JPH10264041A - Lapping ultra-abrasive grain wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent partial wear of an ultra-abrasive grain wheel by partitioning an abrasive grain layer into a center part, an inner peripheral part positioned on the inside of the center part, and an outer peripheral part positioned on the outside, and making the wear resistance degree of the inner peripheral part and outer peripheral part larger than that of the center part. SOLUTION: An abrasive grain layer 13 is fixedly formed at the side face of a base metal 11. The abrasive grain layer 13 is partitioned into a center part 15 occupying a principal part, an inner peripheral part 17 positioned on the inside of the center part 15, and an outer peripheral part 19 positioned on the outside. After partitioning, the chip ratio of the center part is made 70, and the chip ratios of the inner peripheral part and outer peripheral part are respectively made 83, 85 so that the wear resistance degree of the inner peripheral part is 125 and that of the inner peripheral part is 120, in case of the wear resistance degree of the center part being 100. Wear of the inner peripheral part 17 and outer peripheral part 19 is therefore suppressed, and the flatness of the whole abrasive grain layer 13 can be maintained over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lapping super-abrasive wheel for processing a workpiece surface by sliding the abrasive layer against the surface of the workpiece, and more particularly to electric / electronic parts and various brittle materials. Lapping super-abrasive wheel suitable for high-precision machining of steel.

[0002]

2. Description of the Related Art In recent years, electric parts, electronic parts, optical parts, and the like have been increasingly improved in performance and compactness, and accordingly, high precision and high quality parts have been required. became. As a method of processing such a part, a so-called lapping processing using loose abrasives has been conventionally performed.

[0003] In the lapping process using free abrasive grains, a lapping agent, which is a mixture of abrasive grains such as diamond and a working fluid, is dispersed between a lap plate and a workpiece, and the workpiece is slid while applying pressure to both. The surface is to be finished smoothly and with high precision. Although the lapping process has low processing efficiency, a high precision of the order of 0.01 μm can be obtained, and therefore, it has been used for a long time in manufacturing and finishing processes for gauges and optical lenses.

[0004] However, since the free abrasive grains move freely without being fixed, not only is handling inconvenient, but also time and cost are required to remove sludge from the abrasive grains. As a countermeasure, a superabrasive wheel for eliminating the disadvantages of loose abrasive grains, improving processing efficiency, and facilitating handling has come to be used.

FIG. 5 is an overall view showing a conventional superabrasive wheel for lapping. Reference numeral 50 denotes a disk-shaped base metal made of a casting or an aluminum alloy, and 51 denotes a diamond or CBN or the like fixed to the side surface of the base metal. Abrasive layer made of superabrasive grains, 52 is base metal 5
0 and a through hole formed at the center of the abrasive layer 51.
In use, the surface of the workpiece is processed by sliding the abrasive layer 51 upward while pressing it against the surface of the workpiece. Alternatively, there is a method in which the upper and lower surfaces are formed as abrasive layers, and the upper and lower surfaces of the workpiece are simultaneously processed.

[0006]

The lapping process is to uniformly process a work surface of a work on the order of several μm. For this purpose, a lapping plate, that is, an abrasive surface of a lapping superabrasive wheel is used. It is important to maintain a high degree of flatness. However, in the above-mentioned conventional super-abrasive lapping wheel, as shown in FIG. 6, the outer peripheral end and the inner peripheral end are particularly severely worn during processing, and it is difficult to maintain flatness in this part. is there. Such phenomena are that large loads are likely to be applied to the inner and outer circumferences of the abrasive surface by the work and the carrier that holds the work, and that chips from the work and abrasive grains that have fallen off from the abrasive surface flow during processing to the inner and outer circumferences. It is presumed to be caused by this.

