JPH03193298A - Welding method using backing member of reinforcing bar joint part - Google Patents

Abstract

PURPOSE:To execute welding which has sufficient strength by fitting a backing member to a joint part to be joined of both reinforcing bars, and thereafter, executing welding from a notch opening part of the backing member, and filling a clearance with an incombustible material so that a molten metal does not flow. CONSTITUTION:With regard to a first and a second reinforcing bars A, A', they are set to a state that a backing body 1a is fitted to its welding joint part. When a welding work is executed through a notch opening part 1b of this body, in a first and a second reinforcing bars, its joining groove parts are melted, respectively, and they are going to flow in a molten metal state by using the backing body 1a as a receiving part. A clearance between a first and a second reinforcing bars and the curved surface of the inside periphery of the backing body is closed up by an incombustible material 2, therefore, it does not occur that said molten metal flows or drops down from this clearance, and the sufficient quantity is stagnant between a first and a second joint end parts and cooled and solidified. In such a way, welding having sufficient strength can be executed easily.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides, when welding reinforcing bars, a backing member is fitted to a joint portion of the two reinforcing bars to be joined, and then Welding is carried out through the notch opening of the backing member, and at this time, the molten metal of the reinforcing bar should not flow inadvertently, and furthermore, the molten metal should not fall out, so that the desired joint weld can be achieved. The present invention relates to a welding method using a backing member for a reinforced joint.

(Prior Art) As known means for joining reinforcing bars, there are methods such as gas pressure welding, welding joints, and mechanical joints.

As for the above-mentioned welding joint construction method, whether by hand welding or semi-automatic welding, the outer periphery of the joint parts a', a', which are the ends of the reinforcing bars a, a, is made of short sections made of steel or steel material, as shown in Figure 4. 1lIIb is surrounded by a backing member C in the form of a vertical pipe, etc., and the joining groove part d of reinforcing bars a and a is
, d are welded and fixed to the backing member C by temporary fixing tubes f and f with a predetermined distance e (route spacing) apart, and welding is performed through the notch g which is open in the backing member C. By inserting a bar, both reinforcing bars a and a are welded together.

As a result, welding is completed without the molten metal of reinforcing bars a and a flowing down as described above.
In the case of the backing member C made of steel, after the joint welding of the reinforcing bars a and a is completed, the reinforcing bars and the backing member are welded to each other, making it difficult to remove them.

Therefore, visual inspection of the joint portion becomes impossible.

On the other hand, if a steel material is used for the backing member, the steel material, which is a copper plate, can be removed after welding is completed, so the appearance of the joint can be inspected. There are practical drawbacks such as increased wear and tear.

In addition, if the backing member cannot be removed as mentioned above, only the joint will have a large diameter, and the distance between reinforcing bars will not be uniform, making it impossible to obtain uniform reinforcing bars. There is also the problem that it is difficult to guarantee complete filling during filling operations.

Therefore, by considering the various drawbacks of the backing member in the above-mentioned welded joint construction method, the applicant,
Breaking away from the conventional idea that backing members were made of metal, we selected ceramics as the material so that the backing member could be crushed and removed after the welded joint was completed. In addition to making it possible to directly visually inspect the joint joint and reliably perform an external appearance inspection, it can be provided at a lower cost than steel or even copper, and it eliminates the large diameter portion left by the backing member of the joint joint. In order to enable reinforcement with uniform spacing between reinforcing bars, we proposed the methods shown in Figs. 5 and 6.

That is, the backing member i shown in FIG. 5 is made by bending a ceramic main body j into a substantially horseshoe-shaped cross section, and forming a narrow opening between the free edges of the main body j, which is inserted into the reinforcing bar ♂
, a to be fitted into the joint grooves d, d of a.

However, since the opening is assumed to be narrow as described above, the backing member i must be fitted over the reinforcing bars d before assembling the reinforcing bars a and a. When assembling, the backing member i
There is a risk of damaging it.

Therefore, in order to solve the above-mentioned difficulties, we have also proposed a backing member (2) as shown in Fig. 6. In this case, the opening n between the reinforcing bars a and a is formed on the free edge of the backing member. As a result, even after the iron #a, a is assembled later, it can be fitted from the outside into a required location and tied to the reinforcing bars a, a with a tie wire (not shown) or the like.

