Resin sand casting energy-saving and environment-friendly surface treatment method and system based on dip-coating process

Abstract

The invention discloses an energy-saving and environment-friendly surface treatment method and system for resin sand casting based on a dip-coating process, and relates to the field of resin sand casting, the surface treatment method is based on a surface treatment device, the surface treatment device comprises a dip-coating frame and a filter screen, and the surface treatment method comprises the following steps: S1, preparing a water-based environment-friendly coating; s2, intelligent dip-coating treatment; s3, gradient drying; and S4, recycling the coating. According to the invention, water-based environment-friendly paint is adopted, VOC emission of solvent-free paint is not contained, a paint circulating system is matched, waste pollution is reduced, a gradient drying process integrates casting waste heat recovery and auxiliary heating, low-temperature, medium-temperature and high-temperature staged temperature control, and energy waste is avoided; the negative pressure adsorption and intelligent dip-coating technology reduces excessive use of paint, reduces material loss, monitors the thickness of the coating in real time, solves the problem of coating blind areas of complex structures such as deep cavities and bosses, and improves the uniformity of the coating.

Description

Technical Field

[0001] The present invention relates to the technical field of resin sand casting, in particular to an energy-saving and environment-friendly surface treatment method and system for resin sand casting based on a dipping process. Background Art

[0002] Resin sand refers to molding sand or core sand that uses artificial synthetic resin as a binder for sand particles. After the resin sand is used to make a mold or core, the resin undergoes an irreversible cross-linking reaction and solidifies through the action of a curing (hardening) agent, thereby giving the mold or core the necessary strength.

[0003] For example, the preparation method of the resin sand mold disclosed in the publication number CN109290516A includes the following steps: (1) weighing quartz sand, resin and hardener, adding them into a mixer and stirring to mix them evenly, then pouring them into a mold, standing them at room temperature to form them, and drying them to obtain a semi-finished resin sand mold; (2) dipping, placing the semi-finished resin sand mold obtained in step (1) into a casting coating for dipping, and drying them at a temperature of 60 to 80° C. after the dipping is completed, thereby obtaining the resin sand mold.

[0004] In the prior art, during surface treatment of resin sand molds, due to the variable shapes of resin sand molds, for sand molds with complex structures such as deep cavities, bosses, and narrow slits, not only are coating blind areas, flow marks, and bubbles prone to occur, resulting in rough casting surfaces and sand sticking, but it is also difficult to adjust the coating thickness. In the drying process, improper temperature control often causes coating cracking and adhesive failure, affecting the quality of the casting. Summary of the Invention

[0005] The purpose of the present invention is to provide an energy-saving and environmentally friendly surface treatment method and system for resin sand casting based on a dip coating process, so as to solve the problem raised in the above-mentioned background technology that for sand molds with complex structures such as deep cavities, bosses, and narrow gaps, not only are coating blind areas, flow marks, and bubbles prone to occur, but it is also difficult to adjust the coating thickness, which affects the quality of the casting.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: an energy-saving and environmentally friendly surface treatment method and system for resin sand casting based on a dip coating process. The surface treatment method is based on a surface treatment device, which includes a dip coating frame and a filter screen. The surface treatment method includes the following steps: S1. Preparation of water-based environmentally friendly coating: Weighing and mixing coating raw materials to prepare water-based environmentally friendly coating; The water-based environmentally friendly coating raw materials include the following components according to weight percentage: 60% to 70% diatomaceous earth-based aggregate, 5% to 8% sodium bentonite, 10% to 15% water-based resin binder, 25% to 50% deionized water, and 0.1% to 0.3% nano titanium dioxide; S2, intelligent dipping process: the resin sand mold is sent into the dipping frame for dipping, and the coating thickness is monitored in real time for regulation; S3, gradient drying: decompose and control the temperature and time, volatilize the moisture in the coating, and solidify the binder; S4. Paint recycling: The paint in the dipping frame passes through a filter to remove large particles of impurities, and the filtered paint flows back to the dipping frame for reuse.

