GF27.60-P-4013G Shift From 1 to 2, Function

GF27.60-P-4013G Shift from 1 to 2, function
- TRANSMISSION 722.6











Aim
Engage front multiple-disc clutch (K1), disengage front multiple-disc brake (B1).

Operation

1st gear engaged
The end face of the 1-2/4-5 command valve (31a) is kept depressurized via the 1-2 and 4-5 shift solenoid valve (Y3/6y3). Via the 1-2/4-5 holding pressure shift valve (28a), working pressure (p-A) is applied to the front multiple-disc brake (B1). The front multiple-disc clutch (K1) is depressurized.

Shift phase
Via the 1-2 and 4-5 shift solenoid valve (Y3/6y3), the shift valve pressure (p-SV) is directed onto the end face of the command valve 1-24-5 (31a). The 1-2/4-5 command valve (31a) is displaced and the shift pressure (p-S) coming from the 1-2/4-5 shift pressure shift valve (29a) via the 1-2/4-5 command valve (31a) is directed to the front multiple-disc clutch (K1). At the same time the front multiple-disc brake (B1) is subjected to overlap pressure from the 1-2/4-5 overlap regulating valve (30a).

The B1 pressure acting on the end face of the 1-2/4-5 shift pressure shift valve (29a) is superseded by the working pressure (p-A). The increasing shift pressure (p-S) at the front multiple-disc clutch (K1) acts on the annular area of the 1-2/4-5 overlap regulating valve (30a) and reduces the overlap pressure regulated by the 1-2/4-5 overlap regulating valve (30a). With an appropriate pressure level at the 1-2/4-5 holding pressure shift valve (28a) this valve switches over.

2nd gear engaged
After the gear change is complete, the pressure on the end face of the 1-2/4-5 command valve (31a) is reduced via the 1-2 and 4-5 shift solenoid valve (Y3/6y3) and the command valve is pushed back into its original position. Via the 1-2/4-5 holding pressure shift valve (28a) working pressure (p-A) now reaches the front multiple-disc clutch K1) via the 1-2/4-5 command valve (31a). The front multiple-disc brake (B1) is disengaged (depressurized). The spring in the 1-2/4-5 shift pressure shift valve (29a) pushes this into its original position.