Multi-station timing cleaning system and method for air conditioner muffler

Abstract

The application relates to a multi-station timing cleaning system and method for an air conditioner silencer, which comprises six groups of processing tank bodies arranged in a straight line in sequence, a timing coordinated flow transfer crane, a tail-end foolproof perception unloading unit and a main control system. The six groups of processing tank bodies constitute three processing sections of ultrasonic degreasing, normal-temperature water passing and rust prevention and constant-temperature closed drying. The timing coordinated flow transfer crane cross-carrying baskets with two hook assemblies. The tail-end foolproof perception unloading unit releases workpieces when the receiving trolley is in place. The main control system coordinates the timing flow transfer of the baskets between the processing tank bodies, so that the deep-cavity silencer can realize cleaning, drying and reliable unloading in continuous unmanned flow transfer.

Description

Technical Field

[0001] This application relates to the field of metal cleaning equipment, and in particular to a multi-station sequential cleaning system and method for air conditioner mufflers. Background Technology

[0002] An air conditioner muffler is a sheet metal component in an air conditioning system used to reduce refrigerant flow noise. It has a deep cavity structure formed by multiple layers of bending. During the mass production of mufflers, the sheet metal forming and machining processes can leave cutting fluid and oil residue on the workpiece surface, and metal debris can accumulate in the deep cavities. To ensure the muffler meets assembly and usage requirements, it needs to be cleaned after forming and before assembly to remove surface cutting fluid and oil residue and flush out metal debris from the deep cavities. Following this, rust prevention and drying treatments are performed.

[0003] The deep cavity structure of the muffler makes cleaning and drying more difficult than for ordinary flat sheet metal parts. Cutting fluid and debris can easily get trapped in the bends and blind spots of the deep cavity, and residual moisture in the deep cavity is not easily evaporated during drying. If cleaning or drying is not thorough, residual cutting fluid will corrode the workpiece during subsequent storage and transportation, water accumulated in the deep cavity will seep out after assembly, and metal debris mixed into the refrigeration system will cause blockages and abnormal noises. To meet large-scale production capacity, the cleaning operation needs to be composed of multiple processing stations forming a continuous production line, and manual supervision should be minimized.

[0004] Existing multi-station cleaning production lines typically use a single transport mechanism driven by a fixed cycle time to sequentially move workpieces between processing tanks, completing the processing and final drying of each tank within a fixed time. Loading and unloading are based on a simple determination of whether a workpiece is present at the station. Because each processing station operates independently and in an open-loop manner, these production lines cannot adjust to the real-time status of the deep cavity silencer during degreasing, rust prevention, drying, and unloading. Consequently, workpieces are still removed at fixed times before the residual liquid in the deep cavity has completely evaporated, and release is still performed when there is no receiving device at the end. Furthermore, it is difficult to increase the cycle time when the single transport mechanism moves back and forth in sequence, making it difficult to achieve both continuous unmanned operation and reliable results for each processing stage. Summary of the Invention

[0005] In order to ensure reliable results in each processing stage during the continuous unmanned cleaning process of deep cavity mufflers, this application provides a multi-station sequential cleaning system and method for air conditioning mufflers.

[0006] Firstly, this application provides a multi-station sequential cleaning system for air conditioner mufflers, which adopts the following technical solution: A multi-station sequential cleaning system for air conditioner mufflers includes six sets of processing tanks arranged in a straight line. Each set of tanks includes an ultrasonic degreasing unit, a room-temperature water rinsing and rust prevention unit, and a constant-temperature closed drying unit. The ultrasonic degreasing unit includes a first tank and a second tank, each equipped with an ultrasonic generator array. The room-temperature water rinsing and rust prevention unit includes a third tank serving as a clean water overflow tank and a fourth tank serving as a rust-preventing liquid tank. The constant-temperature closed drying unit includes a fifth tank and a sixth tank, each with a sliding cover and a heating module. When the sliding cover is closed, it forms a closed cavity with the corresponding tank. The heating module is configured to operate at the drying temperature. A sequentially coordinated conveyor crane includes a main crossbeam extending along the arrangement direction of the six sets of processing tanks and a suspension system. The first and second hook assemblies on the main crossbeam are configured to cross-coordinately carry the basket containing the muffler and allow the basket to move between the six sets of processing tanks; the end-of-line foolproof sensing unloading unit is located in the unloading area downstream of the constant temperature closed drying unit, including a distance sensor and a release actuator. The distance sensor is configured to detect the receiving car in the unloading area, and the release actuator is configured to unlock when the receiving car is in place to release the muffler in the basket to the receiving car; the main control system is connected to the ultrasonic generator array, heating module, time-coordinated flow crane, sliding cover, distance sensor and release actuator, and is configured to coordinate the time-coordinated flow of the basket between the six sets of processing tanks.

[0007] By adopting the above technical solution, the three processing sections of degreasing, water rinsing for rust prevention, and closed drying are arranged sequentially along a straight line and uniformly scheduled by the main control system. This allows the deep cavity silencer to complete the removal of cutting fluid and debris, rust prevention, and deep cavity drying sequentially on the same production line. The time-coordinated transfer crane uses two hook components to cross-coordinate the transport of baskets, so that while the previous basket is still being processed in a certain processing tank, the next basket can already be transferred to the adjacent tank, thereby increasing the turnover rate without increasing the number of transport mechanisms. The end-of-line foolproof sensing unloading unit releases the workpiece only after confirming that the receiving car is in place, preventing the unloading link in continuous flow from falling due to lack of a receiver. The status of each processing unit, transfer crane, and unloading unit is integrated into the closed-loop coordination of the main control system, ensuring the reliability of each process in the continuous unmanned flow of the deep cavity silencer.

[0008] Optionally, the distance sensor is configured to detect the presence, alignment, and full load status of the receiving car, and the release actuator is configured to unlock only when the receiving car is in place, aligned, and not fully loaded.

[0009] By adopting the above technical solution, the judgment before unloading is expanded from a single "whether to receive" to three dimensions: in place, aligned, and fully loaded. This ensures that the workpiece is released only when the receiving device is in place and aligned, and there is still room to accommodate it, thereby reducing misalignment, falling, and stacking compression.

[0010] Optionally, the end-of-line foolproof sensing unloading unit also includes a hardware interlocking element connected in series in the unlocking circuit of the release actuator. The hardware interlocking element is configured to lock the release actuator to the non-release side in a fail-safe manner and trigger an audible and visual alarm when the feedback from the distance sensor is missing or abnormal.

[0011] By adopting the above technical solution, when the distance sensor loses effective feedback due to water mist, the release action is locked to the non-release side by hardware interlock, so that the sensor failure is transformed into a stop rather than accidental release.

[0012] Optionally, the main control system is configured to respond to the basket's hovering time in the unloading area exceeding a preset time threshold, control the timing coordination crane to retract the basket to one of the emptied drying tanks in the fifth and sixth slots, and make the heating module of the drying tank operate at a drying temperature lower than the drying temperature.

[0013] By adopting the above technical solution, when the material cannot be finished for a long time, the basket is returned to the empty drying tank and dried at low temperature, so that the waiting deep cavity workpieces will not rust in the water mist environment of the workshop, and the end hook is freed up to resume circulation.

[0014] Optionally, the constant temperature closed drying unit also includes a humidity detection element for detecting the humidity of the air venting the closed chamber. The main control system is configured to determine the drying endpoint based on the air venting humidity and stop heating the closed chamber accordingly.

[0015] By adopting the above technical solution, the change in humidity of the air venting the sealed cavity is used to determine whether the moisture in the deep cavity has been completely evaporated, so that the drying endpoint is determined by the actual drying state of the workpiece, rather than a fixed drying time.

[0016] Optionally, the constant temperature closed drying unit also includes a detection element for detecting when the sliding cover is closed. The main control system is configured to temporarily suspend the heating module at the drying temperature in response to when the sliding cover is not closed, and then activate the drying endpoint determination based on the humidity of the exhaust air after the sliding cover is closed.

