2.4.3. Camshaft phase-shifter (F4R, K4M engines)

Operating modes of the phase-shifter (K4M engine)
Work and control of the phase-shifter (F4R engine)

The phase-shifter is intended for change of phases of gas distribution.

Fig. 2.228. Camshaft phase-shifter: 1 – phase-shifter

For improvement of filling of cylinders by working mix on all modes K4M and F4R engines are equipped with the phase-shifter of the camshaft of inlet valves (fig. 2.228).
Shift of the moment of closing of inlet valves optimizes filling of cylinders depending on the frequency of rotation of a bent shaft. As a result the torque on the mode of average loadings and power increases with a high frequency of rotation of a bent shaft.
In these conditions later closing of inlet valves provides receipt of an additional portion of fuel mix at the expense of the high speed of its movement.
On the contrary, with a low frequency of rotation inertia of a charge is small. Earlier closing of final valves allows to avoid bad filling of cylinders and loss of torque owing to replacement of a part of a fresh charge of mix.
The frequency of rotation of a bent shaft is higher, the later there has to be a closing of inlet valves.