JPH0224063A - Cup type grinding wheel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to diamond particles arranged symmetrically about the axis of rotation of a grinding wheel, made from diamond particles agglomerated by a metallic or organic binder, and separated by grooves. The present invention relates to a cup-shaped grinding wheel formed by a diamond-carrying element.

The invention also relates to the use of this grinding wheel for the mechanical polishing of flat surfaces of glass articles. Background of the Invention The invention is primarily applicable to the glass industry, the crystal industry and the production of ceramic articles. Ru.

The above type of grinding wheel is formed by a body supporting a working band which has an embossed form and is described in document PR-B-110.
It is known from No. 4941. The band is formed by diamond-bearing elements made of diamond particles agglomerated with a metallic or organic binder, which diamond-bearing elements can be square, parallelepiped, rhomboidal, hexagonal, or irregular. They are divided by grooves to have a regular shape. The profile, shape, and dimensions of this grinding wheel are very variable, and the grain size depends on the type of operation the wheel is expected to perform, from free-grinding to reflective grinding.

However, this document only mentions an example of fine-grained diamond, which is a particle on the order of 180 microns. For particle fineness smaller than 100 microns, there is a risk of excessive flaking of the fine particles, which may fall off the coating before being completely worked.

Document BE-A-905.292 discloses a mechanical process for polishing the plane of the glass article, which is placed in rotation about an axis perpendicular to the plane. This process utilizes the abrasive crown of a rotating grinding wheel, which rotates about an axis that is offset relative to a geometric axis by a distance less than the radius of the crown; The axis of rotation of this crown is then parallel to its geometric axis and parallel to the axis of rotation of the object to be treated.

Glass, crystal or ceramic articles (for example drinking glasses, vases, ash pits or other objects or objects preferably made of mineral material with a radius of curvature greater than Ie)
A sweeping motion of the surface to be processed by a grinding wheel rotating under constant pressure along a flat or curved surface results in a perfect polish without creating streaks. If the particles are fine enough, the grinding wheel will restore the luster of a glass crystal or ceramic item that has lost its luster due to previous grinding operations. However, it has the disadvantage of including a band of abrasive material mounted eccentrically on the crown of the grinding wheel.

Document BE-A-08700437 discloses a method for mechanically polishing the flat surface of a glass article by means of a cup-shaped grinding wheel whose flanks are provided with bands of abrasive material, which grinding wheel is used during polishing. It is rotated about an axis inclined with respect to the axis of rotation of the surface to be polished by pressing it against the object to be polished along the generatrix of contact under an appropriately constant pressure. This device allows a sweeping motion at each point of the surface being treated so that a well-defined path depth is achieved. The sides of this cup-shaped grinding wheel are removable held by supports made of compressible elastic material mounted eccentrically with respect to the geometric sleeve of the grinding wheel by a distance less than the average radius of the sides of the grinding wheel. A band is provided, the axis of rotation of which is inclined to the geometrical axis and to the axis of rotation of the surface to be treated. Thus, along the contact generatrix between the object to be polished and the grinding wheel, a limited contact surface is created which allows very localized heating on the surface to be polished during polishing; As a result, microscopic melting occurs on the polished surface.

This process, like the previous one, has the disadvantage of involving a removable band of abrasive material mounted eccentrically on the crown of the grinding wheel. This eccentric weight is balanced with respect to the rotation axis of the grinding wheel by an unbalance member attached to the grinding wheel. During use of this grinding wheel, and due to the wear exerted on the band, it is observed that the equilibrium becomes progressively worse and increasingly unfavorable vibrations occur.

(Summary of the invention) The present invention seeks to overcome the above-mentioned disadvantages.

It extends symmetrically with respect to the axis of rotation of the grinding wheel and comprises a coating formed of diamond-bearing elements made of diamond particles agglomerated by a binder of metal or grain body, said diamond-bearing elements being formed by grooves. the abrasive coating or at least a portion of the surface of the grinding wheel;
A feature of the invention proposing a cup-shaped grinding wheel characterized in that it consists of diamond particles having a size between belongs to

According to another feature of the invention, the groove has a width of between 0.5 and 4 mm, preferably 2 mm. So, the depth is 0.
It is preferably between 5 and 21, preferably Inn.

