Heat exchanger shell and laser welding method thereof

Abstract

The present invention relates to a heat exchanger shell and a laser welding method thereof in the field of heat exchanger shell forming process technology. The shell is composed of a cylinder and a top cover and a bottom cover connected to both ends of the cylinder. The connection between the cylinder and the top cover and between the cylinder and the bottom cover is welded by two annular seam bottom locking butt joints, including the following steps: S1, locking groove processing step: S2, end cover installation step: S3, top cover and cylinder welding step: S4, bottom cover and cylinder welding step: S5, welding is completed. The present application adopts an embedded structure between the upper and lower end covers and the cylinder to form a bottom locking annular weld, which can effectively simplify the assembly process and ensure assembly accuracy. At the same time, it can avoid the generation of excess materials such as splashes inside the cylinder and eliminate quality risks.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchanger shell forming technology, and in particular to a heat exchanger shell and a laser welding method thereof. Background Art

[0002] For satellites, space shuttles, spacecraft and other aircraft, a critical issue that cannot be ignored is the thermal control problem inside the aircraft, that is, when the aircraft is in orbit, it is necessary to ensure that the single equipment inside and outside the cabin is always within the appropriate temperature range. For example, when an artificial satellite is orbiting the earth, it is sometimes exposed to the sun and sometimes in the shadow of the earth. This requires the thermal control device on the aircraft to play a cooling role when the temperature of the internal instruments of the satellite rises due to the sun's exposure to the artificial satellite, so as to avoid damage to the instruments due to excessive temperature; it also requires the thermal control device to play a temperature control role when the satellite is in the shadow of the earth and the internal temperature of the satellite drops, so as to provide a stable and appropriate thermal environment for the satellite's instruments.

[0003] With the continuous development of aerospace technology, new satellites with complex missions and diversified working modes have emerged, which has brought many technical difficulties to the thermal control design of satellites. Phase change materials can absorb and release a large amount of heat when melting and solidifying, and the temperature of the phase change material itself remains unchanged. This excellent property has led to phase change materials being widely used in thermal control devices of aircraft. Phase change heat exchanger is a large-capacity temperature regulating device that uses the principle of phase change heat absorption and heat release. The structural design of the heat exchanger shell implements lightweight and high-performance requirements. Therefore, its welding internal quality and external deformation have also become a major difficulty in product development. For example, the publication number CN110280902A discloses a laser welding process for the longitudinal seam of a 6-series aluminum alloy cylinder, which uses robots, brazing materials, lasers, etc. to avoid the occurrence of welding craters and cracks. It only focuses on the welding quality and does not pay attention to the adverse effects of welding on the internal surface during the welding process. Summary of the invention

[0004] In view of the defects in the prior art, an object of the present invention is to provide a heat exchanger shell and a laser welding method thereof.

[0005] A heat exchanger shell laser welding method provided by the present invention comprises the following steps:

[0006] S1, locking groove processing step: forming a top flange connecting plate and a bottom flange connecting plate at both ends of the cylinder respectively, processing an annular top locking groove on the top flange connecting plate, and processing an annular bottom locking groove on the bottom flange connecting plate;

[0007] S2, end cover installation step: connect the top cover to the top flange connecting plate by spot welding tooling, the edge of the top cover is clamped with the top locking groove, connect the bottom cover to the bottom flange connecting plate by welding tooling, the edge of the bottom cover is clamped with the bottom locking groove;

[0008] S3, top cover and cylinder welding step: clamp the welding fixture to the horizontal rotary positioner, and make the cylinder in an upright state, at which time the top cover is located at the upper end and the bottom cover is located at the lower end, firstly, the top cover and the top flange connecting plate are spot welded and fixed by laser welding, after which the spot welding fixture is disassembled, and then the top cover and the top flange connecting plate are circumferentially welded and bottom-locked by laser welding;

[0009] S4, bottom cover and cylinder welding step: remove the welding tool from the bottom flange connecting plate and install it on the top flange connecting plate, fasten the bottom cover and the bottom flange connecting plate by the spot welding tool, the edge of the bottom cover is clamped with the bottom locking groove, clamp the welding tool to the horizontal rotary positioner and make the cylinder stand upright, at this time the top cover is at the lower end and the bottom cover is at the upper end, firstly use laser welding to spot weld the bottom cover and the bottom flange connecting plate, remove the spot welding tool after spot welding, and then use laser welding to perform circumferential seam lock bottom welding on the bottom cover and the bottom flange connecting plate;

[0010] S5, welding is completed: the welding tool is removed from the top flange connecting plate, and the heat exchanger shell formed by welding the cylinder, the top cover and the bottom cover is placed in a predetermined position.

