Suspended negative pressure laser welding cabin and laser welding method
Through the design of suspended negative pressure laser welding chamber, the laval tube or shrink tube configuration shell and airflow control technology are used to solve the volume limitation and mobile wear problems of large workpiece welding, achieving high-precision and stable welding effect.
Patent Information
- Application Number
- CN202510739591.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2025-08-05
AI Technical Summary
The existing negative pressure welding equipment is limited by the volume of the sealed compartment, so it cannot weld large workpieces, and it is prone to wear during movement, which affects welding accuracy and stability and increases production costs.
The suspended negative pressure laser welding chamber is adopted, and the outer shell is designed through the Laval tube or shrink tube configuration, combined with the light-transmitting parts and the air extraction port to form a stable negative pressure environment, and the welding area is protected by a high-speed airflow barrier and air curtain to avoid external air invasion.
Welding of large workpieces is realized, avoiding moving wear, improving welding accuracy and stability, and reducing welding power requirements.
Smart Images
Figure CN120421789A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of negative pressure laser welding, and in particular relates to a suspended negative pressure laser welding cabin and a laser welding method. Background Art
[0002] With the development of modern welding technology, the importance of negative pressure laser welding has become increasingly significant. For specific welding tasks, such as welding reactive metals, a negative pressure environment can effectively remove harmful gases during the welding process and reduce the influx of impurities, thereby significantly improving the quality and stability of welded joints and meeting the stringent requirements of high-end manufacturing for product precision and reliability. Furthermore, when welding refractory metals, a negative pressure environment can reduce laser plasma eruption and increase the material's absorption rate of the laser, significantly reducing the power required for welding.
[0003] Traditional negative pressure equipment is a sealed cabin structure. Although it has achieved a negative pressure welding environment to a certain extent, it has drawbacks that are difficult to overcome. Due to the limitation of the cabin volume, the size of the weldable workpiece is limited. It is often not usable when facing large welds such as large mechanical parts and aerospace structures, which seriously hinders the promotion and application of negative pressure laser welding technology in key areas. At the same time, existing local negative pressure equipment also has obvious defects. Most of them rely on the close fit between the bottom and the weldment to maintain negative pressure. During the welding process, once the equipment needs to be moved, it will cause serious wear problems, which not only reduces the service life of the equipment, but may also affect the accuracy and stability of the welding, and increase production costs and time costs. Therefore, the existing local negative pressure equipment is only suitable for spot welding needs because spot welding does not require movement. Summary of the Invention
[0004] In view of the above deficiencies in the prior art, the object of the present invention is to provide a suspended negative pressure laser welding chamber and a laser welding method.
[0005] In order to achieve the above objectives, the technical solutions adopted are: One of the purposes of the present invention is to provide a suspended negative pressure laser welding cabin, comprising a cabin body, a light-transmitting component provided at the top of the cabin body, a light-transmitting port provided at the bottom of the cabin body, an air exhaust port provided at the cabin body, an outer shell provided at the periphery of the cabin body, the outer shell being a Laval tube configuration or a shrinkage tube configuration (shrinking from top to bottom), an air inlet provided at the upper part of the outer shell, the air inlet being connected to a protective gas source, the bottom end of the outer shell being open, and an air outlet being formed between the bottom end of the outer shell and the cabin body inside, a flow-blocking groove provided at the bottom end of the cabin body, the flow-blocking groove being located at the periphery of the light-transmitting port.
[0006] The beneficial effects of adopting the above technical solution are as follows: the cabin adopts a suspended semi-enclosed design, which breaks away from the volume limitations of traditional sealed cabins, can adapt to large workpiece welding, avoids wear and tear during movement, and extends the life of the equipment; the provision of a light-transmitting component and a light-transmitting port enables laser penetration. At the same time, the light-transmitting component ensures the sealing of the cabin top, and the provision of an exhaust port creates a negative pressure environment inside the cabin. The negative pressure environment reduces laser scattering and plasma shielding effects, effectively removes harmful gases and impurities during welding, and reduces the welding power required; the Laval tube configuration uses a convergent-divergent structure. After the shielding gas enters through the air inlet, it is accelerated to sonic speed at the throat and further accelerated to supersonic speed in the divergent section, forming a high-stiffness and high-stability airflow barrier. The wall effect of the supersonic airflow effectively prevents external air from intruding into the welding area below the cabin. The contracting tube configuration is suitable for subsonic airflow scenarios, forming a dynamic air curtain through high-speed airflow to maintain a negative pressure environment. Both configurations effectively prevent external air from intruding into the welding area, providing dual protection of negative pressure and air curtain, improving weld quality.
