Automated stacking device for silicon steel sheets after stamping

Comprehensive Description of the Post-Punching Silicon-Steel Lamination Automatic Stacking & Arranging System
(Main sections now labelled A–E)

A. Functional Modules

1. High-speed lamination feeding / straightening unit

• A chute or vacuum belt receives each lamination from the press, decelerates it and avoids scratching.
• Dual-servo edge knockers align the sheet in X and Y within 0.2 mm.

1. Vision positioning & defect inspection

• 2–4 off 5 MP industrial cameras plus coaxial LEDs capture every sheet within 30 ms, checking locating holes, V-notches and burrs.
• Software outputs angle error (±0.05°) and centre offset (±0.05 mm). NG sheets are blown into a scrap box.

1. Pick-and-sort robot

• Lightweight high-speed SCARA or Delta robot carries a Bernoulli (non-contact) + vacuum (grip) hybrid end-effector to avoid double picking.
• Repeatability ±0.02 mm; cycle ≤0.6 s/lamination (example: 45 mm × 95 mm E-piece).

1. Stacking table with variable-pitch locating pins

• Removable pins automatically adjust spacing for different core cross-sections; pin-to-hole clearance 0.05 mm.
• Load cells or magnetic scales below the table count sheets and monitor stack height, alarming if out-of-limit.

1. Auto column change & unloading

• When the preset number of sheets is reached the table rotates or shuttles the full column to a strapping station while an empty pallet continues stacking—no operator needed.
• Can dock with an automatic strapping + welding machine for finished-core unloading.

1. Control & MES interface

• EtherCAT bus synchronises up to 32 axes; OPC-UA / Modbus-TCP ports upload counts, cycle time and fault codes to factory MES.

B. Workflow (typical cycle)

Press outlet → chute deceleration → vision shot (OK/NG) → robot pick (with offset correction) → stacking table (guided by pins) → height check → full-column change → strapping / welding → AGV carries finished core away.
Line cycle: 0.8 s/sheet (including 10 % NG redundancy). A 1 200 mm leg of about 1 500 laminations is finished in ≤25 min.

C. Key Technologies

• Multi-profile soft jig: independently regulated vacuum zones handle E+I, mitred/step-lap joints, etc.; change-over ≤10 min.
• Servo-driven variable-pitch pins: ball-screw + linear-motor hybrid, 150 mm travel, repeatability ±0.01 mm, covers 3/5-leg transformer windows.
• Low-damage pick-up: Bernoulli pad lifts 0.3 mm sheet with 0.5–0.8 N before light vacuum locks it, eliminating dents and buckling.
• Double-sheet / corner-broken algorithm: edge extraction + laser thickness check gives ≥99.5 % double-sheet detection, avoiding height errors.
• Digital twin & self-learning: offset data are collected to train an on-line compensation table; after 1 h continuous running stacking accuracy improves 15 %.

D. Main Performance Indices (reference)

• Stacking accuracy: inter-sheet misalignment ≤0.05 mm; total leg height error ±0.15 mm / 1 000 mm.
• Surface-defect escape rate: <0.1 %.
• Equipment availability: ≥92 % (three-shift basis).
• Noise: ≤72 dB(A).
• Power: average 4 kW, standby ≤0.8 kW.
• Footprint: single-leg machine 2.8 m × 1.6 m; 3-leg parallel machine 4.5 m × 2.2 m.

E. Benefits

1. Labour: a core line that needed 6–8 operators now needs one patrolman.
2. Productivity: stable stacking cycle 3–5× faster than manual.
3. Loss reduction: no hand pinching, bending or sweat corrosion; core loss typically drops 0.06 W/kg.
4. Traceability: each lamination ID is linked to its vision image; performance deviations can be traced to the exact layer.
5. Fast profile change: recipe parameters + exchangeable templates let a new product be introduced in 0.5 day instead of 3.

In short, the post-punching silicon-steel lamination automatic arranging system combines high-speed straightening, vision inspection, robot picking, precision-pin stacking and automatic column change to deliver 0.05 mm-level accuracy at 0.8 s cycles, making it a core machine for digital transformer and motor factories.