[0017] By adopting the above technical solution, the temperature rise is temporarily slowed down when the cover is not completely closed, so that the humidity criterion of the sealed cavity is established on the premise that the airtightness is achieved, thus avoiding misjudgment of the drying end point and energy loss caused by heat leakage.

[0018] Optionally, the main control system is configured to perform interlock handshake control when the first hook assembly and the second hook assembly hand over the basket at the handover position, so that the hook assembly that arrives at the handover position first locks the basket before the other hook assembly releases the basket, and the basket is always held by at least one of the first hook assembly and the second hook assembly during the handover process.

[0019] By adopting the above technical solution, the two hook components work together in a lock-then-release handshake sequence when handing over the basket, so that the basket is always held by at least one hook throughout the handover process, avoiding falling off and collision during cross-cooperative handling.

[0020] Optionally, the main control system is configured to control the timing-coordinated flow of the crane, so that after the basket is lifted from the current processing tank, it is suspended above the current processing tank for a preset draining time, and then transferred to the processing tank adjacent to the current processing tank.

[0021] By adopting the above technical solution, after leaving one treatment tank, the basket is suspended above the original tank to drain the liquid before being transferred to the next tank, so that the attached treatment liquid drips back into the original tank, reducing cross-contamination caused by the treatment liquid being carried into adjacent tanks.

[0022] Optionally, the ultrasonic degreasing unit also includes a water quality detection element for detecting the turbidity or conductivity of the cleaning fluid in the tank. The main control system is configured to infer the amount of residual contamination in the silencer in the basket based on the turbidity or conductivity, and adjust the degreasing rhythm of the basket in the ultrasonic degreasing unit accordingly.

[0023] By adopting the above technical solution, the degree of contamination of the incoming workpiece can be inferred from the turbidity or conductivity of the cleaning solution in the degreasing tank, so that the heavily contaminated workpiece can obtain a longer degreasing time, while the lightly contaminated workpiece is not over-processed.

[0024] Optionally, the first hook assembly and the second hook assembly share the main crossbeam. The main control system is configured to maintain the distance between the first hook assembly and the second hook assembly on the main crossbeam at no less than a preset safety distance, and in response to the intersection of the flow paths of the first hook assembly and the second hook assembly, control one of the hook assemblies to retreat to the avoidance position and resume flow after the other hook assembly has passed.

[0025] By adopting the above technical solution, the two hook assemblies maintain a safe distance on the shared main beam, and when the flow paths intersect, one of them is made to back away to give way, so that the two hooks do not collide with each other on the beam during cross-cooperative handling.

[0026] Optionally, the end-of-line foolproof sensing unloading unit also includes a mechanical contact confirmation element arranged in parallel with the distance sensor. The main control system is configured to use the confirmation result of the mechanical contact confirmation element as the unlocking criterion for releasing the actuator when the feedback from the distance sensor is missing.

[0027] By adopting the above technical solution, mechanical contact confirmation is used as the basis for unlocking when the distance sensor fails, providing an independent backup sensing for gate control judgment.

[0028] Optionally, the main control system is configured to respond in stages based on the duration of the basket's hovering in the unloading area. When the hovering time is within the first time threshold, the basket remains hovered; when the hovering time exceeds the first time threshold, the basket is reversed for drying; and when the hovering time exceeds the second time threshold, the cycle time is reduced and an audible and visual alarm is activated.

[0029] By adopting the above technical solution, progressive measures such as hovering, retraction drying, and speed reduction alarm are taken according to the hovering duration, so that the response to abnormal material feeding is matched with the duration.

[0030] Optionally, the main control system is configured to, after the baskets have been returned to the drying trough for drying, control the timing coordination of the crane to allow the freed-up hook assembly to carry the remaining baskets for continued circulation.

[0031] By adopting the above technical solution, after the basket is retracted and dried, its hook is freed up for transporting the remaining baskets, so that the material discharge is not blocked but the flow of the upstream troughs is not interrupted.

[0032] Optionally, the main control system is configured to determine that the drying endpoint has been reached when the rate of decrease in the outlet humidity is lower than a preset rate, or when the outlet humidity remains lower than the preset humidity for a duration exceeding a preset holding time.

[0033] By adopting the above technical solution, the rate of humidity decrease or the duration of sustained low humidity is used as the endpoint criterion to adapt to the differences in humidity curve shape under different loading conditions.

[0034] Optionally, the main control system is configured to maintain the heating module in operation for a preset re-inspection time and re-measure the humidity of the air in the sealed cavity after determining that the drying endpoint has been reached. In response to the rise in the re-measured humidity of the air, the constant temperature sealed drying is extended.

[0035] By adopting the above technical solution, after determining the endpoint, the humidity is measured again while maintaining the temperature, so that individual deep cavities that are lagging in drying can be supplemented with drying when the humidity rises.

[0036] Optionally, the arrival detection element can be a limit switch located at the end of the sliding cover's travel, or a pressure detection element that detects the sealing pressure of the sliding cover.

[0037] By adopting the above technical solution, the door is confirmed to be in place by limit switch or sealing pressure detection, providing a specific detection method for the sealing of the closed cavity.

[0038] Optionally, the interlock handshake control causes the hook assembly that arrives at the handover position first to send a takeover permission signal to another hook assembly after locking the handover position, and the other hook assembly releases the basket in response to the takeover permission signal.

[0039] By adopting the above technical solution, the takeover signal is allowed to trigger the release of another hook, so that the handshake handover is driven by the signal rather than time estimation.

[0040] Optionally, the main control system is configured to set the draining time of the suspended draining based on the type of liquid contained in the adjacent treatment tanks.

[0041] By adopting the above technical solution, the drainage time is set according to the type of liquid in adjacent tanks, so that the treatment liquid with higher viscosity can obtain a longer drainage time.

[0042] Optionally, the main control system is configured to extend the degreasing cycle of the basket in the ultrasonic degreasing unit according to the amount of residual contamination; the greater the amount of residual contamination, the longer the degreasing cycle.

[0043] By adopting the above technical solution, the degreasing time is extended according to the amount of residual pollution, so that the degreasing treatment intensity increases with the degree of pollution of the incoming material.

[0044] Optionally, the main control system is configured to look up a table based on the model of the silencer in the basket to set the degreasing rhythm of the basket in the ultrasonic degreasing unit.

[0045] By adopting the above technical solution, the degreasing cycle can be set by referring to a table according to the muffler model, and the corresponding processing time can be preset for workpieces with different structures.

[0046] Optionally, the main control system is configured to respond to the extension of the drying time of the constant temperature closed drying unit, or the retraction of the basket to occupy one of the drying tanks in the constant temperature closed drying unit, thereby reducing the cycle time of the upstream ultrasonic degreasing unit and the ambient temperature water rinsing and rust prevention unit.

[0047] By adopting the above technical solution, when the drying section becomes a bottleneck or a drying tank is occupied, the upstream feeding cycle can be reduced, so that the number of work-in-process in each tank matches the processing capacity.

[0048] Optionally, the room temperature water rinsing and rust prevention unit also includes a concentration detection element for detecting the concentration of the rust prevention solution in the rust prevention solution tank, and the main control system is configured to replenish the rust prevention solution tank with rust prevention concentrate in response to the rust prevention solution concentration being lower than a preset concentration.

[0049] By adopting the above technical solution, when the concentration of the rust inhibitor decreases due to consumption, the concentrate is added to maintain the rust prevention effect at the preset level.

[0050] Optionally, the constant temperature closed drying unit is equipped with a waste heat recovery channel that directs the waste heat discharged from the heating module to the ultrasonic degreasing unit.

[0051] By adopting the above technical solution, the waste heat of the drying section is directed to the degreasing section to preheat the degreasing tank liquid, thereby reducing heating energy consumption.

