Clean room cleaning robot passive heat dissipation device and heat management control method

Abstract

The application relates to the technical field of heat dissipation of cleaning robots, and discloses a passive heat dissipation device for a cleaning workshop cleaning robot, which comprises multiple groups of double-layer shells, heat conductors and heat pipes. Each group of double-layer shells comprises inner and outer shells, and a sealed convection cavity is arranged between the inner and outer shells. The multiple groups of double-layer shells respectively wrap control boxes, bottom cavities of transport vehicles, lifting assemblies and joints. Control modules, walking driving plates, lifting driving plates, joint driving plates and battery modules are fixed to the inner shells of the corresponding double-layer shells and are in thermal conduction connection with the inner shells through the heat conductors. The heat pipes are filled in the sealed convection cavities and wrap at least part of the outer walls of the inner shells. The application is connected with the inner shells through the heat conductors by removing the fan, so that heat is conducted to the sealed convection cavities through the inner shells, natural convection heat dissipation is realized, and a heat management control method suitable for the passive heat dissipation device is further provided.

Description

Technical Field

[0001] This application relates to the technical field of heat dissipation for cleaning robots, and more particularly to a passive heat dissipation device and thermal management control method for a cleanroom cleaning robot. Background Technology

[0002] In high-cleanliness workshops such as semiconductor, biopharmaceutical and precision electronics manufacturing, dedicated cleanroom cleaning robots are usually used to remove micro-dust particles from the walls, floors and equipment surfaces. The internal control units and drive motors of these robots generally adopt a fan-type active cooling structure.

[0003] However, this heat dissipation solution has significant technical drawbacks in clean environments: on the one hand, the mechanical friction generated by the high-speed rotation of the bearings and fan blades when the fan is running will inevitably release submicron-sized particles. Cleanrooms have extremely strict requirements for environmental cleanliness. According to GMP and related cleanroom standards, any equipment that generates airflow disturbances or particle emissions must not enter the core production area. However, the friction dust generated by traditional cleaning robots has become a major dynamic source of pollution besides human activity, which can easily cause the cleanliness of local areas to exceed the standard momentarily, thus polluting the clean environment.

[0004] On the other hand, cleanrooms are usually equipped with unidirectional air supply systems. When the fan on the cleaning robot is running, the non-directional forced convection formed will directly interfere with and destroy the original stable unidirectional flow field, causing the airflow to generate eddies or backflow. This not only weakens the self-cleaning ability of the cleanroom itself, but may also cause high-concentration pollutant airflow from the outside to flow back into the clean area, making it impossible for the clean environment to continuously meet the standards when the robot is working, and making it difficult to meet the normal production and operation requirements of the cleanroom.

[0005] Therefore, there is an urgent need for a passive heat dissipation device and thermal management control method for cleanroom cleaning robots to solve the above-mentioned technical problems.

[0006] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0007] The main purpose of this application is to provide a passive heat dissipation device and thermal management control method for a cleanroom cleaning robot, which aims to solve the technical problems in the prior art that the use of fan-type active heat dissipation leads to the release of particulate matter and disruption of the unidirectional flow field, and fails to meet the cleanliness standards and normal production operation requirements of cleanrooms.

[0008] To achieve the above objectives, this application provides a passive heat dissipation device for a cleanroom cleaning robot, which is applied to a cleanroom cleaning robot. The cleanroom cleaning robot includes an automated guided vehicle, a control box, a lifting assembly, and a multi-degree-of-freedom robotic arm. The control box contains a control module and a walking drive plate, the lifting assembly contains a lifting drive plate, each joint of the multi-degree-of-freedom robotic arm contains a joint drive plate, and the bottom cavity of the automated guided vehicle contains a battery module. The passive heat dissipation device is a fanless, fully enclosed structure, comprising multiple sets of double-layer shells, heat conductors, and heat pipes. Each set of double-layer shells includes an inner shell and an outer shell, with a sealed convection cavity provided between the inner shell and the outer shell. Multiple sets of the double-layered shells respectively cover the control box, the bottom cavity of the automated guided vehicle, the lifting assembly, and each joint of the multi-degree-of-freedom robotic arm; The control module, walking drive board, lifting drive board, joint drive board and the battery module are all fixed to the inner shell corresponding to the double shell, and form a thermal conduction connection with the inner shell through the heat conductor; The heat pipes fill each of the sealed convection cavities and at least cover a portion of the outer wall of the inner shell.

