KR101328327B1 - Tandem Overlay Welding Device - Google Patents

Abstract

An object of the present invention is to provide an overlay welding apparatus including a plurality of welding torch that can increase the overlay welding productivity, for this purpose, a pipe rotating unit for rotating the pipe; And a welding part for overlay welding the inner surface of the pipe in the pipe, wherein the welding part comprises: a boom in which a plurality of welding torches are mounted at an end thereof; A main body connected to the boom and moving the boom; And a cooling unit surrounding the pipe, wherein the plurality of welding torches mounted to the boom are spaced apart from each other by a predetermined distance in a pipe length direction, and the plurality of welding torches are overlay welded to the pipe. And a second welding torch for overlay welding on the welding layer by the welding torch, wherein the first welding torch and the second welding torch are spaced apart from each other by 50 to 150 mm in the longitudinal direction of the pipe, and the cooling unit is formed around the pipe. A plurality of nozzles arranged in a plurality of rows arranged along a direction to cool at least an area corresponding to a position of a rear end of the second welding torch from an area corresponding to the position of the first welding torch, wherein the cooling unit is in a circumferential direction of the pipe A nozzle connector connecting one or more of the plurality of nozzles disposed along the side; And a nozzle moving part connected to the nozzle connecting part to move the nozzle connecting part in a radial direction of the pipe, wherein the nozzle moving part is capable of moving the nozzle connecting part in the radial direction of the pipe according to the diameter of the pipe. Provide an overlay welding apparatus.

Description

Tandem Overlay Welding Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tandem overlay welding apparatus, wherein in performing overlay welding on a pipe inner surface, a tandem overlay welding apparatus for welding an outer surface of a pipe to a first layer and a second layer over the first layer.

1 is a diagram showing an overlay welding apparatus 1 according to the prior art.

The conventional overlay welding apparatus 1 includes a boom 10 having a cantilever structure in which a welding torch 20 is mounted on a free end and a main body 30 is connected to a fixed end in a steel pipe P, And a utility connected to the main body and connected to the welding torch 20 through the boom 10. Here, the utility includes a power supply unit 40 for supplying power to the welding torch 20, an inert gas supply unit 50 for supplying an inert gas 15 at the welding, cooling water for supplying cooling water for cooling the welding torch 20 (60) and welding wire (17). The welding torch 20 over-welds the inner surface of the steel pipe P by receiving utility from the power supply unit 30, the inert gas supplier 50, the cooling water supply unit 60 and the welding wire supply unit 70.

At this time, the steel pipe (P) is cooled by spraying water from the upper portion of the pipe (P) rotated through the coolant nozzle (80) so that the temperature rises by overlay welding so as not to overheat.

It is an object of the present invention to provide an overlay welding apparatus comprising a plurality of welding torches that can increase overlay welding productivity.

It is also an object of the present invention to provide an overlay welding apparatus capable of providing sufficient cooling to enable the welding of multilayer layers.

Moreover, an object of this invention is to provide the overlay welding apparatus which grasps the cooling state of a pipe and controls cooling.

The present invention provides an overlay welding apparatus as follows to achieve the above object.

The present invention is a pipe rotating unit for rotating the pipe; And a welding part for overlay welding the inner surface of the pipe in the pipe, wherein the welding part comprises: a boom in which a plurality of welding torches are mounted at an end thereof; A main body connected to the boom and moving the boom; And a cooling unit surrounding the pipe, wherein the plurality of welding torches mounted to the boom are spaced apart from each other by a predetermined distance in a pipe length direction, and the plurality of welding torches are overlay welded to the pipe. And a second welding torch for overlay welding on the welding layer by the welding torch, wherein the first welding torch and the second welding torch are spaced apart from each other by 50 to 150 mm in the longitudinal direction of the pipe, and the cooling unit is formed around the pipe. A plurality of nozzles arranged in a plurality of rows arranged along a direction to cool at least an area corresponding to a position of a rear end of the second welding torch from an area corresponding to the position of the first welding torch, wherein the cooling unit is in a circumferential direction of the pipe A nozzle connector connecting one or more of the plurality of nozzles disposed along the side; And a nozzle moving part connected to the nozzle connecting part to move the nozzle connecting part in a radial direction of the pipe, wherein the nozzle moving part is capable of moving the nozzle connecting part in the radial direction of the pipe according to the diameter of the pipe. Provide an overlay welding apparatus.

