JPH07246564A - Compound abrasive grain grinding wheel - Google Patents

Abstract

PURPOSE:To make the worked surface a mirror surface remaining only fine scrutches by carrying out a grinding process and a lapping process by only a grinding process, and to reduce the grinding process, by improving a grinding wheel for grinding work. CONSTITUTION:On the surface of a rough abrasive grain layer 6, a minute abrasive grain layer 3 is provided, and furthermore, about the center of the grinding wheel is made sharp so as to eliminate the run-out of the grinding wheel resulting from a vibration and the like, and a bending in the grinding work is reduced. Consequently, a mirror surface is obtained in a grinding cutting and forming grinding work, and furthermore, the number of processes is reduced and the size accuracy is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding wheel applied to precision grinding of hard and brittle materials such as ceramics.

[0002]

2. Description of the Related Art Conventionally, in processing ceramics, inorganic compounds, etc., it is a material that is hard and brittle, and is generally vulnerable to scratching, which is a characteristic of brittle materials. The processed surface is a rough surface (matte surface). It was However, in order to make the machined surface of such a brittle material into a mirror surface, generally, a metal material that is softer than the work piece after being cut into the required shape or ground, such as tin or lead, is used as a lapping plate. Although it is difficult to use lapping or to secure surface accuracy, various methods such as polishing tape, cloth wrap, etc. were used to obtain the mirror surface of the processed surface through the polishing process. .

According to the present invention, after the grinding process, the dimensional accuracy and the mirror surface of the machined surface are obtained by the grinding process only, without passing through the lapping process, the lapping process, the polishing process and the like, and a plurality of processing processes under different processing conditions. This is an invention relating to a grindstone intended for that purpose, and by using this grindstone, it is possible to easily secure dimensional accuracy and obtain a mirror surface of the processed surface.

A conventional technique will be described below with reference to the drawings. 10, 11, 12 and 13 are diagrams showing the conventional technique, and FIG. 10 is a perspective view of a conventional grindstone,
Fig. 11 is a sectional view at the initial stage, Fig. 12 is a sectional view when the tip shape is changed after using Fig. 11, and Fig. 13 shows another embodiment of a grindstone with a wide grinding surface. FIG.

In FIG. 10, reference numeral 1 is a wheel base, which is made of metal such as aluminum alloy, and 2 is a flange mounting hole machined in the center of the wheel base to which a grindstone flange is attached to a spindle shaft of a machine tool. Fix it. 3 is an abrasive grain layer, and generally abrasive grains having a grain size of # 180 to # 320 are used. The abrasive grains are metal bond, resinoid bond, or the like. And the degree of concentration of abrasive grains is generally 1
It is 00 or less and has a flat shape.

FIG. 11 is a cross-sectional view of a grindstone having a relatively thin blade, for example, for cutting. The tip shape 4 is angular immediately after manufacture, but as it is used, the corners on both sides are rounded. It shows that it will be in a state. For example, in cutting and grinding a silicon wafer such as a semiconductor, when it is cut about 1200 to 2000 times, it becomes R-shaped.

Further, in FIG. 13, the surface of the abrasive grain layer 3 is a predetermined shape (not shown) using a general grinding wheel or a forming grinding wheel.
It is a figure which shows the grindstone with a comparatively wide width which is used at the time of being shape | molded to the shape and processed into the shape. In addition, wheel base 1 '
Is thicker depending on the width of the grindstone. In addition to diamond abrasive grains, CBN abrasive grains and the like are also used in these abrasive grain layers 3. The abrasive grains having the same grain size are used.

[0008]

In the above grindstone, various grinding methods such as grinding cutting, surface grinding, and cylindrical grinding are processed by using a surface grinder, a cylindrical grinder, or various grinders. However, particularly in the case of hard and brittle materials such as ceramics, ferrite, and inorganic materials, the machined surface is satin-like and does not become a mirror surface because it is weak against scratching which is a characteristic of the material. Therefore, when machining that requires particularly high precision is required, after finishing the grinding process, the workpiece is further fixed to a jig and then lapping, polishing, etc. are performed to obtain a mirror surface of the machined surface as well as dimensional accuracy. It was also securing.