[0052] Optionally, the time-coordinated crane is equipped with a positioning detection element to detect the positioning status of the basket, and the main control system is configured to control the system to stop and alarm in response to the basket not being in place or being stuck.

[0053] By adopting the above technical solution, the machine will stop and alarm when the basket is not in place or gets stuck, thus preventing the handling mechanism from continuing to operate under abnormal conditions and causing damage.

[0054] Optionally, the ultrasonic generator array is configured to be excited in a frequency sweep mode or a partitioned alternating mode.

[0055] By adopting the above technical solutions, ultrasound can be excited in a frequency sweeping or partitioned alternating manner, thereby reducing the standing wave blind zone of the sound field at a fixed frequency.

[0056] Optionally, the distance sensor is a photoelectric sensor.

[0057] By adopting the above technical solution, non-contact detection of the receiving car in the unloading area is achieved using photoelectric sensors.

[0058] Optionally, the main control system is configured to continue carrying the basket between the six processing tanks in response to a failure of one of the first hook assembly and the second hook assembly, with the other hook assembly degraded to a single hook.

[0059] By adopting the above technical solution, when one hook assembly fails, the other hook can be degraded to a single hook operation, so that the handling process can be completed without the entire production line being shut down, even if the cycle time is sacrificed.

[0060] Optionally, the main control system is configured to, based on the cumulative trend of turbidity or conductivity measured by the water quality detection element, trigger the replenishment or replacement of the cleaning fluid in the ultrasonic degreasing unit and suspend the upstream feed when the accumulated pollution exceeds a preset threshold.

[0061] By adopting the above technical solution, the degreasing tank solution is changed according to the trend of accumulated pollution and the feeding is temporarily suspended, so that the degreasing efficiency does not decrease due to tank saturation.

[0062] Optionally, the main control system is configured to record the drying curve of the humidity of the air vent in the sealed chamber over time, and in response to the time taken to reach the drying endpoint exceeding a preset time, extend the preset time for constant temperature sealed drying of subsequent batches and issue a prompt to reduce the loading amount.

[0063] By adopting the above technical solution, the drying preset of subsequent batches is adjusted according to the abnormal drying time of the drying curve and a prompt is given to reduce the load, so that the drying parameters can adapt to the loading conditions.

[0064] Optionally, the main control system is configured to respond to a fully loaded receiving car by issuing an empty car dispatch request and retracting the subsequent baskets to the fifth or sixth drying tank, and then resuming release once the empty receiving car is in place.

[0065] By adopting the above technical solution, empty cars are dispatched when the receiving car is fully loaded and the subsequent baskets are returned for drying, so that the upstream flow is not interrupted during the replacement of material receiving.

[0066] Secondly, this application provides a multi-station sequential cleaning method for air conditioner mufflers, which adopts the following technical solution: A multi-station sequential cleaning method for air conditioner mufflers is applied to a cleaning system. The cleaning system includes six sets of processing tanks arranged in a straight line, a sequentially coordinated rotating crane with a first hook assembly and a second hook assembly, and a distance sensor located in the end unloading area. The first and second tanks of the six sets of processing tanks constitute an ultrasonic degreasing unit, the third tank is a clean water overflow tank, the fourth tank is a rust-preventive liquid tank, and the fifth and sixth tanks each have sliding covers that form a closed cavity when the sliding covers are closed. The method includes: S1. Control the timing and coordinate the flow of the crane to sink the basket containing the silencer into the first and second tanks, and perform ultrasonic degreasing on the silencer in the basket; S2. After rinsing the basket with clean water in the third tank, transfer it to the fourth tank for immersion in rust-preventive solution, and suspend the basket to drain the solution before transferring it to the adjacent treatment tank. S3. In response to the basket being moved to the top of the fifth or sixth slot, the sliding cover door under the basket is triggered to open. After the basket descends and enters, the sliding cover door is closed to form a closed cavity, and the closed cavity is heated to dry the silencer. S4. Move the dried basket to the unloading area. In response to the distance sensor detecting that the receiving car is in place, aligned and not fully loaded, unlock and release the muffler to the receiving car. In response to the receiving car not being in place, lock without releasing. In response to the basket hovering in the unloading area for a timeout, return the basket to one of the fifth or sixth slots that is already empty for drying.

[0067] By adopting the above technical solution, degreasing, water rinsing for rust prevention, and closed drying are applied sequentially to the deep cavity silencer on the same production line in the order of S1 to S3, so that the removal of cutting fluid and debris, rust prevention, and deep cavity drying are completed in continuous operation. In S2, water rinsing and suspension draining are used to connect degreasing and rust prevention, reducing the amount of treatment fluid carried over to other tanks. In S3, the closed cover forms a closed cavity for reheating, allowing the moisture in the deep cavity to evaporate in a sealed environment. In S4, the presence, alignment, and full load of the receiving car are used as release conditions, and the basket that has been suspended for too long is returned for drying, so that the unloading process will not fall or rust back when there is a lack of receiving or a long waiting time. Thus, the reliable results of each processing stage are taken into account in continuous unmanned operation.

[0068] In summary, this application includes at least one of the following beneficial technical effects: 1. The three sections of degreasing, water rinsing for rust prevention, and closed drying are arranged in a straight line and scheduled in a unified time by the main control system. With the cross-cooperative handling of the two hook components and the sensing gate control of the end receiving car, the deep cavity silencer can complete thorough cleaning, rust prevention and deep cavity drying in continuous unmanned operation, and avoid falling when there is no support during the unloading process.

[0069] 2. The drying endpoint is determined by the humidity of the air vent in the closed chamber; the degreasing cycle is adjusted by back-calculating the amount of contamination in the incoming material using the turbidity or conductivity of the degreasing tank liquid; cross-contamination between tanks is reduced by using suspended draining; and the closed chamber is sealed by using door positioning detection. This allows the intensity and duration of each processing step to be adjusted as needed according to the actual condition of the workpiece, rather than using a fixed-time open-loop process.

[0070] 3. By using the safe distance and cross-gap between the two hook assemblies on the shared main beam to avoid mutual collision, by using the single hook failure degradation to maintain the flow, and by using the suspension timeout to return to the drying tank for drying and hook reuse, the continuous flow can still maintain operation under abnormal conditions such as handling conflicts, local failures and material obstruction, so as not to cause the entire line to stop production or workpieces to rust. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the overall structure of a multi-station sequential cleaning system for air conditioner mufflers in one embodiment of this application.

[0072] Figure 2 This is a schematic diagram of the structure of a constant temperature sealed drying unit in one embodiment of this application.

[0073] Figure 3 This is a schematic diagram of the end-effector error-proof sensing and unloading unit in one embodiment of this application.

[0074] Figure 4 This is a flowchart illustrating a multi-station sequential cleaning method for an air conditioner muffler according to an embodiment of this application.

