5.1.3. Gas-distributing mechanism


Fig. 4.7. Inlet pipe and final collector: 1 — a nut; 2 — the sector of adjustment of heating; 3 — the gate; 4 — a final collector; 5 — an inlet pipe; And — position of the gate at the smallest heating — "summer"; In — position of the gate at the greatest heating — "winter"




The inlet pipe is made of aluminum alloy, a final collector (fig. 4.7) — of cast iron. The inlet pipe and a final collector of the 1st and 4th cylinders are connected among themselves in one knot through laying by four hairpins, and their plane of a prileganiye to a head of cylinders is processed assembled with not planeness of 0,2 mm therefore dismantling of knot is needlessly undesirable.
The middle part of an inlet pipe is warmed up by the fulfilled gases passing on a final collector. Extent of heating can be regulated manually by means of the turning gate 3 depending on a season. At turn of sector 2 in situation at which a tag "winter" is against a lock hairpin, mix heating the greatest; at turn in the provision of a tag "summer" heating the smallest.
The camshaft — pig-iron, cast with a steel gear wheel of the drive of the oil pump and sensor distributor of ignition; has five basic necks of different diameters (for convenience of assembly): the first — 52 mm, the second — 51 mm, the third — 50 mm, the fourth — 49 mm, the fifth — 48 mm. Necks lean directly on the surface of boring in the aluminum block of cylinders. The working surface of cams and the clown of the drive of the fuel pump is bleached to high hardness when casting the camshaft. Teeths of a gear wheel of the drive of the oil pump are tempered.
Profiles of inlet and final cams are identical. Cams on shlifovana width on a cone. The conic surface of a cam in a combination to a spherical end face of a pusher during the operation of the engine reports to a pusher rotary motion. Thereof wear of a guide of a pusher and its end face becomes uniform and small.

Fig. 4.8. Camshaft drive: 1 — a bolt; 2 — a washer; 3 — a spline; 4 — a gear wheel; 5 — a cover of distributive gear wheels; 6 — a persistent flange; 7 — the camshaft; 8 — the expansion plug




The camshaft 7 (fig. 4.8) is given to rotation from a bent shaft by a kosozuby gear wheel 4. On cranked to a shaft there is a steel gear wheel with 28 teeths, and on distributive to a shaft — a textolite gear wheel with 56 teeths. Use of textolite provides noiselessness of work of gear wheels. Both gear wheels have two openings with a carving of M8x1,25 for a stripper.
The camshaft rotates twice more slowly than cranked. The camshaft refrains from axial movements by a persistent steel flange 6 which is located between an end face of a neck of a shaft and a nave of a gear wheel with a gap of 0,1 — 0,2 mm. The axial gap is provided with the expansion ring 8 clamped between a gear wheel and a neck of a shaft. For improvement extra earnings of a surface of a persistent flange of a fosfatirovana. The gear wheel is fixed on distributive to a shaft by means of a washer 2 and a bolt 1 with a carving of M12x1,25. The bolt is screwed in a shaft end face.

Fig. 4.9. Adjusting tags on distributive gear wheels




On a gear wheel of a bent shaft against one of teeths the tag "0" is put, and against the corresponding hollow of a gear wheel of the camshaft it is put risk or a zasverlovka. At installation of the camshaft these tags have to be combined (fig. 4.9).
The camshaft provides the following phases of gas distribution: the inlet valve opens with an advancing on 12 ° before arrival of the piston to VMT, is closed with delay on 60 ° after arrival of the piston to NMT, the final valve opens with an advancing on 54 ° before arrival of the piston to NMT and is closed with delay on 18 ° after arrival of the piston to VMT. The specified phases of gas distribution are valid at a gap between a yoke and the valve, equal 0,5 mm.
Height of raising of valves — 10 mm.
Pushers — steel, piston type. The end face of a pusher is built up by the bleached cast iron and шлифован on the sphere with a radius of 750 mm (camber of the middle of an end face is equal to 0,11 mm). In a pusher there is a spherical deepening with a radius of 8,73 mm for the lower end of a bar. Near the lower end face two openings for an oil drain are made of an internal cavity of a pusher.
Pushers on outer diameter and openings under pushers in the block of cylinders are broken into two dimensional groups. At assembly pushers of a certain group should be established in the openings noted by the corresponding paint (tab. 4.4).