[0009]

According to the present invention, two different kinds of abrasive grains are used in the abrasive grain layer, and processing is performed by a grindstone having a coarse grain at the center and a fine grain at the outer periphery. . By doing so, cutting is performed with a coarse abrasive grain layer and processing is performed with a finer abrasive grain layer, so work efficiency is good and processing is performed with fine fine abrasive grains, so that the processed surface is finely scratched. Traces, that is, minute scratches are accumulated and a mirror surface state can be obtained.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a perspective view of a grindstone according to the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is a partially enlarged front view showing a second embodiment, and FIG. 4 is an enlarged view showing a notch portion of the second embodiment. Figure 5
Is a partially enlarged front view showing a third embodiment, and FIG. 6 is an enlarged view showing a notch portion of the third embodiment. 7 and 8
FIGS. 6A and 6B are sectional views taken along the lines AA ′ and BB ′ of the partially enlarged front views of the second and third embodiments, that is, FIGS. Further, FIG. 9 is a sectional view showing a case of a grindstone having a wide abrasive grain layer.

In FIG. 1, reference numeral 1 denotes a wheel base, which is mainly made of an aluminum alloy. 2 is a flange mounting hole. 3 is an abrasive grain layer, and the abrasive grain layer is composed of 6 coarse abrasive grain layers and 7 fine abrasive grain layers. That is, in the present application, # 2
An abrasive grain layer having a mesh of 20 or less is used as a coarse abrasive grain layer, and an abrasive grain layer having a mesh of # 250 or more is used as a fine abrasive grain layer.

That is, in FIG. 1, the abrasive grain layer 3 has fine abrasive grain layers on both sides of the coarse abrasive grain layer 6, and the tip portion (outermost peripheral portion) of the abrasive grain layer 3 has an angle of θ. (See FIG. 2) The structure is such that it reaches the fine abrasive grain layers on both sides thereof.

Incidentally, in Jis, a general mesh for classifying coarse and fine is # 220. (A coarser one is called coarse, a finer one is called fine, and more than # 600 is called extra fine.) And, as a binder, a metal bond grindstone, a resinoid grindstone, or various kinds of binders can be used. is there.

FIG. 2 is a sectional view of FIG. 1 showing this state, in which a coarse abrasive grain layer 6 is fixed to the outer periphery of the tip of the wheel base 1 and the surface portion thereof is finely abrasive. It is the grain layer 7. Then, after being hardened so as to have a predetermined width w + α, chamfering is performed from both sides at a predetermined angle with respect to the surface of the outermost peripheral portion, for example, 45 °, and a rough portion appears in the tip, and fine abrasive grains on the side surface portion The dressing 10 is applied as described above, and the both sides are further processed to remove the α dimension until the predetermined dimension W is obtained, whereby the grindstone is completed. However, the pointed tip at this time is at a position of (w + α) / 2 with respect to the width w of the grindstone. It should be noted that α is made wider than the predetermined size by the thickness corresponding to the dressing process, and is removed by dressing to have the predetermined width W and simultaneously set. At this time, it is necessary to make only the coarse abrasive grains on the sharp tip.

FIGS. 3 and 5 show a notch portion provided when a coarse abrasive grain layer is formed. FIG. 3 shows a second embodiment. The notch shape of FIG. Reference numeral 8 also widens toward the inner circumference, and as shown in FIG. 6, it has a keyhole shape. That is, a plurality of notches 8 and 9 are provided at a predetermined interval on the outer peripheral portion of the coarse abrasive grain layer, and the notches 8 and 9 are fixed to both surfaces of the coarse abrasive grain layer through these portions. By making the cutouts 8 and 9 in this way, when rotating at high speed, the fine abrasive grain layers 7 are fixed on both sides of the coarse abrasive grain layer 6 so that the fine abrasive grain layers peel off and fall off. There is nothing to do.

