Mechanical lash control for a switchable roller finger follower

Patent metadata

Field	Value
Publication number	US-2016102584-A1
Application number	US-201514876039-A
Country	US
Kind code	A1
Filing date	Oct 6, 2015
Priority date	Oct 10, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

A switchable finger follower, including an inner lever and an outer lever. The outer lever is mounted for pivoting movement to the inner lever. A coupling device is located on one of the inner or outer levers and has a locking pin arranged to move between a locking position, in which the inner and outer levers are connected together for movement in an activation direction, and an unlocked position, in which the inner lever is pivotable relative to the outer lever. A coupling projection is located on the other of the inner or outer lever. The locking pin engages beneath the projection in the locking position, and the locking pin includes a flat at a defined flat height that contacts the coupling surface in the locking position and is selected from a number of locking pins having different flat heights to set a desired mechanical coupling device lash.

First claim

What is claimed is:

1 . A switchable roller finger follower having at least two lift modes for a valve train of an internal combustion engine, comprising:
an inner lever having first and second ends; an outer lever with two outer arms that extend along longitudinal sides of the inner lever, mounted for pivoting movement at the first end of the inner lever by a pivot axle; a lost motion spring connected between the inner lever and the outer lever; a coupling device located on one of the inner lever or the outer lever on an end opposite from the pivot axle that includes a locking pin arranged to move in a housing in a longitudinal direction between a locking position, in which the inner lever and the outer lever are connected together for movement at least in an activation direction of a valve, and an unlocked position, in which the outer lever is pivotable relative to the inner lever; a coupling projection with a coupling surface located on the other of the inner lever or the outer lever, the locking pin engages beneath the coupling surface in the locking position and a stop on the other of the inner lever or the outer lever contacts an opposing stop on the one of the inner lever or the outer lever; and the locking pin includes a flat at a defined flat height that contacts the coupling surface in the locking position, wherein the locking pin is selected from a number of locking pins having different flat heights to set a desired mechanical coupling device lash.

2 . The switchable roller finger follower of claim 1 , wherein the locking pin is made of hardened steel.

3 . The switchable roller finger follower of claim 1 , further comprising an anti-rotation and stop pin located in the housing that contacts the longitudinally extending flat and prevents rotation of the locking pin, and acts as a stop for the locking pin in the locking position.

4 . The switchable roller finger follower of claim 1 , wherein the coupling device is located on the outer lever, and in the unlocked position, the roller finger follower provides zero lift.

5 . The switchable roller finger follower of claim 4 , further comprising a cam follower roller connected to the inner lever by a transverse axle.

6 . The switchable roller finger follower of claim 5 , the stop is located on the inner lever and is formed by ends of the transverse axle, and the opposing stop is formed by stop projections on the outer lever.

7 . A method of adjusting a coupling device lash for a switchable roller finger follower, comprising:
providing a switchable roller finger follower having at least two lift modes for a valve train of an internal combustion engine, including an inner lever having first and second ends, an outer lever with two outer arms that extend along longitudinal sides of the inner lever, mounted for pivoting movement at the first end of the inner lever by a pivot axle, a lost motion spring connected between the inner lever and the outer lever, a coupling device located on one of the inner lever or the outer lever on an end opposite from the pivot axle that includes a locking pin arranged to move in a housing in a longitudinal direction between a locking position, in which the inner lever and the outer lever are connected together for movement at least in an activation direction of a valve, and an unlocked position, in which the outer lever is pivotable relative to the inner lever, a coupling projection with a coupling surface located on the other of the inner lever or the outer lever, the locking pin engages beneath the coupling surface in the locking position and a stop on the other of the inner lever or the outer lever contacts an opposing stop on the one of the inner lever or the outer lever, and the locking pin includes a flat at a defined flat height that contacts the coupling surface in the locking position, wherein the locking pin is a gage locking pin having a gage flat height set at a fixed dimension; measuring a lash of the coupling device between the coupling surface and the flat of the gage locking pin in the locking position; removing the gage locking pin; and selecting a locking pin with a flat height determined by using the measured lash from the gage locking pin, and installing the selected locking pin to provide a desired coupling device lash.

8 . The method of claim 7 , further comprising measuring the lash of the coupling device and confirming that the lash is in a desired range.

9 . The method of claim 8 , wherein the locking pin is selected with the flat height that results in the coupling device lash being in a range of 25 to 200 microns.

10 . The method of claim 7 , further comprising assembling a return spring, a washer, and a locking ring in the housing to retain the locking pin in position.

11 . The method of claim 7 , further comprising assembling an anti-rotation pin in the housing that contacts the flat of the locking pin.

Assignees

• Schaeffler Technologies Ag

Inventors

• Evans Matthew
• Manther Debora

Classifications

• F01L1/22 Primary

  automatically, e.g. mechanically · CPC title

• F01L2001/186

  Split rocking arms, e.g. rocker arms having two articulated parts and means for varying the relative position of these parts or for selectively connecting the parts to move in unison · CPC title

• Y10T74/20882

  Rocker arms · CPC title

• F01L2303/00

  Manufacturing of components used in valve arrangements · CPC title

• F01L2820/01

  Absolute values · CPC title