Subaru Forester

1997-2005 of release

Repair and car operation



Subaru Forester
+ Cars Subaru Forester
+ The maintenance instruction
+ Routine maintenance
+ The engine
+ Systems of cooling, heating
- The power supply system and release
   Specifications
   System of release of the fulfilled gases - the general information
   Measurement of pressure of fuel
   Pressure dump in the power supply system
   Principle of action and check of serviceability of functioning of the fuel pump
   Service of the fuel filter
   Check of a condition and replacement of fuel lines and them штуцерных connections
   Service перекидного the valve
   Removal and installation of the case of a throttle
   Injectors of injection of fuel - the general information and service
   Regulator of pressure of fuel - the general data
   Cleaning and repair of a fuel tank - the general data
   Removal and installation of the gauge of measurement of weight of air (MAF)
   Check of serviceability of functioning of system of electronic injection
   Turbo-supercharging system - the general information
   Service of system of a turbo-supercharging
   Release system - the general information
+ Engine electric equipment
+ Control systems of the engine
+ Gear change box
+ Coupling, трансмиссионная a line
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
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Turbo-supercharging system - the general information

The general information and functioning principle

The system consists from турбокомпрессора with water cooling, an intermediate cooler (Intercooler) and control systems of pressurisation (MPFI Turbo).

The scheme of functioning of system of a turbo-supercharging

1  — the  Gauge of speed of movement of the car (VSS)
2  — the  Gauge of position throttle заслонки (TPS)
3  — the  Gauge of temperature of a cooling liquid of the engine (ECT)
4  — the  Gauge of position of a cranked shaft (CKP)
5  — the  Gauge of the expense of air
6  — the  Valve перепускания air
7  — the  Electromagnetic valve of management of pressure dump
8  — a  drive Diaphragm перепускного the valve
9  —  Perepusknoj the valve of dump of pressure
10  —  Turbokompressor
11  — the  Intermediate cooler (Intercooler)
12  — the  Direction of giving of air at fast closing throttle заслонки

13  —  Water hoses
14  —  Throttle заслонка
15  — the  Valve of switching of pressure of air
16  — the  Pump of an intermediate cooler
17  — the  Electromotor of a drive of the fan of system of cooling
18  — the  Fan of system of cooling
19  — the  Radiator of an intermediate cooler
20  — the  Radiator of system of cooling
21  — the  Gauge of pressure of air
22  — the  management Block (MPFI Turbo)


The control system allows to force the engine on capacity that in an essential measure raises efficiency of its return and, as consequence, improves manoeuvrability of the car in all working ranges. In a control system function of indemnification of change of barometric pressure at car operation in high-mountainous district is provided.

Air, having passed an air cleaner, gets in турбокомпрессор, after compression in which, it is cooled in the heat exchanger of an intermediate cooler (Intercooler) then moves in the case of a throttle and further, - in the inlet pipeline and engine cylinders.

For демпфирования fast change of pressure at sharp closing throttle заслонки bypassing it it is provided special перепускной the channel. At sharp increase of depth of depression at closing заслонки air on the given channel arrives on a compressor input. Application to such system allows to lower appreciably level of a noise background during braking by the engine.

The control system of pressurisation (MPFI Turbo) consists of the gauge of pressure of air, the block of the management, the operating electromagnetic valve, a drive diaphragm перепускного the valve and actually the valve of dump of the pressure providing перепускание of gases by the turbine. The gauge of pressure of air supplies the block of management with the information on pressure in the inlet pipeline.

turbocharger

Design features

Design турбокомпрессора

1  —  oil Plums
2  —  air Input
3  —  Pressure of pressurisation
4  —  oil Giving
5  — the  Fulfilled gases
6  —  Compressed air
7  —  Giving of a cooling liquid

 


The compressor is equipped by own water shirt and перепускным the valve of dump of pressure. The turbine is made of a heat-resistant steel, the compressor case, - from an aluminium alloy. The turbine shaft is kept in bearings of floating type.

Adjustment of pressure of pressurisation

Appointment перепускного the valve of dump of pressure

With increase in frequency of rotation of a cranked shaft (at similar positions throttle заслонки) the expense of the fulfilled gases increases that, in turn, leads to growth of turns of a shaft of the turbine (approximately with 20 000 to 150 000 in a minute) and, accordingly, - pressure of pressurisation. Growth of pressure of pressurisation can lead to detonation combustion of an air-fuel mix (diesel engine-effect) and, as consequence, - to increase of thermal loading on the bottoms of pistons that is fraught with damage of internal components of the engine. For the purpose of liquidation of similar effect the compressor is equipped by the special valve of dump of the pressure providing перепускание of gases bypassing the turbine.

The scheme of functioning of the valve of dump of pressure


1  —  Turbokompressor
2  — the  Valve of dump of pressure
3  — a  drive Diaphragm перепускного the valve

 


The perepusknoj valve stays in the closed position until pressure of pressurisation remains below admissible value. Thus all stream of the fulfilled gases is passed through the turbine.

As soon as pressure upon an operating diaphragm passes for limits of admissible value, перепускной the valve opens also a part of the fulfilled gases is dumped bypassing the turbine directly in release system. Thus a difference of pressure Р1 - Р2 (where Р1 - atmospheric pressure; Р2 - pressure in the inlet pipeline) is supported by a constant.


