What we claim is:
1. A method of selecting an optimal combination of a direct injection engine and a direct injecting fuel injector from a plurality of direct injection engines and direct fuel injectors, each of the engines and fuel injectors having characteristics selected from a plurality of engine and fuel injector characteristics, the method comprising:
(a) generating at least one map that relates engine load, engine speed and injector tip temperature for an operating range of the engine, the combination operating at a generally stochiometric air-fuel mixture;
(b) determining changes in fuel flow through the injector when the combination is operated at one or more selected points of the at least one map over a selected period of time;
(c) generating at least one engine-characteristic map as a function of:
(i) changes in fuel flow obtained while performing (b);
(ii) injector tip temperature obtained while performing (a);
(d) performing (a) to (c) for at least another combination; and
(e) selecting one combination that has the least amount of changes in fuel flow being indicated on the at least one engine-characteristic map generated in (c).
2. The method as claimed in claim 1, wherein the generating further comprises selecting another combination from the plurality of engine and fuel injector characteristics, and generating another map whenever the injector tip temperatures over the operating range of the another combination are greater than a predetermined value.
3. The method as claimed in claim 2, wherein the determining further comprises maintaining the engine load constant at the at least one selected speed point.
4. The method as claimed in claim 3, wherein the maintaining further comprises maintaining air flow to the pre-selected engine substantially constant.
5. The method as claimed in claim 4, wherein the determining further comprises operating the engine in a closed-loop mode, and monitoring a pulsewidth of the fuel injector required to maintain the closed-loop mode.
6. The method as claimed in claim 3, wherein the determining further comprises selecting a plurality of speed points over a plurality of engine loads representative of an entire range of injector tip temperatures from the at least one map and monitoring changes in fuel flow.
7. The method as claimed in claim 3, wherein the determining further comprises maintaining a substantially constant inlet air temperature, a substantially constant fuel temperature, and a substantially constant engine coolant temperature over the at least one operating range.
8. The method of claim 1, wherein the generating of the at least one map further comprises changing to a different combination by changing at least one characteristic from the plurality of engine and fuel injector characteristics, the at least one characteristic comprising an axial position of the injector tip relative to a cylinder head of an engine.
9. The method of claim 1, wherein the generating of the at least one map further comprises changing to a different combination by changing at least one characteristic from the plurality of different engine and fuel injector characteristics, the at least one characteristic comprising a different fuel composition of the fuel.
10. The method of claim 1, wherein the generating of the at least one map further comprises changing to another combination by changing at least one characteristic from the plurality of different engine and fuel injector characteristic, the at least one characteristic comprising one of a coating on the injector valve seat, valve seat geometry and fuel composition.
11. A method of selecting an optimal combination of a direct injection engine and a direct injecting fuel injector from a plurality of direct injection engines and direct fuel injectors, each of the engines and fuel injectors having characteristics selected from a plurality of engine and fuel injector characteristics, the method comprising:
(a) generating at least one map that relates engine load, engine speed and injector tip temperature for an operating range of the engine, the combination operating at a generally stochiometric air-fuel mixture;
(b) evaluating the at least one map to determine whether the at least one combination includes a tendency to form injector tip combustion deposits; and
(c) generating at least one engine characteristic map when the evaluating indicates a tendency of the combination to form combustion deposits on the injector, the engine characteristic map being generated as a function of
(i) changes in fuel flow by determining changes in fuel flow through the injector when the combination is operated at one or more selected points of the at least one map over a selected period of time, and
(ii) injector tip temperatures obtained from (a).
12. The method of claim 11, wherein the generating of the at least one map further comprises changing at least one characteristic from the plurality of different engine and fuel injector characteristics whenever at least one injector tip temperature over the operating range is greater than a preset value.
13. The method as claimed in claim 11, wherein the determining further comprises maintaining the engine load substantially constant at the at least one selected speed point.
14. The method as claimed in claim 13, wherein the maintaining further comprises maintaining air flow to the engine substantially constant.
