US3508528A

US3508528A - Internal combustion engine valve operating means

Info

Publication number: US3508528A
Application number: US739368A
Authority: US
Inventors: Mark Sherbinsky
Original assignee: International Harverster Corp
Current assignee: Navistar International Corp
Priority date: 1968-06-24
Filing date: 1968-06-24
Publication date: 1970-04-28
Anticipated expiration: 1987-04-28
Also published as: DE1923782A1

Description

April 1970 M. SHERBINSKY m INTERNAL COMBUSTION ENGINE VALVE OPERATING MEANS 2 Sheets-Sheet i Filed June 24, 1968 INVEN TOR MA PK SHE? B/NSKY, 1Z1

ATT

April 28, 1970 M. SHERBINSKY 11: 3,508,528

INTERNAL COMBUSTION ENGINE VALVE OPERATING MEANS Filed June 24, 1968 2 Sheets-Shet 2 F/G'b. W

lNVENTOR MARK SHERB/NSKY,IU

United States Patent 3,508,528 INTERNAL COMBUSTION ENGINE VALVE OPERATING MEANS Mark Sherbinsky III, Fort Wayne, Ind., assignor to International Harvester Company, Chicago, Ill., a corporation of Delaware Filed June 24, 1968, Ser. No. 739,368 Int. Cl. F01l1/06, 1/18 U.S. Cl. 12390 12 Claims ABSTRACT OF THE DISCLOSURE A valve operating assembly in an internal combustion engine including rocker arm means and valve spring means both of which engage the valve stems intermediate the end of the length thereof for actuation of the valve. Actuation of the valves by operative connection to the valve stem intermediate the extremities thereof and between spaced value guides therefor conserves space and reduces the overall size of the engine. The pivotal axis of the rocker arm means is vertically spaced below a plane which is perpendicularly to the longitudinal axis of the valve stem and which extends through the uppermost end of the lower of the spaced valve guides; and the rocker arm means extends from its pivotal axis below the cam shaft to its point of engagement with the valve stem.

This invention relates to internal combustion engines and more particularly to improved valve operating assemblies.

In conventional engines rocker arm assemblies often are arranged to actuate an associated valve by acting on the upper end of the valve stem to open the valve. Such an arrangement obviously requires space which otherwise would not be required if the rocker arms could be positioned in some other manner. Furthermore, conventional engines generally use coil compression springs positioned near the upper end of the valve stem, and these also require additional space. The invention herein minimizes the space requirements for the rocker arms and valve springs of the valve operating assembly.

A principal object of this invention is to provide in an internal combustion engine a compact valve operating assembly which will reduce the overall size of the engine.

Another object is to provide a valve arrangement in an internal combustion engine wherein the stemmed valve member is reciprocably supported in spaced Valve guides, and the rocker arm means used to actuate the stemmed valve member engages the latter intermediate its extremities.

Another object is to provide a valve operating assembly wherein both the cam actuated rocker arms which open the valves and the spring means which closes the I valves engage the stemmed valves intermediate the ends of the valve stem to thereby reduce the space required by the valve operating assembly. Also the stress on the valve stem is reduced considerably in comparison to the usual cantilever design where the rocker arm engages the end of the valve stem. The assembly also affords greater tolerance to side loads. 1

Another object is to provide a valve operating assembly wherein the valve spring means and the rocker arm means are positioned substantially in the space between two rows of reciprocating valve members to thereby further conserve space and reduce the overall size of the engine. The above and other objects and advantages of the invention will be more readily apparent when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a broken away plan view of a portion ice of an engine cylinder head showing valves, valve rocker arms and associated valve springs;

FIGURE 2 is a partial elevation view in section taken along line 22 of FIGURE 1;

FIGURE 3 is an elevation view in section taken along line 3-3 of FIGURE 1;

FIGURE 4 is an enlarged view of a portion of one of the valve stems and a collar attached thereto which acts as a bearing for an associated valve spring; and

FIGURE 5 shows the two halves of a member used to secure a flange member on the valve stem.

Referring now to the drawings wherein like reference characters refer to similar parts there is shown an engine part 10 which is a portion of an engine cylinder head in which are disposed a plurality of inlet and exhaust valves. Two of these are shown as inlet valve 12 and exhaust valve 14 disposed for reciprocating movement in response to actuation by a cam shaft, associated rocker arms and valve spring means. A valve cover 16 having a generally inverted U-shape cross-section encloses the upper portion of the cylinder head and is secured to the head by suitable means such as bolts 17. A plurality of bearing surfaces 18 may be provided in the cover 16 for supporting a cam shaft 19. Cam lobes of which two are shown in FIGURE 1 as 20 and 22 operate rocker arms such as 24 and 26 which in turn

actuate valves

14 and 12 respectively. Spring members are included in the assembly to urge the valves to a closed position. Two such spring members are shown herein and are designated by

reference characters

28 and 30.