Further, FIGS. 7 and 8 show the sectional shape of the grindstone in this case. In the section AA 'of FIG. -B '
In the sectional view 8, fine abrasive grains are formed up to a pointed portion. For this reason, in FIGS. 7 and 8, the outermost pointed portion also has the coarse abrasive grain layers 6 and the fine abrasive grain layers 8 alternately appearing. Next, FIG. 9 shows another embodiment showing a sectional shape of a grindstone having a wide grindstone width w, and shows a state in which the tip cannot be sharpened even if the tip is chamfered at an angle of θ. Since the chamfered portion 11 cannot be made large, the tip portion has a flat portion due to the coarse abrasive grain layer.

In the thin grindstone for grinding and cutting as in these examples, it is possible to make the outermost peripheral portion sharp, but as shown in FIG. 9, a grindstone used for forming grinding, surface grinding, cylindrical grinding, or the like. In this case, since the whetstone width w is large, only partial chamfering 11 is possible. In addition, these chamfers 11 have a large wheel base, a thick and wide grindstone layer, and a thin and narrow grindstone layer. Chamfering at θ is effective.

Generally, the concentration of abrasive grains in the coarse abrasive grain layer is generally 100 or less, but in the case of the same metal bond grindstone binder, is the fineness equal to the concentration of coarse abrasive grains? Alternatively, it is desirable to increase the concentration to 100 or more. This apparently improves the hardness of the grindstone. As a result, the grinding resistance per abrasive grain can be reduced, and the maximum peripheral speed during general grinding is 18
2500 m, while it is between 00 m / min and 2000 m / min
By rotating at a high speed of / min to 3000 m / min, a more precise mirror surface can be obtained.

Next, as shown in FIGS. 4 and 6, by forming notches at a predetermined pitch on the outer peripheral portion of the grindstone, and by providing fine abrasive grain layers on the coarse abrasive grain layers on both sides, the notches are formed. A fine abrasive grain layer is also formed on the portion, and the fine abrasive grain layer does not fall off or peel off, which leads to improvement in reliability. Further, when considering electrolytic grinding, metal bond is preferable, but for mirror finishing, metal bond is used as the binder for the coarse grindstone layer, and the finer grain layer on the surface is used. By making with Resinoid Bond,
It is easy to make the processed surface a mirror surface. In this case, a grindstone made of a composite binder and a grindstone made of composite abrasive grains can be used.

Next, the outer peripheral portion of the grindstone is made by using coarse abrasive grains and is sharpened, for example, because the wheel base is thin, vibration by a machine tool, runout of the wheel, or grinding liquid supplied to the grindstone portion. When the cutting speed is unbalanced and the cutting speed during grinding is very fast, the wheel may be deformed and the grinding may not be straight. Therefore, by sharpening the tip of the coarse abrasive grains, the deformation of the wheel is prevented, and by using the coarse abrasive grains, the grinding resistance is reduced and the workability is improved. The shape of the ground surface in this case is satin-like, which is the same as that of the conventional example, but fine scratches are generated because the irregularities of the processed surface generated by the coarse abrasive grains are cut with the fine abrasive grains. A mirror surface is obtained which remains but does not affect the next process. The width L (see FIG. 7) that contributes to the processing of the fine abrasive grain layer that contributes to the processing is 0.3 m.
By setting m or more (preferably 0.5 mm or more), the surface roughness of the processed surface can be reduced, and deep scratches are less likely to enter because of processing with fine abrasive grains, that is, fine abrasive grains.

[0021]

EFFECTS OF THE INVENTION By providing a fine abrasive grain layer on top of a coarse abrasive grain layer, workability in grinding is good because it is a coarse abrasive grain layer at the cutting step, and both side surfaces thereof have fine abrasive grains. Since it is processed with grains, the surface becomes a collection of minute scratches and a mirror surface is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a grindstone according to the present invention.