[0011] In some embodiments, the spot welding tool includes a fixing ring and a fixing support, a plurality of the fixing supports are spaced apart along the circumference of the fixing ring, and an end face of the fixing support includes a cover contact portion and a plate contact portion, the cover contact portion is used to contact the top cover or the bottom cover, and the plate contact portion is used to contact the top flange connecting plate or the bottom flange connecting plate.

[0012] In some embodiments, the fixing support is fastened to the top flange connection portion or the bottom flange connection plate by fastening screws.

[0013] In some implementations, in step S3 and step S4, the spot welding position for spot welding and fixing by laser welding is located between two adjacent fixed supports, and the length of the spot welding spot is 15-25 mm.

[0014] In some embodiments, the spot welding fixation adopts a two-dimensional oscillation laser wire filling welding process, and its process parameters are: laser power P = 4000W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocus amount δ = 0mm, oscillation frequency f = 500Hz, amplitude r = 0.55mm.

[0015] In some embodiments, in step S3 and step S4, the annular seam lock bottom welding adopts a two-dimensional oscillation laser wire filling welding process, and its process parameters are laser power P = 4500W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocus amount δ = 0mm, oscillation frequency f = 500Hz, and amplitude r = 0.55mm.

[0016] In some embodiments, the welding tool includes a cap shell and a boss, wherein the boss is connected to the middle part of the cap shell, the cap shell is used to accommodate the top cover and is fastened to the top flange connecting plate, or the cap shell is used to accommodate the bottom cover and is fastened to the bottom flange connecting plate, and the boss is used to accommodate a column located on the top cover or the bottom cover.

[0017] In some embodiments, the top locking groove is a stepped groove, and the edge of the top cover is provided with a clamping platform adapted to the top locking groove.

[0018] In some embodiments, the bottom locking groove is a stepped groove, and the edge of the bottom cover is provided with a clamping platform adapted to the bottom locking groove.

[0019] The present invention also provides a heat exchanger shell, which is formed by the heat exchanger shell laser welding method, and includes a cylinder, a top cover and a bottom cover;

[0020] The two ends of the cylinder are respectively formed with a top flange connecting plate and a bottom flange connecting plate, an annular top locking groove is processed on the top flange connecting plate, and an annular bottom locking groove is processed on the bottom flange connecting plate;

[0021] The edge of the top cover is buckled with the top locking groove and fixedly connected by laser welding, and the edge of the bottom cover is buckled with the bottom locking groove and fixedly connected by laser welding.

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

[0023] This embodiment adopts an embedded structure between the upper and lower end covers and the cylinder to form a bottom-locking ring weld, which can effectively simplify the assembly process, ensure assembly accuracy, and avoid the generation of excess materials such as splashes inside the cylinder, eliminating quality risks. In addition, the through-hole structure on the flange of the cylinder is utilized to design special welding tools and spot welding tools, effectively controlling the local warping deformation during the spot welding process, while improving the stability of the ring weld during the rotation welding process, ensuring the symmetry of the weld morphology and the consistency of the internal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0025] Figure 1 A schematic diagram of the structure of the heat exchanger shell for this application is provided with a spot welding fixture and a welding fixture;

[0026] Figure 2 for relative to Figure 1 Another side view of;

[0027] Figure 3 This is a schematic diagram of the structure of the cylinder of this application;

[0028] Figure 4 for relative to Figure 3 Another side view of;

[0029] Figure 5 This is a schematic diagram of the structure of the spot welding tooling for this application;

[0030] Figure 6 This is a schematic diagram of the structure of the welding tooling for this application;

[0031] Figure 7 This is a schematic diagram of the structure of the heat exchanger shell after welding is completed;

[0032] Figure 8 This is a schematic diagram of the structure of the top cover or bottom cover of this application. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a laser welding method for a heat exchanger shell, wherein the heat exchanger shell is a vertically symmetrical rotating body structure, such as Figure 1-8As shown, it is composed of a cylinder 1 and a top cover 2 and a bottom cover 3 connected to both ends of the cylinder 1. The connection between the cylinder 1 and the top cover 2 and the cylinder 1 and the bottom cover 3 is welded by two annular seam bottom lock butt joints, including the following steps:

[0036] S1, locking groove processing step: flange connection plates are formed at both ends of the cylinder 1, and the outer diameter of the flange connection plates is larger than the outer diameter of the cylinder body 1. The flange connection plates at both ends of the cylinder 1 are respectively recorded as the top flange connection plate 11 and the bottom flange connection plate 12. An annular top locking groove 101 is processed on the top flange connection plate 11. An annular bottom locking groove 102 is processed on the bottom flange connection plate 12.

[0037] In some embodiments, the top locking groove 101 is a stepped structure groove, and the edge of the top cover 2 that is connected to the top locking groove 101 is provided with a stepped clamping platform, and the stepped surfaces of the two are fitted and clamped. The stepped locking groove can further prevent damage to the inner wall of the cylinder during the welding process, and improve the welding forming quality of the heat exchanger shell. Correspondingly, the bottom locking groove 102 is also set as a stepped structure groove, and the edge of the bottom cover 3 is provided with a stepped clamping platform.

[0038] S2, end cover installation step: connect the top cover 2 to the top flange connecting plate 11 through the spot welding fixture 4, and after connection, the edge of the top cover 2 is stuck in the top locking groove 101. Connect the bottom cover 3 to the bottom flange connecting plate 12 through the welding fixture 5, and after connection, the edge of the bottom cover 3 is stuck in the bottom locking groove 102.

[0039] In some embodiments, the spot welding fixture 4 is a structure in which fixed blocks are arranged at intervals on a circular ring, and includes a fixed ring 41 and a fixed support 42. The fixed support 42 is a block-shaped body, and a plurality of fixed supports 42 are distributed at equal intervals along the circumference of the fixed ring 41. The end face of the fixed support 42 is divided into a cover body contact portion 421 and a plate body contact portion 422. The plate body contact portion 422 contacts the plate surface of the top flange connecting plate 11, and at the same time, the fixed support 42 is fastened to the top flange connecting plate 11 by the fastening screws 6. At this time, the cover body contact portion 421 contacts and presses the surface of the edge portion of the top cover 2.

[0040] The welding tool 5 is designed according to the contours of the top cover 2 and the bottom cover 3, and includes a cap shell 51 and a boss 52, wherein the boss 52 is connected to the middle of the cap shell 51. After the welding tool 5 is fastened to the bottom flange connecting plate 12 by the fastening screws 6, the bottom cover 3 is accommodated in the cap shell 51, and the edge of the bottom cover 3 is clamped in the bottom locking groove 102.

[0041] S3, welding steps of the top cover and the cylinder: clamp the welding tool 5 to the three-claw chuck of the horizontal rotary positioner, and make the cylinder 1 upright. At this time, the top cover 2 is located at the upper end and the bottom cover 3 is located at the lower end. First, laser welding is used to spot weld the top cover 2 and the top flange connecting plate 11. The spot welding position is located between two adjacent fixed supports 42, and the welding point length is 15-25mm. The laser welding used for spot welding is a two-dimensional oscillation laser wire filling welding process, and its process parameters are: laser power P = 4000W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocus δ = 0mm, oscillation frequency f = 500Hz, amplitude r = 0.55mm.

[0042] After the spot welding is fixed, the spot welding fixture 4 is disassembled, and then the top cover 2 and the top flange connecting plate 11 are welded to the bottom of the circumferential seam by laser welding. At this time, the laser welding process used in the bottom of the circumferential seam welding is still a two-dimensional oscillation laser wire welding process, and its process parameters are laser power P = 4500W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocusing amount δ = 0mm, oscillation frequency f = 500Hz, and amplitude r = 0.55mm.

[0043] S4, bottom cover and cylinder welding step: remove the welding jig 5 from the bottom flange connecting plate 12 and install it on the top flange connecting plate 11. The bottom cover 3 is fastened to the bottom flange connecting plate 12 by the spot welding jig 4. After the connection, the edge of the bottom cover 3 is clamped with the bottom locking groove 102. The plate body contact portion 422 contacts the plate surface of the bottom flange connecting plate 12, and at the same time, the fixed support 42 is fastened to the bottom flange connecting plate 11 by the fastening screws 6. At this time, the cover body contact portion 421 contacts and presses the surface of the edge portion of the bottom cover 3. The connection between the welding jig 5 and the top cover 2 is: the cap shell 51 is used to accommodate the top cover 2 and is fastened to the top flange connecting plate 11. The cap shell 51 is fastened to the top flange connecting plate 11 by the fastening screws 6.