[0009] As a preferred embodiment of this application, it also includes an electromagnetic shielding assembly; the electromagnetic shielding assembly includes a conductive shielding layer of the housing, a conductive sealing gasket, and a shielding cable ring; The conductive shielding layer of the housing is attached to the inner and outer surfaces of each set of double-layer housings; The conductive sealing gasket is pressed into the splicing gap of each of the double-layer shells and the assembly gap between each of the double-layer shells, and the two sides of each conductive sealing gasket are respectively in contact with the conductive shielding layer of the adjacent shell. The shielding rings are sleeved at the cable inlet and outlet of each of the double-layer shells, and the outer edge of each shielding ring overlaps and communicates with the conductive shielding layer of the shell. Each of the aforementioned double-layered shells is connected to the robot's grounding terminal via a conductive connector.

[0010] As a preferred embodiment of this application, a sealing component is also included; the sealing component includes a sealing gasket and a miniature fluororubber sealing ring; The sealing gasket is disposed at the joint gap of the plates of each of the double-layer shells to seal the joint gap; The miniature fluororubber sealing ring is disposed at the assembly gap formed by the contact between each of the double-layer shells and the outer wall of the control box, the outer wall of the lifting assembly, and the outer wall of each joint of the multi-degree-of-freedom robotic arm, and is used to seal the assembly gap.

[0011] As a preferred embodiment of this application, the heat conductor is any one or more combinations of a thermal pad, a thermal grease layer, or a metal thermal block, and the heat conductor is sandwiched between the control module, the walking drive plate, the lifting drive plate, each of the joint drive plates, the battery module, and the inner wall of the corresponding inner shell.

[0012] As a preferred embodiment of this application, the heat conductor includes a thermally conductive interface layer, a heat spreader layer, and a thermally conductive adhesive layer stacked sequentially; the thermally conductive interface layer is attached to the surface of the control module, the walking drive plate, the lifting drive plate, each of the joint drive plates, and the battery module; the heat spreader layer is sandwiched between the thermally conductive interface layer and the thermally conductive adhesive layer; and the thermally conductive adhesive layer is attached to the inner wall of the inner shell.

[0013] As a preferred embodiment of this application, the outer shell of the double-layer housing containing the battery module is made of stainless steel and flame-retardant engineering plastic composite, the charging contacts of the battery module are provided with a gold-plated layer, the inner shell is made of aluminum alloy, and the outer shell is made of stainless steel.

[0014] As a preferred embodiment of this application, the cleanroom cleaning robot is also equipped with a controller and multiple temperature sensors; The controller is located inside the control box; Multiple temperature sensors are respectively disposed on the surface of the control module, the walking drive board, the lifting drive board, each of the joint drive boards and the battery module, and each temperature sensor is communicatively connected to the controller.

[0015] A thermal management control method for a passive heat dissipation device of a cleanroom cleaning robot, applicable to any of the above-mentioned passive heat dissipation devices of cleanroom cleaning robots, includes the following steps: The temperature sensors collect the real-time temperatures of the control module, the walking drive board, the lifting drive board, each of the joint drive boards, and the battery module, and send the collected real-time temperature values ​​to the controller. The controller compares each of the real-time temperature values ​​with the corresponding preset safe temperature threshold. When any of the real-time temperature values ​​exceeds the corresponding preset safety temperature threshold, the controller gradually reduces the moving speed of the automated guided vehicle and / or the load of the multi-degree-of-freedom robotic arm until each of the real-time temperature values ​​falls back below the corresponding preset safety temperature threshold. The controller determines whether the heat pipes in each of the sealed convection cavities are in a phase change saturation state based on the rate of change of each of the real-time temperature values. When the controller determines that any of the heat pipes is in a phase change saturation state and the corresponding real-time temperature value continues to rise, the controller controls the robot to enter an intermittent standby mode, suspends operation and maintains the monitoring of each of the temperature sensors; When each of the real-time temperature values ​​falls below the corresponding preset safe temperature threshold, and each of the heat pipes completes condensation and heat release, the controller controls the robot to resume normal operation.

[0016] As a preferred embodiment of this application, the preset safe temperature threshold includes a first temperature threshold and a second temperature threshold, wherein the second temperature threshold is higher than the first temperature threshold. When the real-time temperature value exceeds the first temperature threshold but does not exceed the second temperature threshold, the controller reduces the moving speed of the automated guided vehicle. When the real-time temperature value exceeds the second temperature threshold, the controller simultaneously reduces the moving speed of the automated guided vehicle and the load of the multi-degree-of-freedom robotic arm, and controls the robot to enter an intermittent standby mode.

