JPH0761541B2 - Enclosed arc welding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an enclosed arc welding device for performing enclosed welding with a rod-shaped material to be welded such as a reinforcing bar standing vertically.

[Prior Art] In the conventional closed arc welding in the case of a vertical joint, a so-called diagonal I-shaped groove was processed (Japanese Patent Publication No. 52-35624). FIG. 6 is a side view showing an enclosed arc welding device in the case of a conventional vertical joint, and FIG. 7 is its side view.
FIG. 7 is a sectional view taken along line VII-VII. In this welding process, for example, the deformed rebar 1 is provided with its joint surface inclined with respect to its axial direction, and the two rebars 1 are arranged vertically with a predetermined open space provided therebetween. , A pair of split copper metal plates 2 are arranged so as to surround the groove space. And
The welding rod 3 is inserted into the groove space from the welding port 4 of the copper dowel 2 provided on the upper side of the groove space, and the weld metal is filled from the lower part to the upper part of the groove space. As a result, the fixed vertical workpieces can be quickly and soundly joined.

In recent years, as a method of joining reinforcing bars embedded in concrete columns of reinforced concrete buildings, they must be assembled by the pre-assembly method in order to improve the efficiency of the method of joining one piece at a construction site. Is increasing. In other words, in the factory or on the ground, multiple rebars are assembled in advance, they are stacked at the construction site, and the assembled assemblies are welded in a horizontal position. It is used for things.

Since the above-mentioned enclosed arc welding has the advantages that the shape of the joined joint does not become excessively large and the workability of the hoop reinforcement, which is a post-process, is good, the enclosed arc welding technology is used for this pre-assembly method. Has been done.

[Problems to be Solved by the Invention] However, the conventional enclosed arc welding technique is
Since the weld groove has an oblique I shape, it has the following drawbacks. That is, in the case of this oblique I-shaped groove, there is a constraint that welding must be performed by inserting a welding rod into the groove from above in the extension direction of the groove surface. For this reason, in the pre-assembled rebar construction method, it is necessary to pre-assemble the rebar so that the groove will be in that direction in consideration of the direction of welding work in advance. In consideration of the welding process direction, it is necessary to process the inclined joint surfaces so that they are parallel to each other.

For this reason, it is necessary to strictly control the direction of the reinforcing bars during pre-assembly, and despite the fact that the pre-assembly method is adopted for the purpose of speeding up and improving efficiency, the work is actually extremely complicated and inefficient. There is a problem that is.

In addition, inclining the joining surface of the reinforcing bar with respect to the axis, the process is complicated and the amount of cutting is increased,
There is a problem that the yield decreases. Furthermore, when this groove processing is performed by gas cutting on site, gas notches are likely to occur, and there is a disadvantage that much labor is consumed in the grinder grinding work of the groove surface (bonding surface).

The present invention has been made in view of such problems,
It is an object of the present invention to provide an enclosed arc welding device that can easily process the joining surface of the groove, shortens the groove processing time, and has no restrictions on the tip assembly and can perform the tip assembly quickly and easily. To aim.

[Means for Solving the Problems] An enclosed arc welding device according to the present invention has a rod-like shape, and a pair of materials to be welded, the joining surfaces of which are substantially perpendicular to the axial direction, are provided between the joining surfaces. In an enclosed arc welding apparatus that arranges a predetermined groove space and arranges it vertically, and performs arc welding between the joint surfaces, one of the joints including the groove space and the joint surfaces of the upper and lower workpieces. A copper metal having an opening at the finishing end on the front side that covers the portion and the side surface of the lower material to be welded behind the opening and a predetermined gap is provided between the upper material to be welded. And a pressing member which is provided and surrounds a part of the groove space, and a pressing unit which is attached to the copper metal plate behind the opening and presses the metal member toward the lower material to be welded. It is characterized by

In addition, the joint surface is substantially perpendicular to the axial direction of the rod-shaped material to be welded, when performing welding according to the invention of the present application, an inclination of a degree that limits the attachment position of the material and the insertion position of the molten material. It means not having, in other words, an inclination that does not cause a problem even if the directionality of welding is not considered in construction.

