Chapter 4 Overview

1. 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

2. 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

3. New Term • Solenoid • An electromagnet that shifts a metal core

4. DCM’s Systems • Structural • Electrical • Hydraulic • Safety

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. Electrical: Solenoids • Shift the valves that control the volume and direction of hydraulic oil flow

12. 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

13. 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

14. 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

15. Hydraulic: Filters • Filter(s) are required to keep the hydraulic fluid clean • Located at the outlet of the pumps • Require routine maintenance

16. 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

17. 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

18. 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

19. Hydraulic:Injection Components • Inject the metal into the die • Hot chamber components include: • Shot cylinder, plunger coupling, plunger, rings, gooseneck, bushing and nozzle

20. Hydraulic:Injection Components • Cold chamber components include: • Shot cylinder, plunger rod and tip, coupling and the cold chamber

21. Hydraulic:Accumulator • A large steel tank • Partially filled with hydraulic oil • Above oil is high-pressure nitrogen gas • Used when large volume of oil required

22. 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

23. 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

24. 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

25. 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 coupled with safety-conscious actions