Camshaft speed sensor target

Abstract

A method of constructing a speed target on a camshaft in a combustion engine is disclosed. In applying the method a multiple number of ring segments are positioned around a portion of the camshaft. The multiple number of ring segments form a closed ring having a variable outer magnetic surface for reading by a speed sensor. Further, the multiple number of ring segments are secured in a radial direction and in a circumferential direction with respect to the camshaft.

1 . A method of constructing a speed target on a camshaft in a combustion engine, comprising:
 positioning multiple ring segments around a portion of the camshaft, the multiple ring segments forming a closed ring having a variable outer magnetic surface for reading by a speed sensor; and   securing the multiple ring segments in a radial direction and in a circumferential direction with respect to the camshaft.   
     
     
         2 . A method of  claim 1 , further including:
 positioning the multiple ring segments at a specific axial position around the portion of the camshaft, between axially extending portions of the camshaft.   
     
     
         3 . A method of  claim 1 , further including:
 arranging at least two ring segments of the multiple ring segments in a relative position around a portion of the camshaft wherein an end portion of a first ring segment overlaps an end portion of a second ring segment.   
     
     
         4 . A method of  claim 3 , further including: placing at least one pin through a pair of aligned bores on the segments, the pin also passing through the bores into a bore on the camshaft and retaining the segments in place on the camshaft. 
     
     
         5 . A method of  claim 1 , further including:
 arranging at least two ring segments of the multiple ring segments in a relative position around a portion of the camshaft wherein an end portion of a first ring segment abuts against an end portion of a second ring segment.   
     
     
         6 . A method of  claim 5 , further including:
 placing at least one pin through a pair of aligned bores in the end portions of the first and second ring segment and wherein an inner surface of at least one ring segment corresponds to a machined outer surface of the camshaft portion.   
     
     
         7 . A method of  claim 1 , further including:
 removing a speed target from the camshaft prior to positioning the multiple ring segments around a portion of the camshaft.   
     
     
         8 . A camshaft system for a combustion engine, comprising:
 a camshaft; and   a speed target including multiple ring segments positioned around a portion of the camshaft, the multiple ring segments forming a closed ring having a variable outer magnetic surface configured to be read by a speed sensor, wherein the multiple ring segments are secured in a radial direction and in a circumferential direction with respect to the camshaft.   
     
     
         9 . A camshaft system of  claim 8 , wherein the speed target is positioned between two lobes on the camshaft, the lobes having a maximum outer diameter that is greater than the inner diameter of the closed ring. 
     
     
         10 . A camshaft system of  claim 8 , wherein at least one pin passes through a pair of aligned bores on two ring segments of the multiple ring segments. 
     
     
         11 . A camshaft system of  claim 10 , wherein the at least one pin includes a rivet. 
     
     
         12 . A camshaft system of  claim 10 , wherein the at least one pin includes a roll pin. 
     
     
         13 . A camshaft system of  claim 8 , wherein the multiple ring segments are secured to the camshaft via multiple pin-hole connections. 
     
     
         14 . A camshaft system of  claim 8 , wherein the multiple ring segments include two half-ring segments. 
     
     
         15 . A speed target for assembling on a camshaft of a combustion engine, comprising:
 multiple ring segments positioned around a portion of the camshaft, the multiple of ring segments forming a closed ring having a variable outer magnetic surface configured to be read by a speed sensor, wherein the multiple ring segments are secured in a radial direction and in a circumferential direction with respect to the camshaft.   
     
     
         16 . A speed target of  claim 15 , wherein the speed target is positioned between two lobes on the camshaft, the lobes having a maximum outer diameter that is greater than the inner diameter of the closed ring. 
     
     
         17 . A speed target of  claim 15 , wherein at least one pin passes through a pair of aligned bores on two ring segments of the multiple ring segments. 
     
     
         18 . A speed target of  claim 17 , wherein the at least one pin includes a rivet. 
     
     
         19 . A speed target of  claim 17 , wherein the at least one pin includes a roll pin. 
     
     
         20 . A camshaft system of  claim 15 , wherein the multiple ring segments are secured to the camshaft via multiple pin-hole connections.