JP2721664B2 - Welding method and welding device between pipe-shaped metal base materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for welding between pipe-shaped metal base materials for effectively welding and connecting the pipe-shaped metal base materials.

[0002]

2. Description of the Related Art In general, welding is well known as one method of joining metals. A conventional welding method will be described by taking a normal arc welding as an example. As shown in FIG. 30 (a), for example, a metal base material 1 or 2 to be welded is formed by forming a V-shaped or U-shaped groove 3 on a metal base material. The ends of the base materials 1 and 2 are processed, and the interior of the base materials 1 and 2 is filled with a weld metal to melt the surfaces of the metal base materials 1 and 2 to form a weld seam 4 together with the weld metal. , 2
To join. Here, when the weld seam 4 is formed, a part of the weld metal easily flows out of the route 5 or the weld metal is not easily filled in the route 5. In addition to welding from the front surface of the material, the back surface welding of the metal base material is performed.

[0003] In backside welding, the deposited metal is route 5
30B or when the weld metal is not filled in the route 5, as shown in FIG. 30 (b), grinding and gouging are performed.
After forming the groove 6 by removing the weld metal so that the shape becomes constant, as shown in FIG. 30C, a re-welding operation for further filling the groove 6 with the weld metal is performed. As described above, in a conventional series of welding operations, welding has to be performed from both the front side and the back side of the metal base material, and the welding process is accordingly complicated.

[0004] Therefore, as an improvement method for eliminating the above-mentioned disadvantages, Korean Utility Model Publication No. 80-1183 has been proposed.
Nos. 80-221, 83-1085, and U.S. Pat. Nos. 3,929,270 and 3,548,489 disclose a method of supporting a back surface of a metal base material which is abutted during welding.

[0005] As shown in FIG.
The gap 8 is formed so that a constant bead is formed on the bottom surface of the route 5 formed by the butted metal base materials 1 and 2.
In this method, the backing such as the refractory material 9 having the refractory particles having the formed refractory particles is bonded to the metal base materials 1 and 2 by using an auxiliary tape 10 or the like to perform welding.

According to such a welding method, even if the weld metal flows out of the route 5, the gap 8 of the refractory material 9 is filled with the weld metal. , And it is not necessary to perform welding from both sides as described above, and the welding process can be simplified.

[0007]

However, such a method is effective when the metal base materials 1 and 2 are flat plates, but when welding a cylindrical metal base material such as a pipe, A space is easily formed between the refractory material 9 and the metal base material,
Moreover, the refractory member 9 is provided inside the pipe along its inner peripheral surface.
However, it is difficult to provide a backing as described above, so that it is not suitable for practical use.

Therefore, when welding a pipe-shaped metal base material, it is only possible to perform welding from the outer surface of the pipe, and it is impossible to perform processing such as backing on the back surface (the inner surface of the pipe). It is only possible to remove irregularly shaped protrusions caused by the flow of the deposited metal caused by welding, only at the back surface of the weld, which can be observed from the outside of the pipe and where a grinder can be used. Did not.

Therefore, in order to solve such a problem,
Korean Patent Publication No. 94-11512 discloses a method and an apparatus for welding a pipe-shaped metal base material. This welding method uses a pipe-shaped metal base material with different polarities
This is a method in which the electrodes are brought into close contact with each other while generating an arc by approaching each other.

According to this method, there is an advantage that the pipe base material can be joined without forming a bead at the welding portion. However, it is necessary to allow currents of different polarities to flow through the pipe base material itself to be joined. In addition, it is necessary to fix the pipe base material, and therefore, it is necessary to use hydraulic equipment and the very complicated equipment that constitutes it. Not only was this impossible, but it was too costly to use.

SUMMARY OF THE INVENTION The present invention has been made to fundamentally solve the above-mentioned problems, and uses a welding support device which can be easily installed and removed between pipe base materials to be joined. By holding the weld metal formed at the time of welding between the pipe base materials, it is possible to prevent contact with oxygen to prevent oxidation and prevent the weld metal from flowing into the pipe base material. A pipe capable of forming a backside welded state and, if necessary, forming a back bead (back bead) so that even in the case of TIG welding, the pipe can be welded without having to replace the inside with an inert gas. It is an object of the present invention to provide a welding method and a welding apparatus between metal base materials.

[0012]

According to the present invention, there is provided a method and apparatus for welding a pipe-shaped metal base material according to the present invention, wherein a center groove is arranged in a longitudinal direction and a concave groove for forming a back bead is formed as necessary. A trapezoidal block and a reverse trapezoidal block are alternately provided so that the inclined side surfaces of the forward / reverse trapezoidal block are in contact with each other, and these are connected by wires. A heat-insulating band layer obtained by sewing a heat-resistant band piece on the band is provided on expansion means capable of injecting and discharging air, and welding is performed.

More specifically, the heat insulating band layer is provided along the circumferential direction on the outer peripheral surface of the central portion of the expanding means, and the forward and reverse trapezoidal blocks are shifted from each other along the circumferential direction at the center of the heat insulating band. Thus, a group of support blocks for backside welding is provided.

At this time, the size of the outer periphery formed by the welding back surface support block group should be smaller than the inner periphery of the pipe base material to be welded.

In such a state, when the expansion means expands due to the injection of air, the trapezoidal block and the inverted trapezoidal block of the group of welding backside support blocks slide in the respective side surfaces, and the groove of the trapezoidal shaped block and the inverted trapezoidal block. The concave groove of the block communicates with the groove, and the concave groove coincides with the bottom surface of the route formed by abutting the pipe base materials.