However, no matter which of the backing members shown in FIG. 5 or FIG. There is no problem if ' is relatively narrow, but when it comes to large diameter reinforcing bars,
The ribs protruding from the outer circumferential surface also grow to a certain extent, so the above-mentioned gaps q and q' inevitably become considerably large and shrink, and as a result, the deposited metal melted during welding is The molten metal is washed away from the backing member through the molten metal and drips down, resulting in insufficient welding strength at the joint and the risk of falling molten metal.

(Problems to be Solved by the Invention) Claim (1) has been studied in view of the various difficulties in the welded joint construction method, and breaks down the conventional idea that the backing member is made of metal. Ceramics is selected as the material so that the backing member can be crushed and removed after the welded joint is completed, thereby making it possible to directly visually inspect the joint joint and reliably conduct an external inspection. The first objective is to make the welding process cheaper than steel, steel, or even copper, eliminate the large-diameter parts left behind by the backing member at the joint joint, and enable simple and quick welding work. It is a purpose.

Furthermore, in claim (1) above, the ceramic acid backing member is not only fitted over the reinforcing bars to be welded to perform welding, but also placed in the gap between the backing member and the reinforcing bars in a non-flammable manner. By performing welding after filling with steel, the molten metal at the reinforcing bar joint does not flow and sag.This ensures welding strength and prevents sagging of molten metal. The second purpose is to completely prevent the danger of falling.

Next, in claim (2), a heat-melting material is selected as the non-flammable material in claim (1), so that the molten metal produced by the welding work is non-flammable. This improves the releasability when the backing member is crushed and peeled off, making it easier to remove and clean the backing member, and also prevents the molten metal from solidifying. The purpose is to achieve a smooth surface finish on the weld metal that is formed.

In the welding method of claim (3), in the case of longitudinal reinforcement, when the upper large diameter reinforcing bars and the lower lower small diameter reinforcing bars are used, only the gap formed between the backing member and the lower small diameter reinforcing bars is used. By filling the area with a noncombustible material, the welding strength is effectively increased and the molten metal is prevented from flowing or dripping by providing the noncombustible material at only one location.

(Means for Solving the Problems) In order to achieve the above object, the present invention in claim (1) provides that the first reinforcing bar and the second reinforcing bar to be welded are arranged so that the joining groove portion thereof is The inner circumferential curved surface of the backing body, which is made of ceramic acid and has a notched cylindrical shape, extends over the first and second joint ends of the first and second reinforcing bars in a state where they are connected facing each other with a distance apart. In the fitted state, a notch opening for welding is closed between the opening edges of the backing body, and the inner curved surface of the backing body and one or both of the first and second reinforcing bars are closed. The gap formed between the outer peripheral surfaces is filled with a noncombustible material such as asbestos cloth or glass wool, and a welding tool is inserted through the notch opening to join the first and second reinforcing bars, etc. The present invention seeks to provide a welding method using a backing member for a reinforcing bar joint, characterized in that the backing body made of the ceramic acid is crushed after welding between The content of claim (1) is the adoption of a noncombustible material with heat-melting properties.

Furthermore, in claim (3), the upper first reinforcing bar with a large diameter and the second reinforcing bar with a lower smaller diameter to be welded are arranged so that their joining grooves face each other with a predetermined distance apart. In the state of continuous longitudinal reinforcing bars, the first reinforcing bar in the first and second reinforcing bars is
, a notch opening for welding work is opened between the opening edges of the backing body over the second joint end, with the inner circumferential curved surface of the notched cylindrical backing body made of ceramic acid in a fitted state. At the same time, the gap formed between the inner curved surface of the backing body and the outer circumferential surface of the second reinforcing bar is filled with a noncombustible material such as asbestos cloth or glass wool, and a welding tool is inserted through the notch opening. The method uses a backing member for a reinforcing bar joint, characterized in that the backing body made of ceramics is crushed after welding between the joining grooves of the first and second reinforcing bars, etc. We are trying to provide a welding method.

