A welding apparatus and method for air conditioner compressor cast components

Abstract

This invention relates to the field of welding technology and provides a welding apparatus and method for casting components of an air conditioning compressor. The welding apparatus includes a housing connected to a horizontal moving mechanism. Two infrared quartz radiation plates are positioned opposite each other on the inner sidewall of the housing. A composite welding torch assembly includes a coaxial composite welding torch and an annular TIG arc nozzle. The coaxial composite welding torch has a central laser beam channel and an annular TIG arc nozzle surrounding the central laser beam channel. The coaxial composite welding torch is connected to the top of the housing via a piezoelectric ceramic micro-motion oscillation platform, and an elastic corrugated sealing sleeve connects the piezoelectric ceramic micro-motion oscillation platform to the top of the housing. In this invention, by setting a weld pool state evaluation module, a weld pool stability index is output based on the weld pool width fluctuation rate, weld pool tail oscillation frequency, and trailing angle deviation, enabling real-time quantification of the dynamic stability of the weld pool.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, and particularly relates to a welding apparatus and method for casting components of an air conditioning compressor. Background Technology

[0002] Cast components of air conditioning compressors, including key parts such as cylinders, upper covers, lower covers, and distributors, must be welded together during manufacturing to ensure sealing performance and structural strength. Laser-TIG hybrid welding technology, combining the high energy density of laser deep penetration welding with the bridging ability and stability of TIG arcs, has significant application value in welding cast components. However, current welding equipment still has significant shortcomings in practical applications.

[0003] The stability of the weld pool is affected by a variety of factors, but existing technologies rely on monitoring only a single parameter, such as focusing only on the weld pool width or arc voltage. They have failed to establish a comprehensive evaluation mechanism for the weld pool width fluctuation rate, the weld pool tail oscillation frequency and the trailing angle deviation, resulting in the inability to accurately quantify the real-time stability status of the weld pool.

[0004] Meanwhile, dust interference during the welding process also has a critical impact on the final quality. However, existing systems treat these factors in isolation or only issue simple threshold alarms, lacking the comprehensive evaluation capability of nonlinearly coupling the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component.

[0005] In addition, most control strategies are open-loop control or single-variable adjustment based on a single feedback signal. When the welding state fluctuates, only the laser power or welding speed is adjusted, ignoring the need for coordinated optimization between oscillation frequency and moving speed, and thus failing to achieve dual-parameter linkage control.

[0006] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0007] The purpose of this invention is to provide a welding apparatus and method for casting components of an air conditioning compressor, in order to solve the above-mentioned problems.

[0008] The present invention is implemented as follows: a welding device for casting components of an air conditioner compressor includes a housing, the housing is connected to a horizontal moving mechanism, and two infrared quartz radiation plates are arranged at opposite positions on the inner sidewall of the housing.

[0009] A composite welding torch assembly includes a coaxial composite welding torch and an annular TIG arc nozzle. The coaxial composite welding torch has a central laser beam channel and an annular TIG arc nozzle surrounding the central laser beam channel. The coaxial composite welding torch is connected to the top of the housing via a piezoelectric ceramic micro-motion oscillation platform. An elastic corrugated sealing sleeve is connected between the piezoelectric ceramic micro-motion oscillation platform and the top of the housing. The welding nozzle of the coaxial composite welding torch extends into the interior of the housing through the top wall of the housing.

[0010] A high-temperature resistant metal wire brush is located at the bottom front side of the housing, and a dust removal component is installed inside the housing.

[0011] The online detection module is used to collect the status of the weld pool, the dust concentration in the shell, and the status parameters of the composite welding gun assembly during welding.

[0012] It also includes a control system, connected to the online detection module, which includes:

[0013] The weld pool condition assessment module is used to output the weld pool stability index based on the weld pool width fluctuation rate, weld pool tail oscillation frequency and trailing angle deviation.

[0014] The comprehensive evaluation module is used to output a comprehensive evaluation index based on the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component.

[0015] The frequency control module is used to optimize the output frequency based on the comprehensive evaluation index and the current oscillation frequency of the composite welding gun assembly.

[0016] The speed control module is used to output an optimized movement speed based on the optimized frequency, comprehensive evaluation index, and the current movement speed of the composite welding torch assembly.

[0017] A further technical solution includes an online detection module comprising a coaxial vision sensor, a dust concentration sensor, an infrared thermal imager, an arc parameter acquisition unit, and a laser back-reflection light sensor. The coaxial vision sensor is installed outside the central laser beam channel of the coaxial composite welding torch, coaxially with the laser beam to acquire images of the molten pool. The dust concentration sensor and the infrared thermal imager are installed on the inner wall of the housing to acquire the two-dimensional temperature field distribution of the weld zone. The arc parameter acquisition unit is connected to the welding power supply of the annular TIG arc nozzle to acquire the arc voltage in real time. The laser back-reflection light sensor is coupled and installed outside the central laser beam channel via a beam splitter, separating a portion of the signal light from the main laser beam to acquire the intensity of the laser signal reflected back from the molten pool aperture in real time.

[0018] In a further technical solution, the infrared quartz radiation plates are all independently controlled by a programmable temperature field controller for gradient preheating and slow cooling of the weld position. The programmable temperature field controller stores a nonlinear temperature curve corresponding to the material of the cast component. The curve sequentially forms a preheating zone, a constant temperature welding zone, and a slow cooling zone along the welding direction. The temperature in the slow cooling zone decreases nonlinearly in a stepwise manner to below the welding crack sensitivity temperature threshold corresponding to the material.

[0019] In a further technical solution, the dust removal component includes a flow guide baffle, which is disposed at the top of the inner side of the housing, and a filter box and an air pump are disposed in the flow guide baffle.

[0020] A further technical solution is that two rows of conical positioning rollers are provided on both sides of the outer shell, with the large end of each conical positioning roller close to the outer shell and the small end away from the outer shell.

[0021] In a further technical solution, the weld pool stability index in the weld pool condition assessment module is obtained through the following method:

[0022] Calculate the first factor, which is 1 minus the ratio of the melt pool width deviation index to the allowable range of melt pool width deviation;

[0023] Calculate the second factor, which is 1 minus the ratio of the oscillation frequency at the tail of the molten pool to the allowable range of oscillation frequency;

[0024] Calculate the third factor, which is 1 minus the ratio of the absolute deviation index of the trailing angle to the allowable range of the absolute deviation of the trailing angle;

[0025] Multiplying the first factor, the second factor, and the third factor together yields the weld pool stability index.

[0026] Further technical solutions, in the comprehensive evaluation module, the comprehensive evaluation index is obtained through the following methods:

[0027] The dust influence correction coefficient, arc length stability component, and keyhole stability component are calculated separately. The dust influence correction coefficient is equal to 1 minus the ratio of the measured dust concentration to the saturation concentration threshold. The arc length stability component is equal to 1 minus the relative fluctuation amplitude of the arc voltage (the ratio of the standard deviation to the mean) divided by the maximum allowable relative fluctuation amplitude under typical process conditions. The keyhole stability component is equal to 1 minus the relative fluctuation amplitude of the laser back-reflected light intensity (the ratio of the standard deviation to the mean) divided by the maximum allowable relative fluctuation amplitude under typical process conditions.

[0028] Select the minimum value from the weld pool stability index, dust influence correction coefficient, arc length stability component and keyhole stability component as the first item, and select the maximum and minimum values;

[0029] Calculate (1 minus the difference between the maximum and minimum values ​​divided by 4) to obtain the second term;

[0030] The coupling coefficient is calculated by multiplying the absolute value of the difference between the weld pool stability index and the arc length stability component, and then multiplying it by the absolute value of the difference between the dust influence correction coefficient and the keyhole stability component to obtain the third term.

