Manufacturing method of solder-free double-tube liquid accumulator

Abstract

The invention discloses a manufacturing method of a solder-free double-tube liquid accumulator, and relates to the technical field of liquid accumulators, and the manufacturing method specifically comprises the following steps: stretching a circular steel sheet through a stretcher to form a cylindrical barrel with one sealed side and the other opened side in the axis direction; a first opening and a second opening are formed in the sealed side of the barrel in the radial direction; carrying out resistance welding on the first bent pipe with the first copper plating layer and the first open hole; carrying out resistance welding on the second bent pipe with the second copper plating layer and the second opening; a grooving machine provided with a middle plate is used for grooving the peripheral surface of the barrel, so that a first grooving position is formed in the barrel, and the middle plate is arranged in the first grooving position; a grooving machine provided with a filter screen is used for grooving the peripheral surface of the barrel, so that a second grooving position is formed in the barrel, and the filter screen is arranged in the second grooving position; spinning one side of the opening of the cylinder body to form a convex part which protrudes outwards in the axial direction and is provided with a third opening; and the air inlet pipe with the third copper plating layer is connected with the third opening through resistance welding.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of liquid reservoirs, and particularly relates to a manufacturing method of a solder-free double-pipe liquid reservoir. BACKGROUND

[0002] During operation of an air conditioning system, it cannot be guaranteed that all of the refrigerant is completely vaporized. If there is no liquid reservoir, part of the liquid refrigerant will enter the air conditioning compressor, causing damage to the air conditioning compressor. The compressor will cause liquid strike due to the suction of liquid refrigerant. Therefore, the liquid reservoir is usually arranged at the air conditioning evaporator and the suction pipe of the compressor. Specifically, during assembly, the air inlet pipe of the liquid reservoir is connected to the copper pipe of the air conditioning evaporator by welding, and the air outlet pipe of the liquid reservoir is connected to the copper pipe of the air conditioning compressor by welding. During operation, part of the liquid refrigerant in the liquid state is output from the air conditioning evaporator and enters the liquid reservoir. The liquid refrigerant that has not been vaporized directly falls to the bottom of the liquid reservoir due to its own weight, and the vaporized refrigerant enters the compressor from the outlet of the liquid reservoir, thereby preventing the compressor from sucking liquid refrigerant and causing liquid strike.

[0003] Therefore, in order to be connected to the copper pipe of the air conditioning evaporator and the copper pipe of the air conditioning compressor by welding, the air outlet pipe of the liquid reservoir is usually made of copper pipe. However, the cost of the copper pipe is high, and the tensile strength and rigidity of the copper pipe are poorer than those of the steel pipe. If the air outlet pipe is made of a full copper pipe, not only the production cost is greatly increased, but also the tensile strength and rigidity of the air outlet pipe are reduced. Since the liquid reservoir needs to have sufficient strength to withstand system pressure, vibration and possible accidental collision, in order to use a full copper pipe to connect to the outer pipe of the compressor and achieve the same connection strength, it is necessary to increase the radial size of the copper pipe. This not only increases the production cost but also increases the difficulty of processing and manufacturing, and the copper pipe is easily scratched and bumped by the outside world, reducing the service life. If a partial copper pipe is used, that is, a part of the steel pipe is connected to a copper pipe by welding, welding is required. During the welding process, welding rods, welding wires or solder are used to fill the welding material. This not only increases the welding points and increases the risk of cracks or cracking, but also makes it easier for the molten solder to wrap the gas and form pores. When the solder solidifies, the larger amount of liquid metal shrinks, which is more likely to cause shrinkage cavities and hot cracks. In addition, the molten connection of the solder will also reduce the connection strength between the parts.

[0004] In addition to the need for welding copper pipes, the traditional processing of the cylinder of the liquid accumulator and the connection between the cylinder and the gas inlet pipe and the gas outlet pipe also need to be welded by solder: among them, the cylinder of the liquid accumulator usually adopts a three-section structure, including upper and lower end covers and a middle cylinder, by welding the upper and lower end covers to the cylinder respectively, adding solder between the upper end cover and the cylinder for welding connection, and adding solder between the lower end cover and the cylinder for welding connection, resulting in more welds between the upper end cover and the cylinder and between the lower end cover and the cylinder, not only causing complex processing of parts, but also increasing the risk of stress concentration and cracking, easily leading to leakage points, gas leakage or liquid leakage, affecting the overall use of the liquid accumulator; among them, the welding connection between the liquid accumulator and the gas inlet pipe and between the liquid accumulator and multiple gas outlet pipes, due to uneven distribution of solder at the opening connection between the pipeline and the cylinder, the solder fails to fill the entire weld through capillary action, forming a discontinuous connection, which can seriously reduce the strength and sealing performance of the joint, and due to the sharp excessive angle at the connection between the weld and the base material, stress concentration easily occurs, cracks are generated, and the liquid accumulator leaks, resulting in a significant decrease in safety performance. SUMMARY

[0005] The present application provides a solder-free double-pipe liquid accumulator manufacturing method to solve the above technical problems. The tensile strength and stiffness of copper pipes are relatively poor compared to steel pipes, not only increasing production costs and the difficulty of processing and manufacturing, but also requiring the use of welding rods, welding wires or soldering tin and other fillers during the welding process, which not only increases the welding points and the risk of cracking or cracking, but also reduces the connection strength between parts; the cylinder of the liquid accumulator usually adopts a three-section structure, by welding the upper and lower end covers to the cylinder respectively, which also increases the use of solder, increases the risk of stress concentration and cracking, easily leads to leakage points, and affects the overall use of the liquid accumulator; the liquid accumulator and the gas inlet pipe or multiple gas outlet pipes are also welded, and the welds during the welding process can easily form a sharp excessive angle at the connection with the base material, which can easily cause stress concentration and cracks, leading to gas leakage or liquid leakage of the liquid accumulator, resulting in a significant decrease in safety performance.

