Flat pack sensors for welding and stamping applications
Welding and stamping environments are typically very harsh – hot, dirty with weld spatter, and damaging due to mechanical impact of stamping presses. Flat rectangular sensors (known as “flat packs”) are popular for these applications since mounting is more easily controlled than tubular sensors that could be threaded too far or too short in the machine.
If one sensor fails on a welding cell or stamping press, the entire machine cannot produce anything while the maintenance team addresses the issue. Productivity, performance and availability all are reduced during this downtime and the plant’s bottom line is negatively affected.
ifm’s flat pack design for detecting all metals (IQ2xxx inductive switches) or ferrous only metal (MQ2xxx magnetic switches) attacks this challenge in two ways:
- The robust metal housing of both families and the metal face of the MQ family provides enhanced durability with no additional cost.
- Information is available via IO-Link in real-time to predict a failure before it happens.
Holding up to the environment
Whether a blank is stamped for the first time or a part is moving through a progressive die, sensors will be doused with coolant and must continue to provide reliable results over time. ifm’s flat pack designs provide protection rating of IP65 / IP66 / IP67 / IP68 to withstand harsh environments.
Applications
Welding cells
A tooling nest holds a collection of parts firm while a welding robot completes the necessary welds. Typically, many sensors are used to confirm part presence and to ensure no parts move during the weld cycle. But, traditional sensors are subject to mechanical damage when loading and unloading the parts.
The flat pack design allows the sensors to be embedded in the tool itself to protect the face from impact. The all-metal face of the MQ2 family provides the most robust protection from mechanical damage at a price point below most plastic face sensors. Slag build up can be detected using the diagnostic functions of IO-Link so the sensor can be replaced prior to receiving false signals.
Stamping dies
Stamping dies contain precision-machined features to make complex parts quickly and efficiently. Repeatability in a stamping press is critical to avoid damaging the tool, which can lead to catastrophic downtime for a plant.
Accurate feedback from the die ensures:
- The die is safe and not drifting toward a crash.
- The blank is in the correct position for proper stamping of the part.
Technology overview
Inductive flat pack designs (IQ2xxx) operate similarly to other inductive sensors. The coil and capacitor form the basic sensor. Eddy current losses in metal targets create the switching signal.
Magnetic flat pack designs (MQ2xxx) detect ferrous only (steel) target by evaluating the change in the magnetic field. The following components refer to the magnetic technology image.
- connection
- housing
- shielding plate
- magnet
- active zone
- sensor chip
- steel target
Unlock sensor potential with IO-Link
Since a stamping die is a precision mechanical tool, sensors must do more than confirm a stripper plate is positioned correctly or a blank is properly placed for punching. Small guides such as bending points and short/long-feed feedback is essential to a high quality stamp that is safe for the press to engage.
Flat pack sensors with IO-Link are able to measure small sub-millimeter changes that can happen over time. Using IO-Link helps minimize the risk of unexpected downtime.
With IO-Link, the flat pack sensors can provide:
- Relative distance to target
- Number of power cycles
- Number of operating hours
- Automatic device replacement