[0075] Explanation of reference numerals in the attached figures: 110. First tank; 120. Second tank; 130. Ultrasonic generator array; 140. Water quality detection element; 210. Third tank; 220. Fourth tank; 230. Concentration detection element; 310. Fifth tank; 320. Sixth tank; 330. Sliding cover; 340. Heating module; 350. Humidity detection element; 360. Position detection element; 410. Main crossbeam; 420. First hook assembly; 430. Second hook assembly; 440. Basket; 510. Distance sensor; 520. Release actuator; 530. Receiving trolley; 540. Hardware interlock element; 550. Mechanical contact confirmation element; 600. Main control system. Detailed Implementation

[0076] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0077] This application discloses a multi-station sequential cleaning system for air conditioner mufflers. The air conditioner muffler, as described in this application, is a sheet metal component in an air conditioning refrigeration system used to reduce refrigerant flow noise. It has a deep cavity structure formed by multiple layers of bending. Six processing tanks are arranged sequentially in a straight line along the same direction, forming six processing stations: an ultrasonic degreasing unit, a room-temperature water rinsing and rust prevention unit, and a constant-temperature closed-loop drying unit. A sequentially coordinated conveyor crane is a transport mechanism that carries baskets between the tanks. The baskets are workpiece carriers that hold the mufflers and are transferred between the tanks by the crane. A terminal anti-foolproof sensing unloading unit is a unloading mechanism that controls the release of workpieces based on receiving conditions at the end. This system, by arranging the degreasing, water rinsing and rust prevention, and closed-loop drying sections sequentially in a straight line and scheduling them sequentially by the main control system, combined with cross-coordinated transport by two hook assemblies and terminal receiving cart sensing gate control, ensures the reliability of each processing stage of the deep cavity muffler during continuous unmanned operation. First, the ultrasonic degreasing unit removes cutting fluid and deep-cavity metal debris from the workpiece surface. Then, a room-temperature water rinsing and rust prevention unit completes the replacement and rust prevention. Finally, a constant-temperature closed drying unit evaporates any remaining moisture in the deep cavity, and the workpiece is then unloaded using a fail-safe end-of-line method. This allows for unattended continuous operation, avoiding incomplete drying, cross-tank contamination, and drops due to lack of end-of-line support, common in open-loop fixed-cycle systems. The following details the embodiment of this application, including its overall system composition, ultrasonic degreasing unit, room-temperature water rinsing and rust prevention unit, constant-temperature closed drying unit, time-coordinated flow crane, fail-safe end-of-line loading unit, global scheduling of the main control system, and corresponding cleaning methods.

[0078] Reference Figure 1The multi-station sequential cleaning system for air conditioner mufflers in this application includes six sets of processing tanks arranged in a straight line, a sequential collaborative transfer crane passing through the top of the six sets of processing tanks, a foolproof sensing unloading unit located at the end, and a main control system 600. The six sets of processing tanks include an ultrasonic degreasing unit, a room temperature water rinsing and rust prevention unit, and a constant temperature closed drying unit; the ultrasonic degreasing unit includes a first tank 110 and a second tank 120, each of which is equipped with an ultrasonic generator array 130; the room temperature water rinsing and rust prevention unit includes a third tank 210 serving as a clean water overflow tank and a fourth tank 220 serving as a rust-preventing liquid tank; the constant temperature closed drying unit includes a fifth tank 310 and a sixth tank 320, each of which has a sliding cover 330 and a heating module 340. When the sliding cover 330 is closed, it forms a closed cavity with the corresponding tank, and the heating module 340 operates at the drying temperature. The sequential collaborative transfer crane includes a main crossbeam 410 extending along the arrangement direction of six sets of processing tanks, and a first hook assembly 420 and a second hook assembly 430 suspended from the main crossbeam 410. The first hook assembly 420 and the second hook assembly 430 cross-coordinately support the basket 440 containing the muffler, and enable the basket 440 to be lifted, translated, and lowered sequentially between the six sets of processing tanks, thereby transferring the basket 440 from the previous processing tank to the next processing tank. The end-of-line foolproof sensing unloading unit is located in the unloading area downstream of the constant temperature closed drying unit, including a distance sensor 510 and a release actuator 520. The distance sensor 510 detects the receiving carriage 530 in the unloading area, and the release actuator 520 unlocks when the receiving carriage 530 is in place, so as to release the muffler in the basket 440 to the receiving carriage 530. The main control system 600 is connected to the ultrasonic generator array 130, heating module 340, time-coordinated flow crane, sliding cover 330, distance sensor 510 and release actuator 520 to coordinate the time-coordinated flow of basket 440 between the six processing tanks.

[0079] The muffler has a deep cavity structure formed by multiple bends, making it easy for cutting fluid and metal shavings to get trapped in the bends and blind spots of the deep cavity. Residual moisture in the deep cavity is also difficult to evaporate completely during drying. Because the three processing sections are arranged sequentially in a straight line and uniformly scheduled by the main control system 600, the deep cavity muffler completes the removal of cutting fluid and shavings, rust prevention treatment, and deep cavity drying sequentially on the same production line. The first hook assembly 420 and the second hook assembly 430 work together to transport materials, allowing the next basket to move to an adjacent slot while the previous basket is still being processed in a certain tank, thus increasing the turnover rate without increasing the number of transport mechanisms. The end-of-line error-proof sensing unloading unit releases the workpiece only after confirming the acceptance conditions, ensuring that the status of each processing unit, the transfer crane, and the unloading unit is integrated into the closed-loop coordination of the main control system 600. In an exemplary application scenario, the basket 440 holds the deep cavity muffler to be cleaned, and the processing cycle in each tank is approximately 5 minutes, completing the cleaning station by station. Through the above overall structure, the deep cavity muffler completes thorough cleaning, rust prevention, and deep cavity drying in a continuous, unmanned operation, and avoids dropping due to lack of support during the unloading process. This system is not limited to air conditioner mufflers; the same processing section arrangement and sequential collaborative operation method can also be used for other sheet metal parts with deep cavities or multi-layered bending structures that require sequential cleaning and drying at multiple stations.

[0080] In the ultrasonic degreasing unit, the first tank 110 and the second tank 120 respectively perform primary and secondary ultrasonic degreasing on the silencer in the basket 440. The ultrasonic generator arrays 130 of the first tank 110 and the second tank 120 generate ultrasonic vibrations in the cleaning fluid at 50°C to 60°C, causing the cutting fluid and oil stains on the surface and deep cavity of the workpiece to fall off, and flushing loose metal debris out of the deep cavity. A fixed degreasing cycle is difficult to take into account workpieces with different levels of contamination. Therefore, in some embodiments, the ultrasonic degreasing unit also includes a water quality detection element 140 for detecting the turbidity or conductivity of the cleaning fluid in the tank. The water quality detection element 140 may be a turbidity sensor or conductivity sensor installed in the first tank 110 and / or the second tank 120, mounted on the side wall of the tank near the circulation outlet, to collect the turbidity or conductivity of the tank fluid as the degreasing process progresses. Oil and cutting fluid on the workpiece surface and in the deep cavity are detached and enter the bath solution under ultrasonic vibration, causing the turbidity of the bath solution to increase and the conductivity to change. The greater the amount of detachment, the more significant the change in turbidity or conductivity. The main control system 600 uses this to infer the amount of residual contamination in the silencer in the basket 440. Specifically, the main control system 600 estimates the amount of residual contamination based on the deviation of the turbidity of the bath solution from the clean bath solution reference. The amount of residual contamination Q increases monotonically with the turbidity deviation ΔN. For example, Q = k·ΔN, where ΔN is the difference between the current turbidity and the turbidity of the clean bath solution reference, and k is the calibration coefficient. The calibration coefficient k is related to the sensor range and the type of bath solution and is obtained by calibration using samples with known contamination levels. For example, in a calibration example where turbidity NTU is used for measurement and the amount of residual contamination is taken as a relative amount, the calibration coefficient k is approximately 1.0. The main control system 600 adjusts the degreasing cycle of the basket 440 in the ultrasonic degreasing unit according to the amount of residual contamination. A shorter degreasing cycle is used when the amount of residual contamination is small, and a longer cycle is used when the amount is large. For example, a base degreasing cycle of approximately 5 minutes is used, and for heavily contaminated workpieces, the cycle is extended proportionally to approximately 7 to 8 minutes. Water quality characterization to estimate the amount of residual contamination is not limited to turbidity. In other embodiments, conductivity methods can be used to characterize dissolved ionic contamination by changes in the conductivity of the bath solution, or online total organic carbon detection can be used to characterize oily contamination. These characterization methods can be used individually or in combination. If feedback from the water quality detection element 140 is missing or abnormal, the main control system 600 reverts to a preset fixed degreasing cycle to ensure uninterrupted degreasing treatment.