[0006] The technical scheme adopted by the present application is: A solder-free double-pipe liquid accumulator manufacturing method, the specific steps are: S1: stretching a circular steel sheet into a cylindrical cylinder sealed on one side and open on the other side along the axial direction by a stretching machine; S2: opening a first opening and a second opening in the sealed side of the cylinder along the radial direction; S3: resistance welding a first elbow pipe with a first copper plating layer to the first opening; S4: resistance welding a second elbow pipe with a second copper plating layer to the second opening; S5: The groove machine with the middle plate grooves the outer circumferential surface of the cylinder body, so that the first groove position is formed on the cylinder body, and the middle plate is installed into the first groove position; S6: The groove machine with the filter screen grooves the outer circumferential surface of the cylinder body, so that the second groove position is formed on the cylinder body, and the filter screen is installed into the second groove position; S7: The open side of the cylinder body is spin formed to form a convex portion with a third opening hole, which protrudes outward in the axial direction; S8: The gas inlet pipe with the third copper plating layer is connected with the third opening hole through resistance welding.

[0007] In the assembly process of the liquid accumulator of the present application, no solder processing is required, thereby avoiding the connection performance decline, stress concentration and the risk of easy cracking and leakage caused by solder. Specifically, the liquid accumulator of the present application is first processed into a cylindrical cylinder-shaped structure by adopting an integral stretch forming circular steel sheet, thereby avoiding the problems of more welding points and higher leakage risk caused by the traditional method of forming the cylinder of the liquid accumulator by welding the three-section structure. Because the process of furnace brazing requires high energy consumption, ammonia gas is also consumed in production, which increases the potential safety risk and hidden danger. Moreover, after long-term use, the furnace brazing process is easily eroded or contaminated by the external environment, which causes quality problems of the cylinder part of the liquid accumulator, thereby affecting the normal use of the entire liquid accumulator and even the compressor, causing pollution or liquid strike of the compressor, and reducing the overall service life of the liquid accumulator and the compressor. Therefore, the cylinder of the present application has no welding points or welding seams, and no solder is required, thereby reducing the production process complexity, the number of structures or parts, and the production cost of the entire liquid accumulator, reducing the leakage points of the finished product, improving the safety performance and assembly precision of the liquid accumulator, avoiding injuries caused by furnace brazing or flame brazing by workers, and reducing the production energy consumption and risk coefficient, thereby improving the processing efficiency and processing quality of the entire liquid accumulator processing. Moreover, in order to realize the welding of the first bend pipe, the second bend pipe and the gas inlet pipe with the corresponding pipeline, the first bend pipe, the second bend pipe and the gas inlet pipe of the present application all adopt copper plating process, so that the first bend pipe, the second bend pipe and the gas inlet pipe have corresponding copper plating layers before assembly, thereby reducing the number of copper pipes used, avoiding the high production cost caused by welding copper pipes or using all copper pipes in the first bend pipe, the second bend pipe and the gas inlet pipe, and increasing the welding points of the pipeline. The increase of the welding points will change the geometry of the welding seam, causing sharp transition angles at the connection between the welding seam and the base material. These positions will become stress concentration points. When bearing load, especially dynamic load or fatigue load, cracks are prone to start and expand from these places, which greatly reduces the fatigue strength and overall structural integrity of the joint. The present application reduces the welding points, reduces the cracks and leakage points, and ensures the airtightness by forming the first bend pipe, the second bend pipe and the gas inlet pipe into an integral pipeline, thereby ensuring stable gas output and avoiding gas leakage.

[0008] As a preferred embodiment, in the step S3, before assembly, the first elbow pipe is bent inward by 90° at one end by turning and cold heading, so that the first elbow pipe forms a first straight section and a first bent section in the axial direction; the first bent section is subjected to copper plating processing to form a first copper plating layer.

[0009] Before assembly, the first elbow pipe of the present application is turned and cold headed to strengthen the stress intensity of the end of the first elbow pipe. At this time, the first elbow pipe is a straight structure. In order to realize a 90° bending of the first elbow pipe, facilitate the connection of the outer pipe of the compressor, the first elbow pipe forms a first bent section, the inner and outer surfaces of the first bent section are provided with a first copper plating layer, and the first copper plating layer is welded and connected with the outer pipe of the compressor, so that it is not necessary to use a copper pipe or a full copper pipe, thereby reducing the production complexity and production cost. Moreover, the first elbow pipe with the pre-prepared first copper plating layer can be directly assembled into the liquid accumulator, thereby forming a quick assembly, shortening the assembly working time, and improving the work efficiency.

[0010] As a preferred embodiment, in the step S3, one end of the first straight section is resistance welded with the first opening of the cylinder body; the first bent section extends out of the first opening and extends in the radial direction of the cylinder body.

[0011] The present application is resistance welded at one end of the first straight section and the first opening of the cylinder body, which can avoid the welding connection between the first straight section and the cylinder body, reduce the welding points, not only can enhance the connection strength between the first elbow pipe and the cylinder body, but also can reduce the leakage points between the cylinder body and the first elbow pipe caused by welding, avoid gas leakage; resistance welding is to pass positive and negative currents at the first straight section and the first opening part of the cylinder body, so as to realize the structure of melting one point of the cylinder body and melting one point of the first straight section, so that the cylinder body and the first straight section are mutually fused, so that the cylinder body and the first straight section are fully fused and connected, without external welding rod, welding wire or soldering tin as filler, which is easy to produce cracks or cracks, resulting in leakage points, and due to the melting and re-solidification of the workpiece itself, a stable cast structure of the fusion core is formed, the strength can be close to the strength of the base material, the tensile strength of the whole liquid accumulator is improved, the strength of the traditional welding material is lower than that of the base material, which can avoid the phenomenon of reducing the connection strength, the welding time of resistance welding is short, which can improve the welding efficiency while improving the connection strength.

[0012] As a preferred embodiment, the first copper plating layer is at least partially solidified on the inner and outer surfaces of the end of the outward end of the first bent section in the extension direction of the first bent section.

