VP44 Service Manual
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Transcript of VP44 Service Manual
Pub. No. EE14E-11130
SERVICE MANUAL CONSTRUCTION& OPERATION
VP44
FOREWORDThis service manual describes the constructionand operation of the VP 44 (Radial plungerdistributor type fuel injection pump).This manual is intended for use by vehiclemaintenance technicians or persons with anadequate knowledge of injection pumps.
The contents of the manual, includingillustrations, drawings and specifications werethe latest available at the time of printing.The right is reserved to make changes inspecifications and procedures at any timewithout notice.
Tokyo, Japan
CONTENTS
PageCOMPONENT OUTLINE ........................ 1
1. OUTLINE ................................................ 1
2. FEATURES............................................. 2
3. SPECIFICATIONS .................................. 3
4. FUEL SYSTEM ....................................... 4
5. SYSTEM CONTROL DIAGRAM ............. 7
6. CONTROL UNIT SYSTEM
CONTROL DIAGRAMS ......................... 8
CONSTRUCTION ................................... 9
1. EXTERNAL VIEW................................... 9
2. CROSS-SECTIONAL VIEW ................. 10
3. EXPLODED VIEW ................................ 11
4. CONSTRUCTION ................................. 12
OPERATION ........................................ 21
1. LOW PRESSURE FUEL CIRCUIT ....... 21
2. HIGH PRESSURE FUEL CIRCUIT ...... 23
3. TIMING CONTROL ............................... 29
4. ANGULAR ENCODER ......................... 34
5. PUMP CONTROL UNIT........................ 35
- 1 -
COMPONENT OUTLINE
With radial plunger distributor type fuel injectionpumps, the fuel is pressurized by a radialplunger high pressure pump (with 2 or 3cylinders, depending on the number of enginecylinders) positioned axially to the driveshaft.Fuel injection quantity and timing are preciselycontrolled by two electronic control units.A high pressure solenoid valve and a TCV (atimer) are controlled by a pump control unitinstalled at the top of the pump. This controlunit works together with a second control unit,ie, the engine control unit (which detects suchvehicle information as engine speed andaccelerator pedal position), in a dual control unitsystem to ensure high reliability.
1. OUTLINE
Instead of utilizing the previous face cam, theradial plunger distributor type fuel injection pumputilizes a cam ring to enable fuel injection at highpressures, making it suitable for small, highspeed direct injection diesel engines.This pump was developed to provide the mostsuitable fuel injection quantity and injectiontiming to satisfy the demand for engine reliability,driveability, low smoke, low noise, high outputand cleaner exhaust emissions.
Pump control unit
Radial plunger high pressure pump
High pressure solenoid valve
Driveshaft
P-VP4C-001
TCV
- 2 -
COMPONENT OUTLINE
2. FEATURES[1] High pressure injectionThe radial plunger distributor type injectionpump can generate pressure of 100 MPa{approx 1,000 kgf/cm2} demanded by the small,fuel efficient, high pressure, high speed directinjection diesel engines.[2] High pressure atomization of fuel
injected from the nozzleThrough high pressure injection of fuel, the fuelinjection from the nozzle is atomized at highpressure with a high penetrating force (the fueldroplets penetrate further) and with greaterdispersion and distribution (mixing with air isimproved) so that combustion is improved. Thiscontributes to cleaner emissions.[3] Optimum fuel injection systemHigh speed control of fuel injection quantity andfuel injection timing suitable for the engine isperformed by the control unit, enabling lowerfuel cost and high output.[4] Improved enduranceThe components used in the pump are veryresistant to high pressure, ensuring improvedendurance.[5] Improved engine matchingAs fuel injection to the engine can be controlledfor each cylinder, matching to the engine isimproved.[6] Improved reliabilityAs a dual control unit system with both an enginecontrol unit and a pump control unit is used, thecontrol system is extremely reliable.
[7] Improved power performanceAs the optimum fuel injection quantitycorresponding to accelerator position iscontrolled by the control unit, increased torquein low accelerator pedal positions is possible,enabling improved power performance.[8] Decreased smoke at accelerationWhen fuel injection is increased to increaseengine power at acceleration, smoke is usuallygenerated by the excess fuel. The VP44 fuelinjection pump, however, accurately controlsfuel injection quantity even in this range toprevent the generation of smoke withoutadversely affecting acceleration.[9] Additional devices are unnecessarySuch addit ional devices as the boostcompensator and the aneroid compensator areunnecessary as compensation is made by thecontrol unit based on signals from each sensor.This results in less ‘clutter’ around the injectionpump.[10] Self diagnosis functionThe system includes a self diagnosis functionwhich displays error codes to facilitate thediagnosis of malfunctions.