[0007] Preferably, in step S1, the preparation of the water-based environmentally friendly coating comprises the following steps: S11, pre-mixing of raw materials: adding diatomaceous earth-based aggregate, sodium bentonite and deionized water into a stirring container, stirring at a speed of 300-500 rpm for 5 minutes to form a uniform slurry; S12, nanomaterial addition: add nano titanium dioxide to the uniform slurry, start the high-speed disperser and stir for 10 minutes; S13, binder mixing: add water-based resin binder and stir for 15 minutes to form a low-viscosity water-based environmentally friendly coating.

[0008] Preferably, in step S2, the intelligent dip coating process comprises the following steps: S21, immersion control: clamp the resin sand mold, immerse the sand mold into the dipping frame, and adjust the immersion angle at the same time; S22, negative pressure adsorption: After the resin sand mold is completely immersed in the coating, the negative pressure adsorption device is turned on and the infrared thickness sensor monitors the coating thickness on the sand mold surface; S23, thickness adjustment: compare and analyze the received coating thickness data with the preset standard, issue instructions based on the coating thickness results, and adjust the coating thickness.

[0009] Preferably, in step S23, thickness adjustment includes the following steps: A1. Obtain the data collected by the infrared thickness sensor and process the collected data; A2. Determine the preset coating thickness standard, compare the real-time thickness data with the preset threshold, and calculate the average thickness deviation Δh and regional thickness uniformity index; A3. Determine the coating thickness based on the average thickness deviation, trigger the adjustment strategy, and adjust the coating parameters; A4. After the adjustment strategy is implemented, the sensor continues to collect data to verify whether the coating thickness falls within the target range.

[0010] Preferably, in step S3, the gradient drying comprises the following steps: S31, dripping treatment: lift the resin sand mold after dipping from the dipping frame, and accelerate the dripping of excess coating on the sand mold surface through micro-vibration; S32, low-temperature free water removal: using the waste heat from the foundry, the air is heated to 80°C through a plate heat exchanger to remove free water from the coating; S33, medium temperature removal of bound water: using infrared radiation heating, directional heating is carried out in the deep part of the sand mold cavity to remove the bound water adsorbed between the aggregate and the binder in the coating; S34, high temperature curing binder: mainly using the residual heat from casting, supplemented by electric heating compensation, to completely cure the water-based resin binder to form a dense high temperature resistant coating; S35, cooling and taking out of the oven: After the drying is completed, turn off the heating source and let it cool naturally. Open the oven door when the oven temperature drops below 60℃.

[0011] Preferably, in step S35, the resin sand mold that has been cooled and taken out of the furnace is visually inspected to check the surface condition of the coating, and the coating thickness is randomly inspected by an electromagnetic induction thickness gauge.

[0012] A resin sand casting energy-saving and environmentally friendly surface treatment system based on a dipping process. The surface treatment device also includes a closed cabin and an outer shell. The dipping frame is fixedly connected to the inner side of the closed cabin. A clamping mechanism is provided above the dipping frame. The clamping mechanism is installed on the inner side of the closed cabin. A VOC adsorption mechanism is installed on the top side of the closed cabin. The VOC adsorption mechanism absorbs VOC components released by the coating through activated carbon + catalytic combustion.

[0013] Preferably, a filter is installed on the inner side of the dipping frame, and a circulation mechanism is installed on the outer side of the dipping frame. One end of the circulation mechanism is connected to the bottom side of the dipping frame, and the circulation mechanism is used to recycle the paint.

[0014] Preferably, a conveying member is installed inside the outer shell, a drying mechanism is fixedly connected to the top of the outer shell, and two sides of the outer shell are respectively connected to the two switch mechanisms.

