Special-purpose machines exploit the versatility and convenience of sensor technology for tasks that range from simple position sensing to complex feature detection and identification, in applications as diverse as electronic assembly and plastic molding. Sensor adaptability is also crucial to the economics of one-off and customized machine production.
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.
During semi-automated heat staking of assemblies for domestic white goods, manufacturers use light curtains to preserve operator safety without compromising production throughput. The active optoelectronic protective device (AOPD), mounted directly in front of each bench-mounted heat-press, prevents the press-head from descending if it detects any intrusion in the working area, halting the operating cycle immediately.
A plastics manufacturer tests batches of control knobs for in-car audio systems before shipment to automotive assembly plants; each knob contains a small metal washer that occasionally becomes dislodged. A custom-built testing machine tests a tray of 70 knobs in a single cycle; long-distance inductive sensors, positioned directly below the knobs, confirm the presence of a washer in each assembly.
Stainless-steel-braided hydraulic hoses for water heaters undergo over-pressure testing at the final stage of manufacture. Before pressure is applied, a multi-sensor system checks each hose assembly to ensure that the correct mechanical parts have been fitted. Applying high pressure to an incomplete assembly could result in catastrophic failure, damaging test equipment and putting operators at risk of injury.
To monitor the speed of industrial composting machines, robust and reliable FULL INOX sensors operate continuously inside the rotor, withstanding dust, humidity and high temperatures. Fast drying of materials, optimal decomposition and reliable sanitization are assured.
Straddle carriers, purpose-designed container-handling vehicles, operate in highly aggressive seaport environments, necessitating frequent preventative maintenance. To measure wear in components with a high risk of premature failure, European port operators use rugged, analog-output inductive sensors. Monitoring the condition and wear rate of each component enables predictive maintenance to be undertaken only when necessary, maximizing vehicle utilization and reducing maintenance costs.
At busy container seaports, purpose-designed container-handling vehicles operate around the clock, loading, unloading and stacking containers. Space utilization is increasingly important and correctly identifying the size of container picked for each lift is essential. Fitting vehicles with sensors that detect the container size eliminates the need for drivers to carry out identification checks, saving time and avoiding errors.
Container-handling cranes in busy British seaports operate around the clock. Sensors on each hoist carriage detect its position with respect to the crane structure and prevent it travelling outside preset limits. Mechanical play in the hoist carriage allows a small amount of lateral drift as it travels along the crane structure; adequate sensing distance is essential to prevent the sensor colliding with the crane structure.
A manufacturer of bulk material-handling equipment uses Radio Frequency Identification (RFID) technology to sense the position of a large rail-mounted reclamation-conveyor operating in a hot, dusty environment. A pair of read-write modules, mounted on the machine structure, interrogates a series of RFID tags, positioned at one-meter intervals along each travel rail. The control system identifies each tag individually and determines the exact position of the machine.
A Swiss meat-processing plant uses non-contact ultrasonic presence sensing to increase productivity and eliminate breakdowns when washing empty meat bins. A single ultrasonic sensor, mounted above the conveyor on which the bins travel, checks for meat residues, rejecting any contaminated bins before the wash station. Old, contact-based systems were unreliable, resulting in breakdowns and frequent interruptions to the washing process.
Zinc is produced by electrolysis, during which acidic vapors are generated. This harsh environment severely limits the lifetime of sensors used for positioning cathodes in the electrolyte. By using a special type of steel for the sensor housing, long sensor life is achieved.
A leading producer of powered handling components for the automation industry supplies gripper systems to end-users throughout the world. To ensure maximum flexibility and reliability for end-users, particularly regarding space constraints when mounting the grippers, Series 300 miniature (3 mm diameter) inductive sensors are supplied as an accessory.
A German company specializes in x-ray systems for evaluating weld seams in pipes. X-ray systems provide manufacturers with the most comprehensive data, but precise control of the distance between the x-ray source and the surface of the pipe is critical for imaging data quality.
An induction heating plant supplier has developed a patented system for cooling inductive proximity switches in a ceramic tube. This allows normal commercial sensors to be used in extreme, high-temperature applications. In this cooling system application, Contrinex Series 700 outperformed other commercial inductive sensors.
A small book press uses Safetinex light curtains for finger protection to monitor the press opening. Whenever a person’s hand is detected between the sender and the receiver unit, the book press will not operate; hence it will not present any hazardous situation to the operator.
A tannery uses Safetinex access control barriers to protect the entrance to its automated stock handling area. Safetinex access control barriers detect any operator entering the area and stop the leather stock moving at high speed in the automated handling system. Furthermore, damage to company vehicles and the stock handling installation itself is also avoided.
A German supplier of automated laboratory equipment for in-vitro diagnostics exploits the long operating distance and high resolution of analog Series 3#30 photoelectric sensors to detect the 1 mm signal bounces that indicate where the cap sits on the test-tube.
A manufacturer of injection molded parts for the automotive industry uses inductive sensors from the Extra Distance family (500 series) to check that threaded inserts have been correctly mounted inside molded plastic parts. This ensures zero-fault delivery to the automobile producer.
When performing robot-assisted laparoscopic surgery, surgeons use sensors to verify that a cannula or trocar of the correct length and diameter has been loaded in the robotic member before insertion into the body cavity.
A manufacturer of dancer systems for web tension control uses an inductive sensor with analog output to register constant, small changes in web tension and transmit them to the tension control system, which in turn provides continuous feedback to a variable speed drive.
A US manufacturer of aerosol cans needs to ensure that, for each can, only one bottom is inserted into the press that applies and crimps the bottom to the can body. This checking must be accomplished without physical contact while the product is moving.
A German manufacturer of industrial timing belts uses inductive sensors with analog outputs to measure the position of steel reinforcing bands during continuous production. Two long-range, high-resolution sensors, mounted above the extruded belt profile, give real-time positional data. The customer’s process-control system monitors the analog voltage outputs, alerting the operator and halting production if the values are outside allowable limits.
A Malaysian manufacturer of PC motherboards uses presence sensing immediately after reflow soldering to trigger a subsequent operation. A long-distance inductive sensor is mounted above the exit conveyor of the reflow oven and detects each motherboard as it passes out of the oven. The customer’s control system accepts the NPN sensor output, initiating the next process stage.