Honing process principle

(1) Honing is to use one or more oil stones installed on the circumference of the grinding head. The oil stone is expanded radially by the expansion mechanism (rotary type and push type), so that the honing is pressed towards the bore wall of the workpiece, so as to produce certain surface contact. At the same time make the honing head rotation and reciprocating motion, the parts do not move; Or the honing head is only rotating, the workpiece reciprocating movement, so as to achieve honing.

(2) In most cases, the grinding head is floating between the machine tool spindle or between the honing head and the workpiece fixture. In this way, the honing head is guided by the workpiece hole wall during processing. Therefore, the machining accuracy is less affected by the precision of the machine tool itself, and the formation of the hole surface basically has the characteristics of the creation process. The so-called creation process is the formation of the hole wall and the surface of the oil stone and the hole wall by mutual grinding and mutual trimming. The principle is similar to the principle that two flat plates in plane motion grind each other to form a plane.

During honing, because the grinding head rotates and reciprocates or the grinding head rotates the workpiece reciprocates, the machining surface forms a cross helix cutting track. Moreover, the number of revolutions of the grinding head in each reciprocating stroke time is not an integer, so between two strokes, the honing head relative to the workpiece is staggered at a certain Angle in the circumferential direction. Such movement makes the movement of each abrasive particle on the hole wall will not be repeated. In addition, with each turn of the honing head, the cutting track of the oil stone and the previous turn has a certain overlap length in the axial direction, making the connection between the front and back honing tracks smoother and more uniform. In this way, every point of the hole wall and the stone face has an equal chance of interfering with each other throughout the honing process. Therefore, with the process of honing, interference points are produced on the surface of the hole and the surface of the oil stone. The interference points are honed and more interference points are produced. As a result, the contact area between the hole and the surface of the oil stone is increased, the degree of mutual interference and cutting effect is reduced, and the roundness and cylindricity of the hole and the oil stone are also improved.

Finally, the creation process of the pore surface is completed. In order to obtain better cylindricity, parts are often turned around or the axial position between the grinding head and the workpiece is changed during honing if possible.

It should be noted that because diamond and cubic boron nitride abrasive are used in honing the honing stone, the honing wear of the honing stone is very small, that is, the amount of workpiece dressing of the honing stone is very small. Therefore, the accuracy of the hole depends to some extent on the original accuracy of the sharpstone on the grinding head. So when we use diamond and cubic boron nitride sharpstones, the sharpstone should be well trimmed before honing to ensure the accuracy of the hole.