[0044] Clamp the welding tool 5 onto the three-claw chuck of the horizontal rotary positioner, and make the cylinder 1 stand upright, with the top cover 2 at the lower end and the bottom cover 3 at the upper end. First, laser welding is used to spot weld the bottom cover 3 and the bottom flange connecting plate 12. The spot welding position is located between two adjacent fixed supports 42, and the welding spot length is 15-25mm. The laser welding used for spot welding is a two-dimensional oscillation laser wire welding process, and its process parameters are: laser power P = 4000W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocus δ = 0mm, oscillation frequency f = 500Hz, amplitude r = 0.55mm.

[0045] After the spot welding is fixed, the spot welding fixture 4 is disassembled, and then the bottom cover 3 and the bottom flange connecting plate 12 are welded to the bottom of the circumferential seam by laser welding. At this time, the laser welding process used in the circumferential seam welding is still a two-dimensional oscillation laser wire welding process, and its process parameters are laser power P = 4500W, welding speed v = 2m / min, wire feeding speed v = 2m / min, defocusing amount δ = 0mm, oscillation frequency f = 500Hz, and amplitude r = 0.55mm.

[0046] S5, welding is completed: the welding tool 5 is removed from the top flange connecting plate 11, and the heat exchanger shell formed by welding the cylinder 1, the top cover 2 and the bottom cover 3 is placed in a predetermined position.

[0047] This embodiment adopts an embedded structure between the upper and lower end covers and the cylinder to form a bottom-locking ring weld, which can effectively simplify the assembly process, ensure assembly accuracy, and avoid the generation of excess materials such as splashes inside the cylinder, eliminating quality risks. In addition, the through-hole structure on the flange of the cylinder is utilized to design special welding tools and spot welding tools, effectively controlling the local warping deformation during the spot welding process, while improving the stability of the ring weld during the rotation welding process, ensuring the symmetry of the weld morphology and the consistency of the internal quality.

[0048] Example 2

[0049] This embodiment 2 is formed on the basis of embodiment 1, and is a heat exchanger shell formed by the heat exchanger shell laser welding method of embodiment 1, including a cylinder 1, a top cover 2 and a bottom cover 3;

[0050] like Figure 1-8 As shown, the two ends of the cylinder 1 are respectively formed with a top flange connecting plate 11 and a bottom flange connecting plate 12, an annular top locking groove 101 is processed on the top flange connecting plate 11, and an annular bottom locking groove 102 is processed on the bottom flange connecting plate 12;

[0051] The edge of the top cover 2 is buckled with the top locking groove 101 and fixedly connected by laser welding, and the edge of the bottom cover 3 is buckled with the bottom locking groove 102 and fixedly connected by laser welding.

[0052] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0053] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A laser welding method for a heat exchanger shell, characterized in that: The steps include: S1, locking groove processing step: forming a top flange connecting plate (11) and a bottom flange connecting plate (12) at both ends of the cylinder (1), processing an annular top locking groove (101) on the top flange connecting plate (11), and processing an annular bottom locking groove (102) on the bottom flange connecting plate (12); S2, end cover installation step: connecting the top cover (2) to the top flange connecting plate (11) by means of a spot welding fixture (4), the edge of the top cover (2) being snap-fitted with the top locking groove (101), connecting the bottom cover (3) to the bottom flange connecting plate (12) by means of a welding fixture (5), the edge of the bottom cover (3) being snap-fitted with the bottom locking groove (102); S3, step of welding the top cover and the cylinder: the welding tool (5) is clamped onto the horizontal rotary positioner, and the cylinder (1) is placed in an upright state, at which time the top cover (2) is located at the upper end and the bottom cover (3) is located at the lower end. First, the top cover (2) and the top flange connecting plate (11) are spot welded and fixed by laser welding. After the spot welding, the spot welding tool (4) is disassembled, and then the top cover (2) and the top flange connecting plate (11) are circumferentially welded and bottom-locked by laser welding. S4, bottom cover and cylinder welding step: remove the welding jig (5) from the bottom flange connecting plate (12) and install it on the top flange connecting plate (11), fasten the bottom cover (3) and the bottom flange connecting plate (12) together by the spot welding jig (4), the edge of the bottom cover (3) is engaged with the bottom locking groove (102), clamp the welding jig (5) onto the horizontal rotary positioner and make the cylinder (1) stand upright, at which time the top cover (2) is located at the lower end and the bottom cover (3) is located at the upper end, firstly, laser welding is used to spot weld the bottom cover (3) and the bottom flange connecting plate (12) together, after spot welding, the spot welding jig (4) is removed, and then laser welding is used to perform circumferential seam lock bottom welding on the bottom cover (3) and the bottom flange connecting plate (12); S5, welding is completed: the welding tool (5) is removed from the top flange connecting plate (11), and the heat exchanger shell formed by welding the cylinder (1), the top cover (2) and the bottom cover (3) is placed in a predetermined work station.

