Joystick control/mini-wheel, function description (hydraulic oil pump alternative

Rexroth)

Mini-wheel or lever steering is a steering option that makes it possible to steer the machine with an electric control.

The relationship between the deflection of the control and that of the wheels can be set to 31 different settings - from linear to extremely progressive. It is also possible to set how steering deflection is to be adapted based on machine speed. This is done via the initiation men- us; see section 8 Control system, group 8.5.1 Initiation.

NOTE

The mini-wheel/lever steering is deactivated if the standard steering wheel is used.

Mini-wheel or lever steering can only be activated at speeds below 3 km/h.

Condition Reference value Reference

Lever steering activated

Voltage signal from switch mini- wheel/joystick control.

Mini-wheel, description page 3 or Joystick, description page 4 Diagnostic menu, see section 8 Control system , group 8.4.11.4 EL-STEERING, menu 2

Steering wheel stationary

No signal from sensor steering wheel movement.

Sensor, steering wheel movement, description page 32 Speed Below 3 km/h (at engagement) -

006404

8 5, 9

11

12

4

13

7

6

10

P LS T CF P LS TP T1 A B

D790-2

D797-O

D790-1 D790-3

1

PP P LS T L R

2

3 D4

D3

D1

D12

C7

Pos Explanation Signal description Reference

1 The joystick switch or mini-wheel switch sends a voltage signal to the cab control unit (D790-1).

On machines with Combi attachment the signal is sent to the cab control unit option (D790-3).

Signal 1, U = 0.5 - 4.5 V Signal 2, U = 0.5 - 4.5 V (mini-wheel only)

Mini-wheel, description page 3 or Joystick, description page 4

D1: Diagnostic menu, see section 8 Control system , group 8.4.11.4 EL-STEERING, menu 1

2 The cab control unit (D790-1) transmits the desired steering deflection on the CAN bus.

On machines with Combi attachment the cab control unit option (D790-3) sends steering deflection on the CAN bus.

Checked by control system; error indicated with error code.

Section 11 Common electrics, group 11.5.3.1 Cab control unit

3 Control unit, frame option (D797-O) sup- plies voltage to the solenoid valve for steering right (Y636R) or the solenoid valve for steering left (Y636L).

I = 350–550 mA Section 11 Common electrics, group 11.5.3.4 Control unit, frame option

D3: Diagnostic menu, see section 8 Control system , group 8.4.11.4 EL-STEERING, menu 4 and 5

VDRF03.02GB Workshop manual DRF 400–450 10 5 Steering – 5.2 Power assisted system

Hydraulic diagram, joystick control 4 The solenoid valve, steering right

(Y636R) or solenoid valve, steering left (Y636l) pressurises the steering slide in the solenoid valve for lever steering or mini-wheel.

- Control valve for lever steering or mini- wheel, description page 28

D4: Diagnostic menu, see section 8 Control system , group 8.4.11.4 EL-STEERING, menu 4 and 5

5 The solenoid valve for lever control or mini-wheel sends a load signal to shuttle valve, steering.

- Control valve for lever steering or mini- wheel, description page 28

6 The shuttle valve selects the strongest load signal to hydraulic oil pump 3 and 4 if hydraulic functions are activated at the same time as the steering wheel is turned.

- Shuttle valve for mini-wheel or lever control, description page 31

7 Hydraulic oil pumps 3 and 4 pump oil from the hydraulic oil tank.

See pressure plate on left frame beam.

Section 10 Common hydraulics, group 10.4.2 Axial piston pump with variable displacement

8 The priority valve prioritises pressure supply to the steering valve over the working hydraulics. The priority valve also transmits a control signal to the hydraulic oil pump 3 and 4.

See pressure plate on left frame beam.

Priority valve page 14

9 The slide changes position and pressurises the steering cylinder.

- Control valve for lever steering or mini- wheel, description page 28

10 The steering cylinder turns the wheels. - Steering cylinder, description page 23 11 The steering wheel is turned and acts on

the steering valve's input shaft.

- Section 9 Frame, body, cab and accesso- ries, group 9.1 Controls and instruments 12 Sensor steering axle sends a voltage

signal to Control unit, cab (D790-1).

U = 24 V Sensor, steering wheel movement, description page 32

D12: Diagnostic menu, see section 8 Con- trol system , group 8.4.11.4 EL-STEERING, menu 3

13 The cab control unit (D790-1) transmits the stop steering on the CAN bus.

Checked by control system; error indicated with error code.

Section 11 Common electrics, group 11.5.3.1 Cab control unit

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