Delphi injectors basic knowledge and the main failure mode |
First, the structure of Delphi injectors Second, Delphi injector assembly sequence: In Step 2, the orifice plate is installed as shown, on the body above the orifice Step 3, as shown armature assembly into the valve body Step 4, the valve spring pad and insert solenoid valve spring, and then the entire magnet assembly into the injector body Step 5, the first three steps as shown Couples assembled components and assembled the fourth step injector body attached to a piece of Step 6 Tighten the nipple tight cap, the entire injector assembly is completed
1, the closure phase: the solenoid is not energized, the armature assembly in a tapered seal under the action of the spring force of the oil passage is sealed tightly. A pass into the control chamber due to fuel and pass into the tank B is filled with the same fuel pressure (common rail), and acting on the needle end face of hydraulic force area much larger than the tip of the needle and the guide portion by hydrodynamic force area, and therefore the effect of force on the part of the downward movement, the needle valve that is seated tightly sealed when the nozzle holes, no fuel injection. Since the hydraulic servo injector injection timing change completely rely on each hydraulic control chamber to achieve, so it is powered from the solenoid to the presence of certain hydraulic injection start delay. The condition of all moving parts to wear guide surface will affect the hydraulic delay long and short, usually wear more powerful injection delay greater. Delay schematically shown below: Compared with similar Denso and Bosch hydraulic servo injector, Delphi injectors DFI2 hydraulic delay smaller. The reason DFI2 injector therefore no long stem hydraulic transmission time is relatively short. Popular terms, DFI2 corresponding rate than other similar injectors fast. Fourth, Delphi injector common failure mode 2, the armature cone seal wear 3, orifice plates wear 4, carbon or spray nozzle holes blocked |