[0007] Preferably, a plurality of flow-blocking rings are provided at the bottom end of the cabin body, and the plurality of flow-blocking rings are arranged at intervals and in a concentric ring structure, and the flow-blocking grooves are formed between adjacent flow-blocking rings.
[0008] Preferably, the blocking ring (blocking groove) is arranged vertically or inclined, and the inclined arrangement is such that the blocking ring (blocking groove) is inclined from the upper end to the lower end in a direction away from the light-transmitting port, that is, the blocking ring (blocking groove) is trumpet-shaped, or the blocking ring (blocking groove) is inclined from the upper end to the lower end in a direction close to the light-transmitting port, more preferably in a trumpet-shaped shape.
[0009] Preferably, when tilted, the angle between the choke groove and the vertical direction is 40°-50°, the interval between adjacent choke rings, i.e. the width of the choke groove, is 1mm-2mm, the depth of the choke groove is 7mm-9mm, and the number of the choke grooves is 5-10.
[0010] The beneficial effects of adopting this preferred technical solution are as follows: The concentric annular flow-blocking grooves gradually reduce air pressure through a multi-stage expansion-decompression process (labyrinth sealing principle), ensuring stable air pressure in the welding area. The trumpet-shaped inclination (40°-50°) guides the airflow outward, reducing direct impact on the welding area while enhancing the coverage of the air curtain. The 1-2mm gap creates a narrow airflow channel while avoiding contact wear, balancing the internal and external pressure differences. The 7-9mm depth ensures ample space for airflow expansion.
[0011] Preferably, the light-transmitting component includes light-transmitting glass, a first mounting groove is provided at the top of the cabin body, the light-transmitting glass is located in the first mounting groove, and a top cover for pressing the light-transmitting glass is provided at the upper end of the light-transmitting glass, and the top cover is annular.
[0012] The beneficial effects of adopting the above-mentioned preferred technical solution are: the cooperation between the light-transmitting glass and the first mounting groove ensures the top sealing, the annular top cover provides uniform pressing force to avoid stress concentration, and the overall efficient transmission of the laser and the sealing of the cabin are guaranteed.
[0013] Preferably, a bottom cover is provided at the bottom end of the cabin body, the bottom cover is annular, the light transmission port is located in the middle of the bottom end of the cabin body, the bottom cover is located circumferentially of the light transmission port, and the upper end of the flow blocking ring is connected to the lower end of the bottom cover.
[0014] The beneficial effects of adopting the above-mentioned preferred technical solution are: the annular bottom cover is threadedly connected to the cabin body, which is convenient for disassembly and maintenance; the integrated design with the baffle ring forms a complete airflow control system; and the central light-transmitting port ensures that the laser path is unobstructed.
[0015] Preferably, a shell throat is provided between the top and bottom of the shell, an inner diameter reduction section is included from the top of the shell to the shell throat, and an inner diameter expansion section is included from the shell throat to the bottom of the shell, that is, a Laval tube configuration.
[0016] The beneficial effect of adopting the above-mentioned preferred technical solution is that the throat structure realizes the key transition of airflow acceleration.
[0017] Preferably, the edge of the bottom end of the shell is rounded.
[0018] The beneficial effects of adopting the above-mentioned preferred technical solution are: optimizing airflow guidance, reducing turbulence, and enhancing the sealing of the air curtain.
