Ignition lock
The ignition lock is used to secure motorized means of transport against unauthorized use.
purpose
Otto engines require permanent electrical ignition. If this is interrupted by the ignition lock, the engine comes to an immediate standstill or it cannot be started. An exception are vehicles that are equipped with an engine run-on circuit . Under certain conditions, this technology provides the ignition system with power even when the ignition key is removed.
Diesel engines do not need an electric ignition as compression ignition, but the terms ignition , ignition key and ignition lock are also used here . If the key switch is operated on this type of engine, a solenoid valve opens the fuel supply to the fuel pump and the engine can be started. If the "ignition" is switched off, the solenoid valve blocks the fuel supply and brings the engine to a standstill.
Key positions
The ignition lock often combines several functions. See switch positions on the photo "Illuminated car ignition lock".
- (LOCK) , from English for locking or locking. Steering wheel lock and steering wheel lock are active.
- (ACC) identifies the first level of power supply in the vehicle, which comes exclusively from the starter battery , for example for operating a radio. The term ACC stands for Accumulator or Accessory, English for accessories.
- (ON) : Power supply for ignition and engine consumers are switched on. This is the normal operating position after the engine has been started. For vehicles with a diesel engine, the same preheating position and release of the fuel supply to the high-pressure part of the injection pump .
- (START) : Switching on the electric starter . A spring-loaded contact resets the ignition key to the ON position when it is released.
The designations of the key or switch positions of an ignition lock are not standardized. In addition to the designations listed above, Roman numerals can also be used as identification. With some makes, the key positions are not marked at all.
Many ignition keys also have a transponder system that unlocks the immobilizer .
developments
The spring-loaded START key position is increasingly being omitted in cars and is being replaced by a separate starter button . The complete ignition lock is increasingly being replaced by chip card systems, keyless go and fingerprint recognition systems. Safety aspects are named as the main reason, since the ignition key poses a significant risk of injury to the driver's knee in an accident, which is why Saab moved the ignition lock to the center console a long time ago.
Ignition switch
An ignition lock usually consists of two components. A mechanical lock with a locking cylinder to ensure that only the key that matches this lock can perform the switching process. An electrical switch is attached to the mechanical lock cylinder, which actuates an electrical contact depending on the key position. The switch is often only accessible by dismantling the mechanical part of the ignition lock.
Installation position
Passenger cars
In passenger cars and also in various commercial vehicles , the ignition lock is usually located on the side of the steering column or on the center console . Most types of vehicle are installed on the right of the steering column.
- Left- hand drive with ignition lock to the left of the steering column
are u. a. Porsche 356 and 911 , Citroen DS , Lada Niva , Fiat Ducato first generation from 1982 (type 280/290).
motorcycles
On motorcycles, too, the ignition is switched on with the ignition lock. With kick starters the engine is started by human mechanical force, with electric starters it is started with a separate button (on the right hand grip). In addition, unlike cars, motorcycles are equipped with a kill switch (also on the right hand grip), with which the ignition of the engine can be interrupted at any time without having to reach for the ignition key.
In the meantime, the combination of the steering lock and the ignition lock has become established on newer motorcycles - similar to the case with cars . The previously widespread design with a separate handlebar lock is now rarely found.
safety
The steering lock as an anti-theft device is an approval-relevant component. Ignition locks without an anti-theft device (immobilizer) or the so-called kill switch are not components that are relevant for approval on motorcycles. An anti-theft device, even loose, is mandatory.
literature
- Rudolf Hüppen, Dieter Korp: Car electrics all types . Motorbuchverlag, Stuttgart, ISBN 3-87943-059-4