One of the important objectives to be accomplished by this invention is to arrange the working parts of the valve assembly in a compact arrangement to thereby conserve space and reduce the engine size. To that end the cylinder head is constructed to provide split valve guide means enabling the rocker arms and valve springs of the valve actuating mechanism to be operatively connected to the valve stem intermediate its length. In addition, the arrangement is such that the rocker arms and closing springs are positioned substantially between the valves and extend in a substantially transverse direction with respect to the cam shaft. It will also be observed that the rocker arms and valve springs lie substantially in a region bounded by the cam shaft and valve members.

The cylinder head is constructed to provide spaced valve guide means for each of the valve members. The space valve guides include upper and

lower valve guides

32 and 34 for valve stem 15 of valve 14 and upper and

lower valve guides

36 and 38 for valve stem 13 of valve 12. The

upper valve guides

32 and 36 comprise substantially inverted L-shaped upstanding members preferably formed as an integral part of the cylinder head casting. It will be appreciated that there will be a plurality of

upper valve guides

32 and 36 depending on how

many valves

14 and 12 are present in particular cylinder head. Each of the

upper valve guides

32 and 36 comprise inwardly extending

arms

33 and 37 respectively which have formed therein, corresponding liner members such as 33a shown in FIGURE 2. The

lower valve guides

34 and 38 are also formed in the cylinder head and are spaced from the corresponding upper valve guides.

It will be observed that the axis of cam shaft 19 lies substantially below the upper ends of the

valve stems

13 and 15, the cam shaft being supported by the bearing surfaces 18 of the cover 16. It will also be noted that the valve cover 16 is so constructed that the inner surface 40 thereof just clears the upper ends of the

valve stems

13 and 15.

Collars or

flanges

42 and 44 are connected to the

valve stems

15 and 13 respectively, intermediate the ends of the valve stems and between the spaced valve guides. The

collars

42 and 44 act as bearing surfaces to receive 3 the force of the ends of the

rocker arms

26 and 24 thus forming part of the operative connection bet-ween the rocker arms and the valve stems.

Collars 46 and 48 may be secured to the valve stems 15 and 13 respectively at a position just slightly below

collars

42 and 44 and are engaged by the

spring members

28 and 30. The method of securing

collars

46 and 48 to the valve stems is illustrated in FIGURE 4. A tapered member 47 split vertically as shown in FIGURE may be used to secure collars such as 46 and 48 on the valve stems.

The

rocker arms

24 and 26 are disposed transversely with respect to the axis of cam shaft 19 and lie under the cam shaft. The one end of

rocker arms

24 and 26 may be mounted for pivotal movement on ball pivots 5'0 and 52 respectively, the latter being positioned by suitable means in the cylinder head. In the embodiment shown these ball pivots lie substantially in line with the valve members. From their pivots the rocker arms extend below and transversely with respect to the cam shaft. The opposite ends of

rocker arms

24 and 26 are formed with bifurcated

portions

54 and 56 respectively to engage the upper surfaces of

flanges

44 and 42 attached respectively to

valve stems

13 and 15. The

flanges

44 and 42 receive the force of the ends of the rocker arms as they are pivoted downwardly by the lobes of the cam shaft acting on the rocker arms intermediate the ends thereof. It will be observed that the positioning of the rocker arms to act on the valve stems intermediate their length reduces the space requirements which otherwise -would be necessary if the rockers were positioned to engage the valve stems at their upper ends.

The pair of

valve spring members

28 and 30 are of the same configuration as most clearly seen in FIGURE 1 but are reversed in the assembly with respect to each other.

Thus only spring member 28 will be described in detail, corresponding parts of spring member 30 being designated with the same reference character plus the sufiix a. The spring members are actually arranged in nested pairs in the valve operating assembly. It will be apparent that there are as many spring members as there are valves. As will be evident from further description, each spring operates on two valves and each valve is actuated by arm members of two springs. These valve springs are also described in my copending application identified as Ser. No. 739,369, filed June 24, 1968.