[0081] The main control system 600 can adjust the degreasing cycle time according to the amount of residual contamination using a tiered approach. In one optional implementation, the main control system 600 extends the degreasing cycle time of the basket 440 in the ultrasonic degreasing unit according to the amount of residual contamination. The greater the amount of residual contamination, the longer the degreasing cycle time. For example, the residual contamination amount is planned to be divided into three tiers based on the deviation from the cleanliness benchmark. The first threshold is about 20%, and the second threshold is about 50%. The deviation is below the first threshold, which is the low tier, maintaining a basic degreasing cycle time of about 5 minutes; the deviation is between the first and second thresholds, which is the medium tier, which is extended to about 6 minutes; and the deviation is above the second threshold, which is the high tier, which is extended to about 7 to 8 minutes. This allows for a longer degreasing time for heavily contaminated workpieces and prevents lightly contaminated workpieces from being over-treated.

[0082] As an optional implementation, the main control system 600 can also set the degreasing cycle according to the model of the muffler in the basket 440 by looking up a table. A correspondence table between the model and the degreasing cycle is established in advance according to the deep cavity structure and typical residual amount of different models of mufflers. During loading, the corresponding degreasing cycle is read according to the model of the muffler. For example, about 5 minutes is set for a model with fewer deep cavity layers, and about 7 minutes is set for another model with more deep cavity layers and more complex structure, so as to pre-set the corresponding processing time for workpieces with different structures.

[0083] As degreasing continues, the accumulated oil in the tank solution will reduce the degreasing efficiency. In some embodiments, the main control system 600, based on the cumulative trend of turbidity or conductivity measured by the water quality detection element 140, triggers the replenishment or replacement of the cleaning fluid in the ultrasonic degreasing unit and temporarily suspends the upstream feed when the accumulated contamination exceeds a preset threshold. The contamination accumulation trend can be obtained by statistical analysis or cumulative integration of turbidity or conductivity through a sliding window. For example, the trigger is set when the cumulative deviation of turbidity from the cleanliness benchmark reaches three times the set benchmark. After triggering, the cleaning fluid is replenished or replaced to account for approximately 10% to 30% of the tank volume, so that the degreasing efficiency does not continue to decline due to tank saturation.

[0084] In other embodiments, the ultrasonic generator array 130 is excited in a frequency sweep mode or a zone-by-zone alternating mode. The frequency sweep mode continuously changes the excitation frequency within a frequency band, while the zone-by-zone alternating mode allows the ultrasonic transducers in each zone of the array to work in turn, thereby eliminating the cleaning blind zone formed by the standing waves of the sound field in the tank at a fixed frequency. For example, the frequency sweep is performed in the frequency band from 28kHz to 40kHz, or the ultrasonic generator array 130 is divided into two zones and the two zones work alternately, so that each part of the deep cavity obtains a more uniform ultrasonic cleaning effect.

[0085] After ultrasonic degreasing, the basket 440 is transferred to the room temperature rinsing and rust prevention unit. First, it is rinsed with water in the third tank 210, which serves as a clean water overflow tank, to remove residual degreasing liquid. Then, it is immersed in the fourth tank 220, which serves as a rust prevention liquid tank, at room temperature for rust prevention. In some embodiments, the room temperature rinsing and rust prevention unit also includes a concentration detection element 230 for detecting the concentration of the rust prevention liquid in the rust prevention liquid tank. The concentration detection element 230 can be a conductivity type or a refractive concentration sensor. The main control system 600 replenishes the rust prevention liquid tank with rust prevention concentrate when the concentration of the rust prevention liquid is lower than a preset concentration. For example, the rust prevention liquid concentration is maintained within a preset range of 3% to 8%. When the concentration is lower than the lower limit of this range, the rust prevention concentrate is replenished to maintain the effectiveness of the rust prevention treatment at a preset level.

[0086] Reference Figure 2 After water-based rust prevention, the basket 440 is transferred to the constant-temperature closed drying unit. When the basket 440 moves horizontally above the fifth tank 310 or the sixth tank 320, the corresponding sliding cover 330 of the tank opens, the basket 440 descends and enters, the sliding cover 330 closes, and forms a closed cavity with the corresponding tank. The heating module 340 operates at the drying temperature, for example, at about 120°C, to evaporate the residual rust-preventing water film in the deep cavity of the silencer. The deep cavity structure makes it difficult for residual moisture to evaporate completely. If the drying time is fixed, complex-structured and heavy-load workpieces may not be thoroughly dried, while simple-structured workpieces may be overheated. Therefore, in some embodiments, the constant-temperature closed drying unit also includes a humidity detection element 350 for detecting the humidity of the air venting from the closed cavity. The main control system 600 determines the drying endpoint based on the air vent humidity and stops heating the closed cavity accordingly. The humidity detection element 350 can be a humidity sensor installed at the air vent of the closed cavity to collect the humidity of the air venting from the cavity as the moisture in the deep cavity evaporates. In the initial heating stage, a large amount of moisture evaporates from the deep cavity, resulting in high humidity at the outlet. As the deep cavity dries, the evaporation rate decreases, and the outlet humidity drops accordingly. The main control system 600 determines that the drying endpoint has been reached when the outlet humidity drops to a level indicating that moisture evaporation is complete, and then stops heating the sealed cavity. The endpoint criterion for outlet humidity can be a relative humidity dropping to a preset threshold, for example, a relative humidity of 10% to 20% at the outlet of the sealed cavity. The specific threshold is selected within this range based on the volume of the sealed cavity, the loading capacity, and the ambient humidity. The physical quantity characterizing the degree of dryness of the deep cavity is not limited to relative humidity. In other embodiments, the dew point temperature of the air escaping from the cavity or the mass loss curve of the workpiece during the drying process can be used to determine whether the drying endpoint has been reached.

[0087] The airtightness of the sealed cavity is a prerequisite for the validity of the outlet humidity criterion. In some embodiments, the constant temperature sealed drying unit also includes a position detection element 360 for detecting the closing position of the sliding cover 330. When the sliding cover 330 is not fully closed, the main control system 600 temporarily suspends the heating module 340 from operating at the drying temperature. The drying endpoint determination based on the outlet humidity is activated only after the sliding cover 330 is fully closed. When the sliding cover 330 is not fully closed, there is hot air leakage in the sealed cavity, and the outlet humidity inside the cavity is distorted by the external environment. If the endpoint is determined based on the outlet humidity at this time, it is easy to cause misjudgment of the drying endpoint and energy loss due to hot air leakage. The humidity criterion is established on the premise that the sealed cavity is airtight.

[0088] The drying endpoint criterion for the exhaust humidity can be implemented in several ways. Specifically, the main control system 600 can determine that the drying endpoint has been reached if the exhaust humidity decreases at a rate lower than a preset rate, or if the exhaust humidity remains lower than the preset humidity for a duration exceeding a preset holding time. The former indicates that the evaporation rate of moisture in the deep cavity has slowed down, while the latter indicates that the cavity has been maintained in a low humidity state. For example, the preset rate criterion can be set by the exhaust relative humidity decreasing at a rate lower than 1% per minute, or the preset humidity and preset holding time can be set by the exhaust relative humidity remaining lower than 15% for a duration exceeding 1 minute.

[0089] The bends and blind spots in the deep cavity may cause delayed evaporation of moisture, leading to an earlier determination of the endpoint. In some embodiments, after determining that the drying endpoint has been reached, the main control system 600 maintains the heating module 340 for approximately 0.5 to 1 minute for a retest period and remeasures the humidity of the air escaping the sealed cavity. If the remeasured relative humidity of the air escaping rises by more than 3 percentage points compared to the endpoint, it is determined to have rebounded, and the constant temperature sealed drying is extended to avoid misjudgment of the endpoint caused by delayed evaporation of moisture in the deep cavity and dead space.

[0090] As an optional implementation of the positioning detection element 360, the positioning detection element 360 may be a limit switch set at the end of the travel of the sliding cover 330, or a pressure detection element that detects the sealing pressure of the sliding cover 330. The former is triggered when the cover reaches the end of the travel, and the latter is confirmed to be in position when the cover is pressed tightly against the sealing surface to reach the preset sealing pressure.

