FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
(SEE SECTION 10; RULE 13)
"SELF POSITIONING APPARATUS FOR HYDRAULIC LASH ADJUSTER IN ENGINE ASSEMBLY AND METHOD THEREOF"
MAHINDRA & MAHINDRA LIMITED A COMPANY REGISTERED UNDER THE PROVISIONS OF COMPANIES ACT, 1956 HAVING ADDRESS AT R & D CENTER, AUTOMOTIVE SECTOR, 89, M.I.D.C, SATPUR, NASHIK - 422 007, MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THE INVENTION AND MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
Present invention is related to an apparatus used during engine assembly process. More particularly the present invention is related to self positioning apparatus for hydraulic lash adjuster used during the assembly of dual overhead camshaft type diesel engines and method of adjusting the hydraulic lash thereby.
BACKGROUND OF THE PRESENT INVENTION:-
The Performance of the engine is governed by the combustion characteristics of the engine. For the optimum performance of the any diesel engines, the opening and closing of the valve at desired time is important .The opening and closing of the valves are based on the camshaft lobe angle. The said mechanism comprises of camshaft, cylinder valve and hydraulic lash adjuster. After the start of the engines the drive mechanism which is connected through sprocket and chain start rotating, based on the rotation of the camshaft of the engine and position of the camshaft the hydraulic lash adjuster transmit the position of the camshaft to valve.
Hydraulic Lash Adjuster is the part of Valve train which transmits position to open and close of the inlet valve and exhaust valve based on the camshaft lobe position during running of the engine. To correct valve opening and closing the one edge is rested on the valve tip of engines as shown in Figure 1 wherein the assembly comprises of hydraulic lash adjuster (1), valve (2), valve spring (3) and roller (4). The other end of Hydraulic Lash adjuster is inside the oil gallery of the cylinder head to adjust the gaps between valve and tip of hydraulic lash adjuster hydraulically. The roller (4) as shown in Figure 1 is in contact with the camshaft.
Conventionally during engine assembly process, after dropping of the cylinder head on the block, the state operator picks up the Hydraulic Lash Adjuster and is manually placed on the valve tip. Other end of the Hydraulic lash adjuster is put on the oil gallery port of the cylinder head. Before assembly of the Hydraulic lash adjuster on the valve tip, grease is applied to ensure Hydraulic lash adjuster

is properly placed on the valve. This whole process of assembly is manual on the engine assembly lines of dual overhead camshaft type diesel engines.
This manual process of hydraulic lash adjuster has certain drawback like the assembly of the Hydraulic lash adjuster on the cylinder head is completely blind operation for the Hydraulic lash adjuster of opposite side for the station operator and therefore it requires special skill set of the operators for assembly. Further, it demands 100% inspection after the assembly of hydraulic lash adjuster and for this activity one additional dedicated operator per shift is required. Thus, this process leads to rejection and rework of the engine assembly due to improper assembly of the Hydraulic lash adjuster on the valve tip as the improper placement / alignment of hydraulic lash adjuster generates unwanted sound during the operation of the engine.
The conventional methods and related prior art did not disclose any specific full proof solution to this problem. Therefore, it was decided to develop an apparatus for hydraulic lash adjustment and the present invention discloses the said apparatus and method thereof for hydraulic lash adjustment.
OBJECTIVES OF THE PRESENT INVENTION:-
The main object of the present invention is to provide a novel and unique apparatus for hydraulic lash adjustment and method of using the same for hydraulic lash adjustment during the assembly of dual overhead camshaft type diesel engines.
Another object of the present invention is to provide a novel and unique apparatus for hydraulic lash adjustment and method of using the same for hydraulic lash adjustment wherein the blind nature of the operation for the stage operator is eliminated.
Another object of the present invention is to provide a novel and unique apparatus for hydraulic lash adjustment and method of using the same for

hydraulic lash adjustment wherein a dedicated skilled operator is eliminated during the assembly of dual overhead camshaft type diesel engines.
Yet another object of the present invention is to provide a novel and unique apparatus for hydraulic lash adjustment and method of using the same for hydraulic lash adjustment wherein the assembly of dual overhead camshaft type diesel engines is full proof and rejection and rework of the assembled engines is totally eliminated.
STATEMENT OF 1NVENTION:-
Accordingly the invention provides a self positioning apparatus for hydraulic lash adjuster in engine assembly comprises a longitudinal member with top flat surface with flat ends having in between throughout the length downwardly extended ribs so as to provided at lower side a longitudinal slot formed by the said ribs and a number vertical slot, both side, matching with the bridges in the cylinder head and number of pair of lash slots .adjacent to said bridge slot, both sides, matching with valve lash positions in such a way that when the said self positioning apparatus placed on the cylinder head with said ends resting on the cylinder head faces the profile of the said ribbings (6) fits in the bridges of the cylinder head and guides the hydraulic lash adjuster till the valve tip of cylinder head.
BRIEF DESCRIPTION OF THE FIGURES:-
The objectives and advantages of the present invention will be more clearly understood from the following description of the invention taken in conjunction with the accompanying drawings, wherein,
Figure 1 shows the assembly of hydraulic lash adjuster and valve train in the dual overhead camshaft type diesel engines.