In a particular embodiment, the grooves are perpendicular to each other and form a square with sides of about 4 to 12 au, preferably 6 mm. This groove may have a width of between 1 and 3 mm and a depth of between 0.5 and 2 mm.

Grooves are generally provided in the abrasive coating of a grinding wheel for roughening the surface of hard materials, ie, in an abrasive coating formed by relatively coarse particles. On the other hand, known grinding wheels for finishing operations are generally equipped with fine particles or with a metallic or resinous binder fixed on an elastic support, as described in European Patent Application No. 793027921. The surface of the abrasive material is similar to that of the abrasive material with diamond-supported aggregates containing diamond-bearing aggregates.

Therefore, as claimed, an embossed abrasive coating fixed directly to the body of a cup-shaped grinding wheel provides a better surface finish than an abrasive coating unevenly distributed on the surface of the grinding wheel. It's amazing what it brings.

The grinding wheel according to the invention allows surfaces of glass or more or less rough mineral materials to be finished, which surfaces are free from the roughest scratches, for example blade marks, deflections or removal of punches in the case of castings. The surface is roughened and/or shaped beforehand to remove scratches.

The invention also relates to the use of a grinding wheel as described above for the mechanical polishing of flat or substantially curved surfaces of glass articles.

In the case of a cup-shaped grinding wheel with cylindrical flanks, the grinding wheel is left to rotate about an axis that is clearly perpendicular to the axis of rotation of the surface. On the other hand, if the grinding wheel has frusto-conical or spherical segment-shaped side surfaces, then during the grinding operation, the grinding wheel is applied along a part of the contact surface against the object to be polished under a suitable constant pressure. The wheel is positioned so as to rotate about an axis that is oblique to the axis of rotation of the surface in order to mechanically polish the spherical surface. Grinding wheels are typically rotated about an axis of rotation at speeds on the order of 1800 to 400 rpm.

The present invention allows for the conversion of existing equipment without expense to carry out the process described above.

The mechanical polishing method using a grinding wheel according to the present invention can be easily automated. It allows combining the roughening, shaping and polishing of surfaces made of mineral materials, and these various operations are distributed over different machines equipped with devices for transfer from one machine to another. or the sharpening working stations are combined into a single machine arranged in series to receive the objects to be processed in succession. This material is fed continuously and the tasks described above are performed by robots.

The grinding wheel according to the invention facilitates the production of complete optical polishes by a fully automated process and allows the continuous mechanical production of glass or crystal surfaces that could hitherto only be produced by manual and empirical processes. .

(Example) Next, one embodiment of the present invention will be described with reference to the drawings.

In the following drawings, the same reference symbols indicate the same or similar elements.

As shown in FIG. 1, the cup-shaped grinding wheel, generally designated by the numeral l, is designed to form a uniform annular abrasive surface symmetrically disposed about the axis of rotation LL' of the grinding wheel l. For example, electrolytic de-posit
It has an annular crown 2 with an abrasive coating 3 on its upper surface 4 secured by a ion.

The abrasive coating 3 is formed by fine particles of diamond agglomerated with a metallic or organic binder. According to the present invention, the diamond particles are between about 1 and 100 microns in size and belong to one of the following particle size analysis categories:

15-30 microns 10-20 microns 6-12 microns 4-8 microns 3-6 microns During operation of the grinding wheel, the T-shaped grooves 5 which promote the wet condition are
It is provided on the abrasive coating 3. In a particular embodiment, the grooves 5 are arranged symmetrically with respect to the axis of rotation LL' of the grinding wheel, they are perpendicular to each other and are, for example, square with sides of between about 4 and 12 mm, preferably with sides of 6 mm. It forms a square. Groove 5 is about 0.5 to 4 m
It may have a width of between about 0.5 to 21 m and a depth of about 0.5 to 21 m.

