Shifting, function

B26.60-6629-09

B26.18-0002-79

1 Coupling mouth cylinder

2 Selection cylinder

3 Fuse

4.03 4-circuit protective valve

5.01 Air reservoir

B40 Clutch sensor

B41 Engaged gear switch

G12 Gearbox outlet speed sensor unit

S29 Selector lever

U10 Easy-shift control electronic unit

U11 Central of solenoid valves

U12 Amplifier module of the speed sender unit

U13 Cutting pressure electronic module of the easy-shift system

a Pneumatic system

Operation

When moving the lever (S29) into the gear engagement position, an electrical signal is sent to the electronic unit (U10). At this moment, this module (U10) sends an electrical signal to the valve center (U11) which activates, pneumatically, the selection cylinders (2) and the coupling mouth (1) performing the coupling of the selected gear.

After the coupling, the cutting pressure electronic module (U13) makes a 4-second temporization and blocks the air passage to the cylinders (1 and 2). This is done to avoid the fork to push the sliding sleeves and, as a consequence, damaging the synchronized rings. The start of the temporization is done after receiving the clutch pedal sensor signal (applied when the driver steps on the clutch pedal to change the gear) and the signal of the engaged gear switch (B41).

The easy-shift has a protection system against the gearbox over-rotation. This system uses a speed sensor unit (G12) to indicate the speed of the vehicle to the electronic control unit (U10). The signal sent by the speed sensor unit (G12) is amplified by the module (U12) and processed by the electronic control unit (U10). If the vehicle speed is over 35 Km/h, this unit (U10) sends a signal to the gear selector lever (S29) so that a lever lock-out is done, through a electro pneumatic valve that unables the driver to engage the first and second gears. Likewise, when exceeding the speed of 60 Km/h, the electronic control unit (U10) sends a signal to the gear selector lever (S29) and the engagement from the first to the forth gear is blocked.

Characteristics

- The electro pneumatic gear change system (Easy-Shift) has the purpose to provide more comfort to the driver. In addition, the system also protects the gearbox against sudden gear reduction changes.

- On this system, there is no mechanical linkage between the gear selector lever and the gearbox. The gear change is performed by two pneumatic cylinders on the top of the gearbox, electronically controlled.