Apr 152013
 

These are integrated to the manual transmission with no special modifications to the clutch and the internal part of the gear, only the gearbox is changed to permit the fastening of the hydraulic actuators that control the clutch and the gear engagement selection. The clutch pedal has been eliminated, therefore for a breakaway start only the accelerator pedal is used. By means of an electro-hydraulic group, the electronic control unit manages gear engagement both in semi-automatic and automatic mode.

Semiautomatic, or manual, the driver makes a direct gear change by activating the lever on the centre console or through the buttons on the steering wheel.

Automatic, also called “city”, in this configuration it is the system that makes the decision as to when to change gear. The advantages are: the driver does not have to use the clutch pedal and the gear shift lever, but is not deprived of the pleasure of driving that comes from direct control of transmission.

The CFC 208 is set to

  • acquire the signals coming from the different sensors
  • interface with the engine control unit (Motronic M7.3.1)
  • control the hydraulic system
  • manage the information display and buzzer

The CFC 208F input signals

  • rpm, (from rev. counter through Bosch Motronic control unit M7.3.1)
  • gearbox input revs
  • car speed (information to CAN line)
  • clutch actuator position
  • selector actuator position
  • engagement actuator position
  • key in travel position
  • door switch status driver side
  • brake pedal switch status
  • electro-hydraulic group oil pressure
  • CAN line signal (position of accelerator pedal, engine torque, water temperature, etc.)
  • gear change request from buttons or lever
  • +50 engine ignition.

The interface with C.C.M. M7.3.1 is managed on the CAN line. To control the hydraulic actuation sub-system the CFC 208F has

  • 1 output to adjust the proportional flow-rate solenoid valve for clutch control
  • 2 outputs to adjust the proportional pressure solenoid valve for gear engagement control
  • 2 outputs to control the on/off solenoid valves to control selection
  • 1 output to control the electric pump
  • 1 output to control the ignition relay

The CFC 208F also gives the start enable.

Selespeed Alfa Romeo 147 functional diagram

Selespeed Alfa Romeo 147 functional diagram

Description

  1. Gear selection lever switch
  2. Engine rpm sensor (CAN line from CCM)
  3. Car speed signal on CAN line from ABS
  4. Gear shift buttons
  5. Brake pedal switch
  6. Oil pressure sensor
  7. Door switch driver side
  8. City button
  9. Gearbox input revs sensor
  10. Clutch position sensor
  11. Gear selection position sensor
  12. Gear engagement position sensor
  13. DVE motorised throttle case ( CAN line from CCM)
  14. Accelerator pedal potentiometer (CAN line from CCM)
  15. Pressure proportional solenoid valves ( 2)
  16. On-off solenoid valves (2)
  17. Flow rate proportional solenoid valve
  18. Electric pump
  19. Buzzer
  20. On-board panel
  21. Diagnostics socket
  22. Start enable relay
 Posted by at 10:19 pm
Mar 242013
 

The concept of the Selespeed transmission system for Alfa Romeo 147 follows the aim already developed on the Alfa Romeo 156 from which it originates. The aim is to improve performance of the manual gearbox transmission components. To avoid that the driver has to check the clutch pedal and the gear control lever but at the same time ensuring the driving pleasure that comes from direct control of transmission. To improve driving safety by a direct control that foresees the errors of the driver and prevents an incorrect control of the transmission system. Offer the driver a more advanced car interface? It should be remembered that the system essentially consists of a mechanical transmission, with dry monodisk clutch and synchronised mechanical gear, moved by hydraulic power steering. As previously with the Alfa Romeo 156, neither the clutch nor the gearbox is changed to install the hydraulic actuators that control the stroke of the clutch and the gear engagement and selection.

An electronic control unit manages a complex functioning logic that permits the use of the gearbox:

  • in “semi-automatic” conditions, where the driver controls the gear engagement by the lever on the tunnel or with two push-buttons.
  • In “automatic” mode, called “City” that assigns the decision to change gear to the electronic system. The clutch pedal has been eliminated , the traditional “H” gear lever of manual transmission has been replaced by a specific “Joystick” lever and two “UP-DOWN” buttons on the steering wheel.
Selespeed overview

General overview with the main components of the Selespeed system

Description

  1. Control unit
  2. Electro-hydraulic group with electric pump
  3. Engine control unit (Bosch M7.3.1)
  4. Motorised throttle case (D.V.E.)
  5. Gear selection display
  6. Down-gear button (Down)
  7. Up-gear button (Up)
  8. “City” mode button
  9. Gear control selection lever
  10. Accelerator
  11. Switch on brake pedal

Power steering system

Essentially consists of an electro-hydraulic group (2) mounted directly onto the gearbox. By means of two pistons it manages the gear selection and engagement. The two pistons are controlled by a group of solenoid valves, to which an electric pump and an accumulator supply the required hydraulic power.
An electronic control unit (1) having identified the requirements of the driver from the lever (9) or from buttons (6) and (7) autonomously manages the gear change, directly controlling clutch, gearbox and engine torque. During the gear shift the engine control is subordinated to the gear control.

The gear – engine interface

Considerably improves the system performance and relieves the driver of any need to synchronise the clutch-accelerator movements during the gear change, that can be effected with the accelerator always fully pressed down. Furthermore, the system inhibits incorrect requests to change gear and avoids engine stalling. In terms of aid to driving it also ensures: immediate availability of first gear when the vehicle stops; automatic downward gear change n the case of a strong deceleration. The gear engaged is shown on a display built into the panel on board (central display), whereas indications of faults or driving conditions critical for the vehicle or for transmission components are indicated directly on the display highlighting the text: Selespeed system fault, and, on the right of the panel the gearbox fault symbol is shown.

Selespeed system components

Selespeed system components

Description

  1. Gear selection lever
  2. “City” button
  3. Selespeed control unit (assembled in passenger compartment under the dashboard, passenger side)
  4. Gear selection buttons on steering wheel
  5. Electro-hydraulic group
  6. Electric pump
  7. Hydraulic oil pump
  8. Speed sensor on gearbox
  9. Gear selection display
  10. Fault warning light
 Posted by at 12:09 pm