Fully Automatic Sheet-Metal Production Line

Introduction of the Line Components

1.1.1 Uncoiler & Leveler

Uncoiling / leveling line in operation.

The uncoiler and leveler feed coiled sheet to the laser machine after leveling. The main working host is composed of the uncoiling, leveling and servo sizing mechanisms.

While the machine is running, the uncoiler stays in the feeding state: the sheet enters the leveler, passes through the photo-eye-controlled looper and the steering correction mechanism, and then reaches the servo sizing device, which meters the sheet at the preset size and feeds it to the downstream laser. Once the servo feed reaches the set dimension, the machine stops feeding and signals the laser to start; after the laser finishes, the leveler/sizer continues feeding.

Feeding, leveling and sizing on the uncoiling/leveling unit are coordinated automatically and never stretch the sheet. The machine uses PLC servo control with a touchscreen human-machine interface; the operator simply enters the coil data. The touchscreen also provides feed-speed setting, automatic/manual changeover, feed-length setting, feed-count setting, auto-start and auto-stop buttons, pause button, counter reset, feed/retract buttons and abnormal-alarm indication.

Both the uncoiler and the leveler are designed to protect the sheet surface: chrome-plated rolls and polyurethane rolls prevent scratching. After the operator completes manual threading, the whole line runs automatically at all other times.

1.1.2 Laser Cutting Machine

Laser cutting machine.

The machine bed is welded from high-strength standard tubes. It is rough-machined after annealing to remove internal stress, then finish-machined after a second vibration-aging treatment. This eliminates welding and machining stress and greatly improves long-term machine stability. The machine is equipped with an automatic lubrication unit, a dust-removal and fume-extraction device in the cutting zone, and a scrap cart under the cutting area that can be pulled out periodically for cleaning.

The gantry is welded from one-piece high-strength manganese steel and aged, ensuring rigidity, strength, stability and vibration resistance. Compared with aluminium, steel plate offers higher strength and stiffness; with a well-designed structure, the steel beam gives excellent rigidity and stability during high-speed traverse, keeping the whole cutting process stable. Welding and machining are simple, and after heat treatment the beam reaches very high rigidity and strength.

The fiber laser cutting machine has a two-part air circuit. One part supplies the cutting gas to the cutting head — clean, dry compressed air, nitrogen and oxygen; the other supplies auxiliary compressed air for the zone cylinders and the worktable clamping cylinders used during zone fume extraction. The three cutting gases (nitrogen, oxygen, air) can be selected freely through the proportional solenoid valves.

1.1.3 Transfer Robot

BORUNTE transfer robot.

A long-reach, heavy-payload articulated robot is used to transfer sheets between the conveyor cart and the bending center. It is efficient and stable, with an all-servo drive system that saves energy.

1.1.4 Single-Axis Conveyor Cart

Single-axis conveyor cart on floor rail.

The single-axis conveyor cart is a movable unit driven by a three-phase motor that travels in one direction along a floor rail. Its functions are:

· Store sheets cut by the laser cutting machine that still require bending on the flexible bending center;

· Move sheets cut by the laser that do not need bending off the line through one-way travel of the cart;

· Store sheets produced outside this line that need bending on the flexible bending center.

The cart has a maximum load capacity of 5000 kg, which matches the beat of the flexible sheet-metal line: the laser cutting machine upstream and the flexible bending center downstream both stay in continuous operation, avoiding idle time on either machine and raising productivity.

1.1.5 Flexible Bending Center

D.K.Histron flexible bending center.

The frame is welded from high-quality steel plate and tempered, removing welding internal stress while keeping strength, so the machine will not deform in service.

The bending and clamping units are driven by servo power, ensuring bending force while reducing installation space. The sheet feed unit also uses servo motors to guarantee accurate feed.

The one-shot bending setup program adjusts all bending parameters in a single pass; afterwards the program is simply recalled for bending, with no need to re-adjust angle compensation or position compensation. The system also offers production-order query, automatic sheet-weight adaptation and remote diagnosis / upgrade service.

2. Technical Specifications

2.1 Uncoiler & Leveler

Raw Material Parameters

Other Parameters

Working process: the machine levels the coil and feeds it to the laser equipment; the main host consists of uncoiling, leveling and sizing mechanisms. After manual threading, the line runs automatically at all other times.

