Refrigeration system vacuumizing method, device and assembly intelligent manufacturing line

Abstract

The application relates to the technical field of refrigerators, in particular to a refrigeration system vacuumizing method and device and an assembly intelligent manufacturing production line. The refrigeration system vacuumizing method comprises the following steps: acquiring a vacuum pressure value, a pressure drop slope and a water molecule concentration in a gas extraction channel in real time; a multivariable PID closed-loop feedback control model is constructed, the vacuum pressure value, the pressure drop slope and the water molecule concentration are taken as feedback input quantities, and a gas extraction rate is adjusted in real time through a PID algorithm. According to the refrigeration system vacuumizing method, three key working condition parameters, i.e. the vacuum pressure value, the pressure drop slope and the water molecule concentration in the gas extraction channel, can be captured in real time, the parameters are taken as feedback input quantities through the construction of the multivariable PID closed-loop feedback control model, the gas extraction rate is adjusted in real time through the PID algorithm, accurate and self-adaptive regulation and control of the vacuumizing process are realized, and the problems of incomplete vacuumizing and excessive water residue caused by the existing blind extraction process can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of refrigerator technology, and in particular to a method, apparatus and intelligent manufacturing production line for vacuuming a refrigeration system. Background Technology

[0002] In the manufacturing and assembly of traditional refrigerator refrigeration systems, the integrity, internal cleanliness, and dryness of the refrigeration circuit are the core key factors determining the thermodynamic efficiency, operational stability, and service life of the equipment. After the piping welding and overall assembly of the refrigerator refrigeration system are completed, non-condensable gases (such as air) and condensable gases (mainly liquid water and water vapor) inevitably remain inside. These residues can seriously affect the refrigerant heat exchange efficiency, increase the compressor's operating load, and even cause system failures. Therefore, it is essential to thoroughly remove these residues through a rigorous vacuuming and dehydration process to ensure that the system meets its design operating standards.

[0003] Currently, refrigerator refrigeration system production lines commonly employ a time-based static open-loop control strategy (industry-widely known as "blind vacuuming") to perform vacuuming operations. This process controls the vacuum pump unit's operation by pre-setting a fixed vacuuming duration, failing to adaptively adjust the pumping rate based on actual residual conditions. It represents a crude control mode without feedback or calibration. In high-humidity production environments, residual liquid water inside the system can locally freeze due to intense heat absorption during a sudden pressure drop caused by vacuuming. The sublimation of frozen water is extremely slow; even if the vacuum gauge indicates the pressure has reached the target, ice crystals may still be hidden deep within the pipes. After refrigerant is charged and the system is operational, this water melts and refreezes at the lowest temperature capillary tube outlet, completely clogging the refrigeration system. This can lead to refrigeration failure, compressor damage, and other malfunctions, reducing product reliability and increasing after-sales costs. Summary of the Invention

[0004] To address the technical problem that blind vacuuming processes in refrigerator refrigeration system assembly lines can easily cause icing in the internal pipes of the refrigeration system, this application provides a vacuuming method, device, and intelligent manufacturing assembly line for a refrigeration system.

[0005] The first aspect of this application provides a method for evacuating a refrigeration system, comprising:

[0006] Real-time acquisition of vacuum pressure, pressure drop slope, and water molecule concentration within the air extraction channel;

[0007] A multivariable PID closed-loop feedback control model is constructed, using the vacuum pressure value, pressure drop slope and water molecule concentration as feedback inputs, and the opening of the regulating valve in the air extraction channel is adjusted in real time through the PID algorithm.

[0008] When the water molecule concentration is greater than the first preset value and the pressure drop slope is greater than or equal to the second preset value, the control valve is fully opened to create a vacuum at the maximum pumping rate.

[0009] When the water molecule concentration is greater than the first preset value and the pressure drop slope is less than the second preset value, the pressure drop slope is the controlled variable and the second preset value is the PID control target value. Combined with the real-time feedback of water molecule concentration, the PID algorithm reduces the opening of the regulating valve and reduces the pumping rate, so that the pressure drop slope is stabilized within the range of greater than or equal to the second preset value.

[0010] When the water molecule concentration is less than or equal to the first preset value, the control valve maintains its current opening until the vacuum pressure reaches the first preset pressure value.

[0011] By employing the aforementioned vacuuming method for the refrigeration system, three key operating parameters—vacuum pressure, pressure drop slope, and water molecule concentration—can be captured in real time within the vacuuming channel. By constructing a multivariable PID closed-loop feedback control model, these parameters are used as feedback inputs. The PID algorithm is then used to adjust the vacuuming rate in real time, achieving precise and adaptive control of the vacuuming process. This effectively improves the problems of incomplete vacuuming and excessive moisture residue caused by existing "blind vacuuming" processes, significantly reduces the probability of ice blockage, and enhances the operational stability and service life of the refrigerator's refrigeration system.

[0012] In some embodiments, reducing the valve opening and decreasing the pumping rate using a PID algorithm includes:

[0013] The PID algorithm is used to reduce the opening of the regulating valve in real time according to the deviation of the pressure drop slope.

[0014] Using the pressure drop slope deviation as the basis for PID algorithm control, it can capture the deviation between the pressure drop slope and the preset value in real time. The algorithm accurately calculates and controls the valve opening, avoiding lag or excessive deviation in valve opening adjustment. This ensures the pressure drop slope quickly approaches and reaches the second preset value, thus guaranteeing effective water discharge. Simultaneously, real-time deviation-based control allows the valve opening adjustment to better match dynamic changes in operating conditions, reducing pipeline pressure fluctuations caused by improper opening adjustments and better protecting the refrigeration pipeline and vacuum pump unit.

[0015] In some embodiments, reducing the valve opening and decreasing the pumping rate using a PID algorithm includes:

[0016] Using a second preset value as the target value for PID control, the deviation between the current pressure drop slope and the second preset value is obtained; the opening of the regulating valve is reduced in real time through the PID algorithm, and the reduction in the opening of the regulating valve is linearly related to the deviation value.

[0017] Based on the second preset value, the control target of the pressure drop slope can be clearly defined, ensuring the accuracy of the control direction. The reduction in opening degree is linearly related to the deviation value, which can realize the synchronous adaptation of deviation change and opening degree adjustment. The larger the deviation, the more reasonable the corresponding adjustment range, avoiding the problems of over-adjustment or under-adjustment. This makes the pressure drop slope more smoothly approach the second preset value, thereby better ensuring the water discharge effect, reducing system water residue, and further reducing the probability of ice blockage.

[0018] In some embodiments, reducing the valve opening and decreasing the pumping rate using a PID algorithm further includes:

[0019] The opening of the regulating valve is reduced in real time by the PID algorithm until the infrared moisture sensor detects that the attenuation value of the absorption intensity reaches the preset attenuation value. It is then determined that the liquid water has been gently extracted in gaseous form, and the risk of ice blockage is eliminated.

[0020] After the risk of ice blockage is eliminated, the water molecule concentration in the air extraction channel is monitored in real time.

[0021] If the water molecule concentration is greater than the first preset value, the control valve is kept at its current opening until the pressure drop slope stabilizes within a preset range greater than or equal to the second preset value, at which point the control valve is restored to its maximum opening.

[0022] If the water molecule concentration is less than or equal to the first preset value, the control valve will maintain its current opening and continue pumping air.

[0023] By monitoring the attenuation value of absorption intensity using an infrared moisture sensor, it is possible to accurately determine whether liquid water is being gently extracted in gaseous form, thus identifying the point at which the risk of ice blockage is eliminated. This avoids blindly adjusting the valve opening due to incomplete ice blockage, which could lead to blockage of the refrigeration system pipelines and interruption of vacuuming. At the same time, the "gentle extraction" control method can prevent liquid water from freezing due to excessively fast extraction speed, further reducing the risk of ice blockage.

[0024] In some embodiments, during the process of reducing the opening of the regulating valve and decreasing the pumping rate by using a PID algorithm, the minimum value of the adjustment range of the opening of the regulating valve is 25% of the maximum opening of the regulating valve.

[0025] Setting the minimum opening of the regulating valve to 25% prevents excessive valve closure, which could lead to a low pumping rate and significantly reduce vacuuming efficiency and moisture discharge. This ensures that while controlling the pressure drop rate, a certain pumping capacity is maintained, guaranteeing effective moisture removal, reducing system moisture residue, and further lowering the probability of ice blockage. Simultaneously, avoiding excessively low valve opening prevents abnormal pressure increases in the pumping channel, reducing the load impact on the refrigeration system piping and vacuum pump, protecting equipment from damage, and extending its service life.

[0026] Therefore, by properly adapting the air extraction conditions of the refrigerator's refrigeration system, it can quickly respond to deviation changes through the proportional coefficient, eliminate steady-state errors through the integral coefficient, and predict deviation change trends through the differential coefficient, thereby achieving stable and precise adjustment of the valve opening. It can also simplify the debugging process of the control parameters and reduce debugging costs in the production process.

[0027] In some embodiments, it also includes:

[0028] When the water molecule concentration is less than or equal to the first preset value and the vacuum pressure reaches the first preset pressure value, the vacuuming is completed, and the vacuum pump and / or regulating valve are turned off.

[0029] Using water molecule concentration and vacuum pressure as dual parameters to determine whether vacuuming is complete, it can accurately determine whether the residual moisture and vacuum level inside the system meet the preset requirements. This avoids problems such as incomplete vacuuming or over-vacuuming caused by judging by a single parameter. It ensures that the cleanliness and dryness inside the refrigeration system meet the design standards, reduces residual moisture, further reduces the probability of ice blockage, and avoids energy waste caused by over-vacuuming, thus improving evacuation efficiency.

[0030] In some embodiments, it also includes:

[0031] Connect the vacuuming device to the piping of the refrigerator's refrigeration system, obtain the sealing pressure in the vacuum channel, and determine whether there is a leak. If there is no leak, control the regulating valve to be fully opened and enter the vacuuming process.

