5.1.3. Six-cylinder diesel engines
Fig. 4.5. A motor compartment with the diesel engine 300 D: 1 – the cooled box from plastic for electronic regulators and relay blocks; 2 – lattice of an air inlet of ventilation of salon; 3 – case of valves of adjustment of pressure; 4 – cover of office of nozzles and spark plugs; 5 – screen wiper drive; 6 – oil filter; 7 – inlet collector; 8 – a tank for brake fluid with the main brake cylinder and the amplifier of brakes; 9 – block of safety locks and relay; 10 – broad tank; 11 – air filter; 12 – perepuskny valve of final system; 13 – masloizmeritelny probe; 14 – cover of an oil-filling mouth; 15 – petrol filter; 16 – spare capacity of hydraulic oil for a servoupravleniye; 17 – a washer reservoir (in front — for headlights, behind — for a screen wiper); 18 – brake unit
|
Along with 5-cylinder Mercedes turbo engines offers the 6-cylinder diesel engine with a volume of cylinders of 3 l (OHM 606) (fig. 4.5). Technically the OHM 606 almost completely corresponds to the OHMS models 604 and OHM 605 with smaller number of cylinders (2,5 l, 5 tsit.). It is equipped with a head of the block of cylinders with forkamery and four valves on the cylinder, electronic control, line TNVD, a two-mass flywheel (at models with the mechanical transmission). The bent shaft of the 6-cylinder engine is established on seven basic bearings. Exclusive feature of OHMS 606 is the inlet collector regulated on length in the form of the three-stage resonant soaking-up branch pipe with gates.
Fig. 4.6. A motor compartment with the diesel engine 320 CDI: 1 – broad tank; 2 – air filter; 3 – channel of air supply of a turbocompressor; 4 – the cooled box for electronic regulators and relay blocks; 5 – cover of an oil-filling mouth; 6 – lattice of an air inlet of ventilation of salon; 7 – engine cover; 8 – cover of an inlet collector; 9 – a tank for brake fluid with the main brake cylinder and the amplifier of brakes; 10 – masloizmeritelny probe; 11 – sound signal; 12 – protective front grille; 13 – radiator hose; 14 – cover of the petrol filter; 15 – a washer reservoir (in front — for headlights, behind — for a windshield screen wiper); 16 – control unit of the brake system; 17 – spare capacity of hydraulic oil with a servoregulyator; 18 – block of safety locks and relay
|
Since August, 1999 began to install the engine 320 CDI (fig. 4.6) with the Common Rail system which replaced E 300 of D on the Mercedes cars.
All engines CDI are carried out on modular system, they have identical distance between cylinders (97 mm) both identical diameters and the working course (88 x 88,34 mm). At the same time engines CDI received a new head of cylinders with four valves, tsentralnoraspolozhenny nozzles and an aluminum design.
Fig. 4.9. The piston with a rod: 1 – the piston with three piston rings; 2 – rod; 3 – cover of the basic bearing
|
Fig. 4.10. Two-mass flywheel: 1 – bent shaft; 2 – forward part of a flywheel; 3 – quencher of tortional fluctuations; 4 – back part of a flywheel
|
Fig. 4.11. A longitudinal section of the 4-cylinder diesel engine with forkamerny injection (OHM 604): 1 – the fan from viskomufty; 2 – oil probe; 3 – chain of the drive of camshafts; 4 – oil-filling mouth; 5 – inlet collector; 6 – a branch pipe from the case of the operating valve; 7 – oil filter; 8 – starter; 9 – two-mass flywheel; 10 – a rod with the piston; 11 – bent shaft; 12 – reception funnel of the oil pump; 13 – oil pump; 14 – chain of the drive of the oil pump
|
Fig. 4.12. A cross-section of the 4-cylinder diesel engine with forkamerny injection (OHM 604): 1 – reception highway of inlet system; 2 – inlet collector; 3 – glow plugs; 4 – TNVD drive gear wheel; 5 – conrod shaft of a bent shaft; 6 – gear wheel of the drive of the oil pump; 7 – oil level sensor; 8 – cooling system thermostat; 9 – final branch pipe; 10 – the channel of recirculation of the fulfilled gases; 11 – the valve of recirculation of the fulfilled gases; 12 – the case of the operating valve
|
Fig. 4.15. Collaboration of the camshaft and valves: 1 – cover of a head of cylinders; 2 – casing of a head of cylinders; 3 – camshaft of final valves; 4 – pushers with hydraulic adjustment of a gap; 5 – injection nozzle; 6 – final valve; 7 – a forkamer with the inlet channel to the combustion chamber; 8 – inlet channel; 9 – nozzle; 10 – camshaft of inlet valves
|
Fig. 4.16. Provisions of the piston: 1 – top dead point; 2 – working course; 3 – lower dead point; 4 – combustion chamber; 5 – head of the block of cylinders
|
TECHNICAL DICTIONARY
The basic concepts about operation of engines
Four-cycle principle of work.
Admission (1st step): the piston goes down to the lower dead point; the inlet valve opens, the forced air moves in the cylinder.
Compression (2nd step): the piston goes from the lower dead point to top; the inlet valve is closed; under pressure of the piston air compresses.
Combustion (3rd step): from compression temperature fuel ignites, fuel mix at combustion pushes the piston to the lower dead point, and the rod turns a bent shaft.
Release (4th step): the piston goes again upward, the final valve is open, and the fulfilled gases go to system of release.
Working volume of the cylinder. The volume of the cylinder at which the piston passes from the lower dead point to top is called working volume. On reaching the piston of the top dead point there is still a small space of the combustion chamber. The combustion chamber and working volume are shown in fig. 4.16.
Extent of compression. It is the characteristic of a ratio between the working volume of the cylinder and volume of the combustion chamber. It shows, in how many time gas mixture before ignition is condensed.
|
PREVENTION
Repair of knots and details on engines demands high qualification and the special tool. All works need to be carried out only on specialized STOA.
|