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DETAILS OF THE TIMING
The camshaft opens and closed opment of valves of gas distribution mechanism in the definition Lenno sequence in accordance with the order of the the cylinders of the engine. The camshafts must be forged of steel with an after- blowing cementation and hardening by high-frequency h- toty. On some engines the shafts are cast from high durable cast iron. In these cases, the surface of Cams and necks the shaft is then sanded and bleached. To reduce the tre tion between tails and legs are pressed into the holes steel, coated with an antifriction coating, or metal lacerations sleeve. Between the supporting necks of the camshaft RAS relying Cams, two for each cylinder — an inlet and prom. In addition, shaft mounted gear for drive the oil pump and the breaker-distributor and there are eccentric to drive the fuel pump. Gears camshafts are made from Chu- guna or PCB, drive distribution gear- Terny crankshaft is made of steel. The teeth of the gears Ko see, which causes the axial displacement of the shaft. For warn- a facility is provided for axial displacement of the thrust flange, which is attached to the cylinder block between the end re- days bearing journal and hub of the distributor gear In four-stroke engines the workflow is going on- dit for four stroke or two revolutions of the crankshaft. This is possible if the camshaft at this time A device for limiting axial displacement and the distribution- dividing the shaft will do two times fewer rotations. Therefore, dia- meter gear installed on the distributor shaft, doing two times larger than the diameter of the gear kalena- that of the shaft. For proper operation of the engine the cranks of kolena- in the shaft and the Cams of the camshaft must be located- be carried out strictly in a certain position relative to each other. Therefore, during Assembly of the engine distribution gear will change the gear according to their sub- ies labels: one on the gear tooth of the crankshaft, and the other between two teeth of a gear are distributed evenly. inflammatory shaft. On engines with a block distribution inflammatory gears, installing them is also labels . The pushers transfer the force from the Cams control shaft relatively to the rod. They are made from cast iron and STA- . The combination of the labels of distributive pinion gears Lee. The plungers are cylindrical, mushroom or roller and have a spherical dimples, at Ko which includes the lower ends of the rods. Move tol- kateli in guides formed in the block cylinder- the ditch or in an attached special build- Mar. To prevent uneven wear of their RA- working surfaces of pushers all the time turn around their axes due to the convex surfaces of their lower- her head and the beveled Cam surface of the Cam- inflammatory shaft. Rods transmit the force from the tappets to the rocker arms and made in the form of hollow cylindrical rods from steel with hardened tips or duralumin- niewyk tubes are pressed from both sides of the convex- ski steel tips. Rod rests with one hand into the recess of the follower, and in sferi- cal surface of the adjusting screw rocker arm. The rocker transmits the force from the rod to the valve. You discharging it in the form of two shoulders of the lever, planted on the axis. The shoulder of the rocker arm with the valve side is longer than with the one-hundred- Rhone rod-pusher that allow to reduce the height lift the push rods. The short arm of the rocker screwed the adjustment screw with locknuts for installation heat clearance in the valve mechanism. To reduce friction of the rocker arm about the axis of the hole is pressed Bron- gas bushing. Install the rocker arms on a hollow steel the axes, which are common to all cylinders or are made separately for each cylinder. The axis of relation- are in the racks on the engine cylinder head. From Pro- longitudinally moving the rocker is held with the help- the soup springs. Valves are used to periodically open and closed opment of holes of inlet and outlet channels depending- t from the position of the piston in the cylinder and from work engine. The valve consists of a flat disc heads key and rod. The head has a narrow working edge — FAS- ku, angled at 45 ° or 30°. Head diameter vpus- knogo valve larger than the exhaust that provides faster filling of the combustion chamber of the cylinder Zaria the house of the combustible mixture. The intake valves are made of chromium steel; exhaust valves or heads of heat-resistant STA- Lee. Valve seats pressed into the head or block qi lindros and are made from heat-resistant cast iron. On a facet 36 the valve head sometimes napravlyayut heat-resistant alloy. The chamfer of the valve head must be flush to the chamfered edge valve seat. To this end the mating surfaces of the in- will tirhut. Since the exhaust valve due to washing it the exhaust gases experiences a large temperature load compared to the inlet valve, its rod filled with metallic sodium. Sodium metal has high thermal conductivity and low temperature melting, thus promoting the dissipation of heat from the head to ster- GNU, then to the guide Bush. Exhaust valves can also have the mechanism of their forced provera- zivania at work, which prevents them from seizing and algo- finally. The valve seat is pressed with one or two valve- local springs (in the latter case, the springs should to have a different direction of turns for the purpose of clearing Cole- Bani). The valve stem is cylindrical and in the upper part has a recess for fixing the mountings valve spring. The rods of the valves are moved by a cast-iron or ceramic guide bushing force-fitted round plain Sovana in the cylinder head of the engine. To prevent the ingress of oil into the chamber shore- of the cylinder through the clearance between the valve stem and its on- sending a bushing put seal maslobenzostojkie- tion of rubber in the form of a cap or gland. At the present time in the manufacture of engines is easy- new cars are increasingly used cardboard design, when each cylinder has two inlet and two exhaust valve. Together with charac- ahead of the spark plug in the center of the combustion chamber is improves the filling of cylinders with fresh charge of a combustible mixture, reduces the time of combustion of the working mixture and improves fuel efficiency of the engine. |
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