Sleeve-Metering Rotary Distributor Pumps Chapter 24

1. Sleeve-Metering Rotary Distributor Pumps Chapter 24 DSL 131

2. OBJECTIVES • Identify the main components of a sleeve-metering, distributor injection pump. • Describe the operating principles of a sleeve-metering, distributor injection pump. • Explain how fuel is routed, pumped, and metered from the fuel pump to the injector during a sleeve-metering, distributor injection pump cycle. • Outline the circuits in a sleeve-metering, distributor injection pump. • Describe the operating principles of a Bosch VE rotary injection pump. • Identify Bosch VE electronically-controlled rotary distributor pump systems. • Trace fuel flow routing from tank to injector on electronically-controlled, rotary distributor pump fueled diesel engines. • Identify Bosch Electronic Diesel Control (EDC) system components used to manage rotary distributor pump injection systems.

3. INTRODUCTION • In the days before electronic engine management systems , a significant disadvantage of port-helix metering injection pumps was up-front cost due to its requirement for close tolerance manufacture and a pump/metering element for each cylinder on the engine. • In the quest for lower-cost alternatives, manufacturers looked at rotary distributor pumps which used a single pump element in combination with a distributor head to fuel all the engine cylinders.

4. INTRODUCTION (Cont.) • Among the advantages offered by rotary distributor injection pumps are: • Lower up-front cost • Simple disassembly and reassembly (for purposes of cleaning) not requiring costly calibration equipment • Hard value phasing of injection pulse not influenced by wear • Balanced cylinder fueling

5. SLEEVE-METERING, SINGLEPLUNGER DISTRIBUTOR PUMPS • Bosch hydromechanical, sleeve-metering distributor injection pumps use a single plunger pumping element. • In describing this technology, the popular VE pump is used as our primary reference.

6. SLEEVE-METERING, SINGLEPLUNGER DISTRIBUTOR PUMPS • A VE pump has four primary circuits: • Fuel-supply pump • High-pressure pump • Governor • Variable timing

7. SUBASSEMBLIES • All movement through the fuel subsystem is the responsibility of a vane-type transfer pump integral with the VE pump assembly.

8. VE Distributor Pump Fuel System Layout

9. SUBASSEMBLIES (Cont.) • The VE distributor pump housing contains the following subcircuits: • High-pressure (injection) pump with distributor • Mechanical (flyweight) governor • Hydraulic timing device • Vane-type fuel supply pump • Shutoff device • Engine-specific add-on modules

10. Location of Pump Subcircuits

11. Interaction of Fuel Supply Pump, Pressure Control Valve, and Overflow Restriction Valve

12. High-Pressure Pump Components

13. Exploded View of theHigh-Pressure Pump Components

14. Plunger Stroke and Delivery Phases

15. Distributor Head with Pump Chamber

16. Constant-Pressure Delivery Valve

17. VE Governor Assembly

18. VE Governor Assembly

19. Timing Device Operating Principle

20. VE Add-On Modules

21. Pintle-Type Nozzle Equipped with anNVMS

22. NVMS Tracking Waves:Unconditioned (#1)Conditioned (#2)

23. Schematic of How Output Algorithms Are Mappedin a Typical Bosch EDC-Managed VE Pump

24. Partial Authority VE Distributor InjectionPump Adapted for Electronic Control

25. SUMMARY • The main components of a Bosch sleeve-metering, distributor injection pump are: • Vane-type transfer pump • Cam plate • Single plunger–actuated pump chamber • Distributor head • Delivery valves • Control sleeve • Governor assembly • Advance mechanism

26. SUMMARY (Cont.) • A sleeve-metering, distributor injection pump uses axial movement of a sleeve on the pumping plunger to alter the effective pumping stroke. • The plunger both rotates and reciprocates to pressurize and distribute fuel to outlets in the distributor head.

27. SUMMARY (Cont.) • Movement of fuel through the fuel subsystem in a sleeve-metering, distributor injection pump is the responsibility of a vane-type transfer pump. • Actual pump plunger stroke is defined by the actuating cam geometry. • The position of the metering or control sleeve determines the actual fuel pumped.

28. SUMMARY (Cont.) • EDC-managed VE injection pumps use hydraulic injectors with pintle nozzles. • Sometimes these pintle nozzles are equipped with nozzle valve motion sensors (NVMSs).

29. SUMMARY (Cont.) • An NVMS consists of a coil and nozzle valve-actuated pressure pin. • Movement of the nozzle valve-actuated pressure pin through the coil winding changes the coil reluctance, inducing a signal voltage proportional to the valve’s speed of movement.

30. SUMMARY (Cont.) • The NVMS enables the ECU to determine the precise moment of start of injection, which helps build the algorithms required for injection timing and EGR management. • The key actuator circuit components in a partial authority, VE pump are the control sleeve solenoid (controls effective pump stroke/fuel quantity) and the start-of-injection solenoid valve (controls timing).

31. Any Questions ? • Thank You !