2.11.2. Adjustment of gaps in the mechanism of the drive of valves


Fig. 2.46. Mechanism of the drive of valves: 1 – head of cylinders; 2 – valve; 3 – pusher; 4 – case of bearings of the camshaft; 5 – camshaft; 6 – adjusting washer; 7 – maslootrazhatelny cap; And — a gap between a cam and an adjusting washer
The gap And (see fig. 2.46) between cams of the camshaft and adjusting washers on the cold engine has to be (0,2 ±0,05) mm for inlet valves and (0,35 ±0,05) mm — for final. The gap is regulated by selection of thickness of adjusting washers 6.
In spare parts adjusting washers from 3 to 4,5 mm thick with an interval through each 0,05 mm are delivered. Thickness of a washer is marked on its surface.
Regulate a gap in the following order:
– uncover heads of cylinders and a forward protective cover of a gear belt;
– turn out spark plugs a key 67.7812.9515 and remove oil from the top part of a head of cylinders;
– examine a surface of cams of the camshaft: on them there should not be zadir, sinks, wear and deep рисок;
– install the device 67.7800.9503 for an utaplivaniye of pushers of valves on hairpins of fastening of a cover of a head of cylinders;

Fig. 2.25. Check of coincidence of adjusting tags on a pulley of the camshaft and a back protective cover

– turn a bent shaft before combination of adjusting tags on a pulley and a back cover of a gear belt (see fig. 2.25), and then tighten it on 40-50 ° (2,5–3 teeth on a camshaft pulley). At the same time in the first cylinder there will be a combustion phase;

       PREVENTION
It is necessary to turn a bent shaft only clockwise or for a bolt of fastening of a pulley of the drive of the generator, or for a camshaft pulley by means of adaptation 67.7811.9509.
It is impossible to turn a bent shaft for a bolt of fastening of a pulley of the camshaft as at the same time it is possible to damage a bolt.


– check a set of probes gaps at the 1st and 3rd cams of the camshaft;

Fig. 2.47. Utaplivaniye of pushers of valves when replacing an adjusting washer: 1 – adaptation 67.7800.9503; 2 – pusher

Fig. 2.48. Fixation of pushers of valves when replacing an adjusting washer: 1 – clamp 67.7800.9504; 2 – adjusting washer

– if the gap differs from norm, then adaptation 67.7800.9503 (fig. 2.47) drown a pusher and record it in the lower situation, having established a clamp of 67.7800.9504 (fig. 2.48) between edge of a pusher and the camshaft;
– remove with adaptation 67.7800.9505 an adjusting washer and measure by a micrometer its thickness;
– determine thickness of a new washer by a formula:
N = IN + (AND — C),
where       And — the measured gap, mm;
               In — thickness of the removed washer, mm;
               With — a nominal gap, mm;
               N — thickness of a new washer, mm.

Example. Let's allow mm A=0,26; In =3,75 mm; From =0,2 mm (for the inlet valve), then:
N = 3,75 + (0,26–0,2) = 3,81 mm.
Within the admission on a gap of ±0,05 mm we accept thickness of a new washer, equal 3,8 mm.
– establish in a valve pusher a new adjusting washer by marking towards a pusher, remove a clamp 67.7800.9504 and double-check a gap. If it is adjusted truly, then the probe 0,2 or 0,35 mm thick has to enter with easy jamming;
– consistently turning a bent shaft half way that corresponds to turn of a tag on a camshaft pulley on 90 °, adjust gaps at other valves, observing the sequence specified in table 2.2;

  The table 2.2 Order of Adjustment of Gaps in the mechanism of the drive of valves
Angle of rotation of a bent shaft from the provision of the combined tags, a hail
   Cams *
final
inlet
40-50
1
3
220-230
5
2
400-410
8
6
580-510
4
7
* Numbers of cams are specified one after another from a camshaft pulley.

– fill in oil in the top part of a head of cylinders, establish a cover of a head of cylinders and a forward cover of a gear belt.