AU695382B2

AU695382B2 - Engine ignition timing device

Info

Publication number: AU695382B2
Application number: AU40510/95A
Authority: AU
Inventors: Pierre Deguara
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-19
Filing date: 1995-12-19
Publication date: 1998-08-13
Anticipated expiration: 2015-12-19
Also published as: AU4051095A

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Application Number: Lodged: Class Int. Class Complete Specification Lodged: Accepted:' Published: Priority Related Art: APPLICANT'S REF: COMPLETE-ASSOCIATED- WITH-PROVISIONAL PN 0101 Applicant(s): PIERRE DEGUARA 46 Mclntosh Road Altona North VICTORIA 3025 Actual Inventor(s): PIERRE DEGUARA Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: ENGINE IGNITION TIMING DEVICE Our Ref: IRN 394795 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): t JMN C:\WINWORDUENNY\WORKXPNOIOI.DOC* r ENGINE IGNITION TIMING DEVICE a.

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d C The present invention relates generally to ignition timing of spark ignition engines, and more particularly to a device for providing a reference indication of crankshaft positioning for setting and maintaining timing of spark ignition. The device is applicable to automotive spark ignition piston engines and it will be hereinafter described with respect to that exemplary application. It is to be appreciated, however, that this invention is not limited to that particular application.

As will be understood by persons skilled in the art of automotive engine design, manufacture and maintenance, an harmonic balancer (also called a vibration damper) is a heavy wheel mounted in rubber, or like resilient material, for absorbing and controlling torsional vibrations transmitted through the engine crankshaft.

The basic construction of a typical harmonic balancer is a heavy outer ring, known as an inertia ring, attached to an inner hub via a friction fit over a rubber ring located between the inertia ring and the hub. The hub is usually keyed to the crankshaft. In some cases the harmonic balancer also incorporates the crankshaft pulley.

20 In many cases, spark ignition timing marks for automotive piston engines are provided on an harmonic balancer inertia ring. This, however, has the disadvantage that during the life of the engine the harmonic balancer, which is designed to absorb torsional vibrations of the crankshaft, experiences slippage in the rubber ring friction fit causing the timing marks on the inertia ring to move out of their proper position and, as a result, no longer provide an accurate reference indication of top dead centre for the no. 1 piston.

It is an object of the present invention to provide a device for marking ignition timing for engines which ordinarily have the spark ignition timing marks located on the harmonic balancer.

It is further an object of the present invention to provide an ignition timing device for attachment to an engine crankshaft which substantially overcomes the

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DG C:\WNWORDDEULILAHSPECIXENGINE.DOC ii i D9~ bL 2 problem of inertia ring slippage and consequential inaccuracy of harmonic balancer timing marks.

According to one broad aspect, the present invention provides a device for providing a reference indication of crankshaft positioning for setting and maintaining ignition timing of spark ignition engines. The device includes a mounting portion and a carrying portion. The mounting portion is adapted for rigid attachment to the crankshaft for rotation therewith, and, in use, extends radially of a rotational axis of the engine crankshaft. The carrying portion is for carrying indicia means by which the positioning of the crankshaft can be determined.

Importantly, the device of the invention is adapted to assume the task of indicating spark ignition timing from an harmonic balancer.

In at least one preferred embodiment of this invention, the timing device is Sr' configured so as to be mountable in face-to-face relation with an harmonic balancer. The timing device, in use, preferably projects radially beyond an outer 4I" 15 periphery of the harmonic balancer and may be configured so as to, in use, 4Ctc extend over an outer peripheral edge of the harmonic balancer.

In at least one preferred embodiment of the invention, the timing device is ,arranged to substantially house the harmonic balancer. The timing device may therefore have a shell-like configuration, such as, for example, ;ie form of a shallow dish, for substantially surrounding the harmonic balancer.

In at least one embodiment of this invention, the mounting portion is formed from plate material and is configured to extend substantially perpendicular to the f rotational axis of the crankshaft. In a preferred form, plate material forming the mounting portion is relatively thin. It is also preferred that the plate material is substantially rigid. The plate material is also preferably relatively light-weight. The mounting portion is desirably symmetrical about the rotational axis of the crankshaft and, in one preferred form, is disc-shaped.