[0013] The first copper plating layer of the present application extends from the end of the outward end of the first bending section in the extension direction of the first bending section, so that the inner and outer surfaces of the first bending section are at least partially covered with the first copper plating layer, and the first bending section can also be entirely solidified with the first copper plating layer. The purpose is that the first bending section has a copper plating structure to facilitate connection with the outer pipe of the compressor, instead of the traditional copper pipe structure, which has a higher cost. If a partial copper pipe structure is used, welding connection is necessary, which not only increases the number of welding points and the risk of cracks and cracking, but also reduces the connection strength between components due to the use of more solder. If a full copper pipe structure is used, the production cost is inevitably increased. Moreover, the tensile strength and stiffness of the copper pipe are lower than those of the steel pipe. In order to use the copper pipe to connect with the outer pipe of the compressor to achieve the same connection strength, it is necessary to increase the radial size of the copper pipe, which not only increases the production cost but also increases the difficulty of processing and manufacturing. In addition, the accumulator needs sufficient strength to withstand system pressure, vibration and possible accidental collision. The use of a copper pipe will increase the risk of scratches and bumps, resulting in a reduction in the service life of the elbow pipe. The present application uses a full steel pipe for the first elbow pipe, which increases the tensile strength and stiffness of the first elbow pipe and improves the service life of the entire first elbow pipe and the accumulator. The use of copper plating can reduce the use of copper pipes. Copper plating ensures the uniformity and density of the weld, making it easier to pass the subsequent leak detection process, improving production efficiency and product qualification rate.

[0014] As a preferred embodiment, in step S4, the second elbow pipe is bent inward by 90° at one end before assembly by turning and cold heading, so that the second elbow pipe forms a second straight section and a second bending section in the axial direction; the second bending section is subjected to copper plating processing to form a second copper plating layer.

[0015] The second elbow pipe of the present application is formed by turning and cold heading before assembly, which strengthens the stress intensity of the end of the second elbow pipe. At this time, the second elbow pipe is a straight structure. In order to realize a 90-degree bending of the second elbow pipe and facilitate connection with the outer pipe of the compressor, the second elbow pipe forms a second bending section, and the inner and outer surfaces of the second bending section are provided with a second copper plating layer. The second elbow pipe is welded to the outer pipe of the compressor through the second copper plating layer, so that it is not necessary to use a welded copper pipe or a full copper pipe, thereby reducing production complexity and cost. Moreover, the second elbow pipe with the preformed second copper plating layer can be directly assembled into the accumulator, thereby forming rapid assembly, shortening the assembly time and improving work efficiency.

[0016] As a preferred embodiment, in step S4, the second straight section is resistance welded to the second opening of the cylinder body; the second bending section extends out of the second opening and extends in the radial direction of the cylinder body.

[0017] The second straight section of the application is resistance welded at one end with the second opening of the cylinder, which can avoid the welding connection between the second straight section and the cylinder, reduce the welding points, not only can enhance the connection strength between the second elbow pipe and the cylinder, but also can reduce the leakage points between the cylinder and the second elbow pipe caused by welding, avoid gas leakage; resistance welding is to pass positive and negative current at the second opening part of the second straight section and the cylinder, so that the structure of melting one point of the cylinder and melting one point of the second straight section can be realized, so that mutual melting between the cylinder and the second straight section occurs, so that the cylinder and the second straight section are fully fused and connected, without external welding rod, welding wire or soldering tin as filler, which is easy to produce cracks or cracks, resulting in leakage points, and due to the melting and solidification of the workpiece itself, a stable cast structure of the molten core is formed, the strength can approach the strength of the base material, improve the tensile strength of the whole liquid reservoir, avoid the phenomenon that the strength of the traditional solder is lower than that of the base material, resulting in reduced connection strength, the welding time of resistance welding is short, which can improve the connection strength and welding efficiency.

[0018] As a preferred embodiment, the second copper plating layer is at least partially solidified on the inner and outer surfaces of the second elbow section from the end of the outward end of the second elbow section in the extension direction of the second elbow section.

[0019] The second copper plating layer of the application extends from the end of the outward end of the second elbow section along the extension direction of the second elbow section, so that the inner and outer surfaces of the second elbow section are at least partially covered with the second copper plating layer, and the second elbow section can also be fully solidified with the second copper plating layer. The purpose is to facilitate the connection of the second elbow section with the outer pipe of the compressor by providing the second elbow section with a copper plating structure instead of the traditional copper pipe structure. The cost of copper pipe is relatively high, and if a partial copper pipe structure is used, welding connection is inevitable, which not only increases the number of welding points and the risk of cracking, but also reduces the connection strength between parts by using more solder. If a full copper pipe structure is used, the production cost will inevitably increase, and the tensile strength and stiffness of the copper pipe are lower than those of the steel pipe. In order to achieve the same connection strength between the copper pipe and the compressor outer pipe, the radial size of the copper pipe must be increased, which not only increases the production cost but also increases the difficulty of processing and manufacturing, and increases the risk of scratching and bumping, resulting in reduced service life of the elbow pipe. The second elbow pipe of the application is a full steel pipe, which increases the tensile strength and stiffness of the second elbow pipe and improves the service life of the entire second elbow pipe and liquid reservoir. The use of copper pipe is reduced by plating copper, which ensures the uniformity and density of the weld, making it easier to pass the subsequent leak detection process, improving production efficiency and product qualification rate.

[0020] As a preferred embodiment, in the step S8, the air inlet pipe is formed by turning and cold heading before assembly, and then subjected to copper plating treatment, so that the outward end of the air inlet pipe has a third copper plating layer.

[0021] The air inlet pipe of the present application is integrated with the steel pipe structure formed by turning and cold heading before assembly. Since the air inlet pipe is welded to the copper pipe of the air conditioner evaporator, the outward end of the air inlet pipe is subjected to copper plating process, and the outward end of the air inlet pipe has a third copper plating layer formed by at least partial copper plating structure, so as to ensure that the air inlet pipe has the super-high tensile strength and rigidity of the steel pipe, and has the at least partial copper plating structure for facilitating the welding connection with the copper pipe of the air conditioner evaporator. The present application can reduce the use of copper pipe by adopting copper plating, and the copper plating ensures the uniformity and density of the weld, so that the subsequent leak detection process is easier to pass, and the production efficiency and product qualification rate are improved.