[0015] Preferably, a temperature sensor is fixedly connected to one side of the outer shell, and the temperature sensor is used to monitor the drying temperature inside the outer shell.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, water-based environmentally friendly paint is used, which is mainly composed of natural materials such as diatomaceous earth-based aggregate and sodium-based bentonite. Nano-titanium dioxide is added to improve the coating performance. It does not contain VOC emissions of solvent-based paint. It is combined with a paint circulation system to reduce waste pollution and meet the requirements of green casting. The gradient drying process integrates casting waste heat recovery and solar auxiliary heating, and controls the temperature in stages of low, medium and high temperatures to avoid energy waste; negative pressure adsorption and intelligent dipping technology reduce excessive use of paint and reduce material loss. The coating thickness is monitored in real time through the control system. Combined with negative pressure adsorption and adjustable dipping angle, it solves the coating blind spots of complex structures such as deep cavities and bosses, improves coating uniformity, improves high-temperature erosion resistance by 20%, and reduces the surface roughness of castings by 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of an energy-saving and environmentally friendly surface treatment method for resin sand casting based on a dip-coating process of the present invention; Figure 2 This is a first three-dimensional structural schematic diagram of an energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dip-coating process according to the present invention; Figure 3 This is a second three-dimensional structural schematic diagram of an energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dip-coating process according to the present invention; Figure 4 This is a schematic diagram of the internal structure of a closed cabin of an energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dip-coating process according to the present invention; Figure 5 This is a schematic diagram of the connection structure of a dipping frame of an energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dipping process of the present invention; Figure 6 This is a schematic diagram of the outer shell connection structure of an energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dip-coating process of the present invention.

[0018] In the figure: 1. Enclosed cabin; 2. Outer shell; 3. Conveying part; 4. Drying mechanism; 5. Switching mechanism; 6. VOC adsorption mechanism; 7. Dipping frame; 8. Clamping mechanism; 9. Circulation mechanism; 10. Filter; 11. Temperature sensor. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the implementation regulations described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1: Reference Figure 1Shown: An energy-saving and environmentally friendly surface treatment method for resin sand casting based on a dip-coating process, which aims to solve the problems of uneven coating, difficult thickness control, and drying quality in the surface treatment of complex structure resin sand molds. Technical Solution

[0021] 1. Preparation of Water-Based Environmentally Friendly Coating (Step S1) Premixing: Mix diatomaceous earth-based aggregate, sodium bentonite and deionized water at 300 rpm for 5 minutes to form a uniform slurry.

[0022] Nano-dispersion: Add nano-titanium dioxide and stir in a high-speed disperser for 10 minutes to avoid particle agglomeration.

[0023] Binder mixing: Add water-based resin binder and stir at low speed for 15 minutes to form a low viscosity coating.

[0024] Core advantages: Mainly composed of natural minerals and water-based binders, it is VOC-free and environmentally friendly; nano-titanium dioxide improves the coating's high temperature resistance and uniformity.

[0025] 2. Smart Dip Coating Process (Step S2) Processing flow: Immersion control: Clamp the sand mold and immerse it into the dipping frame at an adjustable angle (such as tilted / vertical) at a speed of 1cm / s to cover complex structures such as deep cavities and bosses.

[0026] Negative pressure adsorption: After the sand mold is completely immersed, turn on the negative pressure device (-0.05MPa) and monitor the coating thickness in real time through the infrared thickness sensor (10 groups / second).

[0027] Thickness adjustment: Compare the real-time thickness with the preset standard and calculate the average deviation (Δh) and uniformity index.

[0028] If the thickness is insufficient, extend the dipping time or increase the negative pressure; if it is too thick, reduce the time or reduce the negative pressure to ensure uniform coating (deviation ≤ ±5% of target thickness).

[0029] Key technologies: Negative pressure adsorption enhances coating adhesion, and adjustable immersion angle eliminates blind spots; real-time closed-loop control enables precise thickness adjustment.

[0030] 3. Gradient Drying Process (Step S3) Staged control: Drip treatment: Micro vibration (20Hz) accelerates the dripping of excess paint to avoid sagging and bubbles.