[0019] Preferably, the air inlet is connected to an air compressor, and the air inlet is provided in plurality and arranged along the circumference of the cabin body, more preferably evenly arranged along the circumference of the cabin body.
[0020] The beneficial effects of adopting the above-mentioned preferred technical solution are: connecting the air compressor to provide a stable compressed high-flow rate protective air source, and multiple circumferential air inlets to ensure uniform air flow distribution and improve air intake efficiency.
[0021] Preferably, the cabin body is a uniform cylinder with the same inner diameter at the top and bottom.
[0022] Preferably, the cabin is provided with a pressure measuring device connection port, and the pressure measuring device connection port is connected to a pressure measuring device, and the pressure measuring device is preferably a pressure gauge.
[0023] The beneficial effects of adopting the above preferred technical solution are: the pressure measuring device monitors the cabin pressure in real time, Ensure the stability of the negative pressure environment and provide data support for process adjustments.
[0024] More preferably, the air extraction port is connected to a vacuum extraction device.
[0025] The beneficial effects of adopting the above-mentioned preferred technical solution are: quickly establishing the required negative pressure environment, maintaining stable pressure in the welding area, and working in coordination with the airflow system.
[0026] Preferably, a laser emitting device is provided above the top cover.
[0027] Preferably, a second mounting groove is provided at the connection between the cabin and the outer shell, and the inner side of the top end of the outer shell is located in the second mounting groove.
[0028] The beneficial effect of adopting the above-mentioned preferred technical solution is that the second mounting groove realizes the precise positioning of the housing, ensures the dimensional accuracy of the air flow channel, and improves the equipment assembly efficiency.
[0029] Preferably, the bottom cover is connected to the cabin body through threads.
[0030] The beneficial effect of adopting the above preferred technical solution is that the bottom cover is easy to disassemble and maintain.
[0031] Preferably, the housing comprises a left half shell and a right half shell, which facilitates installation and disassembly.
[0032] A second object of the present invention is to provide a suspended negative pressure laser welding method, using the suspended negative pressure laser welding chamber, comprising the following steps: Step 1: Before welding, place the suspended negative pressure laser welding chamber above the plate to be welded, so that the distance between the lower end of the baffle ring and the plate to be welded is 1-2 mm; Step 2: High-flow shielding gas is injected into the shell through the air inlet at the top of the shell. The shielding gas is accelerated in the shell, and the airflow velocity exceeds the speed of sound. It has a wall effect and a large stiffness, and is ejected outwards through the air outlet at the bottom of the shell along the inner wall of the shell, preventing outside air from flowing into the cabin. Step 3: Extract the air from the air outlet of the cabin to ensure that the pressure near the welding area below the light-transmitting port is reduced; Step 4: Turn on the laser emitting device above the suspended negative pressure laser welding chamber. The laser passes through the transparent glass and the light-transmitting port in turn to act on the surface of the plate to be welded, and welding begins.
[0033] Preferably, the suspended negative pressure laser welding method, in step three, after the gas in the cabin is extracted from the exhaust port of the cabin, also includes the following steps: the protective gas flow in the outer shell close to the cabin side passes through the gap between the bottom cover and the plate to be welded, and a small amount of it flows toward the welding area below the light-transmitting port under the drive of the pressure difference, while the fluid stiffness generated by the high-speed flow of the remaining air flow will not change the flow path. The part of the high-speed air flow flowing to the welding area will expand and reduce pressure each time it passes through the flow groove between a flow ring and the flow ring, until it reaches the welding area and reaches the same air pressure value as the welding area, thereby ensuring the stability of the air pressure in the welding area.
