How stable is the ejector pin of precision mold parts under different working temperature environments?
Publish Time: 2025-01-06
The ejector pin in precision mold parts plays the role of ejecting the molded part from the mold during the mold opening process. Its stability directly affects the service life of the mold and the quality of the molded part. Under different working temperature environments, the stability of the ejector pin will be affected by many factors, mainly including material selection, thermal expansion, lubrication and cooling systems.1. Material selectionHigh temperature environment: In high temperature environment, the material of the ejector pin needs to have high thermal stability and heat resistance. Commonly used materials include high-speed steel (HSS), cemented carbide (such as tungsten steel) and high-temperature alloys (such as Inconel). These materials can still maintain high hardness and strength at high temperatures, reducing deformation and wear.Low temperature environment: In low temperature environment, the material needs to have good toughness and impact resistance to prevent brittle fracture. Commonly used materials include low-temperature alloy steel and some stainless steels.2. Thermal expansionThermal expansion coefficient: Different materials have different thermal expansion coefficients. The difference in thermal expansion between the ejector pin and the mold material under high temperature may cause changes in the fit clearance, affecting the stability and accuracy of the ejector pin. Therefore, selecting materials with similar thermal expansion coefficients can reduce this effect.Thermal expansion compensation: When designing the mold, the size and fit clearance of the ejector pin can be appropriately adjusted by calculating the thermal expansion amount to compensate for thermal expansion under high temperature.3. LubricationHigh temperature lubrication: Under high temperature environment, conventional lubricants may fail or evaporate, resulting in increased friction between the ejector pin and the mold, affecting the motion stability and life of the ejector pin. Therefore, high temperature lubricants such as graphite, molybdenum disulfide or high temperature grease are required.Lubrication method: An automatic lubrication system can be used to regularly add lubricant to the contact surface of the ejector pin and the mold to ensure the lubrication effect.4. Cooling systemCooling channel: Under high temperature environment, the temperature of the mold and ejector pin will increase significantly, affecting their stability and life. By designing cooling channels in the mold, the temperature of the mold and ejector pin can be effectively reduced, and thermal expansion and thermal stress can be reduced.Cooling medium: Common cooling media include water, oil and air. Select the appropriate cooling medium according to the working temperature and environment to ensure the cooling effect.5. Surface treatmentSurface coating: Surface treatment of the ejector pin, such as chrome plating, nitriding or PVD coating, can improve its wear resistance and corrosion resistance and extend its service life.Surface roughness: Control the surface roughness of the ejector pin, reduce friction and wear, and improve movement stability.6. Structural designGuide structure: In the design of the ejector pin, adding a guide structure (such as a guide sleeve) can improve its movement stability and accuracy, reduce deflection and jamming.Elastic design: In the installation structure of the ejector pin, adding elastic elements (such as springs) can compensate for thermal expansion and manufacturing errors, and improve the stability and reliability of the ejector pin.7. Use and maintenanceRegular inspection: Regularly check the wear and clearance of the ejector pin, and replace the severely worn ejector pin in time to ensure the normal operation of the mold.Cleaning and maintenance: Regularly clean the mold and ejector pin to remove carbon deposits and impurities, maintain lubrication effect and movement stability.In summary, the stability of the ejector pin of precision mold parts under different working temperature environments is affected by many factors. By reasonably selecting materials, controlling thermal expansion, optimizing lubrication and cooling systems, performing surface treatment, improving structural design, and strengthening use and maintenance, the stability and service life of the ejector pin can be effectively improved to ensure the normal operation of the mold and the quality of the molded parts.