The problem to be solved in the present invention is to prevent uneven wear in a lapping superabrasive wheel by relatively simple means and to enable high-precision lapping for a long period of time.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a lapping superabrasive wheel for processing the surface of a workpiece by sliding while pressing an abrasive layer on the surface of the workpiece. Abrasion resistance is adjusted for each part of the abrasive layer. In particular, the abrasive grain layer, a central portion, an inner peripheral portion located on the inner peripheral side than the central portion, and an outer peripheral portion located on the outer peripheral side than the central portion, and the inner peripheral portion By making the degree of wear resistance of the outer peripheral part larger than the degree of wear resistance of the central part, uneven wear can be prevented.

In the present invention, the term "abrasion resistance" refers to the reciprocal of the amount of wear of the abrasive grain layer when tested under a certain condition using a wear tester. In the superabrasive wheel of the present invention, the degree of abrasion resistance is adjusted according to the portion of the abrasive layer, and in particular, the abrasion resistance of the inner and outer peripheral portions of the abrasive layer is reduced by the resistance of the central portion. By making the degree of wear larger than the degree of wear, abrasion of the inner and outer peripheral parts during use is suppressed, whereby the flatness of the entire abrasive grain layer can be maintained for a long time.

The difference between the degree of wear resistance of the inner and outer peripheral parts and the degree of wear resistance of the central part depends on the material of the work, the machining allowance and the finished surface roughness of the work. Depending on the grain size (grain size) of the abrasive grains, when the work is a general hard brittle material or quenched steel, when the wear resistance at the center is 100, the wear resistance at the inner circumference is 115-13
It is desirable to set the wear resistance of the outer peripheral portion to 115 to 135.

In order to provide such a difference in abrasion resistance between the inner peripheral portion and the outer peripheral portion and the central portion, for example, a chip rate (for grinding when the entire abrasive surface is 100%) is used. The area ratio% of the working abrasive layer chip), the kind of the bond matrix, the concentration of the used abrasive grains, the particle size of the used abrasive grains, and the addition of the hard filler can be achieved by any one or combination of these. From the viewpoint of the wear balance of the grain surface, it is desirable that the difference is caused by the difference in chip rate or the difference in concentration.

For example, when the chip rate is changed, the chip rate at the central portion is set to 70, and the chip ratio at the inner and outer peripheral portions is set to 80 to 90, so that the wear amount at the central portion is 1
In contrast to 00, the amount of wear on the inner peripheral portion can be suppressed to 130 to 140, and the amount of wear on the outer peripheral portion can be suppressed to 150 to 180.
When changing the degree of concentration, the degree of concentration at the center is set to 75, and the degree of concentration at the inner and outer peripheral parts is set to 85 to 100. The wear amount of the portion can be suppressed to 130 to 140, and the wear amount of the outer peripheral portion can be suppressed to 150 to 175.

When the degree of wear resistance of the inner peripheral part and the outer peripheral part is smaller than the above range, the abrasion of the inner peripheral part and the outer peripheral part becomes large, and the machining accuracy of the work is reduced. If it is larger than the range, the abrasive layer acts too hard, resulting in a decrease in sharpness.

Further, the width of the inner peripheral portion and the outer peripheral portion defining the abrasive grain layer varies depending on the width of the abrasive grain surface and the shape and size of the work, but when the work is a general hard brittle material or hardened steel. ,
The range of 5 to 15% of the width of the abrasive layer is desirable.

If the width of the inner peripheral portion and the outer peripheral portion is smaller than the above-mentioned range, the abrasion of the inner peripheral portion and the outer peripheral portion increases, and the machining accuracy of the work decreases. The grain layer acts too hard, resulting in a decrease in sharpness.

It is preferable that the central portion has a segment structure composed of a plurality of fan-shaped segments, and a radial slit is formed between the joining surfaces of the plurality of segments. By forming such a slit, the grinding fluid and the like containing sludge between the workpiece and the abrasive layer flow into the slit located in the rotation locus, and further, the sludge accumulated in this groove Minutes are automatically discharged to the outside by centrifugal force accompanying rotation. Further, the grinding liquid can be efficiently supplied to the grinding surface from such a slit.

