FIELD OF INVENTION
This invention relates to an assembly for advancing of fuel injection timing of the diesel engine in cold condition. This is achieved by using the axial movement of helical fuel injection pump gear relative to the crank gear.
PRIOR ART
NOx is one of the emissions that is being regulated from time to time and becoming stringent with every upcoming new emission standard. An effective way to reduce the NOx with mechanical Inline Fuel injection pump is to retard (delay the start of injection) the engine timing to decrease combustion temperature & hence NOx. However, this will result in white smoke & fluttering when engine is started cold. This is due to low combustion temperature & late burning of the fuel. The problem of white smoke & fluttering can be overcome in case the fuel injection timing can be advanced (early injection) for the duration till engine is heated up.
In conventionally known engines, there is no such provision & hence white smoke & fluttering is observed while engine is started cold.
OBJECTS OF THE INVENTION
The primary object of the present invention is to propose an assembly for advancing of fuel injection timing of the diesel engine in cold condition so as to advance the fuel injection timing when the engine is cold & retard the engine after it is warmed up.


Another object of the present invention is to propose an assembly for advancing of fuel injection timing of the diesel engine in cold condition which is efficient.
STATEMENT OF INVENTION
According to this invention, there is provided an assembly for advancing of fuel injection timing of diesel engine in cold condition comprising of a gear and coupling held together by means of spring and dowel wherein thermostat mounted on the gear.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows.: timer unit assembly.
Fig. 2 shows: timer unit in cold condition.
Fig. 3 shows: timer unit- in hot condition.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS;
The present invention discloses an assembly for advancing of fuel injection timing of the diesel engine in cold condition comprising of a

helical FIP gear (1) & coupling (2) which are held together by means of atleast two springs (5) & dowel (4), wherein atleast two thermostats (3) are mounted on said FIP gear (1) through a hole provided in the gear. Thermostats (3) are mounted in such a way that when heated up by hot engine oil splashes, FIP gear is pushed away from coupling against spring force.
During cold conditions, the thermostats are in its contracted position and held together by means of spring force between the gear and coupling. At this position, the timing of the engine is in the advanced mode as shown in fig. 2.
COLD Condition (Fig. 2)
Thermostats are mounted on FI Pump Gear after removing springs & outer body.
FI pump 8s coupling are held together by springs wherein thermostats don't exert any force and just touch coupling face.
Once the engine gets hot after running, the hot lube oil splashes causes the thermostats to expand. The expanding thermostats push the FIP gear apart from the coupling. This lateral movement of the FIP gear causes the relative rotation of the FIP shaft due to its helix. At this position, the timing of the engine remains in the retarded mode as shown in fig. 3.
IN HOT CONDITIONS (FIG. 3)
Thermostats get expanded and exert force on coupling face. Hence, FI pump gear is moved axially away from coupling against spring force by approximately 5mm.
After getting cooled springs again keep FIP gear and coupling together.

When the engine stops & cools down, the thermostats return back to their contacted position and the FIP gear and coupling are pulled back together by the spring force thereby causing the engine timing to get advanced.
Thus, in the present invention, the rotation causes due to the axial movement of the helical FIP gear to utilized for changing the static injection timing as shown in fig. 1. Timing changes through axial motion between the helical gear and coupling relative to the crankshaft.
The static fuel injection timing of the engine is varied by relative rotation of the FIP shaft w.r.t the engine crankshaft.
A relative rotation between two pairs of helical gears takes place upon axial movement of helical gear.
The assembly is used to rotate FIP shaft w.r.t the engine crankshaft by relative rotation of helical FI pump gear w.r.t Idler gear. The relative rotation of FIP gear with reference to Idler gear is achieved by axial movement of FIP gear.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM;
1. An assembly for advancing of fuel injection timing of diesel engine in cold condition comprising of a gear and coupling held together by means of spring and dowel wherein thermostat mounted on the gear.
2. An assembly as claimed in claim 1, wherein said spring, dowel and thermostat are aleast two in number.
3. An assembly as claimed in claim 1 or 2, wherein said thermostats are mounted on Fl pump gear through a hole provided in the gear.
4. An assembly as claimed in any of the preceding claims, wherein the thermostats are mounted in such a way that upon being heated up by hot engine oil splashes, the gear is pushed away from coupling against spring force.
5. An assembly as claimed in any of the preceding claims, wherein during cold conditions, the thermostats are in its contracted position and held together by means of spring force between the gear & coupling, at which position, the timing of the engine is in the advanced mode.
6. An assembly as claimed in any of the preceding claims, wherein when the engine gets hot after running, the hot lube oil splashes causes the thermostats to expand, which push the gear apart from the coupling, in which lateral movement of the gear causes the relative rotation of the shaft, at which position, timing of the engine remains in the retarded mode.


7. An assembly for advancing of fuel injection timing of diesel engine in cold condition substantially as herein described with reference to the accompanying drawings.