Laser welded compressor housing and welding method thereof

Abstract

The present invention discloses a laser-welded compressor housing, comprising a lower housing (2) and an upper cover (1) matched therewith. The cross section of the upper cover (1) and the lower housing (2) at the connection is elliptical in shape. The upper cover (1) and the lower housing (2) are matched with a stopper. The maximum gap of the stopper is 0.5 mm. The present invention also discloses a laser welding method for the compressor housing. By adopting the above technical solution, continuous laser welding is achieved, with high welding efficiency and welding strength stronger than that of the parent material cold-rolled steel or hot-rolled steel. The welded joint has high strength and a neat and beautiful appearance. Fiber laser welding relies on the melting of the housing plate itself to form a molten pool connection, eliminating the need for welding wire and having a small thermal deformation area. Therefore, the damage of laser heat conduction to the pump body enclosed in the housing is greatly reduced, the product cost is reduced, and the product appearance quality and reliability are improved.

Description

Technical Field

[0001] The invention relates to a refrigeration compressor and a manufacturing technology thereof, and in particular to a welding structure of upper and lower shells of a compressor and a laser welding method. Background Art

[0002] Currently, shell welding is a bottleneck in the entire compressor production process, resulting in low welding efficiency and limited production capacity. Furthermore, the welding process consumes a large amount of consumables. For example, welding wire is required for each compressor weld. Welding leaks are common, leading to slag in the compressor, water ingress during water inspection, and even the complete unit being scrapped. Because welding wire is used during welding, slag often forms around the shell weld surface, severely affecting the compressor's appearance. Therefore, a brushing and slag removal process is required after girth welding, which is time-consuming, labor-intensive, and costly.

[0003] In the existing technology, due to the limitations of structural shape and process, laser welding has not yet been applied to the welding technology of compressor housings. Summary of the Invention

[0004] The laser-welded compressor housing and the corresponding welding method provided by the present invention aim to improve welding strength and production efficiency and to provide a more beautiful appearance.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] First option:

[0007] A laser-welded compressor housing comprises a lower housing and an upper cover matched therewith. The cross section where the upper cover and the lower housing are connected is elliptical in shape. The upper cover and the lower housing are matched with a stopper. The maximum clearance of the stopper is 0.5 mm.

[0008] The maximum melting depth of the molten pool formed by the weld between the upper cover and the lower shell is 1.8 mm, and the maximum melting height is 1.2 mm.

[0009] The height of the stop fitting is 8.5 to 9.5 mm.

[0010] The compressor casing welding method adopts a fiber optic welder with a laser power of 3.0 to 3.5 kW and a welding rate of 30 mm / s; the defocus amount is -1 to -1.2 mm; the weld shielding gas is argon or nitrogen with a flow rate of 20 to 30 L / min; the welding spot is focused and adjusted by optical fiber transmission, and its diameter is 0.6 to 1.0 mm.

[0011] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3.

[0012] More specifically, the gap between the upper cover and the lower shell forms a weld of 0.3 mm, the laser power of the optical fiber welder is 3.0 kW, the welding rate is 25 mm / s, the defocus amount is -1.0 mm, and the diameter of the welding spot is 0.6 mm to 0.7 mm.

[0013] Second option:

[0014] A laser-welded compressor housing comprises a lower housing and an upper cover mating therewith, wherein the cross-section at the connection between the upper cover and the lower housing is elliptical in shape; the upper cover and the lower housing are mated with a stopper; the maximum clearance of the stopper mating is 0.4 mm; the edge of the lower housing mating with the upper cover is provided with a lower housing stopper chamfer with a maximum depth not exceeding 1.2 mm and a width not exceeding 0.15 mm.

[0015] The maximum melting depth of the molten pool formed by the weld between the upper cover and the lower shell is 2.1 mm, and the maximum melting height is 1.5 mm.

[0016] The height of the stop fitting is 8.5 to 9.5 mm.

[0017] The welding method for the compressor housing uses a fiber optic welder with a laser power of 3.0kW and a welding rate of 30mm / s; the defocus amount is -1mm; the weld shielding gas is argon or nitrogen, and its flow rate is 25L / min; the welding spot is focused and adjusted through optical fiber transmission, and its diameter is 0.6~0.9mm.

