Suction pipe and production process and application of welding in compressor main housing and liquid reservoir

Abstract

The present application relates to the technical field of steel pipe, in particular to a kind of suction pipe and production process and the application in the welding of compressor main casing and liquid accumulator, the production process of suction pipe includes the following steps: S1, material selection: select copper-iron composite plate as raw material;S2, copper-iron composite plate is continuously multi-stage stamping stretch forming: blanking, multi-stage stretching, flash, punching, chamfering, flaring, shaping.By multi-stage stretching, and control each level deep drawing coefficient and thinning coefficient, ensure that copper layer does not fall off under the premise of the end face of the barrel body is covered with copper layer, and production process is simple, easy for industrial production.The suction pipe prepared by the process, the second copper layer and the third copper layer directly cover the connecting surface and the bottom end surface of the barrel body welding contact respectively, form the barrel body end face copper, in the application of the welding of compressor main casing and liquid accumulator, significantly improve the metallurgical combination of pipe body and elbow during welding process, get appearance full, good sealing and good mechanical strength welding joint.

Description

Technical Field

[0001] This invention relates to the field of steel pipe technology, specifically to an intake pipe and its manufacturing process, and its application in welding compressor main housing and liquid receiver. Background Technology

[0002] In a refrigeration system, the connecting pipeline between the receiver and the compressor is a core component that ensures stable transmission of the system medium and efficient energy transfer. Its connection reliability, sealing performance, and electrical and thermal conductivity directly affect the operating efficiency and service life of the refrigeration system.

[0003] Currently, most suction pipes used for welding compressor main casings and liquid receivers employ a graded electroplating process to prepare functional copper layers on the inner surface of the pipe. However, this graded electroplating process requires depositing copper layers in different areas such as the inner wall of the cylinder and the connecting end faces in stages. Physical gaps are easily formed at the joints between the plating layers. Due to insufficient adhesion of the plating layers, plating peeling and cracking occur under the high-frequency vibration conditions of the compressor, seriously affecting the structural stability and service life of the connecting pipe.

[0004] To address the shortcomings of copper electroplating, a manufacturing process for compressor suction pipes has been disclosed in the prior art (patent application number: 201710441163.7). This process eliminates the traditional copper electroplating step and instead uses a direct stretching and forming method with copper-clad steel sheets to prepare the suction pipe. The stretching process achieves integrated forming of the pipe body and the copper layer, improving the bonding strength between the copper layer and the substrate to some extent. However, this technical solution has significant limitations: it only achieves copper layer coverage on the inner and outer walls of the pipe body, without a copper layer structure on the end face. When this suction pipe is used in a connection scenario between a liquid receiver and a compressor, the end face of the pipe body needs to be welded to the liquid receiver. Due to the lack of a copper layer on the end face, the metallurgical bonding between the base material and the solder is poor during welding, easily leading to defects such as bubbles and inclusions in the weld area. This results in insufficient sealing and mechanical strength of the weld joint, failing to meet the sealing requirements for high-pressure media transmission between the liquid receiver and the compressor. Furthermore, weld quality issues can cause risks such as refrigerant leakage and system malfunctions.

[0005] In addition, existing technologies do not emphasize the precise control of core parameters in the deep drawing process. They do not clearly define and coordinately optimize the deep drawing coefficient, thinning coefficient, and deep drawing blank holder force, and do not even mention the reasonable range of values ​​for the above parameters. They simply adopt conventional stretching processes, ignoring the forming characteristics of thin copper layer composite plates. Due to the lack of parameter control, defects such as copper layer peeling, cylinder cracking, and wrinkling are prone to occur during the stretching process, which further aggravates the structural instability of the suction pipe and makes it unsuitable for the operating conditions of refrigeration systems. Summary of the Invention

[0006] To overcome the shortcomings and deficiencies of existing technologies, the present invention aims to provide a manufacturing process for an intake pipe. Through multi-stage stretching and controlling the drawing and thinning coefficients at each stage, a copper layer is applied to the end face of the cylinder body without detachment. This process is simple and suitable for industrial production. The intake pipe produced by this process directly covers the welding contact surface and bottom end face of the cylinder body with a second and third copper layer, respectively, forming a copper-clad end face. In applications involving the welding of compressor main housings and liquid receivers, this significantly improves the metallurgical bonding between the pipe body and the bend during welding, resulting in a welded joint with a full appearance, good sealing, and high mechanical strength. Furthermore, the connecting pipe is sequentially inserted into the cylinder body through a through hole and a flared section, and the bend is inserted into the connecting pipe, forming a coaxial nested insertion structure. This facilitates assembly and, compared to traditional end-to-end welding, provides radial support between the cylinder body and the connecting pipe, and between the connecting pipe and the bend, enhancing the overall rigidity of the connection ends.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a manufacturing process for an inhalation tube, comprising the following steps: S1. Material Selection: Copper-iron composite plate is selected as the raw material; S2. Continuous multi-stage stamping and stretching forming of copper-iron composite plates: Step 1, Blanking: Use a blanking machine to stamp the copper-iron composite plate into blanks of a certain size and specification; Step 2, multi-stage stretching: The billet obtained in Step 1 is subjected to multi-stage stretching in sequence, and the drawing coefficient m and thinning coefficient φ are controlled at each stage to obtain a cylinder body with a copper layer covering the inner surface and a conical blank at the bottom. The end face of the cylinder body near the conical blank is covered with a copper layer. Step 3, flashing: Flashing is performed on the semi-finished product after multi-stage stretching in Step 2, and the conical excess material at the cylinder opening is removed; Step 4, Punching: Punching holes in the semi-finished product that has undergone the flash treatment in Step 3; Step 5, Chamfering: Chamfer the semi-finished product that has undergone punching in Step 4; Step 6, Flaring: Flaring the semi-finished product that has been chamfered in Step 5, so that the upper end of the cylinder has an integrally connected flared part; Step 7, Shaping: The semi-finished product that has undergone the flaring process in Step 6 is shaped to obtain the finished suction tube.