[0034] Compared with existing technologies, the present invention offers significant advantages: It discloses a suspended negative pressure laser welding chamber. Through a rational aerodynamic structural design and airflow control technology, this chamber accurately creates a stable negative pressure zone around the weld site without relying on bottom contact. In practice, this eliminates the limitations of chamber volume and avoids wear and tear from movement, potentially expanding the application of negative pressure laser welding technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 This is a schematic structural diagram of the suspended negative pressure laser welding cabin of the present invention; Figure 2 2. It is a cross-sectional view of the suspended negative pressure laser welding cabin of the present invention; Figure 3 This is a cross-sectional view of the cabin body of the suspended negative pressure laser welding cabin of the present invention; Figure 4 Schematic diagram of the half-shell structure of the outer shell of the suspended negative pressure laser welding cabin of the present invention; Figure 5 This is a structural schematic diagram of the bottom cover and flow blocking ring of the suspended negative pressure laser welding chamber of the present invention; Figure 6 This is a cross-sectional view showing the positional relationship between the suspended negative pressure laser welding chamber and the plate to be welded according to the present invention; The figures are marked as follows: 1. light-transmitting glass; 2. top cover; 3. cabin; 4. outer shell; 5. bottom cover; 6. exhaust port; 7. connection port of pressure measuring device; 9. throat of outer shell; 10. air outlet; 11. first mounting groove; 12. second mounting groove; 13. thread; 14. air inlet; 15. flow-blocking ring; 16. light-transmitting port; 17. plate to be welded; 18. flow-blocking groove; 19. fillet. DETAILED DESCRIPTION
[0036] The present invention is described below with reference to examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.
[0037] refer to Figures 1 to 6A suspended negative pressure laser welding cabin includes a cabin body 3, a light-transmitting component is provided at the top of the cabin body 3, a light-transmitting port 16 is provided at the bottom end of the cabin body 3, an air extraction port 6 is provided at the periphery of the cabin body 3, and an outer shell 4 is provided. The outer shell 4 is a Laval tube configuration or a shrink tube configuration (shrinking from top to bottom), an air inlet 14 is provided at the upper part of the outer shell 4, and the air inlet 14 is connected to a protective gas source. The bottom end of the outer shell 4 is open, and an air outlet 10 is formed between the bottom end of the outer shell 4 and the internal cabin body 3. A flow blocking groove 18 is provided at the bottom end of the cabin body 3, and the flow blocking groove 18 is located at the periphery of the light-transmitting port 16.
[0038] As a preferred embodiment, a plurality of flow-blocking rings 15 are provided at the bottom end of the cabin body 3 . The plurality of flow-blocking rings 15 are arranged at intervals and in a concentric ring structure, and the flow-blocking grooves 18 are formed between adjacent flow-blocking rings 15 .
[0039] In some preferred embodiments, the blocking ring 15 (blocking groove 18) is vertically or tilted, and the tilted setting is that the blocking ring 15 (blocking groove 18) is tilted from the upper end to the lower end in a direction away from the light-transmitting port 16, that is, the blocking ring 15 (blocking groove 18) is trumpet-shaped (such as Figure 2 and Figure 5 As shown), or the blocking ring 15 (blocking groove 18) is inclined from the upper end to the lower end toward the direction close to the light-transmitting port 16, more preferably in a trumpet shape. When inclined, the angle between the blocking groove 18 and the vertical direction is 40°-50°, the interval between adjacent blocking rings 15, that is, the width of the blocking groove 18 is 1mm-2mm, the depth of the blocking groove 18 is 7mm-9mm, and the number of the blocking grooves 18 is 5-10.
[0040] As a preferred embodiment, the light-transmitting component includes a light-transmitting glass 1, and a first mounting groove 11 is provided at the top of the cabin body 3. The light-transmitting glass 1 is located in the first mounting groove 11. The upper end of the light-transmitting glass 1 is provided with a top cover 2 for pressing the light-transmitting glass 1. The top cover 2 is annular, and the top cover 2 is connected to the cabin body 3 by bolts.
[0041] As a preferred embodiment, the bottom end of the cabin body 3 is provided with a bottom cover 5, the bottom cover 5 is annular, the light-transmitting port 16 is located in the middle of the bottom end of the cabin body 3, the bottom cover 5 is located circumferentially of the light-transmitting port 16, and the upper end of the flow-blocking ring 15 is connected to the lower end of the bottom cover 5.