[0017] As a preferred embodiment of this application, the specific method for determining whether the heat pipes in each of the sealed convection cavities are in a phase change saturation state is as follows: The controller calculates the rate of temperature change of each of the temperature sensors within a preset time period. When any of the real-time temperature values ​​exceeds the corresponding preset safe temperature threshold and the rate of temperature change is greater than the preset rate threshold, the controller determines that the corresponding heat pipe is in a phase change saturation state.

[0018] This application provides a passive heat dissipation device and thermal management control method for a cleanroom cleaning robot. By attaching heat-generating components of the cleaning robot to the inner shell using heat conductors, the heat generated by each component is conducted to the aluminum alloy inner shell via the heat conductors. Then, the heat is transferred to the outer shell through natural convection of air in the sealed convection cavity between the inner and outer shells. Finally, the heat is dissipated into the workshop environment by the outer shell through natural convection and thermal radiation, achieving a fully enclosed passive heat dissipation system without a fan. Simultaneously, when the temperature of the heat pipes in the sealed cavity rises to the phase change point, a gas-liquid phase change occurs. The liquid working fluid inside the heat pipe absorbs heat through vaporization, temporarily storing the instantaneous heat generated by short-term high loads as latent heat of vaporization within the working fluid. After the load decreases, the latent heat of condensation is slowly released to the outside through the pipe wall. The liquid heat pipe achieves temporary heat storage and slow release through the natural convection circulation of the internal heat-conducting liquid. This significantly reduces the temperature rise rate of the control module, drive boards, and battery modules when the robot moves rapidly or the robotic arm is operating at full load, suppressing the temperature peak below the safety limit. Thus, without relying on any active heat dissipation methods, the requirements of cleanrooms for no particle release and no airflow disturbance are met. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of a passive heat dissipation device for a cleanroom cleaning robot according to one embodiment of this application; Figure 2 This is a cross-sectional view of a passive heat dissipation device for a cleanroom cleaning robot according to one embodiment of this application; Figure 3 This is a flowchart illustrating the steps of a thermal management control method in a passive heat dissipation device for a cleanroom cleaning robot according to an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 1. Automated Guided Vehicle; 2. Lifting Components; 3. Multi-DOF Robotic Arm; 4. Mop Holder; 5. Mop; 6. Double-Layer Housing; 7. Control Box; 21. First linear motion module; 22. Mounting plate; 23. Second linear motion module. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] Furthermore, descriptions using terms such as "first" and "second" in this application are for descriptive purposes only (e.g., to distinguish identical or similar elements) and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, technical solutions from different embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, such a combination should be considered nonexistent and not within the scope of protection claimed in this application.

[0023] Please refer to Figure 1 , Figure 2In the first embodiment, the cleanroom cleaning robot includes an automated guided vehicle (AGV) 1, a control box 7, a lifting assembly 2, and a multi-degree-of-freedom robotic arm 3. The AAV 1 serves as the robot's mobile chassis, carrying various functional components and autonomously moving along a preset path within the cleanroom. The control box 7 is fixed above the AAV 1 and contains a control module and a driving drive plate. The control module executes core algorithms such as path planning and motion control, while the driving drive plate drives the wheelset of the AAV 1.

[0024] The lifting assembly 2 is located at the front end of the automated guided vehicle 1. The lifting assembly 2 includes a first linear motion module 21, a mounting plate 22, and a second linear motion module 23. The first linear motion module 21 is vertically fixed on the automated guided vehicle 1, and its output end is connected to the mounting plate 22 to drive the mounting plate 22 to move up and down in the vertical direction. The second linear motion module 23 is fixed on the mounting plate 22, and its output end is connected to the base of the multi-degree-of-freedom robotic arm 3. Through the linkage between the first linear motion module 21 and the second linear motion module 23, the position of the multi-degree-of-freedom robotic arm 3 can be adjusted in the vertical direction to adapt to surfaces to be cleaned at different heights and positions.

[0025] The automated guided vehicle (AGV) is equipped with multiple mop compartments 4, divided into cleaning and recycling compartments. The cleaning compartments contain orderly stacked mops. The multi-degree-of-freedom robotic arm 3 is a six-axis articulated robotic arm with grippers at its end. These grippers are used to pick up the mops 5 from the mop compartments and to remove used mops and place them in the recycling compartment. Each joint of the multi-degree-of-freedom robotic arm 3 has a joint drive plate to drive the servo motor of the corresponding joint, enabling the robotic arm's multi-degree-of-freedom movement. During wiping operations, the control module sends motion commands to each joint drive plate according to a preset cleaning path, driving the multi-degree-of-freedom robotic arm 3 to move the mops 5 along a predetermined trajectory and with pressure to wipe the workshop walls, floors, or equipment surfaces. Simultaneously, the AGV 1 moves along the planned path, achieving cleaning of the entire cleanroom.

