Master–Slave Car Pallet Loading/Unloading System for Secondary Firing Line

I. Equipment Overview
1. The Master–Slave Car Pallet Loading/Unloading System is one of the core automation systems used in the production of high-grade wall materials. It plays a crucial role in the secondary firing process of modern clay brick plants, ensuring precise, efficient, and stable handling of wet and dried green bricks between the drying and firing sections.
2. This system is designed with a philosophy of intelligent control, accurate transmission, and stable performance. It integrates Siemens PLC centralized control with PROFIBUS fieldbus communication, enabling real-time data exchange between all intelligent units. Through an industrial computer platform, automatic parameter settings, process adjustments, data recording, and remote monitoring can be achieved.
3. The system is compatible with both pallet-type and strip-type (bar-type) conveying structures, adopting a master–slave car dual-layer transfer mechanism to efficiently transport wet and dry bricks between the drying section and the stacking section. It is suitable for the production of various products, including standard wall bricks, high-end decorative facing bricks, and multi-hole insulation blocks.

II. System Composition
The complete automation line consists of the following subsystems:
1. Servo Slug Cutting System – Precisely controls the length of clay slugs, ensuring perpendicular cutting faces and smooth operation;
2. Brick Cutting Machine – Dual-frame design with automatic wire change function; chamfering device optional;
3. Wet Brick Grouping System – Automatically detects and removes defective slugs and bricks to ensure product quality;
4. Wet Brick Loading System – Precisely places wet bricks onto pallets or bars with high positioning accuracy;
5. Pallet/Bar Conveying System – Transfers bricks smoothly to the master–slave car;
6. Wet Brick Pallet Stacking System – Automatically stacks and stores pallets in a buffer area;
7. Master–Slave Car Loading/Unloading System (Core Section) – The master car handles lifting, stacking, and transferring pallets or bars, while the slave car performs precise pick-and-place operations for automatic loading and unloading;
8. Dry Brick Pallet Stacking System – Automatically stacks dried bricks after exiting the dryer;
9. Dry Brick Unloading System – Unloads bricks to the grouping station with accurate positioning;
10. Pallet Return System – Automatically returns empty pallets/bars for reuse;
11. Dry Brick Grouping and Feeding System – Organizes and positions dry bricks for the stacking machine;
12. Automatic Brick Stacking System – Automatically stacks bricks on kiln cars according to set patterns, preparing for firing.

III. Core Technology: Master–Slave Car Pallet Handling System
This system adopts a master–slave car structural design, serving as the vital connection between the drying and stacking sections of the secondary firing line. It achieves fully automatic lifting, alignment, stacking, and rotation of pallets/bars through servo-controlled and laser-guided positioning — all without manual intervention.

1. Operating Principle:
• The master car runs on the main track, carrying and lifting entire pallet stacks;
• The slave car moves along the master car to perform precise insertion and extraction of pallets;
• Laser distance sensors and photoelectric detection ensure accurate alignment and stacking;
• The entire process is automatically coordinated by the PLC, ensuring smooth and synchronized operation.

2. Technical Features:
• Servo-driven lifting for high positioning accuracy and stable operation;
• Intelligent alignment system using laser and optical detection for automatic pallet positioning;
• High-speed layer switching with synchronized master–slave car operation;
• Compact structural design, saving floor space;
• Pallet tracking system for real-time monitoring of pallet ID and position;
• High safety level with multiple limit protections and anti-collision functions;
• Flexible expandability for different stacking heights and production rhythms.

IV. Product Features
1.Servo Cutting – Precise clay slug length, perpendicular cuts, low vibration, and smooth operation;
2.Brick Cutting Machine – Dual-frame design with automatic wire replacement; optional chamfering device;
3.Brick Grouping System – Automatically removes defective bricks and slugs to ensure quality consistency;
4.Single-Layer Drying – Effectively protects brick surfaces and prevents cracking;
5.Smooth Code Switching – Supports simultaneous production of different stacking patterns;
6.Flexible Clamping Tools – Compatible with standard and split clamping grippers for various brick types;
7.Multi-Program Control – Automatically switches control modes according to brick specifications;
8.User-Friendly HMI – Intuitive and easy-to-learn interface for operators.

V. System Control and Intelligence
1. Centralized Siemens PLC Control System
2. High-speed PROFIBUS fieldbus communication between subsystems
3. Industrial computer monitoring platform for parameter setting and real-time process control
4. Intelligent diagnostic and alarm system for preventive maintenance
5. Optional MES (Manufacturing Execution System) integration for digital management and full production traceability

VI. System Advantages

VII. Application Scope
This system is widely used in the following production lines:
1. High-grade clay brick production lines
2. Decorative facing brick production lines
3. Thermal insulation multi-hole block lines
4. New energy-saving wall material lines
It is the core automation equipment for achieving fully automated, intelligent, and energy-efficient production in modern brick plants.

VIII. Conclusion
The Master–Slave Car Pallet Loading/Unloading System provides a highly intelligent and precise solution for the automatic transfer and handling of wet and dry bricks in secondary firing production lines. By integrating advanced servo technology, PLC control, and intelligent scheduling, it significantly improves production efficiency, brick quality, and overall plant automation. This system serves as a vital component for brick plants aiming to achieve.