[0032] By adding sealing pressure detection and leakage judgment steps before the vacuuming process is started, the vacuuming control process has been further improved, enhancing the safety, reliability, and rationality of the control method, and laying the foundation for the smooth implementation of subsequent vacuuming processes.

[0033] In some embodiments, it also includes:

[0034] After docking, the vacuum pump of the vacuum pumping device is started, and the pressure in the pumping channel is pumped to the second preset pressure value.

[0035] Pressure holding;

[0036] Obtain the vacuum pressure decay value during the pressure holding period, and determine whether there is a leak based on the vacuum pressure decay value and the preset decay value.

[0037] By comparing the vacuum pressure decay value with a preset decay value to determine the leakage situation, the degree of leakage can be quantitatively assessed, avoiding misjudgments caused by subjective judgment. This approach can accurately identify subtle leaks and other difficult-to-detect problems, while avoiding misinterpreting normal pressure fluctuations as leaks, thus improving the scientific rigor and precision of leak detection. Furthermore, this refined leak detection process allows for precise early detection of potential leaks during the vacuuming process, preventing the need for subsequent vacuuming operations in the event of a leak. This avoids problems such as low vacuuming efficiency, inability to reach the preset vacuum pressure value, and difficulty in removing residual moisture, reducing energy waste and unnecessary equipment wear.

[0038] In some embodiments, the real-time acquisition of the vacuum pressure value, pressure drop slope, and water molecule concentration within the pumping channel includes:

[0039] A vacuum pressure sensor is used to collect pressure data in the air extraction channel, including the vacuum pressure value, and the pressure drop slope is obtained from the pressure data. An infrared moisture sensor is used to collect moisture absorption spectrum data in the air extraction channel, and the water molecule concentration is obtained from the moisture absorption spectrum data combined with Beer-Lambert's law.

[0040] A vacuum pressure sensor is used to collect pressure data, which can capture the vacuum pressure value in the pumping channel in real time and accurately. By processing the continuously collected pressure data, the pressure drop slope can be obtained, which can truly reflect the dynamic change trend of pressure during the pumping process, avoiding the errors caused by manual collection or indirect calculation, and ensuring the accuracy of pressure-related parameters. An infrared moisture sensor is used to collect moisture absorption spectrum data, and the water molecule concentration is calculated by combining it with the Beer-Lambert law. This enables real-time, non-contact, and accurate detection of water molecule concentration. Compared with traditional detection methods, it can effectively avoid interference with the pumping process during the detection process, and improve the sensitivity and accuracy of moisture detection. It can accurately capture trace amounts of residual moisture in the system, providing a scientific basis for the subsequent control of the pumping rate.

[0041] A second aspect of this application provides a vacuum pumping device for a refrigeration system, used to perform the vacuum pumping method as described in any of the preceding claims, comprising:

[0042] vacuum pump,

[0043] The self-positioning insertion mechanism is connected to the vacuum pump via a connecting pipe and is used for a sealed connection with the piping of the refrigeration system.

[0044] An infrared moisture sensor is mounted on the connecting tube and is used to detect the moisture absorption spectrum data inside the connecting tube.

[0045] A vacuum pressure sensor is installed on the connecting pipe to detect pressure data inside the connecting pipe;

[0046] An adjusting valve is installed inside the connecting pipe to adjust the effective cross-sectional area of ​​the air extraction channel inside the connecting pipe.

[0047] The controller is electrically connected between the infrared moisture sensor, the vacuum pressure sensor, and the regulating valve. The controller is configured to construct a multivariable PID closed-loop feedback control model and use moisture absorption spectrum data and pressure data as feedback inputs to adjust the opening degree of the regulating valve and / or the operating frequency of the vacuum pump in real time through a PID algorithm.

[0048] The coordinated operation of all components in the entire device can not only effectively improve the crude defects of existing "blind pumping" devices, reduce residual moisture in the system and lower the probability of ice blockage, but also improve vacuuming efficiency, reduce energy waste, protect refrigeration pipes and equipment themselves, and extend the service life of the equipment.

[0049] In some embodiments, the self-positioning insertion mechanism includes a three-dimensional moving unit, a positioning vision camera, and a self-positioning quick connector. The positioning vision camera and the self-positioning quick connector are disposed at the end of the three-dimensional moving unit, and the positioning vision camera is configured to acquire the three-dimensional spatial position of the pipe connection port of the refrigeration system. The self-positioning quick connector is used for sealing and docking with the pipe of the refrigeration system.

[0050] The three components work together to enable the self-positioning insertion mechanism to achieve an integrated function of "precise positioning, rapid docking, and reliable sealing". This reduces manual intervention, lowers the cost and error of manual operation, and improves the consistency and reliability of docking. It avoids problems such as leakage and low air extraction efficiency caused by docking deviation, and further reduces the residual moisture in the system and the probability of ice blockage.

[0051] In some embodiments, the controller is configured to: calculate the pressure drop slope based on the pressure data in the pumping channel collected by the vacuum pressure sensor, and obtain the water molecule concentration based on the moisture absorption spectrum data in the pumping channel collected by the infrared moisture sensor combined with the Beer-Lambert law.

[0052] Further improve the adaptability of the pumping rate control, better reduce residual moisture in the system, reduce the probability of ice blockage, protect refrigeration pipelines and equipment, and improve vacuuming efficiency and product consistency.

[0053] A third aspect of this application provides a refrigeration system assembly line, including a conveying device and, sequentially arranged along the conveying direction of the conveying device, a raw material storage unit, a loading unit, a refrigeration system assembly unit, a welding and maintenance unit, a refrigerant injection and sealing inspection unit, a unloading unit, and a finished product storage unit. The raw material storage unit is used to store compressors and evaporators to be assembled. The loading unit is used to transport the compressors and evaporators to be assembled to the refrigeration system assembly unit. The refrigeration system assembly unit is used to assemble the compressors and evaporators onto a refrigerator chassis. The welding and maintenance unit is used to complete the piping, welding, and welding quality inspection of the compressors and evaporators. The refrigerant injection and sealing inspection unit includes a vacuuming device, an automatic refrigerant injection device, a sealing device, and a leak detection device as described in any of the above-mentioned embodiments. The unloading unit is used to transport leak-tested finished products to the finished product storage unit for storage.

[0054] This production line abandons the long, rigid, sequential model of existing production lines, which follows a "raw material loading - cabinet foaming - final assembly - testing and feedback - finished product unloading" path. Instead, it treats refrigeration system assembly as an independent core process, setting up functional units sequentially along the conveyor direction. This shortens the flow path of refrigeration system assembly and avoids fast-paced processes such as refrigeration system pipe welding from being on the same main line as slow-paced processes such as cabinet polyurethane foaming and inner liner assembly. This effectively breaks the bottleneck of mutual constraints between different pace processes and significantly improves the overall production balance rate.

[0055] In some embodiments, the refrigeration system assembly unit includes a compressor assembly robot and an evaporator assembly robot, which are arranged opposite each other on both sides of the conveying device to simultaneously assemble the compressor and the evaporator onto the refrigerator chassis.

[0056] By positioning two robots opposite each other on either side of the conveyor, the compressor and evaporator are assembled synchronously. This completely changes the traditional sequential assembly mode of "installing the compressor first, then the evaporator," significantly shortening the cycle time of the refrigeration system assembly unit. It makes the cycle time of the assembly process more compatible with that of processes such as material feeding, welding, and inspection, further breaking the bottleneck of mutual constraints between different process cycles and improving the overall production balance rate. Simultaneously, the opposite layout on both sides fully utilizes the space on both sides of the conveyor, avoiding mutual interference between robots during operation and ensuring the smoothness and stability of the assembly process. The automated operation of the robots enables continuous and efficient operation without human intervention, ensuring production continuity and avoiding production line stoppages caused by manual operation delays, further improving the overall operating efficiency of the production line.

[0057] In some embodiments, the compressor assembly robot includes a first robotic arm, an eccentric flange, a first gripping mechanism, and a tightening fastener. The eccentric flange is connected between the first robotic arm and the first gripping mechanism so that the first robotic arm and the first gripping mechanism are eccentrically positioned. The first gripping mechanism is used to grip the compressor. The tightening fastener is correspondingly inserted through the mounting hole of the compressor base, and the tightening fastener can partially penetrate into the locking hole of the refrigerator chassis under the action of external force and elastically abut against the hole wall of the locking hole.

[0058] The eccentric flange effectively avoids interference between the first robotic arm and components such as the evaporator assembly robot, conveying devices, or the refrigerator chassis. It fully utilizes the assembly space, ensuring smooth and synchronous operation of two opposing robots, preventing assembly stalls caused by spatial interference, guaranteeing the stability of the synchronous assembly cycle, and further mitigating constraints caused by differences in process cycle times. The expansion bolts enable rapid and secure locking of the compressor to the refrigerator chassis. Compared to traditional bolt locking, the expansion bolts can partially penetrate the locking holes in the refrigerator chassis under external force and elastically abut against the hole walls, eliminating the need for additional tightening. This significantly shortens the locking time, further optimizing the assembly cycle time and making the compressor assembly process more compatible with the evaporator assembly, subsequent welding and inspection processes, and improving the overall production balance.

[0059] In some embodiments, the expansion locking fastener includes an elastic expansion portion, a buffer pad, and a pressing portion arranged sequentially along the axial direction. The elastic expansion portion passes through the locking hole and elastically abuts against the hole wall of the locking hole. The buffer pad is disposed between the base of the compressor and the refrigerator chassis. The pressing portion is located above the mounting hole and elastically presses against the base of the compressor to fix the compressor to the refrigerator chassis.

