JPH11239979A - Rotary grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of the unpolished part without repeatedly making reciprocating motion while dislocating a locus of a rotary grinding wheel by forming grooves continuing in the circumferential direction so as to be dislocated from a concentric circle. SOLUTION: A rotary grinding wheel 10 is formed by fixing an abrasive material layer 13 to the surface of a plastic disk-shaped base so that spiral grooves 11 and a large number of radial grooves 12 turning to the outer peripheral part from a central hole 14 are formed in the abrasive material layer 13. A spiral shape is set so that the grooves do not exist at the same radial point separate by 180 degrees from a certain one point of these continuous spiral grooves 11. In the rotary grinding wheel 10, since the circumferential directional grooves 11 are formed in a spiral shape in this way, the spiral grooves 11 do not overlap in the circumferential direction when rotating the rotary grinding wheel 10, so that the abrasive material layer 13 contacts with the whole surface of the work object part to thereby prevent the occurrence of the linear unpolished part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary grindstone for polishing a workpiece surface by rotating and sliding while pressing an abrasive layer on the surface of the workpiece.

[0002]

2. Description of the Related Art Conventionally, rotary grindstones have been widely used for polishing the surface of hard materials such as stones, glass, ceramics and other hard and brittle materials. The basic structure of a rotating grindstone is one in which an abrasive layer is fixed to the surface of a disk-shaped substrate such as a plastic material having flexibility, and a surface fastener is fixed to the back surface of the substrate. It is mounted on a surface fastener of a grindstone table attached to a rotating shaft of a power tool main body, and is polished by rotating and sliding an abrasive layer on a surface of a workpiece.

FIG. 5 is a front view showing the surface of an abrasive layer of a conventional rotary grindstone disclosed in Japanese Utility Model Publication No. 6-1327, in which a large number of concentric grooves 51 and radial grooves are formed on the surface of a plastic disk-shaped substrate. The abrasive material layer 53 forming 52 is fixed, and a surface fastener is fixed to the back surface of the substrate. Reference numeral 54 denotes a mounting hole formed at the center.

To use the rotary grindstone 50, as shown in FIG. 6, a grindstone base 56 is attached to a grinder body 55, and a surface fastener 58 on the back surface of the rotary grindstone 50 is pressed against a surface fastener 57 of the grindstone base 56. Attach and grind the work surface by rotating and sliding while pressing the abrasive material layer 53 against the work surface. When the abrasive material layer 53 is rotated and slid, cooling water or the like containing sludge between the workpiece and the abrasive material layer 53 flows into the grooves 51 and 52 located in the rotation trajectory. , 52 are automatically discharged to the outside by the centrifugal force accompanying the rotation. Conversely, such grooves 51, 52
, It is also possible to efficiently supply the cooling liquid to the working surface.

[0005]

However, in the conventional rotary grindstone as shown in FIG. 5, since a concentric groove is formed in the abrasive layer in the circumferential direction, a work piece corresponding to this groove is formed. A linear unpolished portion occurs in the portion. In order to eliminate the unpolished portion, the reciprocating motion must be repeated while shifting the trajectory of the rotating grindstone at a pitch corresponding to the width of the unpolished portion.

On the other hand, recently, in order to improve the machining efficiency, a rotary grindstone is attached to an industrial robot or an NC machine from manual machining using a conventional electric tool or the like to machine a concave curved surface or a convex curved surface. Became. When processing is performed by a robot or an NC processing machine, a trajectory matched to a curved surface is taught by a controller to perform automatic processing.

In such automatic machining, when a rotary grindstone having a concentric groove as shown in FIG. 5 is used, the repetition trajectory of the rotary grindstone is designated so that the above-mentioned unpolished portion is not generated. For this reason, it is necessary to increase the number of teaching points, and there is a problem that it takes time and effort to increase the memory of the controller. Further, there is a problem that the processing time is prolonged and the life of the grindstone is shortened.

