Патент USA US2404032код для вставки
July 16, ‘1946. G. E. BURKS - 2,404,032 VALVE TAPPET- MOUNTING Filed July 9, 1945 5 Sheets-Sheet 1 G- . ,HIWmHI: IN VEN TOR. George E. Burks BY - aw?y. 72W ATTORNEY. July 16, 1946. ‘ s. E. BURKS 2,404,032 ‘VALVE TAPPET -MOUNTING Filed July 9, 1945 3 Sheets-Sheet 2 I m m Tm George E. Bur-ks ATTTORAE)’. ‘ July 16, 1946. 2,404,032 ' a. E. BURKS VALVE TAPPET mopn'rme Filed July 9, 1945 ' 3 Shéets-Sheet 3 QN “ \“N\ \ ‘\ \ mmMN \\ \gé emMN‘ 3. ‘ NF.mm |HP| i \\\\ l MN NJIY vQMmm m4. S \N 1V. .N Q. ‘INVENTOR. 1| ' George E. Burks a/MZI-W' ‘ ATTORNEY. 02,404,032 Patented July 16, 1946 UNITED STATES PATENT OFFICE 2,404,032 VALVE TAPPET MOUNTING George E. Burks, Peoria, 111., assignor to Cater pillar Tractor 00., San Leandro, Calif., a cor poration of California , Application July 9, 1945, Serial No. 603,799 '1 Claims. (Cl. 123--90) 1 2 jects and advantages of the invention are made The present invention relates to the mounting of valve tappets or guides for valve tappets which apparent in the following speci?cation wherein reference is made to the accompanying drawings are employed as a part of the valve operating , which illustrate a preferred form of the inven mechanism of an internal combustion engine. tion applied to an ‘internal combustion engine 6 Conventional types of internal combustion en of conventional design. gines comprise cylinders usually disposed vertical In the drawings: ly in a cylinder block. Valves which control the Fig. 1 is a. diagrammatic view in side elevation intake of air and the exhaust of residual prod of an internal combustion engine with portions ucts of combustion from the cylinders are actu broken away and illustrated in section to show ated by mechanism which include push rods and the application thereto of valve tappet mount; tappets arranged vertically adjacent the cylinder ings embodying the present‘ invention; block. The lower ends of the tappets are en gaged by cams on the cam shaft disposed longi~ Fig. 2 is a. front elevation of the engine shown in Fig. 1 with a portion illustrated in section to tudinally of the block and driven in timed rela disclose details of construction of the invention: ‘ Fig. 3 is an enlarged fragmentary sectional tion to the reciprocal action of the pistons in 15 the cylinders. It is desirable that the cams en gage squarely against the lower ends of the tap- \ pets as the timing and distance of opening of ' the valves are critical factors in perfect engine performance. If the tappet guides are misaligned, 20 the tappets do not seat squarely against the cams Fig. 4 is a sectional‘ view taken on the line IV——IV of Fig. 3; and ‘ but may ride on one edge of the cam face. As a result of such operation, excessive wear takes mechanism in a typicalinternal combustion en gine is illustrated in Figs. 1 and 2 wherein the place between the cam and shaft which affects the timing and opening of the valves. The tap pet guide also becomes worn because of such misalignment and various other undesirable re sults occur. view taken on the line III-—III of Fig. 2; Fig. 5 is a sectional view taken on the line V-V of Fig. 3. , The general arrangement of valve operating engine is illustrated at I0. Conventional cylin ders, shown in dotted lines at Ii in Fig. 2, are disposed within the engine block and pistons l2 reciprocate in the cylinders and impart rotation to a crank shaft I! by means of connecting rods H. The upper ends of the cylinders are provided with intake and exhaust valves such as indicated at i5 and these valves have stems l6 engaged by rocker arms ll which are pivotally mounted as ~ It has been common practice to mount valve tappet guides against the side of the engine block on a ?at surface and to secure them in place by cap screws. This ‘practice required many ma chining operations, such as the production of a ?at surface on the block and on the bracket, bor at l8. ‘Springs, not shown, normally hold the valves IS in closed positions andthey are opened ing the tappet guide through the brackets and 35 in timed succession, and in proper relation to the providing for the cap screws which extended reciprocal action of the pistons in the cylinders, through the 'bracket and into the block. Each by means of pusher rods 19 disposed on the out of these operations had to be separately‘ per side-of the _-cylinder"iblock and engaging at their formed with no particular relation to the others upper ends‘ with ,ithe rocker arms l1 and at their 