In this state, when air is injected into the expanding means to expand the expanding means, the forward / reverse trapezoidal blocks slide on each other's side, and the welding back support blocks are formed in a ring shape on the outer peripheral surface of the expanding means. The pipes come into close contact with the inner peripheral surface of the pipe base material while maintaining the same, and the groove between the welding back-side support blocks and the route between the pipe base materials match. The metal does not flow into the inside of the pipe base material, so that a favorable back welding state can be maintained by the group of the welding back support blocks, and a back bead having a predetermined shape can be formed as necessary.

That is, in the method for welding a pipe-shaped metal base material according to the present invention, a regular trapezoidal block and a reverse trapezoidal block are provided so as to contact alternately inclined side surfaces, and the regular trapezoidal block and the reverse trapezoidal block are connected by a wire. A heat-insulating band layer obtained by sewing a large number of heat-insulating band pieces on a band is provided on the outer peripheral surface of an expansion means capable of injecting and discharging air, on the inner surface of the welding rear-surface supporting block group and the inner surface of the welding rear-surface supporting block group. Injecting air into the expanding means, inflating the expanding means, and sliding the normal trapezoidal block and the inverted trapezoidal block on each other's inclined side surfaces so that the outer peripheral surface of the welding back surface support block group has an inner peripheral surface between the pipe base materials. Surface is pressed, and the pipe base material is welded so that the position of the route between the center of the welding back support block group and the pipe base material coincides with each other. And it features.

Further, in the method for welding between pipe-shaped metal base materials according to the present invention, preferably, a flexible adhesive tape is provided on the inner surface of the group of the welding back support blocks, and air is injected into the inside of the expanding means. The expansion tape is expanded so that the adhesive tape surrounds the welded backing support block group in a state where the position of the route between the pipe base materials coincides with the center of the welded backing support block group. After fixing the welding back surface support block group by bonding to the peripheral surface, the expanding means is isolated from the welding portion of the pipe base material,
Thereafter, the pipe base material is welded.

Further, in the method of welding between pipe-shaped metal base materials according to the present invention, preferably, a back bead can be formed by a concave groove formed in a central portion longitudinal direction of the forward / reverse trapezoidal block. Features.

Further, according to the welding apparatus for a pipe-shaped metal base material of the present invention, an expanding means of a predetermined size capable of adjusting the injection or discharge of air, and a plurality of heat-resistant bands are arranged so that the ends of the heat-resistant bands overlap with each other. A fixed heat-insulating hand layer, a regular trapezoidal block and a reverse trapezoidal block each having a groove formed in the central portion longitudinal direction are alternately provided, and these are connected by wires and the inclined side surfaces of the regular trapezoidal block. The reverse trapezoid block is provided with a group of welded back support blocks that are slidable in a state where the inverted inclined side surfaces are in contact with each other.

Further, the welding device for a pipe-shaped metal base material according to the present invention is preferably characterized in that the inclined portion of the forward / reverse trapezoidal block is formed with an uneven portion which can be fitted to each other.

Preferably, the welding device between pipe-shaped metal base materials according to the present invention has a curved surface formed so that an outer peripheral surface of the forward / reverse trapezoidal block conforms to an inner peripheral surface of the pipe base material. It is characterized by having.

Further, the welding device between pipe-shaped metal base materials according to the present invention is preferably such that the forward / reverse trapezoidal block has
It is characterized in that a taper is provided at a longitudinal edge of the outer peripheral surface so as to have a predetermined angle.

In the welding apparatus for a pipe-shaped metal base material according to the present invention, preferably, the outer diameter of the welding back surface support block group is such that the forward / reverse trapezoidal shape is formed according to the inner diameter of the pipe base material. It is characterized in that it can be adjusted by adjusting the size and number of blocks.

In the welding apparatus for a pipe-shaped metal base material according to the present invention, preferably, an air discharge valve 70 is formed on one side of the expanding means 30, and the air discharge valve 70 is A valve seat 72 inserted into the main body of the expansion means 30 and forming a locking groove 72b at the inner peripheral edge of the internal discharge hole 72a; a traction ring 74 supported and installable on the valve seat 72; An opening valve 76 press-fitted into the discharge hole 72a and having an outer edge provided with a locking projection 78b capable of closely adhering to the locking groove 72b and an insertion hole 76a formed therein, and an insertion hole 76a of the opening valve 76. The traction ring 74, the release valve 76, and the valve cap 78 are formed so that they can be inserted into the tubing and have vent holes 78a formed therein. It is characterized by being connected to the main pulling wire via 0 ".

Further, in the welding device for pipe-shaped metal base materials according to the present invention, preferably, the air discharge valve 70 of the expanding means 30 is configured such that the auxiliary traction wires 60, 60 ', 60 "draw the main traction wire 64. By pulling the main traction wire 64, the auxiliary traction wire 60 is first drawn and the valve cap 78 is withdrawn from the opening valve 76, and subsequently by pulling the main traction wire 64, The auxiliary traction wire 60 ′ is pulled, the release valve 76 is pulled out of the valve seat 72, the discharge hole 72 a is opened, and the main traction wire 64 is subsequently drawn, whereby the auxiliary traction wire 60 ″ is drawn. The auxiliary traction wires 60, 60 'are extended so that the traction ring 74 and the extension means 30 can be withdrawn. The length of 60 ", characterized in that it is adjusted.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of a welding apparatus for a pipe-shaped metal base material according to the present invention, FIG. 1 is a perspective view of the present embodiment, FIG. 2 is a sectional view of FIG. 1, and FIG. 2 and FIG. 4 are exploded views of the air discharge valve according to the present embodiment.