[0060] The flexible abutment mechanism effectively compensates for minor coaxiality deviations between the locking hole and the mounting hole, preventing loosening due to hole misalignment. This ensures locking reliability and reduces gap errors in vibration transmission. The buffer pad, acting as an independent buffer layer, isolates the compressor base from the refrigerator's metal bottom plate. Its elastic deformation absorbs low-frequency vibration energy generated during compressor start-up, shutdown, and operation, further blocking vibration transmission paths. Structurally, this prevents the formation of "sound bridges," effectively suppressing mechanical resonance, reducing low-frequency structural noise, addressing a high-frequency complaint pain point in the home appliance industry, and improving the overall acoustic performance of the refrigerator and the user experience.

[0061] In some embodiments, a rework isolation unit is also included, which is used to receive products that fail the inspection by the sampling and sealing unit, repair them, and return them to the sampling and sealing unit.

[0062] The addition of the rework isolation unit enables standardized and intensive management of non-conforming products through "nearby reception - centralized rework - closed-loop re-inspection". This fundamentally solves the problems of logistics congestion and inefficient rework caused by the cross-regional transfer of non-conforming products, and achieves seamless integration of quality control and production process. Attached Figure Description

[0063] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0064] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0065] Figure 1 This is a schematic diagram of the intelligent manufacturing production line for assembling the refrigeration system described in the embodiments of this application;

[0066] Figure 2 This is a schematic diagram of the loading and unloading process described in the embodiments of this application;

[0067] Figure 3 This is a schematic diagram of the structure of the refrigeration system assembly unit described in the embodiments of this application;

[0068] Figure 4 This is a schematic diagram of the compressor assembly robot described in an embodiment of this application;

[0069] Figure 5 This is a schematic diagram of the structure of the first end effector in an embodiment of this application;

[0070] Figure 6 This is a force analysis diagram of the first gripping mechanism gripping the compressor in an embodiment of this application;

[0071] Figure 7 This is a schematic diagram of the structure of the expansion locking fastener described in the embodiments of this application;

[0072] Figure 8 This is a schematic diagram of the evaporator assembly robot described in an embodiment of this application;

[0073] Figure 9 This is a schematic diagram of the structure of the second gripping mechanism in an embodiment of this application;

[0074] Figure 10 This is a schematic diagram of the piping robot described in an embodiment of this application;

[0075] Figure 11This is a schematic diagram of the end clamp mechanism described in the embodiments of this application;

[0076] Figure 12 This is a schematic diagram of the structure of the high-frequency induction welding pipe robot described in the embodiments of this application;

[0077] Figure 13 This is a schematic diagram of the structure of the terminal high-frequency heating unit described in the embodiment of this application;

[0078] Figure 14 This is a schematic diagram of the welding and maintenance unit described in the embodiments of this application;

[0079] Figure 15 This is a schematic diagram of the structure of the injection and sealing inspection unit described in the embodiments of this application;

[0080] Figure 16 This is a schematic diagram of the vacuum pumping device described in the embodiments of this application;

[0081] Figure 17 This is a schematic diagram of the installation structure of the vacuum pump, infrared moisture sensor, vacuum pressure sensor and regulating valve described in the embodiments of this application;

[0082] Figure 18 This is a schematic diagram of the installation structure of the infrared moisture sensor, vacuum pressure sensor, and regulating valve described in the embodiments of this application;

[0083] Figure 19 This is a schematic diagram of the self-positioning insertion mechanism described in the embodiments of this application;

[0084] Figure 20 for Figure 19 A magnified view of point A in the middle;

[0085] Figure 21 This is a flowchart of the vacuuming method for the refrigeration system described in the embodiments of this application;

[0086] Figure 22 This is a schematic diagram of the vertical pump unit described in the embodiments of this application;

[0087] Figure 23 This is a schematic diagram of the refrigerant self-positioning mechanism described in the embodiments of this application;

[0088] Figure 24 This is a schematic diagram of the structure of the laser tail-sealing robot described in the embodiments of this application;

[0089] Figure 25 This is a schematic diagram of the structure of the laser welding unit described in the embodiments of this application;

[0090] Figure 26 This is a schematic diagram of the leak detection robot described in the embodiments of this application;

[0091] Figure 27 This is a schematic diagram of the leak detection unit described in an embodiment of this application.

[0092] Among them, 10. Conveying device;

[0093] 1. Raw material storage unit; 11. Raw material rack; 12. Stacking robot;

[0094] 2. Feeding unit; 21. Online robot;

[0095] 3. Refrigeration system assembly unit; 31. Compressor assembly robot; 311. First robotic arm; 312. Eccentric flange; 313. First gripping mechanism; 314. First cylinder; 315. First vision camera; 316. Torque sensor; 317. Expansion locking fastener; 3171. Central guide pin; 3172. Elastic expansion part; 3173. Buffer pad; 3174. Damping bushing; 3175. Limiting flange; 32. Evaporator assembly robot; 321. Second six-axis robotic arm; 322. Second gripping mechanism; 3221. Vacuum suction cup assembly; 3222. Electric gripper; 3223. Angle adjustment flange; 3224. 3D structured light camera;

[0096] 4. Welding and Repair Unit; 41. Piping Robot; 411. Six-Axis Collaborative Robotic Arm; 412. End-of-Line Pipe Clamping Mechanism; 4121. Pneumatic Gripper; 4122. 3D Industrial Camera; 4123. Second Cylinder; 42. High-Frequency Induction Welding Pipe Robot; 421. Multi-Axis Robotic Arm; 422. End-of-Line High-Frequency Heating Unit; 4221. Infrared Dual-Color Thermometer; 4222. High-Frequency Coaxial Transformer; 4223. 3D Structured Light Vision Camera; 4224. Heat Insulation Shield; 4225. Non-Contact Induction Coil; 43. Rework Isolation Unit; 431. Non-Destructive Testing Room; 432. Rework Robot;

[0097] 5. Refrigerant injection and sealing inspection unit; 51. Vacuum pump; 511. Vacuum pump; 512. Self-positioning insertion mechanism; 5121. X-axis travel mechanism; 5122. Z-axis travel mechanism; 5123. Positioning vision camera; 5124. Self-positioning quick-connect connector; 5125. Y-axis travel mechanism; 513. Connecting pipe; 514. Infrared moisture sensor; 515. Vacuum pressure sensor; 516. Regulating valve; 52. Automatic refrigerant injection device; 521. Electromagnetic flow meter; 522. Refrigerant delivery pipeline; 523. 524. Injection servo valve; 525. Refrigerant storage tank; 526. XYZ stroke mechanism assembly; 527. CCD camera; 53. Refrigerant connector; 54. Laser sealing robot; 55. Laser welding unit; 56. Laser welding head; 57. 2D industrial camera; 58. Fiber laser; 59. Welding robotic arm; 50. Leak detection robot; 51. Redundant degree-of-freedom robotic arm; 52. Leak detection unit; 53. Leak detection probe; 54. Hydrogen-nitrogen leak detector; 55. Industrial camera;

[0098] 6. Unloading unit; 61. Offline robot;

[0099] 7. Finished goods storage unit; 71. AGV transport vehicle; 72. Buffer rack;

[0100] 8. Central control unit. Detailed Implementation

[0101] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0102] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0103] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0104] To address the shortcomings of existing refrigerator assembly lines, such as rigid coupling of logistics leading to limited overall production balance and difficulties in returning defective products for repair, causing mainline congestion, this application provides a smart manufacturing production line for refrigeration system assembly. This line separates the refrigerator's refrigeration system from the assembly line, avoiding the sharing of fast-paced processes like refrigeration system piping welding with slow-paced processes like polyurethane foaming and inner liner assembly on the same main line. This effectively breaks the bottleneck of mutual constraints between different processes.

[0105] Specifically, such as Figure 1 As shown, the intelligent manufacturing production line for refrigeration system assembly provided in this application embodiment includes a conveying device 10 and a raw material storage unit 1, a feeding unit 2, a refrigeration system assembly unit 3, a welding and maintenance unit 4, a sampling and sealing inspection unit 5, a unloading unit 6, and a finished product storage unit 7 arranged sequentially along the conveying direction of the conveying device 10.

[0106] Among them, reference Figure 2 As shown, the raw material storage unit 1 includes raw material shelves 11, a stacking robot 12, an online robot 21, and an AGV (Automated Guided Vehicle) transport vehicle 71. The central control unit 8 receives the production plan issued by the MES (Manufacturing Execution System) and schedules the AGV transport vehicle 71 to transport the corresponding model of foamed and cured refrigerator chassis to the entrance of the conveyor device. The online robot 21 picks up the refrigerator chassis from the AGV transport vehicle 71 and transfers it to the pallet of the conveyor device 10. At this time, the RFID (Radio Frequency Identification) reader captures the digital ID of the refrigerator chassis and generates a unique digital file for each machine. At the same time, the AGV transport vehicle 71 receives the synchronous material BOM (Bill of Materials) list issued by the central control unit 8. Based on the built-in SLAM (Simultaneous Localization and Mapping) dynamic path planning and real-time obstacle avoidance algorithm, it automatically drives to the raw material shelf 11, transports the compressor with pre-installed expansion locking fasteners 317 to the compressor assembly station, and transports other raw material components (including evaporators) of the refrigeration system to the corresponding stations.

[0107] Reference Figure 3 As shown, the refrigeration system assembly unit 3 includes a compressor assembly robot 31 and an evaporator assembly robot 32. The compressor assembly robot 31 and the evaporator assembly robot 32 are arranged opposite each other on both sides of the conveying device 10, and are used to simultaneously assemble the compressor and the evaporator onto the refrigerator chassis.

