Aluminum alloy gravity casting cold and hot glue composite supply system

Abstract

The invention discloses a hot and cold glue composite supply system for aluminum alloy gravity casting. The hot and cold glue composite supply system comprises a hot glue supply unit, a cold glue supply unit, a switching module, a gluing machine head, a temperature control system, a glue amount control system and a PLC central controller. The temperature control system performs segmented independent temperature control on the hot glue furnace, the hot glue pipe and the hot glue valve and performs constant temperature control on the cold glue barrel; the switching module realizes rapid switching of cold and hot glue (the response time is less than or equal to 0.5 s); the glue amount control system establishes a rotation-glue line width matching model to ensure the glue amount precision. Cooperative supply of cold glue and hot glue in the same system can be realized, the switching time is shortened from 30 minutes to less than 1 second, the water pump casting pressing qualification rate is improved from 78% to 98%, the equipment cost is reduced by 33%, and the technical problems that an existing single glue supply system cannot give consideration to the casting bonding efficiency and precision and the switching cost is high are solved. The adhesive is suitable for bonding requirements of complex castings such as water pump impellers and heavy truck gearbox bodies.

Description

Technical Field

[0001] This invention relates to the field of gravity casting equipment technology, specifically to a cold and hot adhesive composite glue supply system for gravity casting of aluminum alloys. Background Technology

[0002] In gravity casting, the bonding quality of the sand core directly determines the yield and precision of the casting. The adhesive supply method, temperature control accuracy, and adhesive quantity stability are the core factors affecting the bonding effect. Currently, the mainstream adhesive supply equipment in the industry is mainly divided into two categories: single hot adhesive supply systems and single cold adhesive supply systems. Both types of systems have insurmountable limitations in practical applications, failing to meet the dual requirements of "rapid fixation" and "precise smoothing" for complex castings. Specific problems are as follows: (a) Limitations of a single hot glue supply system Single hot glue supply systems rely on heating devices to melt the hot glue before application, offering the efficiency advantage of "instant application and removal." The curing time is typically 30-60 seconds, making them suitable for surface bonding of castings such as gearbox housings and forklift gearboxes in mass production. However, this type of system has two major drawbacks: First, insufficient temperature control precision. Existing equipment often uses a unified heating method, meaning the temperatures of the hot glue oven, hot glue pipe, and hot glue valve cannot be independently adjusted. This easily leads to localized overheating, causing hot glue carbonization (actual measurements show that when the temperature exceeds 200℃, the hot glue carbonization rate reaches 8%-12%), or localized underheating, causing the hot glue viscosity to increase (when the temperature is below 160℃, the hot glue viscosity rises above 5000 mPa·s, and the application speed decreases by 40%). Ultimately, this results in uneven application and fluctuating bond strength. The bonding strength is as low as 1.2MPa, which is lower than the industry standard of 1.5MPa. Secondly, the applicable scenarios are limited. After the hot glue solidifies, it has high hardness and cannot be repaired again. For the internal flow channels of castings that need to be "smoothed out", such as the impeller flow channel of water pumps and the spiral flow channel of water-cooled motors in new energy vehicles, the hot glue coating is prone to forming raised glue lines, which leads to an increase in subsequent processing and even causes pressure test leakage problems. When a water pump casting manufacturer uses a single hot glue supply system, the water pump pressure test qualification rate is only 78%, and the annual loss of castings scrapped due to leakage exceeds 500,000 yuan.

[0003] (ii) Limitations of a single cold glue supply system Single cold glue supply systems, with their advantages of smoothing the glue line after solidification using a scraper and achieving high glue line flatness, are suitable for castings requiring high surface precision, such as machine tool columns and valve bodies. However, they also have significant drawbacks: First, low production efficiency. The cold glue solidification time is as long as 2-4 hours, requiring an additional drying station, which prolongs the production cycle. Taking the 855 machine tool column as an example, a single cold glue supply system can only complete 40-50 glue applications per hour, far below the industry's efficiency requirement of 80 applications per hour. Second, poor environmental adaptability. The viscosity of cold glue is significantly affected by temperature. When the ambient temperature drops from 25℃ to 10℃, the viscosity of cold glue increases from 2000 mPa·s to 3500 mPa·s, increasing application resistance and making the glue line prone to breakage. When the temperature exceeds 40℃, cold glue is prone to premature curing, causing blockage of the glue bucket; thirdly, it has poor compatibility. If the casting has both "rapid fixing" and "precise smoothing" requirements (such as the gearbox housing of a heavy truck, the outer shell needs to be quickly fixed to prevent deformation, and the inner cavity needs to be smoothed to ensure accuracy), then a single hot glue system and a single cold glue system need to be configured separately. This not only increases the equipment purchase cost, but also requires additional workshop space (a single machine occupies an area of ​​about 2.5㎡, and two machines together occupy 5㎡). Moreover, frequent equipment switching increases the production time of each batch of castings by 30 minutes, resulting in a significant decrease in production efficiency.

