cost can be greatly reduced, and it is possible to achieve a groundbreaking improvement in terms of quality assurance.

The practical significance of the present invention having such effects is extremely remarkable.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a butt-joining device for pipes according to the present invention; FIG. 2 is a schematic cross-sectional view showing in enlarged form a mobile heating device used in the butt-joining device for pipes according to the present invention. FIG. 3 is a schematic explanatory view showing an example of an inert gas filling device inside and outside the pipe, which is performed as necessary in the butt-joining method and joining device for pipes according to the present invention; FIG. 5 is a schematic perspective view of a partition plate used in the inert gas filling device; and FIG. 5 is a schematic explanatory view showing an example of welding and joining a conventional large-diameter thick-walled pile. 1: Upper pile, 2: Lower pile 3: Joining surface, 4: Movable heating device 5: Steel rod, 6: Steel overhanging rib 7: Travel guide, 8: Travel rail 9: Fixed tightening nut, 10: Partition plate (For lower pile) 11: Partition plate (for upper pile), 12: Blowing nozzle 13: Blowing tube, 14: Steel cover 15: Heating coil, 16: Water cooling part 17: Wheel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Miyazaki 1-3-3 Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries, Ltd. (72) Inventor Fumio Kashimoto 4-chome Kitahama, Chuo-ku, Osaka-shi, Osaka No. 33 Sumitomo Metal Industries, Ltd.

Claims (3)

[Claims] 1. A butt-joining method for pipes, wherein the joining surfaces are butted against each other while sandwiching an insert material, and the joining surfaces are heated to perform diffusion joining. A butt-joining method for pipes, characterized in that heating is carried out partially and sequentially along the circumference. 2. A butt-joining device for joining two pipes, which are butt-butted with each other with an insert material sandwiched between them, by heating the respective joint surfaces, (i) a part of the joint surfaces And a movable heating device having a traveling device that is movable in the circumferential direction of the joint surface while supporting the heating device, and (ii) a fixing device that fixes and holds the two pipes. A butt joining device for pipes, which is characterized in that 3. The butt-joining device according to claim 2, further comprising a device for filling an inert gas in the joint between the two pipes.