[0018] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0019] The third option:

[0020] A laser-welded compressor housing comprises a lower housing and an upper cover mating therewith. The cross-section at the connection between the upper cover and the lower housing is elliptical in shape. The upper cover and the lower housing are mated with a stopper. The maximum clearance of the stopper is 0.4 mm. The edge of the lower housing mating with the upper cover is provided with a lower housing stopper R-arc with a maximum depth not exceeding 1.4 mm and a width not exceeding 0.15 mm.

[0021] The maximum melting depth of the molten pool formed by the weld between the upper cover and the lower shell is 2.3 mm, and the maximum melting height is 1.6 mm.

[0022] The height of the stop fitting is 8.5 to 9.5 mm.

[0023] The welding method for the compressor housing uses a fiber optic welder with a laser power of 3.0kW and a welding rate of 28mm / s; the defocus amount is -1.2mm; the weld shielding gas is argon or nitrogen, and its flow rate is 28L / min; the welding spot is focused and adjusted through optical fiber transmission, and its diameter is 0.6~1.0mm.

[0024] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0025] The fourth option:

[0026] A laser-welded compressor housing includes a lower housing and an upper cover that matches it. The upper cover and the lower housing are made of different materials. The cross-section where the upper cover and the lower housing are connected is elliptical. The upper cover and the lower housing are matched with a stopper. The maximum clearance of the stopper is 0.35 mm.

[0027] The material of the upper cover is aluminum alloy; the material of the lower shell is hot-rolled steel plate or cold-rolled steel plate.

[0028] The maximum melting depth of the molten pool formed by the weld between the upper cover and the lower shell is 2.5 mm, and the maximum melting height is 1.6 mm.

[0029] The height of the stop fitting is 8.5 to 9.5 mm.

[0030] The welding method for the compressor housing adopts a fiber optic welder with a laser power of 3.0 to 4.0 kW and a welding rate of 30 mm / s; the defocus amount is -1 to -1.5 mm; the weld shielding gas is argon or nitrogen, and its flow rate is 25 to 35 L / min; the welding spot is focused and adjusted by optical fiber transmission, and its diameter is 0.6 to 0.9 mm.

[0031] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0032] The laser spot is offset to the lower shell side by 0.05 to 0.15 mm.

[0033] The weld formed by the gap between the upper cover and the lower shell is 0.3mm, the laser power of the optical fiber welder is 3.5kW, the welding rate is 28mm / s, and the defocus amount is -1.2mm; the diameter of the welding spot is 0.6mm~0.7mm.

[0034] More specifically, the laser spot is offset by 0.1 mm toward the lower housing.

[0035] The present invention adopts the above technical solution and realizes continuous laser welding through a fiber laser welding machine, with high welding efficiency and stronger welding strength than the base material cold-rolled steel or hot-rolled steel; due to the high energy density of the laser beam, the molten metal liquid in the molten pool is fully fused and the cooling speed after welding is fast, so that the weld joint obtains a non-equilibrium structure with good toughness and a large number of dislocations, which effectively hinders the expansion of cracks during the tensile process, and the strength of the weld joint is higher than that of the base material cold-rolled steel or hot-rolled steel; at the same time, because the fiber laser welding machine forms a small and uniform weld joint on the periphery after forming a deep penetration around the shell, the appearance is neat and beautiful, and the generation of burrs is completely eliminated, thereby eliminating the need for a brushing process; in addition, fiber laser welding relies on the melting of its own shell plate to form a molten pool connection, eliminating the need for welding wire, and the thermal deformation area is small, thereby greatly reducing the damage of laser heat conduction to the pump body enclosed in the shell, reducing product costs, and improving product appearance quality and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a structural diagram of embodiment 1 of the present invention.

[0037] Figure 2 for Figure 1 a top view of the structure shown;

[0038] Figure 3 for Figure 2 A-A sectional view in FIG;

[0039] Figure 4 This is a schematic diagram of the melt height of Example 1 of the present invention;

[0040] Figure 5 This is a structural diagram of embodiment 2 of the present invention;

[0041] Figure 6 for Figure 5 A schematic cross-sectional view of the structure shown;

[0042] Figure 7 This is a schematic structural diagram of embodiment 3 of the present invention;

[0043] Figure 8 for Figure 7 A schematic cross-sectional view of the structure shown;

[0044] Figure 9 This is an overall schematic diagram of laser welding of the upper cover and lower shell of the present invention;

[0045] Figure 10 This is a schematic diagram of the method for obtaining the laser of the present invention.