As shown in FIG. 1, the welding device between the pipe-shaped metal base materials of the present embodiment comprises an expanding means 30 and a heat insulating band layer 3.
2 and a welding backside support block group 39. The expansion means 30 is formed by forming a shrinkable substance such as rubber into a hollow spherical shape, and is capable of injecting or discharging air according to a desired operation. The heat insulating band layer 32 is provided on the outer periphery of the expanding means 30, and is fixed to the band 31 in such a manner that the end portions of a large number of heat insulating bands 33 respectively overlap the front ends thereof. The welding back surface support block group 39 is provided with alternately regular trapezoidal blocks 35 and inverted trapezoidal blocks 36 on the upper surface of the heat insulating band layer 32, and these are connected by wires 37. The upper and lower trapezoid blocks 35 and 36 have an upper surface formed in an arc shape, and concave grooves 34 and 34 'are formed in the center along the longitudinal direction, respectively.
Also, inclined side surfaces 35 ′ and 36 ′ are slidably in contact with each other, and are slid in the radial direction from the center of the expanding means to form the concave grooves 34 and 34 ′.
Are connected.

As shown in FIGS. 1 and 2, the expansion means 30 is provided with an air discharge valve 70 on one side thereof. As shown in FIGS. 3 and 4, the air discharge valve 70 is mounted on the main body of the expansion means 30 and has a locking groove 72b formed in the inner peripheral edge of the internal discharge hole 72a. Penetrated expansion means 30 and valve seat 72
A traction ring 74 formed so as to be supported between the head 72c of the valve seat 72 and a discharge hole 72a of the valve seat 72 which is press-fitted so that an outer peripheral edge thereof is in close contact with a locking groove 72b of the valve seat 72. And an opening valve 76 having an insertion hole 76a formed therein, and a valve cap 78 inserted into the insertion hole 76a of the opening valve 76 and having a ventilation hole 78a formed therein. .

The traction ring 74, the release valve 76 and the valve cap 7
8 is connected to the main traction wire 64 via auxiliary traction wires 60, 60 ', 60 ", respectively. The auxiliary traction wires 60, 60', 60" are pulled by pulling the main traction wire 64 to provide auxiliary traction. After the valve cap 78 is pulled out of the opening valve 76 by the wire 60 and the valve cap 78 is pulled out of the opening valve 76, the auxiliary traction wire 60 'is pulled out.
The opening of the opening valve 76 is performed by the auxiliary pulling wire 6 after the opening valve 76 is withdrawn from the valve seat 72.
The lengths are different so that the traction ring 74 and the expansion means 30 are simultaneously pulled by "0".

Although the expansion means 30 is formed in a spherical shape in the illustrated embodiment, the expansion means 30 can maintain the airtight state by uniformly pressing the inner surface of the metal pipe while inflating uniformly by injecting air. If it is a form, it may be formed in various forms such as a column. As shown in FIG. 6 to be described later, holes 40 are provided in the normal trapezoidal block 35 and the reverse trapezoidal block 36. Are connected to each other.

Next, a method for welding between pipe-shaped metal base materials using the welding apparatus of the present embodiment will be described with reference to FIGS.

First, as shown in FIGS. 5 and 9, a predetermined amount of air is injected into the expansion means 30. At this time, the air is injected from the space between the routes 5 of the pipe base materials P1 and P2 to be welded by the air injection valve V provided on the expansion means 30.
While inserting a syringe needle or other air injecting device V ₁
This is performed using air injection means or the like not shown.

In this state, the heat-insulating band layer 32 is wound around the outer peripheral surface of the expanding means 30, and the forward and reverse trapezoidal blocks 35, 36 of the welding back support block group 39 are arranged along the center of the heat-insulating band layer 32. The inclined side surfaces 35 ′ and 36 ′ are provided so as to be shifted from each other in the radial direction of the expanding means 30. At this time, each groove 34, 3 of the welding backside support block group 39
Positions such as 4 'are provided so as to coincide with the position of the route 5 of the pipe base materials P1 and P2 to be welded as shown in FIG. The outer diameter of the welding back surface support block group 39 formed by the forward / reverse trapezoidal blocks 35 and 36 is smaller than the inner diameter of the pipe base materials P1 and P2 to be welded.

In this manner, the pipe-shaped metal base materials P1,
After completing the above-described series of installation steps in which the concave grooves 34 and 34 'of the welding back surface support block group 39 are aligned with the route 5 which is the welding portion of P2, the inside of the expanding means 30 is substantially the same as described above. Inject air again by the method. In addition, a hole (not shown) is provided in the welding back surface support block group 39 so that a needle or the like can be inserted into the air injection valve V of the expansion means 30, and air can be injected into the expansion means 30. It has become.

As the air is injected into the expanding means 30, the inclined trapezoidal block 35 and the inverted trapezoidal block 36 slide on their inclined side surfaces 35 'and 36'. When the inclined side surfaces 35 'and 36' slide toward each other, the respective grooves 34 and 34 'approach each other, and the outer diameter of the welding back surface support block group 39 becomes equal to the inner diameter of the pipe base materials P1 and P2. 7 and 10, the concave grooves 34 and 34 'of the normal trapezoidal block 35 and the reverse trapezoidal block 36 are brought into communication with their bottom surfaces being coincident with each other. The outer diameter of 39 is substantially equal to the inner diameter of the pipe base materials P1 and P2, and the regular trapezoidal block 35 and the inverted trapezoidal block 36 have concave grooves with their outer peripheral surfaces abutting the inner peripheral surfaces of the pipe base materials P1 and P2. 34,3
4 'comes to coincide with route 5. In such a state, if normal welding is performed from the outside of the pipe base material along the welded portion between the pipe base materials P1 and P2, the welding operation can be performed from the outer surface.

However, the operation of matching the route 5 of the pipe base materials P1, P2 in a state where the heat insulating band layer 32 and the welding back surface support block group 39 are accurately aligned at the center of the outer peripheral edge of the expanding means 30 is a manual operation. Cannot be done easily. Therefore, alignment means for aligning the expansion means 30, the heat insulating band layer 32, and the welding back surface support block group 39,
Also, it is desirable to provide an installation means for providing the aligning means on the pipe base materials P1, P2. FIGS. 11 to 14 show an example of a means for arranging a group of welding back-side support blocks and a means for arranging the aligning means used in the welding apparatus according to the present embodiment. 11 and 12 show an exploded view and a sectional view of the alignment means, and FIGS. 13 and 14 show an exploded view and a sectional view of the installation means.