[0108] By positioning two robots opposite each other on either side of the conveyor 10, the compressor and evaporator are assembled synchronously. This completely changes the traditional sequential assembly mode of "installing the compressor first, then the evaporator," significantly shortening the cycle time of the refrigeration system assembly unit 3. This makes the cycle time of the assembly process more compatible with the cycles of material feeding, welding, and inspection, further breaking the bottleneck of mutual constraints between different process cycles and improving the overall production balance rate. Simultaneously, the opposite layout on both sides fully utilizes the space on both sides of the conveyor, avoiding mutual interference between the robots during operation and ensuring the smoothness and stability of the assembly process. The automated operation of the robots enables continuous and efficient operation without human intervention, ensuring production continuity and avoiding production line stagnation caused by manual operation delays, further improving the overall operating efficiency of the production line.

[0109] like Figure 4 and Figure 5 As shown, the compressor assembly robot 31 includes a first robotic arm 311 and a first end effector. The first end effector includes an eccentric flange 312, a first gripping mechanism 313, and a tightening fastener 317. The eccentric flange 312 is connected between the first robotic arm 311 and the first gripping mechanism 313 so that the first robotic arm 311 and the first gripping mechanism 313 are eccentrically positioned. The first gripping mechanism 313 is used to grip the compressor. The tightening fastener 317 is correspondingly inserted into the mounting hole of the compressor base, and the tightening fastener 317 can partially penetrate into the locking hole of the refrigerator chassis under the action of external force, and the ice elastically abuts against the hole wall of the locking hole.

[0110] When assembling the compressor, the expansion locking fastener 317 is first installed into the mounting hole of the compressor base. The first robotic arm 311 drives the first gripping mechanism 313 to move and grip the compressor. Then, the compressor is moved to the installation position and the expansion locking fastener 317 is pressed down so that the lower end of the expansion locking fastener 317 extends into the locking hole of the refrigerator chassis, thereby fixing the compressor in place.

[0111] The eccentric flange 312 can effectively avoid interference between the first robotic arm 311 and components such as the evaporator assembly robot 32, the conveying device 10, or the refrigerator chassis, making full use of the assembly space, ensuring that the two robots set opposite each other can work smoothly and synchronously, avoiding assembly stagnation caused by spatial interference, ensuring the stability of the synchronous assembly cycle, and further alleviating the constraints caused by the difference in process cycle time.

[0112] Furthermore, the first robotic arm 311 is a six-axis robotic arm, capable of flexible posture adjustment within the confined space of the compressor compartment. The compressor assembly robot 31 also includes a first vision camera 315, a first cylinder 314, and a torque sensor 316. The eccentric flange 312 has an overall bent eccentric structure, with its upper end face coaxially and fixedly connected to the end of the first robotic arm 311. The flange body extends eccentrically towards the working side, forming a clearance space to circumvent the space constraints of the compressor compartment. The eccentric flange 312 is made of aluminum alloy, which is lightweight and reduces the load on the robotic arm while ensuring strength. The first cylinder 314 is fixedly installed on the lower end face of the eccentric flange 312, with the cylinder body rigidly connected to the end face of the eccentric flange 312. The piston rod extends downward in the vertical direction and is connected to the drive mechanism of the first gripping mechanism 313. The first gripping mechanism 313 is a three-grip manipulator that drives the mechanical grippers to open and close through the extension and retraction of the piston rod. The three-jaw manipulator is located directly below the first cylinder 314, with its body coaxial with the piston rod. Its gripping range is 50-120mm, and its gripping force is at least 200N. It is used to grip the compressor. Anti-slip rubber pads are provided on the inner side of the manipulator's grippers to prevent the compressor from sliding during gripping. A vision camera is fixedly mounted on the side of the eccentric flange 312, with its lens facing the assembly area. It has a resolution of 1920×1080 and acquires visual images of the compressor compartment to determine the compressor's installation position and the location of the tightening fastener 317. A torque sensor 316 is fixedly connected to the root of the three-jaw manipulator. This high-precision sensor is used to collect torque signals in real time during assembly, providing feedback for flexible assembly control. When the torque reaches a preset threshold, the pressing action stops, ensuring appropriate assembly force.

[0113] During compressor assembly, the compressor assembly robot 31 simultaneously activates the first robotic arm 311 to control the first gripping mechanism 313 to move to the compressor storage position. A vision camera captures visual images of the compressor to determine the gripping position. The first gripping mechanism 313 is a three-jaw robotic arm that grips the compressor. A torque sensor 316 collects torque signals in real time during the gripping process to prevent excessive gripping force from damaging the compressor. Subsequently, the first robotic arm 311 moves the compressor to the installation position in the compressor compartment. The vision camera captures visual images of the compressor compartment to determine the installation position of the expansion locking fastener 317. The first cylinder 314 drives the first gripping mechanism 313 to press down, aligning the locking hole on the refrigerator base with the expansion locking fastener 317, and performing a vertical pressing action. This completes the screwless expansion assembly in a very short time. The torque sensor 316 collects torque signals in real time during the assembly process. When the torque reaches a preset threshold, the pressing stops to ensure appropriate assembly force.

[0114] During assembly, the compressor actually comes into contact with the end effector, a three-jaw manipulator. Therefore, the force exerted on the compressor during gripping can be simplified as follows: Figure 6 As shown. All three robotic grippers are in contact with the compressor, so there are three contact points between the robotic arm and the compressor. The force on the compressor is mainly the normal force N generated by the robotic grippers in contact with that point. i and frictional force f i The compressor's own weight is G, and the angle between the robotic arm and the center line is θ.

[0115] The contact between the mechanical gripper and the compressor can be considered as a point contact with friction. The critical condition for the compressor to be stably held by the mechanical gripper without slipping off is that the weight of the compressor equals the vertical component of the normal force and friction force exerted by the mechanical gripper on the compressor.

[0116]

[0117] Let the minimum normal force be N. min Then it should satisfy:

[0118]

[0119] Because the mechanical gripper's point of application and force on the compressor are uniformly distributed about the centerline, the normal pressure N on the compressor at the three contact points is... i They are the same size.

[0120] In this situation, the minimum positive pressure exerted on the clamped compressor is:

[0121]

[0122] Frictional force at each contact point:

[0123]

[0124] In the formula:

[0125] M represents the mass of the compressor, in kg;

[0126] g is the acceleration due to gravity;

[0127] μ is the static friction coefficient between the compressor surface and the rubber part of the three-jaw manipulator;

[0128] f1, f2, and f3 represent the static friction forces generated between the three mechanical claws and the surface of the compressor.

[0129] To prevent damage to the compressor surface from the mechanical gripper, the invention selects the minimum critical pressure value F at which the compressor is destroyed by pressure. To ensure that the compressor is not damaged by the robotic arm during gripping and assembly, the following inequality holds:

[0130] F>N min

[0131] Meanwhile, to ensure that the compressor is stably held by the three-jaw manipulator without slipping when it grasps the compressor, the following inequality also applies:

[0132]

[0133] 3N in the above inequality min Mg represents the static friction force between the three grippers and the compressor when the three-jaw manipulator grasps the compressor, and Mg represents the compressor's own weight.

[0134] According to the above formula, when both of the above inequalities are true, the three-jaw manipulator can ensure that the compressor can be stably held by the manipulator during the grasping and picking process without slipping, and can also ensure that the compressor will not be damaged by the manipulator.

[0135] like Figure 7 As shown, the expansion locking fastener 317 includes a central guide pin 3171, an elastic expansion part 3172, a buffer pad 3173, and a pressing part arranged sequentially along the axial direction. The elastic expansion part 3172 passes through the locking hole and elastically abuts against the hole wall of the locking hole. The buffer pad 3173 is located between the compressor base and the refrigerator chassis. The pressing part is located on the upper side of the mounting hole and elastically presses against the compressor base to fix the compressor and the refrigerator chassis.

[0136] The center guide pin 3171 has an inverted conical structure, used to convert axial thrust into radial expansion force. The center guide pin 3171 is made of steel and has undergone surface quenching treatment, resulting in high hardness. During the pressing of the expansion locking fastener 317, the center guide pin 3171 first enters the locking hole, guiding and pre-positioning the expansion locking fastener 317. The main body of the elastic expansion part 3172 is a multi-lobed elastic expansion flap. Anti-slip tooth surfaces are provided on the inner side of the expansion flaps, with a tooth pitch of 2mm. A damping bushing 3174 mounting groove is provided at the root. The elastic expansion body is made of elastic modified plastic with high hardness. When compressed, the expansion body radially contracts; when reset, it radially expands, tightening and locking with the inner wall of the fastener through the micro-tooth meshing surface, resulting in high tightening force.

[0137] The buffer pad 3173 is located at the root of the elastic expansion part 3172 and wraps around the outside of the elastic expansion part 3172. It is injection molded from a special butyl rubber and polyurethane composite foam material with a high internal friction loss factor. Its damping factor can reach 0.3. It is used to absorb and dissipate the medium and high frequency mechanical vibration during the operation of the compressor, while reducing the joint space, which can effectively reduce the vibration transmission rate during the operation of the compressor.

[0138] The clamping part includes a damping bushing 3174 and a limiting flange 3175. The limiting flange 3175 is located at the end of the expansion locking fastener 317 away from the central guide pin 3171, and the outer diameter of the limiting flange 3175 is larger than the diameter of the compressor's mounting hole. It is used to clamp and bear the static weight of the compressor. The damping bushing 3174 is nested in the mounting groove and is located between the limiting flange 3175 and the elastic expansion part 3172. The damping bushing 3174 is made of EPDM (Ethylene Propylene Diene Monomer) microporous elastomer to form a flexible vibration isolation layer. Its thickness can further reduce the vibration transmission during compressor operation.