The spring member 28 is a resilient wire member formed into three spaced and substantially axially aligned coils or coiled

loop portions

58, 60 and 62. Two substantially U-shaped transversely extending

arm members

64 and 66 interconnect the coils with the coil 60 being the internal coil or middle loop portion and coils 58 and 62 being the external coils. The internal coil 60 is connected to both

arm members

64 and 66. The

arm members

64 and 66 are formed with

cross bar portions

68 and 70 respectively.

The external coils 58 and 62 are formed with free ends or anchoring ends 72 and 74 respectively which are used to anchor the spring member 28 in the cylinder head. FIGURE 3, for example, shows the free end 72 of spring member 28 anchored in opening 76 in the cylinder head and free end 74a of spring member 30' anchored in opening 78. These anchoring ends function as reaction points when torque is applied to the spring arm members. The

spring members

28 and 30 are pretensioned by proper positioning in anchoring recesses in order to give the desired lifting force on the valve.

A plurality of

recesses

80 and 82 are formed along the length of the cylinder head on opposite sides of the cam shaft axis to accommodate the coils of the valve spring members.

The cross bar portion 70 of spring member 28 and the cross bar portion 68a of spring member 30 engage the underside of collar 46 which is attached to valve stem of valve 14 to urge the latter to a closed position. The cross bar portion 70a of spring member 30 and the cross bar portion 68 of spring member 28 engage the underside of collar 48 which is attached to valve stem 13 of valve 12 to urge the latter to a closed position.

It will be observed that cross bar portion 68 acts on the inwardly extending portion of collar 48 on valve stem 13 and cross bar portion 70a acts on the opposite and outwardly extending portion of collar 48. Likewise cross bar portion 68a acts on the inwardly extending portion of collar 46 on valve stem 15, and cross bar portion 70 acts on the opposite and outwardly extending portions of collar 46.

Both the rocker arms and the arms of the spring members act on the valve stems along an intermediate or central portion of the valve stems, the rocker arms exerting a downward and opening force through the

collars

42 and 44 and the spring members exerting an upward and closing force through collars or

flanges

46 and 48. This operative connection to the valve stems by both the rocker arms and the spring members substantially minimizes the height of the engine. Furthermore, the positioning of both the rocker arms and the spring members under the cam shaft and between the valve members further reduces the space necessary to accommodate the valves and valve operating assembly.

In operation valve 12 is opened by action of the lobe 20 of the cam shaft on rocker arm 24. The rocker arm 24 pivots downwardly on ball pivot 50 and acts on collar 44 secured to the valve stem 13. This action, of course, moves the U-shaped arm member 64 of spring member 28 downwardly and builds up the bending stress in the

coils

60 and 62 of spring member 28. Because of the direction of winding of the coil 60, the arm member 60 associated with valve 14 exerts an upward or lifting force on valve 14 to thereby more strongly urge the latter to a closed position.

In addition, the downward or opening movement of valve 12 moves arm member 66a of spring member 30 downwardly increasing the bending stress in the coils 58a and 60a. As a consequence, the arm member 640 exerts additional lifting force on valve 14 through arm member 66.

As the cam shaft rotates to open valve 14, substantially the same sequence of events take place. In such case, the downward or opening movement of the valve 14 puts additional bending stress on the coils 62a and 60a of spring member 30 and on

coils

58 and 60 of spring member 28. The arm member 66a associated with valve 12 then more strongly urges the latter to a closed position. The opening movement of valve 14 moves arm member 66 of spring member 28 to increase the bending stress of coil 60, and as a consequence the arm member 64 urges the valve 12 to a closed position with greater force.

What is claimed is:

1. In an internal combustion engine having a valve operating earn shaft associated therewith the combination comprising:

a valve member having a valve head and a valve stem rigidly connected thereto;

a pair of vertically spaced valve guides for slidingly supporting said valve stem therein;

a rocker arm for actuating said valve member, said rocker arm having two ends and being adapted to be actuated by the cam shaft to urge said valve member to an open position;

pivotal mounting means supporting one end of said rocker arm for rocking movement about an axis vertically spaced below a plane perpendicular to the longitudinal axis of said valve stem and extending through the uppermost end of the lowermost valve guide of said pair of valve guides;

means forming an operative connection between the other end of said rocker arm and said valve stem along an intermediate portion of said valve stem and between said spaced valve guides,