Further, when this material is overlapped on the side surface of the material to be welded below, it is not necessary to contact this material with the material to be welded over the entire area of the overlapped material, and contact is made with a part of that area. Just do it. Further, it is needless to say that this material does not need to contact the entire side surface of the material to be welded below.

[Operation] In the present invention, a horizontal groove is provided, and the material is placed in contact with the side surface of the lower member to be welded. This material surrounds a part of the groove space and is arranged with a predetermined gap between it and the material to be welded above. Further, a part of the joint including the groove space and the upper and lower joint surfaces of the material to be welded is covered with a copper metal having an opening on the side where the material is not disposed. Then, the pressing member presses the material toward the material to be welded therebelow.

After arranging the material and the copper metal in this way, welding means such as a welding rod is inserted into the groove space through the opening, and arc welding is performed between the joint surfaces. First, for example, a bridging portion is formed by pouring molten metal from the lower side of the material to be welded near the material.

In this case, since the material is disposed on the far side of the groove space, the end of the joint surface of the materials to be welded does not burn through at the start of welding. Further, by using this material, a bridging portion can be easily provided between the joint surfaces of the upper and lower materials to be welded. Furthermore, since the slag floats upward and is discharged from the gap formed between this material and the material to be welded above, the slag does not remain in the welded portion between the joint surfaces. Furthermore, except for the opening, the side of the material to be welded is covered with copper metal, so even if a high current is constantly applied and welding is performed at a high speed during the welding period, the molten metal will burn through. There is no. The appearance of the welded part after welding is also beautifully finished.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side sectional view showing an enclosed arc welding apparatus according to an embodiment of the present invention, FIG. 2 is a horizontal sectional view of the same, and FIGS. 3 (a) to 3 (e) are schematic diagrams showing its operation. Is.

The upper reinforcing bar 11 and the lower reinforcing bar 12 have their joint surfaces substantially perpendicular to the axial direction. Therefore, when the reinforcing bars 11 and 12 are arranged vertically with their axial directions aligned, both joint surfaces are Are substantially horizontal and parallel to each other.

A copper plate 14 made of copper or a copper alloy has a U-shaped horizontal cross section, and a groove space 15 formed between the upper reinforcing bar 11 and the lower reinforcing bar 12.
It is arranged so as to hold the joint portion including the joint surface of the reinforcing bars 11 and 12 with the center being as the center. This copper metal 14 has its inner surface and rebar
There is a slight gap between the peripheral surfaces of the joints 11 and 12. In order to provide a predetermined groove gap between the joint surfaces of the reinforcing bars 11 and 12, a scale 22 is engraved with a notch having the same length as this groove gap at one end of the U-shape of the copper plate 14. ing.

A clamper 30 is fixed to each of the upper end surface and the lower end surface of the copper plate 14. This clamper 30 is composed of half-clamped clamp members 31 and 32 each having a semicircular notch so as to be rotatable relative to each other around a vertical axis at their base ends, and one clamp member 31 is a copper plate. It is fixed at 14. When the clamp members 31 and 32 are combined and integrated, the rebar 11,
A circular hole with a diameter approximately equal to 12 is formed. The screw rod 34 is attached to the tip of the clamp member 31 so as to be rotatable around a vertical axis, and the handle 33 is screwed into the screw rod 34. On the other hand, a recess (not shown) in which the screw rod 34 can be engaged is formed at the tip of the clamp member 32.