[0004] (III) Common problems in existing technologies In addition to the individual defects of the two types of systems mentioned above, existing glue supply systems also suffer from the common problem of low glue quantity control accuracy: the matching between the glue supply gear pump speed and the glue line width is poor. When the speed fluctuates by ±10 rpm, the glue line width can fluctuate by ±0.8 mm, which can easily lead to problems such as excessive glue quantity causing foam corrosion (when cold glue is excessive, the foam corrosion rate reaches 5%-7%) or insufficient glue quantity causing insufficient bonding strength. At the same time, existing systems lack parameter adaptation functions for different castings. Every time the casting type is changed, parameters such as temperature and speed need to be manually readjusted, which takes 1-2 hours, further reducing production efficiency.

[0005] In summary, existing single adhesive supply systems cannot simultaneously achieve efficiency, precision, and compatibility. There is an urgent need for a composite adhesive supply system that can achieve coordinated supply of hot and cold adhesives, precise temperature control, and efficient switching, in order to solve the bonding pain points of complex castings and promote the technological upgrading of the sand core casting industry. Summary of the Invention

[0006] This application proposes a composite hot and cold adhesive supply system for gravity casting of aluminum alloys. It aims to solve the technical problems in existing gravity casting adhesive supply systems, such as the inability of single hot adhesive supply to meet the smoothing requirements of the internal flow channels of the casting, the low efficiency of single cold adhesive supply, and the high switching cost and poor compatibility of hot and cold adhesive supply systems. The system achieves precise temperature control, efficient switching and coordinated supply of hot and cold adhesives within the same system, taking into account both casting bonding efficiency and accuracy, and reducing equipment costs and energy consumption.

[0007] To achieve the above objectives, this application adopts the following technical solution: a composite hot and cold glue supply system for gravity casting of aluminum alloy, comprising: a hot glue supply unit, a cold glue supply unit, a switching module, a glue applicator head, a temperature control system, a glue quantity control system, and a PLC central controller; the hot glue supply unit includes a hot glue oven, a hot glue pipe, and a hot glue valve; the cold glue supply unit includes a cold glue tank and a cold glue pipe; the switching module is used to switch between the hot glue path and the cold glue path; the temperature control system is electrically connected to the hot glue supply unit and the cold glue supply unit respectively, and is used to control the temperature of the hot glue and the cold glue; the glue quantity control system is electrically connected to the glue supply gear pumps of the hot glue supply unit and the cold glue supply unit, and is used to adjust the glue supply quantity; the PLC central controller is electrically connected to the switching module, the temperature control system, the glue quantity control system, and the glue applicator head respectively, and is used to coordinate and control the operation of the entire system.

[0008] Furthermore, the temperature control system provides segmented and independent temperature control for the hot glue oven, hot glue hose, and hot glue valve. The temperature control range for the hot glue oven is 170-180℃, for the hot glue hose it is 170-175℃, and for the hot glue valve it is 168-172℃, with a temperature control accuracy of ±1℃ for each segment. The temperature control system also includes a temperature sensor and a cooling fan. The temperature sensor collects the temperature data of the hot glue oven, hot glue hose, and hot glue valve in real time. When the temperature of the hot glue oven exceeds 180℃, the PLC central controller controls the cooling fan to start, with a heat dissipation rate of 5℃ / min.

[0009] Furthermore, the temperature control system controls the temperature of the cold glue through a thermostatic jacket wrapped around the cold glue bucket. The temperature control range of the cold glue is 25-30℃, and the control accuracy is ±1℃. The cold glue bucket is also equipped with a viscosity sensor to monitor the viscosity of the cold glue in real time. When the viscosity exceeds 2500mPa·s, the PLC central controller adjusts the temperature of the cold glue through the thermostatic jacket to maintain the viscosity at 2000-2500mPa·s.

[0010] Furthermore, the switching module is a three-way solenoid directional valve or an integrated glue applicator valve; when the switching module is a three-way solenoid directional valve, its response time is ≤0.5s; when the switching module is an integrated glue applicator valve, its response time is ≤0.3s, and it has built-in heating elements and heat sinks, with the heating element having a temperature compensation rate of 2℃ / s and the heat sink having a heat dissipation rate of 1℃ / s.

[0011] Furthermore, the glue quantity control system establishes a matching model of "glue supply gear pump speed - glue line width". The glue applicator head has a built-in glue line detection sensor with an accuracy of ±0.1mm. The glue line width data is collected in real time and fed back to the PLC central controller. When the glue supply gear pump speed fluctuates by ±5 rpm, the PLC central controller adjusts the speed through the glue quantity control system to make the glue line width fluctuation ≤ ±0.1mm.

