Introduction to Automotive Stamping Automation Production Lines

1. Significance of Stamping Automation

Traditional manual production lines require lower initial investment, but as market demand grows their low efficiency and unstable product quality increasingly hinder enterprise development. Automated production lines address these issues by offering higher production efficiency, stable product quality, and lower unit cost under mass production. For large body-panel manufacturing, automated stamping lines show particularly significant advantages. Consequently, vehicle manufacturers typically plan large stamping lines with automation in mind.

2. Components of a Stamping Automation Line

In equipment terms, stamping automation lines typically consist of presses and automation systems. Here we focus on the automation part. A stamping automation system generally includes depalletizing systems, automatic transfer systems, and end-of-line discharge systems.

1. Depalletizing system

A complete depalletizing system typically includes two rail-mounted feed trolleys, each equipped with 4–8 adjustable magnetic separators (usually permanent magnets for sheet separation), a depalletizing gripper (robot or manipulator), conveyors (often magnetic belt conveyors), optional sheet washers and oilers, sheet-centering tables, and a control system. After a feed trolley returns to the depalletizing position carrying a stack (with or without pallets), the gripper picks sheets, transfers them via conveyors through washer and oiler to the centering station. After centering, sheets proceed to subsequent stamping operations.

2. Automatic transfer system

Automatic transfer systems move blanks or workpieces between processes. The two primary transfer mechanisms are manipulators and robots.

With advances in stamping automation, manipulator-based transfer mechanisms have evolved. Parallel four-bar manipulators are being replaced by high-speed, stable single-arm or dual-arm beam transfer mechanisms. Examples include Swiss Gudel Robobeam, former German MW Speedbar, and Komatsu H*TL systems from Japan—typical mechanisms for high-speed stamping lines.

Robotic transfer remains useful for line retrofits and lower-speed, lower-investment production lines due to its flexibility.

3. Double-sheet detection system

A double-sheet detection system identifies single or multiple sheets when the gripper picks material, preventing double feeds that could damage dies. Typically, a contact single-sensor detector is used during pick-up, while dual-sensor non-contact detection is applied during horizontal motion to protect dies and sheets. Market brands include Germany's Rolan and domestic leader Atonm.

4. End-of-line discharge system

The end-of-line discharge system includes discharge conveyors, lighting, inspection stations, manual or automatic packing mechanisms, and control systems. Its main task is to convey finished stamped parts to packing stations or automatic packers and provide conditions for inspection.

3. Main forms of stamping automation lines

Common forms include:

1. "Standard press + robot transfer"

Robot transfer offers high flexibility and ease of use at lower cost but has lower stability and speed, making it unsuitable for large-scale high-speed production.

2. "Standard press + single-arm manipulator"

Single-arm manipulators provide low cost and good flexibility and remain a practical option.

3. "High-speed press + beam-type transfer" (high-speed line)

Beam-type transfer provides high speed and stability and is widely used for large panel production.

4. "Multi-station press + step transfer"

Multi-station lines evolved from mechanical to electronic transfer control and now include single-slider and multi-slider configurations. Due to their speed and stability, they are widely used by manufacturers and often resemble high-speed production lines in characteristics.