15. The method as claimed in claim 14, wherein the determining further comprises operating the engine in a closed-loop mode, and monitoring a pulsewidth of the fuel injector required to maintain the closed-loop mode.
16. The method as claimed in claim 11, wherein the determining further comprises selecting a plurality of speed points of the at least one map that are representative of an entire range of injector tip temperatures for at least one combination.
17. The method as claimed in claim 11, wherein the generating of the at least one map at predetermined engine operating conditions comprises maintaining a substantially constant inlet air temperature, a substantially constant fuel temperature, and a substantially constant engine coolant temperature over the at least one operating range.
18. The method of claim 16, wherein the evaluating comprises determining whether at least two or more points on the map, each point corresponding to a temperature greater than a predetermined temperature range.
19. The method of claim 16, wherein the evaluating comprises determining whether at least two or more points on the map are between approximately 120 degrees Celsius and 140 degrees Celsius.
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 thread repair tool comprising:
a) a support comprising a head and a leg depending from the head, the leg having an outer surface and an inner surface;
b) a removable cutter having a top surface proximate to the head, an inner surface against the inner surface of the leg, and an outer surface provided with cutting threads for tapping; and
c) a holder holding the cutter against the leg.
2. The tool of claim 1 wherein the holder comprises a bushing.
3. The tool of claim 1 wherein the holder comprises a clamp.
4. The tool of claim 1 wherein a portion of the support is threaded for engagement with an adjustment nut.
5. The tool of claim 1 comprising at least one spacer between the top surface of the cutter and the head.
6. The tool of claim 1 wherein the head is adapted for rotating the tool.
7. The tool of claim 1 wherein the outer surface of the leg and the outer surface of the cutter define a cutting diameter and both inner surfaces are tapered so that moving the cutter away from the head decreases the cutting diameter.
8. The tool of claim 7 comprising at least one spacer between the top surface of the cutter and the head.
9. The tool of claim 1 wherein the outer surface of the leg and the outer surface of the cutter define a cutting diameter, and both inner surfaces are tapered so that movement of the cutter relative to the head changes the cutting diameter.
10. The tool of claim 7 comprising a rotatable nut causing movement of the cutter relative to the head.
11. A thread repair tool comprising:
a) a support having a head and a core depending from the head, the core having an outer surface;
b) at least one removable guide proximate to the head, the guide having an outer surface and an inner surface against the core;
c) a removable cutter having a top surface proximate to the head, an inner surface against the core, and an outer surface provided with cutting threads for tapping; and
d) a holder holding the cutter and the guide against the core.
12. The tool of claim 11 comprising at least two removable guides proximate to the head, both legs having an outer surface and an inner surface against the core.
13. The tool of claim 11 wherein the outer surface of the cutter and the outer surface of the guide define a cutting diameter, and both inner surfaces and the core outer surface are tapered so that movement of the cutter and guide relative to the head alters the cutting diameter.
14. The tool of claim 13 comprising at least one spacer spacing the cutter away from the head.
15. The tool of claim 14 wherein the spacer also spaces the guide away from the head.
16. A thread repair tool comprising:
a) a support having an outer wall;
b) a cutter having an inner surface proximate to the circumferential wall and an outer cutting surface distal from the outer wall of the support;
c) means for adjusting the distance between the cutter and the outer wall of the support;
d) at least one guide proximate to the outer wall of the support; and
e) means for adjusting the distance between the support outer wall and the guide.
17. The tool of claim 16 wherein the cutter and the guide are at opposite sides of the support wall.
18. The tool of claim 17 wherein the guide has a cutting surface.
19. The tool of claim 17 comprising a plurality of guides without a cutting edge.
20. A method for repairing threads of hole comprising the steps of:
a) selecting the tool of claim 7;
b) moving the cutter relative to the head for adjusting the cutting diameter to a selected cutting diameter;
c) tightening the holder for holding the cutter at the selected cutting diameter; and
d) after step (c), rotating the tool in the hole for repairing the threads.