FIGS. 11 and 12 show an alignment jig 80 as an alignment means. The alignment jig 80 includes a support cap 82,
An outer casing 86 provided outside the tension adjusting cap 84 and having a jig mounting portion 86a formed therein; and an outer peripheral surface of the support cap 82. , A tension alignment support group 88 having an insertion space 87a at the tip thereof.

An installation jig 90 is used as an installation means in FIG.
3 and FIG. The main body 92 of the installation jig 90 has a pipe insertion hole 92a inside thereof and a large number of welding grooves 9 on the outer peripheral edge.
2b is formed. Further, the main body 92 is formed so as to be divided into two in the longitudinal direction, and one end of each of the divided main bodies 92 is connected via a hinge portion 92c so that the main body 92 can be opened and closed and can be opened and closed. A fixing member (not shown) is provided so that the end can be fastened and fixed. A support 94 is provided on the outer peripheral surface of the main body 92 of the installation jig 90. The support portion 94 includes a folding step 94.
c and a support plate 94 made of an elastic member such as a leaf spring provided with a slit 94d, and an operating lever 94a loosely fitted in the slit 94d. It is sandwiched by holding members etc.
By pulling the operation lever 94a in the direction of the arrow C (inverting direction), the bent step 94c of the support plate 94 is elastically opened on the outer peripheral edge of the main body 92 to operate. On the outer peripheral surface of the main body 92, a pipe organizing section 96 is provided. The pipe organizing portion 96 includes a rotating frame 96a having one end hinged by a hinge member 96c and a plurality of bolt holes provided at the other end. By screwing the fixing bolt 96b into the bolt hole at the tip, the pipe base materials P1 and P2 can be fixed in a state of being aligned with the welding site. An air supply unit 98 is provided on the outer peripheral surface of the main body 92. The air supply unit 98 supplies air to the inside of the expansion unit 30 via the air needle 97 to expand the expansion unit 30 and to cause the expansion unit 30 to inflate. Base material P1,
The outer peripheral surface of the welding back surface support block group 39 can contact the inner peripheral surface of the pipe at the welding position of P2.

Next, the alignment jig 8 constructed as described above.
One embodiment of the welding method of the present invention is centered on the process of performing welding while installing the heat insulating band layer 32 and the welding back surface support block group 39 on the expansion means 30 using the mounting jig 90 and the expansion means 30 in an aligned state. The configuration will be described with reference to FIGS.

First, as shown in FIG. 15, the heat insulating band layer 32 formed in a ring shape is inserted into the insertion space 87a at the tip of the tension alignment support group 88 of the alignment jig 80 and wound around the tension alignment support group 88. Next, when the welding back support block group 39 is wound along the outer peripheral surface of the band layer 32, the forward / reverse trapezoidal block 3 of the welding back support block group 39 is wound.
One of the side surfaces 35 ", 36" of the pair 5, 5 is abutted against one end 87b of the tension alignment support piece 87 forming the insertion space 87a. It is arranged so that it is located in. Note that the width of the heat insulating band layer 32 is formed in advance so as to be larger than the width of the forward / reverse blocks 35 and 36 constituting the welding back surface support block group 39.

Next, the outer casing 86 of the alignment jig 80
The mounting jig 90 is mounted on the jig mounting portion 86a. At this time, first, as shown by the one-dot chain line in FIG.
The operating jig 90 is mounted on the jig mounting portion 86a by pulling the operating lever 94a of No. 4 to open the support piece 94b. When the operating lever 94a is returned to the initial position after the installation jig 90 is mounted, as shown by a solid line in FIG. 15, the tips of the support pieces 94b are aligned with the central grooves 34 and 34 'of the welding back surface support block group 39. Becomes repressive.

Next, as shown in FIG. 16, the extension means 30 is arranged inside the tension support alignment group 88. At this time, auxiliary pulling wires 60, 60 ', and 60 "are connected and installed to the expansion means 30 and the air discharge valve 70 of the expansion means. Further, the auxiliary wires 6 connected to the air discharge valve 70 are provided.
3, 63 'are connected to the welding back surface support block group 39 and the heat insulating band layer 32 via a connecting ring or the like.

Next, the air needle 97 of the air supply unit 98 provided on the installation jig 90 is extended through the hole formed in the center of a predetermined block of the welding back surface support block group 39 by the expansion means 3.
The air supply unit 98 is connected to an air supply source (not shown) through the air supply valve 98, and a predetermined amount of air is supplied to the inside of the expansion means 30 through the air needle 97. Then, the expansion means 30 pushes the tension support row pieces 87 of the alignment jig 80 outward while gradually expanding.

As the expanding means 30 expands, the diameter thereof is gradually expanded in a state where the heat insulating band layer 32 located on the outer peripheral surface of the central portion and the welding back support block group 39 are aligned, and the installation is repaired. The support portion 94 of the tool 90 resiliently supports the central portion of the welding back surface support block group 39 by the support bending step 94c of the support piece 94b,
At this time, the forward and reverse trapezoidal blocks 35 and 36 of the welding back surface support block group 39 are inclined side surfaces 35 ′ and 36 ′.
Are shifted from each other, and their outer diameters are formed smaller than the inner diameters of the pipe base materials P1 and P2 to be welded.

After the alignment of the expansion means 30, the heat-insulating band layer 32, and the welding back support block group 39 is completed on the alignment jig 80 while being supported by the installation jig 90, FIG. As shown, the installation jig 90 is aligned with the alignment jig 8.
0 from the jig mounting portion 86a.
Pipe base material P to be welded to the pipe insertion hole 92a
Attach to the end of 1. At this time, the auxiliary index wire 60,
As shown in FIG. 18, 60 ', 60 "are connected to a main pulling wire 64 provided so as to penetrate the pipe P1. As shown in FIG.
Is in contact with the inside of the supporting bent step 94c.

