CN114054932B - Vertical assembly method for butt joint circular seam of spherical crown box bottom and short shell - Google Patents

Abstract

The invention provides a spherical crown box bottom and short shell butt joint circular seam vertical assembly method, which comprises the following steps: s1, hoisting a box bottom assembly to a circular seam membrane tire; s2, installing a fork-shaped ring pressing mechanism; s3, hoisting the welding plate assembly to the interior of the fork-shaped ring groove; s4, hoisting the short shell to the circular seam membrane tire; s5, hoisting a short shell compaction tool; s6, adjusting the internal and external supporting quantity of the welding backing plate and the roundness of the welding seam; s7, welding; s8, dismantling the compaction tool; s9, dismantling a welding backing plate; s10, taking out flash on the surface of the welding seam and polishing the welding seam; s11, detecting the welding seam phased array. The invention provides a spherical crown tank bottom and short shell butt joint circumferential seam vertical assembly method, which provides a 5m diameter tank bottom and short shell butt joint circumferential seam vertical assembly friction stir welding concept, develops a tank bottom and short shell vertical assembly process method for a 5m diameter tank, and realizes the assembly friction stir welding of a 5m large diameter tank bottom and short shell in a vertical state for the first time.

Description

Vertical assembly method for butt joint circular seam of spherical crown box bottom and short shell

Technical Field

The invention belongs to the technical field of aerospace equipment, and particularly relates to a spherical crown box bottom and short shell butt joint circular seam vertical assembly method.

Background

The friction stir welding technology is a revolutionary welding technology since the advent of a laser welding technology, fundamentally solves the problem of welding defects of aluminum alloy materials, and is a non-melting solid phase connection technology with green, high efficiency, high quality, small post-welding deformation and low residual stress. The friction stir welding technology generates friction heat through the contact of a stirring head rotating at a high speed and a workpiece, the friction heat enables the workpiece material to reach a molding state, the workpiece material in the molding state fills a cavity formed at the rear of a stirring pin under the combined use of the high-speed rotation and the advancing of the stirring head, and a complete welding joint is formed under the extrusion and stirring actions of a shaft shoulder and the stirring pin. The friction stir welding technology is successfully applied to the welding manufacturing process of the barrel section structure of a new generation carrier rocket and an active carrier rocket at present, and along with the engineering application research and development of the friction stir welding technology, the key technical attack and the upgrading application of an assembly welding equipment platform, the friction stir welding technology is also more and more widely applied to the important national aerospace engineering.

The spherical crown bottom transition ring of the carrier rocket is positioned at the bottom of the tank bottom, the cross section shape of the transition ring is shown in fig. 1, and the transition ring comprises three welding ends: the section end of the connecting cylinder, the short shell end and the bottom end. At present, a single-sided single-layer TIG welding process is adopted for welding the butt joint annular seam between the box bottom and the short shell, the welding method has great dependence on operators, the operators need to adjust welding parameters such as welding current, wire feeding speed, welding speed, arc voltage and the like at any time according to the state of a molten pool, and the requirements of judging the critical point of a penetration molten pool on the experience level and professional skills of the operators are high due to the special transition annular structure. Welding defects such as incomplete penetration and burn-through are easy to generate, and when the X-ray negative film is interpreted, welding defect detection conclusions interpreted by different personnel are different, so that the method brings serious challenges to later product repair and product quality.

With the shortage of national strategic situation, the requirements of high stability and high reliability of the welded joint of the type carrier rocket are continuously improved, the problem of welding defects cannot be fundamentally solved by adopting the traditional fusion welding process method, and through years of technical attack, the engineering application of the friction stir welding technology on the spherical crown box bottom and the short shell is gradually developed and realized in China.

The prior welding process method for butt joint and girth between the box bottom and the short shell mainly has the following defects:

(1) The traditional TIG welding process method needs operators to adjust welding process parameters at any time according to the state of a molten pool, has large dependency on operators, cannot guarantee the welding quality of products, and is not suitable for manufacturing mass products.

(2) The weld defects are not fundamentally eliminated, and present significant pressure and challenges to the interpretation of X-ray films.

Disclosure of Invention

In view of the above, the invention aims to provide a vertical assembly method for butt joint annular seams of spherical crown bottoms and short shells, so as to solve the problem of unavoidable welding defects generated by the traditional fusion welding method for the spherical crown bottoms and short shell butt joint annular seams with the diameter of 5000 mm.