[0012] Furthermore, the hot glue supply unit and the cold glue supply unit are arranged in parallel. The volume of both the hot glue oven and the cold glue tank is 5L. The length of both the hot glue pipe and the cold glue pipe is 1.5m and the diameter is 8mm. The glue application speed of the glue applicator head is adjustable from 1 to 300mm / s.

[0013] Furthermore, the hot glue supply unit and the cold glue supply unit are integrated into the same integrated glue tank. The integrated glue tank is internally divided into a hot glue chamber and a cold glue chamber, both with a volume of 2.5L. A heat insulation layer is provided between the two chambers, and the thermal conductivity of the heat insulation layer is ≤0.03W / (m・K).

[0014] Furthermore, it also includes a shared glue supply pipe, which has a built-in hot glue passage and a cold glue passage. Both passages have a diameter of 6mm and are separated by a heat insulation partition with a thickness of ≥5mm. The hot glue passage is wrapped with a heat tracing cable, and the cold glue passage is wrapped with an insulation layer. Both the heat tracing cable and the insulation layer are electrically connected to the temperature control system.

[0015] Furthermore, the PLC central controller has a built-in casting parameter database, which pre-stores the glue supply parameters for at least 10 types of castings (engine cylinder block, forklift gearbox, tractor body, single-cylinder engine block, heavy truck gearbox, air compressor body, four major series of reducer housings, new energy vehicle water-cooled motor, construction machinery housing, and water pump). After inputting the casting type, the system automatically calls up the corresponding hot glue temperature, cold glue temperature, glue supply gear pump speed, and glue application speed parameters.

[0016] Furthermore, the glue applicator head is also equipped with a position sensor, which is electrically connected to the PLC central controller to locate the glue application position. When applying hot glue, the position sensor locates the casting shell area, and the initial fixation is completed 30-40 seconds after the glue is applied. When applying cold glue, the position sensor locates the internal flow channel area of ​​the casting, and the glue is smoothed by a scraper after application, and the curing is completed in 1.5-2 hours.

[0017] The present invention has the following beneficial effects: 1. This application provides an aluminum alloy gravity casting hot and cold adhesive composite supply system. Through a hot and cold adhesive rapid switching module, the switching time is shortened from 30 minutes in existing equipment to within 0.3-0.5 seconds, reducing the production time of each batch of castings by 25-30 minutes and increasing production efficiency by 30%-40%. Taking the four series of reducer housings as an example, the adhesive application efficiency is increased from the current 60 pieces / hour to 85 pieces / hour, meeting the industry requirement of "adhesive application efficiency > 80 pieces / hour" in the document. At the same time, the parameter database settings shorten the casting changeover and debugging time from 1-2 hours to within 10 seconds, further improving continuous production capacity.

[0018] 2. This application provides an aluminum alloy gravity casting hot and cold adhesive composite supply system. The hot adhesive is segmented and temperature controlled to reduce the carbonization rate from 8%-12% to below 1%, and the cold adhesive is constant temperature controlled to reduce the foam corrosion rate from 5%-7% to below 0.5%. The "speed-width" closed-loop control ensures that the adhesive line width fluctuation is ≤±0.1mm, and the bonding strength is stable at 1.8-2.0MPa (higher than the industry standard of 1.5MPa). The pressure test pass rate of water pump castings is increased from 78% to 98%, and the adhesive line flatness of heavy truck gearbox housing is ≤0.09mm, which fully meets the bonding requirements of high-precision castings.

[0019] 3. This application provides an aluminum alloy gravity casting hot and cold adhesive composite supply system. The integrated system transforms two single systems into one composite system, reducing costs by 33%; the floor space is reduced from 5㎡ to 1.2㎡, saving 76% of workshop space; at the same time, precise temperature control and adhesive quantity control reduce the amount of hot and cold adhesive used by 10%-15% respectively (the coating length of 1Kg cold adhesive increases from 500m to 550-575m, and the coating length of 1Kg hot adhesive increases from 700m to 770-805m), saving 20,000-30,000 yuan in annual consumable costs; in addition, the system adopts segmented heating and constant temperature control, maintaining the total power at 4.5kw (consistent with the existing single system), without any additional energy consumption increase.

[0020] 4. This application provides an aluminum alloy gravity casting hot and cold adhesive composite glue supply system. The system has a built-in database of 10 casting parameters and can be adapted to various complex castings such as engine blocks, water pump impellers, and heavy truck gearbox housings. At the same time, the temperature control range (hot glue 170-180℃, cold glue 25-30℃) and speed adjustment range (0-500 rpm) can cover mainstream hot and cold adhesive models in the industry (such as hot glue HC-265, HC-108B, cold glue AA702 / 6 BL). It can adapt to different types of adhesives without changing the glue supply unit, and its compatibility is significantly better than existing systems. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, illustrate embodiments disclosed in this application and, together with the specification, serve to explain the principles disclosed in this application.

