JPH03230874A - Method for joining reinforcing bars - Google Patents

Abstract

PURPOSE:To obtain joining of high quality without weakness by ribs by operation at high speed by inserting a steel disk provided with amorphous material thin layers between the end faces in opposition to joint the reinforcing bars. CONSTITUTION:The amorphous material thin layers 12 are formed on both sides of the steel disk 10 with various thicknesses having the outside diameter almost equal to the maximum diameter of the reinforcing bars 1 and 1 and the steel disk 10 with thickness in accordance with an interval between the end faces 1a and 1a in opposition is inserted between the end faces 1a and 1a in opposition of the corresponding reinforcing bars 1 and 1 to be connected in both major assembly reinforcing bars and then, both end faces 1a and 1a are abutted on each other via the disk 10 and both end faces 1a and 1a are joined by high-frequency induction heating. By this method, since the ribs 7 in the longitudinal direction on both sides of a joined part are perfectly coupled with the disk 10, respectively, the rib part does not cause weakness of joining.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for joining reinforcing bars, and more particularly to a method for joining reinforcing bars through a thin layer of amorphous material.

[Conventional technology]

Electric welding and gas welding are used to connect reinforcing bars when constructing reinforced concrete structures.
These conventional methods require a skilled worker to carry out the connection work, and the connection surfaces are not smooth, resulting in poor workability. In order to solve these problems, an amorphous connection as shown in FIG. 3 has been proposed. This involves inserting a thin piece of amorphous material 3 (approximately 20-50 μm thick) with a low melting point between the reinforcing bars 1 to be connected, heating the joint using high-frequency induction heating, and diffusing the molten brazing filler metal. It is meant to be joined. This amorphous bonding has the following features: (a) High-quality bonding can be obtained with high-speed operation. (b) There is no protrusion at the joint and a smooth surface can be obtained. (C) Can be joined using a simple automated device. (d) Not only carbon steel but also stainless steel can be joined. It has the following advantages and is expected to become popular.

[Problem to be solved by the invention]

However, actual reinforcing bars have longitudinal ribs 7 as shown in Figure 5, and if these longitudinal ribs 7 are not aligned, the joint becomes a weak point, so there is a drawback that it takes time and effort to align the ribs. . Depending on the structure to be constructed, a plurality of vertical reinforcing bars 1■ and a plurality of horizontal reinforcing bars LH may be intersected as shown in Fig. 4.
Large reinforcing bars 18a, 18 formed by joining those intersections
In some cases, the reinforcing bars are manufactured in advance at a reinforcing bar workshop, and then brought to the construction site and then the large sets of reinforcing bars are joined together. For example, when connecting the large reinforcing bars 18a and 18b in Fig. 4 in the horizontal direction, the pair of horizontal reinforcing bars 1H at the top of both large reinforcing bars 18a and 18b, and the pair of horizontal reinforcing bars IH second from the top. , 3 from the top
It is necessary to join pairs of corresponding reinforcing bars to be connected, such as the pair of horizontal reinforcing bars IH, etc., but the distance between the opposing end faces of the corresponding reinforcing bars to be connected must be strictly equal in each pair. It is difficult to do so. Due to the unequal spacing between the opposing end faces of the corresponding reinforcing bars to be connected, it has conventionally been considered impossible to connect the large set reinforcing bars 18a, 18b using the amorphous thin piece 3 of a constant thickness. Therefore, an object of the present invention is to provide an amorphous joining method for reinforcing bars that does not have weak points due to ribs, and an amorphous joining method that does not require high dimensional accuracy of large set reinforcing bars.

[Means to solve the problem]

Referring to the embodiment shown in FIG. 1, according to the reinforcing bar joining method according to the present invention, both sides of a steel disk 10 of a required thickness and having an outer diameter approximately equal to the maximum diameter of the reinforcing bar 1 having longitudinal ribs 7 are assembled. A thin amorphous material layer 12 is formed on the reinforcing bars 1 to be connected, and after inserting the disk 10 between the opposing end surfaces 1a of the reinforcing bars 1, the end surfaces 1a are butted together via the disk 10, and the end surfaces are joined by high-frequency induction heating. do. In FIG. 1, the thickness of the thin layer of amorphous material 12 is shown greatly exaggerated;
The thickness T (FIG. 2B) of the disk IO is substantially unaffected by the thin layer 12 of amorphous material. The amorphous material used in the above reinforcing bar joining method of the present invention melts at a relatively low temperature of, for example, about 1200° C., diffuses into the crystal structure of the reinforcing bars, and acts as a "brazing material". Examples of such materials include Fe-8i-B amorphous materials and Ni-Cr-8L-B amorphous materials. The above-mentioned high-frequency induction heating in the present invention provides sufficient heating to melt the amorphous material at the joint and cause it to diffuse into the reinforcing steel. The method of joining large sets of reinforcing bars according to the present invention will be explained with reference to FIGS. 1 and 4. A plurality of horizontal reinforcing bars IH and a plurality of vertical reinforcing bars 1
One large set of reinforcing bars 18 of the structure that intersects and joins the intersections
In the method of mutually joining the reinforcing bars 18b with another large set of reinforcing bars 18b having the same structure as the reinforcing bars IH. A thin layer of amorphous material 12 is formed on both sides of steel disks 10 of various sizes having an outer diameter approximately equal to the maximum diameter of 1.
After inserting the disk 10 having a thickness corresponding to the distance between the opposing surfaces between the opposing end surfaces of the corresponding reinforcing bars IH or IV to be connected in both large sets of reinforcing bars, both end surfaces are connected through the disk 10. Match,
The end faces are joined by high frequency induction heating.