[0008] In this invention, by multi-stage stretching and controlling the drawing coefficient and thinning coefficient of each stage, the copper layer is covered with a copper layer on the end face of the cylinder near the conical scrap, while ensuring that the copper layer does not fall off. The conical scrap at the cylinder opening is then removed by flash trimming. The resulting cylinder end face is covered with a copper layer. The production process is simple and easy for industrial production.

[0009] Furthermore, the copper-iron composite plate is composed of an inner layer of copper plate and an outer layer of cold-rolled low-carbon steel plate. The thickness of the cold-rolled low-carbon steel plate layer is set to 1.0mm-2.0mm; the thickness of the copper plate layer is set to 0.01mm-0.1mm. The copper plate used is T2 copper plate, and the cold-rolled low-carbon steel plate is SPCE cold-rolled low-carbon steel plate. The copper-iron composite plate is obtained by rolling and annealing the copper plate and cold-rolled low-carbon steel plate together, achieving interatomic penetration and forming interatomic forces, making separation difficult. The bonding strength between the copper plate and the cold-rolled low-carbon steel plate in the resulting copper-iron composite plate is 180-250MPa.

[0010] Preferably, in the multi-stage stretching step of step two, the billet obtained in step one is subjected to 1-6 stages of stretching.

[0011] Preferably, low-temperature annealing is performed between multi-stage stretching, with an annealing temperature of 200-300℃ and an annealing time of 10-20 minutes, to eliminate work hardening and internal stress, restore material plasticity, and improve the adhesion of the copper layer to the cold-rolled low-carbon steel sheet.

[0012] Furthermore, in the multi-stage stretching step of step two, the drawing coefficient for each stage of stretching is 0.3-1, and the thinning coefficient is 0.64-1. The drawing coefficient is the ratio of the diameter d of the drawn cylindrical part to the diameter D of the blank (or the previous process) before stretching. The thinning coefficient is the ratio of the wall thickness t of the drawn tube to the wall thickness t0 of the blank (or the previous process) before stretching.

[0013] Furthermore, the drawing factor m and the thinning factor φ need to satisfy the following equation: (Formula 1); k is the safety factor, 0.4≤k≤1; m is the single drawing coefficient, 0.3≦m≦1; φ is the single-stage thinning coefficient, 0.64≦φ≦1; The drawing coefficient m and the thinning coefficient φ satisfy the following conditions: Among them, 0.3≦m≦1, 0.64≦φ≦1, and 0.4≤k≤1, the copper-iron composite plate deforms in a coordinated manner during the multi-stage deep drawing process, the copper layer is stably bonded to the cold-rolled low-carbon steel plate matrix, the copper layer is not easy to fall off or crack, and the forming quality is reliable.

[0014] Furthermore, in step two, four stages of deep drawing are performed sequentially, with the deep drawing coefficients for each stage being controlled as m1≈0.44, m2≈0.77, m3≈0.92, and m4≈0.76, and the thinning coefficients as φ1≈1.0, φ2≈0.9, φ3≈0.95, and φ4≈0.88, to obtain a cylinder body with a conical blank at the bottom, and the end face of the cylinder body near the conical blank is covered with a copper layer.

[0015] Furthermore, in the multi-stage stretching step of step two, a drawing die is used for stretching. The drawing die includes an upper die and a lower die located at the lower end of the upper die. The upper die includes an ejector device and a die located below the ejector device. The die is connected to the ejector device. The lower die includes a punch inserted into the die. The punch and die cooperate with each other to draw the blank into a cylindrical body. The ejector device is used to provide blank holder force.

[0016] Furthermore, the groove inside the die penetrates the die, and the ejector device communicates with the groove.