[0046] The marks in the figure are:

[0047] 1. Upper cover, 2. Lower shell, 3. Welding seam, 4. Melt height, 5. Chamfer of lower shell stop, 6. R arc of lower shell stop, 7. Laser gun head. DETAILED DESCRIPTION

[0048] The specific implementation methods of the present invention will be further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0049] like Figures 1 to 8 The structure of the present invention is a laser-welded compressor housing, comprising a lower housing 2 and an upper cover 1 matched therewith.

[0050] The equipment for welding the upper and lower compressor casings consists of a laser, a robot, a chiller, an optical fiber, and a welding head. The laser uses a semiconductor located within the optical fiber, whose emission wavelength matches the absorption characteristics of the doped rare-earth element, as a pump source. The optical fiber end face generates laser light, which is then transmitted by the fiber. The robot, under control of the welding head, performs the laser welding. The fiber laser welder utilizes a slender, rare-earth-doped optical fiber as the laser gain medium, resulting in a very large surface-to-volume ratio and excellent heat dissipation.

[0051] The present invention utilizes laser focusing to generate high heat, instantly melting the shell plate into a reliable connection, with high production efficiency, small heat conduction deformation area, and beautiful welding appearance. It also eliminates the need for welding wire and brushing during welding, resulting in a simple process and reliable quality.

[0052] The laser used in the present invention is obtained as follows Figure 10 shown.

[0053] The laser is a strong single-color light emitted by a laser generator. Due to the monochromatic, concentrated, coherent and high-brightness characteristics of the laser beam, the energy per unit irradiation area can sometimes reach an astonishing 10 7 W / cm 2 , or even higher.

[0054] The compressor shell plate will begin to vaporize further as the hot metal's temperature instantly rises above its melting point. The metal vapor will further form a small hole called a keyhole in the entire molten shell metal. The shape of the keyhole is generally elongated. Therefore, after this material is formed, the laser beam will generally be reflected many times inside the entire keyhole, and these reflections will be further absorbed, so the penetration depth is increased.

[0055] The laser spot used for heating in the laser welding is centralized for welding the upper and lower shells, so that the upper and lower shell workpieces can meet the strength and appearance requirements of the welding under the premise of minimal radiation. The laser welding avoids deformation that is very easy to occur due to excessive heating of the processed workpiece.

[0056] In order to solve the problems existing in the prior art and overcome its defects, and to achieve the invention objectives of improving welding strength and production efficiency and making the appearance more beautiful, the present invention adopts the following specific embodiments:

[0057] Example 1:

[0058] like Figures 1 to 4 and Figure 9 Shown: A laser-welded compressor housing, in which the cross-section where the upper cover 1 and the lower housing 2 are connected is elliptical in shape; the upper cover 1 and the lower housing 2 are fitted with a stopper; the maximum clearance of the stopper fit is 0.5 mm.

[0059] The maximum penetration depth of the molten pool formed by the weld 3 between the upper cover 1 and the lower shell 2 is 1.8 mm, and the maximum height of the weld height 4 is 1.2 mm.

[0060] The height of the stopper is 8.5 to 9.5 mm. The stopper structure is used to ensure the position accuracy during the welding process.

[0061] The upper cover 1 forms a weld 3 through the fitting gap formed with the lower shell 2. When the fitting gap formed by the upper cover 1 and the lower shell 2 forms a weld 3 with a maximum value of 0.5 mm, the laser gun head 7 forms a focused high-energy laser spot through optical fiber pumping and conduction to melt the upper cover and the lower shell. The molten metal forms a molten pool at the weld 3. The upper cover 1 and the lower shell 2 are connected by the molten metal pool so that the metal liquid is fully fused and the cooling speed after welding is fast. The maximum penetration depth of the molten pool formed by the weld 3 is 1.8 mm, and the maximum height 4 is 1.2 mm. The metal liquid in the molten pool is fully fused and the cooling speed after welding is fast, forming a higher strength joint than the parent material cold-rolled steel or hot-rolled steel.

[0062] The compressor casing welding method adopts a fiber optic welder with a laser power of 3.0 to 3.5 kW and a welding rate of 30 mm / s; the defocus amount is -1 to -1.2 mm; the weld shielding gas is argon or nitrogen with a flow rate of 20 to 30 L / min; the welding spot is focused and adjusted by optical fiber transmission, and its diameter is 0.6 to 1.0 mm.

