Disseny de motlles de fosa de precisió

12,858 Vistes 2024-10-26 14:29:49

A brief introduction to precision casting mold design

Precision casting mold design is one of the key links in the precision casting process.

Colada de precisió, també conegut com càsting d'inversió or lost wax casting, is a high-precision casting method that is mainly used to manufacture parts with complex shapes and precise dimensions.

The following is a brief introduction to precision casting mold design:

Overview of Precision Casting

• Definició: Precision casting is a method of using molten metal to fill a prefabricated mold and obtain a casting of the desired shape and size after cooling.
• Característiques: It can produce castings with complex shapes, thin walls and high dimensional accuracy, suitable for aerospace, automoció, camps mèdics i altres.

Basic principles of mold design

• Precision requirements: The design of the mold must ensure the dimensional accuracy and surface finish of the casting.
• Selecció de material: The mold material should have good high temperature resistance, wear resistance and corrosion resistance. Common materials include stainless steel, acer per a eines, etc.
• Structural design: The structure of the mold should be reasonable, easy to demould and maintain, and the optimization design of the pouring system should be taken into account.
• Tractament tèrmic: The mold material needs to be properly heat treated after processing to improve its hardness and service life.

Disseny de motlles de fosa de precisió

Main contents of mold design

• Cavity design: Design a suitable cavity according to the shape and size of the casting. The cavity should minimize the number of parting surfaces to avoid flash and burrs.
• Gating system design: Including the design of gates, runners and risers. The pouring system should ensure the smooth flow of molten metal and avoid the generation of pores and inclusions.
• Exhaust system design: Design reasonable exhaust holes to ensure that the gas in the cavity can be discharged smoothly to prevent pore defects.
• Cooling system design: Design cooling water channels, control the mold temperature, and improve the solidification speed and quality of castings.
• Positioning and guiding devices: Design suitable positioning pins and guiding devices to ensure accurate alignment of the upper and lower molds.

Steps of mold design

• Demand analysis: Clarify the shape, mida, material and performance requirements of the casting.
• Preliminary design: Draw the preliminary design drawing of the mold and determine the main parts such as the cavity, pouring system, and exhaust system.
• Detailed design: Refine the various components of the mold and perform precise dimensioning and tolerance design.
• Simulation analysis: Utilitzar el disseny assistit per ordinador (CAD) and simulation software (such as ProE, SolidWorks, Moldflow, etc.) to perform simulation analysis of the mold to verify the rationality of the design.
• Trial production and debugging: Make a mold prototype, conduct trial casting and debugging, and make necessary modifications based on the actual effect.
• Mass production: Complete the final design and manufacturing of the mold and put it into mass production.

Precautions for precision casting mold design

The following aspects should be paid attention to when designing precision casting molds

• 1. Geometry and structure: Precision casting usually requires high precision and complex geometry, so the mold design should take into account the shape, size and structure of the required parts to ensure that the mold can accurately replicate the required shape and size.
• 2. Selecció de material: The mold material should have high strength, alta duresa, wear resistance and heat resistance to meet the requirements of precision casting. Commonly used mold materials include tool steel, carbur cimentat, etc.
• 3. Sistema de refrigeració: Reasonably design the cooling system to ensure that the surface and internal temperature of the mold are evenly distributed to avoid thermal stress and thermal deformation, and improve the accuracy and surface quality of the casting.
• 4. Pouring system: Design a reasonable pouring system to ensure that the metal can enter the cavity smoothly and avoid defects such as gas inclusions and thermal cracks. The gate position, shape and number should be optimized according to the geometry and requirements of the casting.
• 5. Exhaust system: Design a good exhaust system to ensure that the gas in the mold cavity can be discharged smoothly to avoid defects such as pores and bubbles.
• 6. Mold structure and demolding method: Designing a reasonable mold structure and demolding method ensures that the mold can be disassembled smoothly, is easy to clean and maintain, and reduces mold damage.
• 7. Tractament superficial: Properly treat the mold surface such as surface hardening, poliment, recobriment, etc. to improve the wear resistance and service life of the mold.
• 8. Mold accessories and accessories: Consider the use and maintenance of the mold to select appropriate mold accessories and accessories, such as guide pins, cooling pipes, cargols, etc.

En resum, the design of precision casting molds needs to comprehensively consider factors such as geometry, materials, cooling system, pouring system, exhaust system, mold structure, tractament superficial, etc. to ensure that the mold can meet the requirements of precision casting and improve production efficiency and casting quality.