Equipment Composition & Main Drive Table

Equipment Configuration & Functions

This machine is a highly automated steel uncoiling, leveling and sizing laser production line for aluminium sheet of 1.0–3.0 mm thickness and 1000–1500 mm width.

· Loading cart: positions the coil on the uncoiler drum. V-type lifting rack pushed by hydraulic cylinders, guided by four guide columns; the cart platform moves along steel rails driven by a motor. 1 lifting cylinder Φ180×450 st; 1 travel motor (hydraulic motor); travel speed 6–8 m/min.

· Uncoiler: actively pays off or rewinds the coil. Single-support cantilever structure, three-segment drum with hydraulic expansion (Φ480–530 mm), driven by an AC motor through a reducer and chain drive; a disc brake at the tail of the main shaft provides uncoiling friction tension and stop braking. Equipped with a rubber-coated pinch roll moved by a hydraulic cylinder. Main materials: main shaft 45# quenched and tempered; sprocket 45# QT; sliding sleeve 45# QT; segments 45# QT. Standard parts: expansion cylinder Φ160×125 st ×1; pinch cylinder Φ63×300 st ×1; AC geared motor 3 kW, ratio 40.57, 1 set, inverter speed control for rewinding.

· Steering device: guides the sheet in line to prevent deviation. Vertical-roll edge guide type, consisting of side guide rolls, movable slide, screw guide and adjustment mechanism. Guide rolls Φ60, GCr15 hardened, chrome-plated; hand wheel adjusts guide width.

· Four-high leveler: precision leveling of coiled sheet. Parameters: 1 pair pinch rolls Φ100 mm with polyester rubber cover on top roll; 11 leveling rolls; working roll diameter Φ100; leveling roll material 45# (HRC52, hard-chrome plated, ground and polished); effective leveling width 1700 mm; leveling speed 0–20 m/min; main motor 11 kW. Structure: four-high, 11 rolls arranged 5 top / 6 bottom; entry and exit roll gaps adjusted separately by motors (entry gap smaller than sheet thickness, exit gap about equal to it); working rolls adjustable from −5 to +60 mm; rolls driven by motor through gear train.

· Lubrication system: gear boxes and reducers use oil-bath lubrication; other parts use dispersed heavy-oil lubrication. Grease: No.0-1 lithium-based grease; oil: N220 gear oil.

· Hydraulic and pneumatic system: hydraulic max. pressure 12 MPa, motor 5.5 kW AC, integrated pump station with valve blocks mounted on the oil tank and bed; oil N46 or N68. Pneumatic: air source provided by customer, 0.4–0.6 MPa, 1 m³/min; FRL unit, solenoid valves, piping and cylinders.

· Electrical system: 380 V 50 Hz; PLC centralized control; inverter drives for speed and positioning; operation modes: adjust / manual / automatic; operator stations: main console with touchscreen controlling the whole line, plus one wireless loading box. Functions: one-key start with multi-machine synchronization; fault diagnosis, status display and system protection; the whole line is logically and real-time controlled by PLC, and the pay-off motor speed can also be adjusted manually. Human safety is fully considered: reliable guards prevent misoperation, an emergency-stop button cuts power instantly. Two working modes (manual / automatic) allow single-machine operation or fully coordinated automatic line operation.

Main Component Brands — Mechanical & Hydraulic

Main Component Brands — Electrical

2.2 Laser Cutting Machine

Purpose: cutting the leveled sheet into blanks.

Structure: single-cycle platform type.

· High-strength manganese-steel welded frame ensures overall rigidity, strength, stability and vibration resistance;

· Hollow (light-weight) design of the work area greatly reduces accuracy loss caused by thermal deformation;

· Fully enclosed, sealed design with zone fume extraction completely isolates the cutting area from the outside;

· Imported servo units for stable performance;

· High-precision linear transmission parts for long life and stable performance;

· Imported reducers and high-precision helical gears for accurate, stable transmission;

· Shanghai BOCI laser cutting head for efficient cutting;

· Japanese HECHUAN pneumatic components;

· Internationally proven electrical components.

Material: cold-rolled sheet, galvanized sheet, stainless steel.

2.3 Single-Axis Conveyor Cart

Purpose: temporary storage of cut sheets / storage of non-cut sheets.

Structure: floor-rail moving structure.