In addition, the cooling unit is provided with a moving means, the cooling unit may be moved together with the movement of the main body for moving the welding torch.

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In the present invention, the nozzle connection is divided into two or more with the same angle along the circumferential direction of the pipe, the number of nozzles connected to the nozzle connection toward the pipe passed through the welding torch of the nozzle connection, passing through the welding torch There may be more than the number of nozzles connected to the nozzle connection towards the pipe.

The cooling unit may further include: a water tank configured to collect cooling water used in the lower portion of the pipe, and a pump to supply the cooling water collected in the water tank back to the nozzle; Mounted on each welding torch, and connected to each of the non-contact temperature sensor and the non-contact temperature sensor for measuring the temperature of the pipe rotated to the position of each welding torch, between the nozzle and the water tank to adjust the amount of cooling water injected into the pipe It may include; a control unit for controlling the quantity control valve provided in.

The present invention is to achieve the above configuration, and provides an overlay welding apparatus including a plurality of welding torch that can increase the overlay welding productivity.

In addition, the present invention provides an overlay welding apparatus capable of providing sufficient cooling to enable welding of a multilayer layer.

In addition, the present invention provides an overlay welding apparatus that controls the cooling by grasping the cooling state of the pipe.

1 is a schematic view of a conventional overlay welding apparatus.
2 is a perspective view of an overlay welding apparatus of the present invention.
3 is a side cross-sectional view of the overlay welding apparatus of the present invention.
4 is an operational state diagram of the cooling unit of the overlay welding apparatus of the present invention.
5 is an operating state diagram of the cooling unit when the diameter of the pipe in the overlay welding apparatus of the present invention is changed.
6 is a flow chart of the coolant of the overlay welding apparatus of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the overlay welding apparatus, the inner surface of the pipe P may be overlay welded in two or more layers. This is because the first layer degrades the performance of the overlay weld due to dilution with the base material, so that the first layer is used as a buffer layer and overlay welding of the second layer laminated on the first layer ensures corrosion resistance. It is possible to do

In this multilayer overlay welding, the first layer must be welded first and then the overlay welding again to weld the second layer. In the case of overlay welding, the welding speed is very slow because the entire surface of the pipe P is welded. In the case of overlay welding of plies, it takes twice the time to overlay one ply, which can result in very low productivity.

Thus, the inventor of the present invention has developed a tandem overlay welding apparatus to perform the multilayer overlay welding at once, and FIG. 2 is a perspective view of the overlay welding apparatus 1 of the present invention. As shown in FIG. 2, in the overlay welding apparatus 1 of the present invention, the cantilever beam in which the first and second welding torches 430 and 440 are mounted at the free end and the main body 450 is connected to the fixed end inside the pipe P Two booms 410 and 420 of the structure and the main body 450 connected to the fixed ends of the booms 410 and 420 and the main body 410 and 420 are connected to the first and the first through the booms (410, 420) Two utilities connected by welding torches 430 and 440. Although not shown in the perspective view of FIG. 2, a pipe rotating part (not shown) configured to hold and rotate the pipe P is provided on the side opposite to the main body 450 with the pipe P in place.

In addition, the outer side of the pipe (P) is provided with a cooling unit 100 surrounding the pipe (P). The cooling unit 100 may include nozzles 110a to h disposed at regular intervals along the circumferential direction from the outside of the pipe P, and the nozzles 110a to h may include a plurality of nozzles along the length direction of the pipe P. The furnaces 110, 111, 112, 113, 114, and 115 (see FIG. 3) are disposed to cool outside the pipe P heated by the first and second welding torches 430, 440.

3 is a side cross-sectional view of the overlay welding apparatus of the present invention.

