摘要:
A method of fabricating a piezo actuator is disclosed. The method includes forcing a blank against a mold to form a cylindrical casing having an open end and a closed end and rotating the cylindrical casing. The method also includes urging a die having a plurality of equally spaced protrusions into a surface of the cylindrical casing to form bellows in the cylindrical casing. The method further includes positioning a piezo element within the cylindrical casing.
摘要:
A metallic fuel system component includes an internal surface and an external surface. The metallic fuel system component is made by inducing compressive residual stress in only a portion of the internal surface of the metallic fuel system component by transmitting a laser shock wave through the metallic fuel system component from the external surface to the internal surface.
摘要:
Pressurized injector actuation fluid, such as oil or fuel, is supplied to high pressure common rail by a fixed displacement fluid pump. Variable delivery from the pump is achieved by an improved sleeve metering approach. The sleeve surrounds the reciprocating piston and is manipulated to control venting of pumped fluid through vent ports in the piston. The sleeve is moved by preferably being the armature of a solenoid assembly. The varying of current to the solenoid coil alters the axial position of the sleeve relative to the piston to vary the effective pumping stroke of the piston.
摘要:
An actuator for a fuel injector is disclosed. The actuator has a piezo element, a casing, and at least one end plate. The casing is fabricated through a deep draw process, has bellows, and is configured to house the piezo element. The at least one end plate is hermetically connected to an end portion of the casing.
摘要:
A control system for a fuel injector is disclosed. The control system has a nozzle member with at least one orifice, and a needle check valve. The needle check valve is recipratingly disposed to open and close the at least one orifice. The control system also has a control chamber located at the base end of the needle check valve, and a control valve movable to selectively drain and fill the control chamber. The control system further has an injector body, a first piston located within the injector body, and a second piston located within the injector body. The first piston is operatively connected to the control valve to move the control valve. The second piston is located a distance from the first piston to form a coupling chamber. The control system additionally has a partial-ball check valve associated with the coupling chamber to selectively replenish the coupling chamber.
摘要:
A hydraulic system, such as a fuel injection system, includes a fixed displacement pump with at least one pump piston. A sleeve surrounds each pump piston and provides the method by which fluid displaced by the pumping stroke of the pump piston is directed either to a high pressure area in the pump or a low pressure area. The sleeves are a portion of an electro-hydraulic controller that includes a mechanical bias to bias the pump to a high output position when a pressure differential between the outlet area and the inlet area is relatively low, such as at cold start up. This aspect facilitates priming of the system. In addition, the controller includes a biasing hydraulic surface in opposition to the mechanical biaser that serves to bias the pump to its low output position when the pressure differential between the outlet area and the inlet area is relatively high. This aspect prevents over pressurization in the event that electric current to the controller is disrupted.
摘要:
A hydraulically-actuated system includes a fix displacement variable delivery pump with a plurality of parallel disposed pistons that reciprocate in a pump housing the defines a high pressure portion and a low pressure area. A control device is attached to the pump housing and moveable between a first position in which the pistons displace fluid into the high pressure portion and a second position in which pistons spill fluid back to the low pressure area. The control device includes an electrically driven linear motion device, a linkage and a plurality of sleeves, one being disposed on each piston. Linear movement of the control device in turn causes linear movement of the sleeves. The position of the sleeves in turn determines the amount of output of the pump.
摘要:
A displacement pump includes a rotatable drive shaft; a low-pressure hydraulic fluid reservoir; at least one piston containing a piston cavity; and a drive plate connected with the drive shaft. The drive plate includes an inlet passage and a fill slot. The fill slot is fluidly connected with the low pressure hydraulic fluid reservoir via the inlet passage. The drive plate is rotatable about the drive shaft such that as the drive plate rotates, the piston cavity is intermittently fluidly connected with the fill slot.
摘要:
In one case of hydraulically actuated fuel injection systems, the engine lubricating oil is utilized as the hydraulic medium to actuate the individual fuel injectors. In a typical example, these fuel injectors are fluidly connected to a common rail that is maintained a relatively high pressure when the engine is running. When the engine is turned off, the oil in the common rail both drops in pressure and in temperature. As this occurs, a thermal contraction effect takes place. This lost volume is made up by an oil replenishing reservoir that captures some of the engine lubricating oil that finds its way into the chamber defined by the engine head and valve cover. A check valve is positioned between the oil replenishing reservoir and the common rail so that the two are isolated from one another while the engine is running. At free start, shorter engine cranking times are encountered because the hydraulically actuated fuel injection system can come up to full pressure substantially faster.
摘要:
A hydraulically-actuated system includes a fixed displacement pump with at least one piston that reciprocates in a pump housing that defines a high pressure area and a low pressure area. A control valve is attached to the pump housing and moveable between a first position in which the piston displaces fluid in a first proportion between the high pressure area and the low pressure area, and a second position in which the piston displaces fluid in a second proportion between the high pressure area and the low pressure area. At least one hydraulically-actuated device is connected to the high pressure area of the pump. A source of low pressure fluid is connected to the low pressure area of the pump. An electronic control module is in communication with and capable of controlling the position of the control valve.