FIELD OF THE INVENTION:-
The present invention is related to fixtures and devices used during the engine production system. More particularly, the present invention is related to a fixture for pressing overflow pipe in engine production system.
BACKGROUND OF THE INVENTION:-
In any automobile diesel engine there is an arrangement for collecting excess fuel supplied to injectors and sending it back to fuel tank. There is a pipe with branches connected to individual injectors and the other end of the pipe is connected to fuel pipe. There are various designs of overflow pipes. Some have banjo bolt connection with injectors while others have locking clips. In some specific designs (mHawk) engines there is "O" ring on overflow pipe connectors which seals overflow pipe with injector. In order to squeeze "O" ring into injector vertical force is to be applied on overflow pipe connector.
The conventional methods of overflow pipe pressing are like (i) manually pressing overflow pipe connectors with the help of hammer, and (ii) auto pressing of OFP connectors with dollies attached to individual pneumatic cylinders. But these conventional methods of pressing overflow pipe carries some drawback like damage to the part, not safe during the operation, not ergonomically suitable for the operator, takes more operation time and manufacturing cost is high. Further, the auto pressing of OFP connectors with dollies attached to individual pneumatic cylinder leads to cause engine mis-alignment with dollies often due to pallet stopper position variation. One of the major reason for overflow pipe breakage is that the pressing dolly axis is not in line with overflow pipe connector axis as pallet stopper position cannot be fixed.
Therefore, to address these drawbacks in the conventional system and to provide safe, ergonomic, efficient method of overflow pipe pressing, the present invention is presented wherein the specially developed fixture align the pressing dolly with overflow pipe connector axis always irrespective of pallet stopper position.
OBJECTIVES OF THE PRESENT INVENTION:-
The main objective of the present invention is to provide safe, efficient, ergonomic, economic and easy to use method of overflow pipe pressing.

Another objective of the present invention is to provide a unique fixture for pressing the overflow pipe during the engine manufacturing operation.
STATEMENT OF INVENTION:
Accordingly invention provides a fixture for pressing overflow pipe in engine production system comprises a base plate (1) forming the housing for mounting a number of pressing dollies with a guiding liner; a bias spring provided to each of the said dollies; a number of resting legs (2) provided symmetrically at distant to the said base plate for resting the complete fixture on cam cover mounting bolt heads; two numbers of locating pins (3&4) provided to the said base plate with location on the said base plate matching with the dowel holes of the cam cover such that arrangement ensures zero alignment of pressing dollies (6) with.overflow pipe connectors inserted in injectors of engine
BRIEF DESCRIPTION OF THE FIGURES:-
Figure 1 shows the unique fixture as per the present invention for pressing the overflow pipe during engine manufacturing operation.
Figure 2 shows perspective view of the fixture as per the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
In the present invention the main principle is of keeping a plate on engine located in cam cover dowel holes with spring loaded dollies mounted on the plate itself. This design always ensure dolly axis alignment with OFP connector axis irrespective of pallet position.
Referring to Figure 1, the fixture of the present invention for pressing the overflow pipe comprises of base plate, plurality of resting legs, locating pins and pressing dollies to form the complete fixture assembly. The base plate (1) acts as the housing for pressing dollies. The four resting legs (2) helps for resting the complete fixture on cam cover mounting bolt heads. The locating pins (3&4) locates fixture repeatedly in the same position on every engine. The four pressing dollies (6)helps for pressing overflow pipe connectors in injectors.

The fixture gets accurately located on cam cover by means of two locating pins (3&4). The two locating pins enter dowel holes on cam cover This arrangement ensures zero alignment of pressing dollies (6) with overflow pipe connectors inserted in injectors of engine. These pressing dollies (6) are mounted in the base plate (1) of the fixture. There is spring (9) which retracts the pressing dollies to home position as soon as pressing load on dollies is released. There are liners (5) fixed on base plate (1) for guiding the pressing dollies (6). The said locating pins and resting legs are pastened to the said base with lock nuts. The elements (10 & 11) are lock nuts for pins.
For working of the fixture for pressing overflow pipe in engine production system following steps in a sequential manner are followed.
- Lift fixture from hanger manually by both hands.
Keep it on cam cover mounting bolt heads by locating in dowel holes of cam
cover.
Press operating switches on machine by both hands. This will bring
pneumatically operated dollies of the machine down gradually pressing spring
loaded fixture dollies down.
Fixture dollies will in turn press overflow pipe connectors inside injectors.
Pressing action will continue till OFP connectors bottom butts against injector top
face.
- Pneumatic machine dollies will retract up wards after a fixed dwell time. Lift fixture from engine & keep it back on hanger.
- Inspect overflow pipe pressing operation and put check mark on all overflow pipe connectors.
THE INVENTION PROVIDES FOLLOWING ADVANTAGES:-
- One of the chronic defect of overflow pipe breakage during manufacturing of specific engines (m-hawk engine) got totally eliminated.
- The manufacturing cost of the fixture is very low thus leading the economic solution to the problem.
- The invention carries very high horizontal deployment potential wherever the engine has vertical injector design.
- Axis of pressing dollies of fixture is always aligned with OFP connector axis. This results in proper pressing of OFP connector preventing overflow pipe breakage.

- Process robustness has been achieved ensuring EVERY TIME RIGHT operation.
Engine remains clean as earlier diesel spillage used to happen due to pipe breakage.
The invention provides low cost in-house manufacturable solution.

We claim:
1. A fixture for pressing overflow pipe in engine production system comprises a base plate (1) forming the housing for mounting a number of pressing dollies with a guiding liner; a bias spring provided to each of the said dollies; a number of resting legs (2) provided symmetrically at distant to the said base plate for resting the complete fixture on cam cover mounting bolt heads; two numbers of locating pins (3&4) provided to the said base plate with location on the said base plate matching with the dowel holes of the cam cover such that arrangement ensures zero alignment of pressing dollies (6) with overflow pipe connectors inserted in injectors of engine.
2. The fixture as claimed in claim 1 wherein the said pressing dollies (6) four numbers.
3. The fixture as claimed in claims 1 and 2 wherein the said resting legs (2) are four numbers.
4. The fixture as claimed in claims 1 to 3 wherein the said locating pins and resting legs fastened to the said base plate with lock nuts.