Drive control Eco
HCB-DCE (Drive Control Eco)

The DCE advanced drive control system has been developed for vehicles that are expected to be more comfortable. These include municipal machinery, agricultural, forestry and construction machinery and many more. The driver should be relieved of operating the driving functions so that he can concentrate on the actual work. The DCE therefore has all the functions of the basic drive control and also numerous controllers that can be activated as required.

The standard hardware platform for the DCE is the HCB controller. If the DCE is to be integrated into a machine control system, it can easily be ported to another Völkel hardware platform.

The comfort functions in detail

speed control

When speed control is activated using the button, the current driving speed is saved. It serves as a set value for the controller, which acts on the diesel engine, the variable displacement pump and the variable displacement motor. In this way, the speed is controlled in a closed loop and kept constant within the physical limits regardless of the terrain profile. If the accelerator pedal is actuated when the cruise control is active, its value has priority over the set value of the cruise control, provided the set value of the accelerator pedal is greater. If the accelerator pedal is released, the set value for the drive returns to the stored value. The cruise control is deactivated by pressing the button again or by pressing the brake.

Constant pressure regulator

High speeds are achieved with a hydrostatic drive by reducing the hydraulic motor displacement. This measure has the effect of increasing the oil pressure required to accelerate the vehicle. If the machine travels uphill, the pressure may exceed a permitted value depending on the travel speed and the tractive force may drop. The constant pressure regulator increases the torque of the hydraulic motor by increasing the displacement. As a result, the pressure is not built up any further, the machine slows down but the tractive force is maintained.

Brake pressure regulator

The brake pressure regulator ensures continuous deceleration during the entire braking process. The braking process is recorded by pressure sensors, and the adjustment times of the hydraulic pump and hydraulic motor are modified depending on the brake pressure and the hydraulic motor’s displacement volume. The deceleration can be extended in the lower speed range to produce a smooth stop. The brake pressure regulator can also help to prevent unwanted shocks and noises during deceleration.

Diesel overspeed protection

The overspeed governor protects the diesel engine from excessive speed during hydrostatic deceleration (overrun operation). If the diesel speed rises to the set speed limit range, the braking power is reduced by adjusting the hydrostat. The overspeed governor has similar characteristics to the brake pressure governor: If no pressure sensors are present, this governor can be used to generate a similarly continuous deceleration. However, it is then dependent on the supporting torque of the diesel engine.

ECO mode

Modern diesel engines require operation with a high load at the operating point so that the exhaust gas aftertreatment functions efficiently. The DCE therefore enables the machine to start up at a lowered diesel speed and drive at the load edge of the diesel engine. If the drive pump is oversized with regard to the required driving performance, the drive train can be operated at the operating point of best efficiency – the machine also reaches its final speed at a reduced diesel speed. The maximum Power is only called up if the ambient conditions require it.

E1 Type approval

The DCE control hardware platform has E1 type approval so that the machine can be approved for use on European roads.

Extended inputs and outputs

Extended inputs and outputs can be read in via the CAN interface.

Control unit: HCB / Application: DCE (Drive Control Eco)