[0139] like Figure 8 As shown, the evaporator assembly robot 32 includes a second six-axis robotic arm 321 and a second gripping mechanism 322. The second gripping mechanism 322 at its end includes a vacuum suction cup assembly 3221, an electric gripper 3222, an angle adjustment flange 3223, and a 3D structured light camera 3224. The evaporator assembly robot 32 moves the second gripping mechanism 322 to the evaporator storage position via the second six-axis robotic arm 321. The 3D structured light camera 3224 first acquires three-dimensional point cloud data of the evaporator to determine the gripping position. Subsequently, the electric gripper 3222 grips the pipe joints of the evaporator, and the vacuum suction cup assembly 3221 adheres to the fin surface of the evaporator to prevent fin deformation during gripping. Next, the second six-axis robotic arm 321 moves the evaporator to the installation area of ​​the refrigerator chassis. The 3D structured light camera 3224 collects the three-dimensional point cloud data of the installation area and compares it with the preset installation position. The angle adjustment flange 3223 adjusts the installation posture of the evaporator according to the comparison result, with a rotation angle range of ±90° to adapt to the installation angle requirements of different refrigerator models. Finally, the coil of the evaporator is embedded into the designated polymer slot in the refrigerator chassis, with high installation accuracy.

[0140] After the compressor and evaporator are installed, the tray containing the semi-finished refrigeration circuit is transported to the welding and maintenance unit 4, such as... Figure 14 As shown, the welding and maintenance unit 4 includes a piping robot 41, a high-frequency induction welding robot 42, and a rework isolation unit 43.

[0141] like Figure 10 As shown, the piping robot 41 includes a six-axis collaborative robotic arm 411 and an end-effector clamping mechanism 412. Figure 11As shown, the end-cap clamp mechanism 412 includes a pneumatic gripper 4121, a 3D industrial camera 4122, and a second cylinder 4123. The piping robot 41, controlled by a six-axis collaborative robotic arm 411, moves the customized end-cap clamp mechanism 412 to the storage position for the copper return and exhaust pipes. The 3D industrial camera 4122 captures a three-dimensional image of the pipe to determine its gripping position. The pneumatic gripper 4121 grips the pipe to be installed; its arc-shaped gripper structure and inner silicone anti-slip pads can adapt to pipes of different diameters, preventing slippage during gripping. Then, the six-axis collaborative robotic arm 411 moves the pipe to the corresponding interface of the compressor. The 3D industrial camera 4122 captures a three-dimensional image of the compressor interface to determine its position, precisely inserting the end of the pipe into the corresponding interface of the compressor with low insertion depth error.

[0142] Then, the high-frequency induction welding robot 42 intervened, such as Figure 12 As shown, the high-frequency induction welding pipe robot 42 includes a multi-axis robotic arm 421 and an end-effector high-frequency heating unit 422. The multi-axis robotic arm 421 is a six-axis robotic arm. Figure 13 As shown, the end high-frequency heating unit 422 includes an infrared dual-color thermometer 4221, a high-frequency coaxial transformer 4222, a 3D structured light vision camera 4223, a heat insulation guide shroud 4224, and a non-contact induction coil 4225. The high-frequency induction welding robot 42 controls the high-frequency heating unit to move to the pipe joint through the multi-axis robotic arm 421. The 3D structured light vision camera 4223 collects the three-dimensional spatial pose of the pipe joint to determine the heating position. The non-contact induction coil 4225 is a U-shaped water-cooled copper coil with a high-frequency inverter alternating current inside. The high-frequency coaxial transformer 4222 converts the high-frequency current into an alternating magnetic field to perform penetrating eddy current heating on the pipe joint. The detection optical path of the infrared dual-color thermometer 4221 is aligned with the heating center of the non-contact induction coil 4225. The temperature measurement range is 200-1200℃, which is used to collect the temperature rise curve of the weld pool in real time and feed it back to the central control unit 8. The central control unit 8 adjusts the power of the high-frequency current according to the temperature rise curve to ensure that the heating temperature is controlled within the melting range of the annular brazing filler metal, thus realizing flameless induction brazing. A heat insulation shield 4224, made of aluminum silicate fiber, covers the non-working side of the non-contact induction coil 4225. Its thickness effectively blocks heat dissipation, preventing heat from spreading to the surrounding plastic inner liner and polyurethane foam layer, thus keeping the ambient temperature below 60℃. A water-cooling channel is installed inside the non-contact induction coil 4225, with cooling water used to prevent overheating.

[0143] During the welding process, the multi-axis robotic arm 421 of the high-frequency induction welding pipe robot 42 controls the end-effector high-frequency heating unit 422 to move to the pipe joint. The 3D structured light vision camera 4223 acquires the three-dimensional spatial pose of the pipe joint to determine the heating position. Then, a non-contact induction coil 4225 approaches the pipe joint to control the distance. The high-frequency coaxial transformer 4222 converts the high-frequency current into an alternating magnetic field to perform penetrating eddy current heating on the pipe joint. The infrared dual-color thermometer 4221 acquires the temperature rise curve of the weld pool in real time. When the temperature reaches the melting point of the brazing filler metal, the heating time is maintained for 3 seconds, and then the heating is stopped to complete the welding. This welding method has no open flame and no radiation heating, eliminating the problems of inner liner burn and inner wall oxidation. The thickness of the oxide layer on the inner wall of the welded copper pipe is much lower than that of traditional flame brazing, effectively avoiding the problem of oxide scale peeling off and clogging the capillary tube.

[0144] After welding and cooling, the refrigerator chassis passes through an ultrasonic non-destructive testing chamber 431. The chamber 431 contains ultrasonic probes distributed around the perimeter of the refrigerator chassis, emitting high-frequency sound waves towards all circumferential welds and receiving the reflected echoes. The central control unit 8 uses a deep learning algorithm to determine whether structural defects such as incomplete welding, lack of fusion, or micropores exist within the welds based on the attenuation image and phase changes of the echo amplitude, achieving high accuracy. If a defect is identified as non-compliant (NG), the system immediately records the abnormal status on an RFID tag. When the pallet reaches a junction, the rework robot 432 in the rework isolation unit 43 immediately grabs the pallet, which is then transported by a dedicated AGV transport vehicle 71 to the rework island for targeted processing. The rework island is equipped with dedicated high-frequency induction welding equipment and ultrasonic testing equipment, allowing for the re-welding and inspection of defective welds, thus shortening rework time.

[0145] The qualified products continue to flow into the sampling and sealing inspection unit 5 via the conveyor device, where, for example... Figure 15 As shown, the injection and sealing inspection unit 5 includes a vacuuming device 51, an automatic refrigerant injection device 52, a laser sealing robot 53, and a leak detection robot 54.

[0146] like Figures 16 to 20 As shown, the vacuum pumping device 51 includes a vacuum pump 511, a self-positioning insertion mechanism 512, an infrared moisture sensor 514, a vacuum pressure sensor 515, a regulating valve 516, and a controller, wherein the controller is integrated in the central control unit 8.

[0147] like Figure 16As shown, multiple vacuum pumps 511 are configured to form a vacuum pump group 511. The vacuum pumps 511 are rotary vane vacuum pumps with high pumping speed, which can quickly reduce the pressure in the refrigeration system pipeline to a low vacuum state. The vacuum pumps 511 are connected to the self-positioning insertion mechanism 512 through the connecting pipe 513. The high-precision infrared moisture sensor 514 is installed in the connecting pipe 513 to collect the moisture absorption spectrum in the pipeline in real time. The controller quantitatively monitors the absolute water molecule concentration in the pipeline based on the moisture absorption spectrum and the Beer-Lambert law. When the water molecule concentration ρ is lower than the first preset value, the pipeline is considered to have reached a dry state.

[0148] The vacuum pressure sensor 515 has a wide measurement range and high accuracy. It is used to collect dynamic pressure changes in pipelines in real time. The controller can calculate the pressure drop slope based on the collected dynamic pressure changes.

[0149] The regulating valve 516 is a servo proportional regulating valve. The opening adjustment range of the regulating valve 516 is 0 to 100%. When the opening of the regulating valve 516 is 0, the regulating valve 516 is completely closed and the effective cross-sectional area of ​​the air extraction channel is 0. When the opening of the regulating valve 516 is 100%, the regulating valve 516 is fully open, the effective cross-sectional area of ​​the air extraction channel is at its maximum, and the air extraction rate is at its maximum.

[0150] The regulating valve 516 is connected in series in the pipeline upstream of the vacuum pump 511. The controller is electrically connected between the infrared moisture sensor 514, the vacuum pressure sensor 515 and the regulating valve 516. The controller is configured to construct a multivariable PID (Proportional-Integral-Derivative) closed-loop feedback control model, and uses moisture absorption spectrum data and pressure data as feedback inputs. The controller controls the opening degree of the regulating valve 516 and / or the operating frequency of the vacuum pump 511 in real time through the PID algorithm, thereby adjusting the pumping rate in real time.

[0151] In practice, the controller first calculates the water spectral data and pressure data to obtain the water molecule concentration and pressure drop slope. Based on the water molecule concentration and pressure drop slope, it judges whether there is a risk of ice blockage in the pipeline of the refrigeration system. Then, based on the judgment result, it adjusts the opening of the regulating valve 516 in real time, thereby adjusting the air extraction rate in real time.

[0152] like Figure 19 and Figure 20As shown, the self-positioning insertion mechanism 512 includes a three-dimensional moving unit, a positioning vision camera 5123, and a self-positioning quick connector 5124. The positioning vision camera 5123 and the self-positioning quick connector 5124 are disposed at the end of the three-dimensional moving unit. The positioning vision camera 5123 is configured to acquire the three-dimensional spatial position of the pipe connection port of the refrigeration system, and the self-positioning quick connector 5124 is used for sealing and docking with the pipe of the refrigeration system.

[0153] In a specific implementation, the three-dimensional moving unit includes an X-axis travel mechanism 5121, a Y-axis travel mechanism 5125, and a Z-axis travel mechanism 5122. The travel of the X-axis travel mechanism 5121, the Y-axis travel mechanism 5125, and the Z-axis travel mechanism 5122 cooperates with each other to drive the self-centering quick connector to move precisely in three-dimensional space.