[0022] As a preferred embodiment, the third copper plating layer is at least partially solidified on the inner and outer surfaces of the air inlet pipe along the axial direction of the air inlet pipe from the end of the outward end of the air inlet pipe.

[0023] The third copper plating layer of the present application is at least partially solidified on the inner and outer surfaces of the air inlet pipe along the extension direction of the air inlet pipe from the outward end of the air inlet pipe, so that the outward end of the air inlet pipe can form a copper plating structure for facilitating the connection with the copper pipe of the air conditioner evaporator. The copper pipe is resistance-welded to the third copper plating layer of the air inlet pipe, so that there is a dense metal barrier between the air inlet pipe and the copper pipe, which can reduce the amount of copper pipe used, and can also isolate the moisture and oxygen in the air between the air inlet pipe and the copper pipe, preventing corrosion. Moreover, the copper plating layer surface can easily spread the melted workpiece between the air inlet pipe and the copper pipe of the air conditioner evaporator, so that the melted base material can form a more uniform filling between the air inlet pipe and the air conditioner evaporator, thereby further enhancing the connection strength and welding quality between the air inlet pipe and the copper pipe of the air conditioner evaporator.

[0024] As a preferred embodiment, the step S2 further includes cleaning the cylinder to remove oil stains and impurities on the inner and outer surfaces.

[0025] The present application cleans the inside and outside of the cylinder after forming the cylinder structure, thereby effectively removing foreign matter inside the cylinder, avoiding damage to the subsequent liquid accumulator, avoiding the foreign matter from the liquid accumulator into the compressor to cause the compressor to be stuck, and thereby improving the operation safety performance of the entire liquid accumulator.

[0026] Thanks to the above technical solutions, the present application has the following advantages: In the assembly process of the liquid accumulator of the present application, no solder is used, and true solder-free processing can be achieved, thereby avoiding the connection performance degradation, stress concentration and risk of easy cracking and leakage caused by solder connection. Specifically, by adopting the structure of the integrally stretch-formed cylindrical barrel, the present application avoids the problems of more welding points and higher leakage risk caused by the traditional method of forming the barrel of the liquid accumulator by welding three sections together. The process of furnace brazing requires high energy consumption, and ammonia gas is also consumed in production, which increases the potential safety risks and hidden dangers. Moreover, after long-term use, the barrel part of the liquid accumulator is easily eroded or contaminated by the external environment, which affects the normal use of the entire liquid accumulator and even the compressor, causes pollution or liquid strike of the compressor, and reduces the overall service life of the liquid accumulator and the compressor. Therefore, the barrel of the present application has no welding points or seams, and no solder is used, thereby reducing the production process complexity, the number of structures or parts, and the production cost of the entire liquid accumulator, reducing the leakage points of the finished product, improving the safety performance and assembly precision of the liquid accumulator, avoiding injuries caused by furnace brazing or flame brazing by workers, reducing the production energy consumption and risk coefficient, thereby improving the processing efficiency and quality of the entire liquid accumulator processing. Moreover, in order to realize the welding of the first bend pipe, the second bend pipe and the gas inlet pipe with the corresponding copper pipe, the first bend pipe, the second bend pipe and the gas inlet pipe of the present application are all plated with copper, so that the first bend pipe, the second bend pipe and the gas inlet pipe have a corresponding copper plating layer before assembly, thereby reducing the number of copper pipes used, avoiding the high production cost caused by welding copper pipes or using all-copper pipes in the first bend pipe, the second bend pipe and the gas inlet pipe, and avoiding the use of solder, avoiding the increase of solder caused by traditional welded copper pipes. The increase of welding points will change the geometry of the weld, causing sharp transition angles at the connection between the weld and the base material. These positions will become stress concentration points. When subjected to load, especially dynamic load or fatigue load, cracks are prone to start and expand from these places, greatly reducing the fatigue strength and overall structural integrity of the joint. The present application integrally forms the first bend pipe, the second bend pipe and the gas inlet pipe into a pipe, reduces the welding points and cracks, reduces the leakage points, ensures the airtightness, thereby ensuring stable gas output and avoiding gas leakage. The first bending pipe, the second bending pipe and the gas inlet pipe are integrally formed respectively, the concentricity between the first bending section and the first linear section of the first bending pipe and the concentricity between the second bending section and the second linear section are ensured, the first linear section part can be completely inserted into the electrode in a welding manner, so that the welding position of the first linear section and the motor are completely contacted, the welding quality and strength between the first bending pipe and the cylinder are improved, and the detection processes such as water elimination inspection and air tightness detection process can be reduced. The whole production process is solder-free, the production process is more environmentally friendly, the resistance welding method is used to avoid the use of solder, the copper plating process is used for the first bending pipe, the second bending pipe and the gas inlet pipe, the welding copper pipe or the whole copper pipe is avoided, the use of solder is avoided, and the use amount of the copper pipe is reduced. The whole bending pipe uses the copper pipe, the production cost is increased, the tensile strength and the rigidity of the whole copper pipe are greatly lower than those of the steel pipe, in order to achieve the same connection strength, the radial size of the copper pipe is increased, the production cost and the manufacturing difficulty are increased, the risk of scratching and knocking of the copper pipe is increased, and the service life of the bending pipe is reduced. The whole steel pipe is used in the application, the connection strength of the liquid accumulator bending pipe is increased, the reliability of deformation resistance and knocking is improved, and the service life of the whole liquid accumulator is improved. In addition, the use of the hydraulic equipment, the furnace brazing equipment, the flame brazing equipment and the forging equipment can be reduced, the production cost is reduced, the safety hidden danger is reduced, the production of the liquid accumulator is more efficient and safe. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings described herein are used to provide further understanding of the application, constitute a part of the application, the schematic embodiments of the application and the description thereof are used to explain the application, and do not constitute improper limitation on the application. In the drawings: Figure 1 A cross-sectional structure diagram of a cylinder processed in steps S1 and S2 in a manufacturing method of a solder-free double-pipe liquid accumulator according to an embodiment of the application; Figure 2 A structure schematic diagram of a cylinder processed in step S4 in a manufacturing method of a solder-free double-pipe liquid accumulator according to an embodiment of the application; Figure 3 A cross-sectional structure schematic diagram of a cylinder processed in step S5 in a manufacturing method of a solder-free double-pipe liquid accumulator according to an embodiment of the application; Figure 4 A cross-sectional structure schematic diagram of a cylinder processed in step S6 in a manufacturing method of a solder-free double-pipe liquid accumulator according to an embodiment of the application; Figure 5 A cross-sectional structure schematic diagram of a cylinder processed in step S7 in a manufacturing method of a solder-free double-pipe liquid accumulator according to an embodiment of the application; Figure 6Figure 8 is a schematic view of the cross-sectional structure after step S8 of the manufacturing method of the solderless double-tube liquid reservoir according to an embodiment of the present application; Figures, 1, cylinder body; 2, first elbow; 21, first straight section; 22, first bending section; 3, second elbow; 31, second straight section; 32, second bending section; 4, middle plate; 5, filter screen; 6, first slotting position; 7, second slotting position; 8, protruding part; 9, third opening; 10, first copper plating layer; 11, second copper plating layer; 12, third copper plating layer; 13, air inlet pipe. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the overall concept of the present application, the following detailed description is given with reference to the accompanying drawings.