[0017] In this invention, an ejector device is installed in the upper die. Driven by an elastic element, the ejector device pre-clamps the flange area of ​​the blank before stretching. The ejection force provided by the ejector device is the blank holder force required for deep drawing. This not only reliably prevents the blank from wrinkling but also controls the material flow rate, ensuring uniform deformation and no interface peeling of the copper-iron composite plate during multi-stage stretching. This, in turn, ensures that the end face of the cylinder near the conical blank is stably covered with a copper layer. As the upper die moves downward, the ejector device in the upper die first contacts the flange area of ​​the blank and applies a clamping force to the blank under the action of the elastic element. This clamping force directly serves as the blank holder force. Subsequently, the die and punch cooperate to perform multi-stage stretching on the blank, gradually drawing the blank into a cylindrical structure. By controlling the drawing coefficient, thinning coefficient, and blank holder force at each stage, the copper layer and the iron base undergo synchronous plastic deformation.

[0018] Furthermore, the lower edge of the slot located on the lower end face of the die is rounded, that is, the bottom end face of the die and the inner wall of the die form a transition arc; the lower end of the punch is provided with a lower end head, and the outer wall of the punch and the upper end face of the lower end head are rounded, that is, the cylindrical surface of the punch and the bottom surface of the punch form a transition arc.

[0019] Furthermore, the fillet radius of the die cavity is Rd = 1.3t - 2.0t; the fillet radius of the punch is Rp = 1.0t - 1.7t, where t is the thickness of the copper-iron composite plate. If the fillet radius Rp of the punch is too small, the copper layer is easily torn or scratched; if the fillet radius Rd of the die cavity is too small, the copper layer is easily scratched, peeled off, or wrinkled.

[0020] The present invention also provides an air intake tube, which is manufactured according to the above-described air intake tube manufacturing process. The resulting air intake tube has good copper layer adhesion, and even after welding, rapid cooling after welding, flattening, and peeling after welding, the copper layer still has strong adhesion. Through multi-stage stretching and controlling the drawing coefficient, thinning coefficient, and edge pressure of each stage, the adhesion of the copper layer is not affected, ensuring that the copper layer does not fall off.

[0021] Furthermore, the suction pipe includes a cylindrical body and a flared portion integrally connected to the upper end of the cylindrical body. The inner wall of the cylindrical body and the inner wall of the flared portion are both provided with a first copper layer. The lower end of the cylindrical body is provided with a connecting surface that intersects with the bottom end face of the cylindrical body. The connecting surface is provided with a second copper layer. The bottom end face of the cylindrical body is provided with a third copper layer. The first copper layer, the second copper layer and the third copper layer are all integrally stamped and stretched with the cylindrical body and the flared portion.

[0022] The suction pipe of this invention has a simple structure. The inner wall of the cylinder has a first copper layer, the connecting surface has a second copper layer, and the bottom surface has a third copper layer, forming a three-dimensional surrounding welding surface. This achieves multi-contact and full-fit welding, significantly increasing the welding contact area and resulting in a more uniform welding fusion zone, avoiding problems such as localized incomplete welds and weld layer detachment. The first, second, and third copper layers provide excellent brazing layers for welding and are integrally stamped and stretched with the cylinder body and flared section, eliminating gaps and delamination caused by copper layer splicing or pasting. The copper layers have extremely strong adhesion to the substrate, preventing poor solder bonding due to copper layer peeling during welding and ensuring the sealing performance of the weld joint. The connecting surface and bottom end of the cylinder body form the end face of the cylinder body. The second and third copper layers are copper-clad end faces of the cylinder body, meaning the end face of the tube body is welded to the liquid receiver. Because of the copper layer on the end face, the metallurgical bonding between the tube body and the liquid receiver bend during welding is significantly improved, resulting in a welded joint with a full appearance, good sealing, and high mechanical strength. This effectively prevents media leakage within the refrigeration system and is suitable for high-pressure media transmission between the liquid receiver and the compressor. The one-piece molded first, second, and third copper layers reduce pre-treatment processes such as grinding and copper layer repair before welding, simplifying the assembly process of the liquid receiver and compressor and improving assembly efficiency on the production line. The one-piece molded connecting pipe structure has higher strength and can withstand the vibration and impact generated during compressor operation, avoiding the problems of weld cracking and loosening of connections caused by vibration in traditional spliced ​​suction pipes.

[0023] Furthermore, the angle between the connecting surface and the axis of the suction pipe is 25-45°.

[0024] Furthermore, the angle between the side wall of the flared portion and the axis of the cylinder body is 43-47°.

[0025] Furthermore, the axial length of the connecting surface is 0.5-2.5 mm.

[0026] Furthermore, the ratio of the axial height of the cylinder body to the axial height of the flared portion is 141-145:32.

[0027] Furthermore, the ratio of the diameter of the cylinder body to the maximum diameter of the flared portion is 130-136:65.