[0031] Subtract the third term from the product of the first and second terms, and limit the result to above 0 to obtain the comprehensive evaluation index.

[0032] In a further technical solution, the optimized oscillation frequency in the frequency control module is obtained through the following method:

[0033] Calculate the difference between the basic oscillation frequency and the maximum permissible oscillation frequency, multiply it by (1 minus the comprehensive evaluation index) to obtain the frequency adjustment amount;

[0034] The optimized oscillation frequency is obtained by adding the base oscillation frequency to the frequency adjustment.

[0035] In a further technical solution, the optimized movement speed in the speed control module is achieved through the following methods:

[0036] Calculate the difference between the optimized oscillation frequency and the basic oscillation frequency, divide it by the difference between the maximum allowable oscillation frequency and the basic oscillation frequency, and obtain the relative frequency adjustment amount;

[0037] Calculate (1 plus the product of the speed sensitivity coefficient and the relative frequency adjustment) to obtain the speed adjustment factor;

[0038] Multiply the base movement speed by the comprehensive evaluation index, and then divide by the speed adjustment factor to obtain the optimized movement speed.

[0039] A welding method for cast components of an air conditioning compressor, applied to any of the above-described devices, includes the following steps:

[0040] S1: Place the air conditioner compressor casting component to be welded inside the housing, and move the housing through the horizontal moving mechanism to align the weld seam with the composite welding gun assembly;

[0041] S2: Real-time acquisition of weld pool status, dust concentration inside the shell, and status parameters of the composite welding gun assembly during welding via online detection module;

[0042] S3: The weld pool condition assessment module in the control system outputs the weld pool stability index based on the weld pool width fluctuation rate, weld pool tail oscillation frequency and trailing angle deviation.

[0043] S4: The comprehensive evaluation module in the control system outputs a comprehensive evaluation index based on the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component.

[0044] S5: The frequency control module in the control system outputs an optimized frequency based on the comprehensive evaluation index and the current oscillation frequency of the composite welding gun assembly.

[0045] S6: The speed control module in the control system outputs the optimized movement speed based on the optimized frequency, comprehensive evaluation index, and the current movement speed of the composite welding gun assembly.

[0046] S7: Control the piezoelectric ceramic micro-motion oscillation platform and the horizontal movement mechanism according to the optimized frequency and optimized moving speed respectively.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] By setting up a weld pool condition assessment module, the weld pool stability index is output based on the weld pool width fluctuation rate, weld pool tail oscillation frequency, and trailing angle deviation, which can quantify the dynamic stability of the weld pool in real time. Combined with the comprehensive assessment module's comprehensive judgment of multiple factors such as dust, arc length, and keyhole, the generation of defects such as porosity and lack of fusion during the welding process is effectively avoided, which is especially suitable for precision welding of air conditioning compressor casting components.

[0049] Through the frequency control module and speed control module, based on the comprehensive evaluation index calculated in real time, the oscillation frequency and moving speed of the composite welding gun assembly are automatically optimized, so that the welding parameters can follow the changes in the weld pool state, dust concentration and arc and keyhole stability in real time without manual intervention, which significantly improves the adaptability of the welding device to different materials and working conditions.

[0050] By setting up an independently controllable infrared quartz radiation plate and a programmable temperature field controller, a preheating zone, a constant temperature welding zone, and a nonlinear stepped slow cooling zone can be formed along the welding direction. The temperature in the slow cooling zone drops stepwise to below the welding crack sensitive temperature threshold, which significantly reduces the risk of hot cracks in the casting components of the air conditioning compressor during welding and cooling, and improves the microstructure of the weld and heat-affected zone.

[0051] By installing a high-temperature resistant metal wire brush at the bottom front of the housing, in conjunction with the dust removal components inside the housing (including a baffle, filter box, and air pump), metal dust generated during the welding process can be effectively removed and filtered. At the same time, a dust influence correction coefficient is introduced into the comprehensive evaluation module, enabling the control system to dynamically adjust the welding strategy according to the measured dust concentration, further ensuring the stability and consistency of laser-arc hybrid welding. Attached Figure Description

[0052] Figure 1 This is a front view schematic diagram of the internal structure of the outer shell in this invention;

[0053] Figure 2 This is a schematic diagram of the internal structure of the outer shell in this invention;

[0054] Figure 3 This is a schematic diagram of the overall structure of the present invention;

[0055] Figure 4 This is a schematic diagram of the composite welding gun assembly in this invention;

[0056] Figure 5 This is a schematic diagram of the control system modules in this invention;

[0057] Figure 6 A schematic diagram of the welding process for cast components of an air conditioning compressor.

[0058] In the attached diagram: 1. Outer shell; 2. Conical positioning roller; 3. Composite welding torch assembly; 31. Coaxial composite welding torch; 32. Annular TIG arc nozzle; 4. Dust removal assembly; 41. Flow guide baffle; 42. Filter box; 43. Air pump; 5. Elastic corrugated sealing sleeve; 6. Infrared quartz radiation plate; 7. High-temperature resistant metal wire brush; 8. Piezoelectric ceramic micro-motion oscillation platform. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0060] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0061] like Figures 1-5 As shown, a welding device for casting components of an air conditioner compressor is provided in an embodiment of the present invention. It includes a housing 1, which is connected to a horizontal moving mechanism. Two infrared quartz radiation plates 6 are arranged at opposite positions on the inner sidewall of the housing 1.

[0062] The composite welding torch assembly 3 includes a coaxial composite welding torch 31 and an annular TIG arc nozzle 32. The coaxial composite welding torch 31 has a central laser beam channel and an annular TIG arc nozzle 32 surrounding the central laser beam channel. The coaxial composite welding torch 31 is connected to the top of the housing 1 through a piezoelectric ceramic micro-motion oscillation platform 8. An elastic corrugated sealing sleeve 5 is connected between the piezoelectric ceramic micro-motion oscillation platform 8 and the top of the housing 1. The welding nozzle of the coaxial composite welding torch 31 extends into the interior of the housing 1 through the top wall of the housing 1.

[0063] A high-temperature resistant metal wire brush 7 is disposed at the bottom front side of the housing 1, and a dust removal component 4 is disposed inside the housing 1.

[0064] The online detection module is used to collect the status of the weld pool, the dust concentration in the outer shell 1, and the status parameters of the composite welding gun assembly 3 during welding.

[0065] It also includes a control system, connected to the online detection module, which includes:

[0066] The weld pool condition assessment module is used to output the weld pool stability index based on the weld pool width fluctuation rate, weld pool tail oscillation frequency and trailing angle deviation.

[0067] The comprehensive evaluation module is used to output a comprehensive evaluation index based on the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component.

[0068] The frequency control module is used to optimize the output frequency based on the comprehensive evaluation index and the current oscillation frequency of the composite welding gun assembly 3.

[0069] The speed control module is used to optimize the moving speed based on the optimized frequency, comprehensive evaluation index, and the current moving speed output of the composite welding torch assembly 3.

[0070] In this embodiment, the cast component to be welded is first placed on a horizontal moving mechanism. When the welding device starts working, the housing 1 moves along the welding path via the horizontal moving mechanism. During the movement, the high-temperature resistant metal wire brush 7, located at the bottom front side of the housing 1, first contacts the surface of the cast component to pre-clean the weld area, removing oxide scale and oil stains from the surface, creating good surface conditions for subsequent welding.