As shown in FIG. 3, in the present invention, the overlay welding apparatus includes first and second welding torches 430 and 440 and booms 410 and 42 connecting them, and a plurality of welding torches 430 and 440 The circumferential positions of the pipes P are the same, but are spaced apart at regular intervals D in the longitudinal direction. The first welding torch 440 forward in the moving direction of the main body 450, that is, in FIG. 3, welds the first layer L1 as a buffer layer because the performance of the overlay weld is weakened due to dilution with the base material. The second welding torch 430 is subsequently overlaid on the second layer L2 stacked on the first layer L1.

In the present invention, since the second layer L2 is welded after the distance D after the first layer L1 is overlay welded, the second layer L2 is welded after the first layer L1 is welded. In the meantime, the pipe P due to welding the first layer L1 should be sufficiently cooled. Accordingly, in the cooling apparatus 100 of the present invention, the nozzles 111, 112, 113, and 114 are disposed between the first and second welding torches 430 and 440 to weld the first layer L1 to the second, and then the second. Sufficient cooling of the pipe P is possible between welding the layers L2.

In addition, in the present invention, the distance D between the second welding torch 430 and the first welding torch 440 is preferably 50 mm or more. If it is less than 50 mm, mechanical interference may occur in the utility connection of the first and second welding torches 430 and 440, and after welding the first layer L1 to the second layer L2. This is because the lack of cooling time causes the beads to collapse when the second layer L2 is welded to the second welding torch 430.

Further, in the present invention, the distance D between the first welding torch 440 and the second welding torch 430 is preferably 150 mm or less. Since the distance between the first welding torch 440 and the second welding torch 430 is related to the length of the booms 410 and 420 and the welding time, the distance between the first and second welding torch 430 and 440 When the distance is longer, the movement distance of the main body 450 is increased, so that the time required for one-time overlay welding is increased and productivity is lowered, and the cantilever boom 410 is lengthened and sagging may occur.

The configuration and operation of the cooling unit 100 will be described in detail with reference to FIGS. 4 to 5.

Figure 4 shows the operating state diagram of the cooling unit of the overlay welding apparatus of the present invention, Figure 5 shows an operating state diagram when the cooling unit of the overlay welding apparatus of the present invention is equipped with a spray nozzle, Figure 5 shows the present invention The operating state diagram of the cooling unit is shown when the diameter of the pipe is changed in the overlay welding apparatus.

As shown in FIG. 4, in the present invention, the cooling unit 100 includes a frame 140 having a diameter larger than that of the circular pipe P and a cooling unit body 101 connected thereto. The cooling unit main body 101 includes a water tank 210 disposed below the pipe P and wheels 280 disposed on an outer surface of the main body 101, and are connected to the wheels 280 and the main body 101. The wheel 280 is rotated by a driving means (not shown) accommodated in the cooling unit 100.

On the other hand, the plurality of nozzles (110a ~ h) in the radially inner side of the frame 140 are arranged at equal intervals in the circumferential direction. In the present embodiment, eight nozzles are arranged at intervals of approximately 45 °, but is not limited thereto, and the number may be changed as necessary. Further, the nozzles 110a to h are arranged in a plurality of nozzle rows 110, 111, 112, 113, 114, and 115 along the longitudinal direction of the pipe P, and thus the length of the frame 140 is approximately 500 mm. And evenly distributed over the area welded by the first and second welding torches 430, 440 and the area between them.

On the other hand, the plurality of nozzles (110a ~ h) is connected to one or more sets through the nozzle connector (120a ~ d). The nozzle connectors 120a-d have an intermediate diameter between the pipe P and the frame 140 to be disposed between the pipe P and the frame 140. The nozzle connection body 120a-d consists of a plurality (4 in this embodiment), and the nozzle moving part extended radially so that the nozzle connection body 120a-d can move to the radial direction of the pipe P. FIG. Is connected to 150.

In addition, a flow path is formed in the nozzle connectors 120a to d to distribute the coolant supplied by the coolant connector 130 to the nozzles 110a to h, and to the nozzle connectors 120a to d, the cooling water supply pipe. 130 is connected, the cooling water supply pipe 130 is connected to the cooling water supply pipe 160 outside the frame 140, the pump 220 in the water tank 210 to collect the cooling water falling from the pipe (P) The pressurized cooling water is supplied through.