Behind the groove space 15 between the reinforcing bars 11 and 12, there is a recess 16 in the copper plate 14
Is formed, and the material 13 is disposed in the recess 16 in contact with the side peripheral surface on the back side of the lower reinforcing bar 12. The strip 13 is pressed and fixed to the lower rebar 12 from behind by a bolt 17 that penetrates the copper strip 14 in the horizontal direction. This material
When 13 is made of metal, it is joined to the welded portion after the welding is completed and becomes a part of the joint, and it is not necessary to remove the material 13 after the construction, so the work is simplified. On the other hand, if a refractory material is used as the material 13, a back bead is formed and the appearance is adjusted,
Since this material 13 is removed after the construction, the joint performance can be judged by observing the appearance of the welded portion.

Next, the operation of the apparatus thus configured will be described. First, in a state where the material 13 is housed in the recess 16 of the copper metal 14, the reinforcing bars 11 and 12 are formed in the semicircular notches of the pair of clamp members 31.
Are fitted and the pair of clamp members 32 are rotated to be aligned with the clamp members 31, respectively, and the reinforcing bars 11 and 12 are surrounded by the clamp members 31 and 32. Then, the screw rod 34 is rotated to engage with the recess of the tip of the clamp member 32, the handle 33 is rotated to advance the handle 33 toward the tip of the clamp member 31, and the handle 33 and the clamp member 31 are moved. The tip of the clamp member 32 is clamped and tightened between the tip and the tip. This allows
Both the reinforcing bars 11 and 12 are gripped by a pair of clampers 30 so that the axes of the reinforcing bars 11 and 12 coincide with each other.
It is disposed so as to face vertically with the clamper 14 and the clamper 30 interposed therebetween.
The groove spacing between the joint surfaces of the reinforcing bars 11 and 12 may be adjusted with reference to the scale 22 provided at the tip of the copper plate 14.

After arranging the upper rebar 11, the lower rebar 12, the bar 13 and the copper plate 14 in this way, as shown in FIG.
Insert 18 into the groove space 15 from the U-shaped open side of the copper dowel 14,
Welding is started from the vicinity of the material 13 (back side of the groove space 15). That is, first, the material 13 on the joint surface of the lower rebar 12 is
Start the arc at a position of 5 to 6 mm before, and immediately move the arc to the corner part between the joint surface of the lower reinforcing bar 12 and the material 13 and weave it while shortening the arc to melt the molten metal. Wait for excitement.

Then, as shown in FIG. 3 (b), the molten metal 20 is applied to the material.
It is piled up on the joint surface of the lower reinforcing bar 12 by using 13, and in this case, the generated slag 21 floats on the molten metal 20. Then, the joining surface (upper groove) of the upper rebar 11 and the molten metal
When the distance from 20 becomes 2 to 3 mm, weaving is stopped and the arc is stopped to melt the corner of the upper groove,
To bridge.

After bridging the upper rebar 11 and the lower rebar 12, as shown in FIG. 3 (c), the generated slag is utilized by utilizing the gap between the upper rebar 11 and the bar 13 while weaving. While discharging to the outside of the groove, the welding rods 18 are alternately turned upward and downward to secure the penetration between the upper groove side and the lower groove side. In this way, as shown in FIGS. 3 (d) and 3 (e), the molten metal 20 is continuously laminated up to the foremost part of the groove.

In addition, in the forefront part (end part on the finishing side) of the lower reinforcing bar 12, it is preferable that the interruption and formation of the arc be repeated to raise the deposited metal while cooling it. When continuously welded, so-called overlap occurs in the lower rebar 12 and the upper rebar
Undercut is likely to occur in 11.

Next, the arc is stopped, the molten metal 20 is cooled and solidified, and then the clamper 30 is removed to complete the welding.

In the present embodiment, the lower reinforcing bar 12 side is contacted with a small piece of the supporting bar 13 in the inner part of the copper plate 14 so that the upper reinforcing bar 11 and the lower reinforcing bar are
Allows bridging of weld metal 20 with 12. And the upper rebar
The I-shaped groove formed at the joint surface between 11 and the lower reinforcing bar 12 is laterally arc-welded. If welding is performed without using the material 13, proper bridging between the upper reinforcing bar 11 and the lower reinforcing bar 12 is not formed in the inner part of the I-shaped groove. Because of the welding posture, the molten metal 20 only spreads on the groove surface (joint surface) of the lower rebar 12 and does not easily reach the upper rebar 11. In this way, the piece of material 13
Has a function of depositing the molten metal 20 in the deep part of the groove and promoting bridging between the upper and lower rebars.

