KR100607338B1 - The plasma automatic welding machine with welding seam tracking and plate fit-up device for the fabrication of membrane type lng(liquified natural gas) carrier ship containment tank - Google Patents

Abstract

The present invention relates to a plasma automatic welding device for the cargo-drying of a membrane type LNG carrier having a welding line tracking and member mounting device,

 To improve the welding quality of special zones generated in the membrane type cargo hold structure, and to provide the plasma welding method and the device equipped with the equipment to maintain the welding speed very high and to track the welding line and attach the member at the same time. To improve the welding quality and to improve the productivity.

The present invention for achieving the above object is a carriage installed in the welding device of the thin plate overlapping portion of the in-bar tube and the anchoring bar of the membrane-type LNG carrier cargo hold structure, and installed so as to be able to adjust the height on the carriage. A welding head which receives power from a plasma welding device to perform welding, a welding torch installed at the welding head to form a welding bead, and a member installed at one side of the lower portion of the welding head to press and mount the invar tube and the anchoring bar. A welding line tracking device installed on the other side of the lower portion of the welding head and having a contact edge contacting one end of the overlapping joint of the thin plate to induce a moving direction of the welding torch, and installed on the carriage and connected to the welding head. A soup that always keeps the welding head in the inva tube direction And the regulator, characterized in that the sphere consists of technical base.

LNG carrier, CS-1, cargo hold, invar tube, anchoring bar, lamination joint welding, plasma welding, mounting, welding line tracking, member pressurizing device

Description

The plasma automatic welding machine with welding seam tracking and plate fit-up device for the fabrication of membrane type LNG (Liquified Natural Gas) ) carrier ship containment tank}

1 is a perspective view showing a part of a membrane type cargo hold structure to which the present invention is applied in three dimensions;

2 is a cross-sectional view of the welded portion to which the present invention is applied;

3 is a perspective view showing the configuration of the device according to the invention,

Figure 4 is a side view showing a state in which the welding line tracking and member mounting apparatus according to the present invention is applied,

5 is a block diagram of a system for applying the plasma welding technique according to the present invention,

6 is a detailed side cross-sectional view of the welding head, rail and carriage of the present invention;

7 is a bottom view of a weld head portion of the invention.

<Description of the symbols for the main parts of the drawings>

(11): Invar Tube

(12): Transversal Bulkhead

(13): Anchoring Bar

(14): Lap Joint (15): Working Angel

(21): Rail (22): Carriage

(23): Spring Adjustment Device

(24): Welding Head

24a: welding head socket 24b: welding torch fixing

(25): Welding Bead Width (26): Handle

(31): Welding Torch

(32): Plate Pressing Device

(33): Welding Seam Tracking Device

400: plasma welding apparatus

(41): plasma power source

(42) Plasma Gas Tank

(43): Shielding Gas Tank

(44): Controller (45): Interface

(46): Remote Controller

The present invention relates to an automatic plasma welding device for welding overlapping seams of different steel sheets generated during cargo drying of a LNG carrier, for welding special zones generated in the cargo hold structure of a membrane type LNG carrier. It is possible to simultaneously perform mounting and welding of overlapping seam sheets of different materials, and relates to an apparatus for automatically performing plasma welding without a separate welding line tracking device.

In general, welding involves joining two metal materials to be joined, namely, a base metal to be melted or semi-melted, and joining only the base metal or by fusion of the base metal and the filler metal. Arc welding, gas welding, thermite welding, and electroslag In the case of arc welding, the welding is classified into a consumable in which the electrode is consumed according to whether the electrode is consumed, and a non-consumable welding method in which the electrode is not consumed. Among them, representative welding techniques of non-consumable welding methods include gas tungsten arc welding (GTAW) and plasma welding, and are classified into manual or automatic welding according to their unique characteristics and uses. can do.

The gas tungsten arc welding is a welding method of melting and bonding a base material by arc heat generated between a non-consumable electrode tungsten electrode and a base material while using an inert gas such as Ar and He as a shield gas. It is also supplied and melted together with the base metal. The protective gas is called TIG (Tungsten Inert Gas) welding because Ar or He, which is an inert gas, is used to prevent oxidation of the base metal and the tungsten electrode rod. This welding method can be applied to all welding postures, and it is used when welding of materials sensitive to oxidation or nitriding or low heat input high quality construction is required because the arc is very stable and the weld quality is excellent.

The plasma arc welding is a welding method using a plasma jet which is ejected at high speed, and may be referred to as a special form of TIG welding. In plasma welding, plasma gas is separately supplied in addition to the protective gas, and the tungsten electrode is positioned inside the water-cooled shrinkage nozzle. The characteristic of this welding method is that since the arc is contracted by the shrinkage nozzle and has a cylindrical shape, the area of the base material portion subjected to the arc heat source hardly changes even if the distance between the nozzle and the base material changes. After all, plasma arc welding is almost the same as the TIG welding process except that the arc concentration is improved by the shrinkage nozzle.