· High-strength welded structure, max. load 5 tons;

· All-steel V-wheels, high load capacity and no detachment;

· Three-phase motor directly coupled to a reducer for strong driving force;

· Floor rail is surface-fixed, no need to excavate the floor;

· During normal line operation the platform stores cut sheets; non-cut sheets that need bending can be placed on the platform manually, so bending of non-cut sheet is supported.

2.4 Flexible Bending Center

3. System Introduction

3.1 Laser Cutting Machine

The CNC control program is the BOCHU professional intelligent control system, with automatic nesting, stable performance and fast operation. It supports common file formats such as DXF and PLT. The fast, simple operating system imports multiple cutting drawings with one click and gives precise cutting commands for a better user experience. Machine model: 3015 – 3000 W.

Main features of the control system:

· Friendly interface, easy to learn and convenient to operate; the CNC program is easy to edit and highly readable.

· Built-in cutting process parameter database; cutting parameters can be adjusted in real time during cutting for the best cut quality.

· Several optimized rapid-traverse modes with automatic auxiliary-gas shut-off during idle moves.

· Automatic cutting-head calibration, greatly improving Z-axis response speed.

· The cutting system supports jump (frog leap), laser power control, fly cutting, multi-axis synchronized control, etc.

Laser system hardware connection: servo motors, servo drives, BCS100E motion control board, industrial PC, DC 24 V power, laser source.

3.2 Flexible Bending Center

· Full closed-loop multi-axis EtherCAT bus control system, upgradable to 64 axes, seamlessly integrated, with 0.01 mm control accuracy; supports linear interpolation, electronic cam, electronic gear, synchronized follow-up, virtual axes, etc.; multiple tasks can run simultaneously and simulation can be run directly on the PC.

· Three-axis synchronized control with ultra-high synchronization accuracy.

· Multi-axis coordinated control with zero axis-to-axis synchronization error — leading bending efficiency in the industry.

· One-shot bending setup program: all bending parameters are adjusted in one pass, then recalled directly for production without re-adjusting angle or position compensation.

· Fully automatic machine-wide lubrication protects overall service life.

· Off-center-load visualization system prevents operator error that could cause eccentric load and reduce service life.

· Each bend includes rotation compensation and angle compensation modules: the operator only measures the left/right height and the bending angle of the edge to be compensated, enters them into the compensation unit, and the system calculates automatically and updates the bending data.

· Graphic programming error-check function; automatic avoidance of the pressure die and folding knife; machine coordinate power-off memory; mark-free bending.

· Production-order query, automatic sheet-weight adaptation, remote diagnosis and upgrade service.

· Customizable clamping gap, adaptive torque correction, cloud-shared database.

· Model import function.

· 3D and 2D drawing viewing function.

4. Main Component Configuration List

4.1 Laser Cutting Machine

4.2 Flexible Bending Center

5. Site Requirements from the Customer

· Power supply: 380 V, 50 Hz, fluctuation −5% ~ +10%. Where voltage fluctuates widely, the customer must install a voltage stabilizer; otherwise low-voltage electrical components may operate abnormally, suffer shortened life or damage, products may be scrapped, motors may alarm and stop, or the computer hard disk may be damaged.

· Air source: dry, clean compressed air above 0.6 MPa at a supply rate of 0.3 m³/min. If the air is not dry enough, the customer should fit a refrigerated dryer; otherwise moisture entering pneumatic parts increases piston friction, wears seals and causes leakage — and in winter icing accelerates pneumatic component damage.

· Ambient temperature: 0 °C ~ +40 °C. Below 0 °C, water-containing parts such as the oil/water separator and air tank may freeze, and lubricating oil becomes too viscous, reducing lubrication and causing component damage or failure.

· Ambient humidity: 20–80% RH （non-condensing）.

· Keep the machine away from strong vibration sources and electromagnetic interference. If it must be close, the customer should fit a filter; otherwise the screen may flicker, LEDs flicker, drives alarm, encoders malfunction, or nearby equipment may be disturbed.

· A dust-free environment free of harmful or corrosive gases.

· Foundation prepared according to the supplier’s foundation drawing.

· The customer should select trainees with senior-high-school education or above, basic computer skills, and availability for long-term placement at this position.

· Do not cut power while the machine is working; keep the voltage stable.