[0154] The positioning vision camera 5123 has high resolution and is linked with the self-positioning quick connector 5124 at the end of the Y-axis travel mechanism 5125. It is used to accurately acquire the three-dimensional spatial pose of the refrigeration system pipe port and guide the self-centering quick connector to complete the fully automated sealing docking. The self-centering quick connector has high sealing pressure to ensure no leakage during the docking process.

[0155] After docking, vacuum pump 511 starts and begins vacuuming. Vacuum pressure sensor 515 collects pressure changes in the pumping channel in real time, and infrared moisture sensor 514 collects moisture absorption spectrum in the pumping channel in real time. Central control unit 8 executes anti-icing depth vacuuming algorithm based on pressure drop slope and moisture concentration. When the pressure drop slope is too small, it indicates that liquid water may be freezing in the pumping channel. Central control unit 8 will control regulating valve 516 to reduce the effective cross-sectional area of ​​the pumping channel and reduce the pumping rate to prevent liquid water from freezing suddenly. When the moisture concentration detected by infrared moisture sensor 514 is lower than the first preset value, the pumping channel is considered to be in a dry state.

[0156] Furthermore, during the evacuation process of the refrigeration system piping, the following method is used to achieve vacuum control:

[0157] In specific implementation, such as Figure 21 As shown, the vacuuming methods for the refrigeration system include:

[0158] S1, real-time acquisition of vacuum pressure value, pressure drop slope and water molecule concentration in the air extraction channel;

[0159] S2. Construct a multivariable PID closed-loop feedback control model, using vacuum pressure, pressure drop slope and water molecule concentration as feedback inputs. Adjust the pumping speed in real time through the PID algorithm, specifically by controlling the opening of the regulating valve 516.

[0160] Furthermore, step S2 specifically includes:

[0161] S21, when the water molecule concentration ρ is greater than the first preset value and the pressure drop slope K is greater than or equal to the second preset value, the regulating valve 516 is fully opened to perform vacuuming at the maximum pumping rate; in some embodiments of this application, the first preset value is 10ppm and the second preset value is 0.1Pa / s.

[0162] S22, when the water molecule concentration ρ is greater than the first preset value and the pressure drop slope K is less than the second preset value, the pressure drop slope K is used as the controlled variable and the second preset value is the target value of PID control. Combined with the real-time feedback of the water molecule concentration ρ, the opening of the regulating valve 516 is reduced and the pumping speed is reduced through the PID algorithm, so that the pressure drop slope K is stabilized within the preset range greater than or equal to the second preset value.

[0163] Understandably, when the water molecule concentration ρ is greater than the first preset value and the pressure drop slope K is less than the second preset value, it is determined that there is a tendency for liquid water to freeze in the pipeline. The PID algorithm is then activated to reduce the opening of the regulating valve 516, thereby reducing the pumping rate and preventing the liquid water from freezing due to a sudden pressure drop. This artificially slows down the pressure drop slope K. As the opening of the regulating valve 516 is reduced, the pressure drop slope decreases accordingly. After the regulating valve opening is adjusted, the pressure drop slope K gradually recovers as the pumping process continues until it reaches the second preset value. At this point, the regulating valve 516 is controlled to return to its maximum opening to continue pumping.

[0164] S23, when the water molecule concentration ρ is less than or equal to the first preset value and K is greater than or equal to the second preset value, it is determined that the water content in the pipeline meets the standard, and the regulating valve 516 is controlled to maintain the current opening until the vacuum pressure value reaches the first preset pressure value;

[0165] S24, when the water molecule concentration ρ is less than or equal to the first preset value and K is less than the second preset value, it is determined that the pipeline is close to the ultimate vacuum degree, and the regulating valve 516 is controlled to maintain the current opening until the vacuum pressure value reaches the first preset pressure value.

[0166] Furthermore, in some embodiments of this application, the step S22 of reducing the opening of the regulating valve 516 and reducing the pumping rate by using a PID algorithm specifically includes: reducing the opening of the regulating valve 516 in real time according to the pressure drop slope deviation using a PID algorithm.

[0167] In specific implementation, the second preset value is used as the target value for PID control, and the deviation value between the current pressure drop slope K and the second preset value is obtained; the opening of the regulating valve 516 is reduced in real time through the PID algorithm, and the reduction of the opening of the regulating valve 516 is linearly related to the deviation value.

[0168] The adjustment direction and pattern of the PID algorithm can be understood as follows:

[0169] Using the second preset value as the control target value, and the current measured pressure drop slope K=d P / d t As a feedback quantity, if the absolute value of K is much less than 0.1 Pa / s (pressure reduction is too slow): slowly increase the opening of regulating valve 516 to increase the pumping speed, so that the absolute value of K approaches 0.1 Pa / s. If the absolute value of K is greater than 0.1 Pa / s (pressure reduction is too fast): decrease the opening of regulating valve to reduce the pumping speed, forcibly pulling the absolute value of K back to close to 0.1 Pa / s.

[0170] Final steady state: The opening of regulating valve 516 automatically stabilizes at a relatively small value, so that the system naturally maintains an absolute value of K of approximately 0.1 Pa / s.

[0171] Furthermore, reducing the opening of regulating valve 516 and decreasing the pumping rate through the PID algorithm also includes:

[0172] The opening of the regulating valve 516 is reduced in real time by the PID algorithm until the infrared moisture sensor 514 detects that the attenuation value of the absorption intensity reaches the preset attenuation value, and it is determined that the liquid water has been gently extracted in gaseous form, and the risk of ice blockage is eliminated.

[0173] After the risk of ice blockage is eliminated, the water molecule concentration ρ in the air extraction channel is obtained in real time.

[0174] If the water molecule concentration ρ is greater than the first preset value, control valve 516 maintains the current opening until the pressure drop slope K stabilizes within a preset range greater than or equal to the second preset value, then control valve 516 restores the maximum opening.

[0175] If the water molecule concentration ρ is less than or equal to the first preset value, control valve 516 to maintain the current opening and continue pumping air.

[0176] In practice, at this stage, the infrared moisture sensor 514 monitors the moisture absorption intensity in real time, and the controller continuously receives the absorption intensity signal. When the detected absorption intensity attenuation value reaches 50% (preset attenuation value), it is determined that the liquid water in the pipeline of the refrigeration system has been completely and gently extracted in gaseous form, and the risk of ice blockage is eliminated.

[0177] After the risk of ice blockage is eliminated, the controller obtains the water molecule concentration ρ in the air extraction channel in real time and controls it according to two situations:

[0178] If ρ is greater than 10ppm (first preset value), the control valve 516 is kept at its current opening and continues to pump air until the absolute value of the pressure drop slope K stabilizes within a preset range greater than or equal to 0.1Pa / s (in this embodiment, the preset range is 0.1Pa / s to 0.15Pa / s). At this time, the controller outputs a control signal to control the control valve 516 to return to 100% opening and continue pumping air at the maximum pumping rate.

[0179] If ρ is less than or equal to 10ppm (first preset value), control valve 516 to keep the current opening unchanged and continue to pump air until the pipeline of the refrigeration system is close to a vacuum state.

[0180] During the process of reducing the opening of regulating valve 516, the minimum value of the adjustment range of regulating valve 516 is 25% of the maximum opening of regulating valve 516. That is, when the opening of regulating valve 516 is reduced to 25% of the maximum opening, the opening of regulating valve 516 will no longer decrease. This prevents the opening of regulating valve 516 from being too low, which could lead to stagnation of gas extraction and ensures that gaseous moisture in the refrigeration system's piping can be continuously extracted.

[0181] Furthermore, the vacuuming method for the refrigeration system also includes:

[0182] S3, when the water molecule concentration ρ is less than or equal to the first preset value, and the vacuum pressure reaches the first preset pressure value, the vacuuming is complete, and the vacuum pump 511 and / or regulating valve 516 are shut off. The vacuum pressure value is the pressure value detected by the vacuum pressure sensor 515 at the current moment, and the first preset pressure value is 5 × 10⁻⁶. - ²Pa.

[0183] When the vacuum pressure sensor 515 detects that the vacuum pressure value inside the connecting pipe 513 reaches 5×10 - When the pressure reaches 2Pa (first preset pressure value) and the water molecule concentration ρ is less than or equal to 10ppm (first preset value), the vacuuming is determined to be complete, the controller outputs a control signal, shuts down the vacuum pump 511 and the regulating valve 516, and ends the vacuuming process.

[0184] Furthermore, before performing the vacuuming operation, it is necessary to connect the vacuuming device 51 to the piping of the refrigeration system, specifically including:

[0185] S0, connect the vacuum pumping device 51 to the pipeline of the refrigeration system, obtain the sealing pressure in the vacuum channel, and determine whether there is a leak. If there is no leak, control the regulating valve 516 to be fully opened and enter the vacuum pumping process.

[0186] In practice, after connecting the vacuum pumping device 51 to the pipeline of the refrigeration system, the controller controls the regulating valve 516 to close to 0% opening, blocking the passage between the vacuum pump 511 and the pipeline of the refrigeration system, forming a closed and sealed detection chamber between the vacuum pump 511, the connecting pipe 513 and the pipeline of the refrigeration system; the vacuum pump 511 of the vacuum pumping device 51 starts briefly to begin vacuuming, and pumps the pressure in the pumping channel to the second preset pressure value (0.08MPa).

[0187] Turn off vacuum pump 511 and enter the 3-second pressure holding period;

[0188] Vacuum pressure sensor 515 collects pressure values ​​in real time during the pressure holding period, uploading a set of data to the controller every second. The controller calculates the pressure decay value ΔP1 during the pressure holding period, and the judgment rule is as follows:

[0189] A successful seal is determined when ΔP1 is less than or equal to 50Pa (preset attenuation value), indicating a reliable seal and no leakage.

