JP2003071728A - Grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent chipping of a material to be ground in grinding with a rotary disk type grinding wheel, improve sharpness, and improve supply of coolant to a ground point and discharge of chip. SOLUTION: Since guide tips 4 are arranged with a space from both circumferential wall of front and rear sides of radially disposed grinding segment tips 2 in the rotating direction of the grinding wheel, the contact area of the grinding wheel with the material to be ground is made smaller for reducing friction and the sharpness is improved as compared with a conventional one having a filler for shaping filled with respect to the whole surface of a base plate. Further, since the guide tips 4 are disposed separately from the circumferential walls of the segment tips 2, the space serves as a coolant passage and a chip discharging passage, and thereby supply of coolant to the ground point and discharge of chips are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing whetstone for polishing stone materials, concrete, ceramics and the like.

[0002]

2. Description of the Related Art A polishing grindstone as shown in FIG. 5 is used as a grinding grindstone for grinding stone materials, concrete, ceramics and the like. FIG. 5A shows a polishing grindstone 20 in which a plurality of segment tips 22 made of a diamond abrasive grain layer are radially arranged on one surface of a disk-shaped substrate 21,
(B) is a polishing grindstone 30 in which a plurality of segment chips 32 radially arranged on one surface of a substrate 31 are filled with a filling shape-retaining material 33 that also serves as an impact absorbing material, and (c) is a substrate 41. A polishing grindstone 40 in which a filling shape-retaining material 43 is filled in the entire space between a plurality of segment tips 42, 42a radially arranged on one surface.

Segment chips 22, 32, 42, 42
Reference character a is an abrasive grain layer in which diamond abrasive grains are bonded by a metal bond, and has a strip shape or an oval shape. The polishing grindstone 20 of FIG. 5A is an oval segment tip 2
2 are arranged in a radial pattern, and the space between the segment chips 22 is used as a cooling water discharge part (Japanese Patent Laid-Open No. 62-62-62).
176770). The grinding wheels shown in FIGS. 2B and 2C are strip-shaped segment chips 32, 42, 4
2A is a filling shape-retaining material 33, 43 filled with a water-containing foaming material which is made to be in close contact with the peripheral wall of 2a and is made of resin, cement, ceramics or the like as a raw material, and FIG. Only the peripheral wall of 32 is filled (see Japanese Patent Publication No. 6-83963).
In (c), the filling shape retention material 43 is filled on the entire surface of the substrate 41 (see Japanese Utility Model Publication No. 6-41804).

[0004]

In the polishing grindstone 20 shown in FIG. 5 (a), there is a problem that the material to be polished is likely to be chipped due to vibration such as rattling of a polishing machine or impact at the time of contact with the material to be polished. There is. Polishing grindstone 3 of (b) and (c) of FIG.
Nos. 0 and 40 are improvements made to solve such problems, and high-viscosity resin containing stone powder or cement containing a rubber foaming agent is used as a filling shape-retaining material 33, 43 on the peripheral wall portion of the segment chip 32 or the entire surface of the substrate 41. It is filled to increase the contact area with the material to be polished.

However, the grinding wheel 30 shown in FIG.
In addition, since the filling shape retention material 33 is in close contact with the peripheral wall of the segment tip 32, the sharpness of the segment tip 32 is impaired and the supply of cooling water to the polishing point is also deteriorated. Further, the vibration of the filling shape retention material 33 is propagated to the segment tip 32, and chattering occurs in the material to be polished when processing with the segment tip 32. In the polishing grindstone 40 of FIG. 5C, since the filling shape-retaining material 43 is filled on the entire surface of the substrate 41, the contact area with the material to be polished is too large, the resistance is large, and the sharpness is reduced. Further, the supply of cooling water to the polishing point is poor, and the discharge of chips is also poor.

The problem to be solved by the present invention is to prevent chipping of a material to be polished when polishing with a rotary disk type polishing grindstone, improve sharpness, and supply and cool the cooling water to a polishing point. It is to improve the powder discharge property.

[0007]

A polishing grindstone of the present invention is a polishing grindstone in which a plurality of segment chips composed of an abrasive grain layer are radially arranged on one surface of a disk-shaped substrate, and the direction of rotation of the segment chips A guide chip facing the peripheral wall on the front side or both peripheral walls on the front side and the rear side in the grindstone rotating direction is provided so as to face the peripheral wall.

In the polishing grindstone of the present invention, the contact area with the material to be polished is smaller than that of the polishing grindstone 40 of FIG. , Sharpness is improved. Further, since the guide tip is arranged away from the peripheral wall on the front side or the front side on the front side in the rotation direction of the segment tip, this gap portion serves as a passage for cooling water and a discharge passage for cutting chips, and supplies cooling water to the polishing point. And good chip discharge performance.

