Chapter 4 Overview
 The DCM
is very complex
• Mechanical, electrical, hydraulic and safety
systems all work together
 Each system
has many components
 Additional equipment may be used
4-1
Chapter 4 Objectives
 Using a
quality photograph, correctly identify
all structural components, electrical system
components, hydraulic pump components,
and safety devices
 Identify the purpose of all structural
components, electrical system components,
hydraulic pump components, and safety
devices
4-2
New Term
 Solenoid
• An electromagnet that shifts a metal core
4-3
DCM’s Systems
 Structural
 Electrical
 Hydraulic
 Safety
4-4
Structural Components
Structural components = framework
 DCM Base

• Support
• Shape is generally
a rectangular box
• Usually extends under
the entire DCM
• Rear portion enclosed
to form a steel tank used
as a reservoir for the
hydraulic fluid/oil
4-5
Structural:
Platens
3 large plates that carry the DCM loads
 Rest on the DCM base
 Stationary:
at front of DCM

• Holds stationary die
half on die space side

Moving: between stationary & rear platen
• Moving/ejector half of die is mounted to it

Rear: at rear of DCM
• Slides back and forth as the tie bars stretch
4-6
Structural:
Tie bars
4 tie bars are long,
round, solid beams
mounted through four
corners of platens
 Hold the DCM together
 Moving platen slides along the tie bars
 Size and strength of the tie bars determines the size
of the DCM
 Some DCM’s replaced tie bars with a solid frame
made from a casting
4-7

Structural:
Toggle mechanism
 Connects rear
and moving platens
 Acts as a lever and gains a mechanical
advantage during die close and locking
 It overcame the deficiencies of using a large
cylinder
4-8
Electrical Components
 Electrical energy powers
and controls the
DCM
 The electric power is converted to hydraulic
energy in order to do the actual work of the
DCM
4-9
Electrical:
Motor and Control Panel
Electric motor(s) located at rear of DCM are directly
coupled to the hydraulic pump
 Electrical energy is converted into hydraulic energy
 Pumps force oil into the
hydraulic lines under pressure
 Pose electric shock hazard

4-10
Electrical:
Solenoids
 Shift the valves
that control the volume and
direction of hydraulic oil flow
4-11
Electrical:
Limit Switches




Limit switches are the sensors, the eyes and ears, of
the electrical control system
Sense the position of doors, guards, cylinders and
other moving components
Maintenance is essential
to the safe operation
of the DCM
Other types of switches
and sensors, also
4-12
Hydraulic System
 DCM
is operated by a hydraulic system
• A fluid, fire-resistant oil is used to power the
cylinders that make the DCM move
• Operates at high pressures and high flow rates
 Hydraulic fluid is
hot and can cause burns
• Repair/clean leaks and spills quickly
4-13
Hydraulic:
Hydraulic pumps
DCM typically has two hydraulic pumps
 One pump capable of providing oil at high
pressures but in low volumes
 A second pump capable of providing a high volume
of oil at low pressures

4-14
Hydraulic:
Filters
 Filter(s) are
required to keep the hydraulic
fluid clean
• Located at the outlet of the pumps
 Require routine maintenance
4-15
Hydraulic:
Valves

Used to control amount and direction of oil flow
• Solenoid-operated valves direct the flow to the head or
rod side of a cylinder or direct oil to shift a large valve
May be manually operated
 Series of valves mounted on a manifold may control
the DCM’s speed control

4-16
Hydraulic:
Heat Exchanger

Operates similarly to a boiler
• Hot hydraulic oil and cooling water run through the heat
exchanger; the water cools the oil

Leakage can be troublesome
• Hydraulic oil could be contaminated by water
• Cooling water could be contaminated by the hydraulic oil
4-17
Hydraulic:
Cylinders
 Open and close the DCM
 Inject the
metal into the die
 Operate the ejection system
 Move slides on the die
 Actuate a safety ratchet and open and close a
safety door at the die parting line
4-18
Hydraulic:
Injection Components
Inject the metal
into the die
 Hot chamber
components include:

• Shot cylinder, plunger
coupling, plunger, rings,
gooseneck, bushing
and nozzle
4-19
Hydraulic:
Injection Components

Cold chamber components include:
• Shot cylinder, plunger rod and tip, coupling and the cold
chamber
4-20
Hydraulic:
Accumulator
A large steel tank
 Partially filled with
hydraulic oil
 Above oil is highpressure nitrogen gas
 Used when large
volume of oil required

4-21
Hydraulic:
Intensifier
Hydraulic device that increases hydraulic fluid
pressure at end of injection stroke
 This high pressure dramatically increases the metal
pressure to:

• Squeeze additional metal
into the die cavity as the
metal shrinks
• Further compress
trapped gases
4-22
Safety Components
 Die
casting workplace has many hazards
associated with it
 DCM operates with high pressures, high
forces, and high voltages using liquid metal
at high temperatures
 Need safety components and devices help
ensure everyone’s safety
4-23
Safety cont.
 Die
space area is protected by safety doors
or gates
• Prevent access to this area when the DCM closes
 Guards at
the toggle mechanism prevent
access to mechanism when operating
 Safety ratchet prevents the DCM closing
• DCM will only close if safety conditions have
been met and ratchet dog is withdrawn
4-24
Summary
 Structural system form
the basis of the
machine, providing support
 Electrical system provide power to the
machine and control it
 Hydraulic system use a fluid, fire-resistant oil
to power the cylinders that make DCM move
 Safety components help prevent injuries and
accidents, when used appropriately and
4-25
coupled with safety-conscious actions