Method Of Extending Engine Service Life And Angular Displacement-Limiting Clip For Same

Abstract

A clip includes a one-piece metal body having a holder and an attached hanger. The clip is configured to couple with a valve lifter to form a lifter assembly for varying the position of a valve in an internal combustion engine. The holder may be C-shaped, and the hanger may be U-shaped. The one-piece metal body further includes an anti-scuffing outer profile, and a first and a second fillet transitioning from the holder to the hanger, for diffusing stresses induced in the clip at an angular displacement-limiting stop position defined by contact between the hanger and a wall portion of a cylinder block. Related methodology is disclosed.

What is claimed is: 
     
         1 . A method of extending a service life of an internal combustion engine comprising the steps of:
 transmitting a torque from a valve lifter rotating out of alignment with a cam to a clip, the clip having a holder engaged about a lifter body of the valve lifter and a hanger extending into a cutout formed in the lifter body;   rotating the clip concurrently with the valve lifter via the transmitted torque;   stopping rotation of the valve lifter and the clip at a stop position defined by contact between the hanger and a wall portion of a cylinder block of the internal combustion engine; and   inhibiting fatigue failure of the clip, at least in part by diffusing stresses induced in the clip at the stop position via fillets transitioning from the holder to the hanger.   
     
     
         2 . The method of  claim 1  wherein the step of transmitting further includes transmitting the torque via contacting straight sidewalls of the cutout forming a proximal channel, with a straight section of the hanger. 
     
     
         3 . The method of  claim 2  further comprising a step of maintaining clearances between arcuate sidewalls of the cutout forming a distal taper, and the fillets, during the stopping step. 
     
     
         4 . The method of  claim 3  further comprising a step of decreasing clearances between a U-shaped section of the hanger and the wall portion during the step of rotating, and wherein the step of stopping further includes stopping the rotation via reducing the clearances to zero. 
     
     
         5 . The method of  claim 4  wherein the clip includes a one-piece metal body having a uniform thickness, and each of the fillets defines a radius which is greater than the uniform thickness. 
     
     
         6 . The method of  claim 5  wherein the step of rotating further includes rotating the clip such that interference between the clip and a lifter bore formed in the cylinder block occurs predominantly at distal ends of the holder and the holder rotates without scuffing the lifter bore. 
     
     
         7 . A clip for limiting angular displacement of a valve lifter within a lifter bore formed in a cylinder block of an internal combustion engine, the clip comprising:
 a one-piece metal body including a holder, and a hanger;   the holder having a first jaw and an opposed second jaw, and a base connecting the first and second jaws, such that the holder forms a C-shape in a first plane, each of the first and second jaws including a proximal end adjoining the base, and a free distal end, and the holder further having an open side defined by the free distal ends, for clipping the holder about the valve lifter to form a lifter assembly;   the hanger projecting from the holder in a direction normal to the first plane, and having a straight proximal section connecting to the base and being positionable within a cutout formed in the valve lifter to rotationally couple the clip thereto, and the hanger further having a distal section forming a U-shape in a second plane normal to the first plane, for coupling the lifter assembly with a wall portion of the cylinder block adjacent the lifter bore; and   the one-piece metal body having an anti-scuffing outer profile configured to inhibit interference between the base and the lifter bore during rotating the lifter assembly to and from an angular displacement-limiting stop position defined by contact between the hanger and the wall portion, and the one-piece metal body further including a first and a second fillet transitioning from the base to the straight proximal section, for diffusing stresses induced in the clip at the angular displacement-limiting stop position.   
     
     
         8 . The clip of  claim 7  wherein the one-piece metal body forms a T-shape in a third plane normal to each of the first and second planes. 
     
     
         9 . The clip of  claim 8  wherein the holder includes a planar upper edge surface, and a non-planar lower edge surface, and wherein each of the first and second fillets arcs upwardly from the planar upper edge surface to the hanger. 
     
     
         10 . The clip of  claim 9  wherein each of the first and second fillets defines a radius in the third plane which is from about 2 millimeters to about 4 millimeters. 
     
     
         11 . The clip of  claim 10  wherein the radiuses defined by the first and second fillets are equal to about 3 millimeters. 
     
     
         12 . The clip of  claim 9  wherein the anti-scuffing outer profile includes a first arcuate segment defined by the first jaw, a second arcuate segment defined by the second jaw, and a linear segment defined by the base, in the first plane. 
     
     
         13 . The clip of  claim 12  wherein the linear segment is defined by a planar outboard surface of the base, and the proximal straight section further includes another planar outboard surface adjoining the planar outboard surface located on the base. 
     
     
         14 . The clip of  claim 13  wherein the one-piece metal body includes a uniform thickness which is from about 2.0 millimeters to about 3.0 millimeters. 
     
     
         15 . The clip of  claim 7  wherein the first jaw includes a first distal end surface, and the second jaw includes a second distal end surface, and wherein the distal end surfaces define an angle which is about 110° or greater, and wherein the first and second jaws each have an arcuate configuration and are mirror images of one another. 
     
     
         16 . The clip of  claim 15  wherein the holder further includes an installation assist taper narrowing in a direction opposite the direction of projection of the hanger. 
     
     
         17 . A clip for limiting angular displacement of a valve lifter, where the angular displacement is induced by engine dynamics during service of an assembly of the valve lifter and the clip in an internal combustion engine, the clip comprising:
 a one-piece metal body including a holder, and a hanger;   the holder having a first jaw and an opposed second jaw, and a base connecting the first and second jaws, such that the holder forms a C-shape, each of the first and second jaws including a proximal end adjoining the base, and a free distal end;   the holder further having an open side defined by the free distal ends, such that spreading apart the free distal ends enlarges the open side for clipping the holder about the valve lifter to form the assembly;   the hanger projecting from the holder, and having a distal section forming a U-shape, for coupling the assembly with a wall portion of a cylinder block adjacent a lifter bore in the internal combustion engine;   the hanger further having a straight proximal section connecting to the base and being positionable within a cutout formed in the valve lifter to rotationally couple the clip thereto, such that angular displacement of the valve lifter is limited at a stop position via contact between the hanger and the wall portion; and   the clip further having means, including a shape and a thickness of the one-piece metal body, for inhibiting fatigue failure of the hanger in response to stresses induced at the stop position.   
     
     
         18 . The clip of  claim 17  wherein the one-piece metal body further includes a first and a second fillet transitioning from the holder to the hanger and each having a stress diffusing arcuate shape defining a radius, and wherein the base includes an anti-scuffing outer profile configured to inhibit interference between the holder and the lifter bore. 
     
     
         19 . The clip of  claim 18  wherein the one-piece metal body includes a uniform thickness which is from about 2 millimeters to about 4 millimeters, and the radiuses are from about 2 millimeters to about 4 millimeters. 
     
     
         20 . The clip of  claim 19  wherein the uniform thickness is less than the radiuses.