A measure to prevent deformation of bottom flange of small diameter stainless steel storage tank

Abstract

The present invention relates to the technical field of aerospace stainless steel tanks and discloses 1. a deformation prevention measure for a bottom flange of a small-diameter stainless steel tank, comprising the following steps: S1, fixing a tank bottom assembly; S2, evenly raising a manhole flange; S3, supporting the flange with a rigid tool to prevent positional changes; S4, symmetrically spot welding in quadrants I, II, III, and IV; S5, then symmetrically spot welding in the middle of the quadrants; S6, sequentially adopting similar symmetrical positioning methods to achieve a positioning welding point every 3-5 mm and symmetrically evenly distribute the spot welding; and S7, completing the welding, reducing deformation during flange welding, ensuring the shape and position dimensions of the flange, solving a series of problems caused by deviations in the shape and position dimensions, reducing welding stress, improving weld strength, reducing some uncertainties caused by profiling, reducing technical risks, and improving product quality.

Description

Technical Field

[0001] The invention relates to the technical field of aerospace stainless steel tanks, in particular to a deformation prevention measure for a bottom flange of a small-diameter stainless steel tank. Background Art

[0002] Due to the small diameter of the small diameter stainless steel storage tank, the flanges are too densely distributed on the bottom of the tank. The same as the common large diameter tank bottom is that the flange size is consistent, but the difference is that the distance and position of the distributed flanges are different. The large diameter tank bottom is evenly distributed, and the deformation is within the controllable range under the guarantee of the corresponding tooling. However, the traditional flange anti-deformation measures for the small diameter stainless steel tank bottom flange welding are ineffective. The bottom flanges of the tank are all butt flanges. The common problem of butt flange welding is sinking after welding. Reducing sinking can solve some deformation problems, but stress concentration is also one of the main causes of deformation. The traditional large diameter tank bottom cannot eliminate these factors at all. The generation of these problems has a great impact on the subsequent pipeline sampling. Severe deformation can lead to the scrapping of a large number of prefabricated pipelines, and at the same time, it makes pipeline sampling very difficult. Summary of the Invention

[0003] (1) Technical problems solved

[0004] In view of the deficiencies of the prior art, the present invention provides a deformation prevention measure for a bottom flange of a small-diameter stainless steel storage tank.

[0005] (2) Technical solution

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a deformation prevention measure for the bottom flange of a small-diameter stainless steel storage tank, comprising the following steps:

[0007] S1. Fix the bottom assembly of the box;

[0008] S2. Raise the manhole flange evenly;

[0009] S3. Use rigid tooling to support and prevent position changes;

[0010] S4. Perform spot welding symmetrically in quadrants I, II, III, and IV respectively;

[0011] S5, then spot weld symmetrically in the middle of the quadrant;

[0012] S6. Use similar symmetrical positioning methods in sequence to achieve a positioning welding point every 3-5mm, and symmetrically distribute the spot welding;

[0013] S7. Complete welding.

[0014] Preferably, S1 specifically comprises: setting up two platforms, namely platform A and platform B, both of which are provided with pressing fixtures, and fixing the box bottom assembly on platform A and platform B by the pressing fixtures.

[0015] Preferably, S2 is specifically as follows: a stainless steel convex hole flange tooling is made on the box bottom assembly, a manhole flange is placed on the upper end of the convex hole flange tooling and on the box bottom assembly, the convex hole flange tooling and the manhole flange are welded to the box bottom assembly, and a manhole cover is fixed to the manhole flange by bolts.

[0016] Preferably, the diameter of the convex hole flange tooling is smaller than that of the manhole flange, the convex hole flange tooling is evenly processed, spot-welded evenly and symmetrically, and has a hollow structure.

[0017] Preferably, a pad is placed on the A platform, a jack is fixedly mounted on the pad, a support plate is fixed on the output end of the jack, the support plate and the convex hole flange tooling are evenly spot welded, and the convex hole flange tooling and the manhole flange are pushed up a certain distance by the jack to achieve a uniform lifting effect, uniformly lifting mm, and uniform force is applied during the ejection process to prevent damage to the product caused by excessive force.

