US 6,578,535 B2 · Valve-deactivating lifter

Abstract

A valve-deactivation hydraulic valve lifter including a conventional hydraulic lash adjuster means disposed within a pin housing slidably disposed in a lifter body. A transverse bore in the pin housing contains opposed locking pins for selectively engaging a circumferential groove including a locking surface in the lifter body whereby the lifter body and the pin housing may be engaged or disengaged to activate or deactivate a pushrod controlling an engine valve. Ends of the locking pins are spherical so that the pins cannot become stuck in corners in the groove. The groove corner is rounded be either a positive radius or a negative radius to remove a sharp corner known to be an originating and propagating point for stress failure of the lifter body in prior art lifters. The edge of each pin and the edge of the locking surface are chamfered to prevent damage to these edges during locking and unlocking. A second surface intermediate an outer surface of the pin housing and the transverse bore is also provided. A retaining ring holding the lifter assembly together may be augmented by a spacer whose thickness is selected to yield a predetermined amount of mechanical lash in the deactivation lifter.

Claims19

Dependent claims

A valve-deactivating lifter for selectively coupling the rotary motion of a cam lobe to the reciprocal motion of a valve pushrod in an internal combustion engine, comprising:

a) a lifter body having means for following an eccentric surface of said cam lobe and having a first axial bore and having a circumferential groove including a radial wall and an axial locking surface formed in an inner wall of said first axial bore and having a chamfered edge of said axial locking surface at said inner wall of said first axial bore, said groove being in communication with an oil gallery in said engine, and said radial wall and said axial locking surface forming a conjunctive corner;
b) a pin housing slidably disposed in said first axial bore and having a transverse bore therethrough and having a second axial bore;
c) a means disposed in said second axial bore for receiving an end of said pushrod;
and
d) a pair of opposed locking pins slidably disposed in said transverse bore on opposite ends of a compressed spring and each having an outer end for selectively engaging said axial locking surface to lock said pin housing to said lifter body, each of said outer ends being generally spherically shaped and having a chamfer on an edge that engages said chamfered edge of said locking surface during locking and unlocking, each of said locking pins having a stepped flat for engagement with said axial locking surface of said circumferential groove.

2 more elements

A method for setting the mechanical lash to a predetermined desired value in a valve-deactivating lifter having a pin housing disposed in a lifter body wherein the housing is retained in the body by a retaining ring disposed in a retainer groove in the lifter body and extends radially inwards of an inner wall of said body, the pin housing having locking pins slidably disposed in a transverse bore for engaging a circumferential groove in the lifter body, said circumferential groove having a locking surface, comprising the steps of:

a) installing said pin housing into said lifter body;
b) engaging said locking pins with said circumferential groove;
c) installing said retaining ring into said retainer groove;
d) biasing said pin housing against said retaining ring;
e) measuring a clearance between said locking pins and said locking surface;
f) numerically subtracting a predetermined desired clearance value from said measured clearance to obtain a first numerical difference;
g) selecting a spacer having a thickness equal to said first numerical difference;
and
h) installing said selected spacer in said retainer groove adjacent said retaining ring to yield said predetermined desired clearance (lash) in said lifter.

6 more elements

A method for setting the mechanical lash to a predetermined desired value in a valve-deactivating lifter having a pin housing disposed in a lifter body, wherein the housing is retained in the body by a retaining ring disposed in a retainer groove in the lifter body and extends radially inwards of an inner wall of said body, the pin housing having locking pins slidably disposed in a transverse bore for engaging a circumferential groove in the lifter body, said circumferential groove having a locking surface, comprising the steps of:

a) installing said pin housing into said lifter body;
b) engaging said locking pins with said circumferential groove;
c) installing a locator ring of a known thickness into said retainer groove;
d) biasing said pin housing against said locator ring;
e) measuring a clearance between said locking pins and said locking surface;
f) numerically subtracting a predetermined desired clearance value from said measured clearance to obtain a first numerical difference;
g) selecting a retaining ring having a thickness equal to the sum of the known thickness of said locator ring and said numerical difference;
h) removing said locator ring;
and
i) installing said selected retaining ring in said retainer groove to yield said predetermined desired clearance (lash) in said lifter, whereby said housing is retainer in said body by said retaining ring.

7 more elements

Dependencies are inferred from the claim text.

Valve-deactivating lifter

Life of this patent

Valve-deactivating lifter

Life of this patent

Abstract

Claims19