US 2471746 A
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Description (OCR text may contain errors)
May 31, 1949. R. HILBERT GAUGE TOOL FOR TIMING DIESEL ENGINES Filed Deo.
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Patented May 31, 1949 UNITED STATES `PAHNT OFFICE 2,471,746 GAUGEfrooL Fon `'rIMINo DIESEL ENGINES 4Rudolph Hilbert, salt Lake city, `Utah ApplicationDecember 23, 1948,l Serial No. .67,056 14'Claims. (C1. 33--181) This invention relates to tools for use in accurately timing Diesel engines.
Satisfactory performance of a Diesel engine requires properly timed fuel injection, neither too early nor too late with respect to the stages of` maximum compression within the respective pis` ton-cylinder combustion chambers ofthe engine. This means that the fuel injection mechanism must be precisely set relative to piston position.
The tool of the invention has particular api-H bustion chamber at the place inthe cylinder head the fuel injector, and the normally occupied by other for anchorage to a corner housing V.stud of the cylinder headso as to extend into ipredetermined engaging relationship with the injector push rod of the particular cylinder to be timed.
Each xture is equipped with an indicating gauge, q-
which, in the case of the fixture associatedfwith the combustion chamber, has itsindicator `moved by the piston as it travels through its `compression stroke, and, in the case of the fixture associated with the injector dicator moved by the corresponding travelof such injector push rod. Alprescribed procedure is fol lowed in the actual checking of the timing by these fixtures in their stated operative positions, such procedure being fully set forth in the publication Operators Instruction Manual, Bulletin No. 6304, put out by the Cummins Engine Company, Inc.
I have found that these fixtures or tools do `not `give the accurate results'intended, and that I engine timing set by their use is not precise, as
it must be for best engine performance.
Accordingly, a primary object of the invention is to provide a fixture or tool construction which will insure precise results in the timing of thew specified, or a similar, type of Diesel engine. l I attribute the major diculty in `the `stated prior tools to thefact that the corner housing` stud to which the onetool is anchored infcantilever :fashion is insufficiently strong to remain per-` used as prime moversl.
pushlrod, has its in- `i fectly rigid under the great pressure exerted by the injector push rod during the timing procedure. Even slight flexure of this stud will mean significant inaccuracy in the final result.
A feature of'my construction pursuant to the present invention, whereby this inaccuracy is eliminated, is the making of the structural frame or body which carries the gauge mechanism associated with the injector push rod, such that it straddles one ofthe recesses in the cylinder head normally occupied by a fuel. injector, and anchors securely to the pair of studs flanking such opening.
In that portion of the said frame or body which bridges the opening, I mount the second gauge mechanism operative by a piston of the engine. Thus I not only achieve accuracy which is as nearly perfect as possible, due to the rigidity of the mounting, but I also incorporate the two necessary gauge mechanisms in a single tool, which accomplishes a marked saving in theitime ordinarily expended for the timing operation, Yplus other advantages, such as lessening of manufacturing cost, and reducing likelihood of `damage to or loss of the individual gauge mechanisms.
`Further objects and features of the invention will be apparent from the following detaileddescription of the presently preferred specific embodiment illustrated in the accompanying drawing.
In the drawing:
Fig. 1 represents a front elevation of the tool;
Fig. 2, a top plan, the gauges having `been removed; and,
Fig. `3, a front elevation, drawn to a reduced scale, of the tool in operative position with respect to an appropriate type of Diesel engine, the latter being illustrated fragmentarily in vertical section taken centrally through the `pistom cylinder combustion chamber.
Referring now to the drawing: in the illustrated preferred construction, the tool of the invention embodies a rigid, structural bodymember lll arranged as a bracket support for a gauge mechanism Il adapted to be positioned-over and to engage the top of the injector push rod I2,
Fig. 3, of an appropriate type of Diesel engine I3.
The structural body I0 comprises, in this instance, an elongate base portion Illa, `which is 4horizontally disposed in the operative position of `the tool, and an elongate bracket arm portion lilb,
which is substantially vertically `disposed inthe `operative position of the tool. For best results in practice, the entire body lll `is of heavy and absolutely rigid construction, being 4preferably formed of cast iron or steel suitably machined to provide a smooth working face at lilo which fits flush against the cylinder head of the engine, as shown in Fig. 3.