On the other hand, in the field of a segment type rotary grindstone for grinding of a type different from the rotary grindstone for polishing which is the object of the present invention, as shown in FIGS.
There is known a rotary grindstone in which grooves formed in an abrasive layer are formed as a large number of radial grooves extending from the inside of the base metal to the outside, and grooves are not formed continuously in the circumferential direction. FIG. 7A shows that a number of grooves 62 extending from the inside of the base metal to the outside are formed in each segment 61.
(Japanese Patent Laid-Open No. 60-242975)
FIG. 7B shows a rotary grindstone in which a plurality of convex ridges 64 and concave grooves 65 extending from the inside to the outside of the base metal are formed in each segment 63 (Japanese Patent Laid-Open No. 63-1167).
No. 47).

[0009] However, in the case of the rotary grindstone for polishing which is the object of the present invention, when such a grindstone having no circumferentially continuous groove is formed, the cooling water supply efficiency becomes extremely small. As a result, the discharge efficiency of the chips deteriorates, and the chips are left in the grooves so that processing cannot be performed. In addition, since the flexibility of the grindstone is reduced and the contact area with the curved processing surface is reduced, there is a problem that the processing efficiency and the processing quality are significantly reduced, and it is not particularly suitable for surface polishing of a curved surface of a stone or concrete. .

Further, in a cup wheel type grinding wheel different from the grinding wheel for polishing which is the object of the present invention, a rotating wheel having a perfect circular diamond wheel eccentrically attached to the top surface of a base metal (Japanese Patent Laid-Open No. Sho 62). Japanese Patent Application Laid-Open No. Hei 2-18874) and a rotary grindstone in which lattice-like grooves are formed in an abrasive coating layer.
-24063).

However, even when such a single circular abrasive grain layer or a grid-like abrasive layer is applied to the polishing grindstone of the present invention, the supply efficiency of the cooling water becomes extremely small. As a result, the discharge efficiency of the chips deteriorates, and the chips are left in the grooves so that processing cannot be performed.

The problem to be solved by the present invention is that in a polishing grindstone having circumferentially continuous grooves formed in an abrasive material layer, unpolished residue is produced without repeatedly reciprocating while shifting the locus of the grindstone. There is not to be.

[0013]

SUMMARY OF THE INVENTION The present invention is characterized in that, in a polishing grindstone having circumferentially continuous grooves formed in an abrasive portion, the circumferentially continuous grooves are formed so as to be shifted from concentric circles. I do.

Here, in order to shift the circumferentially continuous groove from the concentric circle, the groove can be formed in a spiral shape. In this case, a spirally continuous groove is formed from the through hole at the center of the abrasive layer toward the outer periphery. Radial grooves can be formed at appropriate intervals in the space between the spiral grooves. This radial groove may be straight or curved,
Also, they need not necessarily be continuous in the same direction.

By eccentrically arranging a plurality of circumferential grooves from the center of the abrasive layer, circumferentially continuous grooves can be formed so as to be shifted from concentric circles. In this case, the amount of eccentricity is set to 1/2 or more of the groove interval. Eccentricity is 1 of groove interval
If it is less than / 2, the grooves overlap in the circumferential direction when the grindstone is rotated, and if the eccentricity exceeds the groove interval, the balance when the grindstone rotates is deteriorated and abnormal vibration occurs, which is not preferable. Also in this case, a radial groove can be formed in a space between the circumferential grooves.

Further, in order to shift the circumferentially continuous groove from the concentric circle, the groove may be formed not in an annular shape but in an annular shape including a straight line. Specifically, the planar shape of the groove is a continuous triangular or octagonal polygonal groove. In this case, the planar shape of the abrasive layer and the substrate to which the abrasive layer is fixed are also polygonal. Of course, also in this case, a radial groove can be formed in the space between the annular grooves.

By displacing the circumferential grooves from the concentric circles, the grooves do not overlap in the circumferential direction when the grindstone is rotated. No linear residue is generated.