Figure 2 shows the exploded view of the cylinder head for where the self positioning apparatus for adjusting hydraulic lash is mounted.
Figure 3 shows the self positioning apparatus in accordance with the present invention for adjusting hydraulic lash in the diesel engines.
Figure 4 shows the plan of cylinder head with self positioning apparatus mounted in the cylinder head in accordance with the present invention.
Figure 5 shows the cross sectional view of the cylinder head with self positioning apparatus mounted in the cylinder head taken at F-F in Figure 4.
Figure 6 shows the exploded view of ribbing profile of the self positioning apparatus that meshes within the bridges of cylinder head in accordance with the present invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION:-
In accordance with the present invention, self positioning apparatus for hydraulic lash adjustment as shown in Figure 3 has a unique ribbing profile matching with the bridges of the cylinder head. The said self positioning apparatus is made of Aluminum casting as per the shape of Hydraulic lash adjuster as shown in Figure 3. The side edges (10) of the self positioning apparatus are rested on the flat surface (11 and 12) of the cylinder head as shown in Figure 2. A plurality of ribs (6) of the self positioning apparatus (5) is guided in the bridges (13) of the cylinder head. The unique shaped profile of the ribbings (6) of the self positioning apparatus (5) guides the hydraulic lash adjuster till the valve tip of cylinder head. The clearances between the ribbings of the self positioning apparatus and bridges of the cylinder head are as per the design and based on the dimensions of Hydraulic lash adjuster, cylinder head of the specific dual overhead camshaft type diesel engine.

In figure 3 in the apparatus the slot for lash guiding is marked as 'L' and the slot for bridge engaging is engine head bridge portion marked by 'G'
With reference to the method of using self positioning apparatus for hydraulic lash adjustment comprises the steps of gently dropping the cylinder head on the cylinder block of the engine followed by the placement of self positioning apparatus on the cylinder head on faces (11 and 12) of the cylinder head. The said self positioning apparatus (5) is then guided in the bridge of cylinder head as shown in Figures 4 and 5.
After the assembly of self positioning apparatus, Hydraulic lash adjuster assembly is run. The Hydraulic lash adjuster is then guided through the self positioning apparatus and rests on the valve tip. After proper assembly of Hydraulic lash adjuster, the self positioning apparatus is then taken out from the cylinder head.
The advantages derived out of this invention are as under:
- The self positioning apparatus of the invention totally deskills the operation and therefore no set of skilled operators is required to perform the assembly operation.
- Requirement of a dedicated skilled operator per shift is totally eliminated.
- 1S and 2S of the stage is improved due to elimination of grease.
- Zero defect in the engine was recorded after implementation of the self positioning tool on the assembly line, thus totally eliminating the rework and repair activity of the engine assembly.
- Greasing activity, conventionally followed, is completely eliminated.
- It is a low cost solution and locally manufacturable with no wear and tear of the LSA over the period of time/usage.
- Easily customizable to similar category of engines, that is the engines wherein dual overhead camshaft is used, wherein depending upon layout of the cylinder head the profile of the ribbing of the self positioning apparatus will vary accordingly.

It is to be understood that the present invention is not limited in its application to the details of the construction and to the arrangements of the components as mentioned in the above description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, the terminologies used herein are for the purpose of description and should not be regarded as limiting.

WE CLAIM:-
1. A self positioning apparatus for hydraulic lash adjuster in engine assembly comprises a longitudinal member with top flat surface with flat ends having in between throughout the length downwardly extended ribs so as to provided at lower side a longitudinal slot formed by the said ribs and a number vertical slot, both side, matching with the bridges in the cylinder head and number of pair of lash slots, adjacent to said bridge slot, both sides, matching with valve lash positions in such a way that when the said self positioning apparatus placed on the cylinder head with said ends resting on the cylinder head faces the profile of the said ribbings (6) fits in the bridges of the cylinder head and guides the hydraulic lash adjuster till the valve tip of cylinder head.
2. The self positioning apparatus as claimed in claim 1 wherein the said the clearances between the ribbings of the self positioning apparatus and bridges of the cylinder head are as per the design and based on the dimensions of Hydraulic lash adjuster, cylinder head of the specific dual overhead camshaft type diesel engine.
3. The self positioning apparatus as claimed in claims 1 and 2 wherein the said apparatus is made of Aluminum casting as per the shape of Hydraulic lash adjuster.
4. A method of hydraulic lash adjustment in engine assembly using self positioning apparatus comprises the steps:
a. gently dropping the cylinder head on the cylinder block of the engine;
b. followed by the placement of self positioning apparatus on the
cylinder head on faces (11 and 12) of the cylinder head;
c. the said self positioning apparatus (5) is then guided in the bridge of
cylinder head;
d. after the assembly of self positioning apparatus, Hydraulic lash
adjuster assembly is run and the Hydraulic lash adjuster is then

guided through the self positioning apparatus and rests on the valve tip; e. after proper assembly of Hydraulic lash adjuster, the self positioning apparatus is then taken out from the cylinder head.