FIELD OF INVENTION:-
The present invention is related to jigs and fixtures used during the assembly of vehicle components. More particularly, the present invention is related to a device used during the assembly of clutch for the concentric fitment of subcomponents of clutch assembly.
BACKGROUND OF THE PRESENT INVENTION:-
Clutch judder is one of the main clutch related defect in the vehicles and it's root cause is during the assembly of the clutch assembly on the vehicle assembly line. The occurrence of this defect is high and this defect has high severity. Clutch judder defect has following ill effects on vehicle performance.
- Vibration on clutch pedal, resulting in high NVH level.
- Early & uneven clutch wear out.
- Poor vehicle ride-ability
- Engine performance low, less power output, mileage is affected.
- Overall vehicle performance is hampered.
- Clutch engagement point is increased.
The conventional method of clutch assembly is shown in Figure 1. The fitment of clutch sub-components is done in clutch engagement condition. It is the condition where the pressure plate is pressed against the clutch disc, making a full butting between engine flywheel & clutch disc. Initially clutch disc is mounted face to face against the flywheel. A splined shaft is used to align the centers. The clutch cover is then placed over the clutch disc, & it is bolted with 6 bolts on flywheel using an electric multi spindle nut runner.
This method has following disadvantages:
- Concentricity w.r.t. engine flywheel can't be controlled.

- Clutch disc is in engagement with the flywheel, i.e. the disc is under load exerted by pressure plate during the fitment. Causing un-even load on the disc.
To overcome the above issues, a device as described in the following specification is developed.
OBJECTIVES OF THE PRESENT INVENTION:-
The main object of the present invention is to provide a device for concentric fitment of clutch sub-components.
Another objective of the present invention is to provide a device that applies uniform pressure on the fingers of the diaphragm spring to achieve the clutch -disengagement condition.
Another objective of the present invention is to provide a device that holds the flywheel, clutch disc, clutch cover in one axis i.e. the centre of the crankshaft during the assembly of the clutch.
STATEMENT OF INVENTION:-
Accordingly invention provides a device for concentric fitment of clutch subcomponents comprises a C shape holding two arms LH and RH(A) with a threaded hub fixed at centre adapted to be fitted to back side of the fly wheel with holding sub-assembly component in concentric manner on spilt shaft; a pressing metallic ring (C), having four number of pins at equidistant along the circumference on face of the ring mounted on the said hub; an threaded adapter screwed on the said threaded hub so as to move said pressing ring forward; the guiding holes provided to the said c-shape bracket for the said pins of the pressing ring; a stopper bracket (D).provided to the said c-shape for enclosing said adopter assembly on the said hub.

DESCRIPTION OF THE FIGURES:-
Figure 1 shows the conventional method of fitting clutch and its sub-components (prior art).
Figure 2 shows a device for concentric fitment of clutch sub-components as per the present invention.
Figure 3 shows a device for concentric fitment of clutch sub-components as per the present invention in working condition.
DESCRIPTION OF THE INVENTION;-
The conventional method uses diaphragm spring clutch system. The clutch cover assembly comprising a cover, a pressure plate, a diaphragm spring acting between the cover and pressure plate to urge the pressure plate outwardly of the cover, and drive straps in the form of leaf springs attached to the cover and pressure plate to retract the latter into the cover when urging by the diaphragm spring is relieved. The diaphragm spring controls the amount of pressure applied on the pressure plate and clutch disc, and seats them against the flywheel.
Any misalignment between the clutch & flywheel assembly results in clutch judder, phenomena of shaking the vehicle in fore- and-aft direction. It affects the clutch life drastically. Thus it is very important to maintain the concentricity of the engine flywheel, clutch disc, clutch cover i.e. same as the centre of crankshaft. To maintain the correct concentricity, the clutch disc, cover plate fitment should be completely stressed free. There should not be any pre-load on the clutch disc. The stress free condition of the clutch is only achieved in clutch disengagement condition.
The Invention is based upon fitment of clutch sub components in clutch disengagement condition. The invention is related withholding the flywheel, clutch disc, clutch cover co-axially and the uniform pressing of the clutch cover diaphragm spring. The clutch cover then is bolted on the flywheel. The

