FUEL SYSTEM


  1. CONSTRUCTION


    1. The supply pump (injection or supply pump assembly) consists of an inner cam (eccentric camshaft), an outer cam (polygon ring), 3 plungers, a metering unit and a gear pump. Each plunger is placed outside of the outer cam.

    2. The gear pump pumps fuel to the 3 plungers.

    3. A metering unit controls the volume of fuel drawn into the plungers.

    4. The inner cam drives the outer cam.

    5. The outer cam drives the 3 plungers.

    6. The plungers pressurize the fuel.

      A00XROOC01
      *1 Metering Unit *2 Plunger
      *3 Inner Cam (Eccentric Camshaft) *4 Outer Cam
      *5 Gear Pump - -

  2. OPERATION


    1. Due to the rotation of the inner cam (eccentric camshaft), the outer cam pushes plunger "A" upward as illustrated below. The force of the spring pulls plunger "B". As a result, plunger "B" draws fuel in, and plunger "A" pumps fuel at the same time.

      A00XRN3C02
      *1 Metering Unit *2 Plunger A
      *3 Plunger B *4 Plunger C
      *a Suction *b to Common-rail
      *c Pumping Finish *d Pumping Start