FIG. 2 is a sectional view of the grindstone shown in FIG.

FIG. 3 is a partially enlarged front view of the second embodiment.

FIG. 4 is an enlarged view of a notch portion of the second embodiment.

FIG. 5 is a partially enlarged front view of the third embodiment.

FIG. 6 is a notched portion enlarged portion of the third embodiment.

FIG. 7 is a sectional view taken along the line AA ′ of the second embodiment (FIG. 3) and the third embodiment (FIG. 5).

FIG. 8 is a sectional view taken along line BB ′ of the second embodiment (FIG. 3) and the third embodiment (FIG. 5).

FIG. 9 is a cross-sectional view of a grindstone having a wide abrasive grain layer.

FIG. 10 is a perspective view showing a conventional grindstone.

FIG. 11 is a sectional view of a conventional grindstone at an initial stage of use.

FIG. 12 is a cross-sectional view after using a conventional grindstone.

FIG. 13 is a cross-sectional view of a conventional grindstone having a wide ground surface.

[Explanation of symbols]

 1 Wheel base 1'Wheel base for wide grinding wheel 2 Flange mounting hole 3 Abrasive grain layer 4 Tip shape of grindstone (before use) 5 Tip shape of grindstone (after use) 6 Coarse grain Layer 7, 9 Example of notch shape 10, 11 Dressing angle

Claims (6)

[Claims] 1. A grinding wheel for grinding such as forming, grinding and cutting, wherein two or more kinds of abrasive particles having different particle sizes are formed in layers, and the particle size is around the wheel base. A rough abrasive grain layer is provided on the inner side, fine grained abrasive grain layers are provided on both sides, and the outermost peripheral portion of the grindstone is V-shaped or inverted trapezoidal so that a cut is made in the workpiece during grinding. A composite abrasive grain grinding wheel characterized in that a coarse abrasive grain layer acts in the initial stage of, and as the cutting progresses, it is finally processed by the fine abrasive grain layers on both sides. 2. An abrasive grain layer having a coarse abrasive grain size is provided on an outer peripheral portion of a wheel base, and further an abrasive grain layer having fine abrasive grains is simultaneously provided on an outer peripheral surface portion and both side surface portions of the abrasive grain layer. In addition, the width of the fine abrasive grain layer on the wheel base is set to a predetermined grinding width, and when the outermost peripheral abrasive grain layer portion of the wheel base is V-shaped or inverted trapezoidal, both sides A composite abrasive grain grinding wheel characterized in that the outermost peripheral portion is dressed until a fine abrasive grain layer appears at the tip of the outermost peripheral portion and a coarse abrasive grain layer appears at the tip of the outermost peripheral portion. 3. A notch groove such as a U-shape or a keyhole-like shape at predetermined intervals on the outer periphery of a coarse abrasive grain adhered to the outer periphery of a wheel base at predetermined intervals. A fine abrasive grain layer passes through the groove and is fixed on both side surfaces of the coarse abrasive grain layer, and the outermost abrasive grain layer portion of the wheel base is V-shaped or inverted. A composite abrasive grain grinding wheel characterized by being shaped. 4. The outermost peripheral portion of the grindstone is composed of a coarse abrasive grain layer and a fine abrasive grain layer, and there are fine abrasive grain layers at a predetermined interval between the coarse abrasive grain layers, and the outer peripheral portion of the grindstone is coarse and fine. The composite abrasive grain grinding wheel according to claim 3, wherein the abrasive grain layers are alternately formed. 5. An abrasive grain ratio of an abrasive grain layer of finer abrasive grains than an abrasive grain layer of coarse abrasive grains of a composite abrasive grain grinding wheel has the following relationship. Coarse abrasive grain layer ≦ fine abrasive grain layer The composite abrasive grain grinding wheel according to the first, second and third aspects, wherein: 6. The composite abrasive grain grinding wheel, wherein different binders are used for the coarse abrasive grain layer and the fine abrasive grain layer, respectively. Composite abrasive grain grinding wheel.