[0026] The passive heat dissipation device for the cleanroom cleaning robot provided in this embodiment is a fanless, fully enclosed structure, comprising multiple sets of double-layer shells 6, heat conductors, and heat pipes. Each set of double-layer shells 6 includes an inner shell and an outer shell, with a sealed convection cavity between the inner and outer shells. Multiple sets of double-layer shells 6 are respectively disposed on the outer wall of the control box 7, the outer wall of the bottom cavity of the automated guided vehicle 1, the outer wall of the fixed portion of the lifting assembly 2, and the outer wall of the base of each joint of the multi-degree-of-freedom robotic arm 3. This arrangement ensures that each heat-generating component is enclosed by the double-layer shells 6 to form an independent heat dissipation unit, without interfering with the normal movement of the lifting assembly 2 and the multi-degree-of-freedom robotic arm 3.

[0027] Furthermore, the control module, walking drive board, lifting drive board, joint drive boards and battery module are all fixed to the inner wall of the inner shell of the corresponding double shell 6, and form a heat conduction connection with the inner shell through a heat conductor; the heat conduction pipe fills each sealed convection cavity and at least covers part of the outer wall of the inner shell, and the air in each sealed convection cavity forms a natural convection heat transfer between the inner shell and the outer shell. In this embodiment, the heat conduction pipe is a gas-liquid phase change heat conduction pipe or a liquid heat conduction pipe.

[0028] During operation, the cleaning robot generates Joule heat from its control module, walking drive board, lifting drive board, joint drive boards, and battery module. For ease of description, these components are collectively referred to as the heat-generating parts. Since each heat-generating part is connected to the inner wall of the inner shell via a heat conductor, heat is first conducted to the inner shell through the heat conductor.

[0029] In this embodiment, the heat conductor is a thermally conductive pad, which is sandwiched between each heat-generating component and the inner wall of the corresponding inner shell. Its good flexibility fills the microscopic interface gap between the two, reducing contact thermal resistance. The thermally conductive pad is a soft thermally conductive interface material composed of silicone as the base material and thermally conductive fillers such as alumina or boron nitride, with a thickness of 1mm to 3mm.

[0030] In other embodiments, the heat conductor may also be a layer of thermally conductive silicone grease coated between the heat-generating component and the inner shell, or a metal heat-conducting block made of aluminum alloy. The selection of the heat conductor can be determined based on the space dimensions and heat generation of the specific installation location: for components with small gaps and requiring repeated disassembly and maintenance, such as control modules and battery modules, thermal pads are preferred; for components with larger gaps and permanently fixed, such as joint drive boards, metal heat-conducting blocks can be used to obtain lower thermal resistance.

[0031] As another implementation of the heatsink, the heatsink can adopt a three-layer composite structure, including a thermally conductive interface layer, a heat spreader layer, and a thermally conductive adhesive layer stacked sequentially. The thermally conductive interface layer is a thermally conductive silicone grease layer or a thermally conductive pad, with a thickness of 0.05mm to 0.5mm, and is attached to the surface of the heat-generating component. The heat spreader layer is a vacuum chamber heat spreader or a graphite heat spreader sheet, with a thickness of 0.2mm to 0.8mm, sandwiched between the thermally conductive interface layer and the thermally conductive adhesive layer. The thermally conductive adhesive layer is a thermally conductive double-sided adhesive tape or a thermally conductive structural adhesive, and is attached to the inner wall of the inner shell. The heat spreader layer rapidly diffuses heat from localized hot spots on the surface of the heat-generating component laterally, allowing heat to be transferred more evenly to the inner shell, making it suitable for heat dissipation of high-power-density components such as control modules.

[0032] The heat generated by the heating element is conducted to the inner shell via a heat conductor, causing the overall temperature of the inner shell to rise. The outer wall surface facing the sealed convection cavity serves as a heat exchange surface, transferring heat to the air layer in direct contact with the wall through thermal conduction, thus raising the temperature of that air layer. Since the airflow within the sealed convection cavity is undisturbed by external forced airflow, the heated air relies on its own density change to create natural buoyancy, driving continuous air circulation within the cavity. The heated air decreases in density and rises, releasing heat upon reaching the inner wall of the outer shell. After cooling, its density increases and it sinks, forming a continuous natural convection cycle within the sealed convection cavity. Through this cycle, heat is continuously transferred from the inner shell to the outer shell.