[0022] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 This is a control flow diagram of the hot and cold adhesive composite adhesive supply system of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] To address the aforementioned technical problems, this invention provides two technical solutions for a composite hot and cold adhesive supply system for gravity casting of aluminum alloys. Both are based on the existing adhesive supply system's basic structure of "adhesive supply gear pump + adhesive applicator head," and add a segmented temperature control module, a hot and cold adhesive switching module, and an intelligent adhesive quantity matching module to achieve coordinated supply of hot and cold adhesive. (See attached diagram.) Figure 1 The details are as follows: Example 1 This embodiment applies an aluminum alloy gravity casting hot and cold glue composite glue supply system, which includes a hot glue supply unit and a cold glue supply unit arranged in parallel, a three-way solenoid reversing valve (switching module), a glue applicator head, a temperature control system, a glue quantity control system, and a PLC central controller.

[0025] The hot glue supply unit includes a 5L hot glue oven, a 1.5m long hot glue pipe (8mm diameter), and an 8mm diameter hot glue valve. The cold glue supply unit includes a 5L cold glue tank and a 1.5m long cold glue hose (8mm in diameter). The input end of the three-way solenoid directional valve is connected to the hot glue hose and the cold glue hose respectively, and the output end is connected to the glue applicator head. The glue applicator head has a built-in glue line detection sensor and position sensor with an accuracy of ±0.1mm; The temperature control system includes 3 sets of temperature sensors (installed in the hot glue oven, hot glue hose, and hot glue valve respectively), 1 set of viscosity sensors (installed in the cold glue tank), a cooling fan (installed on the outside of the hot glue oven), and a constant temperature jacket (wrapped around the outside of the cold glue tank). The glue supply control system includes a speed sensor (installed on the glue supply gear pump) and a speed regulator; the PLC central controller has a built-in casting parameter database, which pre-stores glue supply parameters for 10 types of castings such as engine blocks and water pump impellers.

[0026] The usage method is as follows: Step 1, Casting Parameter Retrieval: The operator inputs the casting type (e.g., "pump impeller") through the touchscreen of the PLC central controller. The system automatically retrieves preset parameters from the parameter database (hot glue oven temperature 175℃, hot glue pipe temperature 172℃, hot glue valve temperature 170℃, cold glue temperature 28℃, hot glue supply gear pump speed 30 rpm, cold glue supply gear pump speed 25 rpm, glue application speed 50 mm / s). If new castings need to be adapted, the parameters can be manually entered and saved to the database. This step solves the problem of time-consuming manual debugging in the existing system, reducing the parameter retrieval time from 1-2 hours to within 10 seconds.

[0027] Step 2: Segmented Temperature Control of Hot Glue: After the temperature control system is activated, three sets of temperature sensors collect temperature data from the hot glue oven, hot glue hose, and hot glue valve, respectively, and feed them back to the PLC central controller. If the temperature of the hot glue oven is below 175℃, the PLC controls the built-in heating element of the hot glue oven to raise the temperature (heating rate 3℃ / min); if the temperature of the hot glue oven exceeds 180℃, the PLC controls the cooling fan to start (cooling rate 5℃ / min); the hot glue hose is heated to 172℃ via a heating cable, and the hot glue valve is heated to 170℃ via a built-in heating element. The temperature fluctuation of each segment is controlled within ±1℃. This step solves the problem of uneven temperature caused by overall heating in existing hot glue systems, stabilizing the hot glue viscosity at 2000-2500 mPa·s (actual fluctuation range ≤100 mPa·s), avoiding hot glue carbonization (carbonization rate reduced to below 1%), and ensuring glue flowability and bonding strength.

[0028] Step 3: Cold Glue Temperature Control: The temperature control system stabilizes the cold glue temperature at 28℃ using a constant-temperature jacket outside the cold glue container. A viscosity sensor monitors the cold glue viscosity in real time: if the viscosity exceeds 2500 mPa·s, the PLC controls the constant-temperature jacket to heat up (heating rate 1℃ / min) until the viscosity drops to 2000-2500 mPa·s; if the viscosity is below 2000 mPa·s, the PLC controls the constant-temperature jacket to cool down (cooling rate 1℃ / min), preventing the cold glue from becoming too thin and causing leakage during application. This step solves the problem of existing cold glue systems being greatly affected by ambient temperature, ensuring uniform cold glue coating and reducing the foam corrosion rate from 5%-7% to below 0.5%.

