Chapter 5 Overview

1. Chapter 5 Overview • Casting die is the other major component • Casting die has four functions: • Hold molten metal in shape of desired casting • Provide means for molten metal to get into the space where it is held in desired shape • Remove heat from molten metal to solidify it • Provide for removal of the solidified metal

2. Chapter 5 Objectives • Identify the four types of casting dies • Identify the three major casting die modules • Identify the purpose of each major die component

3. New Terms • Cavity • The void or empty space in the die that fills with metal to make the casting • Gate • The smallest restriction in the alloy flow path, located at the edge of the casting • OEM • Acronym for Original Equipment Manufacturer • Overflows/lifters • Small pockets of alloy located around the edge of the casting

4. New Terms cont. • Runner • Die cast alloy distribution system within the casting die • Shot • All the injected material • Vacuum vent • Helps get the air out of the die cavity. • Vent • Path from the die cavity to outside the die

5. Die Ownership • The OEM owns the tooling required to make the die casting • If GM opted to purchase casting from a custom producer, the custom producer would buy casting die from a toolmaker and then sell the die to GM • If GM opted to manufacturer the casting in its own plant, GM would buy the die from a toolmaker directly

6. Types of Dies • Single cavity die • Produces one casting at a time • Multiple cavity die • Produces more than one casting at a time • Family die • Produces a number of different parts • Unit die • OEM owns the unit die and the custom die caster owns the mold base or unit die holder

7. Unit Die System • Advantages • Lower tooling costs • Shorter lead times • Potentially lower piece part costs • Disadvantages • Reduced flexibility in part design • Limited size • Possible problem moving tooling from one vendor to another without additional tooling costs

8. Mold base • Steel envelope that is designed to hold all the other die components together • Usually made from a pre-hardened steel such as a P-20 or AISI 4140

9. Stationary half mold base • Acts as container for stationary die cavities • Provides means for attaching stationary die half to machine • Couples injection system to the die • Provides a means for aligning to two die halves • Has several components

10. Stationary Half MoldBase Components • Clamp slots • Guide pins • Pryslots • Mounting/clamp plate

11. Moving half mold base • Acts as container for the die cavities • Couples ejection system to the cavities • Provides means for aligning the two die halves • Components include: • Guide bushings

12. Ejector box • Provides a means for mounting moving half mold base to moving machine platen • Supports moving half mold base against machine closing force and force of injection • Couples machine ejector system to die ejector system • Has several components

13. Ejector Box Components • Parallels/rails • Clamp plate • Support pillars

14. Ejector system • Inside the ejector box • Provides one of four critical die functions, to ‘provide for removal of the solidified metal’ • Has several components

15. Ejector System Components • Ejector pins • Return pins • Ejector plate • Ejector return plate • Guided ejection

16. Core pin Casting Die Cavity • Cavity blocks • Core pins • Slides • Carrier • Wedgelock • Cam pin • Cooling lines • Heaters

17. Die Cavity cont. • Several cavity features share same terminology as the die cast shot • Sprue • Runner • Gate • Overflows • Vents

18. Miscellaneous Components • Biscuit block • Sprue bushing • Sprue post • Stop buttons • Quick eject cam and pins

19. Summary • Casting die is the other major component • Has four functions • Castings can be manufactured by the OEM or purchased from a custom producer • 4 casting die forms: single cavity, multiple cavity, family and unit • A typical die contains 3 modules: stationary mold base, moving mold base and ejector box

20. Summary cont. • Unit dies are not complete dies; have certain advantages and disadvantages for the OEM • There are many components to casting dies • Mold base • Stationary half mold base • Moving half mold base • Ejector box • Ejector system • Die cavities