[0028] The present invention also provides an application of the above-mentioned suction pipe manufacturing process or the above-mentioned suction pipe in the welding of the compressor main housing and the liquid receiver. The compressor main housing is provided with a pump body and a connecting pipe connected to the pump body. The liquid receiver is provided with a bent pipe communicating with the liquid receiver. The flared part passes through the through hole and is placed inside the compressor main housing. The outer wall of the cylinder is welded to the surface of the compressor main housing. The connecting pipe passes through the flared part in sequence until it is inserted into the cylinder. The end of the bent pipe away from the liquid receiver extends into the cylinder and is inserted into the connecting pipe. A gap is left between the free end of the connecting pipe and the end of the cylinder away from the flared part. The second copper layer and the third copper layer are both welded to the outer wall of the bent pipe.

[0029] In this invention, the cylinder, connecting pipe, and bend cooperate with each other. The bend is inserted into the connecting pipe, and the connecting pipe is inserted into the cylinder through the through hole and the flared end in sequence, forming a coaxial nested insertion structure. This facilitates assembly and, compared to traditional end-to-end welding, the cylinder provides radial support to the connecting pipe, and the connecting pipe provides radial support to the bend, improving the overall rigidity of the connection ends. Simultaneously, a gap is left between the free end of the connecting pipe and the end of the cylinder furthest from the flared end. During welding, excess molten solder flows along the weld joint between the bend and the cylinder through the connecting surface to the gap. The connecting surface acts as a guide, preventing localized accumulation of weld beads. Excess solder flows along the weld joint to the gap and cools and solidifies within the gap, forming a continuous and thick fusion layer on the connecting surface and bottom welding area of ​​the bend and cylinder. This improves the connection stability between the cylinder and the bend, as well as the fullness of the weld.

[0030] Furthermore, the bend and connecting pipe are made of copper or copper-plated steel. The first, second, and third copper layers of the intake pipe are made of the same material as the copper or copper-plated layers of the bend and connecting pipe. This results in a stronger metallurgical bond between the two materials during welding, effectively avoiding defects such as weld embrittlement, porosity, and cracks that are prone to occur when welding dissimilar materials, and significantly improving the mechanical strength and structural stability of the welded joint.

[0031] The beneficial effects of this invention are: (1) The inner wall of the cylinder of the present invention is provided with a first copper layer, the connecting surface is provided with a second copper layer, and the bottom end is provided with a third copper layer to form a three-dimensional surrounding welding surface, which achieves multi-contact and full-fit welding with the outer wall of the bent pipe. Compared with the traditional single end face welding, the welding contact area is greatly increased, the welding fusion zone is more uniform, and the problems of local false welding and weld layer peeling are avoided.

[0032] (2) The first copper layer, the second copper layer and the third copper layer provide a good brazing layer for welding, and are integrally stamped and stretched with the cylinder body and the flared part. There are no gaps or delaminations in the splicing and pasting of the copper layer. The copper layer has a very strong bonding force with the substrate. During welding, there will be no poor solder bonding caused by copper layer peeling, ensuring the sealing performance of the weld.

[0033] (3) The cylinder body, connecting pipe and bend cooperate with each other. The bend is inserted into the connecting pipe, and the connecting pipe is inserted into the cylinder body through the through hole and the flared part in sequence, forming a coaxial nested insertion structure. This facilitates assembly. Compared with the traditional end-to-end welding, the cylinder body provides radial support to the connecting pipe and the connecting pipe provides radial support to the bend, which improves the overall rigidity of the connection ends of the three.

[0034] (4) A gap is left between the free end of the connecting pipe and the end of the cylinder away from the flared part. During welding, excess molten solder will flow along the weld between the bend and the cylinder through the connecting surface to the gap. At this time, the connecting surface plays a guiding role, avoiding the local accumulation of weld beads on the welding surface. The excess solder flows along the weld to the gap and completes cooling and solidification in the gap, so that the solder forms a continuous and thick fusion layer on the connecting surface and bottom end welding area of ​​the bend and the cylinder. This is beneficial to improving the connection stability between the cylinder and the bend, and also improves the fullness of the weld between the cylinder and the bend.

[0035] (5) The production process of the suction pipe of the present invention involves multi-stage stretching and controlling the stretching coefficient and thinning coefficient of each stage. Under the premise of ensuring that the copper layer does not fall off, the end face of the cylinder is covered with a copper layer. The resulting suction pipe has good copper layer adhesion. Even after welding, rapid cooling after welding, flattening, and peeling after welding, the copper layer still has strong adhesion. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the inhalation tube.

[0037] Figure 2 This is a schematic diagram of the connection structure of the liquid receiver, compressor, and connecting pipes.

[0038] Figure 3 This is a flowchart of the manufacturing process for the suction tube.