[0029] Step 4, Rapid Switching Between Hot and Cold Adhesive: The position sensor of the glue applicator head locates the casting area. When hot adhesive needs to be applied (such as the water pump impeller housing), the PLC sends a signal to the three-way solenoid valve, opening the hot adhesive path and cutting off the cold adhesive path within 0.5 seconds. The glue supply gear pump delivers hot adhesive at 30 rpm, and the glue applicator head applies the adhesive at a speed of 50 mm / s, completing the housing fixation within 30 seconds. When cold adhesive needs to be applied (such as the internal flow channel of the water pump impeller), the PLC controls the three-way solenoid valve to switch to the cold adhesive path within 0.5 seconds. The glue supply gear pump delivers cold adhesive at 25 rpm, and the adhesive is smoothed by a scraper after application. During the switching process, the glue line detection sensor collects the glue line width in real time. If the width deviation exceeds ±0.2mm (such as the width decreasing from 2.8mm to 2.6mm after switching from cold to hot adhesive), the PLC adjusts the speed of the glue supply gear pump through the glue quantity control system (increasing the speed from 25 rpm to 27 rpm) to restore the glue line width to 2.8±0.1mm. This step enables efficient switching between hot and cold adhesives, reducing the switching time from 30 minutes to within 0.5 seconds, thus solving the problem of high switching costs in existing systems.

[0030] Step 5, Adhesive Application Quality Monitoring: During the adhesive application process, the adhesive line detection sensor collects adhesive line width data every 100ms, and the speed sensor collects adhesive supply gear pump speed data every 50ms, forming a "speed-width" closed-loop control. Simultaneously, the temperature sensor collects hot and cold adhesive temperature data every 200ms to ensure temperature stability. If the temperature exceeds the tolerance (e.g., the hot adhesive tube temperature drops below 168℃) or the adhesive line width exceeds the tolerance (e.g., exceeding ±0.1mm), the system automatically alarms and pauses adhesive application, restarting only after the parameters return to normal. This step ensures stable adhesive application quality, increasing the water pump impeller pressure test pass rate from 78% to 98%.

[0031] This embodiment provides an aluminum alloy gravity casting hot and cold adhesive composite glue supply system for bonding water pump impellers. The casting parameters are: water pump impeller diameter 300mm, inner flow channel width 15mm, material is expandable polystyrene (EPS), the outer shell is required to be initially fixed within 30 seconds, the flatness of the glue line in the inner flow channel is ≤0.1mm, and there is no leakage during the pressure test (0.8MPa, 30 minutes).

[0032] The aluminum alloy gravity casting hot and cold adhesive composite glue supply system of this embodiment is configured as follows: hot adhesive type HC-108B (hot adhesive granules for sand cores), cold adhesive type AA702 / 6 BL (water-based cold adhesive for sand cores); hot adhesive parameters: hot adhesive oven 175℃, hot adhesive pipe 172℃, hot adhesive valve 170℃, glue supply gear pump speed 30 rpm, glue line width 3.0 mm; cold adhesive parameters: temperature 28℃, viscosity 2200 mPa・s, glue supply gear pump speed 25 rpm, glue line width 2.8 mm; glue application speed 50 mm / s.

[0033] Implementation process: Step 1: The operator inputs "water pump impeller" on the PLC touch screen. The system will call the preset parameters within 10 seconds, and the hot glue heating tube and cold glue constant temperature sleeve will start.

[0034] Step 2: The temperature of the hot glue oven is raised to 175℃, the hot glue hose is raised to 172℃ through the heating cable, the hot glue valve is heated to 170℃, the temperature sensor provides real-time feedback data, and the temperature fluctuation is ±0.8℃; the cold glue constant temperature jacket stabilizes the cold glue temperature at 28℃, and the viscosity sensor displays a viscosity of 2200mPa・s, which meets the requirements.

[0035] Step 3: The glue applicator head moves to the water pump impeller housing area. After the position sensor positions it, the PLC controls the three-way solenoid reversing valve to open the hot glue passage within 0.5 seconds. The glue supply gear pump delivers hot glue at 30 rpm, and the glue applicator head applies the glue at a speed of 50 mm / s. After 30 seconds, the glue application on the housing is completed, the hot glue initially solidifies, and the impeller housing is fixed without deformation.

[0036] Step 4: The position sensor switches to the inner flow channel area, and the PLC controls the three-way solenoid valve to switch to the cold glue channel within 0.5 seconds. The glue supply gear pump delivers cold glue at 25 rpm, and the glue applicator head applies the glue along the inner flow channel trajectory. The glue line detection sensor collects the width data and feeds it back to the PLC in real time. When the width of a certain glue line is detected to drop to 2.6 mm, the PLC controls the speed to increase to 27 rpm, and the width is restored to 2.8 mm. After the glue application is completed, the cold glue is smoothed by hand with a scraper.

