Rugged Inductive Sensor Detects Straight-Ahead Position of Rear-Wheel Steering


A range of Swiss-manufactured, multi-purpose off-road tractors allows the driver to choose between two-wheel or four-wheel steering; when selecting two-wheel steering via the front wheels only, the rear axle is locked in the straight-ahead position. Before the axle is locked, rugged inductive sensors from Contrinex detect the straight-ahead position accurately and reliably, ensuring precise alignment of the steering geometry

Customer Values

  • Reliable, repeatable sensing performance in demanding operating conditions
  • Fit-and-forget operation with minimal maintenance
  • Technically elegant, cost-effective solution requiring minimal re-engineering

Specific Product Advantages

  • Rugged, robust stainless-steel sensor with integral M8 connector
  • 2mm sensing distance eliminates possibility of accidental damage
  • Affordable high-performance sensor with exceptional reliability

Inductive BASIC

Contrinex BASIC inductive sensors have a worldwide and well-deserved reputation for uncompromising accuracy...

Customer Application

Modern multi-purpose off-road utility vehicles are exceptionally versatile, offering four-wheel drive and both front- and rear-wheel steering. Reliable operation all year round, on all types of terrain and in all weather conditions, is essential; typical tasks include bulk-load transportation, agricultural engineering and snow clearance. Extreme conditions often demand increased maneuverability; for maximum control, the driver can engage four-wheel steering when required. When reverting to the default two-wheel steering configuration, the rear axle must be locked in the straight-ahead position to prevent misalignment of the rear wheels. A rugged, reliable and accurate sensor system is required to detect the straight-ahead position of the rear axle before it is locked. The sensor must withstand significant mechanical shock and vibration and must also be impervious to water ingress. Additionally, it should accommodate the extremes of temperature experienced during all-year-round operation.

Customer Solution

Inductive sensors from the Contrinex Basic range are rugged, reliable and accommodate the required extremes of temperature; an M8-sized type is ideal for this application. With its body in V2A/AISI 303 stainless-steel and vacuum-encapsulated electronics, it is particularly suitable for the mechanically demanding environment, and it is rated for operation at temperatures between -25oC (-13oF) and 70oC (158oF). A narrow flange is attached to each end of the vehicle’s hydraulic power-steering rack; the sensor is mounted immediately below one end of the rack and detects the position of the flange as it passes over the sensing face. The sensing distance of 2mm eliminates any possibility of accidental collision with the flange. Configured with an industry-standard PNP normally-open interface, the sensor features an integral M8 connector and connects to the vehicle’s central controller via a flexible PVC-sheathed cable. Adding the sensor requires minimal modification to the vehicle’s control systems, and maintenance is simple and speedy. The sensor detects the straight-ahead position of the vehicle’s rear axle repeatably and accurately, ensuring correct, reliable engagement of two-wheel steering. Contrinex inductive sensors provide the customer with a cost-effective fit-and-forget solution to a challenging problem.