JPS62104621A - Production of double pipe - Google Patents

Abstract

PURPOSE:To bind plural unit pipes relatively and to obtain a long sized double pipe by melting an adhesive by heating from the outside by relatively stratifying plural unit pipes via an adhesive and by giving cooling action after giving pipe reducing action on the outside pipe as well. CONSTITUTION:A pipe stock 5 is formed by stratifying a brazing filler metal 4 on the outer pipe 1 by coating it spirally on the outer face of the inner pipe 2 by turning the inner pipe 2 for the outer pipe 1 and by extracting the brazing filler metal 4 which is in the melting state of a coating device 3 as well, in case of stratifying the inner pipe 2 on the outer pipe 1. Then, the pipe stock 5 is faced to the tip of a double pipe producing device 7, the outer pipe 1 is expanded with its heating by the high frequency induction heating device 8 provided on the base part thereof and the brazing filler metal is re-melted and filled up in the gap of the pipe stock 5. Both pipes 1, 2 then become in binding state with the inner pipe 2 receiving the pipe reducing action as well when the rolling and pipe reducing actions are given to the outer pipe by rollers 11, 11.... A long sized double pipe 6 is then formed by promoting the binding action by giving the cooling action with water, shower device 12.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology belongs to the technical field of manufacturing a double-walled pipe, such as a double pipe, which has corrosion resistance and wear resistance.

<Summary of the gist> Accordingly, the present invention provides a method for forming an inner tube into a relatively single layer on an outer tube by interposing an adhesive such as a brazing filler metal on one or both of the opposing surfaces. This invention relates to a method for manufacturing a double-walled pipe in which the pipes are made into a blank pipe and then mechanically tied together.In particular, the invention relates to a method for manufacturing a double-walled pipe in which a plurality of units of inner and outer pipes are layered relative to each other via an adhesive. After that, heating is applied from the outside of the outer tube to increase the diameter of the outer tube, melting the interposed adhesive, and then mechanically rolling the outer tube side with a roll or the like to reduce the diameter. This invention relates to a method for manufacturing double-layered pipes in which all unit pipes are then relatively tightly connected by further applying a cooling effect using water spray or the like.

<Prior Art> As is well known, piping is used in all industries not only for fluid transportation and information transmission, but also as a member of structures.

Therefore, it is extremely important to provide these pipes and pipes (A) with corrosion resistance and wear resistance to withstand long-term use, and various technologies have been developed to deal with this problem. In many cases, these important conditions are not required singly but in combination, and materials that satisfy all the conditions have not been practically developed, for example, for the outer tube. Dual pipes such as two-way pipes that have high pressure resistance and corrosion and wear resistance are now being used. Double pipes and double pipes made of hydraulically expanded pipes Various types of double pipes have been developed.

<Problems to be solved by the invention> Of the conventional methods for manufacturing double pipes, for example,
Since cratted steel pipes and the like undergo hot treatment during manufacture, they have the disadvantage that the manufacturing process is complicated, the equipment used is expensive, and the manufacturing management is complicated.

In hydraulic pipe expansion, it is difficult to seal high pressure water, and
The shrink fit method has the disadvantage that it is difficult to perform pre-processing such as dimensional adjustment, and it is also difficult to manufacture long tubes.

In addition, in case of bonded double pipes other than crat steel pipes, if the degree of tightness between the inner and outer pipes is not spread over the entire area on a microscopic level, hydrogen gas etc. may be generated and accumulated in the gap between the two pipes. However, there was also the inconvenience that the performance of the JQ-equipped double tube itself was affected.

The purpose of this invention is to solve the technical problem of manufacturing double pipes such as double pipes based on the above-mentioned prior art, and to improve the degree of tightness of the resulting double pipes such as double pipes, and to The gaps between the unit tubes are completely filled to prevent the accumulation of hydrogen gas, etc., and long tubes can be obtained, making management and maintenance during manufacturing easier, and improving manufacturing accuracy. It is an object of the present invention to provide an excellent pitcher pipe manufacturing method that can be manufactured at a low cost and is beneficial to piping technology applications in various industries.