[0031] Low-temperature free water removal (80°C): Utilize the waste heat from casting (plate heat exchanger), heat up at 5°C / min, ventilation volume 100m³ / h・m², and use a dehumidification valve to control humidity to <60%RH to prevent surface cracking.

[0032] Medium temperature removal of bound water (120°C): Infrared radiation heating (wavelength 2μm) is used to directionally heat the deep part of the cavity, with a temperature increase of 3°C / minute. Dry nitrogen (purity ≥99.9%) is introduced to inhibit oxidation and remove bound water between the aggregate and the binder.

[0033] High temperature curing adhesive (150°C): mainly based on casting waste heat, compensated by electric heating, constant temperature for 10 minutes, horizontal air circulation (0.5m / s) to ensure uniform curing, over-temperature interlock device to ensure safety.

[0034] Cooling and taking out of the oven: Cool naturally to below 60℃, visually inspect the surface condition, and use electromagnetic induction thickness gauge to check the thickness.

[0035] Principle: Remove moisture in stages (free water → bound water) to avoid cracking of the coating caused by sudden temperature changes, while gradually activating the binder cross-linking reaction to form a dense coating.

[0036] 4. Paint recycling (step S4) Process: The paint in the dipping frame passes through the filter (to remove large particles of impurities) and then flows back to the dipping frame through the circulation mechanism. New paint is added regularly to maintain the stability of the composition.

[0037] Advantages: Reduce waste emissions, reduce material loss, and meet energy-saving and environmental protection requirements.

[0038] 2. Technical Principle 1. Principle of complex structure coating Adjustable angle immersion: For structures such as deep cavities and narrow gaps, through inclined or vertical immersion, gravity and paint fluidity are used to fill blind areas, avoiding the dead angle problem of traditional dipping.

[0039] Negative pressure adsorption assist: The negative pressure environment increases the adhesion of the coating to the sand mold surface, especially on vertical surfaces such as bosses, reducing flow marks and bubbles caused by surface tension.

[0040] 2. Coating thickness control principle Real-time feedback of infrared thickness measurement: High-frequency collection of coating thickness data, processing of abnormal values, calculation of regional uniformity, and formation of a “monitoring-analysis-adjustment” closed-loop control.

[0041] Parameter linkage adjustment: first adjust the dipping time (affects the amount of coating adhesion), then adjust the negative pressure (affects the adsorption force) to ensure that the thickness is accurately met.

[0042] 3. Gradient drying principle Moisture is removed in steps: in the low-temperature stage (80°C), free water on the surface is quickly evaporated; in the medium-temperature stage (120°C), infrared radiation penetrates deep into the sand mold to remove bound water and avoid residual moisture inside that may cause cracking in the later stage; in the high-temperature stage (150°C), the binder is solidified to form a high-temperature resistant barrier.

[0043] Waste heat utilization: Integrating waste heat from the foundry (such as exhaust gas from forging furnaces) and auxiliary heating reduces energy consumption, saving more than 40% energy compared to traditional electric heating.

[0044] 4. Environmental protection and recycling principles Water-based paint replaces solvent-based paint: eliminates VOC emissions, sodium bentonite and diatomaceous earth are natural minerals, reducing chemical pollution.

[0045] Paint circulation system: The filter screen filters out impurities (such as sand particles and coagulum), and the circulation mechanism maintains the fluidity of the paint, achieving more than 90% reuse of the paint and reducing waste generation.

