Mercedes S-Class W-220
since 1998 release
Repair and operation of the car
+ Mercedes-Benz cars of the class S (W220)
+ Operation manual
+ Routine maintenance
+ Cooling system and heating
- Power supply system and release
- Power supply system and fuel injection
Dropping pressure in fuel system of the petrol engine
Management of distribution of power - the description and the principle of the organization of function of shutdown of cylinders
Supercharger of air
Check and adjustment of speed of the single course / moment of ignition/concentration WITH
+ System of injection of fuel of the diesel engine. Turbocompressor
+ Systems of release and decrease in toxicity of the fulfilled gases
+ Engine electric equipment
+ Automatic transmission
+ Power shafts
+ Brake system
+ Suspension bracket and steering
+ Onboard electric equipment
+ Schemes of electric equipment
Management of distribution of power - the description and the principle of the organization of function of shutdown of cylindersShutdown of cylinders for decrease in fuel consumption
Drive of shutdown of cylinders
Valves of cylinders 2 and 3 of the right row are switched-off, it is equal as cylinders 5 and 8 of the left number under certain conditions of functioning of the engine.
Design/principle of functioning
For shutdown of cylinders 2 and 3 (the right number of cylinders) and 5 and 8 (the left row) their inlet and final valves stop functioning. At the switched-off cylinders their valves remain constantly closed, the injection in them of fuel and giving of VV of tension of system of ignition in parallel stops.
Function of shutdown is organized in the module of management of the engine (ECM):
- Activation of the valve of shutdown for cylinders of the right row (Y80).
- Activation of the valve of shutdown for cylinders of the left row (Y81).
- Activation of the final lamellar valve (Y93).
- Signal of the sensor of pressure of oil of system of shutdown of cylinders (B40/2).
- A signal of the sensor of pressure (B28), absolute pressure in the inlet pipeline.
- Identification of refusals of shutdown.
The used entrance signals in ECM:
- From CKP sensors and turns of the engine.
- From the sensor of provision of a butterfly valve (TPS).
- Transfer inclusion signal.
- From the oil temperature sensor.
The applied ECM (ME-SFI) parameters adapt to function of shutdown of cylinders. For example:
- Shutdown of supply of fuel and supply voltage in certain cylinders with the subsequent reorganization of phases of gas distribution and an advancing of ignition under new conditions (cylinders are switched-off).
- Activation of the actuation mechanism of a butterfly valve.
- Extrapolation of working parameters under further change of conditions (cylinders are switched-off/are switched on).
- Adaptation of composition of mix under the current changes in air supply and pressure.
- Correction of an algorithm of diagnostics of STAR.
Function of shutdown of cylinders is deactivated
Both sections of the switched yoke are blocked among themselves by means of a mobile connecting pin. The spring wrings out a pin in the provision of blocking.
Function of shutdown of cylinders is activated
Valves of shutdown of cylinders of the right and left ranks (Y80 and Y81) are activated at the command of ECM and open. Oil under pressure moves under press a finger through axes of yokes that it leads to push-up of connecting pins back. Sections of yokes receive separate degrees of freedom and gain ability to move freely from each other. Inlet and final valves stop functioning.
The Rasstykovanny valvate lever leans on a cam heel that guarantees hit of the sliding blocking finger in a nest of a roller cam for cancellation of function of shutdown of cylinders.
Working moments of the procedure of shutdown of cylinders
In view of design features, shutdown of cylinders can be realized only in certain provisions of the engine:
- Valves have to be closed. Operation becomes possible only at the unloaded yokes.
- Upon completion of a running cycle final valves are always switched-off the first, inlet - the last. At the same time gas under pressure gets to the switched-off cylinder. Pressure interferes with an oil conclusion from a case. The lambda management remains disconnected at further turning on of cylinders and the fulfilled gases are produced.
- At first cylinders 2 and 3 of the right row then 8 and 5 left are switched-off (as transfer).