[0071] Subsequently, the composite welding torch assembly 3 begins operation. The welding nozzle of the coaxial composite welding torch 31 extends into the housing 1 through the elastic corrugated sealing sleeve 5. The laser beam and TIG arc simultaneously act on the area to be welded, forming a molten pool. During this process, the online detection module continues to operate, with its internal sensors acquiring data in real time. For example, an industrial camera continuously acquires images of the molten pool to analyze the molten pool width fluctuation rate and the oscillation frequency at the tail of the molten pool; a particulate sensor monitors the dust concentration inside the housing 1; and a current and voltage sensor acquires parameters of the TIG arc.

[0072] The collected data is transmitted to the control system. The weld pool condition assessment module in the control system first processes the weld pool image data, calculates the weld pool width fluctuation rate, the weld pool tail oscillation frequency, and the trailing angle deviation, and outputs a weld pool stability index based on these parameters.

[0073] Next, the comprehensive evaluation module receives the weld pool stability index and combines it with dust concentration data (used to calculate the dust influence correction coefficient), arc parameters (used to calculate the arc length stability component), and other possible data (e.g., if a laser backscatter sensor is present, its data is used to calculate the keyhole stability component) collected by the online detection module to perform a comprehensive evaluation and output a comprehensive evaluation index. This index comprehensively reflects the overall health of the current welding process.

[0074] Based on the comprehensive evaluation index output by the comprehensive evaluation module, the frequency control module and the speed control module in the control system begin to work together. The frequency control module calculates and outputs an optimized oscillation frequency based on the current comprehensive evaluation index and the oscillation frequency of the composite welding torch assembly 3. For example, if the comprehensive evaluation index indicates poor welding conditions, the frequency control module may suggest reducing the oscillation frequency to increase the stabilization time of the molten pool. Simultaneously, the speed control module calculates and outputs an optimized movement speed based on this optimized frequency, the comprehensive evaluation index, and the current movement speed.

[0075] Throughout the welding process, the dust removal component 4 inside the outer casing 1 operates continuously, drawing in and filtering the welding fumes to keep the interior of the casing 1 clean and prevent fumes from interfering with the optical components and the welding process. Simultaneously, the infrared quartz radiation plate 6 on the inner wall of the outer casing 1 can preheat or slowly cool the weld area as needed. For example, it can locally preheat the cast components before welding begins or slowly cool them after welding to reduce thermal stress and lower the risk of cracking. In this way, the entire device achieves multi-dimensional monitoring, multi-factor evaluation, and multi-parameter linkage control of the welding process of the air conditioning compressor cast components, thereby effectively improving welding quality and stability.

[0076] In a preferred embodiment of the present invention, the online detection module includes a coaxial vision sensor, a dust concentration sensor, an infrared thermal imager, an arc parameter acquisition unit, and a laser back-reflection light sensor. The coaxial vision sensor is installed outside the central laser beam channel of the coaxial composite welding torch 31 and acquires the molten pool image coaxially with the laser beam. The dust concentration sensor and the infrared thermal imager are installed on the inner wall of the outer shell 1 and are used to acquire the two-dimensional temperature field distribution of the weld zone. The arc parameter acquisition unit is connected to the welding power supply of the annular TIG arc nozzle 32 and is used to acquire the arc voltage in real time. The laser back-reflection light sensor is coupled and installed outside the central laser beam channel through a beam splitter and splits a portion of the signal light from the main laser beam to acquire the intensity of the laser signal reflected back from the molten pool aperture in real time.

[0077] In this embodiment, the coaxial vision sensor is a device capable of maintaining a coaxial relationship with the laser beam and acquiring real-time images of the weld pool area. Its core lies in aligning the image acquisition path with the laser transmission path through an optical system, ensuring that the sensor can "see" the laser's point of action and the surrounding state of the weld pool. This sensor can employ an optical system with a beam splitter or polarizing beam splitter to reflect the visible or near-infrared image of the weld pool to a CMOS or CCD camera, while allowing the main laser beam to pass through.

[0078] A dust concentration sensor is a device used to monitor the content of solid particulate matter in a gas in real time. In welding environments, it is mainly used to detect the concentration of metal fumes and particulate matter generated during the welding process. This sensor uses the principle of light scattering, calculating the dust concentration by measuring the intensity of light scattered by dust particles.

[0079] An infrared thermal imager is a device that uses the principle of infrared radiation to convert the invisible infrared energy emitted by the surface of an object into a visible thermal image. In welding applications, it can acquire the two-dimensional temperature field distribution of the weld area in real time. This thermal imager can use an uncooled focal plane array detector to generate a thermal image by detecting the intensity of infrared radiation emitted by the object.

[0080] An arc parameter acquisition unit is a device used to monitor and record electrical parameters related to the welding arc in real time, mainly including arc voltage and current. This acquisition unit can consist of high-precision voltage and current sensors, and can be directly connected to the output of the welding power source or the arc circuit.

[0081] A laser backscattered light sensor is a device used to detect the intensity of a laser signal reflected from inside a pinhole in a weld pool. The stability of the pinhole is closely related to the intensity of the reflected light; therefore, this sensor can be used to assess the stability of the pinhole. The sensor can use a photodiode or avalanche photodiode as a detector, receiving the reflected light through an optical fiber or free-space optical system and converting it into an electrical signal.

[0082] The online detection module of this application integrates multiple sensors to construct a multi-dimensional, high-precision welding status data acquisition system. A coaxial vision sensor is installed outside the central laser beam channel of the coaxial composite welding torch 31, coaxial with the laser beam, enabling real-time acquisition of clear images of the molten pool. This provides raw data for subsequent calculations of key parameters such as molten pool width, tail oscillation frequency, and trailing angle. A dust concentration sensor and an infrared thermal imager are installed on the inner wall of the housing 1, respectively used to monitor the dust concentration in the welding area and the two-dimensional temperature field distribution of the weld seam in real time. These data are crucial for assessing the impact of the environment on welding quality and the effects of preheating and post-weld slow cooling. The arc parameter acquisition unit is directly connected to the welding power supply of the annular TIG arc nozzle 32, acquiring the arc voltage in real time to reflect the stability of the arc. A laser back-reflection light sensor is coupled to the outside of the central laser beam channel via a beam splitter, separating a portion of the signal light from the main laser beam to acquire the intensity of the laser signal reflected back from the molten pool aperture in real time, thereby monitoring the aperture's stability.

[0083] In a preferred embodiment of the present invention, the infrared quartz radiation plates 6 are all independently controlled by a programmable temperature field controller for gradient preheating and slow cooling of the weld position. The programmable temperature field controller stores a nonlinear temperature curve corresponding to the material of the cast component. The curve sequentially forms a preheating zone, a constant temperature welding zone, and a slow cooling zone along the welding direction. The temperature in the slow cooling zone decreases nonlinearly in a stepwise manner to below the welding crack sensitive temperature threshold corresponding to the material.

[0084] In this embodiment, the infrared quartz radiating plate 6 is a component used to heat the welding area. Its independent control means that each radiating plate 6 can adjust its heating power or temperature individually as needed, rather than being uniformly controlled. This independent control capability is a key foundation for achieving a gradient temperature field along the welding direction. For example, each infrared quartz radiating plate 6 can be equipped with an independent power module and temperature sensor, achieving precise temperature regulation through its own closed-loop control circuit.