[0046] Example 2: Reference Figure 1 As shown: An energy-saving and environmentally friendly surface treatment method for resin sand casting based on a dip coating process, the surface treatment method is based on a surface treatment device, the surface treatment device includes a closed cabin 1, an outer shell 2 and a conveying member 3, and the surface treatment method includes the following steps: S1. Preparation of water-based environmentally friendly coating: Weighing and mixing coating raw materials to prepare water-based environmentally friendly coating; The raw materials of the water-based environmentally friendly coating include the following components by weight percentage: 60% diatomaceous earth-based aggregate, 5% sodium bentonite, 10% water-based resin binder, 25% deionized water, and 0.1% nano titanium dioxide; In step S1, the preparation of water-based environmentally friendly coating includes the following steps: S11, pre-mixing of raw materials: adding diatomaceous earth-based aggregate, sodium bentonite and deionized water into a stirring container, stirring at a speed of 300 rpm for 5 minutes to form a uniform slurry; S12, nanomaterial addition: add nano titanium dioxide to the uniform slurry, start the high-speed disperser and stir for 10 minutes at a dispersion speed of 2000 rpm to ensure that the nanoparticles are evenly dispersed and avoid agglomeration; S13, binder mixing: adjust the stirring speed to 100 rpm, add water-based resin binder, and stir for 15 minutes to form a low-viscosity water-based environmentally friendly coating; S2, intelligent dipping process: the resin sand mold is sent into the dipping frame 7 for dipping, and the coating thickness is monitored in real time for regulation; In step S2, the smart dip coating process includes the following steps: S21. Immersion Control: Clamp the resin sand mold and immerse it into the adjustable dipping frame 7 at a speed of 1 cm / s. Simultaneously, adjust the immersion angle so that the coating can cover all parts of the complex structure of the sand mold. In particular, for sand molds with special structures such as deep cavities and bosses, the coating can be applied in an inclined or vertical manner to eliminate blind spots, ensure full coverage, and avoid partial uncoated or uneven coating. S22, negative pressure adsorption: After the resin sand mold is completely immersed in the coating, the negative pressure adsorption device is turned on to maintain the pressure at -0.05MPa. The infrared thickness sensor installed above the dipping frame 7 continuously monitors the coating thickness on the sand mold surface at a frequency of collecting 10 sets of data per second. The sensor transmits real-time data quickly and accurately to the AI ​​control system through a high-speed data transmission module, providing data support for subsequent intelligent adjustment; S23. Thickness adjustment: The coating thickness data received in real time is compared and analyzed with the preset standard. If the coating thickness is insufficient, the system automatically issues instructions to extend the dipping time or increase the negative pressure adsorption pressure to increase the coating adhesion to ensure that the coating reaches the preset thickness. If the coating is too thick, the system reduces the dipping time or reduces the negative pressure to avoid paint waste and quality problems caused by excessively thick coatings.

[0047] In step S23, thickness adjustment includes the following steps: A1. Obtain the data collected by the infrared thickness sensor, process the collected data, remove abnormal values, and ensure data stability; A2. Determine the preset coating thickness standard, dynamically adjust the threshold range based on the sand mold material and casting accuracy requirements, compare the real-time thickness data with the preset threshold, and calculate the average thickness deviation Δh and regional thickness uniformity index. For example, the difference between the maximum and minimum thicknesses is ≤5% of the target thickness. A3. When three consecutive sets of data show that Δh < -5% of the target thickness, the coating thickness is judged to be insufficient and a thickening adjustment instruction is triggered. When Δh > +5% of the target thickness, the coating thickness is judged to be too thick and a thinning adjustment instruction is triggered. An adjustment strategy is generated based on the instruction, with the coating time being adjusted first. If the target is still not met, the negative pressure value is adjusted. A4. After the adjustment strategy is implemented, the sensor continues to collect data to verify whether the coating thickness has entered the target range. If the target is not met after two consecutive adjustments, the system will automatically trigger an alarm and perform abnormal processing.