[0018] Preferably, two small flanges are fixedly installed on the side of the box bottom assembly to manufacture a simple flat tooling, and the upper and lower surfaces of the small flanges are connected by bolts to ensure their profile. The small flange is installed with a flange cover, and two vertical ribs, namely triangular reinforcement ribs, are spot welded in the triangular area between the manhole flange and the two small flanges on one side to strengthen the rigidity of the triangular area and reduce the stress deformation caused by welding.

[0019] Preferably, a jack at the triangular rib is also placed on the pad, the output end of the jack at the triangular rib is connected to the triangular reinforcement rib, and the triangular reinforcement rib is supported by the jack at the triangular rib, and the force points are selected during the supporting process to ensure uniform force.

[0020] Preferably, after the above measures are completed, subsequent welding work is started. The manhole flange is welded first, and the base welding is performed symmetrically in sections. When welding, single-sided welding and double-sided forming are ensured. A small current is used for welding, and the current is controlled at 80-100A. After welding, it is slowly cooled to room temperature to control the interlayer temperature. The small flange is welded using the same measures, and the cover is welded in the same way to complete the welding.

[0021] (3) Beneficial effects

[0022] Compared with the prior art, the present invention provides a deformation prevention measure for the bottom flange of a small-diameter stainless steel storage tank, which has the following beneficial effects:

[0023] 1. The anti-deformation measures for the bottom flange of the small-diameter stainless steel tank can reduce the deformation during the flange welding process, ensure the shape and size of the flange, solve a series of problems caused by the deviation of shape and size, reduce welding stress, improve weld strength, reduce some uncertainties caused by correction, reduce technical risks and improve product quality.

[0024] 2. The anti-deformation measures for the small-diameter stainless steel tank bottom flange ensure that the overall shape and dimensions are guaranteed. Within the reasonable tolerance range, the flange deformation is smaller than before. Because the overall shape and dimensions are well guaranteed, the required dimensions can be maintained without the need for post-weld adjustment, reducing the various risks associated with adjustment. The guaranteed shape and dimensions significantly reduce the workload for subsequent rocket assembly, significantly reducing time and cycle costs, and achieving significant results in terms of economic benefits and quality.

[0025] 3. The anti-deformation measures for the bottom flange of the small-diameter stainless steel tank were taken. The measured data after welding showed that the manhole flange was 4mm lower than the theoretical height. The height after welding was 10mm lower than the theoretical height before the measures were taken, reducing the error by 6mm. The overall surface changed more evenly after welding, and there was no wave deformation as before the measures were taken. The measures achieved the expected purpose. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of welding of the present invention.

[0027] In the figure: 1-box bottom assembly, 2-manhole flange, 3-manhole cover, 4-support plate, 5-convex hole flange tooling, 6-small flange, 7-flange cover, 8-triangular reinforcement rib, 9-jack at triangular rib, 10-jack, 11-pad, 12-A platform, 13-B platform, 14-pressing tooling. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] See also Figure 1 1. A small diameter stainless steel tank bottom flange anti-deformation measure, characterized in that it includes the following steps:

[0030] S1, fix the box bottom assembly 1;

[0031] S2. Raise the manhole flange 2 evenly;

[0032] S3. Use rigid tooling to support and prevent position changes;

[0033] S4. Perform spot welding symmetrically in quadrants I, II, III, and IV respectively;

[0034] S5, then spot weld symmetrically in the middle of the quadrant;

[0035] S6. Use similar symmetrical positioning methods in sequence to achieve a positioning welding point every 3-5mm, and symmetrically distribute the spot welding;

[0036] S7. Complete welding.

[0037] S1 specifically includes: setting up two platforms, namely platform A 12 and platform B 13 , both of which are provided with pressing fixtures 14 , and fixing the box bottom assembly 1 on the platform A 12 and the platform B 13 through the pressing fixtures 14 .