[0085] The programmable temperature field controller is the core unit for achieving precise temperature control. This controller not only receives temperature feedback signals and outputs control commands to the infrared quartz radiating plate 6, but also has the ability to store and execute complex temperature curves. This controller can be a microprocessor-based embedded system that integrates PID control algorithms and data storage modules.

[0086] The programmable temperature field controller stores nonlinear temperature curves corresponding to the materials of the cast components. This means that the controller's internal non-volatile memory pre-stores temperature control strategies optimized for different cast component materials. These curves can be discrete data point sequences, generating continuous control commands through interpolation algorithms; or they can be parameterized mathematical models, with model parameters adjusted to adapt to the characteristics of different materials. This storage capability allows the system to automatically select or apply the most suitable preheating and slow cooling schemes based on the material of the workpiece to be welded.

[0087] The curve sequentially forms a preheating zone, a constant-temperature welding zone, and a slow-cooling zone along the welding direction. This indicates that different locations on the workpiece experience different temperature stages during the welding process. The preheating zone aims to gradually increase the temperature of the weld area before welding to reduce temperature differences and thermal stress during welding. The constant-temperature welding zone maintains a stable temperature in the weld area during welding to ensure good formation and solidification of the molten pool. The slow-cooling zone gradually reduces the temperature of the weld area in a controlled manner after welding to avoid embrittlement and cracking caused by rapid cooling. This zone division can be achieved through time-series control (i.e., the controller switches to the temperature strategy of the next zone as welding time progresses) or spatial position control (i.e., when the weld moves to a specific position, the corresponding radiant plate 6 executes the temperature strategy of that zone).

[0088] The temperature in the slow cooling zone decreases non-linearly in a stepwise manner until it falls below the weld crack sensitivity threshold corresponding to the material. This is a refined temperature control strategy. The non-linear stepwise decrease means that the temperature does not decrease at a constant rate, but rather gradually decreases in a way that better conforms to metallurgical principles, based on material properties and crack sensitivity. For example, the temperature decreases rapidly at high temperatures, but slows down as it approaches the weld crack sensitivity threshold. The weld crack sensitivity threshold is the critical temperature at which cracks easily form in the cooling process of a specific cast component material. Lowering the temperature below this threshold is crucial to preventing cold crack formation. This temperature decrease can be achieved by the controller executing a preset exponential decay function, a multi-segment linear function, or an adaptive algorithm based on a thermodynamic model.

[0089] This application's solution utilizes a programmable temperature field controller to independently control two infrared quartz radiation plates 6, thereby creating a gradient temperature field that varies along the welding direction at the weld seam of the air conditioner compressor casting component. Before welding begins, the controller selects or generates a corresponding temperature control strategy from its stored nonlinear temperature curve library based on the material of the casting component to be welded. When the welding process starts, the infrared quartz radiation plate 6 located at the front of the welding path first executes the temperature curve of the preheating zone, gradually increasing the temperature of the weld seam area. As welding progresses, when the weld seam area enters the welding position, the corresponding infrared quartz radiation plate 6 switches to the temperature control mode of the constant temperature welding zone to ensure temperature stability during the welding process. After the weld seam leaves the welding area, the infrared quartz radiation plate 6 located at the rear of the welding path begins to execute the temperature curve of the slow cooling zone, gradually reducing the temperature of the weld seam area in a nonlinear, step-like manner until it falls below the welding crack sensitivity temperature threshold of the material. The entire process, through the independent and dynamic adjustment of each infrared quartz radiation plate 6 by the programmable temperature field controller, achieves precise and real-time control of the temperature field in the welding area, effectively avoiding the limitations of traditional heating methods. This refined temperature management, in conjunction with the horizontal movement mechanism of the housing 1, ensures that the cast components receive optimal temperature conditions throughout the welding path, thereby significantly improving welding quality.

[0090] like Figure 1 and Figure 2 As shown, in a preferred embodiment of the present invention, the dust removal assembly 4 includes a flow guide baffle 41, which is disposed at the top of the inner side of the housing 1, and a filter box 42 and an air pump 43 are disposed in the flow guide baffle 41.

[0091] In this embodiment, the proposed solution cleverly integrates the flow-guiding filter dust removal structure inside the outer casing 1, achieving efficient fume collection and treatment without interfering with the welding operation. Specifically, utilizing the physical property of welding fumes naturally rising and diffusing under heat, the flow-guiding baffle 41 is positioned at the top inner side of the outer casing 1. This arrangement effectively guides the fumes to naturally gather towards the top area of ​​the outer casing 1, thus preventing the fumes from drifting randomly inside the outer casing 1 and contaminating internal components, particularly protecting the central laser beam channel of the coaxial composite welding torch 31 in the composite welding torch assembly 3 and the optical sensors in the online detection module. Simultaneously, since the flow-guiding baffle 41 is located at the top, it does not occupy space in the welding work area, thus not interfering with the oscillation operation of the coaxial composite welding torch 31, workpiece positioning, or other welding operations. Furthermore, the filter box 42 and air pump 43 are integrated inside the flow-guiding baffle 41. The air pump 43 provides stable suction, drawing the fumes gathered at the top into the filter box 42. The filter box 42 is responsible for filtering and trapping the fumes, ensuring the purified gas is discharged. This design creates a complete processing path from smoke and dust diversion and gathering to suction and filtration, which not only ensures dust removal efficiency but also avoids the problems that traditional external independent smoke exhaust structures may cause, such as interference with airflow in the welding area and affecting arc stability.

[0092] In this way, the present application can effectively protect the optical components inside the housing 1, prevent the laser energy from being attenuated by the smoke and dust, ensure the stable progress of the welding process, and thus ensure that the online detection module can accurately collect the weld pool status, dust concentration, and the status parameters of the composite welding gun assembly 3 during welding, providing a reliable data foundation for the control system, thereby improving the intelligent control level and welding quality of the entire air conditioning compressor casting component welding device.

[0093] like Figure 2 As shown, in a preferred embodiment of the present invention, two rows of conical positioning rollers 2 are provided on both sides of the outer shell 1, with the large end of each conical positioning roller 2 close to the outer shell 1 and the small end away from the outer shell 1.

[0094] In this embodiment, the welding device for the cast components of the air conditioner compressor of this application has its outer shell 1 connected to a horizontal moving mechanism, which is used to support the welding-related components and cooperate in completing the welding operation. To address the problem of unstable positioning and adaptive centering of workpieces with different diameters when welding air conditioner compressor housings, this application provides two rows of conical positioning rollers 2 on both sides of the outer shell 1. These conical positioning rollers 2, through their unique geometry and installation method, work in conjunction with the cast components to be welded.

[0095] Specifically, when the cast air conditioner compressor component to be welded is placed in the welding device, its outer circumference contacts the two rows of conical positioning rollers 2 on both sides of the outer casing 1. Since the larger end of each conical positioning roller 2 is closer to the outer casing 1 and the smaller end is farther away, this means the conical surface of the roller gradually converges outwards. When the workpiece diameter is large, it contacts the larger diameter portion of the conical roller 2 near the larger end; when the workpiece diameter is small, it contacts the smaller diameter portion of the conical roller 2 near the smaller end. Under the influence of gravity, the workpiece automatically slides along the conical surface until its outer circumference forms a stable line or surface contact with the conical surface of the roller, thus achieving automatic centering and positioning of the workpiece. This design allows workpieces of different diameters to be precisely centered and positioned without changing the positioning fixture.