In at least one embodiment of this invention, the mounting portion includes holes for effecting rigid attachment of the timing device to the crankshaft by means of bolts. The timing device may be attached to a hub of the crankshaft by bolts passing through the holes and being received in corresponding tappings in the hub.

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In at least one embodiment of this invention, the carrying portion, in use, is located radially distal from the rotational axis of the crankshaft. Accordingly, the carrying portion is preferably provided at a periphery of the mounting portion.

Preferably, the carrying portion extends around the entire periphery of the mounting portion. Furthermore, the carrying portion is preferably formed integrally with the mounting portion. In one preferred form of the invention, the carrying portion, in use, extends axially of the rotational axis of the crankshaft. Thus, the carrying portion may be in the form of a peripheral flange member which extends transverse the plane of the mounting portion. In an alternative embodiment of this invention, the carrying portion, in use, extends radially of the rotational axis of the crankshaft as an extension of the mounting portion.

t* ~The indicia means comprises markings to be made on the carrying portion.

#tilt The indicia means may be formed in, or alternatively, cut from the material of the a ,t carrying portion. The indicia means may also be in the form of markings which tto 15 may be adhesively applied to the carrying portion.

By mounting the device of this invention to an engine crankshaft adjacent the harmonic balancer, the device is able to assume the task previously performed by the balancer of indicating engine timing. The !resent invention therefore provides a simple and effective means of io,/er ,oming the uncertainties and problems associated with inaccurate timing marks on harmonic balancers caused by inertia ring slippage. The harmonic balaricer, meanwhile, remains free to 4: continue functioning to dampen torsional vibrations in the shaft. The device of the invention is simple and economical to manufacture and may be easily fitted to existing automotive spark ignition piston engines.

In another aspect, therefore, the present invention also contemplates the provision of an harmonic balancer assembly which incorporates a device as described above. That is, this invention contemplates an harmonic balancer assembly for mounting on an engine crankshaft which includes a hub for rigid attachment to the crankshaft for rotation therewith, an harmonic balancer inertia ring mounted in a resilient material such as rubber for vibration relative to the hub, and a device for providing a reference indication of crankshaft positioning as described above for rigid attachment to the hub.

.iA Q DC C:\IEFCUDJLPECI'NNDOC ~f F Throughout the description and claims of this specification the word "comprise" and variations of that word such as "comprises" and "comprising", are not intended to exclude other additives or components or integers.

The above and other features, aspects and advantages of this invention will become more readily apparent from the following detailed description of preferred embodiments of this invention with reference to the accompanying drawings, in which: Fig. 1 is an exploded view of a typical harmonic balancer and a timing device according to a preferred embodiment of this invention.

Fig. 2 is a sectional side view of the harmonic balancer and timing device shown in Fig. 1 assembled to an in-use orientation.

r ",Fig. 3 is a sectional side view of a timing device according to an alternative ,embodiment of the invention assembled to an in-use orientation with a different it type of harmonic balancer, i.e. the harmonic balancer also incorporates a pulley.

15 Referring to Fig. 1 and Fig. 2 of the drawings, the harmonic balancer B #tit includes a relatively massive inertia ring I which is friction-fitted onto the hub H of the engine crankshaft S by means of an interference fit over the resilient, 1% i t' elastomeric or rubber ring R disposed between the hub H and the inertia ring I.

The inertia ring typically bears markings M for use in determining engine ignition 20 timing.

4 Fig. 1 and Fig. 2 of the drawings show a device 1 for providing a reference

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indication of crankshaft positioning for setting and maintaining or adjusting ignition timing of spark ignition engines. The timing device 1 includes a mounting portion 2 comprising a disc-shaped member 3 formed from relatively thin, substantially rigid plate material for mounting the device 1 adjacent the harmonic balancer B.

The disc-shaped member 3 of mounting portion 2 is provided with holes 4 for effecting a rigid attachment of the timing device 1 to the crankshaft S by means of bolts 5. The bolts 5 may pass through the holes 4 in the mounting portion and may screw into corresponding threaded holes or tappings T in the hub H. The disc-shaped mounting portion 2 may also include a central opening or hole 6 for location of the timing device 1 about a corresponding raised edge E in a central region of the crankshaft hub H.

