Caterpillar Inc.

Manas R Satapathy

Scott Richard Schuricht

Thomas G Ausman

Eric M Bram

The present invention relates to engines having multiple hydraulic devices. For instance, in a typical multi-cylinder diesel engine, each cylinder includes an intake valve, an exhaust valve, a fuel injector and an engine brake. It is common for each of these devices to be controlled by an individual actuator. However, engineers have learned that decreasing the number of engine components can increase engine robustness. Therefore, the present invention utilizes a single rotary actuator to control multiple hydraulic devices for an engine cylinder.

Rotary valve for controlling a fuel injector and engine compression release brake actuator and engine using same

A fuel injector performs main fuel injection by raising fuel pressure in a nozzle chamber to lift a check valve member to a fully open position, and performs preinjection or microinjection by operating a solid state motor to lower a check stop so that when fuel pressure in the nozzle chamber is raised the check valve member is limited to lift a much smaller distance.

Variable check stop for micrometering in a fuel injector

A hydraulically actuated fuel injector has an electronically controlled actuator that moves an actuation valve member. The actuator can position the actuation valve member at one position to cause pressurization of fuel in a nozzle chamber for fuel injection, and at another position to hydraulically bias a check to halt fuel injection while maintaining full fuel pressure in the nozzle chamber indefinitely.

Fuel injector with independent control of check valve and fuel pressurization

A hydraulically actuated fuel injector includes an injector body that defines a fuel nozzle outlet and a plurality of passages, including high pressure actuation fluid passages, and low pressure drainage and vent passages. A piston with at least one hydraulic surface is movably disposed between retracted and advanced positions along a stroke distance in a piston bore defined by the injector body. When acted upon by high pressure actuation fluid, the piston, in cooperation with a plunger, advances from its initial retracted position a certain stroke distance before it uncovers and exposes an actuation fluid flow enhancement annulus. Exposure of the piston hydraulic surface(s) to the additional flow capacity provided via the actuation fluid flow enhancement annulus yields higher piston and plunger acceleration rates, resulting in sustained high piston acceleration and a higher peak fuel injection pressure and flow rate.

Hydraulically-actuated fuel injector with enhanced peak injection pressure and stepped top intensifier

An actuation fluid control valve assembly for a hydraulically actuated fuel injector comprises a valve body defining a rotary valve bore and a spool valve bore. An actuator is connected with the valve body. A rotary valve member is rotatably disposed in the rotary valve bore and can be rotated in response to the actuator. A high-pressure fluid line, a spool bottom line, a check control line, and an actuator fluid drain all terminate in the rotary valve bore. At one rotary valve position, both the check control line and the spool bottom line are open to the high-pressure line. Moving the rotary valve from the first position to a second position opens the spool bottom line to the actuator fluid drain while keeping the check control line open to the high-pressure line. Moving the rotary valve from the second position to a third position opens the check control line as well as the spool bottom line to the actuator fluid drain.

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Aurora, IL, United States of America

Manas R Satapathy