In order to achieve the above purpose, the technical scheme of the invention is realized as follows:

a spherical crown box bottom and short shell butt joint circular seam vertical assembly method comprises the following steps:

s1, hoisting a box bottom assembly to a circular seam membrane tire;

s2, installing a fork ring pressing mechanism, pressing a fork ring welding end, and presetting the roundness of the fork ring welding end after being supported out through 8 points;

s3, hoisting the welding plate assembly to the interior of the fork-shaped ring groove;

s4, hoisting the short shell to the circular seam membrane tire;

s5, hoisting a short shell compaction tool;

s6, adjusting the internal and external supporting quantity of the welding backing plate and the roundness of the welding seam;

s7, adopting fixed-position welding and formal back-pumping friction stir welding;

s8, after welding is completed, removing the compaction tool;

s9, dismantling a welding backing plate;

s10, taking out flash on the surface of the welding seam and polishing the welding seam;

s11, detecting the welding seam phased array.

Further, in step S3, the welding plate assembly includes a support plate, a welding backing plate, an expansion plate and a floating joint, the support plate is welded to the inside of a fork ring groove of the fork ring pressing mechanism, a welding groove is formed in one side of the top of the support plate, the welding backing plate is arranged on one side of the inner wall of the welding groove, the expansion plate is arranged on the other side of the inner wall of the welding groove, and the top of the expansion plate is fixedly connected to the floating joint.

Further, the supporting plate is matched with the inner groove profile of the fork-shaped ring pressing mechanism.

Furthermore, the front views of the welding backing plate and the expansion plate are all trapezoid structures.

Further, the step S3 of lifting the welding plate assembly to the inside of the fork-shaped ring groove comprises the following steps:

s31, the supporting plates are contacted with two ends of the inner groove of the fork ring;

s32, tightening the bolts to drive the expansion plate to move downwards;

and S33, the welding backing plate moves outwards, the backing plate and the back of the product are attached, and the gap between the backing plate and the product is controlled.

Further, the range of the puncture gap in step S33 is 0.3mm or less.

Further, the step S4 of hoisting the short shell to the circular seam membrane tire comprises the following steps:

s41, enabling the short shell to move downwards along the welding backing plate;

s42, tightly pushing the end part of the short shell by one end of 8 pressing rods;

s43, pressing the upper end face of the welding backing plate by using 8 other pressing rods.

Further, the weld roundness range in step S6 is 0.5mm or less.

Compared with the prior art, the spherical crown box bottom and short shell butt joint annular seam vertical assembly method has the following advantages:

(1) The invention provides a spherical crown tank bottom and short shell butt joint circumferential seam vertical assembly method, provides a 5m diameter tank bottom and short shell butt joint circumferential seam vertical assembly friction stir welding concept, develops a vertical assembly process method for a 5m diameter storage tank bottom and short shell, and realizes the assembly friction stir welding of a 5m large diameter tank bottom and short shell in a vertical state for the first time.

(2) The invention discloses a vertical assembly method for a butt joint circular seam of a spherical crown box bottom and a short shell, which develops an assembly method for the upper surface of a symmetrical 8-point type pre-tightening, stress-applying tightening round adjustment and auxiliary compression bar compression backing plate, solves the problems that the butt joint circular seam of the box bottom and the short shell and a welding backing plate do not stick to a tire, the roundness change of a product is rapid, and the backing plate moves to the upper side of the short shell under the action of tightening force, the assembly roundness is controlled within 0.5mm, and the tire sticking gap is controlled within 0.3mm.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 is a schematic diagram of a transition ring of a method for vertically assembling a spherical crown box bottom and a short shell butt joint circumferential seam according to an embodiment of the invention;

FIG. 2 is a process flow diagram of a butt-joint girth process for assembling a spherical crown case bottom and short shell butt-joint girth vertically according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an assembled box bottom assembly according to the embodiment of the invention by a spherical crown box bottom and short shell butt joint circular seam vertical assembly method;

FIG. 4 is a schematic view of a welding plate assembly of a spherical crown box bottom and short shell butt joint circumferential seam vertical assembly method according to an embodiment of the invention;

FIG. 5 is an enlarged view of a welded plate assembly according to the embodiment of the invention, which is a vertical assembly method for butt joint and circumferential seam between a spherical crown box bottom and a short shell;