[0048] S3, gradient drying: decompose and control the temperature and time, volatilize the moisture in the coating, and solidify the binder; In step S3, gradient drying includes the following steps: S31, dripping treatment: the resin sand mold after dipping is lifted from the dipping frame 7, and the excess coating on the sand mold surface is accelerated to drip by micro-vibration. The micro-vibration frequency is 20Hz to avoid sagging or excessive thickness of the coating in some areas during drying, and to prevent bubbles from remaining on the sand mold surface; S32, low-temperature removal of free water: Utilizing waste heat from the foundry, the air is heated to 80°C through a plate heat exchanger to remove free water from the coating, thus preventing rapid evaporation of water and cracking of the coating surface. Control parameters: Heating rate: 5°C / min to avoid sudden temperature rise; Ventilation volume: 100m³ / h・m² sand mold surface area, axial flow fan is used to maintain air flow in the furnace to accelerate water evaporation; Humidity monitoring: When the humidity inside the furnace is greater than 60%RH, the dehumidification valve will automatically open to discharge moisture to the outside of the workshop or condense and recover it; S33, medium temperature removal of bound water: using infrared radiation heating with a wavelength of 2μm, directional heating is performed deep in the sand mold cavity to remove bound water adsorbed between the aggregate and the binder in the coating, while preliminarily activating the cross-linking reaction of the water-based resin binder; Control parameters: Heating rate: 3°C / min to avoid premature over-curing of the adhesive; Ventilation volume: Reduce to 50m³ / h・m² to reduce the disturbance of air convection on the coating, while maintaining a slight positive pressure of 50Pa to prevent the entry of external dust; Atmosphere control: Introduce dry nitrogen with a purity of ≥99.9% to reduce the oxygen content in the furnace to below 15% to inhibit the oxidative decomposition of water-based resin; S34, high temperature curing binder: mainly using the residual heat from casting, supplemented by electric heating compensation, to completely cure the water-based resin binder to form a dense high temperature resistant coating, while enhancing the adhesion between the coating and the sand mold surface; Control parameters: constant temperature time: 10 minutes; Circulation mode: Start horizontal airflow circulation in the furnace at a speed of 0.5m / s to avoid local overheating; Safety protection: an over-temperature interlock device is set up, which automatically cuts off the heating power when the temperature is greater than 160℃ and starts the cooling fan to cool down; S35, cooling and taking out of the oven: After drying, turn off the heating source and allow to cool naturally. Open the oven door when the oven temperature drops below 60°C to prevent internal stress in the sand mold due to excessive temperature difference. Check the coating surface condition with a visual system and spot-check the coating thickness with an electromagnetic induction thickness gauge.

[0049] S4. Paint recycling: The paint in the dipping frame 7 passes through the filter 10 to remove large particles of impurities, and the filtered paint flows back to the dipping frame 7 for reuse. At the same time, the paint composition is regularly tested, and new paint is added according to the loss to maintain process stability.

[0050] Example 3: Reference Figure 2-Figure 6 As shown: An energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dipping process, the surface treatment device also includes a closed cabin 1 and an outer shell 2, a dipping frame 7 is fixedly connected to the inner side of the closed cabin 1, a clamping mechanism 8 is provided above the dipping frame 7, the clamping mechanism 8 is installed on the inner side of the closed cabin 1, and a VOC adsorption mechanism 6 is installed on the top side of the closed cabin 1. The VOC adsorption mechanism 6 absorbs the VOC components released by the paint through activated carbon + catalytic combustion; a filter screen 10 is installed on the inner side of the dipping frame 7, and a circulation mechanism 9 is installed on the outer side of the dipping frame 7. One end of the circulation mechanism 9 is connected to the bottom side of the dipping frame 7, and the circulation mechanism 9 is used to recycle the paint; a conveying member 3 is installed inside the outer shell 2, a drying mechanism 4 is fixedly connected to the top of the outer shell 2, and the two sides of the outer shell 2 are respectively connected to two switch mechanisms 5; a temperature sensor 11 is fixedly connected to one side of the outer shell 2, and the temperature sensor 11 is used to monitor the drying temperature inside the outer shell 2.

