Scan on the official WeChat platform
As the global economy is more and more complicated, the transportation and logistics are more and more important, for manufacturers, traders, marketing departments and end users. Defuro sensors and motion control products provide many solutions in controlling, identification, monitoring and measurement and so on. They simplify the customer's logistics solutions.
Inductive sensor ensures safe position of load before starting platform lift and during operation
A platform lift for use in materials handling installations is fitted with inductive sensors to verify that loads are properly positioned before allowing the lift to move.
Cartons or pallets stacked on a lift platform in the down position may become unstable when the lift position changes. Also, if a load has any protruding parts, they may snag the edge of a floor as the lift rises or descends. This causes tipping, which can result in damage to both the load and the installation, with risk of injury to persons nearby.
A metal bar is fitted on the lift to ensure correct load position. Unless this bar has been pivoted into its cradle, the lift will not start. Also, any subsequent movement of the safety bar caused by an unstable load will stop the platform. Generally, this is a very simple electrical scheme with only AC power available on site. Mechanical limit switches were considered, but frequent switching wears out the mechanical contacts, while dust and moisture adversely affect reliability. The customer therefore seeks an equally simple, non-contact solution.
A Basic range inductive sensors from the Classics family (HS-C series), satisfies the customer’s requirements. To verify that the bar has cleared the load and lodged in the cradle, a 2-wire AC/DC sensor with 4 mm operating distance is embedded in the cradle itself. The sub-flush mounting position protects the sensing face from any mechanical contact. With a wide voltage range and short-circuit protection, these sensors also meet the customer’s on-site electrical requirements. Since the safety bar can become deformed with prolonged use, a sensor is chosen with an increased operating distance. This allows compensation for gradual target drift by simple range adjustment, rather than by repositioning the sensor itself.
The sensor closes an enabling circuit for the start button, which in turn latches a relay controlling the lift motor. Any movement of the safety bar caused by an unstable load will open the circuit and unlatch the relay, stopping unsafe movement of the platform.
No mechanical contacts to wear out
Non contact sensing
Immune to dust and moisture
Specific Product Advantages:
Easily replaced if damaged (connectorized)
Short circuit protected
Wide voltage range
Rugged Inductive Sensor Senses Position of Hoist Carriage on Dockyard Crane
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.
Loading and unloading containers in a busy British seaport is a 24-hour activity, all year round; optimum utilization of storage space is essential to achieve maximum operating efficiency. Container-handling cranes operate above the storage area, positioning containers before lowering them into place.
The hoist carriage on each crane travels along the length of the crane structure, traversing the width of the storage area to achieve complete coverage of the available storage space. OEM sensors fitted to the hoist carriage detect the ends of the structure, cutting power to the drive-motors and preventing the carriage from travelling beyond allowable limits.
Mechanical play in the drive system results in the carriage drifting laterally as it travels along the crane structure. The 15mm sensing range of the OEM devices is inadequate; occasionally, sensors collide with the crane structure, causing damage and interrupting operation. Replacement sensors with increased sensing range are needed to prevent collisions.
Defuro Basic range inductive sensors are highly suitable for this application. Mounted in rugged 40 x 40mm polyamide glass-fiber housings, these devices from the Classics technology family feature a 20mm sensing distance that eliminates the risk of collisions. these sensors are ideally equipped for the outdoor working environment of a seaport.
The use of industry-standard housings for the new Defuro sensors ensures that they are drop-in replacements for the original OEM devices. No modification to the mounting arrangements was necessary, incurring little downtime during the changeover to the new sensing arrangements.
Communication with the crane’s control system is via a PNP changeover interface, replacing the existing two-wire arrangement; a flexible PUR-sheathed cable provides the electrical connection. The new sensor features an integral M12 connector, allowing easy removal and replacement for maintenance.
A step improvement in operational performance was evident immediately after the new units were installed. The new sensors provide reliable sensing of each hoist’s position with no reported collisions since the date of installation. The customer has reported a marked reduction in crane downtime with an associated decrease in expenditure on replacement sensors.
Reliable sensing of hoist-carriage position in a busy container seaport
Significant reduction in crane downtime
Marked decrease in maintenance costs for replacement sensors
Specific Product Advantages:
Sensing distances up to 20mm in industry-standard 40 x 40mm housing
Scan on the public