(Function) In the welding method of claim (1), the first. If the backing body is fitted into the weld joint of the second reinforcing bar and welding is performed through the notch opening of the main body, the welding joint of the first and second reinforcing bars will be The joint grooves each melt and try to flow in a molten metal state using the backing body as a receiving body. Since the gap between the second reinforcing bar and the inner curved surface of the backing body is closed with a noncombustible material, the weld metal does not flow or drip out of the backing body through this gap, and is sufficiently amount to be cleaned between the first and second joint ends,
When this is cooled and solidified, satisfactory welding strength can be obtained.

Next, in claim (2), since the noncombustible material has thermal melting properties, the molten metal generated by performing the welding operation as described above comes into contact with the noncombustible material and melts the surface side of the noncombustible material. After welding is completed.

When crushing and removing the backing body, the nonflammable material and the backing body can be easily separated, and the surface of the molten metal also solidifies in contact with the molten nonflammable material, resulting in a smooth surface. This will allow you to finish the appearance.

Furthermore, in the case of claim (3), the second
Only the reinforcing bars are filled with non-combustible material, but the molten metal from the welding process flows downward as the reinforcing bars are vertical.
Therefore, unwanted flow displacement and dripping of the molten metal are sufficiently prevented.

(Example) The welding method according to the present application will be described in detail with reference to FIGS. 1 to 3. In this method, a backing member l as shown below is used.

This backing body 1δ is made of ceramic and is formed into a notched cylindrical shape having a desired wall thickness and a cross section approximately in the shape of a horseshoe, and has a predetermined length L.

In other words, the backing main body 1a has a shape in which a notch opening 1b is opened by cutting out a portion of a cylindrical pipe in the longitudinal direction, and the notch opening 1b is opened in the figure.
are the inner and outer curved surfaces of the backing body 1a, respectively,
Further, le and le indicate the opening edge portions of the main body 1a.

For the illustrated backing body 1a, its notch opening 1b
If it is made larger than the diameter of the first and second reinforcing bars A and A', even after the reinforcing bars A and A' have been installed, it will be possible to fit the reinforcing bars A and A' from the outside as described below. However, the cutout opening 1b is located between the first and second reinforcing bars A,
If the diameter is smaller than ＾°, it must be fitted over the reinforcing bars in advance.

In addition, the backing body 1a may not be integrally formed as in the above embodiment, but may be constructed by connecting a pair of halves with a hinge. , the reinforcing bars can be fitted even after installation is completed, and the notch opening can be formed sufficiently small when the half body is closed, so that the molten metal generated during welding drips from the edge of the opening as described later. It is also desirable to be able to prevent this.

Using the backing member l as described above, the inner circumferential curved surface IC of the backing body 1a is connected to the first and second reinforcing bars A.

The backing member l is fitted over the first and second joint ends At, A; at A', but in order to maintain this state, the backing member L is fitted using a binding wire (not shown) as is known in the art. It will be necessary to tie it to the first and second reinforcing bars A and A' or use other supporting devices.
The reinforcing bars ^, A' have joint grooves A2, A2' facing each other with a predetermined distance apart, and a notch between the opening edges 1e, le of the backing body 1a is formed. From the opening 1b, the above joint grooves A2, A? To be able to perform welding work at the same time.

Now, when the backing body 1a is fitted over the first and second reinforcing bars A and A' as described above, in the case of FIG. 1 according to claim (3), the first reinforcing bar A is formed with a large diameter at the top, and the second reinforcing bar A' is formed at a small diameter at the bottom, so that
In the case of such vertical bars, a gap G will be created between the first and second reinforcing bars A, A' and the inner circumferential curved surface 1c of the backing body 1a. While the gap is relatively small, the gap with the second reinforcing bar A' becomes quite large.

In such a case, in the welding method of claim (3),
The gap G on the second reinforcing bar A° side is filled with the noncombustible material 2.

Here, as the noncombustible material 2, asbestos cloth, glass wool, etc. can be used, and these noncombustible materials 2 are defined in claim (2).
As shown in the welding method, it is best to select a material that has thermal melting properties.

In practice, in order to apply this noncombustible material 2, it is necessary to apply the noncombustible material 2 to the joint end A of the second reinforcing bar A! It is preferable to wrap the backing main body 1a from the outside.