Here, the width of the slit to be formed varies depending on the required processing accuracy of the work, the shape and dimensions of the work, and the like. 5 mm is desirable. If the width of the slit is less than 1 mm, the effect of discharging the grinding fluid containing sludge decreases, and if the width exceeds 5 mm, the chipping of the work and the damage of the carrier pocket are likely to occur.

For the same reason, it is desirable that either or both of the outer peripheral portion and the inner peripheral portion have a segment structure composed of a plurality of segments, and a slit is formed between the joining surfaces of the segments.

In this case, the width of the slits at the outer peripheral portion and the inner peripheral portion conforms to the central portion, but the position of each slit is
It is desirable to arrange them so as to be at the same position as the slits in the central part or almost in the middle between the slits in the central part. As a result, the grinding fluid is effectively applied to the grinding action surface, particularly at the substantially middle position between the slits in the center, because the grinding fluid is formed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a perspective view of a lapping superabrasive wheel according to an embodiment of the present invention, and FIG. 2 is a front view showing a part of the lapping superabrasive wheel shown in FIG.

Referring to FIG. 1, reference numeral 11 denotes a disk-shaped base metal made of a casting, and an abrasive grain layer 13 is fixedly formed on a side surface of the base metal 11. Further, the abrasive grain layer 13 includes a central portion 15 occupying a main portion of the abrasive grain layer 13, an inner peripheral portion 17 located on an inner peripheral side of the central portion 15, and an outer peripheral portion 19 located on an outer peripheral side of the central portion. It is partitioned.

The central portion 15 has a plurality of fan-shaped segments 15a.
And a slit S having a width of 3 mm on the joint surface side.
₁ is formed. The inner circumferential portion 17 and outer portion 19 similarly segment 17a, are formed from 19a, each segment 17a, the slit S ₂ of width 1mm on a bonding surface side of the 19a, S ₃ is formed.

As clearly shown in FIG. 2, the slits S ₂ ,
S ₃ is to be substantially intermediate position of the slit S _1, segment 17a, 19a are disposed, the slits S _1,
The arrangement is such that S ₂ and S ₃ are not continuous. By doing so, a grinding fluid is formed and the grinding fluid effectively works on the grinding surface.

As described above, the abrasive layer 13 is
When the inner peripheral portion is divided into an inner peripheral portion 17 and an outer peripheral portion 19, and the abrasion resistance of the central portion is 100, the abrasion resistance of the inner peripheral portion is 12
The chip ratio at the central portion is set to 70, the chip ratio at the inner peripheral portion is set to 83, and the chip ratio at the outer peripheral portion is set to 85 so that the degree of wear resistance at the outer peripheral portion is 0. Thereby, the inner peripheral portion 1
Wear of the outer peripheral portion 7 and the outer peripheral portion 19 is suppressed, and as shown in FIG. 3, the flatness of the entire abrasive grain layer 13 can be maintained for a long period of time. FIG. 3 is a cross-sectional view showing a state after use of the superabrasive grain wheel. In the same figure, a dashed line indicates that the central portion 15, the inner peripheral portion 17, and the outer peripheral portion 19 have the same degree of wear resistance. This shows the state of wear in the case of an abrasive wheel.

Each segment 15a, 17a, 19
Since the slits S ₁ , S ₂ , and S ₃ are formed between the workpieces a, the grinding fluid including sludge between the workpiece and the abrasive grain layer flows into the slit located in the rotation locus,
Further, sludge and the like accumulated in the slit are automatically discharged to the outside by centrifugal force accompanying rotation. Further, the grinding fluid can be efficiently supplied to the grinding action surface from such a slit.