<Means/effects for solving the problems> In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the scope of the above-mentioned patent claims, is to The blank tube is made by layering the adhesive such as wax on the entire surface between the opposing surfaces to form a blank tube.The blank tube is passed through a heating device and heated from the vertical side, and the outside and inside are heated to a temperature. By applying a difference to the outer tube and increasing the diameter, the adhesive on the mutual surfaces of each unit tube is melted so that the bonding surfaces are interposed everywhere, and the tube is rolled through hooks, rolls, etc. Provides a tube shrinkage effect to bring all unit tubes into close contact with each other, then provides a cooling effect using water, showers, etc. to cool the outer unit tubes to promote tube shrinkage, resulting in tight double tubes, etc. Technical measures were taken to make it possible to obtain double-walled pipes.

<Embodiment> Next, an embodiment of the present invention will be described as follows based on the drawings.

The illustrated embodiment is a method of manufacturing a corrosion-resistant two-way tube. First, as shown in FIG. When the inner tube 2 made of stainless steel as a unit tube with a variable external shape is used, and when the inner tube 2 is layered relative to the outer tube, the inner tube 2 is rotated relative to the outer tube 1. The melted brazing material 4 is poured onto the outer surface of the inner tube 2 by the applicator 3 heated by an appropriate heating device, and the brazing material is melted by the rotation of the inner tube 2 and the pushing action against the outer tube 1. 4 is applied in a spiral manner to the entire outer surface of the inner tube 2, and is layered relative to the outer tube 1.

Then, the inner tube 2 is laminated relative to the outer tube 1 via the brazing material 4, and a blank tube 5 is formed as a raw material.

In this state, the wax A interposed between the outer tube 1 and the inner tube 2 is primarily coated over the entire surface, and if left untreated, Since the brazing filler metal is in a cooled state, the trimmings of the outer tube 1 and the inner tube 2 are connected to each other.

Next, as shown in FIG. 2, when converting the raw tube 5 into a double double tube 6, the double tube manufacturing device 7 is directed to the tip, and the high frequency induction 59 heating device 8 provided at the base is first As a result, a heating action is applied from the outside of the outer tube 1 to increase the diameter of the outer tube 1, and the wax 4 interposed between the outer tube 1 and the inner tube 2 is melted again to form a relatively overlapping layer. It is made to be carried out all over the minute clearance gap that forms the pipe 5.

Then, from this state, it is divided into rigid directions as shown in FIG. 4, and is connected to each other in the circumferential direction by a universal joint 1 (), and a roller 11 . 11, the inner tube 2 is subjected to a rolling action (pulling and unwinding action), and the inner tube 2 is also subjected to a shrinking action. The brazing material, which had been interposed between the outer tube 1 and the inner tube 2 and was spread everywhere by heating, is further spread microscopically between the two tubes.

Then, in the next step, the double pipe rolled and fed out from the rollers 11, 11, etc. is cooled all around by water and the wrinkle device 12, and further subjected to a pipe shrinking action. In particular, the contraction effect of the outer tube 1 becomes remarkable, the fitting margin between the two becomes large, and the tightening effect of the outer tube 1 and the inner tube 2 is greatly promoted. The brazing filler metal uniformly spreads over one microscopic area, and the cooling effect mechanically and firmly connects both tubes, reducing the double tube 6 of C゛ to a small and medium tube. Even if the raw tube 5 shown in FIG. 1 is a considerably long tube, the double tube 6 can be formed into a long tube with a considerable length by the rolling action of the []-ra 11, 11... I can do it.

The state of the double tube 6 thus obtained is as shown in FIG. Although it is thin like a film, it penetrates microscopically into the opposing surfaces of both tubes, and connects both tubes well both overall and locally.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments, and double pipes can be applied not only to corrosion-resistant pipes but also to the manufacture of wear-resistant pipes, and double-layer pipes can be applied to the production of wear-resistant pipes. Minara size,
It can also be applied to the production of double pipes or double pipes of four or more medium pipes.