[0063] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0064] In order to achieve a maximum weld depth of 1.8 mm and a maximum weld height of 1.2 mm for the weld seam 3, and a joint with higher strength than the parent material cold-rolled steel or hot-rolled steel, the laser welding method for the upper and lower shells is as follows:

[0065] Under the control of a microprocessor, the voltage-stabilized laser power module provides a constant current for the fiber laser, which outputs a continuous laser of a fixed wavelength through a high-power laser diode. The laser beam is collimated and focused on the workpiece surface at the laser gun head 7 by operating the optical fiber. Under the control of a PLC or industrial PC, the CNC workbench is moved. The fiber laser welding power is 3.0 to 3.5 kW, the welding rate is 30 mm / s, the defocus is -1 to -1.2 mm, and the weld shielding gas is argon or nitrogen at 20 to 30 L / min. The welding spot can be adjusted through optical fiber conduction to a spot size of 0.6 to 1.0 mm after focusing.

[0066] More specifically, when the gap between the upper cover 1 and the lower shell 2 forming the weld 3 is 0.3mm, the fiber optic welder's laser power is 3.0kW, the welding rate is 25mm / s, the defocus is -1.0mm, and the welding spot diameter is 0.6mm to 0.7mm. The high-power density welding spot acts on the upper cover 1 and the lower shell 2 to form the material of the weld 3, causing it to evaporate and generating recoil pressure on the surface of the molten metal. This recoil pressure gradually decreases from the center of the spot toward the edge. The pressure differential drives the molten metal from the center of the beam toward the leading edge and rear of the weld 3, causing the liquid surface at the leading edge of the weld 3 to move in the welding direction. This results in a reliable, high-strength joint with a maximum penetration depth of 1.8mm and a maximum weld height 4 of 1.2mm in the weld 3.

[0067] Example 2:

[0068] like Figure 5 、 Figure 6 and Figure 9 As shown: A laser-welded compressor housing, including a lower housing 2 and an upper cover 1 that cooperates with it. The shape of the cross-section at the connection between the upper cover 1 and the lower housing 2 is elliptical; the upper cover 1 and the lower housing 2 are matched with a stopper; the maximum clearance of the stopper is 0.4mm; the edge of the lower housing 2 that cooperates with the upper cover 1 is provided with a lower housing stop chamfer 5 with a maximum depth not exceeding 1.2mm and a width not exceeding 0.15mm.

[0069] The maximum penetration depth of the molten pool formed by the weld 3 between the upper cover 1 and the lower shell 2 is 2.1 mm, and the maximum height of the weld height 4 is 1.5 mm.

[0070] The height of the stopper is 8.5 to 9.5 mm. The stopper structure is used to ensure the position accuracy during the welding process.

[0071] The upper cover 1 forms a weld seam 3 through the clearance formed with the lower shell 2. When the lower shell 2 has a maximum depth of no more than 1.2mm and a width of no more than 0.15mm chamfer, and the clearance between the upper cover 1 and the lower shell 2 forms a maximum weld seam 3 of 0.4mm, the laser gun head 7, through fiber pumping and conduction, creates a focused, high-energy laser spot that melts the upper cover 1 and the lower shell 2, forming a molten pool at the weld seam 3. The upper cover 1 and the lower shell 2 are fully fused in the molten pool, and the post-weld cooling rate is rapid, thus connecting the molten metals. The maximum weld depth of the molten pool formed by the weld seam 3 is 2.1mm, and the maximum weld height 4 is 1.5mm. Due to the full fusion of the metal liquid in the molten pool and the rapid post-weld cooling rate, a higher-strength joint is formed than that of the parent cold-rolled or hot-rolled steel.

[0072] The welding method for the compressor housing uses a fiber optic welder with a laser power of 3.0kW and a welding rate of 30mm / s; the defocus amount is -1mm; the weld shielding gas is argon or nitrogen, and its flow rate is 25L / min; the welding spot is focused and adjusted through optical fiber transmission, and its diameter is 0.6~0.9mm.