40 or to the line of the cam shaft bearings in 'the lower‘endsl‘with'tappets 20. The tappets 20 are block. Even allowing a minimum'tolerance prac-, mounted for. reciprocation in guides 2i and have tical for machining operationsjof this kind, slight lower . fe'nds projecting downwardly from said errors in each operation would sometimes accu mulate to produce a substantial misalignment. _ It is‘ an object of the present invention to'over-. come the disadvantages herein referred to and to provide a mounting for valve tappets which insures perfect alignment of the tappets with . desand engageable with cams 22 on a cam 45 shaft '23. The cam shaft 23 is journaled for-“r0 ' tation in spaced bearings 24 which, as illustrated in Fig. l,.are cast as integral parts of the engine block. The cam shaft is connected with the crank shaft I3 for rotation thereby by means ‘of a relation to the cam shaft of the engine upon train of gears, not shown, in accordance with 50 which they are mounted. A further object of conventional practice. By reason of this con the invention is to provide a means for mount nectlon. the cam ‘shaft is rotated in timed rela ing valve tappets which requires a. minimum of tion to the crank shaft and to the, reciprocal ' simple machining operations capable of being action of the pistons which drive the crank shaft. performed in a manner greatly to reduce the‘pos The arrangement of the individual cams'22 on sibilities of error: Further and more specific ob- 55 2,404,032 ' J the cam shaft is such that during each rotation of the shaft, each one of the intake and exhaust valves II is opened in properly timed relationship to the operation of its respective piston, The engine illustrated in Fig. l is of the six cylinder type and each cylinder has an associated pair of valves, push rods l9, tappets 29 and tap pet guides 2|. The pairs of tappet guides 2| are illustrated herein as connected in groups of three plementary seating surfaces 21 on the casting are true with relation to the vertical bores in the tappet guides 2|, the lower ends of the tap pets must rest squarely on the surfaces of the cams 22. The semi-cylindrical surfaces 21 on the casting which includes the tappet guides 2| are somewhat larger than the rest of the casting and are spaced between the longer portions which pairs each so that two such groups are employed 10 form the guides 2|. Hence, the entire casting may be supported between centers on a lathe to accommodate six cylinders. It is, of course, to - be understood that the invention herein de ' scribed is applicable to engines having any num or similar machine for formation of true sur faces on the members 21 and the same centers established at the ends of the casting for form ber of cylinders and that the grouping of the tappet guides may be varied from the arrange 15 ing these surfaces may be used in aligning the work for boring out the guides 2| for reception ment herein illustrated. ‘ In‘ conventional construction, the tappet guides 2| have been formed as a part of a casting having a ?at surface which flat surface is bolted ?ush against a ?at-surface on the engine block for support. Such construction has been conducive to ‘misalignment of the guides through error vin laying out and machining operations so that in some cases the lower ends of the tappets have not of the reciprocal tappets 20. Consequently, the bores of the tappet guides can readily be formed normal to the longitudinal axis about which the surfaces 27 are turned and as the seats 2| in the engine block which receive the surfaces 21 are formed parallel to the cam shaft bearings, a perfect seating of the tappets against the sur faces of the cams on the cam shaft is assured. . rested squarely» on the surfaces of the cams 22 25 The alignment of the tapped holes for the cap screws 29 is easily accomplished and does not but rather have been anguiarly disposed so that they engaged one edge only of the cams with the result that excessive wear and imperfect engine affect the position of the bracket which the cap screws support. a I claim: 1. A device for mounting valve tappets or the According to the present invention, the tap 30 like on the side of an engine block which com Det guides 2| are formed as a part of a casting prises a casting having portions of cylindrical or ‘castings which are secured to the engine contour formed thereon and adapted to be re block in a manner which practically elimi operation follows. . ceived in recesses of complementary contour in nates possibility of their misalignment. For example, ‘as shown in Figs. 1 and 3, the tappet 35 the block. 