Further, in the present implementation decree, as described above, the copper material 14 is provided on the sides of the groove space 15 as well as on the back side of the groove space 15. Therefore, the molten metal 20 is reliably prevented from being welded, so that the welding current can be made high throughout the entire welding period and high-speed welding can be performed. Bronze
If 14 is not used, it is necessary to reduce the current in order to prevent burn-through when welding the peripheral portions of the joint surfaces of the reinforcing bars 11 and 12.
As described above, the use of the copper alloy 14 facilitates the welding work.

Further, the copper of the copper plating 14 or the copper plating has the property of not getting wet with the molten metal 20, and there is a slight gap between the inner peripheral surface of the copper plating 14 and the groove space 15. The back bead is formed in this gap portion, and the welded portion surrounded by the copper metal plate 14 is formed to have a beautiful appearance.

In this welding process, as indicated by arrow 22 in FIG. 4, the arc is horizontally swung to perform weeping. That is, first, weaving is started from the fillet portion between the material 13 and the joining surface of the lower reinforcing bar 12, and while the arc is swung in the left and right direction, the arc is made to the finishing side end portion (the groove frontmost portion) on the front side. To move.

By carrying out such weaving to raise the molten metal on the joint surface, the entire joint surface is uniformly kept at a high temperature, slag entrapment is prevented, and the work for removing the slag becomes unnecessary. Therefore, it is possible to perform the welding operation substantially continuously. If you do not weave continuously and cut the arc in the middle, you need to remove the slag. When the base material is cooled to room temperature during slag removal work, it is necessary to heat it to 250 ° C or higher and restart welding.

In the initial stage of the welding process, the arc is swung to the left and right, but in the middle period, it is preferable to swirl the arc in the left and right directions and to add weaving with small amplitude in the up and down directions. This facilitates creation of the bridging portion, facilitates discharge of slag through the gap between the bar 13 and the upper reinforcing bar 11, and reliably prevents slag entrapment.

Further, by carrying out the weaving, it is possible to form an appropriate so-called back-wavy bead on the side surface of the joint, and at the end on the front side on the finish side, it is necessary to take special measures to prevent burn-through of molten metal. Disappear.

As described above, in order to form the bridging using the bar 13, the both ends of the lower bar 12 of the bar 13 in the circumferential direction are rebar.
The central angle θ with the axis of 12 must be 30 ° or more. However, if this material is too large, it will be difficult to discharge the slag 21 during the enclosed arc welding out of the groove, and it is easy to cause welding defects such as large-scale slag entrainment and fusion failure resulting from this. Become. For this reason, this material 13 has a center angle θ of about 150 (150/3) of the circumference of the rebars 11 and 12 to be welded.
Stop so that it covers an area of 60) ° or less.

The distance d (mm) between the upper reinforcing bar 11 and the material 13 is 2 to D /
It is preferably 2 mm. However, D (mm) is the upper rebar 11
And the lower rebar 12 is the distance. When d is less than 2 mm, the escape of the slag 21 becomes poor and the slag is apt to be caught. Moreover, in order to discharge the slag 21, a high degree of skill and strict monitoring of welding conditions are required. On the other hand, d is
If it exceeds D / 2, it is difficult to form a bridging portion by the molten metal 20. Therefore, the joint is not completed.