Next, the end of the pipe base material P2 to be welded is positioned so as to contact the outside of the supporting bent step 94c, and in this state, as shown in FIG. Is turned around a hinge provided on one side, and a fixing bolt 96b is screwed into a bolt hole at the tip of the turning frame 96a.
The pipe base material P2 is fixed at the end of b.

After such a series of installation steps are completed, an air supply source (not shown) provided on the installation jig 80 is operated, and the air of the expansion means 30 is expanded by the air needle 97 as described above. Air is again injected into the expansion means 30 through the injection valve V to gradually expand the expansion means 30.

As the expanding means 30 is inflated, the trapezoidal blocks 35 and the inverted trapezoidal blocks 36 of the welding backside support block group 39 slide the mutually inclined inclined side surfaces 35 'and 36'. Can be The air is injected into the expansion means 30 by expanding the expansion means 30 and, as shown in FIG. 21, the pipe base materials P1, P2.
The outer peripheral surface of the welding back surface support block group 39 abuts on the inner surface of the route 5 of the welded portion between them, and the process is performed until the concave grooves 34 and 34 ′ provided on the outer peripheral surface match the route 5. The preparation for welding between the pipe base materials P1 and P2 is completed.

At this time, the welding back support block group 39
Is expanded inside the welded portion of the pipe base materials P1 and P2 while being supported by the supporting bent step 94c of the support plate 94b, so that the welded portion between the pipe base materials P1 and P2 can be accurately and accurately formed. It is easily located.

When the normal trapezoidal block 35 and the inverted trapezoidal block 36 of the welding backside support block group 39 are expanded, there is a possibility that they are not ring-shaped but twisted with each other. Are assembled in a form shifted from each other (a form in which the outer diameter of the assembled welded back support block group 39 is smaller than the inner diameter of the pipe base material), and in order to maintain the form, a paper material that is easily broken separately Alternatively, the above-mentioned twisting or the like can be prevented by connecting and assembling using a maintenance tool or the like having properties similar to this.

As shown in FIG. 22, if the concave and convex portions are formed so as to be fitted on the inclined side surfaces 35 'and 36' of the normal trapezoidal block 35 and the reverse trapezoidal block 36 which are in sliding contact with each other, the alignment state can be improved. It is preferable because it can be maintained.

The concave and convex portions 45 and 46 are locked to each other, and their movement direction is restricted only in a direction along the radial direction from the center of the moving means 30. The block 36 does not shift sideways. The wire 37 is connected to the forward / reverse trapezoidal blocks 35, 3
6 can be used for removal.

When welding is performed, the pipe base material P
The inner diameters of 1 and P2 are not always the same, and the diameters of the inner diameters of the pipe base materials may be different from each other. In order to do so, the number of the forward / reverse trapezoidal blocks 35, 36 may be adjusted, or the forward / reverse trapezoidal blocks 35, 36 may be aligned for a plurality of sizes.

Further, as shown in FIG. 23, when the pipe base materials P1 and P2 to be welded are brought into contact with each other, the inner surface of the pipe base material is not always aligned in a straight line and a slight error T occurs.
Alternatively, it may be necessary to perform welding with a slight error T. In such a case, as shown in FIG. 22, a predetermined angle is formed on the side edges along the longitudinal direction of the forward and reverse trapezoid blocks 35, 36. If the tapered surfaces 43, 43 are formed so that either one of the tapered surfaces 43, 43 can abut on the pipe base material P1 or P2, the forward / reverse trapezoid block 3
The route 5 and the grooves 34, 34 are formed without a large gap between the outer peripheral surfaces of the pipes 5 and 36 and the inner peripheral surfaces of the pipe base materials P1 and P2.
34 'is preferable because the position can be adjusted.

The heat insulating band layer 3 used in the present invention
As shown in FIG. 24, a number of heat insulating bands 33 are sewn on the band 31 so that one side end of the band is overlapped with the other end. The size can be changed.

As described above, by expanding the expanding means 30, the concave portions 34 and 34 'of the outer peripheral surface of the welding back surface support block group 32 are brought into contact with the inner surface of the root 5 of the welding portion between the pipe base materials P1 and P2. At least after the welding preparation is completed,
Weld groove 92 formed along the periphery of installation jig 90
A part of the welded portion between the pipe base materials P1 and P2 is temporarily attached via b.

After the tacking between the pipe base materials P1 and P2 is completed, the installation jig 90 is removed from the pipe base materials P1 and P2. To remove the installation jig 90, first, the fixing bolt 96b of the pipe alignment portion 96 is removed to release the fixing state to the pipe P2. Next, the other bolts are removed and the rotating frame 9 is removed.
6 is rotated around the hinge 96c to return to the initial position,
In this state, the main body 92 of the installation jig 90 is opened, and the installation jig 90 is removed from the pipe P1.

In this way, the installation jig 9 is placed on the pipe P1.
Then, when the metal is melted outside the pipe base materials P1 and P2 and the groove formed at the abutting portion of the pipe base materials P1 _and P is filled with the weld metal, the weld metal is removed from the pipe base materials P1 and P2. The P2 groove surface is cooled while melting together to form a weld seam. Also,
The weld metal that has flowed through the route 5 of the pipe base materials P1, P2 is filled in the concave grooves 34, 34 'formed in the forward and reverse trapezoidal blocks 35, 36. At this time, since the surfaces of the forward and reverse trapezoid blocks 35 and 36 are in close contact with the pipe base material, the back bead can be formed in the same shape as the concave grooves 34 and 34 'without contacting oxygen.