[Operation] As is clear from FIGS. 2B and 2A, which are a side view and a sectional view of the joint of reinforcing bars 1 joined by the method shown in FIG. 1, the longitudinal ribs 7 on both sides of the joint are circular. Since it is completely bonded to the plate IO, the rib portion will not become a weak point in the bond. Therefore, one of the objects of the present invention, ``providing a method for amorphous joining of reinforcing bars without weak points caused by ribs,'' is achieved. According to the large reinforcing bar joining method of the present invention shown in FIG. Since it is absorbed by inserting the disk 10 having a thickness corresponding to the thickness, the dimensional accuracy during manufacture of the large set reinforcing bars 18aS18b does not need to be particularly high. Therefore, another object of the present invention, ``providing an amorphous joining method that does not require high dimensional accuracy of large assembled reinforcing bars,'' is achieved.

【Example】

Although the reinforcing bar 1 used in the embodiment of FIG. 1 also has circumferential ribs, the method of the present invention can be carried out regardless of the presence or absence of circumferential ribs. In FIG. 4, the explanation has been made assuming that the large reinforcing bars 18aS18b are connected in the horizontal direction, but the method of the present invention can be similarly applied to the connection in the vertical direction. In addition, large reinforcing bars 1
Connect 8a and 18b to vertical vertical reinforcing bar 1■ and horizontal horizontal reinforcing bar LH.
However, the method of the present invention is equally applicable to large reinforcing bars having such a structure as well as large reinforcing bars that intersect at any angle. FIG. 6 shows a joining method when the end surfaces 1a of the corresponding transverse reinforcing bars IH to which adjacent large reinforcing bars 18a and 18b are to be connected do not face each other, but their end portions overlap. Flat cutting surfaces 16 are formed on opposite sides of both end portions, and after inserting an amorphous material thin piece 14 between both cutting surfaces 16, both cutting surfaces 16 are cut through the amorphous material thin piece 14.
are butted together, and the cut surfaces 16 are joined by high-frequency induction heating. This method of using the cut surface 16 and the amorphous material thin piece 14 can be applied not only to the horizontal reinforcing bars IH but also to the vertical reinforcing bars 12 as needed. According to the method shown in FIG. 6, there is no need for high dimensional accuracy in the large set reinforcing bars.

【Effect of the invention】

As described above in detail, the method for joining reinforcing bars of the present invention involves inserting a steel disk provided with a thin layer of amorphous material between opposing end faces to join reinforcing bars, and thus has the following effects. (a) There is no need to align the longitudinal ribs, improving work efficiency. (b) Amorphous joining of reinforcing bar members can be carried out without requiring special dimensional accuracy even in large assemblies of reinforcing bars. (c) There is no reduction in cross section at the reinforcing bar joint, and the joint does not become a weak point. (d) Rebar joints without protrusions can be formed regardless of the presence or absence of longitudinal ribs.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the method of the present invention, Figures 2A and 2B are a cross-sectional view and side view of a joint, Figure 3 is an explanatory diagram of an amorphous joint, Figure 4 is an explanatory diagram of a large set of reinforcing bars, FIG. 5 is an explanatory diagram of longitudinal ribs, and FIG. 6 is an explanatory diagram of another embodiment for joining large set reinforcing bars. 1...Reinforcing bar, 1a...End face, IH...Horizontal reinforcing bar, 1■...Vertical reinforcing bar, 3...Amorphous thin piece,
5... Heating coil, 7... Longitudinal rib, 10.
... Disc, 12... Amorphous material layer, 14.
... Amorphous material thin piece, 16 ... Cutting surface, 8a1 18b ... Large assembly reinforcing bar.

Claims (3)

[Claims] (1) Form a thin layer of amorphous material on both sides of a steel disk of the required thickness and having an outer diameter approximately equal to the maximum diameter of the deformed reinforcing bars, and insert the disk between the opposing end surfaces of the reinforcing bars to be connected. A reinforcing bar joining method in which both end faces are then butted together via the disc, and the end faces are joined by high frequency induction heating. (2) In a method of joining one large set of reinforcing bars of a structure in which a plurality of horizontal reinforcing bars and a plurality of longitudinal reinforcing bars intersect and join the intersections, and another large set of reinforcing bars of a similar structure, the maximum diameter of the reinforcing bars is approximately A thin layer of amorphous material is formed on both sides of steel discs of various thicknesses with the same outer diameter, and a thin layer of amorphous material is formed between the opposite end faces of the corresponding reinforcing bars to be connected in both large sets of reinforcing bars according to the spacing between the opposing faces. A reinforcing bar joining method comprising: inserting the disc having a thickness of 100 ml, and then butting both end faces together via the disc, and joining the end faces by high-frequency induction heating. (3) In the reinforcing bar joining method according to claim 2, at least a part of the two large set reinforcing bars is provided with an end portion that overlaps the corresponding reinforcing bar to be connected, and the overlapping side surfaces of the end portions are cut into a planar shape. A reinforcing bar joining method comprising inserting a thin piece of amorphous material between the opposing surfaces, abutting both cut surfaces through the thin piece, and joining the cut surfaces by high-frequency induction heating.