[0091] The loading conditions of different batches of workpieces vary, and the drying presets for subsequent batches can be adjusted based on the historical drying process. In some embodiments, the main control system 600 records the drying curve of the humidity of the air vent in the closed chamber over time. When the time to reach the drying endpoint exceeds the preset time, the preset time for constant temperature closed drying of subsequent batches is extended and a prompt to reduce the loading amount is issued. For example, the trigger is set when the time to reach the drying endpoint exceeds 1.2 times the conventional drying time of the model, and the preset drying time of subsequent batches is extended by 10% to 20%, so that the drying parameters adapt to the loading conditions.

[0092] The constant temperature closed drying unit can also be equipped with a waste heat recovery channel that leads the waste heat discharged from the heating module 340 to the ultrasonic degreasing unit. The waste heat recovery channel leads the waste heat of the drying section to the degreasing section for preheating the degreasing tank liquid, thereby reducing the heating energy consumption of the heating module of the degreasing unit.

[0093] After processing in each stage, the transfer of the basket 440 between the six processing tanks is accomplished by the cross-coordination of the first hook assembly 420 and the second hook assembly 430 of the time-coordinated transfer crane. When the two hook assemblies hand over the basket 440 at the handover point, it is crucial to ensure that the basket 440 does not detach during the handover process. Therefore, in some embodiments, the main control system 600 performs interlocking handshake control when the first hook assembly 420 and the second hook assembly 430 hand over the basket 440 at the handover point. This ensures that the hook assembly that arrives at the handover point first locks the basket 440 before the other hook assembly releases it. During the handover process, the basket 440 is always held by at least one of the first hook assembly 420 and the second hook assembly 430. This lock-then-release handshake sequence prevents the two hook assemblies from simultaneously detaching from the basket 440 during the entire handover process, thus avoiding detachment during cross-coordinated transport.

[0094] When the basket 440 is transferred between adjacent processing tanks, it carries away the processing liquid adhering to the workpiece and the basket 440. In some embodiments, the main control system 600 controls a time-coordinated transfer crane to lift the basket 440 from the current processing tank, hover it above the current processing tank for a preset draining time, and then transfer it to the processing tank adjacent to the current processing tank. After the basket 440 is lifted, it hovers above the original tank, allowing the adhering processing liquid to drip back into the original tank, reducing cross-contamination caused by the processing liquid being carried into adjacent tanks.

[0095] When the first hook assembly 420 and the second hook assembly 430 operate in a coordinated manner, their flow paths may intersect on the main crossbeam 410. In some embodiments, the first hook assembly 420 and the second hook assembly 430 share the main crossbeam 410. The main control system 600 maintains that the distance between the first hook assembly 420 and the second hook assembly 430 on the main crossbeam 410 is not less than a preset safety distance. When the flow paths of the first hook assembly 420 and the second hook assembly 430 intersect, it controls one of the hook assemblies to retreat to a clearance position and resumes flow after the other hook assembly has passed. Sharing the same main crossbeam 410 for the two hook assemblies simplifies the crane structure, but it also introduces the possibility of collision between the two on the crossbeam. Maintaining a safety distance of not less than a preset safety distance and causing one to retreat when their paths intersect ensures that the relative movement of the two hook assemblies on the shared crossbeam always maintains a safe distance. For example, the preset safety distance can be set to not less than the width of a basket, or to 0.5m to 1m, depending on the size of the basket and the crane stroke. The methods to avoid collision between the two hook components are not limited to spatial avoidance. In other embodiments, the actions of the two hook components can be staggered in time, so that only one hook component moves in the intersection section at the same time, or the first hook component 420 and the second hook component 430 can be placed on two horizontal beams of different layers to separate their movement paths in space.

[0096] The interlock handshake at the handover position can be signal-driven. Specifically, the interlock handshake control causes the hook assembly that arrives at the handover position first to send a takeover permission signal to the other hook assembly after locking the handover position. Upon receiving the takeover permission signal, the other hook assembly releases the basket 440, so that the handover between the two hook assemblies is driven by the takeover permission signal rather than switching based on time estimation.

[0097] The duration of the basket 440 hovering above each treatment tank for dripping can be set according to the properties of the treated liquid. In an optional embodiment, the main control system 600 sets the dripping duration based on the type of liquid contained in adjacent treatment tanks, setting a longer dripping duration for higher viscosity treated liquids, such as about 2 to 3 seconds for low viscosity clean water and about 5 to 8 seconds for high viscosity rust inhibitors, so that treated liquids with a large amount of adhesion can obtain sufficient back-drip time.

[0098] The time-coordinated transfer crane can also be equipped with a positioning detection element to detect the positioning status of the basket 440. When the basket 440 is not in position or is jammed, the main control system 600 controls the machine to stop and alarm, so as to prevent the handling mechanism from continuing to operate under the abnormal state of the basket 440 not in position or jammed, which may cause damage.

[0099] If one of the two hook assemblies fails, the other hook assembly can be degraded to maintain operation to avoid a complete production line shutdown. In some embodiments, when one of the first hook assembly 420 and the second hook assembly 430 fails, the main control system 600 uses the other hook assembly to continue carrying the basket 440 between the six processing tanks in a single-hook degraded manner. For example, during single-hook degraded operation, the hook assembly carries the basket back and forth, extending the cycle time to 1.5 to 2 times that of the double-hook cross-cooperation, so that the entire production line does not stop even if the cycle time is sacrificed in the event of a partial failure.

[0100] Reference Figure 3 After being dried in a constant-temperature sealed drying unit, the basket 440 is moved to the downstream unloading area by a time-coordinated transfer crane. The distance sensor 510 of the end-of-line foolproof unloading unit probes downwards towards the ground-facing docking position. The main control system 600 determines whether a receiving cart 530 exists at the docking position based on feedback from the distance sensor 510. Only after confirming the receiving conditions does it control the release actuator 520 to unlock and release the muffler from the basket 440 to the receiving cart 530. However, if the release condition is solely based on the presence or absence of a receiving cart 530, situations where the receiving cart 530 is in place but not aligned or is already full may still cause workpiece misalignment, falling, or stacking and crushing. Therefore, in some embodiments, the distance sensor 510 detects the presence, alignment, and full load status of the receiving cart 530, and the release actuator 520 only unlocks when the receiving cart 530 is in place, aligned, and not fully loaded. Specifically, the distance sensor 510 receives feedback from multiple detection positions facing the ground. It determines the receiving cart 530 is in place based on the presence of continuous feedback at the docking position, whether the receiving cart 530 is aligned based on the consistency of feedback from each detection position, and whether the receiving cart 530 is fully loaded based on feedback changes corresponding to the material level within the receiving cart 530. The main control system 600 only controls the release actuator 520 to unlock when the receiving cart 530 is in place, aligned, and has sufficient space. In an exemplary unloading scenario, if the receiving cart 530 is in place but deviates from the centerline of the docking position, the main control system 600 determines it is not aligned based on inconsistencies in feedback from various positions and does not unlock. If the receiving cart 530 is full, the main control system 600 determines it is fully loaded based on material level feedback and does not unlock. The workpiece is released only when the receiving cart 530 is in place, aligned, and not fully loaded. The pre-unloading judgment is expanded from a simple presence or absence of a receiving device to three dimensions: in-place, aligned, and fully loaded. This ensures that the workpiece is only released when the receiving device is in place, aligned, and there is still room to accommodate it, reducing misalignment, drops, and stacking compression. The sensing method for determining the status of the receiving cart 530 is not limited to distance measurement. In other embodiments, in-place detection can be achieved by distance measurement, alignment detection by visual alignment, and full load detection by weighing, covering the three dimensions of judgment respectively.

