Auxiliary welding tool for strake lap joint plate of liquid cargo tank of LNG ship and using method

Abstract

The invention discloses a liquefied natural gas (LNG) ship liquid cargo tank strake lap joint plate welding auxiliary tool which comprises a fastening clamp, a clamping device and a connecting hole. Connecting structures matched with the fastening clamp connecting holes are arranged at the two ends of the connecting rod, the connecting rod is detachably connected with the fastening clamp, and at least one through hole is formed in the surface of the connecting rod. The adjusting mechanism penetrates through the through hole in the surface of the connecting rod to be connected with the connecting rod and can move up and down in the connecting rod through hole. And the fixing plate is arranged above the lapping plate and can be tightly pressed on the lapping plate through an adjusting mechanism. According to the auxiliary tool, weld penetration and deformation of the lap joint plate in the welding process can be avoided, or a deformed weld joint area is repaired, operation is easy, welding efficiency is high, by means of the auxiliary tool, the welding quality of the strake lap joint plate can be better controlled, and favorable conditions are created for smooth development of the next procedure.

Description

Technical Field

[0001] The invention relates to the field of technical construction of liquid cargo tanks of LNG ships, and in particular to an auxiliary tool for welding lap plates of strakes of liquid cargo tanks of LNG ships and a use method thereof. Background Art

[0002] The welding of strake lap plates is one of the most common welding contents in the liquid cargo tank of LNG carriers. The welding of strake lap plates uses automatic welding and manual welding. Automatic welding uses special equipment for welding, which is mainly used for welding the middle part of the lap plate. Since some strake lap plates have defects in the automatic welding welds, or the weld area is deformed, manual welding is required for repair. Manual welding is used for positions that cannot be completed by automatic welding, or to repair defects caused by automatic welding. Because the thickness of the lap plate is only 1.0mm, and the thickness of the strake welded to it is only 0.7mm, it is very easy to produce defects such as weld penetration and deformation during the welding process, which does not meet the weld quality requirements. At present, the welding speed can only be controlled and the welding is performed in sections, and the next welding can be performed after the weld is completely cooled, but the effect is very small, the construction period is long, and the weld penetration and deformation cannot be completely avoided. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides an auxiliary tooling and use method for welding lap plates of liquid cargo tank strakes of LNG ships, which can shorten the construction period, ensure the quality of welds, and avoid weld penetration and deformation.

[0004] The object of the present invention is achieved through the following technical solutions: an auxiliary tool for welding lap plates of LNG tank strakes, comprising:

[0005] The fastening clamp comprises a clamping device and a connecting hole.

[0006] The connecting rod has connecting structures matched with the connecting holes of the fastening clamp at both ends, and is detachably connected to the fastening clamp. The surface of the connecting rod is provided with at least one through hole.

[0007] The adjusting mechanism is connected to the connecting rod through a through hole penetrating the surface of the connecting rod and can move up and down in the through hole of the connecting rod.

[0008] The fixing plate is arranged above the lap plate and can be pressed onto the lap plate by an adjusting mechanism.

[0009] Preferably, the fastening clamp comprises a clamping arm, a rotary handle, an eccentric wheel and a clamping body, wherein the clamping arm is connected to the clamping body via a bolt, and the rotary handle and the eccentric wheel are connected to the bolt.

[0010] Preferably, the connecting rod is a columnar structure with two threaded through holes provided thereon.

[0011] Preferably, the adjustment mechanism is an adjustment bolt.

[0012] Preferably, the connecting rod and the adjusting bolt are made of 304L stainless steel.

[0013] Preferably, the fixing plate is a heat dissipation block made of heat dissipation material.

[0014] In addition to providing an auxiliary tooling for welding lap joint plates of LNG tank strakes, the present invention further provides a method for using the auxiliary tooling to assist the manual welding process of lap joint plates of LNG tank strakes. The specific steps are as follows:

[0015] Step 1, assemble the connecting rod and the adjusting mechanism into one piece;

[0016] Step 2: Fix the fastening clips on the folded edges at both ends of the lap plate according to the weld position of the lap plate;

[0017] Step 3: Connect the connecting rod and the fastening clamp;

[0018] Step 4: Place the fixing plate above the weld, adjust the adjustment mechanism on the connecting rod, and press the fixing plate tightly above the lap plate;

[0019] Step 5: Weld or repair according to the welding process;

[0020] Step 6: After the welding work is completed and the weld area is cooled, remove the auxiliary tooling to complete the welding.

