How do piezo injectors work?
Piezo fuel injectors (CRI4), which use piezo crystals as part of a rapid actuator, are helping manufacturers to meet their Euro 6 target. These injectors work by passing electrical current through a stack of Piezo crystals, causing them to expand; as the crystal discharges the current it contracts to the original size.
How can you tell if you have piezo diesel injectors?
The majority of piezoelectric injectors may be recognised by the location of the leak off pipe, located at the side of the injector and not on the top as seen on the electromagnetic type. The operating fuel pressure within modern common rail systems may exceed 1,800 bar, or 26,100 psi.
What is the difference between piezo and solenoid injectors?
Piezo injectors are quieter and more precise than solenoid units, a benefit in a microsecond environment, but they are more expensive. The electronic engine management system controls the precise opening and closing of the fuel-flow valve in each injector.
Does Cummins use piezo injectors?
Piezo injectors are also used in Ford’s 6.7L Power Stroke and GM’s ’11 to present LML Duramax, and will be utilized in the Nissan Titan–destined 5.0L V-8 from Cummins.
Can piezo injectors be repaired?
It is very specialised work, and can’t be undertaken by every repair shop. The injector is totally stripped down, cleaned ultrasonically, and reassembled with new parts fitted if necessary.
What is the activation voltage for piezo injectors?
WARNING HIGH VOLTAGE: Piezo injectors normally operate at voltages up to 200 volts. Extreme care should be taken to protect against shock. Do not touch any of the injector terminals while the engine is running.
Are Cummins injectors oil fired?
You Can’t Run Them Out of Oil Because the injection system relies on engine oil to activate the fuel injectors, the injectors will fail to fire once oil supply drops below a specific threshold.
Can you clean piezo injectors?
Ultrasonic cleaning – the injectors undergo a 3 stage ultrasonic cleaning process, the first is to remove all exterior dirt / paint, the second is the injectors are ultrasonically cleaned in a heated bath and the last process involves a final session in another ultrasonic bath.
How does a piezo actuator work?
A piezoelectric actuator converts an electrical signal into a precisely controlled physical displacement (stroke). If displacement is prevented, a useable force (blocking force) will develop.
Can bad injectors cause Blowby?
Registered. Bad injectors dont cause blowby.
How does the piezo valve in a rail injector work?
Pumped fuel enters the injector via the fuel feed collar and excess can return to the tank via the fuel return collar. The camshaft follower presses the plunger at the top to pressurise the fuel in the injector. The piezo valve controls the release of this high pressure fuel through the injector nozzle into the combustion chamber.
How many injectors does a common rail fuel system use?
The key is the innovative injection system: it works with rapid switch, compact piezo-inline injectors. Some advanced common rail fuel systems perform as many as five injections per stroke. Fig. 1 shows a typical common rail piezo injector.
How are piezoelectric crystals used in diesel injectors?
Utilizing these noted characteristics of piezoelectric crystals, piezo crystals thus found its use as a critical component in the Piezoelectric injector. With their ability to expand rapidly when in contact with an electrical charge, Piezoelectric crystals serve as efficient actuators in diesel fuel injectors.
How does piezo fuel return to the tank?
Pressurized fuel is also sent to the top of this needle, the force from which keeps the needle closed. When energized, the Piezo crystal will open a valve above the needle. This allows the pressurized fuel at the top of the needle to return to the tank through the return line.
