GF27.60-S-2001A | Hydraulic transmission control function | 29.8.98 |
MODEL 638 with ENGINE 111.948 /978, 601.970 with CODE (G40) Automatic transmission
MODEL 638 with ENGINE 611.980
with CODE (G40) Automatic transmission
with CODE (MQ4) Engine OM611 DE22 LA (75 KW)
with CODE (MQ5) Engine OM611 DE22 LA (90 KW)
MODEL 638 with ENGINE 111.950 /980
with CODE (G40) Automatic transmission
with CODE (MR7) Engine M111 E20 (95 kW) Euro III
with CODE (MR8) Engine M111 E20 (105 Kw) Euro III
S27.60-0501-09
S27.60-2503-09
1 System pressure valve
2 Pressure regulating valve
3.1 Clutch valve B
3.2 Clutch valve C
3.3 Clutch valve D
3.4 Clutch valve F
4 Clutch valve E
5.1 Holding valve B
5.2 Holding valve C
13 Electric pressure control valve
14 Oil pump
15 Oil filter
17 Converter
18 Converter pressure limiting valve
19 Converter control
20 Oil cooler
5.3 Holding valve D
5.4 Holding valve F
6 Holding valve E
7 Shift valve
8 Safety valve
9 Converter pressure valve
10 Torque converter lock-up clutch valve
11 Lubricating valve
12 Solenoid valve
The system pressure valve (1) determines the general pressure level in the control.
It predominantly supplies the clutches (once the system pressure has been reached).
The cooling and lubricating oil then flows to the converter.
Outside the circuit, the system pressure is switched between two levels depending on the turbine torque.
The Pressure regulating valve (2) reduces the system pressure to the require pressure which supplies the solenoid valves and electric pressure control valves downstream.
This makes its possible to use smaller solenoid valves.
The electric pressure control valves require a constant supply pressure.
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The clutch valves B, C, D, F, (3.1 - 3.4) are in principle follow-up valves of the respective electric pressure control valve.
They are used to supply the required volumetric flow to the corresponding clutch.
Furthermore, they are required for gear-dependent pressure transmission.
The clutch valve E (E) is also a follow-up valve. It has the same purpose as the clutch valves mentioned above.
Clutch valve E is also used to limit pressure for clutch E.
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The holding valves B, C, D, E (5.1 - 5.4) ensure that the appropriate clutch valves are shifted through with a given pressure through the electric pressure control valves so that the clutch pressure rises to the system pressure.
This allows better resolution of the control range of the clutch valves.
Holding valve E (6) ensures that clutch valve E is switched at the maximum permitted value at a certain pressure determined by the electric pressure control valves.
Furthermore, the control range of clutch F is reduced in 2nd gear.
Clutch valve C is supplied with system pressure.
Shift valve (7) acts as an electronic pressure control valve (13) for shifting between 1st and 2nd gear.
If power fails while driving. Clutch C is shifted or held (if already shifted) by the safety valve (8).
Together with clutch E this results in 4th gear.
When the engine is restarted and in the case of emergency operation of the electric transmission control, clutch B is energized by the safety valve.
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Together with clutch E this results in 3rd gear. The safety valve has a lock which is released when the engine is restarted and activated again by the electronic transmission control.
The converter pressure valve (9) supplies the converter with cooling oil when in the open position.
When the torque converter lock-up clutch is closed the supply to the converter is interrupted and the space between the torque converter lock-up clutch and torque converter cover is vented.
The torque converter lock-up clutch valve (1) is in principle the follow-up valve of the electric pressure control valves (13) when MV2 is de-energized.
It is required to bring the volumetric flow to the torque converter lock-up clutch.
Furthermore, the torque converter lock-up clutch carries out the necessary pressure transmission.
The lubricating valve (11) ensures that if the pump flow volume is low, the converter is supplied first with cooling oil.
Furthermore it guarantees the required amounts of cooling and lubrication oil via the bypass duct.
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The hydraulic control module contains 3/2 solenoid valves (12).
They are controlled by the electronic transmission control and have a clear function. The are used to switch valves in the hydraulic transmission control.
The electric pressure control valves (13) convert electric current into proportional hydraulic pressure.
The electric pressure control valves are controlled by the electric transmission control.
They activate the valves belonging to the switch elements.