2.1.2.3. Main characteristics of operation of the mechanism of change of phases of gas distribution

The executive mechanism of change of phases of gas distribution has two hydraulic compartments: cut advancings of the moment of opening or closing of the valve and cut delays of opening or closing of the valve. Compartments settle down between the integrated case of an asterisk of the camshaft and a rotor of a cam-shaft. The oil pump gives engine oil to each compartment. Hydraulic pressure in each compartment is controlled by the oil operating valve (OCV), and relative phases of an asterisk of the camshaft and a cam-shaft change for receiving the optimum moment of opening or closing of valves according to operating conditions of the engine.

When the pin in the executive mechanism of change of phases of gas distribution rests against a rotor which under the influence of a spring is in the provision of the maximum delay of opening or closing of valves, the asterisk of the camshaft and a cam-shaft rotate as a uniform detail. When pressure of oil increases, and the pin departs from a rotor, becomes possible to modify the mutual angular provision of an asterisk of the camshaft and a cam-shaft.

Fig. 2.33. The scheme of circulation of oil during an advancing of opening or closing of valves: 1 – PCM block; 2 – the oil operating valve (OCV); 3 – spool-type valve; 4 – oil pump; 5 – cam-shaft; 6 – executive mechanism of change of phases of gas distribution; 7 – rotor; 8 – case; 9 – oil pallet; 10 – to a compartment of an advancing of opening or closing of valves; 11 – cut advancings of opening or closing of valves; 12 – from a compartment of delay of opening or closing of valves

When the spool-type valve in the oil operating valve (OCV) moves according to a PCM block signal on the left, oil under pressure gets to the canal of an advancing of opening or closing of valves and to a compartment of an advancing of opening or closing of valves in the executive mechanism of change of phases of gas distribution. Then the rotor integrated with a cam-shaft rotates in the direction of an advancing of opening or closing of valves, against the case which is put in action from a bent shaft, and the moment of opening or closing of valves moves towards an advancing (fig. 2.33).

Fig. 2.34. The scheme of circulation of oil during delay of opening or closing of valves: 1 – PCM block; 2 – the oil operating valve (OCV); 3 – spool-type valve; 4 – oil pump; 5 – cam-shaft; 6 – executive mechanism of change of phases of gas distribution; 7 – rotor; 8 – case; 9 – oil pallet; 10 – to a compartment of delay of opening or closing of valves; 11 – cut delays of opening or closing of valves; 12 – from a compartment of an advancing of opening or closing of valves

When the spool-type valve in the oil operating valve (OCV) moves according to a PCM block signal to the right, oil from the oil pump under pressure moves to the canal of delay of opening or closing of valves and in a compartment of delay of opening or closing of valves of the executive mechanism of change of phases of gas distribution. Then the rotor integrated with a cam-shaft turns in the direction of delay of opening or closing of valves, against the case which is put in action from a bent shaft, and the moment of opening or closing of valves moves towards delay (fig. 2.34).

Fig. 2.35. The scheme of circulation of oil during intermediate opening or closing of valves: 1 – PCM block; 2 – the oil operating valve (OCV); 3 – spool-type valve; 4 – to a compartment of an advancing of opening or closing of valves; 5 – to a compartment of delay of opening or closing of valves

The spool-type valve in the oil operating valve (OCV) settles down in an intermediate position. Hydraulic pressure remains both in an advancing compartment, and in a compartment of delay of the executive mechanism of change of phases of gas distribution. At the same time the angle of mutual turn of a rotor and the case does not change that gives the fixed moment of opening or closing of valves (fig. 2.35).