[0039] The reference numerals in the figures include: 1. Bend; 2. Main shell; 21. Through hole; 3. Connecting pipe; 4. Cylinder body; 41. Connecting surface; 5. Flared part; 6. Gap; 7. First copper layer; 8. Second copper layer; 9. Third copper layer. Detailed Implementation

[0040] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0041] In some embodiments, a manufacturing process for an inhalation tube includes the following steps: S1. Material Selection: Copper-iron composite plate is selected as the raw material; S2. Continuous multi-stage stamping and stretching forming of copper-iron composite plates: Step 1, Blanking: Use a blanking machine to stamp the copper-iron composite plate into blanks of a certain size and specification; Step 2, multi-stage stretching: The billet obtained in Step 1 is subjected to multi-stage stretching in sequence, and the drawing coefficient m and thinning coefficient φ are controlled at each stage to obtain a cylinder body with a copper layer covering the inner surface and a conical blank at the bottom. The end face of the cylinder body near the conical blank is covered with a copper layer. Step 3, flashing: Flashing is performed on the semi-finished product after multi-stage stretching in Step 2, and the conical excess material at the cylinder opening is removed; Step 4, Punching: Punching holes in the semi-finished product that has undergone the flash treatment in Step 3; Step 5, Chamfering: Chamfer the semi-finished product that has undergone punching in Step 4; Step 6, Flaring: Flaring the semi-finished product that has been chamfered in Step 5, so that the upper end of the cylinder has an integrally connected flared part; Step 7, Shaping: The semi-finished product that has undergone the flaring process in Step 6 is shaped to obtain the finished suction tube.

[0042] Furthermore, in the multi-stage stretching step of step two, the billet obtained in step one is subjected to 1-6 stages of stretching, preferably 4 stages of stretching.

[0043] Furthermore, in the multi-stage stretching step of step two, the drawing coefficient of each stage of stretching is 0.3-1, and the thinning coefficient is 0.64-1.

[0044] Furthermore, in the multi-stage stretching step of step two, a drawing die is used for stretching. The drawing die includes an upper die and a lower die located at the lower end of the upper die. The upper die includes an ejector device and a die located below the ejector device. The die is connected to the ejector device. The lower die includes a punch inserted into the die. The punch and die cooperate with each other to draw the blank into a cylindrical body. The ejector device is used to provide blank holder force.

[0045] Furthermore, the groove inside the die penetrates the die, and the ejector device communicates with the groove.

[0046] Furthermore, the lower edge of the slot located on the lower end face of the die is rounded, that is, the bottom end face of the die and the inner wall of the die form a transition arc; the lower end of the punch is provided with a lower end head, and the outer wall of the punch and the upper end face of the lower end head are rounded, that is, the cylindrical surface of the punch and the bottom surface of the punch form a transition arc.

[0047] Furthermore, the fillet radius of the die cavity is Rd = 1.3t - 2.0t; the fillet radius of the punch is Rp = 1.0t - 1.7t, where t is the thickness of the copper-iron composite plate. If the fillet radius Rp of the punch is too small, the copper layer is easily torn or scratched; if the fillet radius Rd of the die cavity is too small, the copper layer is easily scratched, peeled off, or wrinkled.

[0048] Example 1 like Figure 1-2 As shown, this embodiment provides an inhalation tube, which is manufactured according to the above-described inhalation tube manufacturing process.

[0049] Furthermore, the suction pipe includes a cylindrical body 4 and a flared portion 5 integrally connected to the upper end of the cylindrical body 4. The inner wall of the cylindrical body 4 and the inner wall of the flared portion 5 are both provided with a first copper layer 7. The lower end of the cylindrical body 4 is provided with a connecting surface 41 that intersects with the bottom end face of the cylindrical body 4. The connecting surface 41 is provided with a second copper layer 8. The bottom end face of the cylindrical body 4 is provided with a third copper layer 9. The first copper layer 7, the second copper layer 8 and the third copper layer 9 are all integrally stamped and stretched with the cylindrical body 4 and the flared portion 5. That is, the inner wall of the flared portion 55, the inner wall of the cylindrical body 44, the connecting surface 4141 and the bottom end face are all provided with copper layers, so that when the cylindrical body 44 and the flared portion 55 are integrally stretched and formed.

[0050] Furthermore, the angle between the connecting surface 41 and the axis of the suction pipe is 25-45°. During welding, the connecting surface 41 is inclined, allowing the molten filler metal to naturally penetrate downwards along the gap under gravity. Compared to a right angle or a small angle (less than 25°) connecting surface 41, this avoids the problem of filler metal stagnation and inability to fill the gap due to a vertical or excessively narrow gap. This angle also prevents the filler metal from flowing out too quickly due to a large angle (greater than 45°) connecting surface 41, allowing sufficient time for the filler metal to remain in the gap to complete wetting and spreading, ensuring a weld free of voids and slag inclusions. In this embodiment, the angle between the connecting surface 41 and the axis of the suction pipe is 30°.

[0051] Furthermore, the angle between the sidewall of the flared portion 5 and the axis of the cylinder body 4 is 43-47°, that is, the angle between the sidewall of the flared portion 5 and the surface of the compressor main housing 2 is 43-47°. This provides sufficient space for the molten solder during welding, and guides the solder to spread evenly along the inclined sidewall of the flared portion 5, avoiding solder accumulation or loss, and forming a continuous and dense weld. In this embodiment, the angle between the sidewall of the flared portion 5 and the axis of the cylinder body 4 is 45°. Simultaneously, the compressor main housing 2 is mostly a curved structure, allowing the inclined sidewall of the flared portion 5 to fit tightly against the compressor surface.