The nozzle moving unit 150 is connected to a driving means (not shown) to move the nozzles 110a to h together with the nozzle connecting bodies 120a to d. The nozzle moving part 150 moves the nozzle connecting members 120a to d in the radial direction, so that the cooling may be performed over the entire circumferential direction of the pipe P even if the diameter of the pipe P increases.

Meanwhile, inside the pipe P, first and second welding torches 430 and 440 connected to the booms 410 and 420 are disposed, and the first and second welding torches 430 and 440 are pipe rotation parts (not shown). Overlay welding the inner surface of the pipe (P) rotated by. Non-contact temperature sensors 200 and 201 are mounted on the side surfaces of the first and second welding torches 430 and 440, respectively, and the temperature sensors 200 and 201 are mounted to the first and second welding torches 430 and 440. The temperature of the inner surface of the pipe P coming to the lower surface is measured and provided to the controller 300.

When the temperature of the base pipe P is overcooled to 25 ° C. or lower, the shape of the weld bead is convex, and the welding quality is deteriorated. When the temperature of the pipe P is overheated, bending occurs in the pipe P. Therefore, the overlay welding must be stopped and the centering operation must be performed again. Therefore, it is very important for overlay welding that the inner surface of the pipe P measures the temperature and thus controls the supply of cooling water.

In particular, unlike the welding torch 440 for welding the first layer L1 to the pipe P in the present invention, the welding torch 430 for welding the second layer L2 is formed on the first layer L1. Since the two layers L2 must be welded, it is important to measure the temperature through the temperature sensor 200 and to adjust the amount of cooling water in the nozzle rows 112 to 114 between the first and second welding torches 430 and 440 accordingly. Do. This will be described again with reference to FIG. 6.

As shown in FIG. 4, the coolant supplied to the coolant supply pipes 130 and 160 is sprayed to the outer surface of the pipe P through the nozzles 110a to h, and is connected to the first and second welding torches 430 and 440. The pipe P heated by the above is cooled. In the present invention, the nozzles 110a to h are disposed in the circumferential direction of the pipe P, and are arranged in a plurality of rows in the longitudinal direction of the pipe P, so that not only the welded portion of the pipe P but also the neighboring area can be cooled. Thus, it is possible to achieve uniform cooling as a whole.

Cooling water injected into the pipes P by the nozzles 110a to h flows down along the outer circumferential surface of the pipes P and falls as water droplets at the bottom of the pipes P. The falling water is collected by the water tank 210 and circulated back to the nozzles 110a to h through the pump 220 (see FIG. 6).

In the present invention, instead of the nozzles 110a to h for spraying the coolant, a spray nozzle for spraying the coolant may be used. When using the spray nozzle, the overall atmosphere inside the frame 140 may be formed as a cooling atmosphere. It may be more advantageous for uniform cooling.

In the present invention, even when the diameter of the pipe (P) changes, that is, even when the diameter of the pipe (P) increases, the nozzle connecting member (120a ~ d) is moved radially outward by the nozzle moving unit 150 to cool Can be performed. That is, in the present invention, it is possible for the nozzle connecting members 120a to d connecting one or more nozzles 110a to h to move outward in the radial direction by the nozzle moving part 150. This makes it possible to perform cooling by moving the nozzle connecting bodies 120a to d radially outward when the diameter of the pipe P is increased. In FIG. 5, when the diameter of the pipe P is changed, the nozzle connectors 120a to d move to perform cooling.

As shown in FIG. 5, the nozzle connectors 120a-d have been moved radially outward, thus performing cooling even when the space at the nozzles 110a-h is turned on and a larger pipe P enters. can do.