[0033] It is understandable that, in order to optimize the heat transfer efficiency of natural convection, the gap width of the sealed convection cavity is set to 5mm~12mm. When the gap width is less than 5mm, air flow is restricted, and natural convection is difficult to establish effectively; when the gap width is greater than 12mm, the buoyancy is insufficient to drive the air to form a stable circulation flow, and the heat transfer efficiency actually decreases.

[0034] Furthermore, under conditions of rapid robot movement or heavy-duty robotic arm operations, the heat generation rate of the heating components may temporarily exceed the steady-state heat dissipation capacity of the outer casing. In this situation, the heat pipe filled within the sealed convection cavity comes into play. When a gas-liquid phase change heat pipe is used, it contains a phase change working fluid that undergoes a gas-liquid phase change upon heating and absorbs a large amount of latent heat of vaporization. When a liquid heat pipe is used, it contains a heat-conducting liquid that transfers heat through convection circulation upon heating, similarly achieving effective thermal buffering. Taking a gas-liquid phase change heat pipe as an example, the heat pipe consists of a metal shell and a phase change working fluid encapsulated inside the shell. The phase change working fluid can be any one of deionized water, ethanol, or acetone, with its boiling point or phase change temperature set between 45℃ and 65℃. When the temperature inside the sealed convection cavity rises to the phase change temperature, the liquid working fluid absorbs heat and vaporizes, storing a large amount of latent heat as heat of vaporization. This maintains the temperature inside the cavity near the phase change point, thus suppressing temperature spikes in the heating components. When the robot's load decreases or it stops for standby, the vaporized working fluid inside the gas-liquid phase change heat pipe condenses back into a liquid as the temperature drops. It then slowly releases its latent heat of condensation to the external environment through the pipe wall, restoring its heat storage capacity so it can be used again during the next high-load operation.

[0035] After absorbing heat from the hot air and phase change material inside the cavity, the outer shell's temperature rises. Since the cleanroom environment is typically maintained at 18℃~22℃, there is a sufficient temperature difference between the outer shell surface and the cleanroom environment, allowing heat to dissipate to the external environment through both natural convection and thermal radiation.

[0036] In this embodiment, the inner shell is made of aluminum alloy, such as 6061 or 6063 aluminum alloy. Aluminum alloy has a high thermal conductivity, which can quickly and evenly diffuse the heat from the heating components to the entire shell surface. The outer shell is made of SUS316L stainless steel, which has good corrosion resistance and can withstand the hydrogen peroxide vaporization disinfection and surface wiping commonly used in cleanrooms, ensuring that the equipment will not corrode or fail during long-term use in a strong oxidizing disinfection environment. The outer shell of the double-layer shell 6 containing the battery module is composed of a SUS316L stainless steel outer shell and a flame-retardant engineering plastic inner lining, which meets both explosion-proof safety requirements and can withstand disinfectant wiping. The charging contacts of the battery module are provided with a gold-plated layer with a thickness of not less than 1μm to ensure that the contact resistance does not increase during long-term use in a strong oxidizing environment.

[0037] Sealing components are provided at the joints of the sheet metal within the double-layer shell 6, as well as at the assembly gaps between the double-layer shell 6 and other components. These sealing components include sealing gaskets and miniature fluororubber sealing rings. The sealing gaskets are made of fluoroplastic. They are placed at the joints of the sheet metal within each double-layer shell 6 to seal these gaps. The miniature fluororubber sealing rings are placed at the assembly gaps between the inner wall of each double-layer shell 6 and the outer wall of the control box 7, the outer wall of the lifting assembly 2, and the outer walls of the joints of the multi-degree-of-freedom robotic arm 3 to seal these gaps. Fluororubber material possesses excellent oxidation resistance and high-temperature resistance, enabling it to withstand the hydrogen peroxide disinfection environment of a cleanroom, while maintaining elasticity during long-term use to ensure reliable sealing.