[0101] In a misty environment, the distance sensor 510 may experience missing or abnormal feedback due to water mist obscuring its signal. In such cases, the release action should not be initiated rashly when the sensor fails. In some embodiments, the end-effector anti-mistake sensing unloading unit further includes a hardware interlock element 540 connected in series in the unlocking circuit of the release actuator 520. When the distance sensor 510 experiences missing or abnormal feedback, the hardware interlock element 540 locks the release actuator 520 to the non-release side in a fail-safe manner and triggers an audible and visual alarm. The hardware interlock element 540 is located on the path of the unlocking circuit. When the distance sensor 510 provides normal feedback, the unlocking circuit can be turned on. When the feedback is missing or abnormal, the unlocking path is directly disconnected, causing the failure of the distance sensor 510 to be converted into a stop rather than accidental release.

[0102] If the unloading area cannot be completed for an extended period, the basket 440 will remain suspended in the unloading area, causing the deep-cavity workpieces to rust in the workshop's water mist environment. Therefore, in some embodiments, when the suspension time of the basket 440 in the unloading area exceeds a preset time threshold, the main control system 600 controls a timing-coordinated crane to retract the basket 440 to one of the emptied drying tanks, either the fifth tank 310 or the sixth tank 320, and operates the heating module 340 of the drying tank at a drying temperature lower than the actual drying temperature. After the basket 440 is retracted to the emptied drying tank, it is dried at a low temperature to prevent the waiting deep-cavity workpieces from rusting in the workshop's water mist environment. Once the unloading conditions are restored, it is returned to the unloading area for release. For example, the suspension time threshold for triggering the retraction is set to the basket 440 remaining suspended in the unloading area for more than 1 to 2 minutes, and the drying temperature is set to approximately 50°C to 80°C lower than the actual drying temperature. The protection method for the basket 440 during the waiting period is not limited to retracting the drying tank. In other embodiments, the basket 440 may be suspended in place in the unloading area, or a temporary drying position may be set up separately near the unloading area to accommodate the waiting basket 440.

[0103] As a redundancy for the distance sensor 510, the end-point foolproof sensing unloading unit may also include a mechanical contact confirmation element 550 arranged in parallel with the distance sensor 510. When the feedback from the distance sensor 510 is missing, the main control system 600 uses the confirmation result of the mechanical contact confirmation element 550 as the unlocking criterion for the release actuator 520, providing a backup sensing independent of the distance measurement for gate control judgment.

[0104] The response to the suspension in the unloading area can be graded according to the suspension duration. In one optional implementation, the main control system 600 responds in stages according to the suspension duration of the basket 440 in the unloading area. When the suspension duration is within a first time threshold, the basket 440 is kept suspended. When the suspension duration exceeds the first time threshold, a reversal drying is performed. When the suspension duration exceeds a second time threshold, the flow rate is reduced and the audible and visual alarms are upgraded. For example, the first time threshold is about 1 minute and the second time threshold is about 3 minutes, so that the response to the unloading abnormality matches the duration.

[0105] After the basket 440 is retracted for drying, its hook assembly can be freed up for continued handling. In some embodiments, after the basket 440 is retracted to the drying tank for drying, the main control system 600 controls the timing coordinated transfer crane to use the freed-up hook assembly to carry the remaining baskets for continued transfer, so that the transfer of upstream processing tanks is not interrupted when the material discharge is obstructed.

[0106] The distance sensor 510 can be implemented by a non-contact device. In some embodiments, the distance sensor 510 is a photoelectric sensor that enables non-contact detection of the material receiving car 530 in the unloading area in a photoelectric manner.

[0107] After the receiving car 530 is full, it needs to be replaced with an empty car, and the upstream flow should not be interrupted during the replacement. In some embodiments, when the receiving car 530 is full, the main control system 600 issues an empty car dispatch request and retracts the subsequent basket 440 to the fifth tank 310 or the sixth tank 320 for drying. After the empty receiving car 530 arrives, it resumes release, so that the replacement of the unloading receiving device does not interrupt the upstream flow.

[0108] The processing capacity and cycle time of each processing section may be inconsistent. When a certain processing section becomes a bottleneck, continuous feeding upstream will cause work-in-process to accumulate. In some embodiments, when the drying time of the constant temperature closed drying unit is extended, or when the basket 440 retracts and occupies one of the drying tanks in the constant temperature closed drying unit, the main control system 600 reduces the feeding cycle time of the upstream ultrasonic degreasing unit and the room temperature water rinsing and rust prevention unit, so that the number of work-in-process in each processing tank matches its processing capacity, thus avoiding upstream accumulation.

[0109] Based on the above system, this application embodiment also provides a multi-station sequential cleaning method for air conditioner mufflers. This method is applied to the aforementioned cleaning system, which includes six sets of processing tanks arranged in a straight line, a sequentially coordinated rotating crane with a first hook assembly 420 and a second hook assembly 430, and a distance sensor 510 located in the end unloading area. The first tank 110 and the second tank 120 in the six sets of processing tanks constitute an ultrasonic degreasing unit; the third tank 210 is a clean water overflow tank; the fourth tank 220 is a rust-preventive liquid tank; and the fifth tank 310 and the sixth tank 320 each have a sliding cover 330, which forms a closed cavity when the sliding cover 330 is closed. (Refer to...) Figure 4 The method includes the following steps: S1. The control sequence coordinates the flow of the crane to sink the basket 440 containing the silencer into the first groove 110 and the second groove 120, and performs ultrasonic degreasing on the silencer in the basket 440.

[0110] S2. After rinsing the basket 440 with clean water in the third tank 210, transfer it to the fourth tank 220 for immersion in rust-preventive liquid, and suspend the basket 440 to drain the liquid before transferring it to the adjacent treatment tank.

[0111] S3. In response to the basket 440 being moved to the top of the fifth slot 310 or the sixth slot 320, the sliding cover 330 below the basket 440 is triggered to open. After the basket 440 descends and enters, the sliding cover 330 is closed to form a closed cavity, and the closed cavity is heated to dry the muffler.

[0112] S4. Move the dried basket 440 to the unloading area. In response to the distance sensor 510 detecting that the receiving carriage 530 is in place, aligned and not fully loaded, unlock and release the muffler to the receiving carriage 530. In response to the receiving carriage 530 not being in place, lock and do not release. In response to the basket 440 hovering in the unloading area for a timeout, return the basket 440 to one of the empty slots 310 or 320 for drying.

[0113] The above method applies degreasing, water rinsing for rust prevention, and closed drying sequentially to the deep cavity muffler on the same production line in the order of S1 to S3, so that the removal of cutting fluid and debris, rust prevention, and deep cavity drying are completed in a continuous flow. In S2, water rinsing and suspension draining are used to connect degreasing and rust prevention, reducing the amount of treatment fluid carried over to other tanks. In S3, the closed door forms a closed cavity for reheating, allowing the moisture in the deep cavity to evaporate in a sealed environment. In S4, the presence, alignment, and full load of the receiving cart 530 are used as release conditions, and the basket 440 that has been suspended for too long is returned for drying, so that the unloading process will not fall or rust back when there is a lack of receiving or a long waiting time. Thus, the reliability of each processing stage is ensured in a continuous unmanned flow. The above method is also applicable to other sheet metal parts with deep cavity structures that require multi-station sequential cleaning and drying.

[0114] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above.

