crank sensor is an electronic device used in internal combustion engines, both gasoline and diesel, to monitor the position or speed of the crankshaft rotation. This information is used by the engine management system to control fuel injections or ignition timing systems and other engine parameters. Before electronic crank sensors are available, the distributor must be manually adjusted to the time sign on the gasoline engine.
The crank sensor can be used in combination with the same camshaft position sensor to monitor the connection between the piston and the valves in the engine, which is essential in engines with variable valve timings. This method is also used to "synchronize" the engine four steps after starting, allowing the management system to know when to inject fuel. It is also commonly used as a primary source for measuring engine speed in revolutions per minute.
Common installation locations include main crank pulley, flywheel, camshaft or on the crankshaft itself. This sensor is the second most important sensor in modern engines after the camshaft position sensor. When it fails, it is possible the machine will not start, or cut off while walking.
Video Crankshaft position sensor
Jenis sensor
There are three main types of sensors that are commonly used. Hall Effect Sensor, Optical sensor or Inductive sensor. Hall effect sensors have advantages over inductive sensors because they can detect static magnetic fields (unchanged).
Some machines, such as the GM Premium V family, use a crank position sensor that reads an integral divider ring with harmonic balancer. This is a much more accurate method for determining the position of the crankshaft, and allows the computer to determine in some degree the exact position of the crankshaft (and thus all the connected components) at any given time.
Maps Crankshaft position sensor
Function
The functional purpose for the crankshaft position sensor is to determine the position and/or rotation speed (RPM) of the crank. Engine Control Units use information transmitted by sensors to control parameters such as ignition timing and fuel inject time. Inside the diesel, the sensor will control the fuel injection. The sensor output may also be related to other sensor data including cam position to obtain the current combustion cycle, it is very important to start the four-step engine.
Sometimes, the sensor can become burned or obsolete - or die of old age with high mileage. One possible cause of crankshaft position sensor failure is extreme heat exposure. Another is the vibration that causes the wire to crack or corrosion on the connector pin harness. Many modern crankshaft sensors are sealed units and therefore will not be damaged by water or other liquids. When an error occurs, it stops sending signals containing vital data for the ignition key and other parts of the system.
Bad crank position sensors can exacerbate the workings of idle engines, or acceleration behavior. If the machine is turned on with a bad or damaged sensor, it can cause a shoot, motor or boomerang vibration. Acceleration may hesitate, and trembling is not normal when a silent machine may occur. In the worst case the car may not start.
The first sign of a crankshaft sensor failure, typically, is the machine's refusal to start during heat but will start again after the engine has cooled down.
One detail of some designs is the three-wire inductive "three wire" sensor in which the third wire is actually just a co-axial shield around two main sensor cables to prevent them from taking wild electric pulses from elsewhere in the engine bay.
Bicycle
Another type of crank sensor is used on the bike to monitor the position of the crankset, usually for the rhythm reading of a cyclecuter. These are usually reed switches mounted on a bicycle frame with a magnet attached to one of the crankset's pedal arms.
Note
GMR technology (giant magnetoresistance) is also used for Crank, Cam rotor sensing purpose. Mitsubishi is the first to use this technology in automotive application purposes.
External links
- Crankshaft & amp; Camshaft Position Sensor
- Crank Position Sensor
Source of the article : Wikipedia
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