[0038] To further meet the stringent electromagnetic compatibility requirements of cleanrooms, this embodiment also includes an electromagnetic shielding assembly. The electromagnetic shielding assembly includes a conductive shielding layer, conductive sealing gaskets, and shielding rings. The conductive shielding layer is a conductive silver paste coating or a chemically plated nickel layer, attached to the inner and outer surfaces of each double-layered housing 6. The conductive sealing gaskets are pressed into the joints of each double-layered housing 6 and into the assembly gaps between them. Both sides of each conductive sealing gasket are in contact with the adjacent conductive shielding layer, eliminating electromagnetic leakage at the gaps. Shielding rings are fitted onto the cable inlets and outlets of each double-layered housing 6, with the outer edge of each ring overlapping and conducting with the conductive shielding layer to prevent electromagnetic waves from leaking along cable holes. Each double-layered housing 6 is connected to the robot's grounding terminal via grounding studs and grounding wires, forming a continuous closed electromagnetic shield that effectively suppresses electromagnetic radiation leakage from the internal drive board and control module, preventing interference with precision production equipment within the cleanroom.

[0039] In this embodiment, the cleanroom cleaning robot is also equipped with a controller and multiple temperature sensors. The controller is located inside the control box 7. Multiple temperature sensors are respectively installed on the surface of the control module, the walking drive plate, the lifting drive plate, each joint drive plate, and the battery module. Each temperature sensor is communicatively connected to the controller to collect the temperature of each heat-generating component in real time and send the temperature value to the controller.

[0040] This embodiment also provides a thermal management control method for a passive heat dissipation device of a cleanroom cleaning robot, including the following steps: S1. Temperature sensors collect the real-time temperatures of the control module, walking drive board, lifting drive board, each joint drive board and battery module, and send the collected real-time temperature values ​​to the controller. S2. The controller compares each real-time temperature value with the corresponding preset safe temperature threshold. S3. When any real-time temperature value exceeds the corresponding preset safe temperature threshold, the controller gradually reduces the moving speed of the automated guided vehicle 1 and / or the load of the multi-degree-of-freedom robotic arm 3 until each real-time temperature value falls back below the corresponding preset safe temperature threshold. S4. The controller determines whether the heat pipes in each sealed convection cavity are saturated based on the rate of change of each real-time temperature value. S5. When the controller determines that any heat pipe is in a phase change saturation state and the corresponding real-time temperature value continues to rise, the controller controls the robot to enter an intermittent standby mode, suspends operation and maintains the monitoring of each temperature sensor.

[0041] S6. When each real-time temperature value falls below the corresponding preset safe temperature threshold, and each heat pipe completes condensation and heat release, the controller controls the robot to resume normal operation.

[0042] It is understandable that in step S2, different heat-generating components have different preset safe temperature thresholds. For example, the chip of the control module can withstand 85°C, while the safe temperature of the battery module generally does not exceed 60°C. Setting the threshold independently is more in line with the actual temperature resistance characteristics of each component.

[0043] The step-by-step reduction in step S3 is as follows: the moving speed of the automated guided vehicle 1 is reduced step-by-step by a preset percentage, and the output torque of each joint drive plate of the multi-degree-of-freedom robotic arm 3 is reduced step-by-step by a preset percentage. The moving speed of the automated guided vehicle 1 is reduced by 5% to 20% per step, and the output torque of each joint drive plate of the multi-degree-of-freedom robotic arm 3 is reduced by 5% to 20% per step.

[0044] In step S4, the specific determination method is as follows: the controller calculates the temperature change rate of each temperature sensor within a preset time period. When any real-time temperature value exceeds the corresponding preset safe temperature threshold and the temperature change rate is greater than the preset rate threshold, the controller determines that the corresponding heat pipe is in a phase change saturation state. For gas-liquid phase change heat pipes, phase change saturation means that the liquid working fluid inside has been completely vaporized and has lost the ability to continue absorbing latent heat of vaporization. For liquid heat pipes, phase change saturation means that the temperature of the heat-conducting liquid has risen to close to the temperature of the outer shell, and the driving force of convective heat transfer has been significantly weakened. If the heating element continues to generate heat at this time, the temperature will rise rapidly without inhibition, and more proactive protection measures must be taken. In the standby mode in step S5, the controller controls the automated guided vehicle 1 to stop moving and controls the multi-degree-of-freedom robotic arm 3 to stop moving, while the temperature sensor keeps collecting the real-time temperature of each heat-generating component.

[0045] In step S6, before resuming normal operation, the controller continuously receives real-time temperature values ​​collected by each temperature sensor. When each real-time temperature value is lower than the corresponding preset safe temperature threshold and the duration reaches the preset recovery time, the controller controls the robot to exit the standby mode and resume normal operation, so as to avoid repeated overheating protection caused by the temperature immediately recovering after it drops.