The width of the groove formed in the abrasive layer varies depending on the material of the workpiece, but is particularly preferable when a hard or brittle material such as stone or concrete and a convex or concave curved surface is machined. It is desirable to set it in the range of 7 to 2.0 mm. If the groove width is less than 0.7 mm, the supply and discharge of the cooling liquid and the discharge of the chips are not sufficient, while if the groove width exceeds 2.0 mm, the life of the grinding wheel is shortened, and The frequency of tool replacement increases, and machining time loss easily occurs.

In the polishing grindstone of the present invention, the substrate can be made of a flexible material such as plastic which has been conventionally used for polishing grindstones. Conventionally used metal-coated abrasive grains such as Ni can be used. Further, as a surface fastener to be adhered to the back surface of the substrate, a velvet type fastener or the like which has been conventionally used can be used.

[0020]

FIG. 1 is a front view of a rotary grindstone according to a first embodiment of the present invention. The rotating grindstone of the present embodiment is formed by forming spiral grooves continuous in the circumferential direction.

The rotating grindstone 10 of the present embodiment is obtained by fixing an abrasive layer 13 to the surface of a plastic disk-shaped substrate (not shown). Spiral groove 11 and multiple radial grooves 12
Are formed.

The spiral groove 11 has a groove width of 1.5 mm, and is a single continuous groove from the center hole 14 to the outer peripheral portion. 18 from one point of this continuous spiral groove 11
The spiral shape is set so that no groove exists at a point having the same radius separated by 0 degrees. The groove width of the radial groove 12 is also 1.5 m
m, which is a curved groove extending from the center hole 14 to the outer peripheral portion.

Since the rotating grindstone 10 has a spiral groove in the circumferential direction as described above, the spiral groove 11 does not overlap in the circumferential direction when the rotating grindstone 10 is rotated. Does not come into contact with the entire surface of the portion to be processed, and there is no occurrence of a linear unpolished portion unlike the related art.

FIG. 2 is a front view of a rotary grindstone according to a second embodiment of the present invention. The rotating grindstone of the present embodiment has a plurality of circumferential grooves decentered from the center of the abrasive layer portion.

The rotating grindstone 20 of the present embodiment comprises an abrasive layer 23
Are formed so as to be eccentric with respect to the center hole 24. The groove width of the groove 21 is 1.5 m
m, the groove interval is 1.5 mm, and the amount of eccentricity between the center of the concentric groove 21 and the center of the center hole 24 is 2.0 mm.
Further, radial grooves 2 similar to those of the rotary grindstone 10 of FIG.
2 are formed.

The rotating grindstone 20 thus has a circumferential groove 2
1 is eccentric, so that when the rotating grindstone 20 is rotated, the grooves 21 do not overlap in the circumferential direction, and the abrasive material layer 23 does not come into contact with the entire surface of the portion to be processed, so that no polishing remains. .

FIG. 3 is a front view of a rotary grindstone according to a third embodiment of the present invention. In the rotary grindstone of this embodiment, the planar shape of the grindstone is hexagonal, and the grooves continuous in the circumferential direction are also hexagonal in planar shape.

The rotary grindstone 30 of this embodiment has a hexagonal planar shape of a base material (not shown) and an abrasive layer 33, and the abrasive layer 33 has a plurality of hexagonal grooves 31 and radial grooves. Groove 32 is formed. Groove width of grooves 31, 32 is 1.5m
m. In addition, 34 is a center hole.

The rotating grindstone 30 is thus provided with a circumferential groove 31.
Is an annular groove including a straight line, so that when the rotating grindstone 30 is rotated, the groove 31 does not overlap, the abrasive material layer 33 contacts the entire surface of the portion to be processed, and no polishing remains. .