The diamond-bearing crown 2 is, for example, 10 and 4On+
2 m (preferably 30 mm) and are joined by intersecting grooves 5, preferably having a width of about 2 mn+ and a depth of about 1 mm.

The grinding wheel in FIG. 1 can be used, for example, to grind flat surfaces of objects made of glass, crystal or ceramic materials.

FIG. 2 shows the surroundings of the flat base IO of the grinding wheel and glassware in FIG. The IO being processed is kept in contact with the abrasive coating by some means at all times. The contact zone is hatched in FIG. 2 and designated by the reference numeral 11. The grinding wheels are rotated about an axis LL' parallel to the axis of rotation SS of the grinding wheels 10 to be treated, and their surfaces 10 are perpendicular to each other in order to cover the entire surface 10 to be polished while maintaining a constant pressure. is swept. Sweeping is performed extremely wet.

The grinding wheel according to the present invention also has the following features:
For example, it has an abrasive coating on the oblique sides forming a frustoconical surface or on curved surface segments created by rotation.

FIG. 3 shows a schematic example of a machine using a grinding wheel according to the invention (a Maxi-Fret Q machine manufactured by Hibuick Q), the abrasive coating of which covers a frusto-conical side surface 2.

The machine shown in Figure 2 has a rotating holding head 18 driven by a drive motor 21 and a grinding wheel which is rotated during polishing so that the article is pressed against the grinding wheel under suitably controlled air pressure. It has a holding head and means for transporting the articles 7 towards the vehicle 1. Finally, the cup-shaped grinding wheel is mounted on the floating shaft 8 of the electric motor, as described in Belgian patent no. 696.828.

The article 7 with the surface to be treated IO is held on a holding plate 18 which is rotated by a shaft 20 of a motor 21, for example in the direction of the arrow X about an axis of rotation SS' perpendicular to the surface to be treated. This surface 10 is placed parallel to itself in contact with the diamond-bearing crown 2 of a frusto-conical abrasive-coated 3° rotating grinding wheel 1, which crown 2 is inclined in this example with respect to the axis SS°. It rotates around the geometric axis LL'. this crown 2
is rotated about axis LL' in the direction of arrow Y. The speed and direction of rotation of the surface 10 to be treated and the diamond-bearing crown 2 may be the same or different.

The drive motor 21 for rotating the object 7 is controlled by fluid pressure. The speed is changed from I to 4 by the speed adjusting means.
It can be changed steplessly between 0rpI11. Software (not listed here)

) by item 7. Grinding wheel 1. Progress of the grinding wheel.

The pressing of the diamond-bearing crown against the item 7 allows pressure to be controlled and programmed.

The grinding wheels are forced to sweep perpendicularly to each other in order to cover the entire surface being polished.

This sweeping action is performed in extremely wet conditions.

The magnitude of this sweeping motion is of the order of 10 to 100+ m, preferably 40 mm. Each point of the surface 10 to be treated is therefore in contact with the abrasive coating of the crown 2 of the grinding wheel due to the rotational movement of the surface 10 and the grinding wheel l.

A substantially constant pressure is applied by the diamond-bearing crown 2 to the surface IO during processing. This constant pressure is
As described in Belgian Patent No. 696.828, it is provided by a floating shaft 8 which is subjected to a thrust force generated by the fluid.

The abrasive crown has an outer diameter of 100 to 250 alI, preferably 150 mm. The abrasive cover 3 has a width of 10 to 40+i, preferably 30 m, an outer diameter of 150 mm and an inner diameter of approximately 90 mm.

FIG. 4 shows a machine similar to the one shown in FIG. It extends over the side surface 2 forming the .

The performance of known machines equipped with the grinding wheel according to the invention is improved and the following favorable properties are preserved:

1. Only used water input with additives, such as surfactants or other (biodegradable) additives.
Grinding wheel lubrication that allows rough machining, shaping and polishing operations to be grouped together on the same transport machine without the risk of disturbing downstream operations related to upstream operations.

