Abstract:
A valve lifter guide for internal combustion engines for preventing rotation of the valve lifters. The guide consists of an elongated support which is affixed to an internal combustion engine block, and spaced resilient cantilever supported fingers extending from the support have a free end which engages an orientation flat surface on the valve lifter and prevents valve lifter rotation. The resiliency of the fingers simplifies installation of the guide and assures engagement of the guide fingers with the lifter flat surface. An embodiment includes alignment features to facilitate assembly of the valve push rods.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to guides for roller valve lifters for internal combustion engines to prevent rotation of the valve lifter about its axis. 
     2. Description of the Related Art 
     Valve lifters for internal combustion engines reciprocate within the engine block and through a lifter rod operate the intake and exhaust valves. The lower end of roller valve lifters includes a roller which engages a lobe upon the engine camshaft. By using a roller at the lower end of the valve lifter, friction between the lifter and camshaft is reduced providing superior engine performance. However, the lifter roller must rotate about an axis parallel to the axis of rotation of the camshaft and guide means must be used to properly maintain the orientation of the valve lifter in this respect. 
     Orientation of roller valve lifters to the camshaft is usually accomplished by forming a flat orientation surface on the valve lifter which is oriented to the axis of the valve lifter roller and cooperates with a guide engaging the lifter orientation surface to prevent rotation of the valve lifter about its axis. Usually, two parallel flat surfaces are defined upon each lifter located upon opposite sides of the lifter axis. 
     In the past, valve lifter guides for internal combustion engines to prevent valve lifter rotation have been formed of metal and include flats which correspond to the configuration of the lifter flats. The lifter reciprocates within the guide openings and the relationship between the guide openings and lifter flats prevents valve lifter rotation. The metal-to-metal contact between the valve lifters require clearances and the guides produce wear which increases the clearances between the moving parts, and excessive noise may be generated and improper cam lobe tracking can occur. Further, conventional metal valve lifter guides are relatively heavy, expensive to manufacture and assemble within the engine, and are prone to improper assembly if care is not taken. 
     Many of the aforementioned shortcomings of internal combustion engine valve lifter guides have been overcome by the applicants&#39; roller valve guide shown in U.S. Pat. No. 5,088,455. The lifter guide shown in this patent is preferably formed of synthetic self-lubricating material and is inexpensive to manufacture, long wearing and easy to install. However, the valve lifter guide shown in U.S. Pat. No. 5,088,455 is of such a construction as to accommodate only certain types of internal combustion engines, and cannot readily be used with some types of V-block or straight engines. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to provide a low cost effective anti-rotation guide for internal combustion engine valve lifters which may be readily used with V-block engines, and may readily be designed to accommodate various sizes of engines, even those in which the valve lifter bores are not centered upon a common centerline, and/or the lifters operate at differing angles relative to the engine block face. 
     Another object of the invention is to provide an anti-rotation valve lifter guide using a plurality of resilient fingers for engaging the valve lifter and preventing rotation thereof, the resiliency of the fingers insuring an effective engagement between the guide and the valve lifters. 
     Yet another object of the invention is to provide a versatile anti-rotation valve lifter guide utilizing resilient cantilever mounted fingers and wherein a valve push rod guide is mounted upon the fingers having alignment means to facilitate push rod assembly with the valve lifters. 
     SUMMARY OF THE INVENTION 
     The valve lifter guide of the invention can be formed of any material, including a polymer, stamped metal, ceramic or any material capable of being formed in the desired configuration. The guide must have a limited degree of resiliency, and from a cost and manufacturing standpoint, molding the valve lifter guide from a synthetic polymer is desirable. 
     The valve lifters in a V-block internal combustion engine are located within cylindrical guide bores obliquely related to the vertical. Half of the lifters are located on one side of the engine longitudinal axis, while the other half of the lifters are on the other side of the engine axis. A valve lifter guide in accord with the invention is associated with the valve lifters on both sides or banks of the engine and it is only necessary to install a single guide for association with all of the valve lifters used in a V-block engine arrangement. 
     The valve lifters with which the guide of the invention is used are of cylindrical configuration having a roller located at the lower end for engagement with the engine camshaft. At the upper end of the valve lifters, one or a pair of spaced parallel flat orientation surfaces are defined in diametrically opposed relationship, and one of these flat orientation surfaces is engaged by the guide along a linear line of engagement to prevent rotation of the valve lifter about its longitudinal axis. The upper end of the valve lifters are engaged by valve push rods which operate the engine&#39;s inlet and exhaust valves by a rocker arm assembly. 
     The valve lifter guide includes a central body of an elongated form having parallel lateral sides. The body includes engine attachment means, such as holes for receiving bolts or other mounting structure, whereby the guide may be firmly affixed to the engine block at a central location and the length of the guide body is parallel to the engine length. 
     A plurality of resilient cantilever supported fingers extend from each of the guide body lateral edges. These fingers are relatively stiff, but capable of limited resilient deflection relative to the body. The fingers are spaced from each other along the associated body lateral edge, and the length of adjacent fingers will normally be different in order to accommodate the location of the engaged valve lifter with which the finger is associated. 