Conventionally, among the above welding methods, the TIG welding method, which is relatively easy in configuration, control, signal transmission, etc. of equipment, is mainly used in the overlapping joint. However, the TIG welding has a disadvantage in that productivity cannot be increased because the welding speed is slower than that of the plasma welding method.

In addition, for welding overlapping seam of different materials, it is necessary to precisely maintain the direction of the welding line and the torch so that the direction of welding torch does not change during welding, and to prevent the gap between the overlapping seam from occurring. It must be closely contacted to obtain a good welding quality. In other words, if the posture of the welding torch is incorrect or the welding condition is not proper, the desired welding bead is not generated due to excessive heat input, insufficient heat input, or a welding defect frequently occurs. Therefore, a stable plasma welding condition should be set.

In addition, separate welding work is required to attach different steel sheets when welding by hand or by machine, and verification work is required to guide welding torch along the welding line during welding, or separate electrical sensor and The control method requires mechanical complexity and frequent hands-on operation and maintenance.

The present invention is created to solve the above conventional problems,

It is possible to improve the welding quality of special zones generated in the membrane type cargo hold structure, and to provide great efficiency with the plasma welding device equipped with the equipment to simultaneously track the welding seam and to install the members to keep the welding speed very high. The purpose.

The present invention to achieve the object as described above and to remove the drawbacks of the prior art, the present invention is a membrane type liquefied natural gas carrier ship having a seam tracking and member mounting device of the laminate overlap of the in-bar tube and anchoring bar In the plasma automatic welding device,

A carriage installed to be transported on a rail, a welding head installed to be capable of adjusting the height of the carriage to receive power from a plasma welding device, and a welding torch installed at the welding head to form a welding bead; A member pressurizing device installed at one side of the lower welding head to press and install the invar tube and the anchoring bar, and a contact edge installed at the other side of the lower welding head to contact one end of the overlapping joint of the thin plate. Weld line tracking device for guiding the direction of movement and the spring adjustment mechanism is installed on the carriage and connected to the welding head to keep the welding head in close contact with the inva tube direction.

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

Figure 1 is a perspective view showing a part of the membrane type cargo hold structure to which the present invention is applied in three dimensions. As shown in FIG. 1, the inva tube 11 is a structure composed of 1.5 mm thick thin plated Invar steel, and meets the anchoring bar 13, which is an 8 mm thick stainless steel plate attached perpendicularly to the transverse bulkhead 12. The overlap welding part 14 generate | occur | produces in a site | part.

Figure 2 shows the welded portion shown in Figure 1 from the side.

In the overlap welding portion 14 shown in FIG. 1, the working angle 15 for welding and the access of the torch for plasma automatic welding is formed to make uniform welding beads.

The working angle 15 is an acute angle of about 60 degrees.

A welding torch enters the working angle 15 to be welded, but it can be seen that the working angle 15 space that can be welded is very narrow due to the blocking of the transverse bulkhead 12.

3 is a perspective view showing the configuration of the apparatus according to the present invention. As shown in FIG. 3, a rail 21 for welding, a carriage 21 which can be transported in the traveling direction from the rail 21 to the overlapping joint welding portion, and a spring adjustment mechanism in the center of the carriage 21. 23 is provided, and the welding head 24 is spanned by the spring adjustment mechanism 23. The welding head 24 is composed of a welding head socket 24a and a welding torch fixing part 24b. 24a) Turn the handle 26 installed on the top to raise the screw to adjust the height, and the welding line tracking to track the member pressing device 32 and the welding line to pressurize the working member without a separate control method The apparatus 33 is comprised. In order to automatically drive the carriage 22 in the welding direction on the rail 21, an electric or air operated motor may be used. In addition, a clamp / unclamp mechanism may be provided between the rail 21 and the carriage 22 for the attachment / detachment of the system. 4, the member pressurizing device 32 and the welding line tracking device 33 are attached together as shown in FIG. 4, and the member pressing device 32 and the welding line tracking device 33 are connected in the welding direction. It consists of a roller for traveling, and is installed inclined in the welding line direction, and the torch for plasma welding is located in it. (The welding line tracking device has an inclination of about 1 degree to about 90 degrees.)

The spring adjustment mechanism 23 for tracking the position in the weld bead width 25 direction for the welding line tracking is provided. Combination of compression and tension spring is configured to be always in contact with the direction of the inva tube (11).

5 is a block diagram of a system for applying the plasma welding technique according to the present invention.

The carriage 22 for moving the plasma welding torch 31, the rail 21 for moving the carriage 22, the plasma welding machine 41 for supplying welding power to the plasma welding torch 31, and the plasma welding machine ( 41 and the plasma gas storage unit 42 and the protective gas storage unit 43 connected to the welding torch 31 and the controller 44 and the controller 44 connected to the plasma welding machine 41 and the carriage 22. It is configured to include an interface unit 45 and a remote control 46 and the like connected to.

Effects of the present invention having the configuration as described above are as follows.