[0096] During the welding process, the horizontal moving mechanism drives the outer shell 1 and the internal composite welding gun assembly 3 to move along the welding direction. The workpiece, supported and limited by the conical positioning rollers 2, maintains its centerline aligned with the welding path and rolls smoothly on the rollers as the welding progresses. This structure ensures the accuracy of the welding path and avoids radial or axial displacement of the workpiece during movement, thus guaranteeing welding quality. Simultaneously, the conical positioning rollers 2 do not obstruct the horizontal movement of the workpiece, meeting the requirements of continuous welding operations.

[0097] In a preferred embodiment of the present invention, the weld pool stability index is calculated in the weld pool condition assessment module as follows: ;

[0098] in The melt pool width deviation index represents the absolute deviation between the current melt pool width and the average width of the previous N cycles. , These are the set lower threshold and upper threshold for molten pool width deviation, respectively;

[0099] This refers to the oscillation frequency at the tail of the molten pool. , These are the set lower threshold and upper threshold for the oscillation frequency, respectively;

[0100] The trailing angle absolute deviation index represents the absolute value of the deviation between the actual trailing angle and the standard value. , These are the set lower limit threshold and upper limit threshold for absolute deviation of trailing angle, respectively;

[0101] This is the weld pool stability index.

[0102] In this embodiment, the weld pool condition assessment module is a functional module used to quantitatively assess the weld pool condition during the welding process. Its concept is to receive raw data from the online detection module and calculate the weld pool stability index according to a preset algorithm. This module can be implemented using hardware platforms such as embedded processors, industrial PCs, or dedicated FPGAs, and run corresponding software algorithms. (Melt pool width deviation index) Used to quantify the degree of fluctuation in the molten pool width, it represents the absolute deviation of the current molten pool width from the average width of the previous N periods.

[0103] The weld pool width can be obtained through real-time image processing of the weld pool image acquired by a coaxial vision sensor. For example, edge detection algorithms can be used to identify the weld pool boundary and calculate its width. The value of N can be set according to welding process requirements and data sampling frequency; for example, N can be 5, 10, or 20. The lower limit threshold for weld pool width deviation is also specified. Upper limit threshold for deviation from molten pool width Used to define the acceptable range of the weld pool width deviation index. These can be preset through experimental testing, expert experience, or numerical simulation, based on specific welding materials, welding process parameters, and desired welding quality standards. Weld pool tail oscillation frequency. Used to characterize the dynamic behavior of the molten pool tail. The oscillation frequency of the molten pool tail can be obtained by performing time-domain analysis on the molten pool image sequence acquired by a coaxial vision sensor, for example, by performing a Fourier transform on the displacement of a specific point at the molten pool tail, or by acquiring acoustic signals during the welding process using an acoustic sensor and performing spectral analysis. Oscillation frequency lower limit threshold. and the upper limit threshold of oscillation frequency These are used to define the normal range of oscillation frequencies at the tail of the molten pool. They can also be set experimentally or empirically based on welding materials, process parameters, and quality requirements.

[0104] absolute deviation index of trailing angle Used to measure the deviation of the molten pool trailing angle. The trailing angle is an important feature of the molten pool morphology and can be measured in real time by performing geometric analysis on the molten pool image acquired by a coaxial vision sensor, for example, fitting the molten pool tail contour line and calculating its angle with the welding direction. Its standard value can be preset according to the molten pool morphology under ideal welding conditions.

[0105] Lower limit threshold of absolute deviation of trailing angle and the upper limit threshold of absolute deviation of trailing angle This is used to define the acceptable range for the absolute deviation of the trailing angle. These ranges can be determined experimentally or through expert experience, based on the welding materials, process parameters, and desired weld formation requirements. The weld pool stability index $S$ is the final quantitative indicator, calculated by multiplying the three normalized terms mentioned above. The index typically ranges from 0 to 1; a higher value indicates better weld pool stability, and vice versa.

[0106] This solution utilizes a weld pool condition assessment module to process real-time data of the molten pool collected from an online detection module (e.g., a coaxial vision sensor) to quantify the stability of the weld pool. Specifically, this module first extracts the molten pool width information from the molten pool image and calculates the absolute deviation of the current molten pool width from the average width of the previous N cycles, thus obtaining the molten pool width deviation index. Simultaneously, it analyzes the dynamic behavior of the molten pool tail to obtain the oscillation frequency at the tail. Furthermore, through geometric analysis of the molten pool morphology, it calculates the absolute deviation index of the trailing angle. Subsequently, these three key indicators—the molten pool width deviation index, the molten pool tail oscillation frequency, and the absolute deviation index of the trailing angle—are compared with preset upper and lower thresholds and normalized to generate three stability components between 0 and 1. These components are combined in a product form to finally obtain the weld pool stability index. This product-based calculation method ensures that a significant deviation in any one of the indicators will lead to a decrease in the overall stability index, thus sensitively reflecting the real-time instability of the weld pool. This solution is closely integrated with the online detection module in the welding device for casting components of air conditioning compressors. The coaxial vision sensor in the online inspection module can acquire molten pool images in real time and coaxially, providing accurate raw data for calculating the molten pool width deviation index and the absolute deviation index of the trailing angle. Simultaneously, the oscillation frequency at the tail of the molten pool can be extracted through analysis of the molten pool image sequence. This synergy between data acquisition and evaluation enables the weld pool condition assessment module to comprehensively and accurately quantify the complex and ever-changing molten pool condition during the welding process of cast components based on multi-dimensional, high-precision real-time data. This overcomes the limitations of traditional single-parameter monitoring and provides a reliable basis for subsequent welding parameter control.

[0107] In a preferred embodiment of the present invention, the comprehensive evaluation index is calculated in the comprehensive evaluation module as follows: ;

[0108] in The coupling coefficient is... , This is the correction factor for the impact of dust. Subtract the measured value of the dust concentration sensor from 1 and divide by the set saturation concentration threshold;

[0109] For the arc length stability component, Subtract the standard deviation of the real-time arc voltage sampling sequence from 1 and divide by (the average value of the real-time arc voltage sampling sequence multiplied by the maximum allowable relative fluctuation under typical process conditions).

[0110] For keyhole stability component, The method is to subtract the standard deviation of the laser back-reflected light intensity sampling sequence from 1, divide by the average value of the laser back-reflected light intensity sampling sequence, and multiply by the maximum allowable relative fluctuation range under typical processes.

[0111] The weld pool stability index, This is a comprehensive evaluation index.

[0112] In this embodiment, the comprehensive evaluation index Q is a key indicator used to quantify the overall stability and quality of the welding process. It is calculated by nonlinearly combining multiple parameters that affect welding quality, and its value directly reflects the quality of the current welding state.

[0113] The weld pool stability index S can be obtained by the weld pool condition assessment module according to a preset calculation method.

[0114] The dust impact correction factor D is used to quantify the negative impact of dust concentration in the welding environment on welding quality. This factor is calculated by comparing the real-time monitored dust concentration with a preset saturation concentration threshold. The closer the value is to 1, the smaller the dust impact and the cleaner the welding environment; conversely, the smaller the value, the greater the dust impact.

[0115] Dust concentration sensors can employ optical scattering principles to acquire real-time dust concentration data by measuring the intensity of light scattering by airborne particles; or they can use piezoelectric crystal microbalance sensors to obtain dust concentration by measuring the frequency changes caused by dust particle deposition on the crystal surface. The arc length stability component A is used to evaluate the stability of the welding arc length.

[0116] Fluctuations in arc length directly affect arc energy density and penetration depth, thus impacting weld quality. This component is calculated through statistical analysis of real-time arc voltage sampling sequences (e.g., the ratio of standard deviation to mean) combined with the maximum permissible relative fluctuation amplitude under typical processes. The arc parameter acquisition unit can employ high-precision voltage sensors and data acquisition cards to acquire arc voltage signals in real time; or it can use Hall effect sensors combined with voltage divider circuits to convert high-voltage arc voltage into measurable low-voltage signals for acquisition.