[0029] In the following description, a number of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced without the specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the present application.

[0030] In addition, in the description of the present application, it should be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0031] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected, or it can be communicated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0032] In the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. In the description of the present specification, the description referring to the terms "embodiment", "example", "one embodiment", "exemplary" or "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0033] The present application relates to a method for manufacturing a solderless double-tube liquid reservoir, as shown in Figures 1-6 The specific steps are as follows: S1: A circular steel sheet is stretched by a stretching machine to form a cylindrical barrel 1 sealed on one side and open on the other side along the axial direction; S2: A first opening and a second opening are formed on the sealed side of the barrel 1 in the radial direction; S3: A first bent pipe 2 with a first copper plating layer 10 is resistance welded with the first opening; S4: A second bent pipe 3 with a second copper plating layer 11 is resistance welded with the second opening; S5: A slotting machine with a middle plate 4 slots the outer circumferential surface of the barrel 1 to form a first slotting position 6 on the barrel 1, and the middle plate 4 is installed in the first slotting position 6; S6: A slotting machine with a filter screen 5 slots the outer circumferential surface of the barrel 1 to form a second slotting position 7 on the barrel 1, and the filter screen 5 is installed in the second slotting position 7; S7: The open side of the barrel 1 is spin formed to form a protruding portion 8 with a third opening 9 protruding outward in the axial direction; S8: A gas inlet pipe 13 with a third copper plating layer 12 is connected to the third opening 9 by resistance welding.

[0034] In the liquid accumulator assembly process of the present application, no solder is used, and true solder-free processing can be achieved, thereby avoiding the connection performance degradation, stress concentration and risk of easy cracking and leakage caused by solder. Specifically, the present application processes a cylindrical body 1-shaped structure by using an integrally stretch-formed circular steel sheet, avoiding the traditional three-section structure mutual welding method for forming the cylinder 1 of the liquid accumulator, which brings more welding points and higher leakage risk. Because the furnace brazing process requires high energy consumption, ammonia gas is also consumed in production, increasing potential safety risks and hidden dangers, and after long-term use, it is easy to be eroded or contaminated by the external environment, causing quality problems in the cylinder 1 part of the liquid accumulator, affecting the normal use of the entire liquid accumulator and even the compressor, causing the compressor to be contaminated or liquid strike, and reducing the overall service life of the liquid accumulator and the compressor. Therefore, the cylinder 1 of the present application has no welding points or seams, and does not need to use solder, thereby reducing the production process complexity, the number of structures or parts, and the production cost of the entire liquid accumulator, reducing the leakage points of the finished product, improving the safety performance and assembly precision of the liquid accumulator, avoiding injuries caused by furnace brazing or flame brazing by workers, and reducing production energy consumption and risk coefficient, thereby improving the processing efficiency and processing quality of the entire liquid accumulator processing. Moreover, in order to realize the welding of the first bend pipe 2, the second bend pipe 3 and the gas inlet pipe 13 with the corresponding pipeline, the first bend pipe 2, the second bend pipe 3 and the gas inlet pipe 13 of the present application all adopt a copper plating process, so that the first bend pipe 2, the second bend pipe 3 and the gas inlet pipe 13 have a corresponding copper plating layer before assembly, thereby reducing the number of copper pipes used, avoiding the high production cost caused by welding copper pipes or using all copper pipes in the first bend pipe 2, the second bend pipe 3 and the gas inlet pipe 13. Welding copper pipes will increase the welding points of the pipeline, and the increase of the welding points will cause the weld to change the geometry of the joint, causing a sharp transition angle at the connection between the weld and the base material. These positions will become stress concentration points. When subjected to load, especially dynamic load or fatigue load, cracks are extremely easy to start and expand from these places, greatly reducing the fatigue strength and overall structural integrity of the joint. The present application integrally forms the first bend pipe 2, the second bend pipe 3 and the gas inlet pipe 13 into a pipeline, respectively, to reduce welding points, reduce cracks and reduce leakage points, thereby ensuring airtightness and stable gas output, avoiding gas leakage.

[0035] In step S1 described above, the specific process of stretching a circular steel sheet to form a cylindrical body 1 with one side sealed and the other side open along the axial direction using a stretching machine is as follows: First, a stamping machine stamps the steel plate material to form a circular steel sheet. Then, the circular steel sheet is placed on a die, and the pressure ring descends to press it tightly with a certain force. Then, the punch begins to move downward, contacting the center of the circular steel sheet and applying pressure. Under the combined action of the punch pressure and the rounded corner of the die, the center first bends and is then forcibly pulled into the die hole. At this time, the flange portion of the circular steel sheet, that is, the annular area under the pressure ring, begins to shrink radially towards the center. The pressure ring is located above the die and is used to press the annular component at the edge of the circular steel sheet. The punch continues to descend, and the flange portion of the blank continues to flow into the die hole and wraps around the punch, gradually forming the side wall of the pen holder. In this process, the diameter of the blank decreases and the height increases. When the punch reaches the bottom dead center, the blank is completely pulled into the die, forming a pen holder-like cylindrical body 1 with a sealed bottom and an open top.

