Connectors

Thursday, July 25, 2013

Tags :  electronics

Top-level motorsport now demands that electrical faults can no longer cause retirements or loss in car performance. For Formula One, the exponential rise in electronics in means that connecting up the various sections of loom to the ECUs and sensors has become critical.

In recent years this connectivity has been driven by new systems, such as a standard ECU and KERS. There is then a further rise in complexity as the new 2013 ECU has an even greater capacity for sensors. Then next year the cars will have far more complex engines and energy recovery systems, driving even more complication in the cars’ cabling.

Connector technology has progressed immensely over the years; as soon as on-car electronics became common, the need to move from simple spade or block connectors to the multi-pin Military (Mil-spec) type of connectors became apparent. But such are the demands for space and performance in Formula One that the common Mil-spec connectors were soon not up to the job.  Demands for smaller connectors with denser pin arrangements, all with lower weight, drove the connector industry to develop bespoke motorsport ranges during the 1990s.

Most current connectors are made in aluminium, with the connector pins being gold-plated. The mated pair of connectors are secured with a bayonet-type fitting and, once closed; they are environmentally sealed to prevent the ingress of dirt or moisture.

Although they are not made to Mil-spec standards they are still subject to the same tests to ensure they can withstand the harsh environment of moisture, heat and vibration. Unlike Mil-spec connectors they do not use a screw thread fitting to hold the loom to the connector; instead heatshrink adhesive-lined boots are used. For harsher environments, such as the gearbox, vibration-resistant connector variants are available. 

Connector types

Throughout the car, specific connector formats are needed to package the required density of connections in the space available.

The various ECUs, power, ignition and telemetry control boxes all use specialised high-density connectors to interface with the other devices on the CANbus. With the advent of KERS and direct-injector technology, connectors beyond the usual scope of commonly found connectors are required. For these applications new connectors are being developed to cope with the high current demands.

One common connector is the steering wheel-to-column interface. To allow rapid and repeated removal of the wheel, a special connector pair is designed to fit into the end of the steering column and the back of the steering wheel.

A similar requirement is for the nose cone, which is frequently removed for access to the footwell of the car. The electronics inside the nose, such as the Formula One management (FOM) cameras, ride height sensors and pressure sensors need a connection to the main wiring loom, so a connector is required to break the loom between the car and the nose. A specific blind mating connector is used, which allows the refitting of the nose without risk of damaging the connector’s pins, even if the connectors are misaligned in three axes.

Also, the pit umbilical cable has a bespoke connector to mate to, and this is fitted inside the cockpit to allow the car to join the local computer network inside the pit garage.

Inside the fuel tank, special hermetically sealed connectors are used to connect to the various pumps and sensors to the car’s main loom.

The gearbox and its electro-hydraulic control systems demand robust sensors to cope with its harsh environment

Written by Craig Scarborough

Leave your comment