[0073] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0074] In order to achieve a maximum weld depth of 2.1 mm and a maximum weld height of 1.5 mm for the weld seam 3, and a joint with higher strength than the parent material cold-rolled steel or hot-rolled steel, the laser welding method for the upper and lower shells is as follows:

[0075] Under microprocessor control, the voltage-stabilized laser power module provides a constant current to the fiber laser, which then outputs a continuous laser beam of a fixed wavelength through a high-power laser diode. This laser beam is collimated and focused on the workpiece surface via the laser gun head 7, which is operated by an optical fiber. Under the control of a PLC or industrial PC, the CNC worktable is moved, and the gap between the upper and lower compressor shells is aligned to form the weld 3. When the weld 3 is a maximum of 0.4 mm, the fiber laser machine uses a laser power of 3.0 kW, a welding rate of 30 mm / s, a defocus of -1 mm, and a weld shielding gas of argon or nitrogen at 25 L / min. The weld spot can be adjusted to a focus of 0.6 to 0.9 mm through optical fiber transmission.

[0076] The high-power density welding spot acts on the upper cover 1 and lower shell 2, causing the material in weld 3 to evaporate and generate recoil pressure on the molten metal surface. This recoil pressure gradually decreases from the center of the spot toward the edges. This pressure differential drives the molten metal from the center of the beam toward the leading edge and rear of weld 3, causing the liquid surface at the leading edge of weld 3 to move in the welding direction. This results in a reliable, high-strength weld joint with a maximum penetration depth of 2.1mm and a maximum weld height 4 of 1.5mm.

[0077] Example 3:

[0078] like Figure 7 、 Figure 8 and Figure 9 As shown: A laser-welded compressor housing, including a lower housing 2 and an upper cover 1 that cooperates with it. The shape of the cross-section at the connection between the upper cover 1 and the lower housing 2 is elliptical; the upper cover 1 and the lower housing 2 are matched with a stopper; the maximum gap of the stopper is 0.4mm; the edge of the lower housing 2 that cooperates with the upper cover 1 is provided with a lower housing stop R arc 6 with a maximum depth not exceeding 1.4mm and a width not exceeding 0.15mm.

[0079] The maximum penetration depth of the molten pool formed by the weld 3 between the upper cover 1 and the lower shell 2 is 2.3 mm, and the maximum height of the weld height 4 is 1.6 mm.

[0080] The height of the stopper is 8.5 to 9.5 mm. The stopper structure is used to ensure the position accuracy during the welding process.

[0081] The upper cover 1 forms a weld 3 through the fitting gap formed with the lower shell 2. When the maximum depth of the stop of the lower shell 2 does not exceed 1.4mm and the width does not exceed 0.15mmR arc, when the fitting gap between the upper cover 1 and the lower shell 2 forms a weld 3 of a maximum of 0.4mm, the laser gun head 7 forms a focused high-energy laser spot through optical fiber pumping and conduction to melt the upper cover and the lower shell, and the molten metal forms a molten pool in the weld 3. The upper cover 1 and the lower shell 2 are connected by the molten metal pool so that the metal liquid is fully fused and the cooling speed after welding is fast. The maximum melting depth of the molten pool formed by the weld 3 is 2.3mm, and the maximum height 4 is 1.6mm. The metal liquid in the molten pool is fully fused and the cooling speed after welding is fast, forming a higher strength joint than the parent material cold-rolled steel or hot-rolled steel.

[0082] This compressor casing welding method includes the following steps: a voltage-stabilized laser power supply module, under the control of a microprocessor, provides a constant current to a fiber laser, which outputs a continuous laser beam of a fixed wavelength through a high-power laser diode. The laser beam is collimated and focused on the workpiece surface at a laser gun head 7 by operating an optical fiber. A CNC worktable is moved under the control of a PLC or industrial PC. The fiber optic welder used has a laser power of 3.0 kW and a welding rate of 28 mm / s. The defocusing amount is -1.2 mm. The weld shielding gas is argon or nitrogen at a flow rate of 28 L / min. The welding spot is focused and adjusted by optical fiber transmission, and its diameter is 0.6 to 1.0 mm.

[0083] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0084] Example 4:

[0085] like Figures 1 to 9 Shown: A laser-welded compressor housing, including a lower housing 2 and an upper cover 1 matched therewith, wherein the upper cover 1 and the lower housing 2 are made of different materials; the shape of the connecting cross section of the upper cover 1 and the lower housing 2 is elliptical; the upper cover 1 and the lower housing 2 are matched with a stopper; the maximum clearance of the stopper is 0.35 mm.

[0086] The maximum penetration depth of the molten pool formed by the weld 3 between the upper cover 1 and the lower shell 2 is 2.5 mm, and the maximum height of the weld height 4 is 1.6 mm.