     The outer end of each of the guide fingers is formed with a linear surface for engaging a flat valve lifter orientation surface. It is this linear engagement of the outer end of a finger with a valve lifter flat surface which prevents rotation of the valve lifter about its axis. 
     In the preferred embodiment of the invention, the finger valve lifter linear engaging surface is defined by forming the outer end of the guide fingers with a convex surface created by shaping the finger ends of a J-configuration wherein the end of the fingers extends away from the engine block. The convex surface defined by the J-configuration extends the width of the fingers defining a linear line of contact with the valve lifter flat orientation surface, and also, the length of the fingers is such that the finger ends will simultaneously engage the surface of the engine adjacent the guide bores in which the valve lifters are received. The resilient nature of the fingers permits this dual engagement of the fingers with the valve lifter and the engine block and, of course, the length of the fingers is accurately controlled during manufacture to permit this dual engagement of the finger ends. 
     As the convex J-configurations formed on the finger ends have a length parallel to the central valve guide body, and, in most cases, are of a width equal to the finger width, the resultant linear line of contact between the finger ends and the valve lifter flat guide surfaces effectively prevents rotation of the valve lifters. 
     In a variation of valve lifter guide utilizing the concepts of the invention, the ends of the fingers are formed with a flat surface which directly engages the valve lifter flat orientation surface. Additionally, aprons are defined on the end of the guide fingers extending from the fingers&#39; flat surface whereby a valve lifter rod guide may be formed on each finger end to facilitate the assembly of valve lifter rods with the valve lifter ends. The valve lifter guides include an opening for receiving the valve lifter rods, and alignment structure, such as oblique surfaces, are defined on the rod guides adjacent the openings to facilitate insertion of the valve rods therethrough. 
     A valve lifter guide constructed in accord with the invention may be economically manufactured, is low cost, and effectively prevents valve lifter rotation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein: 
     FIG. 1 is a perspective view of a valve lifter guide utilizing the concepts of the invention, 
     FIG. 2 is a top plan view of the guide of FIG. 1, 
     FIG. 3 is a side elevational view of the lifter guide as taken from the bottom of FIG. 2, 
     FIG. 4 is an end elevational view of the valve lifter guide, 
     FIG. 5 is an elevational sectional view of internal combustion engine structure illustrating a portion of an engine block having valve lifters located therein, and the guide of FIGS. 1-4 engaging the valve lifter orientation surfaces, 
     FIG. 6 is a perspective view of an embodiment of valve lifter guide utilizing the inventive concepts wherein a valve push rod guide is located upon the guide fingers, and 
     FIG. 7 is a detail sectional view taken along Section  7 — 7  of FIG.  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiment of a valve lifter guide in accord with the invention which is of the simplest construction is shown in FIGS. 1-5. With reference to FIG. 1, the valve lifter guide is generally indicated at  10 . The guide  10  includes an elongated central body  12  of a thin plate type configuration having parallel lateral sides  14 , and the length of the body  12  is defined by ends  16 . Holes  18  are formed in the body  12  to permit the valve lifter guide to be mounted upon an internal combustion engine as later described. 
     A plurality of resilient cantilever supported fingers  20  homogeneously extend from the body lateral sides  14 . As will be appreciated from FIGS. 1-3, the width of the fingers  20  are defined by the parallel finger edges  22 , and the end of each finger is defined by a free end  24 . As will be appreciated from FIG. 2, the length of alternate fingers defined upon a common body lateral side  14  varies. This difference in the length of the fingers is to accommodate the differences of the location and orientation of the valve lifter bores and valve lifters on the engine block as will be apparent from FIG.  5 . 
     The free end  24  of the fingers  20  is of a J-configuration, FIG. 4, defining an outer convex surface  26  which is substantially cylindrical in configuration. The convex surface  26  is uniform in configuration throughout the width of the associated finger between edges  22  of a common finger as appreciated from FIG.  1 . 
     The valve lifter guide  10  is mounted upon an internal combustion engine block  28  as shown in FIG.  5 . The engine block  28  is of the V-type having a bank of cylinders formed on each side of the central axis of the engine. Such engines usually include three or four cylinders in a bank, and in the embodiment of the guide shown in FIGS. 1-5 as there are eight fingers  20  defined upon each body lateral side  14 , and as two valve guide fingers are associated with each cylinder, the illustrated valve guide is for use with a V- 8  engine. 
     The engine block  28 , FIG. 5, includes a flat engine surface  29 , and a plurality of valve lifter guide bores  30  are formed in the engine block  28  intersecting the engine surface  29 . A roller valve lifter  32  is reciprocally located within each bore  30 , and at their lower ends, the valve lifters include rollers  34  which engage the engine camshaft as to be raised and lowered by the camshaft lobes. In FIG. 5, the camshaft is not illustrated. 