[0037] Step 5: After the cold glue has cured for 1.5 hours, perform a pressure test on the water pump impeller (0.8MPa, 30 minutes) and check the flatness of the glue line at the same time.

[0038] Experimental data and results: Efficiency indicators: The glue application time for a single water pump impeller is 4 minutes (including changeover time), and 15 units can be completed per hour, which is 87.5% higher than the existing single system (8 units per hour); the batch production time (100 units) is 340 minutes, which is 160 minutes less than the existing system (500 minutes).

[0039] Quality indicators: Hot glue carbonization rate was 0.6% (sampled and tested, percentage of carbonized portion); cold glue foam corrosion rate was 0.3% (no corrosion marks observed on the impeller surface); glue line flatness test: inner flow channel glue line flatness was 0.08mm, outer shell glue line width fluctuation was ±0.09mm; pressure test: only 1 out of 100 water pump impellers leaked, with a pass rate of 99%, far exceeding the 78% pass rate of the existing system.

[0040] Cost metrics: 100 water pump impellers consume 2.1 kg of hot glue (coating length 1470 m) and 2.8 kg of cold glue (coating length 1540 m), which is 12.5% ​​less glue than the existing system (2.4 kg of hot glue and 3.2 kg of cold glue), resulting in a saving of 86 yuan in consumable costs per batch.

[0041] Example 2 This embodiment applies an aluminum alloy gravity casting hot and cold adhesive composite glue supply system, which includes an integrated glue tank, a common glue supply pipe, an integrated glue applicator valve (switching module), a glue applicator head, a temperature control system, a glue quantity control system, and a PLC central controller.

[0042] The integrated glue tank has a volume of 5L and is internally divided into a 2.5L hot glue chamber and a 2.5L cold glue chamber. A heat insulation layer with a thermal conductivity of ≤0.03W / (m・K) is installed between the two chambers. The common glue supply pipe is 1.5m long, with built-in hot glue passage and cold glue passage (both with a pipe diameter of 6mm). A 5mm thick heat insulation partition is installed between the two passages. The hot glue passage is wrapped with a heat tracing cable, and the cold glue passage is wrapped with a heat insulation layer. The integrated glue-applying valve has a built-in heating element (heat compensation rate 2℃ / s), a heat sink (heat dissipation rate 1℃ / s), and a valve core, with a response time ≤0.3s; The structure of the glue applicator head, temperature control system, and glue quantity control system is the same as in Scheme 1.

[0043] The usage method is as follows: Step 1, Parameter Preset and Integrated Temperature Control: Input the casting type (e.g., "heavy truck gearbox housing"), and the system will call the preset parameters (hot glue chamber temperature 172℃, cold glue chamber temperature 27℃, hot glue pump speed 28 rpm, cold glue pump speed 22 rpm, glue application speed 80mm / s). The temperature control system raises the temperature to 172℃ through the built-in heating tube in the hot glue chamber and stabilizes the temperature at 27℃ through the constant temperature jacket in the cold glue chamber. The insulation layer ensures that the temperature difference between the two chambers is stable at 145±2℃ (the actual measured temperature influence of the hot glue chamber on the cold glue chamber is ≤0.5℃), avoiding cross-temperature between hot and cold glue. This step simplifies the system structure, integrating the existing two independent glue tanks into one, reducing the floor space from 2.5㎡ to 1.2㎡.

[0044] Step 2, Temperature Maintenance of the Shared Adhesive Supply Pipe: The temperature control system maintains the temperature of the hot adhesive path in the shared adhesive supply pipe at 170℃ via a heating cable, and the temperature of the cold adhesive path at 27℃ via an insulation layer. Insulation baffles prevent temperature crosstalk (actually measured, the temperature difference between the hot and cold adhesive paths is ≤0.3℃). Simultaneously, temperature detection points are installed on the outer wall of the shared adhesive supply pipe, collecting temperature data every 300ms to ensure stable path temperature. This step reduces the number of pipes, simplifying the existing four pipes (two for hot adhesive and two for cold adhesive) to two shared pipes, reducing installation complexity and maintenance costs.

[0045] Step 3: Integrated Glue Dispensing Valve Switching and Temperature Compensation: The position sensor locates the outer shell and inner cavity of the heavy-duty truck gearbox housing. When applying glue to the outer shell, the PLC controls the integrated glue dispensing valve core to open the hot glue path within 0.3 seconds, and the heating element provides real-time temperature compensation (if the hot glue temperature is below 170℃, the heating element compensates at a rate of 2℃ / s). When applying glue to the inner cavity, the valve core switches to the cold glue path within 0.3 seconds. If the cold glue temperature is above 30℃, the heat sink dissipates heat at a rate of 1℃ / s. This step further shortens the switching time and ensures temperature stability during glue type switching. The outer shell fixing time is reduced from 40 seconds to 35 seconds, and the inner cavity glue line flatness is ≤0.09mm.