FIG. 6 is a schematic diagram illustrating a module pulling and pressing process for adjusting a welding backing plate according to a method for vertically assembling a spherical crown box bottom and a short shell butt joint circumferential seam according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating a process of adjusting a pull-out screw of a welding backing plate by a spherical crown box bottom and short shell butt joint circumferential seam vertical assembly method according to an embodiment of the invention;

FIG. 8 is a schematic diagram of a method for assembling a short shell by a spherical crown box bottom and short shell butt joint circumferential seam vertical assembly method according to an embodiment of the invention;

FIG. 9 is a schematic diagram of an installation compaction tool for a spherical crown box bottom and short shell butt joint circumferential seam vertical assembly method according to an embodiment of the invention;

fig. 10 is a schematic diagram of a hanging tool for a spherical crown box bottom and short shell butt joint circumferential seam vertical assembly method according to an embodiment of the invention.

Reference numerals illustrate:

1. a bottom assembly; 2. circular seam membrane tyre; 3. a fork-shaped ring pressing mechanism; 4. welding the plate assembly; 41. a support plate; 42. welding a backing plate; 43. an expansion plate; 44. a floating joint; 5. short shells.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.

The invention will be described in detail below with reference to the drawings in connection with embodiments.

As shown in fig. 1 to 10, a method for vertically assembling a spherical crown box bottom and a short shell butt joint circumferential seam comprises the following steps:

s1, hoisting a box bottom assembly 1 to a circular seam membrane tire 2;

s2, installing a fork ring pressing mechanism 3, pressing the welding end of the fork ring, and presetting the roundness of the welding end of the fork ring after being supported by 8 points;

s3, hoisting the welded plate assembly 4 to the inside of the fork-shaped ring groove;

s4, hoisting the short shell 5 to the circular seam membrane tire 2;

s5, hoisting a short shell compaction tool;

s6, adjusting the internal and external supporting quantity and the weld roundness of the welding backing plate 42;

s7, welding, namely adopting fixed-position welding and formal back-suction friction stir welding;

s8, after welding is completed, removing the compaction tool;

s9, dismantling a welding backing plate;

s10, taking out flash on the surface of the welding seam and polishing the welding seam;

s11, detecting the welding seam phased array. The invention aims to solve the unavoidable welding defect problem generated by the traditional fusion welding method of the spherical crown box bottom with the spherical crown box short in diameter, and adopts the vertical assembly welding method of the box bottom and the spherical crown box short in diameter, namely, the box bottom assembly is assembled at the annular seam station of the box bottom first, the spherical crown box bottom is assembled with the spherical crown short in diameter, the main shaft is rotationally fixed during welding, the butt annular seam welding work is completed through the rotating film tire, the problems that the back of the transition annular seam of the spherical crown box bottom is suspended, the internal measuring space is narrow and the structural design of a welding seam supporting backing plate is limited are solved, and the popularization and the application of the stirring friction welding technology in the spherical crown box bottom with the spherical crown short in diameter and the spherical crown box short in diameter are realized. The invention provides a 5m diameter tank bottom and short shell butt joint annular seam vertical assembly friction stir welding concept, and develops a vertical assembly process method for the 5m diameter tank bottom and short shell, so that the assembly friction stir welding of the 5m large diameter tank bottom and the short shell in a vertical state is realized for the first time.

The welding plate assembly 4 in step S3 comprises a support plate 41, a welding backing plate 42, an expansion plate 43 and a floating joint 44, the support plate 41 being welded to the inside of the fork-shaped ring groove of the fork-shaped ring press mechanism 3, said support plate 41 matching the profile of the fork-shaped ring inner groove of the fork-shaped ring press mechanism 3. A welding groove is formed in one side of the top of the supporting plate 41, a welding backing plate 42 is arranged on one side of the inner wall of the welding groove, an expansion plate 43 is arranged on the other side of the inner wall of the welding groove, and the top of the expansion plate 43 is fixedly connected to a floating joint 44. The front view of the welding backing plate 42 and the expansion plate 43 are both trapezoid structures. The advantage is so that the whole block type hoisting method is adopted, and the operation is simple, economical and practical.