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The timing device 1 of Fig. 1 and Fig. 2 also includes a carrying portion 7 for carrying indicia means or markings by which to obtain a reference indication of crankshaft position. The carrying portion 7 comprises a flange member 8 extending from a periphery of the disc-shaped member 3 in a direction axially of the rotational axis of the crankshaft S. That is, the flange member 8 extends substantially transverse a plane of the disc-shaped member 3. The flange member 8 of the carrying portion 7 is formed integrally with the mounting portion 2 from the same relatively thin, substantially rigid plate material. Indicia means 9 may be carried on the flange member 8 of the carrying portion 7. The indicia means 9 comprises marks which may be formed with, or alternatively cut from the material of the flange member 8. The marks of indicia means 9 may, as a further alternative, also be adhesively applied to the flange member 8.

The timing device 1 is configured such that the disc-shaped mounting portion 2 projects radially beyond an outer periphery of the harmonic balancer B 5 and the flange member 8 of carrying portion 7 extends over the outer peripheral ,0t edge of the inertia ring I. The result is a timing device 1 having a shell-like or shallow dish configuration. When mounted adjacent to the harmonic balancer, the device 1 is able to substantially house the harmonic balancer B, and the indicia means 9 on flange member 8 of the carrying portion assumes the task of its- 20 indicating spark ignition timing from the markings M on the harmonic balancer.

1The rigid attachment of timing device 1 to the crankshaft hub H results in the timing markings (indicia means 9) of the timing device 1 overcoming the problems of slippage of the inertia ring I with respect to the hub H. Yet the harmonic balancer remains free to continue functioning to dampen torsional vibrations in the shaft. The device may be configured to be spaced from the inertia ring when mounted adjacent the balancer so as to not inhibit this function.

Fig. 3 of the drawings illustrates an alternative embodiment of the timing device 1 of the present invention. This particular embodiment is adapted for use with a harmonic balancer in which the inertia ring I also incorporates the crankshaft pulley P. Harmonic balancers in this configuration will often include timing marks in the form of one or more notches in the edge of the pulley. In this embodiment of the invention, the carrying portion 7 does not include a flange OG C:,MhORDI.EUL SPEC\ENGNEDOC member 8. The carrying portion 7 extends radially of the disc-shaped member 3 of mounting portion 2. Indicia means 9 may be formed in, cut from or adhesively applied to the carrying portion 7 in the same manner as for the embodiment of Fig.

1 and Fig. 2. The mounting portion and means of attachment of the timing device 1 for this embodiment are the same as for the previous embodiment. The device is attachable adjacent to and in face-to-face relationship with the harmonic balancer, but in this instance the device does not extend around the balancer to substantially house it. Nevertheless, the timing device 1 of this embodiment is still adapted to assume the task of indicating spark ignition timing from the harmonic balancer.

The timing devices disclosed herein are preferably fabricated from relatively thin aluminium plate material. The plate material may be pressed and/or cut to form the device to the required configuration.

Finally, it is to be understood that various alterations, modifications and/or 15 additions may be introduced into the constructions and arrangements of parts :t previously described herein without departing from the spirit or ambit of the invention.

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Claims

1. A device for providing a reference indication of crankshaft positioning for setting and maintaining ignition timing of spark ignition engines, including: a mounting portion adapted for rigid attachment to the crankshaft for rotation therewith, the mounting portion in use extending radially of a rotational axis of the crankshaft; and a carrying portion for carrying indicia means by which the positioning of the crankshaft can be determined; wherein the device is adapted to be mounted adjacent an harmonic balancer to assume the task of indicating spark ignition timing from the harmonic balancer.

I 12. A device as claimed in claim 1 wherein, in use, the device projects tr 15 radially of the rotational axis of the crankshaft to at least an outer periphery of the harmonic balancer.

3. A device as claimed in claim 1 or claim 2 wherein the mounting portion is substantially symmetrical about the rotational axis. ~t

4. A device as claimed in any one of the preceding claims wherein the S 20 carrying portion extends from the mounting portion at a location radially distal from the rotational axis.

A device as claimed in claim 4 wherein the carrying portion is provided at a periphery of the mounting portion and is formed integrally therewith.

