CS272190B1 - a method of grinding flat surfaces of workpieces from super-hard materials - Google Patents

Abstract

The method of grinding planar surfaces of workpieces made of superhard materials, for example polycrystalline diamonds, polycrystalline boron nitride and the like, is performed by the circumference of a grinding wheel with simultaneous rotation of the workpiece in the grinding plane and relative oscillatory movement between the grinding wheel and the workpiece.

Description

The invention ee relates to a method for grinding planar surfaces of workpieces from superhard materials, for example polycrystalline diamonds, polycrystalline boron nitride and the like.

For grinding of superhard materials, especially for operations where it is necessary to remove a larger amount of material (surface treatment - roughing), face grinding is currently used. In these cases, either special machines or grinders are used, in which a front (pot) diamond wheel is used for the actual grinding.

The workpiece is pressed onto the front grinding surface over its entire surface, i.e. with its entire surface, which is ground.

This method (principle) of grinding requires very high pressing forces, by which the workpiece is pressed against the surface of the grinding surface of the slide (polycrystalline diamond material - PKD 30 4 80 N.mm ^-2 ; polycrystalline material of cubic boron nitride - PKKBN 2 4 8 N. mm).

The high values of pressing forces necessary for grinding superhard materials determine the construction of machines (grinders), which must therefore have the highest possible strength and rigidity.

peak grinding performances, which are currently achieved in face grinding of diamond-based polycrystals, have the highest values of grinding performances in the range Q «3 ♦ 4 mnfLmin} ·. The best grinding ratio achieved with these materials is size G «0.03 4 0.035,

These disadvantages are eliminated by the method of grinding planar surfaces of workpieces from superhard materials, for example polycrystalline diamond material, polycrystalline cubic boron nitride material and the like, according to the invention, which is performed by the grinding wheel circumference while rotating the workpiece in the grinding plane and relative oscillating movement between the grinding wheel and the workpiece.

The grinding method according to the invention makes it possible to grind superhard materials with many times 3 -1 higher parameters than hitherto known (Q 10 to 50 mm .min; G »0.03 to 0.13).

The grinding wheel and the workpiece have a linear contact, which makes it possible to achieve high specific pressures at the grinding point even on center grinders, which are difficult to achieve with the face grinding method.

In addition, the gradual approach of the edge of the abrasive grain to the grinding zone is very favorable, which is due to the tangential contact of the workpiece with the dia-wheel.

Both of these ee influences contribute to the development of the self-nourishing effect in diacodors of common bonds. This means that the slide discs do not need to be revived during grinding with any additional equipment.

In the case of the use of metal-bonded dia-disks, a high service life of the grinding wheels can be achieved with the use of anodic revitalization and with the application of the grinding method according to the invention (high grinding economies G »0.03 to 0.15).

The pressurized feed vessels grinding drawing shows where the workpiece 2 z® superhard material is in contact with the rotating disk-dia second clamping system 3 allows the rotation of the workpiece 2 ^and its current oscillation at which the workpiece 2 has its periphery extend through right and left edges bruané layer dia-discs.

For grinding workpieces made of superhard materials, we propose to use a circumferential grinding method, in which the workpiece 2 is in tangential contact with the circumference of the grinding wheel with its abraded surface, while at the same time a relative oscillating movement between the wheel and the workpiece is performed.

The proposed grinding method, which uses circumferential grinding wheels and an oscillating grinding method, can be used for the construction of special grinding machines for superhard materials and for machining these materials directly on rigid center grinders.

CS 272 190 Bl 2

Example

Grinding of polycrystals dia on a center grinder

1. Polycrystal diameter: 12 mm

2. Diameter and width of dia-disc: 250/10

3. Wheel rotation frequency: 2 090 min · '’

4. Frequency of rotation of the working headstock (polycrystal): 280 min '' ·

5. Oscillation: 35 to 45 double strokes per minute

6. Feed: 0.0025 to 0.005 mm / stroke

7. Stiffness of the machine against the feed pressure: min. 300 N

8. Cooling: 30 1 / min

9. Polycrystal circumference run-out beyond the edges of the abrasive layer: 5 mm.

The invention finds wide application in all manufacturers who are engaged in the processing of superhard materials, because it brings considerable acceleration and productivity of production.

Claims (1)

OBJECT OF THE INVENTION A method of grinding planar surfaces of workpieces made of superhard materials, for example polycrystalline diamonds, polycrystalline boron nitride and the like, characterized in that in that it is performed by the circumference of the grinding wheel while rotating the workpiece in the grinding plane and by a relative oscillating movement between the grinding wheel and the workpiece.