[0051] First, the resin sand mold is fixedly clamped by the clamping mechanism 8, and the resin sand mold is moved to the inside of the closed cabin 1. The entry speed and angle are controlled, and the resin sand mold is immersed in the water-based paint inside the dipping frame 7 so that the coating is evenly adhered to the surface of the resin sand mold. The VOC adsorption mechanism 6 adsorbs the VOC generated during the dipping process. After the dipping is completed, the clamping mechanism 8 sends it out from the inside of the closed cabin 1 and into the inside of the outer shell 2 through the conveying member 3. The drying mechanism 4 is connected to the plate heat exchanger to recover the forging waste heat and send it into the inside of the outer shell 2 to dry the resin sand mold. Gradient drying is used to improve the drying effect of the resin sand mold. The paint in the dipping frame 7 passes through the filter 10 to remove large particles of impurities. The filtered paint is sent back to the inside of the dipping frame 7 through the circulation mechanism 9 to achieve the reuse of the paint.

[0052] The present invention first weighs diatomaceous earth-based aggregate, sodium bentonite, water-based resin binder, deionized water and nano-titanium dioxide according to a proportion, and prepares a low-viscosity water-based environmentally friendly coating through premixing, nano-material dispersion and binder mixing; then, the resin sand mold is positioned by a clamping mechanism 8 and immersed in a dipping frame 7. After complete immersion, negative pressure adsorption is turned on, and the coating thickness is monitored in real time by an infrared thickness sensor and transmitted to a control system. The control system adjusts the dipping time and negative pressure value by comparing with a preset standard when three consecutive sets of data deviate, thereby achieving precise control of the coating thickness; after dipping, the sand mold is drained and gradient dried, and then the free water is removed at a low temperature of 80°C, the bound water is removed at a medium temperature of 120°C, and the binder is cured at a high temperature of 150°C, and the mold is naturally cooled to below 60°C and taken out of the oven for testing; during the dipping process, the paint in the tank is filtered through a filter screen 10 and then refluxed for recycling, thereby achieving repeated use of the paint. The overall process achieves the dual goals of energy saving and environmental protection and high-quality coatings through intelligent control, gradient heating and a circulation system.

[0053] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An energy-saving and environmentally friendly surface treatment method for resin sand casting based on a dip coating process, characterized in that: The surface treatment method is based on a surface treatment device, the surface treatment device comprising a dipping frame (7) and a filter screen (10), and the surface treatment method comprises the following steps: S1. Preparation of water-based environmentally friendly coating: Weighing and mixing coating raw materials to prepare water-based environmentally friendly coating; The water-based environmentally friendly coating raw materials include the following components according to weight percentage: 60% to 70% diatomaceous earth-based aggregate, 5% to 8% sodium bentonite, 10% to 15% water-based resin binder, 25% to 50% deionized water, and 0.1% to 0.3% nano titanium dioxide; S2, intelligent dipping treatment: the resin sand mold is sent into the dipping frame (7) for dipping, and the coating thickness is monitored in real time for regulation; S3, gradient drying: decompose and control the temperature and time, volatilize the moisture in the coating, and solidify the binder; S4, paint recycling: the paint in the dipping frame (7) passes through the filter (10) to remove large particles of impurities, and the filtered paint flows back to the dipping frame (7) for reuse.

2. The energy-saving and environmentally friendly surface treatment method for resin sand casting based on the dip coating process according to claim 1 is characterized in that: In step S1, the preparation of water-based environmentally friendly coating includes the following steps: S11, pre-mixing of raw materials: adding diatomaceous earth-based aggregate, sodium bentonite and deionized water into a stirring container, stirring at a speed of 300-500 rpm for 5 minutes to form a uniform slurry; S12, nanomaterial addition: add nano titanium dioxide to the uniform slurry, start the high-speed disperser and stir for 10 minutes; S13, binder mixing: add water-based resin binder and stir for 15 minutes to form a low-viscosity water-based environmentally friendly coating.

3. The energy-saving and environmentally friendly surface treatment method for resin sand casting based on the dip coating process according to claim 2, characterized in that: In step S2, the smart dip coating process includes the following steps: S21, immersion control: clamping the resin sand mold, immersing the sand mold into the dipping frame (7), and adjusting the immersion angle; S22, negative pressure adsorption: After the resin sand mold is completely immersed in the coating, the negative pressure adsorption device is turned on and the infrared thickness sensor monitors the coating thickness on the sand mold surface; S23, thickness adjustment: compare and analyze the received coating thickness data with the preset standard, issue instructions based on the coating thickness results, and adjust the coating thickness.

