Honing process principle

Honing is a special form of grinding and an efficient method in finishing. This process not only removes large machining allowances (grinding was still used as polishing in the 1950s), but is also an effective machining method to improve the size, geometric accuracy and surface roughness of parts

1.1 Characteristics of honing processing

(1) High machining accuracy: especially some small and medium-sized light through holes, its cylindricity can reach 0.001mm. Some parts with uneven wall thickness, such as connecting rods, can reach 0.002mm roundness. For large holes (aperture within 200mm), the roundness can also reach 0.005mm. If there is no ring groove or radial hole and the straightness is within 0.01mm, it is also possible to grind higher precision than grinding. When grinding, the bearing supporting the grinding wheel is located outside the hole, there will be deviation, especially small hole processing, grinding precision is worse than grinding. Grinding generally can only improve the workpiece shape accuracy, to improve the position accuracy of parts, need to take some necessary measures. For example, use the panel to improve the verticality between the end face of the part and the axis (the panel is installed on the stroke arm, adjust it perpendicular to the rotating spindle, and the part can be processed by leaning on the panel

(2) Good surface quality: the surface is cross mesh, which is conducive to the storage of lubricating oil and the maintenance of oil film. It has a high surface support ratio (the actual contact area of the hole and the shaft and the ratio of the matching area between the two), so it can bear large load and wear resistance, thus improving the service life of the product. The grinding speed is low (dozens of the honing speed), and the oil stone and the hole are surface contact, so the average grinding pressure of each abrasive particle is small, so the workpiece heat is small, the workpiece surface almost no thermal damage and metamorphic layer, small deformation. Grinding surface almost no inlay and extruded hard layer. The grinding tool is in line contact with the workpiece and has a higher relative speed. As a result, high temperature will be generated in local areas, which will lead to permanent damage to the surface structure of parts.

(3) A wide range of processing: mainly processing all kinds of cylindrical holes: light through holes. Holes with discontinuity in the axial and diameter, such as those with radial holes or grooves, keyway holes, spline holes. Blind hole. Multi-step hole, etc. In addition, with special grinding head, can also be processed cone hole, round hole, but because of the complex structure of grinding head, generally do not use. Cylindrical grinding tools can be used to grind the cylinder, but the margin removed is much less than that of internal grinding. Almost any materials can be processed, especially diamond and cubic boron nitride abrasive applications. It also improves the efficiency of grinding.