The step S3 of lifting the welding plate assembly 4 to the interior of the fork-shaped ring groove comprises the following steps:

s31, the supporting plate 41 is contacted with two ends of the inner groove of the fork ring;

s32, screwing the bolt to drive the expansion plate 43 to move downwards;

and S33, the welding backing plate 42 moves outwards, the back of the product is pasted with the tyre, and the tyre pasting gap is controlled. The traditional 5m box bottom and short shell butt joint circular seam are assembled and welded on a 5m frame, so that the welding efficiency is low, and the welding quality cannot be effectively ensured. The outer side of the transition ring at the bottom of the spherical crown box extends out, the back of the welding line is suspended, the internal measurement space is narrow, the structural design of the welding line support backing plate is limited, and great difficulty is brought to the research of friction stir welding technology. The research of the friction stir welding process of the butt joint annular seam of the spherical crown box bottom and the short shell is carried out, and the vertical assembly welding concept of the box bottom and the short shell is provided, namely, the box bottom assembly is assembled at the box bottom annular seam station first, the short shell is assembled again, and when in welding, the main shaft is rotationally fixed, the butt joint annular seam welding work is completed through the rotating film tire, the problems of dependence on operators in the welding process of the butt joint annular seam of the box bottom and the short shell, potential quality hazards easily occurring in the welding process and the like are solved, the requirements of the butt joint welding seam of the box bottom and the short shell on high process reliability, stability and small deformation are met, and the purpose that the friction stir welding technology is popularized and applied in the butt joint annular seam of the spherical crown box bottom with the short shell in the phi 5000mm level is achieved.

The range of the tire sticking gap in step S33 is less than or equal to 0.3mm. The roundness range of the weld in step S6 is less than or equal to 0.5mm. In the embodiment, the invention develops an assembly method of ' symmetrical 8-point type ' pre-tightening, boosting tightening and circle adjusting ' and auxiliary pressing rod for pressing the upper surface of the backing plate, solves the problems that a butt joint circular seam between the box bottom and the short shell and a welding backing plate do not stick to a tire, the roundness change of a product is rapid, and the backing plate moves above the short shell under the action of tightening force, the assembly roundness is controlled within 0.5mm, and the tire sticking gap is controlled within 0.3mm.

The process of hoisting the short shell 5 to the circular seam membrane tyre 2 in the step S4 comprises the following steps:

s41, moving the short shell 5 downwards along the welding backing plate 42;

s42, tightly pushing the end part of the short shell 5 by one end of 8 pressing rods;

s43, pressing the upper end face of the welding backing plate 42 by using 8 other pressing rods. Thereby further adjusting the roundness of the welding seam, and adopting a positioning welding and formal back-drawable friction stir welding process to weld the circumferential seam after the process requirement is met.

Example 1

In this embodiment, the specific technical scheme is as follows:

1. hoisting the box bottom assembly 1 to the circular seam membrane tire 2, leveling the box bottom assembly 1 through a bottom leveling device according to the theoretical height, installing a fork-shaped ring pressing mechanism 3, pressing the welding ends of the fork-shaped rings, and particularly as shown in fig. 3, simultaneously pressing two sides of a welding seam by a fork-shaped ring pressing tool and a short shell pressing tool 5, pressing the upper surface of the short shell by a pressing rod, and limiting the upward movement of the short shell during welding.

2. 4 welded plate assemblies 4 are hoisted in sequence to the inside of the fork-shaped ring groove, the backing plate mainly comprises 3 parts, as shown in fig. 4-5, a wedge block, a welded backing plate and a chock expansion plate are respectively arranged, the three parts are fixed together through bolts, and an integral block type hoisting method is adopted, and the principle is as follows: the white wedge block part is consistent with the molded surface of the groove inside the fork-shaped ring, as shown in fig. 6-7, the white wedge block part contacts with the two ends of the groove inside the fork-shaped ring after being assembled, the yellow plug block part moves downwards, the welding backing plate of the red part is pushed to move outwards under the action of external force and the wedge surface, and the welding backing plate 42 and the back of a product achieve the purpose of sticking the tire under the action of the outward supporting force of the welding backing plate 42. After the box bottom assembly is assembled, the roundness of the welding end of the fork-shaped ring is preset through 8 points, the product is contacted with the backing plate after the bearing force is applied, and the subsequent work is performed after the roundness meets the technological requirement.