[0115] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A multi-station sequential cleaning system for air conditioner mufflers, characterized in that, include: The system comprises six sets of processing tanks arranged in a straight line. Each set includes an ultrasonic degreasing unit, a room-temperature water rinsing and rust prevention unit, and a constant-temperature closed drying unit. The ultrasonic degreasing unit includes a first tank and a second tank, each equipped with an ultrasonic generator array. The room-temperature water rinsing and rust prevention unit includes a third tank serving as a clean water overflow tank and a fourth tank serving as a rust-preventing liquid tank. The constant-temperature closed drying unit includes a fifth tank and a sixth tank, each equipped with a sliding cover and a heating module. When closed, the sliding cover forms a closed cavity with the corresponding tank. The heating module is configured to operate at the drying temperature. The sequential collaborative flow crane includes a main crossbeam extending along the arrangement direction of the six sets of processing tanks, and a first hook assembly and a second hook assembly suspended from the main crossbeam. The first hook assembly and the second hook assembly are configured to cross-cooperatively carry a basket containing a silencer and to allow the basket to flow between the six sets of processing tanks. The end-of-line foolproof sensing unloading unit is located in the unloading area downstream of the constant temperature closed drying unit, and includes a distance sensor and a release actuator. The distance sensor is configured to detect the receiving cart in the unloading area, and the release actuator is configured to unlock when the receiving cart is in place to release the muffler in the basket to the receiving cart. The main control system, connected to the ultrasonic generator array, the heating module, the time-coordinated transfer crane, the sliding cover, the distance sensor, and the release actuator, is configured to coordinate the time-coordinated transfer of the basket between the six processing tanks. The main control system is also configured to: respond to a basket's hovering time in the unloading area exceeding a preset time threshold, control the time-coordinated transfer crane to retract the basket to one of the vacated drying tanks in the fifth and sixth tanks, and to operate the heating module of the drying tank at a drying temperature lower than the drying temperature; control the time-coordinated transfer crane to use the vacated hook assembly to carry the remaining baskets for continued transfer; respond to the basket's retraction occupying one drying tank in the constant-temperature closed drying unit, reduce the cycle time of the ultrasonic degreasing unit and the ambient-temperature water rinsing and rust prevention unit; and after the receiving car returns to its position, control the time-coordinated transfer crane to rotate the retracted basket back to the unloading area for release; wherein the fifth and sixth tanks are drying tanks.

2. The multi-station sequential cleaning system for air conditioner mufflers according to claim 1, characterized in that, The distance sensor is configured to detect the position, alignment, and full load status of the receiving car. The release actuator is configured to unlock only when the receiving car is in position, aligned, and not fully loaded. The distance sensor probes downwards toward the docking position in the unloading area and receives feedback at multiple detection positions facing the ground. The main control system is configured to determine the position of the receiving car based on the presence of continuous feedback at the docking position, determine whether the receiving car is aligned based on the consistency of feedback from each detection position, and determine whether the receiving car is fully loaded based on the feedback change corresponding to the material level in the receiving car. The main control system is also configured to, in response to the receiving car being fully loaded, issue an empty car dispatch request and return the subsequent basket to the fifth or sixth drying tank, and resume release after the empty receiving car arrives.

3. The multi-station sequential cleaning system for air conditioner mufflers according to claim 2, characterized in that, The end-of-line error-proof sensing unloading unit also includes a hardware interlocking element connected in series in the unlocking circuit of the release actuator. The hardware interlocking element is configured to lock the release actuator to the non-release side and trigger an audible and visual alarm in a fail-safe manner when the feedback from the distance sensor is missing or abnormal. The main control system is configured to respond in stages according to the suspension time of the basket in the unloading area. When the suspension time is within a first time threshold, the basket is kept suspended. When the suspension time exceeds the first time threshold, the retraction is executed. When the suspension time exceeds a second time threshold, the flow rate is reduced and the audible and visual alarm is upgraded. The preset time threshold is the first time threshold.

4. The multi-station sequential cleaning system for air conditioner mufflers according to claim 1, characterized in that, The constant temperature sealed drying unit also includes a humidity detection element for detecting the humidity of the air venting from the sealed cavity. The main control system is configured to determine the drying endpoint based on the air venting humidity and stop heating the sealed cavity accordingly. The main control system is also configured to reduce the cycle time of the ultrasonic degreasing unit and the room temperature water rinsing and rust prevention unit in response to the extension of the drying time of the constant temperature sealed drying unit, and record the drying curve of the air venting humidity of the sealed cavity over time. In response to the time taken to reach the drying endpoint exceeding a preset time, the system extends the preset time of constant temperature sealed drying for subsequent batches and issues a prompt to reduce the loading amount.

5. The multi-station sequential cleaning system for air conditioner mufflers according to claim 4, characterized in that, The constant temperature sealed drying unit also includes a detection element for detecting when the sliding cover door is closed. The main control system is configured to temporarily suspend the operation of the heating module at the drying temperature in response to the sliding cover door not being closed, and then activate the drying endpoint determination based on the exhaust humidity after the sliding cover door is closed. The main control system is also configured to maintain the operation of the heating module for a preset re-inspection time and re-measure the exhaust humidity in the sealed cavity after determining that the drying endpoint has been reached. In response to the re-measured exhaust humidity rising, the constant temperature sealed drying is extended.

6. The multi-station sequential cleaning system for air conditioner mufflers according to claim 1, characterized in that, The main control system is configured to perform interlock handshake control when the first hook assembly and the second hook assembly hand over the basket at the handover position, such that the hook assembly that arrives at the handover position first locks the basket before the other hook assembly releases the basket, and the basket is always held by at least one of the first hook assembly and the second hook assembly during the handover process; the interlock handshake control causes the hook assembly that arrives at the handover position first to send a takeover permission signal to the other hook assembly after locking the handover position, and the other hook assembly releases the basket in response to the takeover permission signal.

7. The multi-station sequential cleaning system for air conditioner mufflers according to claim 1, characterized in that, The first hook assembly and the second hook assembly share the main crossbeam. The main control system is configured to maintain the distance between the first hook assembly and the second hook assembly on the main crossbeam at no less than a preset safety distance. In response to the intersection of the flow paths of the first hook assembly and the second hook assembly, the system controls one of the hook assemblies to retreat to a clearance position and resumes flow after the other hook assembly has passed. The main control system is also configured to respond to a failure of one of the first hook assembly and the second hook assembly, and to continue to carry the basket between the six sets of processing tanks with a single hook of the other hook assembly.

8. The multi-station sequential cleaning system for air conditioner mufflers according to claim 1, characterized in that, The main control system is configured to control the time-coordinated flow crane, so that after the basket is lifted from the current processing tank, it is suspended above the current processing tank for a preset draining time, and then transferred to the processing tank adjacent to the current processing tank; the ultrasonic degreasing unit also includes a water quality detection element for detecting the turbidity or conductivity of the cleaning fluid in the tank, and the main control system is configured to infer the residual contamination amount of the silencer in the basket based on the turbidity or conductivity, and adjust the degreasing rhythm of the basket in the ultrasonic degreasing unit accordingly; the main control system is also configured to, based on the cumulative trend of turbidity or conductivity measured by the water quality detection element, trigger the replenishment or replacement of the cleaning fluid in the ultrasonic degreasing unit and temporarily suspend the upstream feed when the contamination accumulation exceeds a preset threshold, and return to running according to the preset fixed degreasing rhythm when the feedback from the water quality detection element is missing or abnormal.

9. A multi-station sequential cleaning method for an air conditioner muffler, characterized in that, The multi-station sequential cleaning system for air conditioner mufflers according to any one of claims 1-8 includes: S1. Control the timing-coordinated crane to sink the basket containing the silencer into the first and second tanks in sequence, and perform ultrasonic degreasing on the silencer in the basket; S2. After rinsing the basket with clean water in the third tank, transfer it to the fourth tank for immersion in rust-preventive liquid, and suspend the basket to drain the liquid before transferring it to the adjacent treatment tank. S3. In response to the basket being moved to the top of the fifth or sixth slot, the sliding cover under the basket is triggered to open. After the basket descends and enters, the sliding cover is closed to form the enclosed cavity, and the enclosed cavity is heated to dry the silencer. S4. Move the dried basket to the unloading area. In response to the distance sensor detecting that the receiving car is in place, aligned and not fully loaded, unlock and release the muffler to the receiving car. In response to the receiving car not being in place, lock and do not release. In response to the basket being suspended in the unloading area for a timeout, return the basket to one of the emptied slots in the fifth or sixth slot for drying.

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