Direct Electro-Hydraulic Coupling Description and Operation

Description

The 4WD ECU processes signals from various sensors and determines current road and driving conditions. The ECU then uses this information to precisely control the 4WD multi-plate clutch and smoothly regulate torque to the rear wheels. 4WD Transfer Mode Selection

1. 1
   AUTO MODE:

   A.	When driving in 4WD AUTO mode, the vehicle operates similarly to conventional all-wheel drive vehicles under normal driving conditions. However, if the system determines that 4WD is needed, engine power is automatically distributed to all four wheels without driver intervention.

   B.	When driving on regular roads and paved surfaces, the vehicle operates in the same way as conventional all-wheel drive vehicles.

2. 2
   LOCK MODE:

   A.	This mode is used for climbing or descending steep slopes, off-road driving, driving on sand and mud roads, etc., to maximize traction.

   B.	This mode automatically begins to disengage at speeds above 30 km/h and switches to 4WD AUTO mode at speeds above 40 km/h (25 mph). If vehicle speed drops below 30 km/h, the transfer mode switches back to 4WD LOCK.

3. 3
   Cruise (Auto Mode) - Power is mainly transmitted to the front wheels.

   

4. 4
   Cornering (Auto Mode) - Adjusts rear wheel power depending on turning radius and cornering speed.

   

5. 5
   Wheel Slip (Auto Mode) - If one or both front wheels lose traction, the system transfers the appropriate amount of power to the rear wheels based on the amount of front wheel slip.

   

6. 6
   Lock Mode - Maximizes off-road performance (active only at speeds below 40 km/h).

   

Electronic Coupling - Four-Wheel Drive Control (Depending on Driving Conditions)

Operation

Electronic clutch

[Inactive]

[Active]

Operation Procedure

1. 1
   The 4WD ECU receives CAN signals from the vehicle sensors.
2. 2
   The 4WD ECU calculates the required rear wheel torque and sends the appropriate control current to the actuator (electronic motor and hydraulic pump).
3. 3
   Hydraulic pressure generated by the actuator moves the piston.
4. 4
   Friction from piston movement engages the clutch.
5. 5
   Power is transmitted to the rear wheels.