Honing tool and fine machining method using the honing tool

Abstract

A honing tool (100) for machining an inner face of a bore in a workpiece with the aid of at least one honing operation comprises a tool body (110) that defines a tool axis (112); a first cutting group (160-1), attached to the tool body, having a plurality of radially feedable first carriers (150-1) that are feedable radially with respect to the tool axis (112) by means of an associated first cutting group feeding system (170-1), wherein each first carrier covers, on its radial outer side, a circumferential angle range of at least 20° and carries, on its outer side (154), a single first cutting material body that is wide in the circumferential direction or a plurality of narrow first cutting material bodies (140-1), which are arranged in a manner spaced apart from one another; and a second cutting group (160-2), attached to the tool body, having a plurality of radially feedable second carriers (150-2) that are feedable radially with respect to the tool axis (112), independently of the first carriers (150-1), by means of an associated second cutting group feeding system (170-2), wherein each second carrier (150-2) carries, on its radial outer side (154), a single narrow second cutting material body (140-1, 140-2). All the cutting material bodies (140-1, 140-2) of the first and the second cutting group are arranged in an axially short cutting region (130) that has a length, measured in the axial direction, which is much less than an effective outside diameter of the cutting groups with the cutting material bodies fully retracted.

1 . A honing tool for machining an inner face of a bore in a workpiece with the aid of at least one honing operation, in particular for honing cylinder surfaces in the production of cylinder blocks or cylinder liners for reciprocating piston engines, comprising:
 a tool body that defines a tool axis;   a first cutting group, attached to the tool body, having a plurality of radially feedable first carriers that are feedable radially with respect to the tool axis by means of an associated first cutting group feeding system, wherein each first carrier covers, on its radial outer side, a circumferential angle range of at least 20° and carries, on its outer side, a single first cutting material body that is wide in the circumferential direction or a plurality of narrow first cutting material bodies that are arranged in a manner spaced apart from one another; and   a second cutting group, attached to the tool body, having a plurality of radially feedable second carriers that are feedable radially with respect to the tool axis, independently of the first carriers, by means of an associated second cutting group feeding system, wherein each second carrier carries, on its radial outer side, a single narrow second cutting material body,   wherein all the cutting material bodies of the first and the second cutting group are arranged in an axially short cutting region that has a length, measured in the axial direction, which is much less than an effective outside diameter (AD) of the cutting groups with the cutting material bodies fully retracted.   
     
     
         2 . The honing tool as claimed in  claim 1 , wherein, in the case of a first cutting material body that is wide in the circumferential direction, an aspect ratio between the axial length and the width measured in the circumferential direction is  3  or less, in particular less than 1, and/or in that, in the case of a narrow first cutting material body and/or in the case of a narrow second cutting material body, an aspect ratio between the axial length and the width measured in the circumferential direction is 5 or more, in particular in the range from 8 to 25. 
     
     
         3 . The honing tool as claimed in  claim 1 , wherein the first cutting material bodies attached to a first carrier cover, with their external cutting faces, a total circumferential angle range that corresponds to at least 30% or at least 50% of the circumferential width of the outer side of the first carrier. 
     
     
         4 . The honing tool as claimed in  claim 1 , wherein each first carrier carries more than two first cutting material bodies on its radial outer side, preferably three, four, five, six or seven first cutting material bodies, and/or in that a mutual spacing between immediately adjacent first cutting material bodies lies in the order of the circumferential width of the first cutting material bodies or less. 
     
     
         5 . The honing tool as claimed in  claim 1 , wherein at least one second carrier is arranged between first carriers that are adjacent in the circumferential direction. 
     
     
         6 . The honing tool as claimed in  claim 1 , wherein the first carriers and the second carriers are arranged in a manner distributed irregularly in the circumferential direction. 
     
     
         7 . The honing tool as claimed in  claim 1 , wherein the first cutting material bodies are shorter in the axial direction than the second cutting material bodies, wherein preferably an axial length of the first cutting material bodies is less than 80% and/or more than 50% of the axial length of the second cutting material bodies. 
     
     
         8 . The honing tool as claimed in  claim 1 , wherein the honing tool has an integrated joint for coupling the tool body, with limited movability, to a connection piece, wherein preferably an axial spacing (AB) between an articulation point of the joint and a spindle-remote end of the cutting region is smaller than the effective outside diameter (AD) of the cutting groups with the cutting material bodies fully retracted. 
     
     
         9 . The honing tool as claimed in  claim 1 , wherein the second cutting material bodies are mounted in an elastically resilient manner with regard to the tool body, wherein preferably the second carriers have, close to or next to a second cutting material body, an elastic portion with cutouts (A) and spring elements (FE) formed integrally with the carrier. 
     
     
         10 . The honing tool as claimed in  claim 1 , comprising a guide group having a plurality of guide strips distributed around the circumference of the tool body, wherein preferably the guide strips are arranged only within the cutting region. 
     
     
         11 . The honing tool as claimed in  claim 10 , wherein one, a plurality or all of the guide strips are arranged immediately next to a second carrier, wherein preferably a circumferential spacing between a second carrier and the guide strip is less than the width of the guide strip in the circumferential direction. 
     
     
         12 . The honing tool as claimed in  claim 1 , wherein the first cutting group feeding system and/or the second cutting group feeding system has an axially displaceable feeding element, which has a first conical portion and a second conical portion axially offset therefrom, wherein the first carriers and/or the second carriers have, on their radial inner side, two axially offset inclined faces that are configured to cooperate with the first and the second conical portion. 
     
     
         13 . A fine machining method for machining the inner face of a bore in a workpiece, in particular for fine machining cylinder surfaces in the production of cylinder blocks or cylinder liners for reciprocating piston engines,
 wherein the fine machining method comprises at least one honing operation, in which an expandable honing tool is moved back and forth within the bore in order to create a reciprocating movement in the axial direction of the bore and at the same time is rotated in order to create a rotary movement superimposed on the reciprocating movement,   wherein,   during the honing operation, a honing tool having the features of at least one of the preceding claims is used.   
     
     
         14 . The fine machining method as claimed in  claim 13 , wherein a honing operation is carried out as a multistage honing operation, wherein, in a first honing stage, a first cutting group is pressed against the bore inner face and a bore shape that differs from a circular-cylindrical shape and is preferably rotationally symmetric is created by means of the first cutting group, by means of axially irregular material removal, starting from an initial shape, and in that subsequently, in a second honing stage, a second cutting group is fed and, by means of the second cutting group, a desired surface structure is created on the bore inner face substantially without changing the macro shape of the bore. 
     
     
         15 . The fine machining method as claimed in  claim 14 , wherein honing is carried out with path control in the first honing stage and/or is carried out with force control in the second honing stage.