The displacement of the closing moment of the intake valves optimizes the filling of the cylinders depending on the speed of the crankshaft. The result is increased torque at medium loads and power at high engine speeds.
Camshaft phase regulator:
1 - phase regulator
Under these conditions, the later closing of the intake valves ensures the supply of an additional portion of the fuel mixture due to the high speed of its movement.
On the contrary, at a low rotational speed, the inertia of the charge is small. Early closing of the exhaust valves avoids poor filling of the cylinders and loss of torque due to the displacement of part of the fresh charge of the mixture.
The higher the crankshaft speed, the later the intake valves should close.
Modes of operation of the phase regulator (K4M engine)
Oil is supplied to the phase regulator through a solenoid valve mounted on the cylinder head.
Phase regulator solenoid valve:
1 - valve
The valve is energized in the form of a variable signal of the degree of cyclic opening (amplitude 12 V and frequency 250 Hz), which allows you to supply oil to the mechanism, and thus change the phase angle.
The ECU feeds the solenoid valve with a variable cyclic opening degree signal, the magnitude of which is proportional to the required phase shift.
The phases change smoothly from 0 to 43°along the angle of rotation of the crankshaft.
The camshaft dephaser solenoid valve is controlled under the following conditions:
- no malfunction of the crankshaft speed sensor;
- no faults in the camshaft position sensors;
- no malfunctions in the injection system;
- after starting the engine;
- when the engine is not idling with the accelerator pedal released;
- the threshold value of the injection profile is obtained, which is set taking into account the load and the crankshaft speed;
- coolant temperature within 10-120°C;
- elevated engine oil temperature.
Backup Modes:
- return of the phase regulator to its original position;
- zero phase shift.
Attention. When the solenoid valve is blocked in the open position, the engine idles unsteadily, the pressure in the intake manifold is increased, and there is also increased engine noise.
Operation and control of the phase regulator (engines M4R, H4J)
The phase shifter is disabled or controlled by the injection computer via a solenoid valve located on the cylinder head cover.
When the crankshaft speed is in the range of 1500-4300 rpm, the ECU supplies power to the solenoid valve.
Phase regulator solenoid valve:
1 - valve
When 4300 rpm is exceeded, the power supply to the solenoid valve is cut off. At the same time, the position of the phase regulator mechanism contributes to filling the cylinders at a high crankshaft speed. In this position, the locking plunger blocks the mechanism.
Note. At speeds up to 1500 rpm, no supply voltage is applied to the solenoid valve. The mechanism is blocked by a plunger. From the moment power is applied to the solenoid valve at a crankshaft speed of more than 1500 rpm, under the influence of oil pressure, the locking plunger moves away and releases the mechanism.
In the initial position, the solenoid valve is closed. The valve opens the oil passage to control the phase regulator under the following conditions:
- no malfunction of the crankshaft speed sensor;
- no faults in the camshaft position sensors;
- no malfunctions in the injection system;
- after starting the engine;
- the engine is not idling;
- the battery voltage is higher than 11.4 V;
- coolant temperature above 30°C;
- engine speed is 1500 - 4300 rpm;
- load over 87% (approx. 900 mbar).
Attention. When the solenoid valve is locked in the open position, the engine will melt unsteadily at idle, the pressure in the intake manifold is increased.