Incidentally, in welding, the inner peripheral surface of the material 13 and the outer peripheral surface of the rebar 12 are curved with the same curvature, and the material 13 is in full contact with the rebar 12 within the range of the central angle θ described above. Is ideal. However, as shown in FIG. 5 (a), the case where the diameter of the lower reinforcing bar 12 is large and a gap a is formed between the central portion of the bar 13 and the reinforcing bar 12, and FIG. 5 (b). In some cases, the lower rebar 12 has a small diameter, and both ends of the bar 13 are separated from the peripheral surface of the rebar 12 by a distance b as shown in FIG. Also in this case, if a is about 2 mm or less and b is 2 to 3 mm, the same effect as contacting the lower reinforcing bar 12 on the entire surface of the material 13 can be obtained. As a result, a dedicated material for each rebar with different cross-sectional diameter
The complexity of preparing 13 can be avoided.

Further, it is preferable that the groove interval defined by the joint surfaces of the upper and lower reinforcing bars 11 and 12 is set according to the diameter of the reinforcing bars 11 and 12. If the groove interval is too narrow, it may be difficult to operate the rod, which may cause poor penetration and slag inclusion.Therefore, loosen the clamper 30 to separate the reinforcing bars 11 and 12, or rework the joint surface of the reinforcing bar. By doing so, the groove space is made appropriate. On the other hand, if the groove interval is too wide, the consumption of the welding rod increases and the welding time increases, which is uneconomical.

In order to properly maintain this groove interval, it is sufficient to form a notch or the like in the copper metal 14 and provide the scale 22 as described above, and use this scale 22 to adjust the groove interval. This streamlines work. However, it is also possible to adjust the groove spacing by using a standard spacing gauge and inserting this standard spacing gauge between the mating surfaces.

If the eccentricity between the reinforcing bars 11 and 12 is too large, it becomes difficult to mount the jig, and causes undercut and overlap. Therefore, when the eccentricity exceeds 1/10 of the nominal diameter of the reinforcing bars 11 and 12, it is preferable to mount the welding jig in combination with a reinforcing bar clamp adjuster or the like.

On the other hand, when the reinforcing bars to be joined are mutually restrained, an appropriate correction means such as a bender is taken to keep the displacement between the joined surfaces within a predetermined range.

It should be noted that it is preferable to remove deposits such as oil / fat, paint, concrete mist, or severe rust on the groove portion, which adversely affect welding by using a wire brush or grinding.

Also, welding can be performed by a construction method using a welding means other than the covered arc welding rod depending on the purpose of construction. For example, in order to make the work even more efficient, if consumable electrode-fed gas shielded arc welding is used, the welding time is about 1/2 to 1/3 that of covered arc welding due to its electrode wire melting characteristics. It is possible to However, it is needless to say that it is necessary to provide an appropriate windproof means to create a perfect shield state.

Further, the shape of the material 13 is, as in the above embodiment, the reinforcing bars 11, 12
The contact surface with respect to is curved and has a recess, and the back surface thereof is not limited to a flat surface, but may be curved with a constant thickness, for example, by cutting a part of a cylinder.

Next, the result of the vertical welding of the I-groove actually carried out by the apparatus of the embodiment of the present invention will be described.

Used reinforcing bar; SD35, SD40 (JIS) Reinforcing bar shape; JIS G3112 (Steel bar for reinforced concrete) Reinforcing bar diameter; D21 and D38 Welding bar; For SD35, use JISD5816 For SD40, use JISD7016 For groove spacing; D22 In case of 10mm and 14mm, in case of D38 it is 12mm
And 16 mm material; width 25 mm, length 20 mm, thickness 10 mm SM41 material (JIS) Welding current; D38: 150 to 170 A, D22: 120 to 130 A When welding under these welding conditions The characteristics of the obtained welds are shown in Table 1 below.

Both have sufficient strength and ductility.

Further, Table 2 below shows the welding results of the case where the reinforcing bars having a diameter of D41 are used for welding according to the embodiment of the present invention and the case where welding is performed according to the conventional example, by comparing the two.

As is clear from Table 2, according to the present embodiment, the required time is approximately halved as compared with the conventional example, and the efficiency is extremely high.