[0038] S2 is specifically as follows: a stainless steel convex hole flange tooling 5 is made on the box bottom assembly 1, and a manhole flange 2 is placed on the upper end of the convex hole flange tooling 5 and on the box bottom assembly 1. The convex hole flange tooling 5 and the manhole flange 2 are welded to the box bottom assembly 1, and a manhole cover 3 is fixed to the manhole flange 2 by bolts.

[0039] The diameter of the convex hole flange fixture 5 is smaller than that of the manhole flange 2. The convex hole flange fixture 5 is evenly processed and spot-welded symmetrically, and has a hollow structure.

[0040] A pad 11 is placed on the A platform 12, and a jack 10 is fixedly installed on the pad 11. A support plate 4 is fixed on the output end of the jack 10. The support plate 4 and the convex hole flange tooling 5 are evenly spot welded, and the convex hole flange tooling 5 and the manhole flange 2 are pushed up a certain distance by the jack 10 to achieve a uniform lifting effect, which is evenly lifted by 1 mm. Uniform force is applied during the ejection process to prevent damage to the product caused by excessive force.

[0041] Two small flanges 6 are also fixedly installed on the side of the box bottom assembly 1 to manufacture a simple flat tooling. The upper and lower surfaces of the small flanges 6 are connected by bolts to ensure their profile. The small flanges 6 are installed with flange covers 7. Two vertical ribs, namely triangular reinforcement ribs 8, are spot welded in the triangular area between the manhole flange 2 and the two small flanges 2 on one side to strengthen the rigidity of the triangular area and reduce the stress deformation caused by welding.

[0042] A triangular rib jack 9 is also placed on the pad 11. The output end of the triangular rib jack 9 is connected to the triangular reinforcement rib 8, and the triangular reinforcement rib 8 is supported by the triangular rib jack 9. During the supporting process, the force points are selected to ensure uniform force.

[0043] After completing the above measures, start the subsequent welding work. First weld the manhole flange 2, and weld the base symmetrically in sections. When welding the base, ensure single-sided welding and double-sided forming. Use a small current for welding, and control the current at 80-100A. After welding, slowly cool to room temperature to control the interlayer temperature. Use the same measures to weld the small flange 2, and the cover surface to complete the welding.

[0044] When in use, first raise the manhole flange 2 evenly by 1mm, and use a hard tooling to support it from below to prevent the position from changing. Perform spot welding symmetrically in quadrants I, II, III, and IV, and then perform spot welding symmetrically in the middle of the quadrant. Use similar symmetrical positioning methods in sequence to achieve a positioning welding point every 3-5mm, and perform spot welding symmetrically. Then place the box bottom assembly 1 between the two square platforms, use a special pressure block to press the pressure block on the fork ring step by bolting, tighten the pressure plate bolts to fix the box bottom on the two platforms, and make a stainless steel convex hole flange tooling 5, straight The diameter is smaller than that of the manhole flange 2, and the convex hole flange tooling 5 needs to be processed evenly. The convex hole flange tooling 5 is welded at the lower end point of the manhole flange 2, and the spot welding is evenly distributed and symmetrical to make it evenly stressed. Since the convex hole is a hollow structure, a supporting plate 4 is evenly spot welded under the convex hole as a stress point, and then the manhole cover 3 and the manhole flange 2 are fixed with bolts to reduce the deformation of the manhole during the welding process. According to the two 5mm arc-shaped stainless steel plates under the profile of the bottom of the box, two vertical ribs are spot welded in the triangular area between the manhole flange 2 and the two small flanges 6 on one side to strengthen the rigidity of the triangular area and reduce the stress deformation caused by welding. A jack 10 is used under the manhole flange 2 to push the manhole flange 2 up a certain distance. During the pushing process, force is applied evenly to prevent damage to the product caused by excessive force. Subsequently, the triangular reinforcement 8 is used to support it with a jack 9 at the triangular reinforcement. During the pushing process, a good force point is selected to make it evenly stressed. A simple flat tooling is manufactured, and the upper and lower surfaces of the small flange 6 are connected by bolts to ensure its profile. After the above measures are completed, subsequent welding work is started. First, the manhole flange 3 is welded, and the bottom welding is performed symmetrically in sections. When bottoming, single-sided welding and double-sided forming are ensured. A small current is used for welding, and the current is controlled at 80-100A. After welding, it is slowly cooled to room temperature to control the interlayer temperature. The cover is welded in the same way, and the small flange 6 is welded with the same measures. The measured data after welding show that the manhole flange 2 is 4mm lower than the theoretical height. The height after welding before and after no measures are taken is 10mm lower than the theoretical height, reducing the error of 6mm. After welding, the overall profile changes more evenly, and there is no wave deformation before no measures are taken. The measures achieve the expected purpose.