[0021] Preferably, in step 4, the fixing plate is placed 5 mm to 15 mm above the weld.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention provides an auxiliary tool for welding lap joint plates of LNG tank strakes and a method for using the tool, which presses the welding area to make the strakes fit closely with the reverse heat protection and the box to prevent the strakes from being welded through. The heat dissipation device can be provided to quickly absorb the heat generated by welding, avoid excessive oxidation and dryness of the welds due to secondary welding, eliminate stress in the welding area, avoid arching of the strakes, improve welding quality, and make the repair work more effectively completed.

[0024] The auxiliary tooling provided by the present invention can prevent the lap plate from being welded through and deformed during the welding process, or repair the deformed weld area. It is simple to operate and has high welding efficiency. By using the auxiliary device, the welding quality of the column plate lap plate can be better controlled, creating favorable conditions for the smooth implementation of the next process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the welding auxiliary tooling structure of the lap plate of the LNG tank strake in the embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the fastening clip structure in an embodiment of the present invention.

[0027] In the figure, 1 is a fastening clamp; 2 is a connecting rod; 3 is an adjusting bolt; 4 is a heat dissipation device; 5 is a clamping arm; 6 is a rotary handle; 7 is an eccentric wheel; and 8 is a clamp body. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0029] like Figure 1 As shown, the technical solution of the present invention provides an auxiliary tool for welding lap plates of LNG tank strakes, including:

[0030] A fastening clamp 1, comprising a clamping device and a connecting hole;

[0031] The connecting rod 2 has connecting structures at both ends that match the connecting holes of the fastening clip 1, and is detachably connected to the fastening clip 1. The surface of the connecting rod 2 is provided with at least one through hole;

[0032] The adjusting mechanism 3 is connected to the connecting rod 2 through a through hole passing through the surface of the connecting rod 2, and can move up and down in the through hole of the connecting rod 2;

[0033] The fixing plate 4 is arranged above the lap plate and can be pressed against the lap plate through the adjusting mechanism 3 .

[0034] like Figure 2 As shown, in one embodiment of the present invention, the fastening clamp 1 includes a clamping arm 5, a rotary handle 6, an eccentric wheel 7 and a clamping body 8, wherein the clamping arm 5 is connected to the clamping body 8 by bolts, and the rotary handle 6 and the eccentric wheel 7 are connected with bolts.

[0035] In one embodiment of the present invention, the connecting rod 2 is a columnar structure, and is provided with two threaded through holes.

[0036] In one embodiment of the present invention, the adjusting mechanism 3 is an adjusting bolt, and there is a fitting on the adjusting bolt for manual twisting. In this embodiment, the connecting rod 2 and the adjusting bolt are made of 304L stainless steel.

[0037] In one embodiment of the present invention, the fixing plate 4 is a heat dissipation block made of a heat dissipation material. The heat dissipation block can be selected in different sizes and materials according to the actual situation on site, such as a stainless steel block or a copper block.

[0038] In addition to providing an auxiliary tooling for welding lap joint plates of LNG tank strakes, the technical solution of the present invention further provides a method for using the auxiliary tooling to assist the manual welding process of the lap joint plates of LNG tank strakes. The specific steps are as follows:

[0039] Step 1, assemble the connecting rod 2 and the adjusting mechanism 3 into one body;

[0040] Step 2: According to the weld position of the lap plate, fix the fastening clip 1 on the folded edges at both ends of the lap plate;

[0041] Step 3, connecting the connecting rod 2 and the fastening clamp 1;

[0042] Step 4, place the fixing plate 4 above the weld, adjust the adjustment mechanism 3 on the connecting rod 2, and press the fixing plate 4 onto the lap plate;

[0043] Step 5: Weld or repair according to the welding process;

[0044] Step 6: After the welding work is completed and the weld area is cooled, remove the auxiliary tooling to complete the welding.

[0045] In one embodiment of the present invention, Figure 1 to Figure 2 The auxiliary tooling shown includes a fastener 1, a connecting rod 2, an adjusting bolt and a heat sink; the fastening clamp 1 includes a clamping arm 5, a rotary handle 6, an eccentric wheel 7 and a clamp body 8. The clamping arm 5 is connected to the clamp body 8 by a bolt. When working, the clamping arm 5 is moved close to the clamp body 6 by rotating the rotary handle 6. The connecting rod 2 is a columnar body with a middle length of 480mm and a diameter of 30mm, and a length of 30mm and a diameter of 10mm at both ends. Two threaded through holes are evenly distributed in the middle for installing adjusting bolts, and the heat sink is fixed above the lap plate by adjusting bolts. After using this tooling, it can ensure that the column plate is closely fitted with the reverse heat protection and the box during welding to prevent welding through, and it can quickly absorb the heat during welding to reduce deformation, while playing a rigid fixing role.