[0052] Furthermore, the axial length of the connecting surface 41 is 0.5-2.5mm. This provides sufficient space for the molten brazing filler metal, ensuring that the filler metal completely fills the gap between the connecting surface 41 and the side wall of the bend 1, without causing an increase in the amount of brazing filler metal used, weld accumulation, or insufficient heat concentration due to excessive length.

[0053] Furthermore, the ratio of the axial height of the cylinder body 4 to the axial height of the flared portion 5 is 141-145:32. This makes the center of gravity distribution of the connecting pipe 3 more reasonable. As the main load-bearing and connecting section, the higher proportion of axial height of the cylinder body 4 provides sufficient structural strength to resist high-frequency vibration and medium pressure impact during compressor operation; the moderate proportion of axial height of the flared portion 5 can meet the contact area requirements for welding with the compressor surface. In this embodiment, the ratio of the axial height of the cylinder body 4 to the axial height of the flared portion 5 is 143:32.

[0054] Furthermore, the ratio of the diameter of the cylindrical body 4 to the maximum diameter of the flared portion 5 is 130-136:65. In this embodiment, the ratio of the diameter of the cylindrical body 4 to the maximum diameter of the flared portion 5 is 133:65.

[0055] Example 2 This embodiment provides the application of the suction pipe of Embodiment 1 in the welding of the compressor main housing 2 and the liquid receiver. The compressor main housing 2 is provided with a pump body and a connecting pipe 3 connected to the pump body. The liquid receiver is provided with a bent pipe 1 communicating with the liquid receiver. The compressor main housing 2 has a through hole 21. The flared part 5 passes through the through hole 21 and is placed inside the compressor main housing 2. The outer wall of the cylinder 4 is welded to the surface of the compressor main housing 2. The connecting pipe 3 passes through the flared part 5 in sequence until it is inserted into the cylinder 4. The end of the bent pipe 1 away from the liquid receiver extends into the cylinder 4 and is inserted into the connecting pipe 3. A gap 6 is left between the free end of the connecting pipe 3 and the end of the cylinder 4 away from the flared part 5. The second copper layer 8 and the third copper layer 9 are both welded to the outer wall of the bent pipe 1.

[0056] Furthermore, the bend 1 and the connecting pipe 3 are copper pipes.

[0057] Furthermore, the welding process for the connecting surface 41 and bottom end face of the cylinder body 4 to the bend 1 is flame brazing, and the welding process for the flared part 5 to the liquid receiver compressor is also flame brazing. The workpieces to be welded are heated by a high-temperature flame, melting the solder and filling the weld gap with a length of at least 3.5 mm, resulting in a full and plump appearance. The solder selected is phosphor bronze solder.

[0058] Example 3 like Figure 3 As shown, this embodiment provides a manufacturing process for an inhalation tube, including the following steps: S1. Material Selection: Copper-iron composite plate is selected as the raw material; S2. Continuous multi-stage stamping and stretching forming of copper-iron composite plates: Step 1, Blanking: Use a blanking machine to stamp the copper-iron composite plate into blanks of a certain size and specification; Step 2, multi-stage stretching: The billet obtained in Step 1 is subjected to multi-stage stretching in sequence, and the drawing coefficient m and thinning coefficient φ are controlled at each stage to obtain a cylinder body with a copper layer covering the inner surface and a conical blank at the bottom. The end face of the cylinder body near the conical blank is covered with a copper layer. Step 3, flashing: Flashing is performed on the semi-finished product after multi-stage stretching in Step 2, and the conical excess material at the cylinder opening is removed; Step 4, Punching: Punching holes in the semi-finished product that has undergone the flash treatment in Step 3; Step 5, Chamfering: Chamfer the semi-finished product that has undergone punching in Step 4; Step 6, Flaring: Flaring the semi-finished product that has been chamfered in Step 5, so that the upper end of the cylinder has an integrally connected flared part; Step 7, Shaping: The semi-finished product that has undergone the flaring process in Step 6 is shaped to obtain the finished suction tube.

[0059] In this invention, by multi-stage stretching and controlling the drawing coefficient and thinning coefficient of each stage, the copper layer is covered with a copper layer on the end face of the cylinder near the conical scrap, while ensuring that the copper layer does not fall off. The conical scrap at the cylinder opening is then removed by flash trimming. The resulting cylinder end face is covered with a copper layer. The production process is simple and easy for industrial production.