[0036] In a preferred embodiment, in step S3, before assembly, the first bent pipe 2 is formed by turning and cold heading, and one end is bent inward by 90°, so that the first bent pipe 2 forms a first straight segment 21 and a first bent segment 22 in the axial direction; the first bent segment 22 is copper plated to form a first copper plating layer 10.

[0037] Before assembly, the first bend 2 of this application is formed by turning and cold forging to enhance the strength of its end. At this point, the first bend 2 is a straight structure. To achieve a 90-degree bend for easy connection to the compressor's outer pipe, the first bend 2 forms a first bent section 22. The inner and outer surfaces of the first bent section 22 are provided with a first copper plating layer 10. The first copper plating layer 10 is used to weld the first bend 22 to the compressor's outer pipe, thus eliminating the need for welded copper pipes or all-copper pipes, reducing production complexity and costs. Furthermore, the pre-fabricated first bend 2 with the first copper plating layer 10 allows it to be directly assembled into the liquid receiver, enabling rapid assembly, shortening assembly time, and improving work efficiency.

[0038] In a preferred embodiment, in step S3, one end of the first straight segment 21 is resistance welded to the first opening of the cylinder 1; as shown Figure 2 As shown, the first curved section extends beyond the first opening and extends radially along the cylinder 1.

[0039] One end of the first straight section 21 of the present application is resistance welded with the first opening of the cylinder body 1, which can avoid the welding connection between the first straight section 21 and the cylinder body 1, reduce the welding points, not only can enhance the connection strength between the first elbow pipe 2 and the cylinder body 1, but also can reduce the leakage points between the cylinder body 1 and the first elbow pipe 2 caused by welding, avoid gas leakage; resistance welding is to pass positive and negative current to the first straight section 21 and the first opening part of the cylinder body 1, so that the structure of melting one point of the cylinder body 1 and melting one point of the first straight section 21 can be realized, so that the cylinder body 1 and the first straight section 21 are mutually fused, so that the cylinder body 1 and the first straight section 21 are fully fused and connected, without external welding rod, welding wire or soldering tin and other welding materials as filler, which is easy to produce cracks or cracks, resulting in leakage points, and due to the melting and solidification of the workpiece itself, a stable cast structure of the fusion core is formed, the strength can be close to the strength of the base material, the tensile strength of the whole liquid reservoir is improved, the phenomenon that the strength of the traditional welding material is lower than that of the base material, resulting in the decrease of the connection strength, the welding time of resistance welding is short, which can improve the connection strength and welding efficiency.

[0040] As a preferred embodiment, the first copper plating layer 10 is at least partially solidified on the inner and outer surfaces of the first bending section 22 along the extension direction of the first bending section 22 from the end of the outward end of the first bending section 22.

[0041] The first copper plating layer 10 of the present application extends from the end of the outward end of the first bending section 22 along the extension direction of the first bending section 22, so that the inner and outer surfaces of the first bending section 22 are at least partially covered with the first copper plating layer 10, and the first bending section 22 can also be entirely solidified with the first copper plating layer 10. The purpose is to facilitate the connection of the first bending section 22 with the outer pipe of the compressor by providing the first bending section 22 with a copper plating structure, instead of the traditional copper pipe structure. The copper pipe has a high cost, and if a partial copper pipe structure is used, welding connection is necessary, which not only increases the number of welding points and the risk of cracks and breakage, but also reduces the connection strength between components due to the use of more solder. If a full copper pipe structure is used, the production cost will inevitably increase, and the tensile strength and stiffness of the copper pipe are lower than those of the steel pipe. In order to use the copper pipe to connect with the outer pipe of the compressor to achieve the same connection strength, it is necessary to increase the radial size of the copper pipe, which not only increases the production cost but also increases the difficulty of processing and manufacturing. In addition, the accumulator needs sufficient strength to withstand system pressure, vibration, and possible accidental collisions. The use of a copper pipe will increase the risk of scratches and bumps, reducing the service life of the elbow pipe. The present application uses a full steel pipe for the first elbow pipe 2, which increases the tensile strength and stiffness of the first elbow pipe 2 and improves the service life of the entire first elbow pipe 2 and the accumulator. The present application can reduce the use of copper pipes by using copper plating, which ensures the uniformity and density of the weld, making it easier to pass the subsequent leak detection process, improving production efficiency and product qualification rate.

[0042] As a preferred embodiment, in the step S4, the second elbow pipe 3 is bent inward by 90° at one end after turning and cold heading before assembly, so that the second elbow pipe 3 forms a second straight section 31 and a second bending section 32 in the axial direction; the second bending section 32 is subjected to copper plating processing to form a second copper plating layer 11.

[0043] The second elbow pipe 3 of the present application is subjected to turning and cold heading before assembly, which strengthens the stress intensity of the end of the second elbow pipe 3. At this time, the second elbow pipe 3 is in a straight structure. In order to realize a 90-degree bending of the second elbow pipe 3 and facilitate the connection with the outer pipe of the compressor, the second elbow pipe 3 forms a second bending section 32, and the inner and outer surfaces of the second bending section 32 are provided with a second copper plating layer 11. The second elbow pipe 3 is welded to the outer pipe of the compressor through the second copper plating layer 11, so that it is not necessary to use a welded copper pipe or a full copper pipe, thereby reducing production complexity and cost. Moreover, the second elbow pipe 3 with the preformed second copper plating layer 11 can be directly assembled into the accumulator, thereby forming a quick assembly, shortening the assembly time and improving work efficiency.

[0044] The purpose of designing the first elbow pipe 2 and the second elbow pipe 3 as 90-degree bends is that if the inlet and outlet pipes of the liquid reservoir are designed as straight, they will stretch out like two spears, occupy a large space, and may interfere with the installation of other components and the layout of the pipelines. By bending the pipes by 90 degrees, the pipes can be closely arranged along the liquid reservoir tank body or other components, greatly reducing the occupied projection space, and making the layout of the entire system more reasonable and compact.