[0046] The above-mentioned tooling is used to assist the manual welding process of the lap plate welding of the LNG tank tank strake, which specifically includes the following steps:

[0047] Step 1, assemble the connecting rod 2 and the adjusting bolt together in advance;

[0048] Step 2: According to the weld position of the lap plate, fix the fastening clip 1 on the folded edges at both ends of the lap plate;

[0049] Step 3, connect the connecting rod 2 and the fastening clamp 1 together;

[0050] Step 4: Place the heat sink about 10 mm away from the weld, and tighten the adjusting bolt on the connecting rod 2 to press the heat sink;

[0051] Step 5: Weld or repair according to the welding process;

[0052] Step 6: After the welding work is completed and the weld area is cooled, the tooling can be removed.

[0053] The present invention provides an auxiliary welding tool and use method for the lap plate of the liquid cargo tank strake of an LNG ship, which can make the Invar plate fit tightly with the reverse heat protection and the box to prevent the Invar plate from being welded through, and can quickly absorb the heat generated by welding to release the stress in the welding area, thereby eliminating the deformation caused by thermal stress, and preventing the oxidation and withering caused by overheating of the weld. At the same time, it plays a rigid fixing role to prevent deformation. The present invention uses a special welding tool, which includes a fastening clamp, a connecting rod, an adjusting bolt, and a heat dissipation device. The fastening clamp is installed at both ends of the lap plate, the connecting rod is connected to the fastening clamp, and the adjusting bolt is installed on the connecting rod. The heat dissipation device is fixed above the lap plate by the adjusting bolt.

[0054] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An auxiliary tool for welding lap joint plates of LNG tank strakes, characterized in that: The auxiliary tooling includes: A fastening clamp (1), comprising a clamping device and a connecting hole; A connecting rod (2) having connecting structures at both ends thereof that cooperate with the connecting holes of the fastening clamp (1) and being detachably connected to the fastening clamp (1); and at least one through hole being provided on the surface of the connecting rod (2); An adjusting mechanism (3) is connected to the connecting rod (2) through a through hole passing through the surface of the connecting rod (2) and can move up and down in the through hole of the connecting rod (2); The fixing plate (4) is arranged above the lap plate and can be pressed against the lap plate by the adjusting mechanism (3).

2. The auxiliary tooling for welding the lap plate of the LNG tank strake according to claim 1, characterized in that: The fastening clamp (1) comprises a clamping arm (5), a rotary handle (6), an eccentric wheel (7) and a clamping body (8), wherein the clamping arm (5) is connected to the clamping body (8) via bolts, and the rotary handle (6) and the eccentric wheel (7) are connected to the bolts.

3. The auxiliary welding tool for lap joint plate of LNG tanker liquid cargo tank strake according to claim 2, characterized in that: The connecting rod (2) is a columnar structure and is provided with two threaded through holes.

4. The auxiliary tooling for welding lap joint plates of LNG tanker liquid cargo tank strakes as claimed in claim 3, characterized in that: The adjusting mechanism (3) is an adjusting bolt.

5. The auxiliary welding tool for lap joint plate of LNG tank strake according to claim 4, characterized in that: The connecting rod (2) and the adjusting bolt are made of 304L stainless steel.

6. The auxiliary welding tool for lap joint plate of LNG tank strake according to claim 5, characterized in that: The fixing plate (4) is a heat dissipation block made of heat dissipation material.

7. A method for using an auxiliary tool for welding lap joint plates of a LNG tanker's liquid cargo tank strake, characterized in that: The auxiliary tooling according to any one of claims 1 to 6 is used to assist the manual welding process of the lap plate welding of the LNG tank strake, and the specific steps are as follows: Step 1, assembling the connecting rod (2) and the adjusting mechanism (3) into one body; Step 2, according to the position of the weld of the lap plate, fix the fastening clip (1) on the folded edges at both ends of the lap plate; Step 3, connecting the connecting rod (2) and the fastening clamp (1); Step 4, placing the fixing plate (4) above the weld, adjusting the adjusting mechanism (3) on the connecting rod (2), and pressing the fixing plate (4) tightly above the lap plate; Step 5: Weld or repair according to the welding process; Step 6: After the welding work is completed and the weld area is cooled, the auxiliary tooling is removed to complete the welding.

8. The method for using the auxiliary tooling for welding the lap plate of the LNG tank strake according to claim 7, characterized in that: In step 4, the fixing plate (4) is placed 5 mm to 15 mm above the weld.

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