2. A device for mounting valve tappets or the guides 2| areformed in groups of three pairs like on the side’ of an engine block comprising integrally cast and connected‘ by semi-cylindrical a casting having tappet guides bored therein, connecting members 25 which have centrally dis semi-cylindrical seat portions on the casting - posed reinforcing ribs 28. The exact shape of the connecting members 28 and ribs 26 is subject 40 formed about an axis at right angles to the axes of said tappet guides and adapted to seat in re to variation and is not an essential characteristic cesses of complementary contour in the block. of the mounting structure so long as it forms a 3. Adevice for mounting valve tappets on an rigid connection between the pairs of guides 2|. engine block for engagement with spaced cams Between the guides 2| of each pair a similar but on an engine cam shaft which comprises, a brack shorter connecting shape is employed and is et, tappet guides bored in the bracket, and 9. cy provided with an enlarged semi-cylindrical por lindrical surface on the bracket formed on an tion 21, see also Figs. 4 and 5, capable of being axis at right angles to the axes of said tappet ' machined to present a perfect semi-cylindrical guides, whereby the cylindrical surface will seat contour. This surface 21 is adapted to be dis in a cylindrical recess bored in the block parallel posed against a registering semi-cylindrical sur face 28 ‘machined on the side of the engine block, 50 to the cam shaft to position the tappets at right angles to the cam shaft. ‘ as best illustrated in Fig. 2, where the block is 4. A device for mounting valve tappets on an shown as cast to a shape providing surfaces for engine block for engagement with spaced cams such machining. Cap screws 29 are employed to on an engine cam shaft which comprises, a brack secure the castings against the side of the block with the semi-cylindrical machined surfaces 21 55 et, tappet guides bored in the bracket, and a ' seating against the complementary concave sur cylindrical surfac on the bracketformed on an axis at right angles to the axes of said tappet faces 28 formed in the side of the block. With this construction a relatively small number of cap screws is needed as the complementary semi guides, whereby the cylindrical surface will seat in a cylindrical recess bored in the block parallel , cylindrical surfaces provide an accurate seat 00 to-the cam shaft to position the tappets at right which holds the casting in alignment and the cap angles to the cam shaft and means to secure the bracket against the engine block. screws are necessary only to prevent the casting from moving away from the block. 5. A device for mounting valve taDDets on an The construction herein described lends itself engine block comprising, a plurality of tappet 65 to simple and easily performed machining oper guides formed integrally with connecting and ations which insure accuracy in the alignment supporting members, and a plurality of aligned of the tappet guides. For example, the semi conve'x seating portions on said connecting and supporting members adapted to register with cylindrical concave seats 28 in the side of the complementary concave seats formed on the en block may be bored at the same time that the block is set up for machining the crank shaft 70 gine block. 6. A device for mounting valve tappets onan bearing brackets and the bearings 24 for the ion engine block comprising, a plurality of tappet .. gitudinally extending cam shaft 23. This in guides formed integrally with‘ connecting and sures~thatfall offfthe‘ seats 28 will be perfectly _ supporting members, and a plurality of aligned ‘ aligned with the‘ crank's'hsit so that if the com~ 75 convex seating portions on said connecting and zgoeose - supporting members adapted to register with ' e nesting members, aligned convex seating portions complementary concave seats formed on the‘ en on said connecting members having semi~cy1in gine blockseid seating portions being positioned dricalosurfaces formed on a common center line between tappet guides. V and adapted to register with complementary 7. A device for mounting valve tappets on an 5 concave seats formed in the engine block. engine block comprising a casting including .por tions for tappet guides and intermediate con GEORGE E. BURKS.