Automated screwdriving
It is one of the cornerstones of modern assembly, particularly in the automotive, electrical engineering, and aerospace industries. It has long since ceased to be merely a matter of "simply turning a screw," but rather a precise, data-driven process.
AUTOMATED SCREWDRIVING
WHY AUTOMATE
The main considerations today are not just speed and labor savings, but above all quality of workmanship and traceability.
- Repeatability: The machine applies exactly the same torque every time, eliminating human error.
- Ergonomics: automated systems absorb reaction forces that would otherwise strain the operator’s wrists and joints.
- Data collection: every tightened joint has its own “digital footprint”—it is precisely known at what torque and at what angle it was tightened. This is critical for safety-critical joints (e.g., car brakes).
KEY TECHNOLOGIES AND PARAMETERS
Our solution relies not only on a mechanical clutch but also on servo motors and digital controllers.
TORQUE AND ANGLE CONTROL
During advanced tightening, two main variables are monitored:
1. Torque: the force with which the bolt is tightened.
2. Rotation angle: monitors how much the screw has rotated after the head has seated. This helps detect errors such as a missing washer or stripped thread.
SCREW FEEDING METHODS
For the process to be truly automatic, screws must be continuously fed to the machine:
- Vibrating hoppers: The screws are oriented by vibrations and travel through a tube to the tightening head.
- Step feeders: Gentler on the screw surface, quieter.
- Pick-and-place: A robot picks up the screw itself from a precisely defined position.
TYPES OF AUTOMATED SYSTEMS
| SYSTEM TYPE | CHARACTERISTICS | APPLICATION |
| Manually controlled tool | The operator holds a smart screwdriver connected to a controller. | Flexible assembly, diverse products. |
| Stationary units | Tightening spindles permanently integrated into the production line. | High-volume production (e.g., motors). |
| Robotic workstation | The tightening head is mounted on a robot or cobot arm. | Complex shapes, high precision, changing positions. |
TRENDS: INDUSTRY 4.0 AND COBOTS
In recent years, there has been a shift toward smarter solutions:
• Collaborative robots (Cobots): equipped with tightening heads, they work directly alongside people without the need for safety cages.
• Smart bit attachments: sensors directly in the attachment can detect whether the bit is worn out or whether it has seated correctly in the screw slot.
• Predictive maintenance: the system itself reports an impending spindle failure based on vibration or temperature analysis during the cycle.