Further, as described above, since the joining surface can be horizontal and the enclosed arc welding can be performed, when the rebar is pre-assembled,
It is not necessary to assemble the reinforcing bar in consideration of its directionality, and therefore, it is possible to quickly assemble the rebars, and the advantages of the preassembly method can be fully utilized. Further, since it is sufficient to form a joint surface substantially perpendicular to the axial direction of the reinforcing bar, it is easy to form a groove shape and the yield is high because there are few cut-off portions.

EFFECTS OF THE INVENTION According to the present invention, there is an advantage that the groove shape is an I-shape which is perpendicular to the axial direction of the material to be welded and there is no restriction on the directionality with respect to the axis of the material to be welded to be constructed. . Further, since the groove is perpendicular to the axis of the material to be welded, it can be used as it is, for example, as obtained from the reinforcing bar, or as it is at high speed cutting or gas cutting, and the processing is simple.

Further, it is not necessary to remove the slag until the end of welding, and the groove area is reduced to 70% of the conventional one, so that welding can be performed with even higher efficiency.

Furthermore, since the lateral side portion of the material to be welded is covered with the copper metal, it is possible to reliably prevent the molten metal from being burned down, and it is possible to speed up the welding due to the high current,
In addition, the appearance of the welded part will be beautiful.

Furthermore, it is not necessary to draw the rebars to be joined together, and it is possible to construct a joint for the restrained rebars.

As a result, according to the present invention, the work at the construction site can be made highly efficient, and welding can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a side view showing an enclosed arc welding apparatus according to an embodiment of the present invention, FIG. 2 is a horizontal sectional view of the same, and FIGS. 3 (a) to 3 (e) are schematic views showing this operation. Fig. 4 is a schematic diagram showing the weaving method, Fig. 5 (a),
(B) is a plane sectional view of a reinforcing bar, FIG. 6 is a side view showing a conventional apparatus, and FIG. 7 is a sectional view taken along line VII-VII of FIG. 11,12; Reinforcing bar, 13; Material, 14; Copper metal, 15; Groove space, 30; Clamp.

Claims (7)

[Claims] 1. A pair of materials to be welded, each of which has a rod-like shape and whose joint surface is substantially perpendicular to its axial direction, is vertically arranged with a predetermined groove space provided between the joint surfaces, In an enclosed arc welding apparatus for arc welding between surfaces, a copper having an opening at a finishing end on the front side which partially covers a joint portion including the groove space and joint surfaces of upper and lower workpieces. A metal contacting the side surface of the lower material to be welded behind the opening and the upper material to be welded behind the opening and surrounding a part of the groove space with a predetermined gap. An enclosing arc welding apparatus, comprising: a material; and a pressing unit that is attached to the copper metal plate behind the opening and presses the material toward a lower material to be welded. 2. The enclosure according to claim 1, further comprising clampers which are provided at an upper end and / or a lower end of the copper plate and are capable of clamping the upper and / or lower workpieces, respectively. Arc welding equipment. 3. The copper metal block has a storage part for storing the metal plate, and the pressing means is disposed in the storage part and an operating mechanism arranged outside the copper metal plate of the storage part. The enclosing arc welding device according to claim 1 or 2, further comprising a pressing mechanism that is installed and operates by the operating mechanism to press the material against the material to be welded. 4. The pressing mechanism is a threaded rod screwed into the copper metal, and the operating mechanism is a screw fixed to an end of the threaded rod outside the housing. The enclosed arc welding device according to any one of 1 to 3. 5. A predetermined gap is provided between the inner surface of the copper metal and the material to be welded.
The enclosed arc welding device according to any one of 1. 6. A gap between the material and the upper material to be welded is
It is 2 mm or more, and is 1/2 or less of the distance between the joint surfaces of the upper and lower welded materials.
The enclosure arc welding device according to any one of claims 1 to 5. 7. The material according to claim 1, wherein the material is in contact with the axial center of the lower material to be welded in a region having a central angle of 30 to 150 °. The enclosed arc welding device described in.