Technical Specifications

• Cargo: Standard sheet-metal box trucks with a forklift pocket
• Capacity: up to 20 cars per hour
• Weight per unit: max. 500 kg
• Travel range: approx. 7,500 x 7,500 mm
• Tilt angle: approx. 170°
• Lifting height: approx. 1,800 mm
• Covered entrance hall
• Enclosure and sectional door serving as an airlock (for personal protection and climate control)
• Drives: SEW frequency-controlled gearmotors, ABUS overhead crane systems
• Control System: Siemens S7-312C

Function

Valuable stainless steel machining scrap is generated at the various automated production machines throughout the company and is collected directly into designated sheet metal carts. The machine operators then transport the full carts to the central collection point.

There, the employee takes an empty cart and pushes the cart to be emptied into the transfer chute. After pressing the start button, the employee can step away, as all subsequent steps take place automatically. First, the sectional door closes, and the vertical lift raises the chip cart to a transfer position.

Here, the panel van, standing on a load carrier, is picked up by a gantry crane. The gantry crane, equipped with a tipping unit, moves the van over one of two scrap containers—either of which can be selected—and uses an integrated ultrasonic measurement system to determine the optimal drop-off position for maximum container fill.

The rotational movement required to empty the box truck is performed by a controlled central drive and was optimized during commissioning—in terms of angular velocity and vibration—to match the actual behavior of the chips. After unloading, the chip cart is transported back to the transfer chamber and is ready for manual unloading. A traffic light signals when it is ready.

Design Details

A simple grid-based configuration for the discharge points would have resulted in poor space utilization in the scrap container due to varying levels of wagon fill and widely differing chip densities. An ultrasonic sensor mounted below the dumping unit is therefore positioned above the last discharge point to determine the current fill level there as a criterion for the next discharge point. This is the only way to ensure that there are no “chips hills” and “chips valleys” in the container.

The Control System

A Simatic S7-312C PLC controls the system. All linear and rotary drives are controlled by SEW Movitrac or MoviMot inverters. A mobile operator panel is available for manual operation of the system; when needed, it can be plugged in at a location within the system’s field of view. A remote maintenance connection allows us to assist the customer with troubleshooting or to implement software modifications based on customer requests at a low cost.