On the other hand, in the case of FIGS. 2 and 3 according to claim (1), even if the first and second reinforcing bars A, A
A non-combustible material 2 is filled in one or both of the gaps G between the backing body 1a and the backing body 1a.In the case shown in FIG. Even if the outer diameter is the same, the distance between the joint grooves A2 and A2' is large (for example, 15 to 20 cm), and in such a case, the capacity of the molten metal will also be large. This makes it easier for the molten metal to flow and drip, but
Filling with the above-mentioned non-combustible material 2 completely prevents this.

In addition, Fig. 3 shows a case where the first and second reinforcing bars A and A' are thick as described above, and as a result, the gap G becomes large (for example, 4 or more gaps). Even in such a case, the noncombustible material placed in the gap G effectively prevents the flow of molten metal during welding.

It can prevent dripping.

Furthermore, as shown in claim (2) above, when the noncombustible material 2 is given thermal melting properties, the molten metal during welding will melt the surface of the noncombustible material 2. from,
After the molten metal is solidified, the peelability between the backing body 1a and the noncombustible material 2 becomes good, and the surface shape of the welded metal becomes smooth.

(Effect of the invention) Since the present invention is implemented as described above, in the case according to claim (1), the noncombustible material filled in the gap prevents the molten metal from flowing or dripping. This allows welding of sufficient strength to be easily performed without the risk of dripping of molten metal.

Furthermore, according to claim (2), since the noncombustible material has thermal melting properties, the crushing and removal work of the backing member and the cleaning work can be easily performed due to improved peelability, and the weld metal can be easily removed. The surface can also be finished smooth.

In addition, according to claim (3), only the gaps in the lower small-diameter reinforcing bars that are vertical bars are filled with noncombustible material,
Unintentional dripping of molten metal can be prevented.

[Brief explanation of drawings]

Figures 1 (a) and (b) are a perspective view and a longitudinal sectional front view of a welded joint showing the welding method according to claim (1), respectively, and Figure 2 is a welding diagram showing the welding method according to claim (1). 3(a) and 3(b) are cross-sectional plan views of the joint portion, and FIG. b) is a front explanatory view and a right side end view of a welded joint showing a conventional method of welding a reinforcing joint with a backing member, and FIGS. A side view, a right side view, and a plan view of a welded joint portion showing the welding method, and FIG. 6 is a plan view of the same according to another previously proposed example. la...Backing body 1b...Notch opening 1c...Inner peripheral curved surface le...Opening edge 2...Noncombustible material A ...First reinforcing bar Ao...Second reinforcing bar...First joint end...Second joint end...・First joint groove section...Second joint groove section...Gap

Claims (3)

[Claims] (1) The first reinforcing bar and the second reinforcing bar to be welded are in a state where their joining grooves are facing each other with a predetermined distance apart, and the first and second reinforcing bars are 1st, 2nd
The inner curved surface of a notched cylindrical backing body made of ceramic is fitted over the joint end of the backing body, and a notch opening for welding is closed between the opening edges of the backing body. A gap formed between the inner curved surface of the backing body and the outer circumferential surface of one or both of the first and second reinforcing bars is filled with a noncombustible material such as asbestos cloth or glass wool, and the notch opening is filled with a noncombustible material such as asbestos cloth or glass wool. After inserting the welding tool from the part and welding between the joint groove parts of the first and second reinforcing bars, etc.,
A welding method using a backing member for a reinforcing bar joint, characterized in that the backing body made of ceramics is crushed. (2) A welding method using the backing member for a reinforcing bar joint according to claim (1), wherein the noncombustible material has thermal meltability. (3) The upper first reinforcing bar with a large diameter and the second reinforcing bar with a lower small diameter to be welded are in a vertical reinforcement state in which the joining grooves are connected facing each other with a predetermined distance apart. and across the first and second joint ends of the first and second reinforcing bars,
The inner circumferential curved surface of the backing body, which is made of ceramic and has a notched cylindrical shape, is fitted, and a notch opening for welding work is formed between the opening edges of the backing body, and
A gap formed between the inner curved surface of the backing body and the outer circumferential surface of the second reinforcing bar is filled with a noncombustible material such as asbestos cloth or glass wool, and a welding tool is inserted through the notch opening. , a welding method using a backing member for a reinforcing bar joint, characterized in that after welding between the joining grooves of the first and second reinforcing bars, the backing body made of ceramics is crushed. .