In particular, in the present invention, the number of nozzles connected to the nozzle connector 120a including the nozzles 110a to c toward the pipe P passing through the welding torches 430 and 440 among the nozzle connectors 120a to d is welded. More than the number of nozzles connected to the nozzle connector 120d including the nozzle 110h towards the pipe P to pass through the torch 430, 440. This means that in the present invention, when the nozzle connectors 120a to d are moved in the radial direction, the spraying direction from the nozzles is changed in the radial direction, and thus the nozzle connectors 120a to d are cooled by the nozzle connectors 120a to d. The point of the pipe P changes.

In addition, when welding is performed by the first and second welding torches 430 and 440, heat input occurs to the pipe P, and the cooling unit 100 cools the first and second welding torches. The temperature of the pipe P passing through the 430 and 440 is high, and in the case of the pipe P to pass through the first and second welding torches 430 and 440 due to cooling during one revolution and cooling water therebetween. The temperature is lowered. Accordingly, cooling is further required for the pipe P passing through the first and second welding torches 430 and 440, and in the present invention, a plurality of nozzles 110a to h are formed by the nozzle connecting bodies 120a to d. When moved together, the pipe P passing through the first and second welding torch 430, 440 can be cooled more than the pipe P passing through the first and second welding torch 430, 440. Pipe (P) side nozzle connection (120a) to the pipe (P) side nozzle connection (120a) passing through the welding torch (20) More nozzles (110a ~ h) ).

6 shows a flow chart of the coolant.

As shown in FIG. 6, the coolant collected in the water tank 210 is sent to the cooling tower 240 so that the temperature drops and comes back to the water tank 210, and the nozzle 110 through the coolant pump 220 of the water tank 210. Is provided. Passes through the water volume control valve 230 and the distribution valve 235 before being dispensed to the nozzle 110, where the total amount of cooling water and the amount of cooling water supplied to each nozzle row 110, 111, 112, 113, 114, 115 And the amount of cooling water returned to the water tank 210 is adjusted.

Dispensing valve 235 is disposed for each longitudinal nozzle row to perform longitudinal differential cooling, the number of adjustment valve 230 is disposed one to adjust the amount of cooling water sprayed from the entire nozzle (110 ~ 116). The quantity control valve 230 is connected to the control unit 300 and is controlled by the control unit 300.

The coolant injected from the nozzle 110 cools the pipe P and returns to the water tank 210 disposed below the pipe P along the outer surface of the pipe P. On the inner surface of the pipe P, the temperature sensors 200 and 201 are attached to the first and second welding torches 430 and 440, and the pipe P passing through the first and second welding torches 430 and 440. Measure the inner temperature. The temperature sensors 200 and 201 are connected to the control unit 300, and the control unit 300 controls the amount of cooling water based on the temperature values measured by the temperature sensors 200 and 201 through the water quantity control valve 230. The temperature sensor 200 of the second welding torch 430 for welding the second layer L2 and the temperature sensor 201 of the first welding torch 440 for welding the first layer L1. According to this, the amount of cooling water in each nozzle row 110 to 115 can be adjusted through the injection valve 235.

For example, in the case of the welding material ER309L 1.2 mm, when the temperature of the pipe 300 as the base material is supercooled to 25 ° C. or lower, the shape of the welding bead is convex and the welding quality is lowered. Thus, the temperature sensors 200 and 201 If the value measured by is close to 25 ℃, reduce the amount of cooling water, and if the temperature on the inner surface of the pipe P is close to the bending-induced temperature, increase the amount of cooling water to decrease the temperature of the pipe P. can do.

The overlay welding was performed on the same steel pipe by the overlay welding apparatus according to the present invention and the conventional overlay welding apparatus, and the welding material and the welding time at that time are described in Table 1.

First layer (L1) Second layer (L2) Pipe length (mm) Welding time Inventory 1 ER309L ER308L 1000 7Hr Inventive Example 2 ER309L ER308L 500 4Hr Inventory 3 ER309L ER308L 1500 10Hr Comparative Example 1 ER309L ER308L 1000 12Hr Comparative Example 2 ER309L ER308L 500 6Hr Comparative Example 3 ER309L ER308L 1500 18Hr

As shown in Table 1, both the invention example and the comparative example used the same welding material, the inner diameter of the pipe (P) was the same as 57mm, Inventive Example 1 and Comparative Example 1 is a 1000mm long pipe (P), Inventive example 2 and comparative example 2 overlay-welded the pipe P of 500 mm length, and inventive example 3 and the comparative example 3 welded the pipe P of 1500 mm length.