[0087] The height of the stopper is 8.5 to 9.5 mm. The stopper structure is used to ensure the position accuracy during the welding process.

[0088] When the materials of the upper cover and the lower shell are inconsistent, the weld formed by the clearance between the upper and lower shells of the compressor is at most 0.35mm. The laser gun head 7 forms a focused high-energy laser spot through optical fiber pumping and conduction to melt the upper cover 1 and the lower shell 2. The molten metal forms a molten pool at the weld 3. The upper cover 1 and the lower shell 2 are connected by the molten metal pool so that the metal liquid is fully fused and the cooling speed is fast after welding. The maximum melting depth of the molten pool formed by the weld 3 is 2.5mm, and the maximum melting height 4 is 1.6mm. The metal liquid in the molten pool is fully fused and the cooling speed is fast after welding, forming a high-strength joint.

[0089] More specifically, the material of the upper cover 1 is aluminum alloy; the material of the lower shell 2 is hot-rolled steel plate or cold-rolled steel plate.

[0090] At this time, the laser power of the fiber optic welder used in the welding method of the compressor casing is 3.0~4.0kW, the welding rate is 30mm / s; the defocus amount is -1~-1.5mm; the weld shielding gas is argon or nitrogen, and its flow rate is 25~35L / min; the welding spot is focused by optical fiber conduction, and its diameter is 0.6~0.9mm.

[0091] When the upper cover 1 is an aluminum shell and the lower shell 2 is a hot-rolled plate or a cold-rolled plate, the gap between the upper and lower shells forms a weld with a maximum of 0.35mm, the weld 3 forms a maximum of 2.5mm, and the weld height is maximum 1.6mm, which ensures a high-strength connection. The laser welding method for the upper and lower shells is as follows:

[0092] Under the control of the microprocessor, the voltage-stabilized laser power module provides a constant current for the fiber laser, and outputs a continuous laser of a fixed wavelength through a high-power laser diode. The laser beam is collimated and focused on the workpiece surface at the laser gun head 7 by operating the optical fiber. Under the control of the PLC or industrial PC, the CNC workbench is moved. When the gap between the upper and lower shells of the compressor is matched to form a weld with a maximum gap of 0.35mm, the fiber laser power is 3.0-4.0kW, the welding rate is 30mm / s, the defocus is -1-1.5mm, and the weld shielding gas is argon or nitrogen at 25-35L / min.

[0093] In order to ensure that the center of the weld does not shift, the welding spot can be focused to 0.6-0.9 mm through optical fiber transmission adjustment, and the laser spot is offset to one side of the lower shell 2 by about 0.05-0.15 mm.

[0094] Preferably, the weld seam formed by the gap between the aluminum shell and the hot-rolled or cold-rolled plate is 0.3 mm, the laser power of the optical fiber welder is 3.5 kW, the welding rate is 28 mm / s, the defocus is -1.2 mm, and the welding focus adjustment is 0.6 mm to 0.9 mm. The laser spot is offset by about 0.10 mm toward the side of the lower shell 2.

[0095] The environment temperature of the shell laser welder is 5℃~40℃, the relative humidity is 45~85%RH, and the environmental cleanliness is air dust ≤0.05g / m 3 .

[0096] The high-power density welding spot acts on the aluminum upper cover 1 and lower shell 2, causing the material in weld 3 to evaporate and generate recoil pressure on the molten metal surface. This recoil pressure gradually decreases from the center of the spot toward the edges. This pressure differential drives the molten metal from the center of the beam toward the leading edge and rear of weld 3, causing the liquid surface at the leading edge of weld 3 to move in the welding direction. This results in a reliable, high-strength weld joint with a maximum penetration depth of 2.5mm and a maximum weld height 4 of 1.6mm.

[0097] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A laser welding method for a compressor housing, characterized in that: The compressor housing comprises a lower housing (2) and an upper cover (1) matched therewith; the cross section where the upper cover (1) and the lower housing (2) are connected is elliptical; the upper cover (1) and the lower housing (2) are matched with a stopper; the maximum clearance of the stopper is 0.5 mm; the height of the stopper is 8.5 to 9.5 mm; The laser welder is operated in an ambient temperature of 5°C to 40°C, a relative humidity of 45% to 85% RH, and an ambient cleanliness level of air dust ≤ 0.05g / m³. The weld shielding gas is argon or nitrogen, with a flow rate of 20 to 30L / min. The welding method uses a fiber optic welder with a laser power of 3.0 to 3.5 kW and a welding rate of 30 mm / s; a defocusing amount of -1 to -1.2 mm; and a welding spot with a diameter of 0.6 to 1.0 mm adjusted by optical fiber conduction. The maximum molten pool depth formed by the weld (3) between the upper cover (1) and the lower shell (2) is 1.8 mm, and the maximum molten pool height (4) is 1.2 mm.

