Diverse redundancy in screwdriving systems - ingenious marketing coup or concrete benefit for the user?
In screw assembly, there are numerous processes that should - and must - enable absolutely flawless screw connections. For example, in applications in the nuclear sector, in the aerospace industry or for safety-relevant screw connections in vehicles.
Initially, the chosen strategy or tightening technique plays a subordinate role.
Typically, the process is based on checking the assembly tool on a calibrated measuring device before each tightening process in order to detect or avoid deviations from the target value at an early stage.
An example
A mechanically triggering torque wrench that is set to the target value is "measured" on an external test device before being used directly at the tightening point.
The set value is compared with the displayed value. If the result is IO (OK), the tool is used immediately at the tightening point.
The same procedure is also used for high-quality, measuring EC screwdriving systems - and quite rightly so!
This is because no EC tool is absolutely error-free and the displayed value of the tool is not necessarily the actual value. A second, independent external measuring device is therefore always required.
Always? Not always!
In fact, there are already screwdriving systems with integrated monitoring sensors.
One example of this is the TBxEC2 cordless screwdriving system. Here, a rotating torque sensor works for high-precision screw fastening, while a static sensor monitors the measurement of the first sensor in real time.
In short:
An independent control unit is integrated directly into the assembly tool!
As the sensors used in this cordless screwdriving system use completely different technologies, this is referred to as "diverse redundancy" - to avoid systematic errors in the tool or during the screwdriving process.
What does this mean for the example above?
Today, there are technical solutions in screwdriving technology that significantly reduce the testing effort, even for highly sensitive applications.
The tool has a technically durable self-monitoring system that works even more precisely than simple measuring devices at the workplace - because the target values are checked live with every screw connection.
Practical advantages in series assembly
Such systems offer decisive cost and process advantages - especially in high-volume series production:
- Work steps in the assembly process can be reduced
- Assembly times are shortened
- Torque tolerances are minimized
- Productivity is maximized
- Test cycles can be extended from weekly to monthly or half-yearly, for example
In most industrial companies, this saving in time and effort clearly exceeds the additional costs for a tool with several sensors.
Conclusion
Try it out for yourself in your application - and then decide whether you can optimize your process, save costs and achieve higher quality and safety at the same time.