FIG. 4 is a front view showing a part of a super-abrasive wheel for lapping according to another embodiment of the present invention, and shows a so-called continuous type super-abrasive wheel. Also in the present embodiment, the inner part is divided into a central part 15, an inner peripheral part 17, and an outer peripheral part 19, and when the abrasion resistance of the central part is 100, the abrasion resistance of the inner peripheral part is 120 and the abrasion resistance of the outer peripheral part is 120. The degree of wear resistance is set to 125.

Even in such a continuous type,
The same effect as the segment type can be achieved.Especially, even in the case of small-diameter work or hard brittle work that is easily damaged by thin objects compared to the segment type, it prevents damage to the work, carrier and abrasive surface, This has the effect of enabling efficient and high-precision machining.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A central portion 15, an inner peripheral portion 17, and an outer peripheral portion 19 of the lapping superabrasive grain wheel shown in FIGS.
A description will be given of test results on changes in abrasive grain surface accuracy and workpiece accuracy when the wear resistance is changed by changing the chip ratio or the degree of concentration.

Test Example 1 Table 1 shows a superabrasive grain wheel in which the chip ratio was changed. In Examples 1 and 2, the inner peripheral portion 17 and the outer peripheral portion corresponded to the chip ratio 70 of the central portion 15. 1
9 are 90 and 80, respectively. In Comparative Examples 1, 2, and 3, the chip ratio of the inner peripheral portion 17 and the outer peripheral portion 19 is the same as or lower than the chip ratio of the central portion 15. Table 2 shows the processing conditions, and Table 3 shows the test results. In this test, the accuracy of the abrasive surface was determined by placing the wheel on a surface plate and measuring the amount of sag (μ)
m) was measured.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

As is clear from Table 3, in Examples 1 and 2 in which the chip ratio of the inner and outer peripheral portions was made higher than the chip ratio of the central portion to increase the degree of wear resistance, the grinding surface accuracy and machining Comparative examples 1, 2, and 3 in which the chip ratios of the inner and outer peripheral portions were the same or lower than the chip ratios of the central portion, while maintaining high accuracy in both the accuracy and the abrasive surface accuracy and the processing accuracy. A decrease was confirmed. It was also found that the accuracy of the abrasive surface greatly affected the processing accuracy. Further, it was found that the wear of the entire wheel was small, and the life of the wheel was prolonged even if the wheel was continuously used.

[Test Example 2] Table 4 shows superabrasive wheels in which the degree of concentration was changed. Examples 3 and 4 show that the inner peripheral part 17 and the outer peripheral part corresponded to the concentration 75 of the central part 15. The concentration of 19 was made 100 and 85, respectively.
In Comparative Examples 4 and 5, the concentration of the inner peripheral portion 17 and the outer peripheral portion 19 is equal to or lower than the concentration of the central portion 15. Table 5 shows the processing conditions, and Table 6 shows the test results. The abrasive surface accuracy was determined by measuring the amount of sag (μm) on the inner and outer peripheral portions in the same manner as in Test Example 1.

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

[Table 6]

As is clear from Table 6, in Examples 3 and 4 in which the degree of abrasion was increased by increasing the degree of concentration at the inner and outer peripheral parts to the degree of concentration at the central part, the grinding surface accuracy and the machining Comparative Example 4 in which the degree of concentration of the inner and outer peripheral parts was the same as or lower than the degree of concentration of the central part, while maintaining high precision.
In No. 5, it was confirmed that both the abrasive grain surface accuracy and the processing accuracy decreased. In addition, when steel is generally processed, the generated cuttings are curled, the bond matrix on the abrasive surface is retreated, and wheel wear is promoted. It was confirmed that there was little wear and the life was prolonged.

Test Example 3 In the superabrasive wheel shown in Test Example 1, the chip ratio was set to 70% for the outer peripheral portion and 50% for the central portion.
% And an inner peripheral portion of 70%, the same processing was performed. As a result, the processing efficiency was improved by about 30% compared to the wheel of Example 1 without impairing the abrasive grain surface accuracy and the processing accuracy.
As a result, even when the machining efficiency is increased by reducing the degree of wear at the central portion, the predetermined degree of flatness is maintained by increasing the degree of wear at the outer peripheral portion and the inner peripheral portion relative to the central portion. I found that I could do it.

