1. Frame & Layout Topology
The main line frame is fabricated via bending and welding of 40×40 mm high-strength galvanized square tubes (wall thickness ≥ 2.0 mm) and standard channel steel. The entire frame undergoes anti-rust spraying treatment, with a static load capacity ≥ 150 kg per meter. To adapt to the rectangular space of large household appliance manufacturing workshops, the line adopts a closed-loop or U-shaped layout incorporating 90° curved transition sections. Reinforcing rib frameworks are fitted on the outer side of curved segments to prevent structural deformation during fully loaded turning operations.
2. Core Conveying System (Heavy-Duty Roller Conveyor)
Discarding conventional belt conveying, the core transmission consists of Φ50 mm heavy-duty galvanized idler rollers with knurled or rubber-coated surfaces (friction coefficient μ ≥ 0.4), which prevents horizontal cylindrical products from rolling on inclined workstations.
- Drive Mechanism: Heavy-duty powered rollers with built-in planetary reduction motors are installed at curved bends and the ends of straight sections. Flange mounting ensures coaxiality ≤ 0.1 mm.
- Direction Change & Transfer: For the 90° corners shown in drawings, rollers are arranged in a staggered pattern or conical rollers are adopted. Products turn smoothly by gravity sliding without additional power input.
- Buffer Supports: Height-adjustable anti-static foam support pads (or PE foam clamping grooves) are standardly equipped between roller gaps to hold up the bottom of water heaters, avoiding cylinder sagging and paint surface scratches. Support heights can be quickly replaced to fit cylinders of different diameters.
3. Workstation Facilities & Electromechanical Auxiliaries
- Modular Hanging Panels: Vertical posts beside each workstation are equipped with double-sided tool hanging boards, integrated with 24 V / 220 V industrial sockets and dual air-circuit quick couplings (Φ8 mm) to meet the instantaneous high airflow demand of pneumatic tools.
- Manipulator Integration: Cantilever pneumatic balance cranes (rated load: 50 kg–100 kg) are arranged longitudinally along the line to assist operators in precise lifting and positioning of high-inertia components including heating tube assemblies and electric control boxes.
4. Informatization & Error Prevention (ATE & MES System)
- Integrated Testing Architecture: Industrial terminal blocks and aviation plug matrices are mounted above workstations.
- Electrical Safety Testing: Withstand voltage testers and earth resistance testers are integrated. Probes or clamps automatically connect to the residual current device plug and metal casing of water heaters. The workstation will be automatically locked if safety thresholds are not satisfied (e.g., withstand voltage 1500 V, leakage current ＜ 5 mA).
- Air Tightness Test Interfaces: Communication protocols (RS485 / IO triggering) for micro-pressure / high-pressure air tightness test chambers are reserved. Test curves can be automatically bound via barcode scanning to enable digital judgment of leakage rate, compliant with national standard GB 4706.12.
5. Tooling Fixtures
Custom EVA foam molds or nylon guide strips are adopted, contoured and molded according to the outer diameter of water heater cylinders. Fixtures are designed with positioning grooves for drain pipe connectors and fool-proof structures for magnesium rod mounting holes, limiting the positional tolerance of accessories within ±1 mm during transportation.
6. Core Technical Parameter List
| Item |
Specification |
| Rated Load |
≥ 100 kg/m (full-load roller bearing capacity) |
| Conveying Speed |
0.5–10 m/min (stepless variable frequency speed regulation) |
| Roller Specification |
Φ50 mm seamless steel pipe, wall thickness 1.5 mm |
| Main Control System |
Siemens S7 Series PLC + Touchscreen HMI |
| Communication Protocols |
Ethernet/IP, Modbus RTU |
| Power Supply |
AC 380 V / 50 Hz, 3-phase 5-wire system |
| Air Source |
Clean dry compressed air, 0.6–0.8 MPa |
Summary
This assembly line is custom-developed for horizontal cylindrical household appliances (storage-type electric water heaters, horizontal gas wall-hung boilers). Combining heavy-duty roller mechanisms with curved transition structures, it effectively solves the challenges of anti-slip, anti-rolling and stable turning for heavy cylindrical workpieces on production lines. Equipped with modular test interfaces and anti-static support systems, it delivers highly reliable manufacturing covering pre-assembly, wiring and comprehensive safety inspection. Flexible customization is available based on customers’ specific cylinder outer diameters (Φ400 mm–Φ800 mm) and workshop CAD drawings.