[0045] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A deformation prevention measure for the bottom flange of a small-diameter stainless steel storage tank, characterized by: The following steps are involved: S1. Fix the box bottom assembly (1); S2. Raise the manhole flange (2) evenly; S2 specifically comprises: making a stainless steel convex hole flange fixture (5) on the box bottom assembly (1); placing a manhole flange (2) on the upper end of the convex hole flange fixture (5) and on the box bottom assembly (1); the convex hole flange fixture (5) and the manhole flange (2) are welded to the box bottom assembly (1); and a manhole cover (3) is fixedly mounted on the manhole flange (2) by bolts; The diameter of the convex hole flange fixture (5) is smaller than that of the manhole flange (2), the convex hole flange fixture (5) is evenly processed, spot-welded evenly and symmetrically, and has a hollow structure; A pad (11) is placed on the A platform (12), a jack (10) is fixedly mounted on the pad (11), a support plate (4) is fixed on the output end of the jack (10), the support plate (4) and the convex hole flange fixture (5) are evenly spot welded, and the convex hole flange fixture (5) and the manhole flange (2) are pushed upward by a certain distance through the jack (10) to achieve a uniform lifting effect, uniformly lifting (1) mm, and applying force evenly during the ejection process to prevent damage to the product caused by excessive force; S3. Use rigid tooling to support the workpiece to prevent position changes. S4. Perform spot welding symmetrically in quadrants I, II, III, and IV. S5, then spot weld symmetrically in the middle of the quadrant; S6. Use similar symmetrical positioning methods in sequence to achieve a positioning welding point every 3-5 mm, and symmetrically distribute the spot welding; S7. Complete the welding.

2. The anti-deformation measure for the bottom flange of a small-diameter stainless steel storage tank according to claim 1, characterized in that: S1 specifically comprises: setting up two platforms, namely platform A (12) and platform B (13), both of which are provided with a pressing tool (14), and fixing the box bottom assembly (1) on the platform A (12) and the platform B (13) by the pressing tool (14).

3. The anti-deformation measure for the bottom flange of a small-diameter stainless steel storage tank according to claim 2, characterized in that: Two small flanges (6) are fixedly installed on the side of the box bottom assembly (1) to manufacture a simple flat tool. The upper and lower surfaces of the small flanges (6) are connected by bolts to ensure the profile. The small flanges (6) are installed with flange covers (7). Two vertical ribs, i.e., triangular reinforcement ribs (8), are spot-welded in the triangle zone between the manhole flange (2) and the two small flanges (2) on one side to strengthen the rigidity of the triangle zone and reduce the stress deformation caused by welding.

4. The anti-deformation measure for the bottom flange of a small-diameter stainless steel storage tank according to claim 3, characterized in that: A jack (9) at the triangular rib is also placed on the pad (11), and the output end of the jack (9) at the triangular rib is connected to the triangular reinforcement rib (8), and the triangular reinforcement rib (8) is supported by the jack (9) at the triangular rib, and the force points are selected in the supporting process to make it evenly stressed.

5. The anti-deformation measure for the bottom flange of a small-diameter stainless steel storage tank according to claim 4, characterized in that: After the above measures are completed, the subsequent welding work begins. First, the manhole flange (2) is welded, and the bottom welding is performed symmetrically in sections. When performing the bottom welding, single-sided welding and double-sided forming are ensured. A small current is used for welding, and the current is controlled at 80-100A. After welding, it is slowly cooled to room temperature to control the temperature between layers. The small flange (2) is welded using the same measures, and the cover surface is welded using the same method to complete the welding.

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