While I prefer to utilize the heavy cast iron or steel construction shown, for the body lil, and machined, tool steel parts for the gauge mechanisms, as will hereinafter appear, in order to insure absolute rigidity and absolute precision in operation over long periods of use, the tool may be made of lighter and cheaper construction at the sacrice of continued preciseness over periods of long continued usage under ordinary conditions of care in handling.
In the illustrated instance, the several parts of the gauge mechanisms, which are essentially of conventional construction, are carefuliy and precisely machined prior to being assembled and iixedly mounted in the structural body iii.
The gauge mechanism il ls mounted at the upper part of the bracketl portion .ith of the body lt in and between outwardly extending, space-d lug members lil-d and ille, which are provided with aligned receiving bores for the purpose. Fixed in the receiving bore of the upper lug member ltd, as by means of screw threads, is a socket piece i4 adapted to removably receive therein an indicating gauge li of the type utilized in conventional timing practice. A set screw i6 holds the same tightly in place. Slidably mounted in the `bore of the lower lug member ite is a push rod il, which has its upper end slidably received by a bottom bore of the socket piece lll so as to extend upwardly into the socket of said piece id and engage the neovable push member (not shown) of the gauge l5. A collar i8 is secured to the push rod il, as by means of a pin i9, and a compression spring 29 encircles said push rod for compression between collar i8 and the upper lug member idd of the body as the push rod is forced upwardly during operation of the tool, such spring 2li exerting a very heavy resistance to compression as is customary.
`The lower end of push rod il is preferably though not necessarily reduced in diameter and rounded, as shown at lla, for intimate engagement with the correspondingly socketed upper end of the injector push rod i2 of the engine I3.
The structural body of the tool is so constructed and arranged as to anchor to 'the engine by means of its base portion engaging a pair of studs, indicated 2l, respectively, Fig. 3, flanking, in alignment considered longitudinally of the base portion lila, a recess 2t which normally receives a fuel injector' for a corresponding cylinder of the engine. In this way, such structural body member of the tool not only acquires a rigid and secure anchorage to the cylinder head of the engine, but its base portion is also placed in bridging position relative to the fuel injector recess 22 of the engine.
In the construction illustrated, the base portion Illa of the structural body lil of the tool .is provided With mutually spaced bores or passages, indicated 23, respectively, for receiving the studs y2 I. The tool is clamped firmly in place by means of the nuts 24.
It should `be noted that the described anchorage of the tool to the engine is a very rigid one, suiiciently rigid, I have found, to overcome any tendency for llexing due to the heavy upward push of injector push rod l2 against the bracket arm portion Mib of the structural body it.
For mounting the second gauge mechanism 25 in proper position relative to the fuel-injectorreceiving recess 22 of the engine, that part of the base portion lila of the structural body l0 which lies between the stud-receiving bores 23 and bridges the recess 22 is, in the illustrated instance, bored and reameol to receive, in a tightpressed nt, the upper shank portion 25a of such gauge assembly 25. The said upper portion 25a and a lower shank portion 25h, of larger diameter, as shown, make up an elongate gauge member which extends transversely through the base member between the stud-receiving bores 23 thereof. A tapered dowel pin Et-l is desirably fitted in a receiving bore passing through the body l and shank 25a.
The upper end of the upper shank portion 25a is formed as a socket to removably receive a gauge 2t oi' the same type as the gauge it, a set screw 2l serving to retain the same in position. A push rod 28, resilien'tly mounted within an elongate slideway 29 formed longitudinally through the two shank portions, has its lower end projecting downwardly, as at 26a, beyond the tapered lower guide tips i5-i so as to depend into the piston-cylinder combustion chamber 3d of the engine through the lower opening 22a of the fuel-injector-receiving recess 22 when the tool is in operative position relative to the engine, see Fig. 3, and has its upper end 2&5 arranged to engage and move upwardly the movable push rod 2li-l of the gauge 2t.
Checking of the engine timing is accomplished in the same manner as with the separate xtures described hereinbefore as being old in the art, the piston lil engaging the lower end 28a of the push rod 23 during such checking operation and forcing such push rod upwardly throughout its compression stroke within the engine cylinder 32 to accurately indicate on the gauge 26 the exact point of maximum compression, the injector push rod l2 meanwhile moving upwardly to produce a correlated reading on the gauge l5. The exact checking procedure is not detailed here, for it, in itself, is not new with this invention.