Table 4.4. Dimensional groups of pushers


Bars of pushers. For ensuring stability of gaps in the valvate mechanism when heating and cooling the engine of a bar of pushers are made of a dural bar. For the ends of bars of a napressovana the steel tempered tips with spherical end faces. The lower tip which is interfaced to a pusher has an end face with a radius of sphere of 8,73 mm, and top, entering deepening in the adjusting screw of a yoke — 3,5 mm. Bar length for the engine of 4025 — 287 mm and for the engine of 4026 — 283 mm.

Fig. 4.10. Drive of valves: 1 — a valve saddle; 2 — the valve; 3 — a maslootrazhatelny cap; 4 and 5 — springs; 6 — plates of springs; 7 — a cracker; 8 — a yoke; 9 — the adjusting screw; 10 — a nut of the adjusting screw; 11 — a bar; 12 — a basic washer of springs




Yokes of valves 8 (fig. 4.10) identical to all valves, steel, cast. In an opening of a nave of a yoke the plug curtailed from sheet olovyanisty bronze is pressed. On the internal surface of the plug the flute for uniform distribution of oil on all surface and for its supply to an opening in a short shoulder of a yoke is made. The long shoulder of a yoke comes to an end with the tempered cylindrical surface leaning on a valve 2 end face, and a short shoulder — a carving opening for the adjusting screw.
The adjusting screw 9 has a six-sided head with spherical deepening for a bar, and since the top end — a cut for the screw-driver. Spherical deepening is connected by sverleny channels to a pro-point on a carving part of the screw. The pro-point on the screw is opposite to an opening in a yoke shoulder, i.e. approximately in the middle of height of a carving lug of a short shoulder of a yoke. Oil in this case freely goes from the channel of a yoke to channel of the screw. The adjusting screw is stopped by a lock-nut 10.
Yokes - are established on a hollow steel axis which is fixed on a head of cylinders by means of four main racks from high-strength cast iron, two additional racks from the malleable cast iron and hairpins passed through racks. The fourth main rack on the plane adjacent to a head of cylinders, has a groove through which oil from the channel in a head in a cavity of an axis of yokes is brought. Other racks of the milled groove have no therefore they cannot be put to the place of the fourth rack. Refrain from axial movement of a yoke by the expansion springs pressing yokes to racks. Extreme yokes are between additional and main racks. For increase in wear resistance the external surface of an axis under yokes is tempered. Under each yoke in an axis the opening for lubricant is made.
Valves are manufactured from heat resisting staly: the inlet valve — from chromosiliceous, final — from hromonikelmargantsovisty with nitrogen additive. On a working facet of the final valve more heat-resistant chromonickel alloy is built in addition up. Diameter of a core of valves — 9 mm. The plate of the inlet valve has diameter of 47 mm, and final — 39 mm. A corner of a working facet of both valves — 45 °. On the end of a core of valves bore for plate croutons of a spring of the valve is executed. Plates of springs of valves 6 (see fig. 4.10) and croutons 7 are made of steel and subjected to superficial hardening.
On each valve about two springs are established: external 4 with a variable step with the left navivka and internal 5 with the right navivka. Springs are made of thermally processed high-strength wire and subjected to bead-blasting processing. Under springs steel washers 12 are established. The external spring is established by the end having a smaller step of rounds down. Valves work in the ceramic-metal directing plugs. Plugs are manufactured by pressing with the subsequent agglomeration of mix of iron, copper and graphite powders with addition for increase in wear resistance of a disulfide of molybdenum. The internal opening of plugs is finally processed after their press fitting in a head. The plug of the inlet valve is supplied with the lock ring interfering spontaneous movement of the plug in a head.
For reduction of amount of the oil getting through gaps between the plug and a core of the valve by the top ends of all plugs of a napressovana the maslootrazhatelny caps 3 made of oilproof rubber.
The distributive mechanism is closed from above by a cover of yokes, stamped of sheet steel, with the filtering element of system of ventilation of a case fixed from the inside. The cover of yokes fastens through rubber laying to a head of cylinders six screws.