Honing is a precision machining process mainly used to improve the inner surface quality of holes. It involves low-speed grinding of the workpiece surface using an oilstone (honing bar) embedded in the honing head to achieve high precision and excellent surface effects.
The core principle of honing is to use cross mesh formation and low-speed grinding. The specific process includes: the honing head rotates and reciprocates along the axial direction, causing the oil stone to press against the hole wall, forming intersecting spiral cutting trajectories, with an intersection angle usually ranging from 10 ° to 70 °; Due to the low grinding speed (such as steel processing at about 15-30 meters per minute) and controllable cutting zone temperature (50-150 ℃), surface residual stress and deterioration layer are effectively reduced. At the same time, high-pressure cutting fluid (such as kerosene) is used to wash the chips and cool them down.
Honing has the characteristics of wide processing range, high surface quality, and high precision. It is suitable for cylindrical holes, conical holes, etc. with diameters of 5-500 millimeters or even larger, and almost all materials can be processed; The surface roughness after processing can reach Ra=0.1~0.012 μ m, forming a cross mesh pattern that is conducive to lubrication. At the same time, the roundness and cylindricity errors can be controlled within 0.005~0.01mm, but it cannot improve the positional accuracy of the workpiece.
The honing process parameters need to be adjusted according to the material, and there are multiple variants available. The key parameters include: circumferential speed (steel 15~30 meters/min, cast iron or non-ferrous metals up to 50 meters/min or more), reciprocating speed (not exceeding 15~20 meters/min), oilstone pressure (rough honing about 0.3~0.5 megapascals, fine honing can be less than 0.1 megapascals), and honing allowance generally not exceeding 0.2 millimeters; In the evolution of technology, the application of superhard abrasive oilstones (such as diamond or cubic boron nitride) has improved efficiency and surface quality, while extrusion honing and other branches treat complex surfaces through abrasive flow media.