[0117] The keyhole stability component K is used to evaluate the stability of the keyhole during laser welding. Keyhole stability directly affects the effective coupling of laser energy, penetration depth, and spatter generation. This component is calculated by statistically analyzing the laser back-reflection intensity sampling sequence (e.g., the ratio of standard deviation to mean) and combining it with the maximum permissible relative fluctuation amplitude under typical processes. The laser back-reflection light sensor can employ a photodiode or avalanche photodiode, combined with a narrowband filter, to receive the specific wavelength laser signal reflected from the keyhole; alternatively, a photomultiplier tube can be used to improve the detection sensitivity to weak reflected light.

[0118] The coupling coefficient λ is an adjustable parameter used to adjust the influence weight of cross-coupling terms in the comprehensive evaluation index Q. Its value ranges from 0.05 to 0.35, allowing for flexible adjustment of the degree of mutual influence between different parameters based on specific welding processes and material properties. By adjusting λ, the comprehensive evaluation index Q can better adapt to the welding quality evaluation needs of different application scenarios. The determination of the coupling coefficient λ must comprehensively consider the actual conditions and stability requirements of the welding process. The specific value of this coefficient depends on the degree of coupling between weld pool stability and arc length and keyhole state during the welding process. When the material of the air conditioning compressor casting components is sensitive to heat input fluctuations, and the weld pool stability and arc and keyhole state significantly influence each other during welding, a larger value of λ (e.g., 0.25 to 0.35) is chosen to strengthen the penalty for deviations between weld pool stability and arc length and keyhole state, thereby prioritizing the coordination and consistency among various factors. Conversely, when the welding process is relatively mature, environmental interference is minimal, or dust concentration is high but other factors are stable, a smaller value of λ (e.g., 0.05 to 0.15) is chosen to weaken the correction weight of the coupling term and avoid over-regulation. In practical applications, welding process experiments can be conducted to compare weld formation quality, spatter, and porosity under different λ values, and the λ value that best matches the overall evaluation index with the actual welding effect can be selected.

[0119] The min function is used to find the minimum value in a set of values, and the max function is used to find the maximum value in a set of values. In the calculation of the comprehensive evaluation index Q, they are used to identify the "bottleneck" effect among multiple parameters and to assess the degree of dispersion among the parameters.

[0120] This application's solution addresses the problem of incomplete and insensitive assessment of the impact of multiple factors on welding quality in existing technologies by introducing a nonlinearly coupled comprehensive evaluation index Q. This calculation method organically combines four core parameters: weld pool stability index S, dust influence correction coefficient D, arc length stability component A, and keyhole stability component K. Specifically, this calculation method first... This ensures that the overall evaluation results fully consider the "weakest link" effect among all parameters. This means that even if other parameters perform well, a significant deterioration in just one parameter will greatly affect the overall evaluation index Q, thus avoiding the risk that a severely non-compliant single parameter might still result in an "averaged" pass rating for the overall evaluation, and improving the sensitivity to identifying poor welding conditions. Secondly, through... This section introduces a penalty mechanism for parameter range differences. The greater the difference between these four parameters—that is, the more inconsistent their states—the smaller the value of this section will be, resulting in a penalized reduction in the overall evaluation index Q. This can reflect unfavorable situations of inconsistent multi-parameter states during welding, such as a stable molten pool but drastic arc length fluctuations, or a stable keyhole but excessively high dust concentration, further improving the accuracy of the evaluation. Furthermore, through… The term introduces a cross-coupling penalty adjusted by the coupling coefficient λ. This term reflects the deviation coupling effect between different types of parameters by calculating the product of the absolute value of the deviation between weld pool stability S and arc length stability A, and the absolute value of the deviation between the dust correction coefficient D and keyhole stability K. For example, when there is a large difference between weld pool stability and arc length stability, and also a large difference between dust effect and keyhole stability, this cross-coupling term will significantly reduce the comprehensive evaluation index Q. This further improves the sensitivity of the comprehensive evaluation to the state of multi-factor synergy, enabling the evaluation results to more precisely capture potential problems in complex welding processes. A reasonable range of values ​​for the coupling coefficient λ (0.05 to 0.35) ensures the effective representation of the coupling effect while avoiding excessive influence on the rationality of the final evaluation results. Through the aforementioned nonlinear coupling calculation method, the comprehensive evaluation module can receive real-time data from the online detection module, including the weld pool stability index S provided by the weld pool condition evaluation module, the dust influence correction coefficient D calculated from dust concentration data provided by the dust concentration sensor, the arc length stability component A calculated from arc voltage data provided by the arc parameter acquisition unit, and the keyhole stability component K calculated from laser back-reflection light intensity data provided by the laser back-reflection light sensor. After calculation by the comprehensive evaluation module, this data ultimately outputs a comprehensive evaluation index Q that accurately reflects the actual overall welding condition, providing an accurate and reliable evaluation basis for the subsequent intelligent welding control of the frequency control module and speed control module.

[0121] In a preferred embodiment of the present invention, the frequency optimization calculation method in the frequency control module is as follows: ;

[0122] in Based on the oscillation frequency, For the maximum permissible oscillation frequency, To comprehensively evaluate the index, To optimize the oscillation frequency.

[0123] In this embodiment, the basic oscillation frequency This refers to the preset reference value of the welding torch oscillation frequency under ideal or standard welding process conditions to ensure the stability of the molten pool and the quality of the weld formation. This frequency can be determined experimentally or empirically based on the material, thickness, joint type of the cast component to be welded, and the parameters of the laser-TIG hybrid welding process used. For example, through preliminary process tests, an optimal oscillation frequency can be determined as the base oscillation frequency under stable welding conditions for a specific model of air conditioner compressor cast component. Maximum allowable oscillation frequency. This refers to the highest oscillation frequency achievable while ensuring the normal operation of the welding equipment (especially the piezoelectric ceramic micro-motion oscillation platform 8), preventing overload or resonance of the welding torch oscillation mechanism, and avoiding welding defects. This frequency is typically provided by the equipment manufacturer or determined through equipment performance testing and process window trials. For example, the physical limits of the piezoelectric ceramic micro-motion oscillation platform 8, the response speed of the drive power supply, and the mechanical stability of the welding torch 31 all limit its maximum oscillation frequency. (Comprehensive evaluation index) This index quantifies the overall stability of the current welding process, typically ranging from 0 to 1, with higher values ​​indicating more stable welding conditions. It comprehensively considers multiple factors affecting welding quality, including weld pool stability, dust influence correction coefficient, arc length stability component, and keyhole stability component. For example, when the welding environment has excessively high dust concentration, drastic arc voltage fluctuations, or unstable keyhole stability, the comprehensive evaluation index... The value will decrease, and vice versa. Optimize the oscillation frequency. The frequency control module uses a comprehensive evaluation index based on the current welding process. The optimal welding torch oscillation frequency, calculated in real-time using a specific formula, is best suited to the current welding condition. This frequency aims to maintain or improve the stability of the molten pool by dynamically adjusting the torch oscillation, thereby enhancing weld quality. For example, when the comprehensive evaluation index... Optimize oscillation frequency at lower levels This will be increased accordingly to enhance molten pool stirring, promote gas escape, and stabilize the welding process.