The concept of management of pressure of pressurisation


At car operation at the big height above sea level where already appreciable fall of atmospheric pressure concerning normal takes place, the control system of pressurisation provides support of the maximum absolute value of pressure of pressurisation.


Greasing турбокомпрессора

turbocharger receives oil from system of greasing of the engine. As soon as frequency of rotation of a shaft of the turbine reaches several thousand turns a minute, shaft bearings "emerge" on the oil wedge formed as with external, and from the inside подшипниковой of assemblage. Except greasing of bearings oil provides also additional heat removal from турбокомпрессора.

The greasing scheme турбокомпрессора


1  — a  turbine Wheel
2  — the  Fulfilled gases
3  —  Oil
4  — the  Snail of the turbine
5  — a  compressor Wheel
6  — the  Snail of the compressor
7  —  Air

 


Cooling турбокомпрессора

About the purpose of increase of service life and reliability of functioning турбокомпрессора in its case the water shirt of cooling is provided. The cooling liquid arrives on connecting hoses from a water shirt of the engine. After selection of heat from турбокомпрессора the working liquid goes to a broad tank of system of cooling.

System of intermediate cooling of air

The scheme of functioning of system of an intermediate cooler of system of a turbo-supercharging

1  — the  Radiator of an intermediate cooler
2  — the  Radiator of system of cooling
3  —  the Input of a cooling liquid
4  — the  Fan
5  — the  Air outlet
6  — the  Electromotor of a drive of the fan
7  — the  Exit of a cooling liquid
8  — the  cooler Pump

9  — the  Cooler
10  —  air Input
11  — the  Electromotor of a drive of the pump
12  — the  Gauge of speed of movement of the car (VSS)
13  — the  Gauge of temperature of a cooling liquid (ECT)
14  — the  Gauge of position throttle заслонки (TPS)
15  — the  management Block


Intermediate cooling of air after its exit from the compressor raises efficiency of functioning of system of a turbo-supercharging, reduces probability of occurrence of a detonation of a mix and promotes reduction of the expense of fuel.

The scheme of connection of the heat exchanger of an intermediate cooler of system of a turbo-supercharging

1  — the  Air inlet
2  — the  Air cleaner
3  —  Turbokompressor
4  — the  Cooler (Intercooler)
5  — the  Engine
6  — a  cooler Radiator
7  — the  cooler Pump

 


The intermediate cooler (Intercooler) represents the water-air heat exchanger with low hydraulic resistance and high cooling ability.

Design of the heat exchanger of an intermediate cooler (Intercooler) turbo-supercharging systems

1  — the  Air outlet
2  —  air Input
3  —  the Input of a cooling liquid
4  — the  Exit of a cooling liquid

 


The heat exchanger of an intermediate cooler consisting of five separate blocks, is executed from an aluminium alloy and provides tap of surplus of heat from the air stream which temperature rises as a result адиабатического compression in the compressor.

The scheme of connection of a radiator of an intermediate cooler of system of a turbo-supercharging

1  — a  cooler Radiator
2  — the  throttle Case
3  — the  Cover of system of cooling
4  —  Interkuler
5  — the  cooler Pump

 


The radiator of an intermediate cooler is made from оребренных aluminium pipes. The left tank of a radiator is divided on two parts that allows to provide more effectively heat removal from a cooling liquid. For removal from a path of air stoppers the special ventilating stopper is provided.

Design of the pump of an intermediate cooler

1 — the  Winding
2  —  Krylchatka
3  — a  liquid Input

 


The drive крыльчатки the pump of an intermediate cooler is carried out from the individual electromotor.

Which capacity makes an order of 28 Vt at opening throttle заслонки less than 80 % and 50 Vt at большем opening заслонки. The given scheme is realised for the purpose of economy of expenses of capacity.

The valve перепускания air in pressurisation system

As already it was told above, at sharp closing throttle заслонки in system of an admission of air there can be a low-frequency rumble. For the purpose of minimisation of a sound background at braking by the engine in a path of system of a turbo-supercharging it is included special перепускной the valve. The valve works under the influence of the depression arising for throttle заслонкой at its sharp closing, as a result air from the throttle chamber перенаправляется on a compressor input.

Design перепускного the valve of dump of pressure

1  —  From the compressor
2  —  To the inlet pipeline
3  — the  Spring
4  — the  Diaphragm
5  —  On a compressor input

 


Diagnostics of malfunctions of system of a turbo-supercharging

Infringements of functioning of system of a turbo-supercharging can lead to following consequences:

At a pressurisation elevated pressure:

    a) the Detonation of an air-fuel mix.

At the underestimated pressure of pressurisation:

The reasons of occurrence listed below signs infringement of tightness of systems of an admission of air or release of the fulfilled gases, increase of resistance of a final path as a result of deformation of pipes, control system refusal on detonation elimination, and also infringement of serviceability of functioning of a control system of injection can be also.


    b) capacity Loss
    c) Decrease приемистости;
    d) Increase of the expense of fuel.

At oil leaks:

    e) the Raised expense of oil;
    f) Formation of a white smoke on an exit of system of release of the fulfilled gases.