2. The heat exchanger shell laser welding method according to claim 1, characterized in that: The spot welding fixture (4) comprises a fixing ring (41) and a fixing support (42), wherein a plurality of the fixing supports (42) are spaced apart along the circumference of the fixing ring (41), and an end surface of the fixing support (42) comprises a cover body contact portion (421) and a plate body contact portion (422), wherein the cover body contact portion (421) is used to contact the top cover (2) or the bottom cover (3), and the plate body contact portion (422) is used to contact the top end flange connecting plate (11) or the bottom end flange connecting plate (12).

3. The heat exchanger shell laser welding method according to claim 2, characterized in that: The fixed support (42) is fastened to the top flange connecting plate (11) or the bottom flange connecting plate (12) via fastening screws (6).

4. The heat exchanger shell laser welding method according to claim 2 or 3, characterized in that: In step S3 and step S4, the spot welding position for spot welding and fixing by laser welding is located between two adjacent fixed supports (42), and the length of the spot welding spot is 15-25 mm.

5. The heat exchanger shell laser welding method according to claim 4, characterized in that: The spot welding fixation adopts a two-dimensional oscillation laser wire-filling welding process, and its process parameters are: laser power P=4000W, welding speed v=2m / min, wire feeding speed v=2m / min, defocus amount δ=0mm, oscillation frequency f=500Hz, amplitude r=0.55mm.

6. The heat exchanger shell laser welding method according to claim 1, characterized in that: In step S3 and step S4, the annular seam lock bottom welding adopts a two-dimensional oscillation laser wire filling welding process, and its process parameters are laser power P=4500W, welding speed v=2m / min, wire feeding speed v=2m / min, defocus amount δ=0mm, oscillation frequency f=500Hz, and amplitude r=0.55mm.

7. The heat exchanger shell laser welding method according to claim 1, characterized in that: The welding tool (5) comprises a cap shell (51) and a boss (52), wherein the boss (52) is connected to the middle part of the cap shell (51), the cap shell (51) is used to accommodate the top cover (2) and is fastened to the top flange connecting plate (11), or the cap shell (51) is used to accommodate the bottom cover (3) and is fastened to the bottom flange connecting plate (12), and the boss (52) is used to accommodate a column located on the top cover (2) or the bottom cover (3).

8. The heat exchanger shell laser welding method according to any one of claims 1 to 7, characterized in that: The top locking groove (101) is a stepped groove, and the edge of the top cover (2) is provided with a clamping platform matched with the top locking groove (101).

9. The heat exchanger shell laser welding method according to claim 8, characterized in that: The bottom locking groove (102) is a stepped groove, and the edge of the bottom cover (3) is provided with a clamping platform matched with the bottom locking groove (102).

10. A heat exchanger housing, characterized in that: The heat exchanger shell is formed by the laser welding method according to any one of claims 1 to 9, comprising a cylinder (1), a top cover (2) and a bottom cover (3); The two ends of the cylinder (1) are respectively formed with a top flange connecting plate (11) and a bottom flange connecting plate (12); an annular top locking groove (101) is processed on the top flange connecting plate (11), and an annular bottom locking groove (102) is processed on the bottom flange connecting plate (12); The edge of the top cover (2) is buckled with the top locking groove (101) and fixedly connected by laser welding, and the edge of the bottom cover (3) is buckled with the bottom locking groove (102) and fixedly connected by laser welding.

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