1. A unit injector assembly for injecting fuel into a combustion chamber of an engine, the unit injector assembly comprises:
an injector body defining a plunger piston bore and an injection chamber bore therein;
a valve assembly selectively movable between a flow passing position and a flow blocking position;
a plunger assembly having a plunger piston, the plunger piston being disposed in the plunger piston bore of the injector body to define a pumping chamber in the injector body;
an injector tip assembly having a tip check stem, the tip check stem being disposed in the injection chamber bore of the injector body and operative to control the flow of injection fuel from the injection chamber bore;
a first fuel passageway defined in the injector body between the pumping chamber and the injection chamber bore;
a second fuel passageway defined in the injector body between the injection chamber bore and the valve assembly;
a flow restricting fuel passageway defined in the injector body continuously interconnecting one of the pumping chamber and the first fuel passageway with the second fuel passageway.
2. The unit injector assembly of claim 1 wherein the flow restricting fuel passageway includes a connecting passage having an orifice disposed therein.
3. The unit injector assembly of claim 1 wherein the flow restricting fuel passageway interconnects the pumping chamber with the second fuel passageway.
4. The unit injector assembly of claim 1 wherein the injector tip assembly includes a nozzle tip having a valve seat at one end of the injection chamber bore and the tip check stem is disposed in the injection chamber bore and is operative to engage the valve seat.
5. The unit injector assembly of claim 4 wherein a differential area is defined on the tip check stem within the injection chamber bore and operative when in use to urge the tip check stem away from the valve seat.
6. The unit injector assembly of claim 1 in combination with a cam arrangement, the plunger piston of the plunger assembly is in operative engagement with the cam arrangement and is spring biased in a direction towards the cam arrangement.
7. The unit injector assembly of claim 1 in combination with a source of fuel and the valve assembly is operatively connected to the source of fuel.
8. A method for controlling pressure spikes in a unit injector assembly, the method includes the step of:
providing a plunger assembly having a pumping chamber connected to an injector tip assembly through a first fuel passageway;
providing a valve assembly connected to the injector tip assembly through a second fuel passageway; and
providing a flow restricting fuel passageway for continuously connecting one of the pumping chamber and the first fuel passageway with the second fuel passageway.
9. The method of claim 8 wherein in the step of providing a flow restricting fuel passageway, the flow restricting fuel passageway is connected between the pumping chamber and the second fuel passageway.
10. The method of claim 8 wherein in the step of providing a flow restricting fuel passageway includes providing a connecting passageway between the first and second fuel passageways and disposing an orifice therein.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fastener tightening system comprising:
a tightening tool configured to apply torque to a fastener;
a fastener data storage device located on the fastener to store data related to the associated fastener;
at least one component data storage device located on a component receiving the fastener to store data related to a tightening process;
a data sensor configured to sense data stored on the fastener data storage device and the at least one component data storage device; and
a controller configured to regulate operation of the tightening tool based on the sensed data and the sensed parameter.
2. The fastener tightening system of claim 1, wherein the at least one component data storage device is located adjacent to a mating hole receiving the fastener.
3. The fastener tightening system of claim 2, wherein the tightening tool is configured to apply a first torque to the fastener until the axial load acting on the fastener is approximately equal to an initial target axial load, the initial target axial load being determined from the data stored on the at least one component data storage device.
4. The fastener tightening system of claim 3, wherein the tightening tool is configured to apply a subsequent torque to the fastener until the axial load acting on the fastener is approximately equal to a final target axial load, the final target axial load being determined from data stored on the at least one component data storage device.
5. The fastener tightening system of claim 4, wherein the tightening tool is configured to apply the first and subsequent torques to multiple fasteners in a predetermined sequence determined from data stored on the at least one component data storage device.
6. The fastener tightening system of claim 1, wherein the at least one component data storage device is a radio frequency identification device.
7. The fastener tightening system of claim 1, wherein the at least one component data storage device is a coded indicia.
8. The fastener tightening system of claim 1, wherein the fastener data storage device is a radio frequency identification device.
9. The fastener tightening system of claim 1, wherein the fastener data storage device is a coded indicia.
10. A method for tightening a fastener comprising:
reading data stored on a component and the fastener;
applying a first torque to the fastener based on the read data;
adjusting the magnitude of the applied first torque based on the read data;
applying a subsequent torque to the fastener based on the read data; and
adjusting the magnitude of the applied subsequent torque based on the read data.
11. The method of claim 10, further including applying the first and subsequent torques to multiple fasteners in a predetermined sequence based on the read data.
12. The method of claim 11, further including sensing at least one parameter indicative of a first and a subsequent axial load acting on the fastener.
13. The method of claim 12, further including adjusting the magnitude of the applied first torque based on the at least one parameter.
14. The method of claim 13, further including applying the first torque to the fastener until the first axial load acting on the fastener is essentially equivalent to a target initial axial load.
15. The method of claim 14, further including applying the subsequent torque to the fastener until the subsequent axial load acting on the fastener is essentially equivalent to a target final axial load.
16. A fastener tightening system comprising:
a tightening tool configured to apply a torque to a fastener;
a strain sensor configured to sense a parameter of the fastener indicative of an elongation of the fastener;
a stress sensor configured to sense a parameter of the fastener indicative of the magnitude of an applied torque;
a fastener data storage device located on the fastener to store identification data to identify the associated fastener;
at least one component data storage device located on a component receiving the fastener to store data related to a tightening process;
a controller configured to determine a tightening sequence, an initial target axial load, and multiple subsequent target axial loads based on the sensed data, and regulate operation of the tightening tool based on the determined tightening sequence, initial target axial load, and subsequent target axial load.
17. The fastener tightening system of claim 16, wherein the tightening tool is configured to apply a first torque to the fastener until the axial load acting on the fastener is approximately equal to the determined initial target axial load.
18. The fastener tightening system of claim 17, wherein the tightening tool is configured to apply multiple subsequent torques to the fastener until the axial load acting on the fastener is approximately equal to a final target axial load determined from the sensed data.
19. The fastener tightening system of claim 18, wherein the tightening tool is configured to apply the first and subsequent torques to the multiple fasteners in the predetermined sequence.
20. The fastener tightening system of claim 19, wherein the fastener data storage device and at least one component data storage device is one of a radio frequency identification device and a coded indicia.