[0060] Furthermore, the copper-iron composite plate is composed of an inner layer of copper plate and an outer layer of cold-rolled low-carbon steel plate. The thickness of the cold-rolled low-carbon steel plate layer is 1.5 mm, and the thickness of the copper plate layer is 0.05 mm. The total thickness of the composite plate is t = 1.55 mm. The copper plate used is T2 copper plate, and the cold-rolled low-carbon steel plate is SPCE cold-rolled low-carbon steel plate. The copper-iron composite plate is obtained by rolling the copper plate and cold-rolled low-carbon steel plate together and then annealing. The bonding strength between the copper plate and the cold-rolled low-carbon steel plate in the obtained copper-iron composite plate is 220 MPa.

[0061] Furthermore, low-temperature annealing is performed between multi-stage stretching at a temperature of 250°C for 15 minutes to eliminate work hardening and internal stress, restore material plasticity, and improve the adhesion of the copper layer to the cold-rolled low-carbon steel sheet.

[0062] Furthermore, the fillet radius of the die cavity is Rd = 1.6t; the fillet radius of the punch is Rp = 1.3t, where t is the thickness of the copper-iron composite plate. That is, the fillet radius of the die cavity in this embodiment is Rd = 2.5mm.

[0063] Furthermore, the drawing factor m and the thinning factor φ need to satisfy the following equation: (Formula 1); k is the safety factor, 0.4≤k≤1; m is the single drawing coefficient, 0.3≦m≦1; φ is the single-stage thinning coefficient, 0.64≦φ≦1; The drawing coefficient m and the thinning coefficient φ satisfy the following conditions: Among them, 0.3≦m≦1, 0.64≦φ≦1, and 0.4≤k≤1, the copper-iron composite plate deforms in a coordinated manner during the multi-stage deep drawing process, the copper layer is stably bonded to the cold-rolled low-carbon steel plate matrix, the copper layer is not easy to fall off or crack, and the forming quality is reliable.

[0064] Furthermore, in step two, four stages of deep drawing are performed sequentially, with the deep drawing coefficients for each stage being controlled as m1≈0.44, m2≈0.77, m3≈0.92, and m4≈0.76, and the thinning coefficients as φ1≈1.0, φ2≈0.9, φ3≈0.95, and φ4≈0.88, to obtain a cylinder body with a conical blank at the bottom, and the end face of the cylinder body near the conical blank is covered with a copper layer.

[0065] For the first stretch: Given parameters: drawing coefficient m1 = 0.44, thinning coefficient φ1 ≈ 1.0; Calculation result 1: k1=0.44, the process is stable, and the copper layer does not wrinkle or crack.

[0066] For the second stretch: Known parameters: drawing coefficient m2 = 0.77, thinning coefficient φ2 = 0.9; Calculation result 2: k2≈0.86, the process is stable, and the copper layer does not wrinkle or crack.

[0067] For the third stretch: Known parameters: drawing coefficient m3 = 0.92, thinning coefficient φ3 = 0.95; The calculated result 3: k3≈0.96, the process is stable, and the copper layer does not wrinkle or crack.

[0068] For the fourth stretch: Known parameters: drawing coefficient m4 = 0.76, thinning coefficient φ4 = 0.88; The calculated result 4: k4≈0.86, the process is stable, and the copper layer does not wrinkle or crack.

[0069] In this embodiment, the drawing coefficients of the four consecutive stretching operations are m1≈0.44, m2≈0.77, m3≈0.92, and m4≈0.76, all of which meet the requirement of 0.3≦m≦1; the thinning coefficients of the four consecutive stretching operations are φ1≈1.0, φ2≈0.9, φ3≈0.95, and φ4≈0.88, all of which meet the requirement of 0.64≦φ≦1; and the safety factors of the four consecutive stretching operations are k1≈0.44, k2≈0.86, and k3≈0. .96 and k4≈0.86 both meet the requirement of 0.4≤k≤1. Combined with the 220MPa bonding strength of the copper-iron composite plate and the thin copper layer structure, as well as the low-temperature annealing between multi-stage stretching, it is proven that the deep drawing process is stable and reliable. It can achieve continuous multi-stage stamping, stretching and plastic deformation, and the interface between the copper layer and the iron base is compacted and strengthened, maintaining a stable metallurgical bond. The copper layer does not peel off or crack, and at the same time, it effectively avoids defects such as wrinkling and cracking during the deep drawing process.

[0070] Comparative Example 1 Unlike Example 3, low-temperature annealing is not performed between multi-stage stretching.

[0071] The suction tubes prepared in Example 3 and Comparative Example 1 were subjected to copper adhesion tests, and the results are shown in Table 1: Table 1

[0072] Comparative Example 2 Unlike Example 3, the single drawing factor m is set to 0.25; the thinning factor φ is set to 0.55. The calculated result is: k≈0.45, indicating copper layer tearing.

[0073] When the drawing coefficient m < 0.3 and the thinning coefficient φ < 0.64, even if the following conditions are met... Furthermore, if 0.4≤k≤1, the copper layer may peel off due to excessive deformation and severe thinning of the copper layer.

[0074] Comparative Example 3 Unlike Example 3, the single drawing factor m was set to 0.27; the thinning factor φ was set to 0.7. The calculated result is: k=0.386, indicating slight cracking in the copper layer.