Further, since the heat generated during welding is cut off by the forward and reverse trapezoidal blocks 35 and 36, the expanding means 30 is not adversely affected by the welding heat.
Even if some heat is transmitted, the heat insulating band layer 32 blocks the heat sufficiently to prevent the expansion means 30 from being damaged by heat.

It should be noted that the metal to be welded is a trapezoidal block 35, 3
It is conceivable that the gap 6 melts into the gap between the inclined side surfaces 35 ′ and 36 ′ that are in contact with each other. The outer peripheral surfaces of the forward and reverse trapezoidal blocks 35, 36 are pressed against the pipe base materials P1, P2 by the expansion force of the pipes to maintain a ring shape.
5 'and 36' are inclined with respect to each other. For this reason, the sides are pressed against each other and closely adhered to each other, so that there is no possibility that a gap is generated, and the deposited metal easily passes between the forward and reverse trapezoidal blocks 35 and 36 and does not reach the heat insulating band layer 32 at all. Become.

The forward and reverse trapezoid blocks 35 and 36 are usually made of a ceramic material or a material similar thereto in order to have excellent heat resistance and to prevent a chemical influence on a metal welding portion. It is preferred to be manufactured by

After completing a series of welding operations in this way, the expansion means 3 is extended through the air discharge valve 70 of the expansion means 30.
If the air inside is discharged to the outside, the pipe base materials P1, P
Backside support block group 3 closely adhered to the inner surface of 2
Since the ring form 9 is dismantled, it may be pulled out. Hereinafter, the procedure will be described in detail. As shown in FIG. 25, when the main pulling wire 64 extending to the outside through the pipe P1 is pulled, the auxiliary pulling wires 60, 60 ′, 60 ″ connected to the main pulling wire 64 are drawn. Of these wires, the auxiliary pulling wire 60 having the shortest length pulls out the valve cap 78 from the insertion hole 76a of the opening valve 76. At this time, air flows into the inside of the opening valve 76 through the ventilation hole 78a of the valve cap 78. The valve cap 78 press-fitted into the opening valve 76 can be easily removed.

The auxiliary pull wire 60 allows the valve cap 7
8 is completely withdrawn from the release valve 76 and subsequently the main traction wire 64 is pulled, the auxiliary traction wire 60
Next, the auxiliary pulling wire 60 ′ having the shorter length draws the opening valve 76 from the discharge hole 72 a of the valve seat 72. At this time,
Since the valve cap 78 is pulled out from the inside of the opening valve 76, the opening valve 76 moves inward of the opening valve 76 while the locking projection 76 b of the opening valve 76 slides on the locking groove 72 b of the valve seat 72. So that it can be easily pulled out of the valve seat 72.

[0065] Opening valve 76 is provided by auxiliary pulling wire 60 '.
Is completely pulled out of the valve seat 72, the discharge hole 72
a is released, the air inside the expansion means 30 is discharged through the discharge hole 72a, and the expansion means 30 which has been expanded is contracted, and the welding back surface support block group 39 on the outer peripheral edge thereof is formed. The heat insulation band 32 is isolated from the state in which the heat insulation band 32 is closely attached to the inner surfaces of the pipes P1 and P2.

Subsequently, when the main pulling wire 64 is drawn to pull the auxiliary pulling wires 60, 60 ', 60 ", the auxiliary pulling wire 60" is moved together with the pulling ring 74 through the head 72c of the valve seat 72 through the valve seat 72. And the expansion means 30 with the valve seat 72 inserted thereinto are pulled out simultaneously.

The above-mentioned traction ring 74 and auxiliary traction wire 6
The group of welded backing support blocks 39 and the heat insulating band layer 32 connected via the third and the 63 'are drawn out via the auxiliary pulling wires 63 and 63' next to the expanding means 30. At this time, it is preferable that the lengths of the auxiliary pulling wires 63 and 63 'be different because the back support block group 39 and the heat insulating band layer 32 are gradually pulled out in order.

In this way, by pulling the main pulling wire 64, the expanding means 30, the heat insulating band layer 32, the welding back surface support block group 39 and the like are easily separated inside the pipe preforms P1, P2. It can be pulled outside the base material.

FIG. 26 shows an embodiment in which a plurality of pipe base materials to be welded are P1, P2, P3, P4, and P5, and a plurality of welds are to be made. In the present embodiment, the welding device of the present invention is provided at each of a plurality of welding locations, and a second pulling wire 64 ′ is provided on the side of the expanding means 30 opposite to the side where the main pulling wire 64 is provided. The extension means 30 is connected to each other.
In this embodiment, if the second pulling wire 64 'is connected to the welding device of the present invention provided at the next welding point in the same manner as the main pulling wire 64, a series of welding operations can be performed at a plurality of points. After finishing, the first main pulling wire 64 is pulled, so that the welding devices of the present invention provided at a plurality of welding locations are connected to the pipe base materials P1, P2, P3, P4.
, P5.

FIGS. 27 and 28 show another embodiment of the welding apparatus according to the present invention. In the welding device of the present embodiment,
A flexible adhesive tape 47 is provided on the inner peripheral surface of the welding back support block group 39 in which the forward and reverse trapezoidal blocks 35 and 36 are shifted from each other. The adhesive tape 47
As shown in FIG. 28, the width is formed so as to be able to adhere to the inner surfaces of the metal pipe base materials P1, P2 to be welded so as to surround the welding back surface support block group 39. still,
Other configurations are substantially the same as those in the above embodiments. According to the present embodiment, as shown in FIG. 27, first, the flexible adhesive tape 47 is directly provided on the inner surface of the welding back surface support block group 39 as described above,
When a predetermined amount of air is injected into the inside of the expansion means 30 and the expansion tape 30 is expanded, the adhesive tape 47 is supported on the outer peripheral edge of the central part of the expansion means 30 by the expansion of the expansion means 30. Thereafter, the grooves 34, 3 of the welding back support block group 39 are formed on the bottom surface of the root 5 of the metal pipe base materials P1, P2 to be welded.
The position of 4 'coincides.

