In the production process of hot formed products, the mold needs to be continuously water-cooled to ensure that the mechanical properties of the parts meet the requirements during continuous production. The pressure, flow rate, and flow rate of cooling water inside the mold have a direct impact on production efficiency and quality. To ensure the quality of the products produced, the water tightness of the mold must be effectively ensured, and the flow rate and flow rate in the water circulation system need to be monitored. Therefore, it is necessary to test the sealing of the mold water channel during the mold assembly process.
1. Functional requirements
The water tightness detection device can simulate the state of the cooling system during the production process, used to detect the water tightness and leakage points of the mold water circuit for filling, and to clean impurities in the mold water circuit. This device can simulate the testing process in the assembly area, with strong mobility, reducing the working hours of the press, improving the efficiency of the press, making the working location for mold water tightness testing flexible, improving the overall work progress, and shortening the assembly cycle.
According to the production process requirements, when the hot forming mold enters the production line for production, the water pressure set by the production line to enter the mold waterway is 8 MPa. Therefore, during the mold assembly process, it is necessary to ensure that there is no water leakage at slightly higher pressure in order to meet the production line requirements.
2. Structure
The water testing device and mold are independent individuals, and the rectification device consists of a water storage unit, a control and detection unit, a connection unit, and a moving unit. The water storage module includes a water tank, filter screen, and magnet. The control and detection unit includes a water pump, throttle valve, pressure gauge, and flow meter. The connection unit includes water pipes and quick connectors. The mobile unit includes a flatbed truck that carries the entire device. The schematic diagram of the device is shown in Figure 1. When using the device in the module, it is necessary to connect the inlet and outlet pipes to the mold, forming a closed circuit with the water circuit in the mold. Therefore, in the early mold design, corresponding connection ports need to be designed on the mold. In practical operation, to facilitate the disassembly and assembly of water pipes, a quick connector is designed and installed to achieve quick connection with the water testing device. The functions and specifications of structural components are shown in Table 1.
3. Principle
In the design stage of hot forming molds, in order to meet the cooling requirements in actual production of the mold, specific set values are specified for the flow rate and flow rate of the mold waterway through calculation and simulation in the process design. Only when the actual value is greater than or equal to the set value, can the production process and products of the mold meet the quality requirements of the product itself. Therefore, in order to ensure that the simulated state during testing is the same as the actual production state, during the manufacturing process of testing equipment, There are certain range requirements for the selection of water pumps, and it is necessary to select a water pump with a flow range that meets the requirements. The device experiment is shown in Figure 2.
During the waterway processing of hot forming molds, a small amount of metal debris will remain in the waterway channel, and it is also difficult to prevent dust and impurities from entering the waterway channel during the assembly process. Long term blockage of the waterway channel with small pore size and non circulation of the waterway can seriously affect the cooling effect of the mold during actual production. Therefore, before the mold enters the production line for formal production, it is necessary to clean the waterway of the mold, Ensure smooth water flow to ensure the cooling effect of the mold during actual production process.
4. Usage method
After the device is connected to the mold, the water pump passes cooling water into the mold and applies pressure. The water is sealed into the mold using a throttle valve [12] to maintain the water pressure above 8 MPa. After 10 minutes, the pressure drop is tested to confirm the sealing effect. If the pressure drop changes slightly and the overall mold has no water leakage, it proves that the sealing of the mold water path meets the production requirements of the production line; If the pressure drops significantly or there is water leakage in the mold, it indicates that the water tightness of the mold does not meet the requirements.
After the device is connected to the mold, the water pump injects water into the mold to form a cooling water system circulation. The electronic flow meter and flow meter on the equipment are used to measure the flow rate and actual value of the water flow, ensuring that the sealing of the mold waterway meets the process design requirements.
Using a water solution mixed with a certain concentration of cleaning agent to circulate in the mold waterway can effectively remove residual iron filings and impurities with oil stains from the waterway. Design a filter screen and an electromagnet device in the water tank of the device, using the filter screen to collect non-metallic impurities and large particle metal impurities, and using an electromagnet to collect small particle metal impurities. After cleaning, concentrate the collected impurities for cleaning.
During the mold assembly process, due to the unfixed storage space, it is necessary for the water testing device to have independence, easy to move and use, and small footprint. Therefore, a movable unit was added in the design, allowing the device to move flexibly, making the location of the mold waterway water tightness simulation testing process flexible and enabling flexible selection of simulation testing locations.
5. Conclusion
The water tightness detection device can simulate the state of the cooling water circuit of the hot forming mold during the production process, used to detect the water tightness and leakage points of the hot forming mold water circuit for filling, and to clean impurities in the mold water circuit. This device can ensure that the water seal of the hot forming mold before entering the production line is qualified, so that it can be smoothly debugged and produced on the production line. In the design and manufacturing process, the effective utilization of the production capacity of the trial production line press is greatly expanded, reducing the labor cost of testing the water tightness of the upper and lower press machines of the mold, making the location of the water testing process flexible, allowing for flexible selection of water testing locations, improving the work efficiency of mold water tightness testing, saving mold manufacturing costs, shortening the mold assembly cycle, and improving the overall work progress. This device has a wide range of applications and can be used for detecting the sealing of waterways during the mold manufacturing stage. It is also suitable for later maintenance of molds, checking and testing the sealing of molds, and performing maintenance.