It can be readily seen that, because of the advantageous manner of assemblying the two gauge mechanisms into a single timing tool pursuant to the invention, notr only is precise engine timing always assured, but both mechanisms are accurately placed in operative position by a single installing operation, the two mechanisms are inseparably .maintained at all times so as to be always available for use together, and there is considerably less likelihood of damage to the individual mechanisms because of careless handling.
I have found the illustrated and specically described form of my invention to be preferable in practice to other forms which may be less costly to produce, since preciseness of result over long periods of hard use is of more importance to the purchaser than initial cost. Nevertheless, it is possible to considerably reduce the production cost by substituting other materials and well known fabrication methods for those materials and the machining specied in connection with this preferred embodiment, and still obtain a tool which will serve satisfactorily for a short period of time.
Whereas this invention is here illustrated and described in detail with respect to a particular preferred embodiment thereof, it should be understood that various changes may be made therein and various other forms of the invention may be constructed on the basis of the teachings herein without departing from the scope of the following claims.
1. An engine timing tool, comprising a rigid body member having a base portion adapted to `rest substantially horizontally upon the cylinder head of the engine, bridging a recess in said cylinder head normally occupied by a fuel injector, and having, further, a portion extending angularly from said base portion so as to extend above the corresponding injection push rod of the engine when the tool is in operative position; mutually spaced means associated with said base portion for anchoring-engagement with studs of said engine which flank the said recess; a gauge mechanism carried by said angularly extending portion of the body member, in operative position for actuation by the said injection push rod of the engine; and a second gauge mechanism carried by said base portion of the body member in operative position for actuation by the particular piston of the engine associated with said fuel injector recess.
2. An engine timing tool, comprising a rigid body member having a base portion adapted to rest substantially horizontally upon the cylinder head of the engine, bridging a recess in said cylinder head normally occupied by a fuel injector, and having, further, a portion extending angularly from said base portion so as to extend above the corresponding injection push rod of the engine when the tool is in operative position; mutually spaced passages base portion for receiving respective studs of said engine which ank the said recess at opposite sides thereof; a gauge mechanism carried by said angularly extending portion of the body member, in operative position for actuation by the said injection push rod of the engine; and a second gauge mechanism carried by said base portion of the body member in operative position for actuation by the particular piston of the engine associated with said fuel injector recess.
3.` An engine timing tool, comprising a rigid body member having a base portion adapted to rest substantially horizontally upon the cylinder head of the engine, bridging a recess in said cylinder head normally occupied by a fuel injector, and having, further, a bracket arm portion extending angularly from one end of said base portion so as to be disposed substantially vertically formed through said relative to said base portion and to extend above the injection push rod when the tool is in operative position; a gauge mechanism carried by said bracket arm portion of the body member, in operative position for actuation by the said injection push rod of the engine; a second gauge mechanism carried by the bridging part of said base portion of the body member to extend into the said fuel injector recess in operative position for actuation by the particular piston of the engine associated with said recess; and a pair of stud-receiving passages formed through said base portion of the body member at opposite sides of said bridging part thereof for mating with a pair of cylinder head studs of the engine which flank the said fuel injector recess in alignment longitudinally relative to said base portion of the body member.
4. An engine timing tool, comprising a rigidly formed, elongate base member adapted to rest substantially horizontally upon the cylinder head of the engine, comprehending a recess therein normally occupied by a fuel injector; a rigidly formed, elongate bracket arm rigidly joined to said base member so as to extend upwardly above the corresponding injection push rod of the engine when the tool is in operative position; rigid gauge-mounting means formed at the upper part of said bracket arm; a movable gauge member slidably mounted in said gauge-mounting means, and extending downwardly in the operative position of the tool for engagement by the said injection push rod of the engine; a pair of studreceiving passages formed through said base member, said passages being mutually spaced along the length of said base member for receiving a pair of cylinder head studs which flank the said fuel injector means at opposite sides thereof; an elongate gauge slideway member extending transversely through said base member between said stud-receiving passages and in fixed relationship with said base member, so as to be substantially vertically disposed in the operative position of said tool and depend into the said fuel injector recess; and gauge slide means movably mounted in said slideway, said slide means including a push rod member which projects from the lower rod of said slideway member for engagement by thecorresponding piston of said engine.
No references cited.