As shown in the above table, the same pipe was overlaid with the same welding material, and in the case of Inventive Example 1, it took about 7 hours. It took longer.

Similarly, in case of Inventive Example 2, it took about 4 hours, in case of Comparative Example 2, it took 6 hours, Inventive Example 3 took 10 hours, but in case of Comparative Example 3 it took 18 hours. As can be seen in Inventive Examples 1 to 3 and Comparative Examples 1 to 3, the longer the length of the pipe (P), it can be seen that the reduction ratio of the working time increases, which is a tandem overlay when the longer length overlay welding It can be seen that the welding method is more advantageous.

In addition, the present invention can reduce the time required for welding by about 40 to 50% compared to the conventional, it can exhibit almost twice the productivity.

Although the present invention has been described in detail with reference to the accompanying examples, the present invention is not limited to these examples.

In addition, although the present invention proposes a circular frame 140, the shape of the frame 140 may have other shapes without being limited thereto, and even though the shape of the frame 140 is partially open, the nozzle connecting members 120a to d may be moved. If you can do it.

In addition, in the present invention, the first and second welding torches 430 and 440 are described as being connected to the respective booms 410 and 420, but a plurality of welding torches may be mounted to a single boom.

P: pipe
100: cooling unit 101: cooling unit main body
110a ~ h: nozzle 110 ~ 115: nozzle row
120a to d: nozzle connection parts 130 and 160: cooling water connection part
140: frame 150: nozzle moving part
200: temperature sensor 210: water tank
220: pump 230: quantity control valve
235: distribution valve 240: cooling tower
300: control unit 410, 420: boom
430, 440: welding torch 450: main body

Claims (8)

Pipe rotating unit for rotating the pipe; And
A weld for overlay welding the inner surface of the pipe inside the pipe,
The welding portion boom is mounted to the end a plurality of welding torch; A main body connected to the boom and moving the boom; And a cooling unit surrounding the pipe.
A plurality of welding torch mounted to the boom is spaced apart a predetermined distance in the pipe longitudinal direction with respect to each other,
The plurality of welding torches includes a first welding torch for overlay welding to a pipe and a second welding torch for overlay welding to a weld layer by the welding torch,
The first welding torch and the second welding torch are spaced 50 to 150 mm in the longitudinal direction of the pipe,
The cooling unit includes a plurality of nozzles arranged in a plurality of rows disposed along a circumferential direction of the pipe to cool between at least an area corresponding to the second welding torch rear end from an area corresponding to the position of the first welding torch,
The cooling unit includes:
A nozzle connector connecting at least one of the plurality of nozzles disposed along the circumferential direction of the pipe; And a nozzle moving part connected to the nozzle connecting part to move the nozzle connecting part in a radial direction of the pipe, wherein the nozzle moving part is capable of moving the nozzle connecting part in the radial direction of the pipe according to the diameter of the pipe. Overlay welding device. delete delete delete delete The method of claim 1,
The cooling unit is provided with a moving means, the tandem overlay welding apparatus, characterized in that the cooling unit is moved together with the movement of the main body for moving the welding torch. The method of claim 1,
The nozzle connector is divided into two or more with the same angle along the circumferential direction of the pipe,
And wherein the number of nozzles connected to the nozzle connection towards the pipe passing through the welding torch is greater than the number of nozzles connected to the nozzle connection towards the pipe through the welding torch. The method of claim 1,
The cooling unit
A water tank for collecting the cooling water used in the lower portion of the pipe;
A pump for supplying the cooling water collected in the tank back to the nozzle;
A non-contact temperature sensor mounted on each welding torch and measuring the temperature of the pipe being rotated to the position of each welding torch;
And a control unit connected to each of the non-contact temperature sensors to control a quantity control valve and / or a dispensing nozzle provided between the nozzle and the water tank to adjust the amount of cooling water injected into the pipe. Welding device.

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