2. Perfect balance of the grinding wheel and no vibration due to symmetrical wear about the rotating axis.

3. Accurate positioning of the surface to be processed for each grinding wheel.

4. Depth of machining operation at each work position (pass dep
Tight control of th).

5. Progressive reduction of the micrometer distance between the surface to be treated and the grinding wheel, and the contact pressure to allow finish honing.

6. Optimal control of the programmed reciprocating motion as a function of the rotational speed of the surface being polished and the object being polished to produce a geometrically "perfect" surface.

The results obtained with glass or crystal raw surfaces shaped into flat (or concave spherical) surfaces depend on the fineness of the diamond used. therefore,
Diamonds belonging to one of the following categories are used:

15-30 microns 10-20 microns 6-12 microns 4-8 microns 3-6 microns Diameter 1 with an abrasive coating consisting of particles with a fineness between IO and 20 microns after polishing with cerium
The results of measurements of roughness and flatness obtained on crystal samples polished with a 50 mm grinding wheel are as follows.

Ra roughness (CL A) - 4 to 6 micro-inches,
In that case, use visual brushing (opticalpol 1s).
h) is 1 micro-inch; the surface flatness is approximately 0
．． 0In++a determined by machine adjustment.

The cerium oxide polish may be applied directly by hand or automatically.

It goes without saying that the present invention is not limited to the above, and that the above may be modified without departing from the present invention.

[Brief explanation of the drawing]

FIG. 1 is a top view of a perfectly centered, diamond-bearing, annular crowned cup-shaped grinding wheel;
Figures 1 and 3 show the contact zone between the grinding wheel of Figure 1 and the plane of the base of the glass article to be polished; Figure 3 shows the invention with a perfectly centered, frusto-conical diamond-bearing coating; FIG. 4 is a scaled-down view of a polishing device using a cup-shaped grinding wheel according to the present invention, and a front view showing a motor equipped with a floating shaft to which the grinding wheel is attached. A cup-shaped grinding wheel according to the present invention is shown,
FIG. 4 is a plan view similar to that shown in FIG. 3; Patent Applicant Dearman Boat Société Anonyme Agent Patent Attorney Ao-Haku Ao-Haka 1 IG 1

Claims (9)

[Claims] (1) an abrasive coating formed by a diamond-bearing element extending symmetrically about the axis of rotation (LL') and consisting of diamond particles agglomerated by a metallic or organic binder; A cup separated by a groove, in which the abrasive coating is fixed to at least a part of the surface of the grinding wheel, and in which it consists of diamond particles with a size between 1 and 100 microns. Shape grinding wheel. (2) The abrasive coating belongs to one of the categories 15-30 microns, 10-20 microns, 6-12 microns, 4-8 microns, 3-6 microns, and has a size from 1 to 30 microns. The cup-shaped grinding wheel according to claim 1, characterized in that it is made of material particles. (3) The cup-shaped grinding wheel according to claim 1, wherein the grooves are arranged symmetrically with respect to the rotation axis (LL') of the grinding wheel. 4. The cup-shaped grinding wheel of claim 1, wherein the grooves are orthogonal to each other and have a square shape with sides measuring between about 4 and 12 mm. (5) The crown of the above abrasive material is approximately 100 to 250 m.
with an outer diameter of size between 10 and 40 m.
Cup-shaped grinding wheel according to claim 1, characterized in that it has a width of up to m. (6) The groove has a width of approximately 0.5 to 4 mm and a depth of approximately 0.5 to 2 mm. cup-shaped grinding wheel. (7) A method of using the grinding wheel according to claim (1) for mechanically polishing a flat surface of a glass article. (8) Axis (
7. The method of use according to claim 7, of a cup-shaped grinding wheel with a cylindrical side surface rotating about LL'). (9) Around the axis (LL') inclined with respect to the rotation axis (SS') of the mechanically polished spherical surface in order to press the grinding wheel against the surface to be polished under a suitable constant pressure during polishing. 8. Use according to claim 7, of a cup-shaped grinding wheel with a truncated conical side surface or a side surface formed as a spherical segment, which can be rotated.