Direct injection assembly for a dual injection system of a motor vehicle

A dual fuel injection system for pressurizing a volume of fuel for an internal combustion engine of a motor vehicle, the dual fuel injection system comprising:

• a camshaft for rotating about a camshaft axis;
• a port injection assembly for delivering a first volume of fuel at a first pressure;
• and
• a direct injection assembly for delivering a second volume of fuel at a second pressure that is above the first pressure, wherein the direct injection assembly comprises:
• a follower comprising:
• an input piston operably engaged with the camshaft and moving between first and second input positions along a first follower axis, in response to the camshaft rotating about the camshaft axis;
• an output piston movable between first and second output positions along a second follower axis, with the first and second follower axes being spaced laterally apart from one another, and the input and output pistons do not overlap one another along a vertical direction that is parallel to the first and second follower axes;
• and
• a coupler movable between a deactivated state and an activated state where the coupler holds the input piston and the output piston in fixed positions relative to one another while moving along a corresponding one of the first and second follower axes for transmitting, using the coupler, a force from the input piston to the output piston;
• and
• a pump having a plunger engaged with the output piston of the follower and movable from a first plunger position to a second plunger position where the plunger pressurizes the volume of fuel, in response to the plunger receiving the force from the output piston of the follower;
• and
• a controller coupled to the direct injection assembly and configured to move the coupler to the activated state where the direct injection assembly pressurizes the second volume of fuel to the second pressure, and the controller is further coupled to the port injection assembly and configured to actuate the port injection assembly to pressurize the first volume of fuel to the first pressure.

A method for operating a direct injection assembly, with the direct injection assembly including a camshaft, a pump, a controller, and a follower having input and output pistons and a coupler, the method comprising the steps of:

• rotating the camshaft about a camshaft axis;
• moving the input piston of the follower between first and second input positions along a first follower axis, in response to the camshaft rotating about the camshaft axis;
• moving the coupler between deactivated and activated states;
• holding, using the coupler, the input piston and the output piston in fixed positions relative to one another, in response to the coupler being disposed in the activated state;
• transmitting, using the coupler, a force from the input piston to the output piston, in response to the input and output pistons being held in fixed positions relative to one another;
• moving the output piston between first and second output positions along a second follower axis, with the first and second follower axes being spaced laterally apart from one another, such that the input and output pistons do not overlap one another along a vertical direction that is parallel to the first and second follower axes, in response to the coupler being disposed in the activated state while the camshaft is rotating about the camshaft axis;
• moving a plunger of the pump from a first plunger position to a second plunger position where the plunger pressurizes a first volume of fuel, in response to the output piston moving from the first output position to the second output position.