3. And the short shell is hoisted to the circular seam membrane tire 2, as shown in fig. 8, the short shell is enabled to move downwards along the welding backing plate 42, the short shell is hoisted to compress tightly the tool, the end position of the short shell is tightly propped against one end of 8 compressing rods through the compressing device shown in fig. 9, the upper end face position of the welding backing plate 42 is compressed tightly by the other 8 compressing rods, and when welding is prevented, the backing plate moves along the axial direction under the action of external pressure, so that the welding process is ensured to be stable. And meanwhile, according to the final assembly state, the internal and external supporting quantity of the welding backing plate 42 is adjusted through bolts, so that the roundness of the welding seam is further adjusted, and the welding is performed after the process requirement is met.

4. After the box bottom assembly 1 and the short shell are in butt joint and girth welding, the pressing tool is disassembled, the welding backing plate 42 is lifted out through a cross lifting tool, as shown in fig. 10, burrs on the surface of the welding seam are removed, the welding seam is polished, and phased array detection is performed on the welding seam.

Compared with other box bottom circumferential seams (4-7.2 mm), the thickness of the butt joint circumferential seams of the box bottom assembly 1 and the short shell depends on the thickness of the short shell, and the currently known condition is that the short shell has the thickness range of (10-25 mm) and belongs to large-thickness material welding, so that the aluminum alloy plate material back-drawing stirring head suitable for 10-25 mm is designed according to the current stirring head design principle, the diameter of a shaft shoulder is designed according to the range of 24-35 mm, and the root of the stirring pin is designed according to the range of 8-15 mm.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims (3)

1. A spherical crown box bottom and short shell butt joint circular seam vertical assembly method is characterized in that: the method comprises the following steps:

s1, hoisting a box bottom assembly (1) to a circular seam membrane tire (2);

s2, installing a fork ring pressing mechanism (3), pressing the welding end of the fork ring, and presetting the roundness of the welding end of the fork ring after being supported by 8 points;

s3, hoisting the welding plate assembly (4) to the inside of the fork-shaped ring groove;

s4, hoisting the short shell (5) to the circular seam membrane tire (2);

s5, hoisting the short shell (5) to compress the tool;

s6, adjusting the internal and external supporting quantity and the roundness of the welding seam of the welding backing plate (42);

s7, adopting fixed-position welding and formal back-pumping friction stir welding;

s8, after welding is completed, removing the compaction tool;

s9, dismantling a welding backing plate (42);

s10, taking out flash on the surface of the welding seam and polishing the welding seam;

s11, detecting a welding seam phased array;

the inner diameter of the bottom assembly (1) in step S1 is 5m;

the welding plate assembly (4) in the step S3 comprises a supporting plate (41), a welding backing plate (42), a swelling plate (43) and a floating joint (44), wherein the supporting plate (41) is welded into a fork-shaped ring groove of the fork-shaped ring pressing mechanism (3), one side of the top of the supporting plate (41) is provided with a welding groove, one side of the inner wall of the welding groove is provided with the welding backing plate (42), the other side of the inner wall of the welding groove is provided with the swelling plate (43), and the top of the swelling plate (43) is fixedly connected to the floating joint (44);

the step S3 of lifting the welding plate assembly (4) to the inside of the fork-shaped ring groove comprises the following steps of:

s31, the supporting plates (41) are contacted with two ends of the inner groove of the fork-shaped ring;

s32, tightening the bolt to drive the expansion plate (43) to move downwards;

s33, the welding backing plate (42) moves outwards, the backing plate and the back of the product are attached, and a gap between the backing plate and the product is controlled;

the range of the tire pasting gap in the step S33 is less than or equal to 0.3mm;

the step S4 of hoisting the short shell (5) to the circular seam membrane tire (2) comprises the following steps:

s41, enabling the short shell (5) to move downwards along the welding backing plate (42);

s42, tightly pushing the end part of the short shell (5) by one end of 8 pressing rods;

s43, pressing the upper end surface of the welding backing plate (42) by using 8 other pressing rods;

the roundness range of the weld in step S6 is less than or equal to 0.5mm.

2. The method for vertically assembling the spherical crown box bottom and the short shell butt joint annular seam according to claim 1, which is characterized in that: the supporting plate (41) is matched with the inner groove profile of the fork-shaped ring pressing mechanism (3).

3. The method for vertically assembling the spherical crown box bottom and the short shell butt joint annular seam according to claim 1, which is characterized in that: the front views of the welding backing plate (42) and the expansion plate (43) are of trapezoid structures.

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