6. A device as claimed in any one of the preceding claims wherein the mounting portion includes at least one hole therethrough for bolted attachment of the device to the crankshaft.

7. A device as claimed in any one of the preceding claims wherein the mounting portion comprises a substantially disc-shaped member.

8. A device as claimed in claim 7 wherein the disc-shaped member of the mounting portion includes an opening formed in a central region thereof for location about a projecting edge on a hub of the crankshaft. "4 .21 9

9. A device as claimed in any one of claims 1 to 8 wherein the mounting portion extends, in use, beyond an outer periphery of the harmonic balancer and the carrying portion comprises a flange member which extends substantially transverse a plane of the mounting portion thereby creating a shell- like configuration such that the device may, in use, substantially surround or house the harmonic balancer.

A device as claimed in any one of claims 1 to 8 wherein the carrying portion extends substantially radially of the rotational axis of the crankshaft as an extension of the mounting portion.

11. A device as claimed in any one of claims 1 to 10 wherein the indicia means comprises markings formed in the carrying portion. C C

12. A device as claimed in any one of claims 1 to 10 wherein the indicia r tw t means comprises regions where material has been removed from the carrying ft t., portion. sec 15

13. A device as claimed in any one of claims 1 to 10 wherein the indicia means comprises markings which may be adhesively applied to the carrying portion. C

14. A device as claimed in any one of the preceding claims wherein the device is formed from relatively thin aluminium plate material.

15. A device for providing a reference indication of crankshaft positioning for setting and maintaining ignition timing of spark ignition engines, including: CC C a mounting portion adapted for rigid attachment to the crankshaft for rotation therewith, the mounting portion in use extending radially of a rotational axis of the crankshaft and being symmetrical about said axis; and a carrying portion for carrying indicia means by which the positioning of the crankshaft can be determined, said carrying portion extending from a periphery of the mounting portion; wherein the device is adapted to be mounted adjacent to an harmonic balancer in order to assume the task of indicating a spark ignition timing from the harmonic balancer. rF~

16. A device as claimed in claim 15 wherein the mounting portion comprises a disc-shaped member formed from relatively rigid plate material having a plurality of holes therethrough for bolted attachment of the device to the crankshaft.

17. A device as claimed in claim 16 wherein the disc-shaped member of the mounting portion includes an opening formed in a central region thereof for location about a projecting edge on a hub of the crankshaft.

18. A device as claimed in claim 16 or claim 17 wherein the carrying portion comprises a flange member formed integrally with the mounting portion and extending around the entire periphery thereof, said flange member extending substantially transverse the plane of the disc member thereby giving the device a shell-like or shallow dish configuration such that the device may, in use, substantially surround or house the harmonic balancer. Ie

19. A device as claimed in any one of claims 15 to 17 wherein the S 15 carrying portion extends substantially radially of the rotational axis of the crankshaft as an extension of the mounting portion.

A device for providing a reference indication of crankshaft positioning for setting and maintaining ignition timing of spark ignition engines substantially as herein described with reference to any one of the embodiments S 20 illustrated in the accompanying drawings.

21. An harmonic balancer assembly for mounting on an engine crankshaft including: I a hub for rigid attachment to the crankshaft for rotation therewith; I "an harmonic balancer inertia ring mounted in a resilient material such as rubber for vibration relative to the hub; and a device as claimed in any one of the preceding claims for rigid attachment to the hub. DATED: 29 June, 1998 PHILLIPS ORMONDE FITZPATRICK Attorneys for: N_1PIERRE DEGUARA C',WNWORD LIEP40510CDOC ABSTRACT The present invention relates to a for providing a reference indication of crankshaft positioning for setting and maintaining ignition timing of spark ignition in, for example, automotive piston engines. The device includes a mounting portion and a carrying portion The mounting portion is adapted for rigid attachment to the crankshaft for rotation therewith, and, in use, extends radially of a rotational axis of the engine crankshaft. The carrying portion is for carrying' indicia means by which the positioning of the crankshaft can be determined. Importantly, the device of the invention is adapted to assume the task of indicating spark ignition timing from an harmonic balancer I f it ii to I: 14 C *r Ci *r I *4 8 r DG C:\WINWORD\DELILAHSPECHENGINE.DOC