- 3 -
COMPONENT OUTLINE
3. SPECIFICATIONSItem
Injection pump typeApplicable vehicles
Applicable number of engine cylindersDirection of rotationDrive methodInjection performance
Maximum pump pressurePlunger diameter x number
Maximum liftMaximum plunger speedMaximum allowable drive torque
SystemMinimum drive voltageMaximum high pressure solenoidvalve currentControl unit type
Battery specificationStandard performance
Standard control method
Timing feed backCompensation for variation betweenpump fuel injection quantitiesTimer advance angle range
Pump sizeWeight
SpecificationsVP44Passenger vehicles, recreational vehicles, small andmedium sized trucks (less than 1 / cylinder)4 cylinders, 6 cylindersClockwise / counter clockwiseToothed belt, gear, chain
100 MPa {approx 1000 kgf/cm2}4 cylinder: φ6.5 mm x 2, φ7 mm x 2, φ7.5 mm x 26 cylinder: φ7 mm x 3, φ7.5 mm x 33.5 mm1.9 m/second: 1000 r/min200 N.m {20.4 kgf.m}: 3 holed flange260 N.m {26.5 kgf.m: 4 holed flange(Maximum drive torque necessary under actual usageconditions: 150 N.m {15.3 kgf.m} limit)
6V≦20 A
Engine control unit, pump control unit(dual control unit system)12V specification, 24V specification
Fuel injection quantity control: high pressure solenoidvalve, time controlInjection timing control: TCV duty solenoid system,hydraulic timerCam position feed backPump EPROM, multi point compensation
Maximum advance angle: 15゜Identical to COVEC-FApprox 8.0 kg
- 4 -
COMPONENT OUTLINE
(1) Fuel piping systemCentering around the radial plunger distributortype fuel injection pump, the fuel piping systemconsists of a fuel tank, a feed pump, a fuel filter,nozzle holder assemblies and the pipingconnecting these components.(2) Fuel intakeThe fuel in the fuel tank is supplied to theinjection pump through the fuel inlet by the feedpumps in the fuel tank and the injection pump,after first passing through the fuel filter.The fuel filter is installed to filter the fuel, andalso has a sedimenter in the bottom to separateany water from the fuel.(3) Regulating fuel feed pressure and
delivery pressureThe fuel taken in at the fuel intake port ispressurized by the feed pump inside theinjection pump, and is then supplied to theplunger chamber through the high pressuresolenoid valve’s valve needle, which controlsthe direction of fuel flow.
4. FUEL SYSTEM[1] Fuel system schematic
Fuel tank
Feed pump
Fuel filter
Radial plunger distributortype fuel injection pump
Low pressure pipe
Nozzle holder assembly
Engine controlunit
P-VP4C-002
High pressure pipe
Pump control unit Overflow valve
At this time, the fuel pressure is greatest inproportion to pump rotational speed. When itexceeds a specified pressure, excess fuel isreturned to the intake side through the regulatingvalve.(4) Fuel pressurizationThe fuel delivered to the plunger chamber ispressurized by the radial plungers.(5) Determining the optimum fuel injection
quantity and fuel injection timingThe optimum quantity of high pressure fuel ispressure fed to the nozzle holder assembly atthe optimum timing by the high pressuresolenoid valve and the TCV (timer) controlledby the pump control unit.
- 5 -
COMPONENT OUTLINE
[2] Injection pump fuel intake system
[3] Injection pump fuel pressure feed system
Engine control unit
Fuel intake
Pump control unit
Feed pump
Regulating valve
Overflow valve
High pressuresolenoid valve
Constantpressurevalve
Radial plungerhigh pressure pump
Distr ibutor head
P-VP4C-003
P-VP4C-004
- 6 -
COMPONENT OUTLINE
[4] Fuel pressurization control
P-VP4C-005
Accumulatordiaphragm
Diaphragmchamber
Overflow valve
Feed pump
Regulating valve
TCV
To feed pump intake
Servo valve
Hydraulicstopper
Timer pistondrive fuelcharge
Timer piston
High pressuresolenoid valve
Constantpressurevalve
Radial plunger
Valve needle
High pressurepassage
Timer pistondrive fuel return
- 7 -
COMPONENT OUTLINE
5. SYSTEM CONTROL DIAGRAM
P-VP4C-006
Engine speed(crank shaft)
Accelerator pedal
Idle switch
Boost pressure
Air flow volume
Air temperature
Cooling watertemperature
Vehicle speed
Cruise controloperation panel
Brake
Clutch
Air conditioner
Beginning ofinjection
+12V (24V)
Engine control unit
Power supply
Atmospheric pressure sensorSignal inputSignal evaluation
Signal processing・ Fuel injection quantity・ Beginning of pressure feed・ EGR・ Boost pressure・ Vehicle speed・ Engine load・ Monitor・ Minimum function
maintenance・ Calibration
Power outputSignal output
InterfaceDiagnosis
Radial plunger distr ibutor typeinjection pump
Pump control unit
+12V(24V)
CAN
DZG
MAB
LGS
EPC
EPC
Option
EGR valve
Turbo charger
A/C compressor
Diagnostic lamp
Diagnosticrequirement
Service tester
CAN
AutomatictransmissionEngine control unit
CAN: Control area networkDZG: Crankshaft speedMAB: Solenoid valve switch OFFLGS: Low idle signal
- 8 -
COMPONENT OUTLINE
6. CONTROL UNIT SYSTEM CONTROL DIAGRAMS[1] Block diagram
[2] Circuit diagram
Engine control unit(ECU)
Pumpcontrol unit(PCU)
Fuel injectionpump(mechanicalsection)
Injection timing
Injection quantity
Response signal
Additionalsignals
Engine speed
Accelerator pedal
Air temperature
Boost pressure
Air flow volume
Others
Sensors
Additionaloperations
To high pressure solenoid valve
Timer controldevice
Cam ring rotational angle
High pressuresolenoid valve
To timer control device
Self diagnosis / interface / signal
Engine speed(crank)
Accelerator pedalIdle switch
Engine control unit Pump control unit
Pump speed
Injection quantity
Injection timing
High pressuresolenoid valve
CAN
MAB
DZG
High pressuresolenoid valve
P-VP4C-007
CAN: Control area networkMAB: Solenoid valve switch OFFDZG: Crankshaft speed
Fuel temperature