[0045] As a preferred embodiment, in the step S4, one end of the second straight section 31 is resistance-welded to the second opening of the cylinder body 1. Figure 2 and Figure 3 As shown, the second curved section extends out of the second opening and extends in the radial direction of the cylinder body 1.

[0046] The resistance welding of one end of the second straight section 31 to the second opening of the cylinder body 1 can avoid the welding connection between the second straight section 31 and the cylinder body 1, reduce the welding points, not only enhance the connection strength between the second elbow pipe 3 and the cylinder body 1, but also reduce the leakage points between the cylinder body 1 and the second elbow pipe 3 caused by welding, and avoid gas leakage. Resistance welding is to pass positive and negative currents to the second straight section 31 and the second opening part of the cylinder body 1, so as to realize the structure of melting one point of the cylinder body 1 and melting one point of the second straight section 31, so that the cylinder body 1 and the second straight section 31 are mutually fused, and the cylinder body 1 and the second straight section 31 are fully fused and connected. No external welding rod, welding wire or soldering tin is needed as a filler, which is easy to produce cracks or cracks, resulting in leakage points. Moreover, due to the melting and re-solidification of the workpiece itself, a stable cast structure of the fusion core is formed, the strength can approach the strength of the base material, the tensile strength of the entire liquid reservoir is improved, the strength of the traditional solder is lower than that of the base material, which reduces the connection strength. The welding time of resistance welding is short, which can improve the connection strength and welding efficiency.

[0047] As a preferred embodiment, the second copper plating layer 11 is at least partially solidified on the inner and outer surfaces of the second curved section 32 from the end of the outward end of the second curved section 32 in the extension direction of the second curved section 32.

[0048] The second copper plating layer 11 of the present application extends from the end of the outward end of the second bending section 32 along the extension direction of the second bending section 32, so that the inner and outer surfaces of the second bending section 32 are at least partially covered with the second copper plating layer 11, and the second bending section 32 can also be entirely solidified with the second copper plating layer 11, so that the second bending section 32 has a copper plating structure to facilitate connection with the outer pipe of the compressor, instead of the traditional copper pipe structure, which has a high cost. If a partial copper pipe structure is used, welding connection is necessary, which not only increases the number of welding points and the risk of cracks and breakage, but also reduces the connection strength between components due to the use of more solder. If a full copper pipe structure is used, the production cost is inevitably increased, and the tensile strength and stiffness of the copper pipe are lower than those of the steel pipe. In order to use the copper pipe to connect with the compressor outer pipe to achieve the same connection strength, it is necessary to increase the radial size of the copper pipe, which not only increases the production cost but also increases the difficulty of processing and manufacturing, and increases the risk of scratching and bumping, thereby reducing the service life of the elbow pipe. The second elbow pipe 3 of the present application is a full steel pipe, which increases the tensile strength and stiffness of the second elbow pipe 3 and improves the service life of the entire second elbow pipe 3 and the liquid accumulator. The use of copper pipe is reduced by using copper plating, which ensures the uniformity and density of the weld, making it easier to pass the subsequent leak detection process, improving production efficiency and product qualification rate.

[0049] As a preferred embodiment, in step S8, the air inlet pipe 13 is formed by turning and cold heading before assembly, and then subjected to copper plating treatment, so that the outward end of the air inlet pipe 13 has a third copper plating layer 12.

[0050] The air inlet pipe 13 of the present application is an integrated steel pipe structure formed by turning and cold heading before assembly. Since the air inlet pipe 13 is welded to the copper pipe of the air conditioner evaporator, the outward end of the air inlet pipe 13 is subjected to copper plating process to form a third copper plating layer 12 with at least partial copper plating structure, so as to ensure that the air inlet pipe 13 has ultra-high tensile strength and stiffness of steel pipe, and also has at least partial copper plating structure for easy welding connection with the copper pipe of the air conditioner evaporator. The use of copper pipe is reduced by using copper plating, which ensures the uniformity and density of the weld, making it easier to pass the subsequent leak detection process, improving production efficiency and product qualification rate.

[0051] As a preferred embodiment, the third copper plating layer 12 is at least partially solidified on the inner and outer surfaces of the air inlet pipe 13 along the axis direction of the air inlet pipe 13 from the end of the outward end of the air inlet pipe 13.

[0052] The third copper plating layer 12 of the present application is at least partially solidified on the inner and outer surfaces of the air inlet pipe 13 from the outward end of the air inlet pipe 13 along the extension direction of the air inlet pipe 13, so that the outward end of the air inlet pipe 13 can form a copper plating structure to facilitate connection with the copper pipe of the air conditioner evaporator. The copper pipe is connected with the third copper plating layer 12 of the air inlet pipe 13 through resistance welding, so that there is a dense metal barrier between the air inlet pipe 13 and the copper pipe, which can not only reduce the use amount of the copper pipe, but also isolate the moisture and oxygen in the air between the air inlet pipe 13 and the copper pipe, preventing corrosion from occurring. In addition, the copper plating layer surface can easily spread the melted workpiece between the air inlet pipe 13 and the copper pipe of the air conditioner evaporator, so that the melted base material can more uniformly form a filling between the air inlet pipe 13 and the air conditioner evaporator, thereby further enhancing the connection strength and welding quality between the air inlet pipe 13 and the copper pipe of the air conditioner evaporator.

[0053] The copper plating method for the first elbow pipe 2, the second elbow pipe 3 and the air inlet pipe 13 can be electroplating copper, chemical plating copper, hot-dip plating copper or mechanical plating copper. Specifically, the actual production needs are not specifically limited, and the present application preferably uses electroplating copper. The steel pipe is used as a cathode, and the copper metal is used as an anode. They are put into an electrolyte containing copper ions together. After power is turned on, the copper of the anode is dissolved into copper ions. The copper ions in the solution get electrons on the surface of the steel pipe of the cathode, are reduced into metal copper and are deposited.

