Sumitomo Demag E220: Ejector Forward Timeout — Hydraulic vs Electric Ejector Diagnostics

Sumitomo Demag Alarm E220 triggers when the ejector plate fails to reach the programmed forward position within the timeout period. This alarm stops the cycle before the mold closes on extended ejector pins — preventing catastrophic mold damage...

Sumitomo Demag Alarm E220 triggers when the ejector plate fails to reach the programmed forward position within the timeout period. This alarm stops the cycle before the mold closes on extended ejector pins — preventing catastrophic mold damage (crushed ejector pins, damaged core pins, sheared ejector plate guide pins, or cracked mold plates).

Root Cause Analysis by Machine Type

Hydraulic Ejector Systems (SE-DUZ, SE-HD, SE-HS series): (1) Low hydraulic pressure: check ejector circuit pressure at the directional valve — compare to specification (typically 70-100 bar). Low pressure can be caused by worn hydraulic pump (check case drain flow), leaking ejector cylinder piston seals (internal bypass — the cylinder extends slowly under no-load but stalls under ejector load, and drifts backward during the timeout period), or a stuck-open ejector circuit pressure relief valve. (2) Ejector cylinder rod binding: mechanical interference from misaligned ejector plate guide bushings, insufficient lubrication of the ejector plate sliding surfaces (grease zerks accessible from the operator side — lubricate every 50,000 cycles or weekly, whichever comes first), or a bent ejector rod from a previous crash. (3) Ejector plate stuck/sticking: check for polymer or debris accumulation under the ejector plate (purge guards should prevent this but are often removed for cleaning and not reinstalled), or insufficient mold release causing the ejector system to stall against a stuck part.

Electric Servo Ejector Systems (SE-EV, SE-EL series): (1) Servo motor overload: the ejector servo drive reports an overcurrent or overtorque condition. Check the servo drive diagnostic display — the peak current draw during the failed eject cycle indicates whether the motor is stalling (high current, no motion = mechanical bind) or never receiving the command signal (no current, no motion = control system fault). (2) Ejector belt/ballscrew wear: the timing belt connecting the servo motor to the ejector ballscrew may have jumped teeth, or the ballscrew nut may have excessive axial backlash (>0.05 mm — check with a dial indicator on the ejector plate), causing the actual ejector position to lag the commanded position. (3) Servo drive parameter corruption: the ejector axis acceleration, deceleration, or maximum torque parameters may have been inadvertently changed. Compare current parameters to the machine's backup parameter list (stored on the NC controller's CompactFlash card or the machine builder's parameter sheet).

Alarm Details

Troubleshooting Protocol

Equivalents & Cross-References

Related Diagnostics & Materials

References & Industry Standards

• ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
• UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
• MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
• ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org