said rock-er arm extending from its pivotal mounting below and transversely of the axis of the cam shaft to said operative connection with said valve stem. 2. The combination of claim 1 including a valve spring for urging said valve member to a closed position, and means forming an operative connection between said valve spring and said valve stem along an intermediate portion of said valve stem and between said spaced valved guides. 3. The combination of claim 1 including a valve spring for urging said valve member to a closed position, said valve spring including an arm member, and means forming an operative connection between said valve spring arm member and said valve stem along an intermediate portion of said valve stem and between said spaced valve guides. 4. The combination of claim 1 including a torsion valve spring for urging said valve member to a closed position, said valve spring comprising at least two axially spaced coil portions and an arm member interconnecting said coil portions, means forming an operative connection between said valve spring arm member and said valve stem along an intermediate portion of said valve stem and between said spaced valve guides. 5. The combination of claim 4 wherein said arm member of said torsion valve spring is a substantially U-shaped member, and said rocker arm is nested between the two legs of said U-shaped member, the pivotal axis of said rocker arm being vertically spaced below the longitudinal axis of said coil portions. 6. In an internal combustion engine having a valve operating cam shaft associated therewith the combination comprising:

member including a plurality of axially spaced coil portions and arm means interconnecting said coil portions, and further including pivotal mounting means for said rocker arm means disposed between said coil portions, said rocker arm means and said valve spring arm both extending substantially transversely of the axis of the cam shaft. 10. In an internal combustion engine having a valve 10 operating cam shaft associated therewith the combination a valve member having a valve head and a valve stem rigidly connected thereto;

pivotal rocker arm means for actuating said valve member to an open position, said rocker arm means be ing pivotal about an axis substantially parallel to the longitudial axis of said cam shaft to effect actuation of said valve member, the pivotal axis of said rocker arm means being vertically spaced below a plane perpendicular to said valve stem and extending through the uppermost end of the lowermost valve guide of said pair of valve guides;

valve spring means for urging said valve member to a closed position;

means forming an operative connection between said rocker arm and said valve stem along an intermediate portion of said valve stem and between said spaced valve guides; and

means forming an operative connection between said valve spring means and said valve stem along an intermediate portion of said valve stem and between said spaced valve guides.

7. The combination of claim 6 including collar means on said valve stem for receiving the opening thrust of said rocker arm and the closing thrust of said spring means.

8. The combination of claim 6 wherein said valve spring means is a torsion spring comprising an arm member extending transversely of the cam shaft axis and which engages the valve stem of the valve member, and

said rocker arm extends transversely of the cam shaft axis and engages the valve stem of the valve member.

9. The combination of claim 6 wherein said valve spring means comprises a torsion spring comprising:

valve means comprising at least two separate valve members each having a valve head and a valve stem;

vertically spaced valve guides comprising upper and lower valve guides for slidably supporting each of said valve stems therein;

rocker arm means for actuating each of said valve members to an open position in response to actuation by the cam shaft, said rocker arms extending transversely to the cam shaft axis;

valve spring means for urging said valve members to a closed position;

means forming an operative connection between each i, of said valve stems and its associated rocker arm means along an intermediate portion of said valve stem and between said upper and lower guides;

pivotal mounting means for each of said rocker arms means, each of said rocker arm means being pivotal about an axis substantially parallel to the longitudinal axis of said cam shaft to effect actuation of the valve member associated therewith, the pivotal axes of said rocker arm means being vertically spaced below a plane perpendicular to said valve stems and extending through the uppermost end of the lowermost valve guide of each of said pairs of valve guides.

11. The combination of claim 10 wherein said valve spring means are torsion spring members,

and further including means forming an operative connection between said spring members and their associated valve stems along an intermediate portion of said valve stem and betweenv said upper and lower valve guides.

12. The combination of claim 11 wherein said torsion spring members each comprise at least two axially spaced coil portions disposed in planes substantially perpendicular to the cam shaft axis and an arm member interconnecting said coil portions for operatively engaging said valve member,

said rocker arms extending substantially transversely of the cam shaft axis and between the planes defined by said coil portions.

References Cited UNITED STATES PATENTS 1,477,736 12/ 1923 Wennerby. 1,974,802 9/ 1934 Chilton. 2,824,554 2/ 1958 Sampietro. 2,857,896 10/1958 Schnepel.

3,060,916 10/1962 Buchi. 3,352,293 11/1967 Hulten. 3,358,659 12/1967 Renger. 3,430,614 3/ 1969 Meacham. 658,594 9/1900 Schartle et al.

1,756,796 4/1930 Noble 12390 FOREIGN PATENTS 522,998 7/1940 Great Britain.

0 AL LAWRENCE SMITH, Primary Examiner US. Cl. X.R.