The target duplex pipes are not only fluid transport pipes, but also various types of pipes, such as architectural structural members and tubes such as the neck of the neck.

<Effects of the Invention> As described above, according to the present invention, basically when producing a light weight product such as a double pipe and a wear-resistant double pipe, the outer unit pipe and the inner unit pipe, or The inner unit tube is strongly mechanically connected (J
It has the excellent effect of improving the braking durability of the manufactured double pipe.
In addition, since the adhesive such as the thin film brazing filler metal that is interposed between each unit tube is distributed uniformly throughout the entire body, abdomen, and microscopically, it is only possible to , the tube to the inner unit 1 (not only connects the tube), but also functions as a kind of filler and sealing material, and can suppress the accumulation of generated hydrogen, etc., and from this point of view, the performance and durability of the double tube is improved. It has an excellent effect of improving sexual performance.

In addition, the reduction in heat transfer rate that is caused by the shortcomings of mechanically fitted double pipes can be prevented by using an adhesive such as a metal brazing material, and it can be effectively used as heat transfer tubes in heat exchangers. There is an effect that works.

Therefore, when forming the inner and outer tubes into a relatively single layer, the gaps between the opposing surfaces of each unit 1 to the tubes are thoroughly coated with wax 4'lJ, etc., and a3 The manufacturing process has the advantage of being able to interpose adhesives evenly on thousands of layers of raw pipes.
In this case, when the tube contraction action is required from the outer tube side, the adhesive interposed in the process of increasing the diameter of the outer unit tube due to the heating action in the previous stage is melted, and the shrinkage is performed more uniformly throughout. be done.

Then, a roller or the like is used to apply a tube shrinking action to the heated outer tube to tighten each unit (~pipe), and a squeezing action is applied to the heated and molten adhesive described above to make the adhesive tertiary uniform. The immersion effect of intervening and allowing the tube to pass is absorbed, and the subsequent cooling effect causes the outer tube to become more tightly bound.
The joining of the tithe 1H of the tube to each unit 1 of 1 J: has a soaking effect of strengthening.

In this way, hot treatment is carried out as in the case of the manufacture of Clara+-1iYl tubes, etc. ] Since it is not made of cows, there is no need for any escape processes after production, which means that the production cost can be reduced by 1~.

Also, since there is no limit to the material combinations for each unit 1 to tube, such as inner and outer tubes, please contact us! 1. The effect of having a degree of freedom of choice is also suppressed.

Then, in order to give 7JO thermal effect to the outer tube in the first production, the j change i@,! There is also the effect that a high degree of fitting can be obtained through the J1 action (contraction action due to J).

Not only do the brazing filler metals firmly bond each J-knit tube, but the adhesive acts as a kind of filler, which has the excellent effect of preventing the accumulation of hydrogen scum, etc. .

In addition, 1) After the heat action in step 11, the heat is removed through the rolling action using rolls or the like, so that a double-layered long pipe can be obtained by shrinking the pipe.

[Brief explanation of drawings]

The drawings are explanatory diagrams of one embodiment of the present invention, in which Fig. 1 is a schematic perspective view of relative stacking of a raw pipe, Fig. 2 is a partial cross-sectional side view of the manufacturing process of a double-layered pipe, and Fig. 3 is a cross-sectional side view of a double-layered pipe. FIG. 4 is an enlarged perspective view of the roller. 1.2...Units (~pipe, 4...adhesive, 6.
...Double pipe Figure 3 Figure 47

Claims (1)

[Claims] In a double-layered pipe manufacturing method in which multiple unit pipes are layered relative to each other with an adhesive between opposing surfaces and then bonded together, the adhesive is melted by applying heating to the relatively layered tube from the outside. A double pipe manufacturing method characterized by applying a tube shrinking action to the outer pipe side and then applying a cooling action from the outside to tighten the raw pipes.