Fault-free assembly is ensured and downtime minimized in automated facilities for high volume consumer goods assembly. Rugged inductive sensors detect the presence and position of equipment or components at each stage to ensure that parts are correctly aligned and ready for the next operation. Sensors must be accurate and responsive. In addition, an IO-Link interface offers the advantages of digital communication without the need for special cabling.
Manufacturers of consumer goods require reliable automation and machine control to eliminate assembly faults and improve efficiency. Tasks include: presence detection to initiate the cassette-change cycle in a stack feeder; position control for a rotary indexing table; pick-and-place gripper control; and presence monitoring on a conveyor system. Sensors must operate continuously at high speed under rugged industrial conditions.
Designed for demanding applications, Contrinex C23 Full Inox inductive sensors are a versatile, cost-effective and highly reliable solution.
Manufactured in V4A/AISI 316L stainless steel and rated to IP68/IP69K, these fully embeddable miniature inductive sensors offer a highly robust solution for the harshest operating environment. An industry-standard PNP or NPN output with either a PUR cable or an M8 pigtail connector ensures optimum flexibility. Additionally, IO-Link, a standardized point-to-point serial connection protocol for sensors and actuators, is enabled at no additional cost, offering the advantages of digital communication without the need for special cabling.
Stack feeders deliver base plates, electrical circuit boards and other planar components to assembly lines. In each stack feeder, a vertical cassette holds as many as 50 individual parts and a single inductive sensor monitors the status of each cassette. Once the final part is discharged from the stack, the cassette moves to its end position, triggering the sensor and initiating the cassette-change cycle. Contrinex C23 embeddable inductive sensors, featuring one-piece stainless-steel construction, are both robust and highly reliable. A 7mm sensing distance allows ample operating clearance, minimizing the risk of mechanical collision.
Conveyors deliver a continuous stream of parts to a rotary indexing table, which transports them in sequence to each assembly station. As the table rotates, sensors located at precise intervals around its periphery detect its exact angular position, bringing it to a halt once parts are correctly positioned for the next operation. With its best-in-class switching frequency of 180 Hz, the C23 inductive sensor is capable of high detection speeds, ensuring maximum production throughput.
At each assembly station, automated pick-and-place equipment adds components to the assembly. Dedicated transport mechanisms – including vacuum lifters, electromagnetic clamps and mechanical grippers – insert items swiftly and accurately in their designated positions. Embeddable inductive sensors play a key role in confirming the secure closure of custom-designed grippers before fragile, high-value parts are lifted.
On completion of the final assembly stage, finished units are discharged to a linear conveyor system. They travel to subsequent processing stages, including testing and packing. C23 Full Inox sensors, mounted directly above these conveyors, detect each unit as it passes below. This check not only confirms the presence of the assembled item at the expected height above the conveyor, but also measures throughput by activating a counting circuit in the customer’s control system.
Continuous operation is the norm in automated assembly plants. However, minor adjustments or tool changes may be required from time to time. In non-safety-critical areas, access hatches allow maintenance technicians to carry out these tasks without needing to interrupt production across an entire plant. Multiple sensors, mounted at intervals around the periphery of a hatch, ensure that appropriate warning signals are activated whenever the opening is not fully secured.
The Contrinex C23 series of Full Inox inductive sensors has the capability to communicate remotely with a plant-wide control system, thanks to implementation of the IO-Link protocol on PNP normally open devices. In a typical automated plant, each assembly line runs continuously throughout the day, with remote diagnostics eliminating the need for manual intervention in almost every situation.
Designed to simplify integration, IO-Link sensors are compatible with all IO-Link master versions, allowing set-up and diagnostics to be conducted centrally. Interrogating a device returns its manufacturer ID and product ID, allowing systems integrators to determine remotely that the right sensor is in the correct location. Contrinex C23 inductive sensors additionally feature an on-demand self-test function that confirms full capability at all times.
For the C23 inductive series, alternating between normally open and normally closed functionality via remote output-mode configuration is a standard feature of the IO-Link protocol. Systems designers also have the capability to modify the output signal. Delaying the switching pulse accommodates any travel time between a sensor and its corresponding actuation point, while stretching the pulse ensures that slave devices with lengthy response times trigger reliably, even at high throughput rates.
Finally, each sensor provides an output-status check derived from its factory calibration data. If the output signal from a sensor falls outside a range that corresponds to a sensing distance between 80% and 100% of its nominal value, an alarm flag is triggered, highlighting the need for investigation. For plant managers under pressure, peace-of-mind is a valuable benefit.
The no-cost option of the industry-standard IO-Link protocol ensures that best-in-class performance is coupled with ultimate ease of use in even the most demanding circumstances.