Abstract: A high pressure pump system (14) for use with a hydraulic engine system (10), such as a fuel injection system (10) or a compression release brake system, provides variable delivery of pressurized fluid using sleeve metering principles. The relative position of metering sleeves (56) with respect to pumping pistons (32) is controlled electro-hydraulically by a control circuit (60, 160). The control circuit (60, 160) receives pressurized fluid from the pump delivery gallery (50) or another high pressure area (50, 52) and, using a pressure reducer (64, 164), reduces the operating pressure within the control circuit (60, 160) to a substantially constant pressure lower than the pump output pressure. Lower operating pressure within the control circuit (60, 160) improves the manufacturability of the control circuit components and helps to achieve better control of the pump output.

Abstract: A method of controlling a hydraulic system is preferably applied to common rail fuel injection systems. The problem in these systems is to control pressure in the common rail while at the same time maintaining the fluid supply to the rail in a way that precisely meets the dynamically changing consumption demands on the hydraulic system. In order to control the hydraulic system, the present invention contemplates the combination of a standard feedback controller with observer models of the various hardware items that make up the hydraulic system. Using this strategy, the system can generally be thought of as controlling fluid supply in an open loop type fashion based upon the consumption rates estimated by the various observer models, and utilizing a conventional feedback controller to make the slight pump adjustments needed to control pressure and to correct for any errors between the actual hardware performance and that predicted by the observer models.

Abstract: A high pressure pump system (14) for use with a hydraulic engine system (10), such as a fuel injection system (10) or a compression release brake system, provides variable delivery of pressurized fluid using sleeve metering principles. The relative position of metering sleeves (56) with respect to pumping pistons (32) is controlled electro-hydraulically by a control circuit (60, 160). The control circuit (60, 160) receives pressurized fluid from the pump delivery gallery (50) or another high pressure area (50, 52) and, using a pressure reducer (64, 164), reduces the operating pressure within the control circuit (60, 160) to a substantially constant pressure lower than the pump output pressure. Lower operating pressure within the control circuit (60, 160) improves the manufacturability of the control circuit components and helps to achieve better control of the pump output.

Abstract: A method of controlling a hydraulic system is preferably applied to common rail fuel injection systems. The problem in these systems is to control pressure in the common rail while at the same time maintaining the fluid supply to the rail in a way that precisely meets the dynamically changing consumption demands on the hydraulic system. In order to control the hydraulic system, the present invention contemplates the combination of a standard feedback controller with observer models of the various hardware items that make up the hydraulic system. Using this strategy, the system can generally be thought of as controlling fluid supply in an open loop type fashion based upon the consumption rates estimated by the various observer models, and utilizing a conventional feedback controller to make the slight pump adjustments needed to control pressure and to correct for any errors between the actual hardware performance and that predicted by the observer models.

Abstract: A method for adjusting the on-time of each hydraulically-actuated fuel injector within a hydraulically-actuated fuel injection system is disclosed. At least two spray tests are performed on the fuel-injector prior to its installation in a fuel injection system. The fuel injector is marked with a bar-code capable of representing these results. Immediately prior to installing the fuel injector into the fuel injection system, the bar-code on the fuel injector is scanned and the results of the spray tests are stored in a memory unit accessible to the electronic control module. These results are used to develop a unique electronic trim solution for the fuel injector. The performance of the fuel injector is then adjusted using the electronic trim solution to enable the performance of the fuel injector to approach that of a nominal injector.

Abstract: A fuel injector includes an injector body that defines a pressure relief passage with one end opening into a trapped volume, and a fuel pressurization chamber in fluid communication with a nozzle outlet. A needle valve member is positioned in the injector body and moveable between an inject position in which the fuel pressurization chamber is open to the nozzle outlet, and a closed position in which the nozzle outlet is blocked. The needle valve member has a closing hydraulic surface exposed to fluid pressure in the trapped volume. A pressure relief valve is positioned in the pressure relief passage, and has a valve member with an opening surface exposed to fluid pressure in the trapped volume, and a closing surface exposed to fluid pressure in the fuel pressurization chamber.

Abstract: A method for adjusting the on-time of each hydraulically-actuated fuel injector within a hydraulically-actuated fuel injection system is disclosed. At least two spray tests are performed on the fuel injector prior to its installation in a fuel injection system. The fuel injector is marked with a bar-code capable of representing these results. Immediately prior to installing the fuel injector into the fuel injection system, the bar-code on the fuel injector is scanned and the results of the spray tests are stored in a memory unit accessible to the electronic control module. These results are used to develop a unique electronic trim solution for the fuel injector. The performance of the fuel injector is then adjusted using the electronic trim solution to enable the performance of the fuel injector to approach that of a nominal injector.

Abstract: A fuel injector includes an injector body that defines a low pressure space, a trapped volume and a fuel pressurization chamber in fluid communication with a nozzle outlet. A needle valve member is positioned in the injector body and moveable between an inject position in which the fuel pressurization chamber is opened to the nozzle outlet, and a closed position in which the nozzle outlet is blocked to the fuel pressurization chamber. The needle valve member includes a lifting hydraulic surface exposed to fluid pressure in the fuel pressurization chamber, and a closing hydraulic surface exposed to fluid pressure in the trapped volume. At least one of the injector body and the needle valve member define a pressure decay passage extending between the trapped volume and the low pressure space.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines an actuation fluid cavity, a piston bore, a plunger bore, a nozzle chamber and a nozzle outlet that opens to the nozzle chamber. A piston is slidably received in the piston bore and moveable between an upper position and a lower position. A plunger is slidably positioned in the plunger bore and moveable between a retracted position and an advanced position. A portion of the plunger and the plunger bore define a fuel pressurization chamber that opens to the nozzle chamber. The injector body further defines a nozzle supply passage extending between the fuel pressurization chamber and the nozzle chamber, a spill passage extending between the nozzle supply passage and the nozzle chamber, and a fuel return passage opening into the nozzle chamber.