[0046] Furthermore, the preset safety temperature thresholds include a first temperature threshold and a second temperature threshold, with the second temperature threshold being higher than the first temperature threshold. When the real-time temperature value exceeds the first temperature threshold but does not exceed the second temperature threshold, the controller reduces the moving speed of the automated guided vehicle 1. When the real-time temperature value exceeds the second temperature threshold, the controller simultaneously reduces the moving speed of the automated guided vehicle 1 and the load on the multi-degree-of-freedom robotic arm 3, and controls the robot to enter an intermittent standby mode. By setting the first and second temperature thresholds to form a graded protection mechanism, when the temperature is between the first and second thresholds, only the speed is reduced, which can avoid triggering standby due to slight overheating and affecting the continuity of cleaning operations. When the temperature exceeds the second threshold, it is determined that the passive heat dissipation capacity is insufficient, and multiple protection actions of speed reduction, load reduction, and standby are immediately executed, effectively preventing the heat-generating components from continuing to heat up to the critical point of damage.

[0047] This application achieves fanless, fully enclosed passive cooling by attaching the heat-generating components of the cleaning robot to the inner shell using heat conductors. The heat generated by each component is conducted to the aluminum alloy inner shell via the heat conductors, and then transferred to the outer shell via natural convection through the sealed convection cavity between the inner and outer shells. Finally, the heat is dissipated into the workshop environment by the outer shell through natural convection and thermal radiation. Since the entire machine has no rotating parts, it avoids the generation of submicron particles from bearing wear and fan blade rotation, as well as directional airflow blowing out of the shell. Therefore, it neither increases the concentration of suspended particles in the workshop nor disturbs the existing unidirectional flow field, avoiding eddies and backflow of pollutants caused by turbulent flow. Meanwhile, when the temperature of the heat pipe inside the sealed cavity rises to the phase change point, the liquid working fluid inside the gas-liquid phase change heat pipe vaporizes and absorbs heat, temporarily storing the instantaneous heat generated by the short-term high load in the form of latent heat of vaporization inside the working fluid. After the load decreases, the latent heat of condensation is slowly released to the outside through the pipe wall. The liquid heat pipe achieves temporary heat storage and slow release through the natural convection circulation of the internal heat-conducting liquid, which significantly reduces the temperature rise rate of the control module, each drive board and battery module when the robot moves quickly or the robotic arm is fully loaded. The temperature peak is suppressed below the safety limit. Thus, without the aid of any active heat dissipation means, it simultaneously meets the cleanroom's access requirements for no particle release and no airflow disturbance as well as the equipment's own thermal reliability requirements.

[0048] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0049] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A passive heat dissipation device for a cleanroom cleaning robot, applied to a cleanroom cleaning robot, characterized in that, The cleanroom cleaning robot includes an automated guided vehicle, a control box, a lifting assembly, and a multi-degree-of-freedom robotic arm; the control box contains a control module and a walking drive plate, the lifting assembly contains a lifting drive plate, each joint of the multi-degree-of-freedom robotic arm contains a joint drive plate, and the bottom cavity of the automated guided vehicle contains a battery module. The passive heat dissipation device is a fanless, fully enclosed structure, comprising multiple sets of double-layer shells, heat conductors, and heat pipes. Each set of double-layer shells includes an inner shell and an outer shell, with a sealed convection cavity provided between the inner shell and the outer shell. Multiple sets of the double-layered shells respectively cover the control box, the bottom cavity of the automated guided vehicle, the lifting assembly, and each joint of the multi-degree-of-freedom robotic arm; The control module, walking drive board, lifting drive board, joint drive board and the battery module are all fixed to the inner shell corresponding to the double shell, and form a thermal conduction connection with the inner shell through the heat conductor; The heat pipes fill each of the sealed convection cavities and at least cover a portion of the outer wall of the inner shell.

2. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, It also includes an electromagnetic shielding assembly; the electromagnetic shielding assembly includes a conductive shielding layer for the housing, a conductive sealing gasket, and a shielding cable ring; The conductive shielding layer of the housing is attached to the inner and outer surfaces of each set of double-layer housings; The conductive sealing gasket is pressed into the splicing gap of each of the double-layer shells and the assembly gap between each of the double-layer shells, and the two sides of each conductive sealing gasket are respectively in contact with the conductive shielding layer of the adjacent shell. The shielding rings are sleeved at the cable inlet and outlet of each of the double-layer shells, and the outer edge of each shielding ring overlaps and communicates with the conductive shielding layer of the shell. Each of the aforementioned double-layered shells is connected to the robot's grounding terminal via a conductive connector.

3. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, It also includes a sealing assembly; the sealing assembly includes a sealing gasket and a miniature fluororubber sealing ring; The sealing gasket is disposed at the joint gap of the plates of each of the double-layer shells to seal the joint gap; The miniature fluororubber sealing ring is disposed at the assembly gap formed by the contact between each of the double-layer shells and the outer wall of the control box, the outer wall of the lifting assembly, and the outer wall of each joint of the multi-degree-of-freedom robotic arm, and is used to seal the assembly gap.

4. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, The heat conductor is any one or more combinations of a thermal pad, a thermal grease layer, or a metal thermal block, and the heat conductor is sandwiched between the control module, the walking drive plate, the lifting drive plate, each of the joint drive plates, the battery module, and the inner wall of the corresponding inner shell.

5. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, The heat conductor includes a thermally conductive interface layer, a heat spreader layer, and a thermally conductive adhesive layer stacked sequentially. The thermally conductive interface layer is attached to the surface of the control module, the walking drive plate, the lifting drive plate, each of the joint drive plates, and the battery module. The heat spreader layer is sandwiched between the thermally conductive interface layer and the thermally conductive adhesive layer. The thermally conductive adhesive layer is attached to the inner wall of the inner shell.

6. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, The outer shell of the double-layer housing containing the battery module is made of stainless steel and flame-retardant engineering plastic composite. The charging contacts of the battery module are provided with a gold-plated layer. The inner shell is made of aluminum alloy and the outer shell is made of stainless steel.

7. The passive heat dissipation device for a cleanroom cleaning robot according to claim 1, characterized in that, The cleanroom cleaning robot is also equipped with a controller and multiple temperature sensors; The controller is located inside the control box; Multiple temperature sensors are respectively disposed on the surface of the control module, the walking drive board, the lifting drive board, each of the joint drive boards and the battery module, and each temperature sensor is communicatively connected to the controller.

8. A thermal management control method for a passive heat dissipation device for a cleanroom cleaning robot, applicable to the passive heat dissipation device for a cleanroom cleaning robot as described in any one of claims 1-7, characterized in that, Includes the following steps: The temperature sensors collect the real-time temperatures of the control module, the walking drive board, the lifting drive board, each of the joint drive boards, and the battery module, and send the collected real-time temperature values ​​to the controller. The controller compares each of the real-time temperature values ​​with the corresponding preset safe temperature threshold. When any of the real-time temperature values ​​exceeds the corresponding preset safety temperature threshold, the controller gradually reduces the moving speed of the automated guided vehicle and / or the load of the multi-degree-of-freedom robotic arm until each of the real-time temperature values ​​falls back below the corresponding preset safety temperature threshold. The controller determines whether the heat pipes in each of the sealed convection cavities are in a phase change saturation state based on the rate of change of each of the real-time temperature values. When the controller determines that any of the heat pipes is in a phase change saturation state and the corresponding real-time temperature value continues to rise, the controller controls the robot to enter an intermittent standby mode, suspends operation and maintains the monitoring of each of the temperature sensors; When each of the real-time temperature values ​​falls below the corresponding preset safe temperature threshold, and each of the heat pipes completes condensation and heat release, the controller controls the robot to resume normal operation.

9. The thermal management control method for a passive heat dissipation device for a cleanroom cleaning robot according to claim 8, characterized in that, The preset safe temperature threshold includes a first temperature threshold and a second temperature threshold, wherein the second temperature threshold is higher than the first temperature threshold. When the real-time temperature value exceeds the first temperature threshold but does not exceed the second temperature threshold, the controller reduces the moving speed of the automated guided vehicle. When the real-time temperature value exceeds the second temperature threshold, the controller simultaneously reduces the moving speed of the automated guided vehicle and the load of the multi-degree-of-freedom robotic arm, and controls the robot to enter an intermittent standby mode.

10. The thermal management control method for a passive heat dissipation device for a cleanroom cleaning robot according to claim 8, characterized in that, The specific method for determining whether the heat pipes in each of the aforementioned sealed convection cavities are in a phase change saturation state is as follows: The controller calculates the temperature change rate of each temperature sensor within a preset time period. When any real-time temperature value exceeds the corresponding preset safe temperature threshold and the temperature change rate is greater than the preset rate threshold, the controller determines that the corresponding heat pipe is in a phase change saturation state.

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