The rotary grindstone 10 shown in FIGS.
20 and 30 set a backup sheet having an adhesive layer formed on the upper surface in a mold, and set diamond abrasive grains on the backup sheet.
The abrasive layer 1 is filled with a flexible phenolic resin powder and a filler, and hot-pressed using a punch having a punch shape corresponding to the shape of the abrasive layers 13, 23, and 33.
It is manufactured by integrally molding 3, 23, 33 and then attaching a hook-and-loop fastener to the back surface of the backup sheet.

The above-described rotary grindstones 10, 2 according to the present invention
According to Nos. 0 and 30, unlike the conventional rotary grindstone, it is not necessary to repeatedly perform reciprocating motion while shifting the trajectory of the grindstone, so that the time required for processing can be greatly reduced, and work efficiency is improved. In addition, since the processing can be performed with a small number of times of polishing, the life of the grindstone is greatly improved. Further, since it is not necessary to set the trajectory of the grinding stone at a fine pitch, it is possible to reduce the trouble of setting a teaching point for the trajectory control and the cost of adding a memory.

[Experimental Examples] In order to confirm the effect of the present invention, the rotary grindstones 10, 20, 30 (Examples 1, 2, 3) shown in FIGS. Whetstone 4
0 (Comparative Example) was manufactured and a polishing experiment was performed. The common specifications and polishing conditions for the rotary grindstone are as follows. Specifications of rotating grindstone ・ Outer diameter: 80mm ・ Thickness: 2mm ・ Abrasive material: Ni-coated abrasive grain Grain size # 500 Polishing conditions ・ Workpiece material: Amayama granite ・ Polishing machine: Automatic polishing robot ・ Polishing method: Wet ・ Grinding wheel rotation speed : 2700rpm ・ Cooling water amount: 600ml / min

Table 1 shows the polishing results.

[Table 1]

As is clear from Table 1, the grindstones of Examples 1 to 3 have higher grinding efficiency than the grindstones of the comparative examples, and the processing time can be reduced by 50% or more compared to the comparative examples. In addition, the life of the grindstone was improved by 55% or more compared to the comparative example.

[0035]

According to the grinding wheel of the present invention, it is not necessary to make a reciprocating motion while shifting the trajectory of the grinding wheel unlike the conventional grinding wheel, so that the time required for processing can be greatly reduced. Work efficiency is improved. In addition, since the processing can be performed with a small number of times of polishing, the life of the grindstone is greatly improved. Further, since it is not necessary to set the trajectory of the grinding stone at a fine pitch, it is possible to reduce the trouble of setting a teaching point for the trajectory control and the cost of adding a memory.

[Brief description of the drawings]

FIG. 1 is a front view of a rotary grindstone according to a first embodiment of the present invention.

FIG. 2 is a front view of a rotary grindstone according to a second embodiment of the present invention.

FIG. 3 is a front view of a rotary grindstone according to a third embodiment of the present invention.

FIG. 4 is a front view of a rotary grindstone of a comparative example used in the experiment.

FIG. 5 is a front view showing an example of a conventional rotary grindstone.

FIG. 6 is a perspective view showing how to use a rotary grindstone.

FIG. 7 is a front view showing another example of the conventional rotary grindstone.

[Explanation of symbols]

 10, 20, 30 rotary grindstone 11 helical groove 12, 22, 32 radial groove 13, 23, 33 abrasive layer 14, 24, 34 central hole 21 eccentric circumferential groove 31 hexagonal circumferential groove

Claims (4)

[Claims] 1. A grinding wheel having a circumferentially continuous groove formed in an abrasive layer portion, wherein the circumferentially continuous groove is formed so as to be shifted from a concentric circle. 2. The polishing grindstone according to claim 1, wherein the circumferentially continuous groove is formed as a spirally continuous groove from a through hole in a central portion of the abrasive material layer portion toward an outer periphery. 3. The grinding wheel according to claim 1, wherein the circumferentially continuous grooves are formed by eccentrically arranging a plurality of circumferential grooves from the center of the abrasive layer portion. 4. The polishing grindstone according to claim 1, wherein the circumferentially continuous grooves are formed as a plurality of annular grooves including straight lines.