[0046] Step 4: Glue application and glue quantity compensation (same as Step 5 in Solution 1): The glue line detection sensor and the speed sensor form a closed-loop control. When the speed of the glue supply gear pump fluctuates by ±5 rpm, the system automatically compensates for the speed, so that the glue line width fluctuation is ≤ ±0.1mm. After the glue application is completed, the system automatically records the glue application parameters (temperature, speed, width) to form a production log for easy follow-up.

[0047] This embodiment provides an aluminum alloy gravity casting hot and cold adhesive composite supply system for bonding water pump impellers. The casting parameters are as follows: heavy truck gearbox housing length 800mm, width 500mm, height 300mm, outer shell thickness 8mm, inner cavity with 3 flow channels (width 20mm), outer shell is required to be fixed within 40 seconds, inner cavity adhesive line flatness ≤0.1mm, and bonding strength ≥1.5MPa.

[0048] The system configuration is as follows: hot glue model HC-265 (hot glue stick), cold glue model AA702 / 6 BL; integrated glue tank hot glue chamber temperature 172℃, cold glue chamber temperature 27℃; shared glue supply pipe hot glue path 170℃, cold glue path 27℃; integrated glue dispensing valve response time 0.3s; hot glue pump speed 28 rpm (glue line width 2.9mm), cold glue pump speed 22 rpm (glue line width 2.6mm); glue dispensing speed 80mm / s.

[0049] The implementation process is as follows: Step 1: Input "heavy truck gearbox housing", the system calls parameters, the integrated glue barrel hot glue chamber heating pipe and cold glue chamber constant temperature jacket start, the shared glue supply pipe heating tape and insulation layer start.

[0050] Step 2: The temperature of the hot glue chamber rises to 172℃, while the temperature of the cold glue chamber stabilizes at 27℃. The insulation layer maintains a temperature difference of 145℃ between the two chambers, and the temperature of the hot glue chamber affects the temperature of the cold glue chamber by 0.3℃. The temperature of the hot glue passage of the shared glue supply pipe rises to 170℃, while the temperature of the cold glue passage is maintained at 27℃, which meets the requirements.

[0051] Step 3: The glue applicator head positions the outer shell area, and the integrated glue applicator valve opens the hot glue passage within 0.3 seconds. The glue supply pump delivers hot glue at 28 rpm, with a glue application speed of 80 mm / s. The glue application on the outer shell is completed in 35 seconds, and the hot glue solidifies and sets. During the glue application process, the integrated glue applicator valve has a built-in heating element that replenishes the temperature in real time. When the temperature of the hot glue drops to 169℃, the heating element replenishes the temperature to 170℃ at a rate of 2℃ / s.

[0052] Step 4: Positioning switch to the inner cavity flow channel, the integrated glue valve switches to the cold glue channel within 0.3 seconds, the glue pump delivers cold glue at 22 rpm, and the glue line detection sensor monitors the width in real time; when the speed fluctuates to 18 rpm, the width drops to 2.4mm, the PLC controls the speed to increase to 24 rpm, and the width recovers to 2.6mm; after the glue is applied, smooth out the cold glue.

[0053] Step 5: After the cold glue has cured for 2 hours, check the deformation of the outer shell, the flatness of the glue line in the inner cavity, and the bonding strength.

[0054] Experimental data and results: Efficiency indicators: The glue application time for a single gearbox housing is 6 minutes, and 10 units can be completed per hour, which is 66.7% faster than the existing single system (6 units per hour); the equipment occupies 1.2㎡, which is 76% less than the existing two-unit system (5㎡).

[0055] Quality indicators: Outer shell deformation 0.07mm (meets ≤0.1mm requirement), inner cavity adhesive line flatness 0.09mm; bonding strength test was conducted using a tensile testing machine, and the test result was 1.9MPa (higher than the 1.5MPa standard); no hot adhesive carbonization or cold adhesive corrosion.

[0056] Cost indicators: 100 cabinets consume 3.5 kg of hot glue (coating length 2450 m) and 4.2 kg of cold glue (coating length 2310 m), reducing the amount of glue by 14%, resulting in an annual material cost saving of 31,000 yuan (based on a production volume of 10,000 units).

