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
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