[0040]

According to the present invention, the following effects can be obtained.

(1) Adjusting the degree of abrasion resistance according to the portion of the abrasive layer, in particular, the degree of abrasion at the inner and outer peripheral portions of the abrasive layer is determined by comparing the degree of abrasion at the center. By increasing the thickness, wear of the inner and outer peripheral portions during use is suppressed, and thereby the flatness of the entire abrasive grain layer can be maintained for a long period of time.

(2) Assuming that the degree of abrasion at the center is 100, the degree of abrasion at the periphery is 115 to 130 and the degree of abrasion at the outer periphery is 115 to 135. In addition, it is possible to maintain high processing accuracy.

(3) By setting the width of the inner peripheral portion and the outer peripheral portion to be 5 to 15% of the width of the abrasive grain layer, it is possible to maintain high processing accuracy without lowering sharpness.

(4) Discharge of grinding fluid containing sludge between the workpiece and the abrasive layer by forming the abrasive layer in a segment structure and forming a slit between the joining surfaces of the plurality of segments. And the supply to the grinding action surface can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lapping superabrasive wheel according to an embodiment of the present invention.

FIG. 2 is a front view showing a part of the superabrasive wheel shown in FIG.

FIG. 3 is a sectional view showing a state after use of the superabrasive wheel shown in FIG. 1;

FIG. 4 is a front view showing a part of a lapping superabrasive wheel according to another embodiment of the present invention.

FIG. 5 is a perspective view of a conventional superabrasive wheel for lapping.

FIG. 6 is a cross-sectional view showing the state of wear of the superabrasive wheel shown in FIG.

[Explanation of symbols]

11 base metal 13 abrasive grain layer 15 a center portion 17 inner peripheral portion 19 outer peripheral portion 15a, 17a, 19a segments S _1, S _2, S ₃ slits

Claims (7)

[Claims] 1. A lapping super-abrasive wheel for processing a surface of a workpiece by sliding the abrasive layer against the surface of the workpiece while sliding the abrasive layer against the surface of the workpiece. A super-abrasive grain wheel for lapping, characterized in that: 2. The abrasive grain layer is divided into a central part, an inner peripheral part located on an inner peripheral side of the central part, and an outer peripheral part located on an outer peripheral side of the central part, and The superabrasive grain wheel for lapping according to claim 1, wherein the abrasion resistance of the inner peripheral part and the outer peripheral part is larger than the abrasion resistance of the central part. 3. When the abrasion resistance of the central portion is 100, the abrasion resistance of the inner peripheral portion is 115-130, and the abrasion resistance of the outer peripheral portion is 115-135. The superabrasive grain wheel for lapping according to claim 1 or 2, wherein 4. The width of the inner peripheral portion and the outer peripheral portion is 5 to 15% of the width of the abrasive layer.
3. The superabrasive grain wheel for lapping according to 3. 5. The wrapping device according to claim 1, wherein the central portion has a segment structure composed of a plurality of segments, and a slit is formed between joining surfaces of the plurality of segments. Super abrasive wheel. 6. A method according to claim 1, wherein one or both of the outer peripheral portion and the inner peripheral portion has a segment structure composed of a plurality of segments, and a slit is formed between joining surfaces of the segments. 5. A super-abrasive grain wheel for lapping according to claim 1. 7. The difference in the degree of abrasion is achieved by any one of a chip ratio, a kind of a bond matrix, a degree of concentration of used abrasive grains, a particle diameter of used abrasive grains, addition of a hard filler, or a combination thereof. Claim 1 characterized by the fact that
6. The superabrasive wheel for lapping according to 6.