Condition of activation of function of shutdown of cylinders
- The shutdown period (about 20 seconds) expires after start of the engine.
- Temperature of cooling liquid of the engine is higher than +20 °C.
- Engine turns at the normal worker of temperature make:
" 925 ÷ 1700 a minute by the included 3rd transfer.
" 925 ÷ 1700 a minute by the included 4th transfer.
" 925 ÷ 3500 in a minute by the included 5th transfer.
- AT mode: 3, 4 or D.
- The angle of opening of a butterfly valve does not exceed the threshold value determined by requests of the engine.
- Pressure of oil exceeds value of 2.5 atm.
- Temperature of motive oil is in limits of the range of 20 ÷ 130 °C.
- Temperature of the soaked-up air makes about-40 ÷ of 100 °C.
- Height of the place does not exceed value of 2500 m above sea level.
- The output tension of the battery makes not less than 10.5 Century.
- Shutdown of cylinders happens for STAR diagnostics coding option.
- The controller of a control system of draft (ASR) is not activated.
Condition of deactivation of function of shutdown of cylinders
- Admissions of ignition, harmful to the 3-functional catalytic converter (TWC), come to light.
- Violation of operation of function of shutdown of cylinders is revealed.
- Emergency operation of electronic control is activated by the accelerator pedal
- There was a refusal of delivery of a signal of the sensor of temperature of oil.
- There was a refusal of delivery of a signal of the sensor of pressure of oil.
- Upon the demand of the device of diagnostics of a functional chain.
- Violation of stability of turns, excessive for conditions of the disconnected condition of cylinders, takes place.
- The most admissible time of continuous functioning (about 25 seconds) is exceeded.
Function of shutdown of cylinders will be activated about 20 seconds again later.
Threshold of activation of function of shutdown of cylinders
The threshold of activation defines conditions of shutdown and inclusion of function of shutdown of cylinders at average turns of a bent shaft and moderate load of the engine and depends on correctness of programming of parameters of diagnostics of STAR. The following adjustments on a program correcting are allowed:
- The threshold gets out of basic installations of parameters of return of the engine
- Restriction for activation at turns is introduced lower than 1500 a minute.
- Restriction on current state of parameters of return of the engine is introduced.
- Function of shutdown is deactivated.
Activation of the actuation mechanism of a butterfly valve
At activation of function 4 cylinders of the engine are switched-off. At the same time the torque remains so constant as far as it is possible. The butterfly valve opens again, depending on loading and turns of the engine. At shutdown of cylinders the reverse joins and the butterfly valve is respectively closed.
The butterfly valve is quickly activated before the moments of inclusion and shutdown of function of shutdown of cylinders.
When switching between two modes of functioning of the engine the same torque for the purpose of an exception of a noticeable difference in the power developed by the engine and achievements of smoothness of switching whenever possible has to develop.
Activation of the final gate
At the activated function of shutdown of cylinders the electromagnetic valve switch of the final gate works at the command of ECM (ME-SFI) at engine turns till 2500 a minute. On a diaphragm of the actuation mechanism depression moves and the gate partially blocks the section of an exhaust pipe that allows to reduce the level of a noise background.
Activation of valves of shutdown of cylinders
Valves of shutdown of cylinders of the right and left ranks (Y80 and Y81) are activated software the pulse signal of tension given directly by the module of management of the engine (ME-SFI).
At the activated function of shutdown of cylinders switching speed approximately within about 0.5 seconds reaches 95% for the purpose of increase in starting current and increase in speed of reaction. Windings of the coil are protected from thermal overloads by introduction of a temporary restriction.
The additional measures applied on the power unit at the switched-off cylinders
- The oil pump of the increased productivity is selected (as on the engine 120).
- On the belt drive the vibration damper is established.
- For the purpose of decrease in a noise background the rotation converter with a turbine damper of the twisting efforts is used.