FIELD OF THE INVENTION:-
The present invention is related to testing device used in manufacturing processes. More particularly, the present invention is related to self plugging pressure leakage testing plug used in testing the conduits and opening of engine assembly for pressure leakage.
BACKGROUND OF THE INVENTION:-
In the manufacture of engines on the assembly line, it is often essential that the conduits, passages and openings of the engine assembly be pressure tested before the assembly is dispatched from the engine assembly line. In pressure leakage testing, it is necessary to apply a testing pressure several times larger than the normally intended to be sure that the sufficient safety factor is ensured.
For leakage prevention in pressure leakage testing, a variety of solutions are available in the public domain. Conventionally available principles for plugging and pressure testing available in the knowledge domain are Threaded plugging, Tube plugging with clamp / band clamping, Press fit plugging, Quick release plugging with ball locking, Pasting plugging with application of liquid or semisolid sealants, and Face plugging with plate & clamping with bolts.
Referring to Figure 1a (prior art) the plugging is done by threading portion where the sealing is achieved by putting some gap filling media like teflon tape. Figure 1b (prior art) shows the rubber 0 ring under collar for sealing where the sealing is achieved by threading locking against acting pressure. Referring to Figure 2 (prior art) sealing is achieved by clamping pressure by diff clamps as shown in figure against acting pressure.
Referring to Figure 3 (prior art), pressure leakage is achieved by press fit plugging wherein the plug is installed on pipe opening on component with interference to achieve sealing where the sealing is achieved by rubber interference against pressure. Referring to Figure 4 (prior art), pressure leakage test Is done by Quick release plugging with ball locking wherein the plug is

installed on pipe opening on component the pulling mechanism in QRC gives the sealing effect against rubber seal and the sealing is achieved by pulling / spring force against pressure. Referring to Figure 5, pressure leakage is done by Face plugging with plate & clamping with bolts wherein the plug is installed on opening on component with two bolts wherein the plug having rubber face & metallic back with bolts for clamping.
All these prior art solutions are limited in their application as the plug locking is complex and involves complex mechanism for coupling. These requires high amount of time for its installation and un-installation and require a special tool for its installation; susceptible to early wear and tear and involves high cost. Further, these uses spring force for sealing. To address these drawbacks of the prior art, present invention of self plugging pressure leakage plug is proposed.
OBJECTIVES OF THE PRESENT INVENTION:-
The main objective of the present invention is to provide self plugging pressure leakage testing plug.
Another objective of the present invention is to provide self plugging pressure leakage testing plug which is readily and quickly installed over the object to be tested for pressure leakage.
Another objective of the present invention is to provide self plugging pressure leakage testing plug which utilizes the pressure being applied inside the object to effect the seal in pressure leakage test.
Still another objective of the present invention is to provide self plugging pressure leakage testing plug which is more or less universal in its application and can be used in sealing conduits, tubing, openings and passages in the engine assembly.
Still further object of the present invention is to provide self plugging pressure leakage testing plug which is economically comfortable and reduces fatigue of

the operator in the production cycle thereby improving the productivity and cycle time.
BRIEF DESCRIPTION OF FIGURES:-
The above mentioned objectives and advantages of the present invention will become apparent from the figures and the specifications relative thereto, wherein
Figure 1 shows the conventional practice of threaded plug used in pressure leakage test.
Figure 2 shows tube plugging with clamp / band clamping as the conventional practice.
Figure 3 shows press fit plugging system conventionally practiced.
Figure 4 shows prior art practice of Quick release plugging with ball locking for pressure leakage testing.
Figure 5 shows prior art practice of Face plugging with plate & clamping with bolts for pressure leakage testing methodology.
Figure 6 shows the engine assembly with the conduits and passages where the self plugging plug of the present invention is installed.
Figure 7 shows the exploded view of the self plugging plug of the present invention and the conduit of the engine assembly to be tested for pressure leakage.
Figure 8 shows the perspective view of the self plugging plug of the present invention.
Figure 9 shows the cross sectional view of the self plugging plug mounted on the condult tested Tor pressure leakage.

Figure 10 shows the exploded view of the rubber seal used in the self plugging plug of the present invention.
Figure 11 shows the assembly diagram of the self plugging plug of the present invention.
Figure 12 shows the flow path of the fluid inside the self plugging plug of the invention and how the self sealing is achieved.
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
In automotive industries the close circuits, particularly in engine assembly, to be tested for pressure leakage are Water circuit, Oil circuit (pressurised), Oil circuit (drain), Fuel circuit, etc. These needs to check for leakages to get the final product assured for different joints forming the above circuits. The generally used principles in leakage testing are pressurised air leakage testing method and Vacuum leakage testing method.
Referring to Figures 8 and 9, the self plugging plug of the present invention comprises of main body, rubber seal and a lock nut. The lock nut and main body of the plug are made from metal. The lock has the threads throughout its inner periphery. The rubber seal sits inside the main body and forms a cavity between the main body and the flexible wall of the rubber seal. The rubber seal is locked inside the main body with the help of locking nut.
To mount the self plugging plug over the object to be tested for pressure leakage, first the locking nut is inserted over the object, then the rubber seal is placed followed by main body. The locking nut locks the rubber seal inside the main body creating the cavity between the main body and the wall of the rubber seal. When the pressurized air is passed through the object to be tested for leakage, the test pressure is diverted in close cavity formed by solid container & flexible inner wall. The test pressure is acting on component made to act on flexible inner side which resulted in clamping pressure.

THE ADVANTAGES ACHIEVED BY THIS INVENTION ARE AS UNDER:-
- The plug of the present invention is manufactured with one of the most
conventional machines.
Very simple with respect to manufacturing
- It doesn't involve anchoring action
- The component involved are very easy to manufacture
- No assistance of any force like special mechanical element like spring
- No positive lock for position retention
- No complex element like ball, cam etc. No cam locking
- No tight fit for seal.
- Working on frictional force.
- Assembly line work content reduction,
- Ergonomics improved
- Maintenance / running cost reduced.
- Aesthetic improved

WE CLAIM:-
1. Self plugging pressure leakage testing plug comprising of a main body, rubber seal and a lock nut wherein the lock has the threads throughout its inner periphery; the rubber seal sits inside the main body and forms a cavity between the main body and the flexible wall of the rubber seal; the said rubber seal is locked inside the main body with the help of locking nut.
2. Self plugging pressure leakage testing plug as claimed in claim 1, wherein no assistance of any force like special mechanical element like spring is required and no positive lock for position retention is required.
3. Self plugging pressure leakage testing plug as claimed in claim 1, wherein the said plug works on frictional force thereby reducing the work content on the assembly line.
4. Self plugging pressure leakage testing plug as claimed in claim 1, follows the following steps for its mounting over the object to be tested for pressure leakage
first the locking nut is inserted over the object,
then the rubber seal is placed followed by main body,
the locking nut locks the rubber seal inside the main body creating
the cavity between the main body and the wall of the rubber seal,
when the pressurized air is passed through the object to be tested
for leakage, the test pressure is diverted in close cavity formed by
solid container & flexible inner wall,
the test pressure is acting on component made to act on flexible
inner side which resulted in clamping pressure.