     At their upper ends, the valve lifters  32  are provided with a pair of flat orientation surfaces  36  formed upon opposite sides of the valve lifter. The surfaces  36  are parallel to each other, and intersect the valve lifter upper end  38  which engages the valve lifter rods  39  shown in FIG. 5 in dotted lines. The construction of the valve lifters is shown in greater detail in the applicant&#39;s U.S. Pat. No. 5,088,455. 
     The valve lifter guide  10  is mounted upon the engine block  28  by bolts  40 , FIG. 5, which extend through holes  18  and the cantilever supported fingers  20  will be associated with the valve lifters  32  as shown in FIG.  5 . In this relationship, the finger convex surfaces  26  will engage a valve lifter orientation surface  36  producing a linear line of contact at  42  across the entire width of the finger. Also, the finger J-shaped convex surface  26  will engage the engine surface  29  at a linear contact line  44 . The length of the fingers  20  is such that the fingers are now slightly resiliently flexed. In FIG. 5, it is to be appreciated that the long finger  20  on the right, and the short finger  20  on the left, will also be engaging valve lifters, but the valve lifters have been omitted for purpose of clarity of illustration. 
     Because the convex surfaces  26  of the fingers engage the flat orientation surfaces  36  of the valve lifters in a linear manner throughout the width of the fingers, the engagement of the fingers and valve lifters at line of contact  42  prevents rotation of the valve lifters about their longitudinal axes. 
     A variation in a valve lifter guide incorporating the inventive concepts is shown in FIGS. 6 and 7. The valve guide shown in FIGS. 6 and 7 is preferably formed of a moldable polymer by injection molding in that the configuration of the components of the valve lifter are more complex than those shown in the embodiment of FIGS. 1-5. 
     With respect to FIGS. 6 and 7, the valve lifter guide  45  includes a generally flat central body  46  having parallel lateral sides  48 . Holes  50  are defined through the body  46  to permit the guide  45  to be mounted upon an internal combustion engine, and the holes  50  may have guide members  52  located about the holes arising from the central body to facilitate installation of the guide attachment bolts. 
     A plurality of resilient cantilever supported fingers  54  are defined upon each lateral side  48 . In the illustrated embodiment, FIG. 6, six fingers are mounted upon each body lateral side in that guide  45  is used with a V-6 internal combustion engine. Each of the fingers  54  includes a free end  56  having a flat plate  58  defined thereon having a flat inner surface  60 , FIG.  7 . 
     As will be appreciated from FIGS. 6 and 7, the plates  58  include aprons  62  homogeneously extending from the edges of the plates  58 , and together, the plate  58  and the pair of aprons  62  defined upon each finger end  56 , support a rod guide plate  64 . The rod guide plate  64  includes a central circular opening  66 . The rod guide plates  64  each include an upstanding rise  68  upon which a plurality of oblique chute elements  70  are defined. As will be appreciated from the drawings, the chutes  70  are obliquely disposed to the adjacent opening  66 , and in a similar manner, the edge of the opening  66  is obliquely formed at  72 , FIG.  7 . 
     In use, the guide  45  is mounted upon an engine block in the manner shown in FIG. 5 wherein bolts  40  will extend through holes  50 . The length of the fingers  54  is such that the fingers will cooperate with the engine valve lifters to prevent valve lifter rotation. In this respect, components identical to those previously described are represented by primed reference numerals. 
     With reference to FIG. 7, the fingers  54  are of such length that the inside surface  60  of the plates  58  will engage a valve lifter orientation surface  36 ′. This engagement between the orientation surface  36 ′ and the flat surface  60  will prevent valve lifter rotation. Further, the aprons  62  are formed as to conform with the non-flattened portion of the upper ends of the valve lifters accurately positioning the finger ends  56  with respect to the associated valve lifter. Once the guide  45  is fully installed on the internal combustion engine, the guide plate opening  66  will be concentrically positioned relative to the axis of the valve lifter, and the valve lifter rods  39 ′ can be quickly inserted through the guide plate openings  66  for engagement with the upper end  38 ′ of the valve lifters  32 ′. When inserting the valve lifter rods  39 ′ through the openings  66 , the oblique chutes  70  and the opening edge  72  will tend to center the valve lifter rod with the opening  66  facilitating assembly of the valve lifter rods with the valve lifters. 
     The valve lifter guides herein disclosed may be used with internal combustion engines which do not readily accommodate the valve lifter guide shown in U.S. Pat. No. 5,088,455, and the simple construction of the embodiment of FIGS. 1-5 permit a valve lifter guide to be manufactured at a reduced cost capable of efficiently preventing valve lifter rotation. In the disclosed embodiments, bolts, such as at  40 , are used to maintain the valve lifter guides in position on the engine block. It is possible that other retainers could be used to maintain the guides in position such as resilient extensions, metal springs, or other fasteners which will firmly maintain the guides on the engine block. It is to be appreciated that the concept of the valve guides of the invention may be used with either straight or non-V-block engines even though the most desirable application for the invention is with V-block engines. 
     It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.