Cable-coupled by-wire control system
A cable-coupled by-wire control of a vehicle control function traditionally activated by driver manipulation of a pedal is achieved though the agency of a Bowden cable having a first end fastened to the driver pedal, and a second end coupled to a by-wire actuator. The by-wire actuator has a pulley on which the second end of the cable is fastened, an electric motor coupled to the pulley to permit by-wire activation of the vehicle control function by rotation of the pulley in a direction to pull on the pedal with the cable. A relief chamber of the actuator radially outboard of the pulley accommodates slack in the cable within the actuator caused by driver manipulation of the pedal during by-wire activation of the control function.
1. A by-wire control arrangement for a vehicle control function, comprising:
a pedal configured to be depressed by a driver to produce activation of said vehicle control function; and
a by-wire control mechanism including a by-wire actuator, and a Bowden cable having a first end fastened to said pedal and a second end coupled to said by-wire actuator, said by-wire actuator including a pulley on which said second end of said cable is fastened, and an electric motor coupled to said pulley, where said by-wire actuator initiates by-wire activation of said control function by energizing said electric motor to control a rotary position of said pulley, and terminates said by-wire control by de-energizing said electric motor and allowing said pulley to free-wheel with driver depression of said pedal; and
a housing enclosing said pulley, said housing including a cable relief chamber configured so that cable slack due to driver depression of said pedal during activation of said control function causes a portion of said cable to temporarily lift off said pulley and spool into said cable relief chamber before re-seating on said pulley, where said cable relief chamber includes an opening disposed adjacent to a radial periphery of said pulley and receives said portion of said cable when it lifts off said pulley, a narrow pocket radially outboard of said opening dimensioned to receive only a single thickness of said cable, and a tapered lead-in section between said opening and said narrow pocket configured to guide said portion of said cable into said narrow pocket.
2. The by-wire control arrangement of claim 1 , wherein:
said vehicle control function is vehicle braking; and
said pedal is a brake pedal.
3. The by-wire control arrangement of claim 1 , where:
said narrow pocket of said cable relief chamber has a radial perimeter that is gently curved to prevent kinking of said portion of said cable when it spools into said cable relief chamber.