"Gazelle" Gas-2705>> The engine>> Engines ZMZ-4025,-4026>> The gazoraspredelitelnyj mechanism

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




The inlet pipe is made of an aluminium alloy, a final collector (fig. 4.7) — from pig-iron. The inlet pipe and a final collector of 1st and 4th cylinders are connected among themselves in one knot through a lining by four hairpins, and their plane прилегания to a head of cylinders is processed in gathering with неплоскостностью 0,2 mm, therefore knot dismantling is needlessly undesirable.
The average part of an inlet pipe is warmed up by the fulfilled gases which are passing on a final collector. Heating degree can be regulated manually by means of turning заслонки 3 depending on a season. At sector 2 turn in position at which a label "winter" is against a lock hairpin, heating of a mix the greatest; at turn in position of a label "summer" heating the least.
Camshaftpig-iron, cast with a steel gear wheel of a drive of the oil pump and the ignition gauge-distributor; has five basic necks of different diameters (for convenience of assemblage): the first — 52 mm, the second — 51 mm, the third — 50 mm, the fourth — 49 mm, the fifth — 48 mm. Necks lean directly against a surface расточек in the aluminium block of cylinders. The working surface of cams and the clown of a drive of the fuel pump is bleached to high hardness at camshaft casting. Teeths of a gear wheel of a drive of the oil pump are tempered.
Profiles of inlet and final cams are identical. Cams on width шлифованы on a cone. The conic surface of a cam in a combination to a spherical end face of a pusher at engine work informs a pusher a rotary motion. Thereof deterioration directing a pusher and its end face becomes uniform and small.

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




The camshaft 7 (fig. 4.8) is resulted in rotation from a cranked shaft косозубой by a 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. Textolite application provides noiselessness of work of gear wheels. Both gear wheels have on two apertures with carving М8х1,25 for a stripper.
The camshaft rotates in 2 times more slowly the cranked. From axial movings the camshaft is kept 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 backlash of 0,1-0,2 mm. The axial backlash is provided распорным with a ring 8 clamped between a gear wheel and a neck of a shaft. For improvement extra earnings of a surface of a persistent flange фосфатированы. The gear wheel is fixed on distributive to a shaft by means of a washer 2 and a bolt 1 with carving M12х1,25. The bolt is screwed in a shaft end face.

Fig. 4.9. Adjusting labels on distributive gear wheels




On a gear wheel of a cranked shaft against one of teeths the label 0 is put, and against a corresponding hollow of a gear wheel of a camshaft is put risk or засверловка. At camshaft installation these labels should be combined (fig. 4.9).
The camshaft provides following phases газораспределения: the inlet valve opens with an advancing on 12 before piston arrival in ВМТ, is closed with delay on 60 after piston arrival in НМТ, the final valve opens with an advancing on 54 before piston arrival in НМТ and is closed with delay on 18 after piston arrival in ВМТ. The specified phases газораспределения are valid at a backlash between коромыслом and the valve, equal 0,5 mm.
Height of lifting of valves — 10 mm.
Pusherssteel, piston type. A pusher end face наплавлен the bleached pig-iron and шлифован on sphere in radius of 750 mm (camber of the middle of an end face is equal 0,11 mm). In a pusher there is a spherical deepening in radius of 8,73 mm for the bottom end of a bar. Near to the bottom end face for a drain of oil two apertures are made of an internal cavity of a pusher.
Pushers on external diameter and apertures under pushers in the block of cylinders are broken on two dimensional groups. At assemblage pushers of certain group should be established in the apertures noted by the corresponding paint (tab. 4.4).

Table 4.4. Dimensional groups of pushers


Bars of pushers. For maintenance of stability of backlashes in клапанном the mechanism at heating and cooling of the engine of a bar of pushers are made from dural прутка. On the ends of bars напрессованы the steel tempered tips with spherical end faces. The bottom tip interfaced to a pusher, has an end face with radius of sphere 8,73 mm, and top, entering into deepening in the adjusting screw коромысла, — 3,5 mm. Length of a bar for the engine 4025 — 287 mm and for the engine 4026 — 283 mm.

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




Коромысла valves 8 (fig. 4.10) identical to all клaпaнoв, стaльныe, cast. In a nave aperture коромысла запрессована the plug curtailed from sheet оловянистой of bronze. On an internal surface of the plug the flute for uniform distribution of oil on all surface and for its supply to an aperture in a short shoulder коромысла is made. The long shoulder коромысла comes to an end with the tempered cylindrical surface leaning against an end face of the valve 2, and a short shoulder — a carving aperture for the adjusting screw.
The adjusting screw 9 has шестигранную a head with spherical deepening for a bar, and from the top end — a cut for a screw-driver. Spherical deepening is connected сверлеными by channels with проточкой on a carving part of the screw. Проточка on the screw is opposite to an aperture in a shoulder коромысла, i.e. Approximately in the middle of height of a carving lug of a short shoulder коромысла. Oil in this case free passes from the channel коромысла in the screw channel. The adjusting screw is stopped by a counternut 10.
Коромысла - are established on a hollow steel axis which is fixed on a head of cylinders by means of four basic racks from the high-strength pig-iron, two additional racks from malleable cast iron and the hairpins passed through racks. The fourth basic rack on a plane adjoining to a head of cylinders, has a groove through which oil from the channel in a head in an axis cavity коромысел is brought. Other racks of the milled groove have no, therefore they cannot be put to the place of the fourth rack. From axial moving коромысла are kept распорными by the springs pressing коромысла to racks. Extreme коромысла are between additional and basic racks. For wear resistance increase the external surface of an axis under коромыслами is tempered. Under everyone коромыслом in an axis the aperture for greasing is made.
Valves are made of heat resisting steels: the inlet valve — from хромокремнистой, final — from хромоникельмарганцовистой with a nitrogen additive. On a working facet of the final valve in addition наплавлен heat more resisting хромоникелевый an alloy. 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 сухариков plates of a spring of the valve is executed. Plates of springs of valves 6 (fig. 4.10 see) and сухарики 7 are made of a steel and subjected superficial hardening.
On each valve it is established on two springs: external 4 with variable step with left навивкой and internal 5 with right навивкой. Springs are made of thermally processed high-strength wire and subjected дробеструйной to processing. Under springs steel washers 12 are established. The external spring is established downwards by the end having a smaller step of coils. Valves work in ceramic-metal directing plugs. Plugs are made by pressing with the subsequent sintering of a mix of iron, copper and graphite powders with addition for wear resistance increase дисульфида molybdenum. The internal aperture of plugs is definitively processed after them запрессовки in a head. The plug of the inlet valve is supplied by the lock ring interfering spontaneous moving of the plug in a head.
For reduction of quantity of the oil getting through backlashes between the plug and a core of the valve, by the top ends of all plugs напрессованы маслоотражательные the caps 3 made from маслостойкой of rubber.
The distributive mechanism is closed from above by a cover коромысел, stamped of a sheet steel, with the filtering element of system of ventilation fixed from the inside картера. The cover коромысел fastens through a rubber lining to a head of cylinders six screws.