[0124] The solution proposed in this application introduces a comprehensive evaluation index. This system achieves adaptive optimization and control of the oscillation frequency of the composite welding torch assembly 3. Specifically, the online detection module (including a coaxial vision sensor, dust concentration sensor, infrared thermal imager, arc parameter acquisition unit, and laser back-reflection light sensor, etc.) collects multi-dimensional data during the welding process in real time, and this data is transmitted to the control system. The weld pool condition assessment module in the control system first outputs the weld pool stability index based on the weld pool width fluctuation rate, weld pool tail oscillation frequency, and trailing angle deviation. Subsequently, the comprehensive assessment module further performs nonlinear coupling calculations on the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component to output a comprehensive assessment index. This comprehensive evaluation index It can comprehensively and accurately reflect the overall stability under the coupled effects of multiple factors in the current welding process. Based on this, the frequency control module receives the comprehensive evaluation index Q and combines it with the preset basic oscillation frequency. and maximum permissible oscillation frequency According to the formula Calculate the optimal oscillation frequency The calculation logic cleverly incorporates the comprehensive evaluation index. This is related to the adjustment amount of the oscillation frequency: when When the value is low (indicating an unstable welding condition), A larger value makes optimizing the oscillation frequency easier. Relative to the fundamental oscillation frequency There is a greater improvement, thereby improving stability by enhancing molten pool stirring; conversely, when A higher value (indicating a stable welding condition) The value is small. Closer This avoids unnecessary frequency adjustments. The calculated optimized oscillation frequency f_opt is then sent to the piezoelectric ceramic micro-oscillation platform 8, which drives the coaxial composite welding torch 31 to oscillate at the corresponding frequency. This is based on a comprehensive evaluation index. The frequency control mechanism transforms the adjustment of the oscillation frequency from a simple feedback of a single parameter into an intelligent response to the overall welding state. It fully utilizes multi-source information provided by the online detection module and deeply integrates this information through a comprehensive evaluation module, thus providing precise decision-making basis for frequency control. This synergistic effect ensures that the oscillation frequency of the welding torch remains optimal during the complex and variable welding process of cast components, effectively suppressing defects such as molten pool instability, porosity, and cracks, significantly improving welding quality and stability. Simultaneously, this optimized oscillation frequency also provides an accurate parameter basis for the subsequent speed control module to perform collaborative optimization of the movement speed, further improving the intelligent control of the entire welding process.

[0125] In a preferred embodiment of the present invention, the calculation method for optimizing the movement speed in the speed control module is as follows: ;

[0126] in Based on movement speed, The sensitivity coefficient of velocity to oscillation frequency. , To comprehensively evaluate the index, Based on the oscillation frequency, To set the optimal oscillation frequency, To optimize movement speed.

[0127] In this embodiment, the base moving speed This is the initial moving speed pre-set based on the material, thickness, joint type, and predetermined welding process parameters (such as laser power, arc current, and gas flow rate) of the cast components of the air conditioning compressor to be welded. This setting can be determined by consulting process manuals, calculating using empirical formulas, or conducting welding experiments. As a benchmark for calculating the optimized moving speed, it ensures that the final optimized moving speed always remains within a reasonable process range, preventing the optimization result from deviating from actual production requirements.

[0128] Sensitivity coefficient of velocity to oscillation frequency This is a parameter characterizing the degree to which the moving speed responds to changes in the oscillation frequency. The value of this coefficient ranges from 0.1 to 0.5. Its specific value can be determined through experimental calibration, numerical simulation, or expert experience, depending on the type and thickness of the welding material, the type of weld joint, and the welding process requirements. For example, for certain materials or processes that are more sensitive to changes in oscillation frequency, a higher value can be set. A value can be set to make the movement speed respond more significantly to adjustments in the oscillation frequency; conversely, a lower value can be set. value.

[0129] Comprehensive evaluation index This is a quantitative index reflecting the overall state of the current welding process. It comprehensively considers multiple key parameters, including the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component, and is calculated through nonlinear coupling. A higher value indicates a more stable and ideal welding state. This index provides a comprehensive basis for subsequent welding parameter optimization. (Basic oscillation frequency) This is the initial oscillation frequency preset based on welding process requirements and experience. It is typically a reference value determined under stable welding conditions for a specific material and joint type. This frequency can be set based on factors such as the weld penetration requirements, weld width control, and weld formation, for example, by consulting process specifications or conducting preliminary tests. Setting the optimal oscillation frequency... This is the optimized oscillation frequency calculated by the frequency control module based on the comprehensive evaluation index and the current oscillation frequency of the composite welding torch assembly 3. This frequency is adjusted in real time to achieve the best oscillation effect in the current comprehensive state of the welding process, thereby improving weld quality and stability. Maximum allowable oscillation frequency. The upper limit of the oscillation frequency is set based on the mechanical properties of the composite welding torch assembly 3, the welding process window, and the limitations of avoiding welding defects (such as spatter, undercut, etc.). This value ensures that the adjustment of the oscillation frequency does not exceed the range that the equipment and process can withstand, thereby guaranteeing the safety and stability of the welding process.

[0130] The solution in this application uses a speed control module based on a comprehensive evaluation index. And setting the optimal oscillation frequency This approach adaptively adjusts the movement speed to achieve coordinated optimization between the swing frequency and movement speed. Specifically, the scheme uses a base movement speed... As a calculation benchmark, this base moving speed is an initial value preset based on the material of the air conditioner compressor casting component to be welded and the established welding process, ensuring that the optimized moving speed always remains within a reasonable process range. Based on this, the moving speed is further optimized. Calculation and comprehensive evaluation index Directly related, comprehensive evaluation index It is a parameter reflecting the overall state of the current welding process, obtained by combining multiple dimensions such as weld pool stability, dust influence, arc length stability, and keyhole stability. As the numerator of the calculation formula, the optimized moving speed can be dynamically adjusted according to the current overall welding condition; that is, the better the overall welding condition, the better the speed. The higher the value, the better the optimized movement speed can adapt to the needs of the current state, realizing the adaptive adjustment of the movement speed according to the actual welding state and ensuring the rationality of the movement speed adjustment.

[0131] Furthermore, the denominator of this calculation formula introduces a correction term based on the adjustment amplitude of the oscillation frequency. This correction term is determined by setting the optimal oscillation frequency. With the fundamental oscillation frequency The difference, and the maximum permissible oscillation frequency. With the fundamental oscillation frequency The ratio of the differences quantifies the adjustment range of the current oscillation frequency relative to the initial base oscillation frequency. Simultaneously, a pre-set sensitivity coefficient for the oscillation frequency is introduced. This coefficient characterizes the degree to which changes in oscillation frequency affect the moving speed. By incorporating the optimized oscillation frequency into the calculation of the moving speed, this scheme enables the moving speed to be correspondingly corrected and adapted after the oscillation frequency is adjusted, thus achieving the coordinated optimization of two key welding parameters—oscillation frequency and moving speed. This coordinated mechanism avoids the instability problems that may arise from traditional single-parameter adjustments. For example, when the oscillation frequency changes but the moving speed fails to adjust synchronously, it may lead to unstable molten pool morphology or poor weld formation. Through this coordinated adjustment, this scheme significantly improves the overall stability of the welding process and ultimately ensures that the welding quality meets the requirements.