[0054] As a preferred embodiment, the step S2 further includes cleaning the cylinder body 1 to remove oil stains and impurities on the inner and outer surfaces.

[0055] The present application cleans the inside and outside of the cylinder body 1 after forming the structure of the cylinder body 1, thereby effectively removing foreign matters in the cylinder body 1, avoiding damage to the subsequent liquid accumulator, avoiding the foreign matters from the liquid accumulator into the compressor to cause the compressor to be stuck, and thereby improving the operation safety performance of the entire liquid accumulator.

[0056] As a preferred embodiment, in the S5, the grooving machine with the middle plate 4 grooves the outer circumferential surface of the cylinder body 1. The grooving machine grooves the corresponding positions of the outer circumferential surface of the cylinder body 1 close to the side with the first opening and the second opening. The grooving wheel is pressed inward along the radial direction relative to the outer circumferential surface of the cylinder body 1 to form the first groove and the second groove with a preset distance. The first groove and the second groove form the first grooving position 6 on the outer circumferential surface of the cylinder body 1, and the middle plate 4 is installed in the first grooving position 6.

[0057] Similarly, in the step S6, the grooving machine with the filter screen 5 grooves the outer circumferential surface of the cylinder body 1. The grooving wheel is pressed inward along the radial direction relative to the outer circumferential surface of the cylinder body 1 to form the third groove and the fourth groove with a preset distance. Figure 4As shown, the second groove 7 is formed between the third groove and the fourth groove on the outer circumferential surface of the cylinder 1, and the filter screen 5 is installed in the second groove 7.

[0058] As shown in Figure 5 and Figure 6 As shown, the open side of the cylinder 1 is formed by spinning to have a third opening 9 and a convex portion 8 protruding axially outward, the cylinder is formed by spinning the convex portion 8 by a spinning machine, the spinning machine is equipped with a spindle positioning function, which can determine the position of the spindle clamp and the bent pipe, and ensure that the bent pipe that has been fixed can be smoothly put into the spindle clamp; then, the gas inlet pipe 13 with the third copper plating layer 12 is connected with the third opening 9 by resistance welding, wherein the gas inlet pipe does not have the third copper plating layer 12 connected in the third opening, and one end of the third copper plating layer is outwardly arranged for connection with the copper pipe of the air conditioner evaporator.

[0059] In addition, it also includes the step S9, the appearance detection and the pressure maintaining detection are carried out to the above-mentioned assembled solderless double pipe liquid reservoir, and the packaging is carried out after the detection is qualified.

[0060] The places not mentioned in the present application can be realized by using or referring to the existing technology.

[0061] Each embodiment in the present specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly explains the difference from other embodiments.

[0062] The above only describes the embodiments of the present application and is not used to limit the present application. The present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for manufacturing a solderless dual-tube liquid reservoir, characterized in that, The specific steps include: S1: a circular steel sheet is stretched by a stretching machine to form a cylindrical barrel with one side sealed and the other side open along the axial direction; S2: a first opening and a second opening are formed on the sealed side of the barrel in the radial direction; S3: a first elbow pipe with a first copper plating layer is resistance-welded with the first opening; S4: a second elbow pipe with a second copper plating layer is resistance-welded with the second opening; S5: a groove carving machine with a middle plate carves grooves on the outer circumferential surface of the barrel to form a first groove position on the barrel, and the middle plate is installed in the first groove position; S6: a groove carving machine with a filter screen carves grooves on the outer circumferential surface of the barrel to form a second groove position on the barrel, and the filter screen is installed in the second groove position; S7: the open side of the barrel is spin-formed to form a protruding part with a third opening protruding outward along the axial direction; S8: an air inlet pipe with a third copper plating layer is connected with the third opening by resistance welding.

2. A method of manufacturing a solderless dual-tube reservoir as claimed in claim 1, wherein, In the step S3, before assembly, the first elbow pipe is formed by turning and cold upsetting, and one end of the first elbow pipe is bent inward by 90°, so that the first elbow pipe forms a first straight section and a first bent section along the axial direction; the first bent section is processed by copper plating to form a first copper plating layer.

3. A method of manufacturing a solderless dual-tube reservoir as claimed in claim 2, wherein, In the step S3, one end of the first straight section is resistance-welded with the first opening of the barrel; the first curved section extends out of the first opening and extends along the radial direction of the barrel.

4. A method of manufacturing a solderless dual-tube reservoir as claimed in claim 2, wherein, The first copper plating layer is at least partially solidified on the inner and outer surfaces of the end of the outward end of the first bent section along the extension direction of the first bent section.

5. The method for manufacturing a solderless dual-tube liquid reservoir as described in claim 1, characterized in that, In the step S4, before assembly, the second elbow pipe is formed by turning and cold upsetting, and one end of the second elbow pipe is bent inward by 90°, so that the second elbow pipe forms a second straight section and a second bent section along the axial direction; the second bent section is processed by copper plating to form a second copper plating layer.

6. A method of manufacturing a solderless dual-tube reservoir as claimed in claim 5, wherein, In the step S4, one end of the second straight section is resistance-welded with the second opening of the barrel; the second curved section extends out of the second opening and extends along the radial direction of the barrel.

7. A method of making a solderless dual-tube reservoir as defined in claim 5, wherein, The second copper plating layer is at least partially solidified on the inner and outer surfaces of the end of the outward end of the second bent section along the extension direction of the second bent section.

8. The method of claim 1, wherein the solderless dual-tube reservoir is manufactured by, In the step S8, before assembly, the air inlet pipe is formed by turning or cold upsetting, and then processed by copper plating, so that the outward end of the air inlet pipe has a third copper plating layer.

9. A method of manufacturing a solderless dual-tube reservoir as claimed in claim 8, wherein, The third copper plating layer is at least partially solidified on the inner and outer surfaces of the end of the outward end of the air inlet pipe along the axial direction of the air inlet pipe.

10. The method of claim 1, wherein the solderless dual-tube reservoir is manufactured by, Before the step S2, the barrel is cleaned to remove oil stains and impurities on the inner and outer surfaces.

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