2. A laser welding method for a compressor housing, characterized in that: The compressor housing comprises a lower housing (2) and an upper cover (1) matched therewith; the cross section where the upper cover (1) and the lower housing (2) are connected is elliptical; the upper cover (1) and the lower housing (2) are matched with a stopper; the maximum clearance of the stopper is 0.4 mm; the height of the stopper is 8.5 to 9.5 mm; The lower shell (2) is provided with a lower shell stop chamfer (5) on the edge that matches the upper cover (1) with a maximum depth of no more than 1.2 mm and a width of no more than 0.15 mm; The welding method uses a fiber optic welder with a laser power of 3.0kW and a welding rate of 30mm / s; a defocusing amount of -1mm; argon or nitrogen as the welding shielding gas, with a flow rate of 25L / min; and a welding spot with a diameter of 0.6 to 0.9mm, which is adjusted by optical fiber transmission and focus adjustment. The maximum depth of the molten pool formed by the weld (3) between the upper cover (1) and the lower shell (2) is 2.1 mm, and the maximum height of the molten pool (4) is 1.5 mm; The ambient temperature of the laser welder is 5℃~40℃, the relative humidity is 45%~85%RH, and the environmental cleanliness is air dust ≤0.05g / m³.

3. A laser welding method for a compressor housing, characterized in that: The compressor housing comprises a lower housing (2) and an upper cover (1) matched therewith; the cross section where the upper cover (1) and the lower housing (2) are connected is elliptical; the upper cover (1) and the lower housing (2) are matched with a stopper; the maximum clearance of the stopper is 0.4 mm; the height of the stopper is 8.5 to 9.5 mm; The lower shell (2) is provided with a lower shell stop R arc (6) on the edge that matches the upper cover (1) with a maximum depth not exceeding 1.4 mm and a width not exceeding 0.15 mm; The welding method uses a fiber optic welder with a laser power of 3.0 kW and a welding rate of 28 mm / s; The defocus is -1.2mm; the welding shielding gas is argon or nitrogen with a flow rate of 28L / min; the welding spot is focused and adjusted by optical fiber transmission, and its diameter is 0.6 to 1.0mm; The maximum molten pool depth formed by the weld (3) between the upper cover (1) and the lower shell (2) is 2.3 mm, and the maximum molten pool height (4) is 1.6 mm; The ambient temperature of the laser welder is 5℃~40℃, the relative humidity is 45%~85%RH, and the environmental cleanliness is air dust ≤0.05g / m³.

4. A laser welding method for a compressor housing, characterized in that: The compressor housing comprises a lower housing (2) and an upper cover (1) matched therewith; the upper cover (1) and the lower housing (2) are made of different materials; the cross section where the upper cover (1) and the lower housing (2) are connected is elliptical; the upper cover (1) and the lower housing (2) are matched with a stopper; the maximum clearance of the stopper is 0.35 mm; the height of the stopper is 8.5 to 9.5 mm; The material of the upper cover (1) is aluminum alloy; the material of the lower shell (2) is hot-rolled steel plate or cold-rolled steel plate; The laser welder is operated in an ambient temperature of 5°C to 40°C, a relative humidity of 45% to 85% RH, and an ambient cleanliness level of air dust ≤ 0.05g / m³. The weld shielding gas is argon or nitrogen, with a flow rate of 25 to 35L / min. The laser power of the optical fiber welder used in the welding method is 3.0-4.0 kW, the welding rate is 30 mm / s, the defocusing amount is -1--1.5 mm, the welding spot is focused by optical fiber transmission, and its diameter is 0.6-0.9 mm, and the laser spot is offset by 0.10 mm to one side of the lower shell (2); The fitting gap between the upper cover (1) and the lower shell (2) forms a weld (3), the maximum molten pool depth of the weld is 2.5 mm, and the maximum height of the weld height (4) is 1.6 mm.

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