At this time, the main pulling wire 64 connected to the auxiliary wires 60, 60 ', 60 "provided on the expanding means 30 has the welding back surface support block group 39 and the adhesive tape 47 attached to the auxiliary pulling wires 63a, 63a. 63a '.

When air is again supplied to the expansion means 30 after the above state, the expansion means 30 is expanded, and as described above, the welding back surface is connected to the route 5 of the metal pipe base materials P1, P2. Each concave groove 34 of the support block group 39,
In the state where 34 'coincides with each other, the outer peripheral surface of the group of welding back support blocks 39 comes into contact with the inner peripheral surfaces of the metal pipe preforms P1, P2. As shown in FIG. 28, a group of welded back support blocks is attached with a flexible adhesive tape 47 adhered to the inner peripheral surfaces of the metal pipe base materials P1 and P2 so as to surround the weld back support blocks 39. 39 is fixed to the metal pipe base materials P1 and P2.

After such a state, the main pulling wire 64
Is pulled out by a predetermined length, as described above, the air inside the expanding means 30 is exhausted, and as shown in FIG. 29, the expanding means 30 is pulled out while being isolated from the welded portions of the metal pipe base materials P1, P2. At this time, the back support block group 39
Is kept fixed to the welded portions of the metal pipes P1, P2 by the adhesive tape 47. The auxiliary pulling wires 63a and 63a 'have a sufficient length, so that the welding back surface support block group 39 and the adhesive tape 47 are not pulled out by the pulling of the main pulling wire 64 for the predetermined length. It has become.

In this state, as described above, the welding between the metal pipe base materials P1 and P2 is performed, and then the main pulling wire 64 is further drawn. The welding back support block group 39 and the adhesive tape 47 fixed to the welding portions P1 and P2 are pulled out of the metal pipe base materials P1 and P2 and separated.

According to this embodiment, the metal pipe base material P1
, And P2, the welding back surface support block 39 is fixed by an adhesive tape 47 so that the expansion means 30 can be isolated from the welded portion so that welding can be performed. However, the expansion means 30 can perform the welding operation without being affected by the welding heat input as described above.

[0076]

As described above, according to the method and the apparatus for welding between pipe-shaped metal base materials of the present invention, it is possible to prevent the flow of deposited metal to the inner surface of the pipe-shaped base material when welding between pipe-base materials. In addition, the back bead can be formed while blocking the contact with the air, and even in the case of TIG welding, the inside can be welded without having to be replaced with an inert gas. Further, the welding operation can be performed efficiently even when a plurality of welded portions are formed between the pipe base materials.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a welding device for a pipe-shaped metal base material according to the present invention.

FIG. 2 is a sectional view of FIG. 1;

FIG. 3 is an enlarged sectional view of a main part of FIG. 2;

FIG. 4 is an exploded perspective view of the air discharge valve of FIG. 3;

FIG. 5 is a reference cross-sectional view illustrating one process of a welding method using the welding device of the present embodiment.

FIG. 6 is an enlarged sectional view of a part A in FIG. 5;

FIG. 7 is a reference cross-sectional view illustrating another process of the welding method using the welding device of the present embodiment.

FIG. 8 is an enlarged sectional view of a part B of FIG. 7;

FIG. 9 is a reference longitudinal sectional view illustrating one process of a welding method using the welding device of the present embodiment.

FIG. 10 is a reference vertical sectional view showing another process of the welding method using the welding device of the present embodiment.

FIG. 11 is an exploded perspective view of an alignment jig used for the welding device of the present embodiment.

FIG. 12 is a sectional view of an alignment jig used in the welding device according to the embodiment.

FIG. 13 is a partially exploded perspective view of an installation jig used in the welding device of the present embodiment.

FIG. 14 is a side view of an installation jig used in the welding device of the present embodiment.

FIG. 15 is a cross-sectional view showing a use state of the present embodiment using the alignment jig and the installation jig.

FIG. 16 is a sectional view showing another use state of the present embodiment using the alignment jig and the installation jig.

FIG. 17 is a cross-sectional view showing still another use state of the present embodiment using the alignment jig and the installation jig.

FIG. 18 is a sectional view showing still another use state of the present embodiment using the alignment jig and the installation jig.

FIG. 19 is a partial cross-sectional view showing a use state of the present embodiment using the installation jig.

FIG. 20 is a partial cross-sectional view showing another use state of the present embodiment using the installation jig.

FIG. 21 is a partial sectional view showing still another use state of the present embodiment using the installation jig.

FIG. 22 is a perspective view showing a modified example of a group of welding back support blocks used in the present invention.

FIG. 23 is a partial sectional view showing still another embodiment of a group of welded back support blocks used in the present invention.

FIG. 24 is a partially enlarged perspective view of a heat insulating band layer used in the present invention.

FIG. 25 is a partial cross-sectional view showing an operation state of an air discharge valve of an expansion unit in each of the above embodiments.

FIG. 26 is a diagram showing another embodiment of the present invention.

FIG. 27 is a sectional view showing still another embodiment of the present invention.

FIG. 28 is a sectional view showing one state of use in the embodiment of FIG. 27;

FIG. 29 is a sectional view showing another use state of the embodiment in FIG. 27;

FIGS. 30A and 30B show a conventional welding process and a conventional welding process, wherein FIG. 30A shows a welding state from the outer surface of the welding base material, FIG. 30B shows a state in which the back surface of the welding base material is gouged, and FIG. FIG. 4 is a diagram showing a re-welded state from the back side.

FIG. 31 is a diagram showing a conventional welding process and its method.

