Troubleshooting Injection Plastic Presses

TROUBLESHOOTING

 PLASTIC INJECTION MACHINES

ELECTRIC AND HYDRAULICS CONTROLS

TOM KISSELL  

APPLIED TECHNETRONICS,Ltd.

 

1.   Troubleshooting Basics

  1. What Is Troubleshooting
  2. Determining Tests To Eliminate Possibilities
  3. Splitting The System (Electrical / Hydraulics / Mechanical)

 

2.  Over View Of Prints Machine Overview 

(The Basic Injection Molding Machine) and Typical Problems.

  1. Machine Cycle
  2. Extrusion (screw rotation) (Shot size controls)
  3. Clamp Motion
  4. Injection
  5. Ejection
  6. Temperature controls

 

3.  Intro To Electrical Controls and PLCs

  1. Processor
  2. Input
  3. Output
  4. Scan Cycle
  5. Relays and Contactors
  6. Motors

 

                 

4  Hydraulics Parts

  1. Pumps  (variable and fixed output)
  2. Pressure Control
  3. Flow Control (speed controls)
  4. Actuators
  5. Directional Controls                                                                    

 

 

5.  Troubleshooting Cylinders

  1. Types Of Cylinders
  2.  (Physics Of Cylinders) (Pan Cake)
  3. Double Acting
  4. Double Ended
  5. Troubleshooting Cylinders

 

6.    Troubleshooting Hydraulic Motors, Advanced Pumps and Pump Adder Circuits

  1. Screw Motor control
  2. back pressure
  3. Types Of Pumps
  4. Variable Pumps
  5. Troubleshooting Pumps And Motors

 

7.    Troubleshooting Pressure Control and Flow Control Circuits

  1. Pressure Relief Valves
  2. Pressure Reducing Valves
  3. Sequence Valves
  4. Counterbalance Valves
  5. Flow Control In And Out
  6. Throttle Valves And Check Valves
  7. Troubleshooting Valves

                                                                                                          

8.    Troubleshooting Directional Control, Pilot Operated Valves, Cartridge Valves

  1. Two And Three Position Valves.
  2. Two Way, Three Way And Four Way Valves.
  3. Pilot Operated Valves.
  4. Cartridge Valves
  5. Troubleshooting Hydraulic Circuits Using Pressure Gages, Flow Meters

 

9.  Troubleshooting and Setup of Electronic (PLC) Control of Press Hydraulics

  1. Color Screen interface to electronic controls
  2. Set up Screens
  3. Fault Screens
  4. Alarm Screens
  5. Inputs On Prints
  6. Outputs On Prints
  7. Internal Relays (B Coils)
  8. Fuses and circuit breakers

 

 

10.  Troubleshooting  Analog Control Circuits

  1. Whole numbers and  Floating Point numbers
  2. Troubleshooting Analog Inputs;
  3. Troubleshooting Analog Outputs
  4. Troubleshooting Analog Position Sensors  (LVDT) 
  5. Troubleshooting Pressure Sensors

 

11.  Troubleshooting Proportional Valves And Amplifiers

  1. Troubleshooting Proportional Hydraulic Valves For Pressure Control
  2. Troubleshooting Proportional Hyd Valves For Flow Control
  3. Troubleshooting Proportional Hyd Valves For Directional Control

 

12.  Troubleshooting and Set up of Proportional Control And Servo Systems

  1. Basic Servo System
  2. PID Control (Proportional, Integral And Derivative)
  3. Set up and Calibration of valves and amps

 

 

13.  Troubleshooting Advance Press Control Systems

a.  Advanced Types Of Pumps, Variable Volume Pumps

b.  Advanced Directional Valve Circuits

c.  Advanced Pressure Control Circuits

d.  Advanced Flow Control Circuits

 

 

14. Troubleshooting Pneumatic Circuits in Plastic Presses

a. Parts of the pneumatic circuit

b.  Pressure controls

c.  Flow controls

d.  Directional controls

e.  Electrical control of Pneumatic Systems

 

 

15.  Troubleshooting Specific Presses

a.  Most typical problems

b.  Troubleshooting flow problems

c.  Troubleshooting pressure problems

d.  Determining if the problems is Electrical, Hydraulic or Mechanical

 

16. Electrical and other Troubleshooting instruments and meters

This topic will be covered throughout all topics

a.  When and how to use a Voltmeter

b.  When and how to use an ammeter

c.  When and how to use an ohmmeter

d.  When and how to use a meggar (meg ohm meter) to test motors