[0190] Sealing failure: ΔP1 is greater than 50Pa (preset attenuation value), indicating that there is a gap in the connection and air leakage in the pipeline;

[0191] Qualified: Control valve 516 is opened to the initial opening degree (100%), vacuum pump 511 is started, and the formal vacuuming process begins;

[0192] Failure: The system triggers a workstation alarm. The three-dimensional moving unit automatically controls the self-positioning quick-connect connector 5124 to retract slightly by 1~2mm and then reconnect precisely, repeating the above sealing test process. If the test fails twice in a row, the central control unit 8 controls the AGV transport vehicle 71 to transfer the product to the welding and maintenance system, and records the docking failure information simultaneously.

[0193] In some embodiments of this application, the vacuum pressure sensor 515 collects pressure data in the pumping channel. Specifically, it automatically collects data once every second, and the pressure data is synchronously uploaded to the controller. The controller calculates the pressure drop slope based on the collected pressure data.

[0194] Specifically, the formula for calculating the pressure drop slope k is:

[0195]

[0196] in:

[0197] K is the pressure drop slope, in Pa / s;

[0198] P t1 The pressure inside the extraction channel at time t1 is expressed in Pa.

[0199] P t2The pressure inside the extraction channel at time t2 is expressed in Pa.

[0200] t2-t1 is the time interval, which is 1 second, meaning the pressure drop slope is calculated once per second.

[0201] The infrared moisture sensor 514 collects the moisture absorption spectrum data in the air extraction channel and uploads it to the controller simultaneously. The controller, based on the Beer-Lambert law, calculates the absorption intensity of the spectrum to quantitatively monitor the absolute water molecule concentration in the air extraction channel. When the moisture concentration is below 10 ppm, the air extraction channel is considered to have reached a dry state.

[0202] The expression for the Beer-Lambert law is:

[0203]

[0204] A represents absorbance, which is dimensionless;

[0205] I0 is the intensity of the incident infrared light, measured in W / m². 2 ;

[0206] I represents the intensity of infrared light after passing through the pipe, measured in W / m². 2 ;

[0207] The molar absorptivity of water molecules at a wavelength of 1.94 μm is taken as 1.8 × 10⁻⁶. 5 L / (mol·cm);

[0208] L is the optical path length of infrared light in the air extraction channel, which is the inner diameter of the air extraction channel, in cm.

[0209] c is the molar concentration of water molecules in the extraction channel, in mol / L. The mass concentration ρ can be obtained by conversion: ρ = c·M, where M is the molar mass of water, which is taken as 18 g / mol. When the mass concentration ρ is less than or equal to 10 ppm, the extraction channel is considered to be in a dry state.

[0210] Vacuum pump 511 is connected to the refrigeration system pipeline through the suction pipe (connecting pipe 513). Regulating valve 516 is connected in series on connecting pipe 513 to regulate the suction rate. Vacuum pressure sensor 515 and infrared moisture sensor 514 are both installed on connecting pipe 513, and their signal output terminals are electrically connected to the signal input terminal of the controller. The signal output terminal of the controller is electrically connected to the control terminal of regulating valve 516, forming a multivariable PID closed-loop feedback control loop.

[0211] The vacuuming method of the above-mentioned refrigeration system employs multivariable PID closed-loop feedback control, combined with real-time feedback from the water molecule concentration ρ monitored by the infrared moisture sensor 514 based on the Beer-Lambert law and the pressure drop slope K(t) monitored by the vacuum pressure sensor 515. This feedback is then used to precisely adjust the opening of valve 516 by substituting a clear PID opening expression: in the high moisture stage, the opening of valve 516 is fully opened to improve pumping efficiency; when there is a risk of ice blockage, the opening of valve 516 is adjusted through linear closed-loop control to prevent liquid water from freezing; after the moisture content reaches the target, the opening is stabilized until the target vacuum is achieved. This method effectively solves the ice blockage problem that easily occurs in traditional vacuuming methods, while balancing vacuuming efficiency and effectiveness. After vacuuming, the moisture content in the pumping channel is less than or equal to 10 ppm (reaching a dry state), and the vacuum pressure is stabilized at 5 × 10⁻⁶. - ²Pa, which meets the operating requirements of the refrigeration system.

[0212] The refrigeration system vacuuming method of this application embodiment is not only applicable to refrigerator refrigeration systems, but also to the pipeline vacuuming process of various refrigeration equipment such as air conditioners and cold storage. It only requires adjusting the preset values ​​(first preset value, second preset value K) according to the actual parameters of the equipment pipeline. set By keeping the first preset pressure value, PID opening expression and parameters, the working principle of the infrared moisture sensor 514, the relevant parameters of Beer-Lambert law and the concentration conversion relationship unchanged, precise, efficient and ice-block-free vacuum control can be achieved.

[0213] Furthermore, such as Figure 22 and Figure 23 As shown, once the ultimate vacuum level in the refrigeration system's piping reaches the standard and no moisture residue is confirmed, the automatic refrigerant charging device 52 takes over the refrigeration system's piping. The automatic refrigerant charging device 52 includes a vertical pump unit and a refrigerant charging self-positioning mechanism. Figure 22 As shown, the vertical pump unit includes an electromagnetic flow meter 521, a refrigerant delivery pipeline 522, a liquid injection servo valve 523, and a refrigerant storage tank 524. For example... Figure 23 As shown, the refrigerant self-positioning mechanism includes an XYZ stroke mechanism group 525, a CCD camera 526, and a refrigerant connector 527. The CCD camera 526 acquires image information of the refrigeration system's piping to determine the pipe position. The XYZ stroke mechanism group 525 drives the refrigerant connector 527 to move precisely in three-dimensional space and connect with the refrigeration system's piping. The refrigerant connector 527 is a self-sealing quick-connect connector with a one-way valve inside to prevent refrigerant leakage. After connection, the injection servo valve 523 opens, and the high-pressure liquid refrigerant in the refrigerant storage tank 524 is delivered to the refrigeration system through the refrigerant delivery pipeline 522. The electromagnetic flowmeter 521 monitors the refrigerant flow rate in real time with high measurement accuracy. The central control unit 8 controls the opening and closing of the injection servo valve 523 according to the set refrigerant charge amount to ensure charging accuracy.

[0214] like Figure 24 As shown, after the filling is completed and the pipeline is removed, the laser sealing robot 53 performs the sealing action. The laser sealing robot 53 includes a laser welding unit 531 and a welding robotic arm 532, which is a six-axis robotic arm. Figure 25 As shown, the laser welding unit 531 includes a laser welding head 5311, a 2D industrial camera 5312, and a fiber laser 5313. The 2D industrial camera 5312 acquires the position image of the process tube to determine the sealing position. The welding robotic arm 532 controls the laser welding head 5311 to collide and focus on the metal joint gap. The fiber laser 5313 emits a continuous fiber laser with a peak power of 3kW. The laser beam melts the copper tube metal instantly in microseconds, forming a dense metal molten pool. After cooling, the process tube is completely cut off, achieving a permanent high-strength metal metallurgical seal with high weld strength.

[0215] like Figure 26 As shown, finally, the leak detection robot 54 performs helium mass spectrometry leak detection. The leak detection robot 54 includes a redundant degree-of-freedom robotic arm 541 and a leak detection unit 542. The redundant degree-of-freedom robotic arm 541 is a seven-axis robotic arm, capable of flexible attitude adjustment within complex pipeline spaces. For example... Figure 27 As shown, the leak detection unit 542 includes a leak detection probe 5421, a hydrogen-nitrogen leak detector 5422, and an industrial camera 5423. The industrial camera 5423 acquires three-dimensional images of the refrigeration system's piping to determine the leak location. A redundant degree-of-freedom robotic arm 541 controls the leak detection probe 5421 to follow a set three-dimensional spatial trajectory, passing through each connection node of the compressor, condenser, dryer filter, and capillary tube, as well as all high-frequency weld surfaces. The hydrogen-nitrogen leak detector 5422 uses hydrogen molecule leak detection technology, which has high leak detection sensitivity, to perform final molecular-level micro-leak tests on each node. Simultaneously, combined with the internal pressure micro-attenuation data recorded by the central control unit 8, the product is compared to ensure that it meets the industry's long-term operation and leak-proof standards. After passing all tests, the finished product is transferred from the unloading unit 6 (using the unloading robot 61) to the AGV transport vehicle 71. The AGV transport vehicle 71 is then handed over to the stacker crane to be placed into the buffer shelf 72 of the finished product storage unit for storage. The buffer shelf 72 can store finished refrigerators, achieving flexible buffer storage of the finished products.

[0216] Specifically, in the automated assembly line of refrigerator refrigeration systems, the aforementioned vacuuming method, as a core operation in the deep evacuation and refrigerant injection process, is integrated into a complete closed-loop scheduling process. The operating logic of this production line is as follows:

[0217] The process begins with receiving production instructions. The central control unit 8 receives production order information from the MES system and parses the product model, production quantity, priority, and other information of the order.

[0218] Entering the dynamic scheduling and online stage, the central control unit 8 schedules the AGV transport vehicle 71 to complete the transfer of raw materials such as foam boxes, compressors, and evaporators according to the SLAM dynamic path planning algorithm. The loading unit 2 transfers the boxes to the pallet of the conveying device, and at the same time completes the RFID information binding of the materials to generate a production file with one code for each machine.

[0219] In the dual-machine collaborative assembly stage, the evaporator assembly robot and the compressor assembly robot work synchronously to complete the precise embedding of the evaporator and the screwless tightening assembly of the compressor, respectively.

[0220] Entering the flexible piping and induction welding stage, the piping robot completes the precise docking of the copper return pipe, exhaust pipe and compressor interface, and the high-frequency induction welding pipe robot performs flameless induction brazing operation.