[Explanation of symbols]

 5 Route 30 Extension Means 31 Band 32 Insulated Band Layer 33 Insulated Band 34, 34 'Groove 35 Regular Trapezoidal Block 35' Slant Side 36 Reverse Trapezoidal Block 36 'Reverse Slant Side 37 Wire 39 Welding Backside Support Block Group 43 Taper 45, 46 Uneven portion 47 Adhesive tape 60, 60 ', 60 "Auxiliary traction wire 64 Main traction wire 70 Air discharge valve 72 Valve seat 72a Discharge hole 72b Lock groove 74 Traction ring 76 Open valve 76a Insert hole 78 Valve cap 78a Vent hole 80 Alignment jig 90 Installation jig P1, P2, P3, P4, P5 Pipe base material

Claims (10)

(57) [Claims] 1. A method of welding between pipe base materials, comprising: a trapezoidal block and a reverse trapezoidal block provided so as to contact alternately inclined side surfaces, and a welding back surface in which the regular trapezoidal block and the reverse trapezoidal block are connected by a wire. A supporting block group and a heat insulating band layer formed by sewing a large number of heat insulating band pieces on the inner surface of the welding back surface supporting block group are provided on an outer peripheral surface of expansion means capable of injecting and discharging air. And the expansion means is expanded to inflate the expansion means, so that the front trapezoidal block and the reverse trapezoidal block slide on each other's inclined side surfaces, so that the outer peripheral surface of the welding back surface support block group presses the inner peripheral surface between the pipe base materials. The pipe base material is welded so that the position of the route between the central part of the group of welding back support blocks and the pipe base material coincides with each other. Welding method between looped metal matrix. 2. A flexible adhesive tape is provided on the inner surface of the group of welding back support blocks, and air is injected into the inside of the expanding means to expand the expanding means so that the position of the route between the pipe base materials is reduced. After the adhesive tape is adhered to the inner peripheral surface of the pipe base material so as to surround the welded backing support block group in a state where the adhesive tape is aligned with the center portion of the welded backing support block group, and the welded backing support block group is fixed. The method for welding between pipe-shaped metal base materials according to claim 1, wherein the expansion means is isolated from a welding portion of the pipe base material, and thereafter, the pipe base materials are welded. 3. The pipe-shaped metal mother according to claim 1, wherein a back bead can be formed by a concave groove formed in a longitudinal direction of a central portion of said forward / reverse trapezoidal block. Welding method between materials. 4. A welding device for a pipe base material, wherein expansion means 30 having a predetermined size capable of adjusting air injection or discharge, and a plurality of heat-resistant bands 33 are fixedly mounted on a band 31 so that ends of the heat-resistant bands 33 overlap with each other. And a trapezoidal block 35 and a reverse trapezoidal block 36 in which concave grooves 34 and 34 'are respectively formed in the longitudinal direction of the central portion are provided alternately, and these are connected by a wire 37 and the trapezoidal block. 35. A pipe-like shape comprising a welded back surface support block group 39 which is slidable in a state where the inclined side surface 35 'of the 35 and the inverted inclined side surface of the inverted trapezoid block are in contact with each other. Welding equipment between metal base materials. 5. An uneven portion 45, which can be fitted to the inclined side surfaces 35 ', 36' of said forward / reverse trapezoid blocks 35, 36.
The welding device between pipe-shaped metal base materials according to claim 4, wherein 46 is formed. 6. The method according to claim 4, wherein the outer peripheral surfaces of the forward and reverse trapezoidal blocks have a curved surface formed so as to conform to the inner peripheral surface of the pipe base material. Welding equipment between pipe-shaped metal base materials. 7. A taper 43 is provided on each of the forward and reverse trapezoidal blocks 35 and 36 so as to have a predetermined angle at a longitudinal edge of an outer peripheral surface thereof.
The welding device between pipe-shaped metal preforms according to claim 1. 8. The outer diameter of the welding back surface support block group 39 can be adjusted by adjusting the size and the number of the forward and reverse trapezoidal blocks 35, 36 according to the inner diameter of the pipe base material. The welding device between pipe-shaped metal base materials according to claim 4, characterized in that: 9. The expansion means 30 has an air discharge valve 70 formed on one side thereof. The air discharge valve 70 is inserted into the main body of the expansion means 30 and is provided in an internal discharge hole 72a. Locking groove 7 on the periphery
2b; a traction ring 74 supported and installed in the valve seat 72; and a press-fit installation in a discharge hole 72a of the valve seat 72, the outer edge of which can be in close contact with the locking groove 72b. Opening valve 7 having locking projection 78b and insertion hole 76a formed therein
6, a valve cap 7 formed to be insertable into the insertion hole 76a of the opening valve 76 and having a ventilation hole 78a formed therein.
8, the traction ring 74, the release valve 76 and the valve cap 78
The welding device between pipe-shaped metal base materials according to claim 4, wherein the main pulling wires are connected to the main pulling wires via auxiliary pulling wires 60, 60 ', and 60 ", respectively. 10. The air discharge valve 70 of the expansion means 30
The auxiliary traction wires 60, 60 ′, 60 ″ are the main traction wires 6
4, the pulling of the main pulling wire 64 first pulls the auxiliary pulling wire 60, pulls the valve cap 78 out of the opening valve 76, and subsequently pulls the main pulling wire 64. As a result, the auxiliary traction wire 60 ′ is pulled, the release valve 76 is withdrawn from the valve seat 72, the discharge hole 72 a is opened, and the main traction wire 64 is subsequently drawn, whereby the auxiliary traction wire 60 ″ is drawn. The auxiliary traction wire 6 is pulled so that the traction ring 74 and the extension means 30 can be pulled out.
The welding device between pipe-shaped metal base materials according to claim 4 or 9, wherein the length of 0, 60 ', 60 "is adjusted.