[0132] like Figure 6 As shown, as a preferred embodiment of the present invention, a welding method for casting components of an air conditioning compressor, applied to any of the above-described devices, includes the following steps:

[0133] S1: Place the air conditioner compressor casting component to be welded inside the housing, and move the housing through the horizontal moving mechanism to align the weld seam with the composite welding gun assembly;

[0134] S2: Real-time acquisition of weld pool status, dust concentration inside the shell, and status parameters of the composite welding gun assembly during welding via online detection module;

[0135] S3: The weld pool condition assessment module in the control system outputs the weld pool stability index based on the weld pool width fluctuation rate, weld pool tail oscillation frequency and trailing angle deviation.

[0136] S4: The comprehensive evaluation module in the control system outputs a comprehensive evaluation index based on the weld pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component.

[0137] S5: The frequency control module in the control system outputs an optimized frequency based on the comprehensive evaluation index and the current oscillation frequency of the composite welding gun assembly.

[0138] S6: The speed control module in the control system outputs the optimized movement speed based on the optimized frequency, comprehensive evaluation index, and the current movement speed of the composite welding gun assembly.

[0139] S7: Control the piezoelectric ceramic micro-motion swing platform 8 and the horizontal movement mechanism according to the optimized frequency and optimized moving speed respectively.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding device for casting components of an air conditioning compressor, comprising a housing (1), the housing (1) being connected to a horizontal moving mechanism, and two infrared quartz radiation plates (6) being disposed at opposite positions on the inner sidewall of the housing (1). The composite welding torch assembly (3) includes a coaxial composite welding torch (31) and an annular TIG arc nozzle (32). The coaxial composite welding torch (31) has a central laser beam channel, and the annular TIG arc nozzle (32) is arranged around the central laser beam channel. The coaxial composite welding torch (31) is connected to the top of the housing (1) through a piezoelectric ceramic micro-motion oscillation platform (8). An elastic corrugated sealing sleeve (5) is connected between the piezoelectric ceramic micro-motion oscillation platform (8) and the top of the housing (1). The annular TIG arc nozzle (32) extends into the interior of the housing (1) through the top wall of the housing (1). A high-temperature resistant metal wire brush (7) is set at the bottom front side of the housing (1), and a dust removal component (4) is provided inside the housing (1). The online detection module is used to collect the molten pool status, dust concentration in the shell (1), and status parameters of the composite welding gun assembly (3) during welding; It also includes a control system, connected to the online detection module, which includes: The molten pool condition assessment module is used to output the molten pool stability index based on the molten pool width deviation index, the molten pool tail oscillation frequency, and the absolute deviation index of the trailing angle. The comprehensive evaluation module is used to output a comprehensive evaluation index based on the molten pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component. The frequency control module is used to optimize the oscillation frequency based on the comprehensive evaluation index and the current oscillation frequency output of the composite welding gun assembly (3); The speed control module is used to optimize the moving speed based on the optimized oscillation frequency, the comprehensive evaluation index and the current moving speed output of the composite welding gun assembly (3); In the molten pool condition assessment module, the molten pool stability index is obtained in the following way: ； in This refers to the molten pool width deviation index; , These are the set lower threshold and upper threshold for molten pool width deviation, respectively; This refers to the oscillation frequency at the tail of the molten pool. , These are the set lower threshold and upper threshold for the oscillation frequency, respectively; The absolute deviation index of the trailing angle. , These are the set lower limit threshold and upper limit threshold for absolute deviation of trailing angle, respectively; This refers to the molten pool stability index. In the comprehensive evaluation module, the comprehensive evaluation index is obtained in the following ways: ； in The coupling coefficient is... , This is the correction factor for the impact of dust. Subtract the measured value of the dust concentration sensor from 1 and divide by the set saturation concentration threshold; For the arc length stability component, It equals 1 minus the relative fluctuation amplitude of the arc voltage divided by the maximum allowable relative fluctuation amplitude under typical processes; the relative fluctuation amplitude of the arc voltage is: the standard deviation of the real-time sampling sequence of the arc voltage divided by the average value of the real-time sampling sequence of the arc voltage. For keyhole stability component, It equals 1 minus the relative fluctuation range of the laser back-reflected light intensity divided by the maximum allowable relative fluctuation range under typical processes; the relative fluctuation range of the laser back-reflected light intensity is: the standard deviation of the laser back-reflected light intensity sampling sequence divided by the average value of the laser back-reflected light intensity sampling sequence; For comprehensive evaluation index; In the frequency control module, the optimized oscillation frequency is obtained through the following methods: ； in Based on the oscillation frequency, For the maximum permissible oscillation frequency, To optimize the oscillation frequency; In the speed control module, optimized movement speed is obtained through the following methods: ； in Based on movement speed, The sensitivity coefficient of velocity to oscillation frequency. , To optimize movement speed.

2. The apparatus according to claim 1, characterized in that, The online detection module includes a coaxial vision sensor, a dust concentration sensor, an infrared thermal imager, an arc parameter acquisition unit, and a laser back-reflection light sensor. The coaxial vision sensor is installed on the outside of the central laser beam channel of the coaxial composite welding torch (31) and acquires the molten pool image coaxially with the laser beam. The infrared thermal imager is installed on the inner wall of the outer shell (1) and is used to acquire the two-dimensional temperature field distribution of the weld zone. The arc parameter acquisition unit is connected to the welding power supply of the annular TIG arc nozzle (32) and is used to acquire the arc voltage in real time. The laser back-reflection light sensor is coupled to the outside of the central laser beam channel through a beam splitter and is used to acquire the intensity of the laser signal reflected back from the keyhole of the molten pool in real time.

3. The apparatus according to claim 1, characterized in that, The infrared quartz radiation plates (6) are all independently controlled by a programmable temperature field controller, which is used to perform gradient preheating and slow cooling after welding at the weld position. The programmable temperature field controller stores a nonlinear temperature curve corresponding to the material of the cast component. The curve forms a preheating zone, a constant temperature welding zone and a slow cooling zone along the welding direction. The temperature of the slow cooling zone drops in a stepwise manner to below the welding crack sensitive temperature threshold corresponding to the material.

4. The apparatus according to claim 1, characterized in that, The dust removal assembly (4) includes a flow guide baffle (41), which is located at the top of the inner side of the housing (1). A filter box (42) and an air pump (43) are arranged above the flow guide baffle (41).

5. The apparatus according to claim 1, characterized in that, A row of conical positioning rollers (2) is provided on each side of the outer shell (1), with the large end of each conical positioning roller (2) close to the outer shell (1) and the small end away from the outer shell (1).

6. A welding method for cast components of an air conditioning compressor, using the apparatus described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Place the air conditioner compressor casting component to be welded inside the housing (1), and move the housing (1) through the horizontal moving mechanism so that the weld seam is aligned with the composite welding gun assembly (3). S2: Real-time acquisition of molten pool status, dust concentration inside shell (1), and status parameters of composite welding gun assembly (3) during welding through online detection module; S3: The molten pool condition assessment module in the control system outputs the molten pool stability index based on the molten pool width deviation index, the molten pool tail oscillation frequency, and the absolute deviation index of the trailing angle. S4: The comprehensive evaluation module in the control system outputs a comprehensive evaluation index based on the molten pool stability index, dust influence correction coefficient, arc length stability component, and keyhole stability component. S5: The frequency control module in the control system optimizes the swing frequency based on the comprehensive evaluation index and the current swing frequency output of the composite welding gun assembly (3); S6: The speed control module in the control system optimizes the moving speed based on the optimized oscillation frequency, comprehensive evaluation index and the current moving speed output of the composite welding gun assembly (3); S7: Control the piezoelectric ceramic micro-motion oscillation platform (8) and the horizontal movement mechanism according to the optimized oscillation frequency and optimized movement speed respectively.

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