[0042] As a preferred embodiment, a shell throat 9 is provided between the top end of the shell 4 and the bottom end of the shell 4, and an inner diameter reduction section is included from the top end of the shell 4 to the shell throat 9, and an inner diameter expansion section is included from the shell throat 9 to the bottom end of the shell 4, which is a Laval tube configuration.
[0043] As a preferred embodiment, the edge of the bottom end of the housing 4 is a rounded corner 19 .
[0044] As a preferred embodiment, the air inlet 14 is connected to an air compressor, and the air inlet 14 is provided in plurality and arranged along the circumference of the cabin 3, more preferably evenly arranged along the circumference of the cabin 3. Figure 4 A situation is shown in which there are twelve air inlets 14 per half-shell.
[0045] As a preferred embodiment, the cabin body 3 is a uniform cylinder with the same inner diameter at the top and bottom.
[0046] As a preferred embodiment, the cabin 3 is provided with a pressure measuring device connection port 7, and the pressure measuring device connection port 7 is connected to a pressure measuring device, which is preferably a pressure gauge.
[0047] As a preferred embodiment, the air extraction port 6 is connected to a vacuum extraction device, which is a vacuum pump in this embodiment.
[0048] As a preferred embodiment, a laser emitting device, specifically a laser, is provided above the top cover 2 .
[0049] As a preferred embodiment, a second mounting groove 12 is provided at the connection between the cabin body 3 and the outer shell 4 , and the inner side of the top end of the outer shell 4 is located in the second mounting groove 12 .
[0050] In this embodiment, the bottom cover 5 is connected to the cabin body 3 via threads 13 .
[0051] In this embodiment, the housing 4 includes a left half shell and a right half shell, which is convenient for installation and disassembly.
[0052] The present invention also provides a suspended negative pressure laser welding method, using the suspended negative pressure laser welding chamber, comprising the following steps: Step 1: Before welding, place the suspended negative pressure laser welding chamber above the plate 17 to be welded, so that the distance between the lower end of the baffle ring 15 and the plate 17 to be welded is 1-2 mm; Step 2: Use an external air compressor to inject compressed high-flow shielding gas into the shell 4 through the air inlet 14 at the top of the shell 4. The shielding gas is accelerated in the shell 4, and the air flow velocity exceeds the speed of sound. It has a wall effect and a large stiffness. It is ejected outwards through the air outlet 10 at the bottom of the shell 4 along the inner wall of the shell 4, preventing outside air from flowing into the cabin 3. Step 3: Turn on the vacuum device and extract the gas in the cabin from the exhaust port 6 of the cabin body 3 to ensure that the pressure near the welding area below the light transmission port 16 is reduced. After the vacuum device is turned on, the protective gas flow near the cabin body 3 in the shell 4 passes through the gap between the bottom cover 5 and the plate 17 to be welded. Driven by the pressure difference, a small amount of it will flow to the welding area below the light transmission port 16, while the fluid stiffness generated by the high-speed flow of the remaining air flow will not change the flow path. The part of the high-speed air flow flowing to the welding area will expand and reduce pressure each time it passes through the gap (blocking groove 18) between a blocking ring 15 and the blocking ring 15, until it reaches the same air pressure value as the welding area when it reaches the welding area, thereby ensuring the stability of the air pressure in the welding area. Step 4: Turn on the laser emitting device above the suspended negative pressure laser welding chamber, and the laser passes through the transparent glass 1 and the light-transmitting port 16 in turn to act on the surface of the plate 17 to be welded, and welding begins.
[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A suspended negative pressure laser welding chamber, comprising a chamber body (3), characterized in that: The top of the cabin (3) is provided with a light-transmitting component, the bottom of the cabin (3) is provided with a light-transmitting port (16), the cabin (3) is provided with an air extraction port (6), the periphery of the cabin (3) is provided with an outer shell (4), the outer shell (4) is a Laval tube configuration or a shrink tube configuration, the upper part of the outer shell (4) is provided with an air inlet (14), the air inlet (14) is connected to a protective air source, the bottom end of the outer shell (4) is open, and an air outlet (10) is formed between the bottom end of the outer shell (4) and the cabin (3) inside, the bottom end of the cabin (3) is provided with a flow blocking groove (18), and the flow blocking groove (18) is located on the periphery of the light-transmitting port (16).