4. The energy-saving and environmentally friendly surface treatment method for resin sand casting based on the dip coating process according to claim 3 is characterized in that: In step S23, thickness adjustment includes the following steps: A1. Obtain the data collected by the infrared thickness sensor and process the collected data; A2. Determine the preset coating thickness standard, compare the real-time thickness data with the preset threshold, and calculate the average thickness deviation Δh and regional thickness uniformity index; A3. Determine the coating thickness based on the average thickness deviation, trigger the adjustment strategy, and adjust the coating parameters; A4. After the adjustment strategy is implemented, the sensor continues to collect data to verify whether the coating thickness falls within the target range.

5. The energy-saving and environmentally friendly surface treatment method for resin sand casting based on the dip coating process according to claim 4 is characterized in that: In step S3, gradient drying includes the following steps: S31, dripping treatment: lift the resin sand mold after dipping from the dipping frame (7), and accelerate the dripping of excess coating on the sand mold surface through micro-vibration; S32, low-temperature free water removal: using the waste heat from the foundry, the air is heated to 80°C through a plate heat exchanger to remove free water from the coating; S33, medium temperature removal of bound water: using infrared radiation heating, directional heating is carried out in the deep part of the sand mold cavity to remove the bound water adsorbed between the aggregate and the binder in the coating; S34, high temperature curing binder: mainly using the residual heat from casting, supplemented by electric heating compensation, to completely cure the water-based resin binder to form a dense high temperature resistant coating; S35, cooling and taking out of the oven: After the drying is completed, turn off the heating source and let it cool naturally. Open the oven door when the oven temperature drops below 60℃.

6. The energy-saving and environmentally friendly surface treatment method for resin sand casting based on the dip coating process according to claim 5, characterized in that: In step S35, the resin sand mold that has been cooled and taken out of the furnace is visually inspected to check the surface condition of the coating, and the coating thickness is randomly inspected using an electromagnetic induction thickness gauge.

7. An energy-saving and environmentally friendly surface treatment system for resin sand casting based on a dip coating process, characterized in that: An energy-saving and environmentally friendly surface treatment method for resin sand casting based on a dipping process as described in any one of claims 1 to 6 above is used, and the surface treatment device also includes a closed cabin (1) and an outer shell (2), a dipping frame (7) is fixedly connected to the inner side of the closed cabin (1), a clamping mechanism (8) is provided above the dipping frame (7), the clamping mechanism (8) is installed on the inner side of the closed cabin (1), and a VOC adsorption mechanism (6) is installed on the top side of the closed cabin (1), and the VOC adsorption mechanism (6) absorbs VOC components released by the coating through activated carbon + catalytic combustion.

8. The energy-saving and environmentally friendly surface treatment system for resin sand casting based on the dip coating process according to claim 7, characterized in that: A filter screen (10) is installed on the inner side of the dipping frame (7), and a circulation mechanism (9) is installed on the outer side of the dipping frame (7). One end of the circulation mechanism (9) is connected to the bottom side of the dipping frame (7), and the circulation mechanism (9) is used to recycle the paint.

9. The energy-saving and environmentally friendly surface treatment system for resin sand casting based on the dip coating process according to claim 7, characterized in that: A conveying member (3) is installed inside the outer shell (2), a drying mechanism (4) is fixedly connected to the top of the outer shell (2), and two sides of the outer shell (2) are respectively connected to two switch mechanisms (5).

10. The energy-saving and environmentally friendly surface treatment system for resin sand casting based on the dip coating process according to claim 7, characterized in that: A temperature sensor (11) is fixedly connected to one side of the outer shell (2), and the temperature sensor (11) is used to monitor the drying temperature inside the outer shell (2).

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