[0221] Entering the weld non-destructive testing and diversion stage, the ultrasonic probes in the non-destructive testing room inspect all circumferential welds, and the system determines the weld quality based on the echo data;

[0222] Inspection and judgment process: If the inspection fails, the AGV transport vehicle 71 will transfer the defective product to the rework isolation unit, where the rework robot will carry out targeted rework on the defective weld. After the rework is completed, it must enter the inspection process again. Only after passing the inspection can it be transferred to the next process. If the inspection passes, it will enter the deep evacuation and refrigerant injection process.

[0223] During the deep evacuation and refrigerant injection process, the vacuuming device performs the above-mentioned vacuuming method. After confirming that the dryness of the air extraction channel meets the standard, the automatic refrigerant injection mechanism completes the quantitative injection of environmentally friendly refrigerant.

[0224] Entering the sealing and final leak detection stage, the laser sealing robot completes the laser sealing welding of the process tube, and the leak detection robot performs molecular-level micro-leak detection on all connection nodes of the refrigeration system.

[0225] Finally, the finished product is taken off the production line and put into storage. The unloading unit 6 transfers the qualified finished product to the AGV transport vehicle 71, and the stacking robot 12 stores the finished product into the buffer shelf 72, completing the entire production process.

[0226] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0227] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for evacuating a refrigeration system, characterized in that, include: Real-time acquisition of vacuum pressure, pressure drop slope, and water molecule concentration within the air extraction channel; A multivariable PID closed-loop feedback control model is constructed, using the vacuum pressure value, pressure drop slope and water molecule concentration as feedback inputs, and the opening of the regulating valve in the air extraction channel is adjusted in real time through the PID algorithm. When the water molecule concentration is greater than the first preset value and the pressure drop slope is greater than or equal to the second preset value, the control valve is fully opened to create a vacuum at the maximum pumping rate. When the water molecule concentration is greater than the first preset value and the pressure drop slope is less than the second preset value, the pressure drop slope is the controlled variable and the second preset value is the PID control target value. Combined with the real-time feedback of water molecule concentration, the PID algorithm reduces the opening of the regulating valve and reduces the pumping rate, so that the pressure drop slope is stabilized within the range of greater than or equal to the second preset value. When the water molecule concentration is less than or equal to the first preset value, the control valve is kept at its current opening until the vacuum pressure reaches the first preset pressure value. The method of reducing the valve opening and decreasing the pumping rate using the PID algorithm also includes: The opening of the regulating valve is reduced in real time by the PID algorithm until the infrared moisture sensor detects that the attenuation value of the absorption intensity reaches the preset attenuation value. It is then determined that the liquid water has been gently extracted in gaseous form, and the risk of ice blockage is eliminated. After the risk of ice blockage is eliminated, the water molecule concentration in the air extraction channel is monitored in real time. If the water molecule concentration is greater than the first preset value, control the regulating valve to maintain the current opening until the pressure drop slope stabilizes within a preset range greater than or equal to the second preset value, and then control the regulating valve to restore the maximum opening. If the water molecule concentration is less than or equal to the first preset value, the control valve will maintain its current opening and continue pumping air.

2. The vacuuming method for a refrigeration system according to claim 1, characterized in that, The method of reducing the valve opening and decreasing the pumping rate using the PID algorithm includes: The PID algorithm is used to reduce the opening of the regulating valve in real time according to the deviation of the pressure drop slope.

3. The vacuuming method for a refrigeration system according to claim 1, characterized in that, The method of reducing the valve opening and decreasing the pumping rate using the PID algorithm includes: Using a second preset value as the target value for PID control, the deviation between the current pressure drop slope and the second preset value is obtained; the opening of the regulating valve is reduced in real time through the PID algorithm, and the reduction in the opening of the regulating valve is linearly related to the deviation value.

4. The vacuuming method for a refrigeration system according to claim 3, characterized in that, During the process of reducing the opening of the regulating valve and decreasing the pumping rate by using the PID algorithm, the minimum value of the adjustment range of the regulating valve opening is 25% of the maximum opening of the regulating valve.

5. The vacuuming method for a refrigeration system according to any one of claims 1-4, characterized in that, Also includes: When the water molecule concentration is less than or equal to the first preset value and the vacuum pressure reaches the first preset pressure value, the vacuuming is completed, and the vacuum pump and / or regulating valve are turned off.

6. The vacuuming method for a refrigeration system according to claim 1, characterized in that, Also includes: Connect the vacuuming device to the piping of the refrigerator's refrigeration system, obtain the sealing pressure in the vacuum channel, and determine whether there is a leak. If there is no leak, control the regulating valve to be fully opened and enter the vacuuming process.

7. The vacuuming method for a refrigeration system according to claim 5, characterized in that, Also includes: After docking, the vacuum pump of the vacuum pumping device is started, and the pressure in the pumping channel is pumped to the second preset pressure value. Pressure holding; Obtain the vacuum pressure decay value during the pressure holding period, and determine whether there is a leak based on the vacuum pressure decay value and the preset decay value.

8. The vacuuming method for a refrigeration system according to claim 1, characterized in that, The real-time acquisition of vacuum pressure, pressure drop slope, and water molecule concentration within the air extraction channel includes: A vacuum pressure sensor is used to collect pressure data in the air extraction channel, including the vacuum pressure value, and the pressure drop slope is obtained from the pressure data. An infrared moisture sensor is used to collect moisture absorption spectrum data in the air extraction channel, and the water molecule concentration is obtained from the moisture absorption spectrum data combined with Beer-Lambert's law.

9. A vacuuming device for a refrigeration system, used to perform the vacuuming method as described in any one of claims 1-8, characterized in that, include: vacuum pump, The self-positioning insertion mechanism is connected to the vacuum pump via a connecting pipe and is used for a sealed connection with the piping of the refrigeration system. An infrared moisture sensor is mounted on the connecting tube and is used to detect the moisture absorption spectrum data inside the connecting tube. A vacuum pressure sensor is installed on the connecting pipe to detect pressure data inside the connecting pipe; An adjusting valve is installed inside the connecting pipe to adjust the effective cross-sectional area of ​​the air extraction channel inside the connecting pipe; The controller is electrically connected between the infrared moisture sensor, the vacuum pressure sensor, and the regulating valve. The controller is configured to construct a multivariable PID closed-loop feedback control model and use moisture absorption spectrum data and pressure data as feedback inputs to adjust the opening degree of the regulating valve and / or the operating frequency of the vacuum pump in real time through a PID algorithm.

10. The vacuum pumping device for a refrigeration system according to claim 9, characterized in that, The self-positioning insertion mechanism includes a three-dimensional moving unit, a positioning vision camera, and a self-positioning quick connector. The positioning vision camera and the self-positioning quick connector are located at the end of the three-dimensional moving unit. The positioning vision camera is configured to acquire the three-dimensional spatial position of the pipe connection port of the refrigeration system, and the self-positioning quick connector is used for sealing connection with the pipe of the refrigeration system.

11. The vacuum pumping device for a refrigeration system according to claim 9, characterized in that, The controller is configured to: calculate the pressure drop slope based on the pressure data collected by the vacuum pressure sensor in the air extraction channel, and obtain the water molecule concentration based on the moisture absorption spectrum data collected by the infrared moisture sensor in the air extraction channel combined with the Beer-Lambert law.

12. A smart manufacturing production line for assembling a refrigeration system, characterized in that, The system includes a conveying device and, sequentially arranged along the conveying direction of the conveying device, a raw material storage unit, a feeding unit, a refrigeration system assembly unit, a welding and maintenance unit, a refrigerant injection and sealing inspection unit, a unloading unit, and a finished product storage unit. The raw material storage unit stores compressors and evaporators to be assembled. The feeding unit transports the compressors and evaporators to the refrigeration system assembly unit, which assembles the compressors and evaporators onto the refrigerator chassis. The welding and maintenance unit performs piping, welding, and welding quality inspection of the compressors and evaporators. The refrigerant injection and sealing inspection unit includes a vacuuming device, an automatic refrigerant injection device, a sealing device, and a leak detection device as described in any one of claims 9 to 11. The unloading unit transports leak-tested finished products to the finished product storage unit for storage.

13. The intelligent manufacturing production line for refrigeration system assembly according to claim 12, characterized in that, The refrigeration system assembly unit includes a compressor assembly robot and an evaporator assembly robot, which are arranged opposite each other on both sides of the conveying device to simultaneously assemble the compressor and the evaporator onto the refrigerator chassis.

14. The intelligent manufacturing production line for refrigeration system assembly according to claim 13, characterized in that, The compressor assembly robot includes a first robotic arm, an eccentric flange, a first gripping mechanism, and a tightening fastener. The eccentric flange is connected between the first robotic arm and the first gripping mechanism so that the first robotic arm and the first gripping mechanism are eccentrically positioned. The first gripping mechanism is used to grip the compressor. The tightening fastener is correspondingly inserted into the mounting hole of the compressor base, and the tightening fastener can partially penetrate into the locking hole of the refrigerator chassis under the action of external force and elastically abut against the hole wall of the locking hole.

15. The intelligent manufacturing production line for refrigeration system assembly according to claim 14, characterized in that, The expansion locking fastener includes an elastic expansion part, a buffer pad, and a pressing part arranged sequentially along the axial direction. The elastic expansion part passes through the locking hole and elastically abuts against the hole wall of the locking hole. The buffer pad is located between the base of the compressor and the refrigerator chassis. The pressing part is located on the upper side of the mounting hole and elastically presses against the base of the compressor to fix the compressor to the refrigerator chassis.

16. The intelligent manufacturing production line for refrigeration system assembly according to any one of claims 12-15, characterized in that, It also includes a rework isolation unit, which is used to receive products that fail the inspection by the sampling and sealing unit, repair them, and return them to the sampling and sealing unit.

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