The overlap welds 14 are created to join the invar tube 11 and the anchoring bar 13 at the working angle 15 to make uniform weld beads for welding to the overlap welds 14. Welding work is required.

However, since the transverse bulk head 12 is vertically erected at the working angle 15 to form a narrow space, the welding working environment is poor.

Thus, the rail 21 is provided on the ship structure along the welding portion, and the welding is possible to adjust the height of the up and down by attaching to the carriage 22 and the carriage 22 installed to be movable in the rail driving direction on the rail 21. The head 24 is configured and a spring adjusting mechanism 23 is provided at the connection portion between the carriage 22 and the welding head 24 to move in the direction of the welding bead width 25 to perform welding. The welding head 24 creates an environment in which the working angle 15 can be welded.

As shown in FIG. 6, the welding head 24 rotates the handle 26 in a manual structure in which the whole body is moved in accordance with the screw rotation of the main body to be screwed up and down. The height is adjusted by rolling up the welding head socket 24a.

A welding line tracking device 33 capable of automatically tracking the welding line is installed on the welding head 24, so that no additional adjustment is required for the welding torch 31, and the welding torch 31 is pressurized by a press roller. The device 32 is installed to form the overlap welding portion 14, which is a portion to be welded by pressing the invar tube 11 and the anchoring bar 13, and the weld bead tracking device 33 in the direction of the weld bead width 25 The automatic tracking due to the compression and tension of the spring adjustment mechanism 23 to implement the welding to the welding torch 31 to the overlapping welding portion (14).

When the positional relationship between the welding torch 31 attached to the lower end of the welding head 24, the member pressing device 32, and the welding line tracking device 33 is viewed from the bottom as shown in FIG. As follows.

The welding torch 31 is located below the center of the welding head 24 when the welding head 24 is viewed upward while the anchoring bar 13 is set to the right and the invar tube 11 is set to the left. It is attached, the welding line tracking device 33 is installed on the welding torch 31, the member pressing device 32 is installed on the left side of the welding line tracking device 33, the member pressing device 32 When the roller inclined to the left of the mounting plate moves toward the left side in the advancing direction, welding is performed due to the restraint of the welding line tracking device 33 provided with a contact edge contacting one end of the overlapping plate portion 14. The head 24 advances in the welding progress direction along the welding line, followed by the welding line tracking device 33, and the welding torch 31 forms welding beads along the welding line.

In addition, the welding head 24 is provided with a plasma welding machine 41 to generate a stable welding bead and implement a high welding speed.

The welding line tracking device 33 is a function that allows the pressurized roller to be in close contact with the overlapping portion of the welding member by a mechanical guide method, and maintains a state in which it is bent toward the inner side in the roller direction along the welding line and exits in the guide direction. At this time, the spring adjustment mechanism 23 is provided with a tension spring for smooth operation in the bending direction of the welding line tracking device 33 perpendicular to the traveling direction and return to the original position after the operation.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

The effect of the present invention can be expected by the above-described configuration and action,

In the automatic welding of overlapping joints of different thin plates in the cargo structure of GTT membrane type liquefied natural gas carriers, it is possible to simultaneously install the workpiece and trace the welding line without the member mounting work, and to enable high-speed welding using plasma welding technique. To reduce the welding defects and to obtain high productivity, the invention is a useful invention having a great advantage, which is expected to be used in industry.

Claims (3)

In the welding device of a thin-lap joint of a membrane type LNG carrier carrying structure, A carriage 22 installed to be transported on the rail 21; A welding head 24 installed on the carriage 22 to adjust the height and receiving power from the plasma welding apparatus 400 to perform welding; A welding torch 31 installed at a lower end of the welding head 24 to form a welding bead; A member pressurizing device (32) installed at one side of the lower end of the welding head (24) to press and mount the invar tube (11) and the anchoring bar (13); A welding line tracking device (33) installed at the lower end of the welding head (24) to guide the moving direction of the welding torch (31) by having a contact edge contacting one end of the thin-lap overlapping portion (14); Welding line tracking, characterized in that consisting of a spring adjustment mechanism 23 is installed on one side of the carriage 22 and connected to the upper end of the welding head 24 to keep the welding head 24 in close contact with the invar tube 11 direction. And a plasma type automatic welding apparatus for drying a membrane type LNG carrier cargo hold provided with a member mounting device. The method of claim 1; The lamination joint is a plasma automatic welding device for drying the cargo container tracking cargo tank equipped with a membrane type LNG carrier, characterized in that the overlapping joint of the Invar tube (11) and the anchoring bar (13). The method of claim 1 or 2; The member pressurizing device 32 is a pressure roller, in which the steering of the roller is inclined at a predetermined angle in the direction of movement of the welding line tracking device 33 and the invar tube 11, and thus, the welding line tracking device 33 is applied as the welding progresses. A plasma type automatic welding apparatus for dry cargo hold of a membrane type LNG carrier having a welding line tracking and a member mounting device, characterized in that the tracking is generated.

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