[0075] Comparative Example 4 Unlike Example 3, the single drawing factor m is set to 0.35; the thinning factor φ is set to 0.6. The calculated result is: k=0.583, indicating that the copper layer is wrinkling and cracking.

[0076] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A manufacturing process for an inhalation tube, characterized in that: Includes the following steps: S1. Material Selection: Copper-iron composite plate is selected as the raw material; S2. Continuous multi-stage stamping and stretching forming of copper-iron composite plates: Step 1, Blanking: Use a blanking machine to stamp the copper-iron composite plate into blanks of a certain size and specification; Step 2, multi-stage stretching: The billet obtained in Step 1 is subjected to multi-stage stretching in sequence, and the drawing coefficient and thinning coefficient of each stage are controlled to obtain a cylinder body with a copper layer covering the inner surface and a conical blank at the bottom. The end face of the cylinder body near the conical blank is covered with a copper layer. Step 3, flashing: Flashing is performed on the semi-finished product after multi-stage stretching in Step 2, and the conical excess material at the cylinder opening is removed; Step 4, Punching: Punching holes in the semi-finished product that has undergone the flash treatment in Step 3; Step 5, Chamfering: Chamfer the semi-finished product that has undergone punching in Step 4; Step 6, Flaring: Flaring the semi-finished product that has been chamfered in Step 5, so that the upper end of the cylinder has an integrally connected flared part; Step 7, Shaping: The semi-finished product that has undergone the flaring process in Step 6 is shaped to obtain the finished suction tube.

2. The manufacturing process of the suction tube according to claim 1, characterized in that: The copper-iron composite plate is composed of an inner layer of copper plate and an outer layer of cold-rolled low-carbon steel plate, wherein the thickness of the cold-rolled low-carbon steel plate layer is set to 1.0mm-2.0mm; and the thickness of the copper plate layer is set to 0.01mm-0.1mm.

3. The manufacturing process of the suction tube according to claim 1, characterized in that: In the second step of the multi-stage stretching process, the blank obtained in the first step is subjected to stretching of 1-6 stages.

4. The manufacturing process of the suction tube according to claim 1, characterized in that: In the multi-stage stretching step of step two, the stretching coefficient of each stage is 0.3-1, and the thinning coefficient is 0.64-1.

5. The manufacturing process of the suction tube according to claim 1, characterized in that: In the multi-stage stretching step of step two, a drawing die is used for stretching. The drawing die includes an upper die and a lower die located at the lower end of the upper die. The upper die includes an ejector device and a die located below the ejector device. The die communicates with the ejector device. The lower die includes a punch inserted into the die. The punch and die cooperate with each other to draw the blank into a cylindrical body. The ejector device is used to provide blank holder force.

6. The manufacturing process of the suction tube according to claim 1, characterized in that: The lower edge of the slot on the lower end face of the die is rounded; the lower end of the punch is provided with a lower head, and the outer wall of the punch and the upper end face of the lower head are rounded.

7. An inhalation tube, characterized in that: The inhalation tube is manufactured using the manufacturing process according to any one of claims 16.

8. The suction tube according to claim 7, characterized in that: The device includes a cylindrical body (4) and a flared portion (5) integrally connected to the upper end of the cylindrical body (4). The inner wall of the cylindrical body (4) and the inner wall of the flared portion (5) are both provided with a first copper layer (7). The lower end of the cylindrical body (4) is provided with a connecting surface (41) that intersects with the bottom end face of the cylindrical body (4). The connecting surface (41) is provided with a second copper layer (8). The bottom end face of the cylindrical body (4) is provided with a third copper layer (9). The first copper layer (7), the second copper layer (8) and the third copper layer (9) are all integrally stamped and stretched with the cylindrical body (4) and the flared portion (5).

9. The application of a suction pipe manufactured according to any one of claims 1-6 or the suction pipe according to claim 7 in the welding of a compressor main housing and a liquid receiver, wherein the compressor main housing (2) is provided with a pump body and a connecting pipe (3) connected to the pump body, and the liquid receiver is provided with a bent pipe (1) communicating with the liquid receiver, characterized in that: The compressor main housing (2) has a through hole (21). The flared part (5) passes through the through hole (21) and is placed inside the compressor main housing (2). The outer wall of the cylinder (4) is welded to the surface of the compressor main housing (2). The connecting pipe (3) passes through the flared part (5) in sequence until it is inserted into the cylinder (4). The end of the bent pipe (1) away from the liquid reservoir extends into the cylinder (4) and is inserted into the connecting pipe (3). A gap (6) is left between the free end of the connecting pipe (3) and the end of the cylinder (4) away from the flared part (5). The second copper layer (8) and the third copper layer (9) are both welded to the outer wall of the bent pipe (1).

10. The application of the suction pipe according to claim 9 in the welding of the compressor main housing and the liquid receiver, characterized in that, The bend (1) and connecting pipe (3) are copper pipes or copper-plated steel pipes.

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