diaphragm spring pressing achieved is within specified tolerance limit, 14+3 mm. The invention is based on achieving the clutch disengagement condition (achieved by complete pressing of the clutch pedal on vehicle) i.e. moving the pressure plate away from the clutch disc, thus isolating the clutch disc from the engine fly wheel. The diaphragm spring controls the amount of pressure applied on the pressure plate and clutch disc, and seats them against the flywheel.
The device is related to concentric fitment of clutch sub components in clutch disengagement condition. It comprises of a metallic Jig which has two holding arms with a threaded adapter on its centre; splined shaft which holds the clutch disc & Teflon disc in concentric position; and teflon disc which is made up of Teflon material, specially made to apply uniform load & presses the diaphragm spring evenly.
The main sub components of the clutch assembly are clutch disc and clutch cover. These two are assembled on the engine flywheel, in such a way that they remain concentric with the engine crank shaft. The said device applies uniform pressure on the fingers of the diaphragm spring to achieve the clutch disengagement condition. It also holds the flywheel, clutch disc, clutch cover in one axis i.e. the centre of the crankshaft. Once these two conditions are achieved, the clutch cover is then bolted on the engine flywheel.
The uniqueness of this invention is to achieve the clutch disengagement condition wherein the concentricity is also maintained. It is the same condition when you press the clutch pedal before you shift the gear. The clutch disengagement is achieved by uniform pressing of the diaphragm spring fingers. The uniform pressing of the diaphragm spring pushes the spring fingers inwards, causing the leaf springs to pull the pressure plate away from the clutch disc, hence isolating the disc from the engine fly wheel. This stress free condition before the fitment of clutch disc & clutch cover assembly benefits to achieve the concentric fitment.
The device is a "C" shaped jig, which is used to assemble the clutch subcomponents on the engine flywheel in clutch disengagement condition. The

invention relates to a holding structure. It is a two armed structure with a threaded hub welded at its centre. The LH & RH arms are designed to hold the back side of engine flywheel. The ends of the LH & RH arms are further bent to form a claw to lock the JIG against the back side of the engine fly wheel, A metallic ring with four welded pins, functions as the pressing ring, exerting the pressure on diaphragm spring. The guiding holes are made in the said arms for moving said pins. The four welded pins apply uniform pressure on a Teflon disc which further exerts the same pressure on the diaphragm spring fingers. A threaded adapter with an Allen-hex drive, which screws over the hub in forward & reverse direction with the help of a battery nut runner. A stopper bracket prevents the falling of the adapter on the ground.
As shown in Fig. 2, a device has a holding arm (A), threaded adapter (B), pressing ring (C) and stopper bracket (D). The holding arm has a threaded hub welded at the center and the pressing ring has the four pins welded.
During the operation, as shown in Fig. 3, a device is mounted along the flywheel diameter. It holds a splined shaft, a clutch disc, Teflon disc& pressure plate in between. The arms are located from the back side of the flywheel & the adapter moves to-n-fro on the threaded hub. Then torque is applied on the adapter (30Nm). It moves adapter forward and applies pressure on Teflon disc. After achieving the specified torque value, the Teflon disc presses the pressure plate diaphragm spring 15 mm inwards. Finally the pressure plate mounting 6 bolts are tightened on the engine flywheel.
The advantages achieved by this device are as under:
- Elimination of clutch judder defect.
- Internal customer complaint made to ZERO.
- Cash out flow saving of Rs30 lacs by in house development of the Jig.
- Cash out flow saving of Rs 60 lacs by eliminating the use of electric six spindle nut runner, the clutch cover fitment is possible with regular pneumatic nut runner.
- Improved Operator & team morale.

- The said device is easy to use, Compact, handy & light weight. -
- It gives positive locking against flywheel.
- Accuracy in controlling the concentricity and maintenance free.

WE CLAIM:-
1. A device for concentric fitment of clutch sub-components comprises a C shape holding two arms LH and RH(A) with a threaded hub fixed at centre adapted to be fitted to back side of the fly wheel with holding sub-assembly component in concentric manner on spilt shaft; a pressing metallic ring (C), having four number of pins at equidistant along the circumference on face of the ring mounted on the said hub; an threaded adapter screwed on the said threaded hub so as to move said pressing ring forward; the guiding holes provided to the said c-shape bracket for the said pins of the pressing ring; a stopper bracket (D).provided to the said c-shape for enclosing said adopter assembly on the said hub.
2. The device for concentric fitment of clutch sub-components as claimed in claim 1 wherein the said arms LH and RH ends bent to form a claw to lock the JIG against the back side of the engine fly wheel.
3. The device for concentric fitment of clutch sub-components as claimed in claims 1 and 2 wherein the said adapter with an Allen-hex drive, which screws over the hub in forward & reverse direction with the help of a battery nut runner.