Claims

1. A composite adhesive supply system for cold and hot adhesives in gravity casting of aluminum alloy, characterized in that, include: The system comprises a hot glue supply unit, a cold glue supply unit, a switching module, a glue applicator head, a temperature control system, a glue quantity control system, and a PLC central controller. The hot glue supply unit includes a hot glue oven, a hot glue pipe, and a hot glue valve. The cold glue supply unit includes a cold glue tank and a cold glue pipe. The switching module switches between the hot glue path and the cold glue path. The temperature control system is electrically connected to both the hot glue supply unit and the cold glue supply unit to control the temperature of the hot and cold glue. The glue quantity control system is electrically connected to the glue supply gear pumps of both the hot and cold glue supply units to adjust the glue supply quantity. The PLC central controller is electrically connected to the switching module, the temperature control system, the glue quantity control system, and the glue applicator head to comprehensively control the operation of the entire system.

2. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The temperature control system provides segmented and independent temperature control for the hot glue oven, hot glue hose, and hot glue valve. The temperature control range for the hot glue oven is 170-180℃, for the hot glue hose it is 170-175℃, and for the hot glue valve it is 168-172℃, with a temperature control accuracy of ±1℃ for each segment. The temperature control system also includes a temperature sensor and a cooling fan. The temperature sensor collects the temperature data of the hot glue oven, hot glue hose, and hot glue valve in real time. When the temperature of the hot glue oven exceeds 180℃, the PLC central controller controls the cooling fan to start, with a heat dissipation rate of 5℃ / min.

3. The aluminum alloy gravity casting cold and hot adhesive composite supply system according to claim 1, characterized in that, The temperature control system controls the temperature of the cold glue through a thermostatic jacket wrapped around the cold glue bucket. The temperature control range of the cold glue is 25-30℃, and the control accuracy is ±1℃. The cold glue bucket is also equipped with a viscosity sensor to monitor the viscosity of the cold glue in real time. When the viscosity exceeds 2500mPa·s, the PLC central controller adjusts the temperature of the cold glue through the thermostatic jacket to maintain the viscosity at 2000-2500mPa·s.

4. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The switching module is a three-way solenoid directional valve or an integrated glue applicator valve; when the switching module is a three-way solenoid directional valve, its response time is ≤0.5s; when the switching module is an integrated glue applicator valve, its response time is ≤0.3s, and it has built-in heating elements and heat sinks, with the heating element having a heating rate of 2℃ / s and the heat sink having a heat dissipation rate of 1℃ / s.

5. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The glue quantity control system establishes a matching model of "glue supply gear pump speed - glue line width". The glue applicator head has a built-in glue line detection sensor with an accuracy of ±0.1mm. The glue line width data is collected in real time and fed back to the PLC central controller. When the glue supply gear pump speed fluctuates by ±5 rpm, the PLC central controller adjusts the speed through the glue quantity control system to make the glue line width fluctuation ≤ ±0.1mm.

6. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The hot glue supply unit and the cold glue supply unit are arranged in parallel. The volume of the hot glue oven and the cold glue tank is 5L. The length of the hot glue pipe and the cold glue pipe is 1.5m and the diameter is 8mm. The glue application speed of the glue applicator head is adjustable from 1 to 300mm / s.

7. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The hot glue supply unit and the cold glue supply unit are integrated into the same integrated glue tank. The integrated glue tank is divided into a hot glue chamber and a cold glue chamber. The volume of the hot glue chamber and the cold glue chamber is 2.5L. A heat insulation layer is provided between the two chambers. The thermal conductivity of the heat insulation layer is ≤0.03W / (m・K).

8. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, It also includes a shared glue supply pipe, which has a built-in hot glue passage and a cold glue passage. Both passages have a diameter of 6mm and are separated by a heat insulation partition with a thickness of ≥5mm. The hot glue passage is wrapped with a heat tracing cable, and the cold glue passage is wrapped with an insulation layer. Both the heat tracing cable and the insulation layer are electrically connected to the temperature control system.

9. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The PLC central controller has a built-in casting parameter database, which pre-stores the glue supply parameters for at least 10 types of castings (engine cylinder block, forklift gearbox, tractor body, single-cylinder engine block, heavy truck gearbox, air compressor body, four major series of reducer housings, new energy vehicle water-cooled motor, construction machinery housing, and water pump). After inputting the casting type, the system automatically calls up the corresponding hot glue temperature, cold glue temperature, glue supply gear pump speed, and glue application speed parameters.

10. The aluminum alloy gravity casting hot and cold adhesive composite supply system according to claim 1, characterized in that, The glue applicator head is also equipped with a position sensor, which is electrically connected to the PLC central controller to locate the glue application position. When applying hot glue, the position sensor locates the casting shell area, and the initial fixation is completed 30-40 seconds after the glue is applied. When applying cold glue, the position sensor locates the internal flow channel area of ​​the casting, and the glue is smoothed by a scraper after application, and the curing is completed in 1.5-2 hours.

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