2. The suspended negative pressure laser welding chamber according to claim 1, characterized in that: A plurality of flow-blocking rings (15) are provided at the bottom end of the cabin body (3), and the plurality of flow-blocking rings (15) are arranged at intervals and in a concentric ring structure, with the flow-blocking grooves (18) formed between adjacent flow-blocking rings (15).
3. The suspended negative pressure laser welding chamber according to claim 2, characterized in that: The flow blocking groove (18) is inclined from the upper end to the lower end in a direction away from the light transmission opening (16).
4. The suspended negative pressure laser welding chamber according to claim 1, characterized in that: The light-transmitting component comprises a light-transmitting glass (1); a top cover (2) for pressing the light-transmitting glass (1) is provided at the upper end of the light-transmitting glass (1); the top cover (2) is annular.
5. The suspended negative pressure laser welding chamber according to claim 2, characterized in that: A bottom cover (5) is provided at the bottom end of the cabin body (3), the bottom cover (5) is annular, and the upper end of the flow blocking ring (15) is connected to the lower end of the bottom cover (5).
6. The suspended negative pressure laser welding chamber according to claim 1, characterized in that: A shell throat (9) is provided between the top end of the shell (4) and the bottom end of the shell (4); an inner diameter reduction section is included from the top end of the shell (4) to the shell throat (9); and an inner diameter expansion section is included from the shell throat (9) to the bottom end of the shell (4).
7. The suspended negative pressure laser welding chamber according to claim 1, characterized in that: The edge of the bottom end of the shell (4) is a rounded corner (19).
8. The suspended negative pressure laser welding chamber according to claim 3, characterized in that: The included angle between the flow blocking groove (18) and the vertical direction is 40°-50°, the interval between adjacent flow blocking rings (15) is 1mm-2mm, the depth of the flow blocking groove (18) is 7mm-9mm, and the number of the flow blocking grooves (18) is 5-10.
9. A suspended negative pressure laser welding method, characterized in that: Using the suspended negative pressure laser welding chamber according to any one of claims 1 to 8 comprises the following steps: Step 1: Before welding, the suspended negative pressure laser welding chamber is placed above the plate to be welded (17), so that the distance between the lower end of the flow blocking ring (15) and the plate to be welded (17) is 1 to 2 mm; Step 2: injecting high-flow-rate shielding gas into the housing (4) through the air inlet (14) at the upper portion of the housing (4); the shielding gas is accelerated in the housing (4); the air flow velocity exceeds the speed of sound; and the shielding gas is ejected outward along the inner wall of the housing (4) through the air outlet (10) at the bottom end of the housing (4), thereby preventing outside air from flowing into the cabin (3); Step 3: Extract the gas in the cabin from the exhaust port (6) of the cabin body (3) to ensure that the pressure near the welding area below the light-transmitting port (16) is reduced; Step 4: Turn on the laser emitting device above the suspended negative pressure laser welding chamber, and the laser acts on the surface of the plate to be welded (17) through the light-transmitting glass (1) and the light-transmitting port (16) in turn, and welding begins.
10. The suspended negative pressure laser welding method according to claim 9, characterized in that: In step three, after the gas in the cabin is extracted from the exhaust port (6) of the cabin body (3), the following steps are also included: the protective gas flow in the outer shell (4) close to the cabin body (3) passes through the gap between the bottom cover (5) and the plate to be welded (17), and a small amount of it flows toward the welding area below the light-transmitting port (16) under the drive of the pressure difference, while the fluid stiffness generated by the high-speed flow of the remaining air flow will not change the flow path. The part of the high-speed air flow flowing toward the welding area will expand and reduce pressure every time it passes through a flow groove (18) between a flow ring (15) and the flow ring (15), until it reaches the same air pressure value as the welding area when it reaches the welding area, thereby ensuring the stability of the air pressure in the welding area.