Here, it is desirable that the gap between the peripheral wall of the segment tip and the guide tip is 2 to 6 mm. If this gap is less than 2 mm, the passage of cooling water and the discharge passage of chips are too narrow, and good supply of cooling water and discharge property of chips cannot be obtained. If the gap is larger than 6 mm, the function of preventing the occurrence of chipping of the material to be polished and the segment chips at the time of contact with the material to be polished becomes insufficient.

A resin such as an epoxy resin, a silicone resin, a urethane resin or an acrylic resin is suitable as a main material of the guide chip. Particularly, epoxy is preferable from the viewpoint of strength and dispersibility of a filler and an abrasive, which will be described later. Resins are most suitable. A filler and an abrasive can be added to the resin as the main material. As the filler, a hollow filler of resin or glass having a particle size of 500 μm or less can be used. The addition of the filler has the effect of promoting the wear of the guide tip and facilitating the formation of the cutting edge due to the receding of the bond layer. When a hollow filler is used as the filling material, the contact area between the guide tip and the material to be polished is reduced to reduce the contact load, and the hollow portion becomes a chip pocket for cutting chips and discharge of chips. Has the effect of improving.

As the abrasive, secondary abrasive grains having an average grain size smaller than the average grain size of the abrasive grains used in the abrasive grain layer,
Abrasive grains such as silicon carbide (GC, C) and alumina (A, WA) can be used. By adding secondary abrasive grains,
There is an effect that the secondary abrasive grains that fall off during processing wear the bond layer of the abrasive particle layer and dress the abrasive particle layer while processing. If the particle size of the secondary abrasive particles is larger than the particle size of the abrasive particles of the abrasive layer, the wear of the bond layer becomes too large, and the abrasive particles of the abrasive layer are also dropped. Conversely, if the particle size of the secondary abrasive is too small, the wear effect of the bond layer cannot be expected,
It is desirable that the grain size of the secondary abrasive grains be about 1/2 to about the same as the grain size of the abrasive grain layer. The filler and the abrasive may be used alone or in combination. A suitable amount of the filler and the abrasive added to the resin as the main material is 5 to 50%. If the addition ratio is less than 5%, the above effect does not occur, and
When the content exceeds%, the strength of the guide chip itself becomes insufficient in the case of the hollow filler, and becomes hard in the case of the abrasive.

The width of the guide chip in the substrate circumferential direction is 5 to 10
It is desirable to set to mm. If this width is less than 5 mm, the flatness of the machined surface is poor, and if it is greater than 10 mm, the contact area is too large, which hinders polishing. The height of the guide tip is the same as that of the segment tip for polishing.

Here, when the segment chips for polishing are radially arranged on the outer peripheral portion and the inner peripheral portion of the substrate, the guide chips are arranged on the segment chips arranged on the outer peripheral portion. . In this case, it is preferable that the inner portion of the guide chip in the radial direction of the substrate and the inner peripheral portion of the segment chip in the radial direction of the substrate are arranged so as to overlap each other in the circumferential region of the substrate. With such an arrangement, uneven wear of the outer peripheral segment and the inner peripheral segment as viewed in the radial direction of the substrate is suppressed.

The guide chip is arranged with respect to the segment tip in such a manner that it is arranged so as to face the peripheral wall on the front side in the grindstone rotation direction of the segment tip or both the front and rear peripheral walls in the grindstone rotation direction. It can also be arranged at a position facing the inner peripheral wall and the outer peripheral wall in the radial direction of the substrate. In this case, the height of the guide chip disposed so as to face the peripheral wall on the inner side in the radial direction of the substrate is lower than the height of the segment chip or a part of the guide chip is arranged so as not to hinder the supply of cooling water. It should be open.

[0015]

FIG. 1 is a view showing a polishing grindstone according to an embodiment of the present invention. FIG. 1A is a plan view showing the arrangement of guide tips, and FIG. 1B is a view showing the guide tips of FIG. FIG.

The polishing grindstone 10 of this embodiment has a disk-shaped substrate 1 on one surface of which abrasive segment chips 2 for polishing are provided on the outer peripheral portion of the substrate, and a similar segment chip 3 for polishing is provided on the inner peripheral portion of the substrate. Respectively, and the guide tips 4 facing the peripheral wall are provided at intervals from both the front and rear peripheral walls of the segment tip 2 in the grindstone rotating direction of the segment tip 2 (indicated by arrow D in the figure), Further, it is a polishing grindstone in which a guide chip 5 is arranged at a position facing the inner peripheral wall of the segment chip 2 in the radial direction of the substrate.

The substrate 1 is a resin substrate having an outer diameter of 203 mm and a thickness of 20 mm. The segment tip 2 is formed by forming an abrasive grain layer composed of diamond abrasive grains having an average grain size of 80 μm and a metal bond into a strip shape, and has a length 4 in the radial direction of the substrate.
It is 3 mm, width 8 mm, and height 12 mm. The segment tip 3 has the same abrasive grain layer as the segment tip 2 formed in a strip shape, and has a length of 30 mm and a width of 6 m in the radial direction of the substrate.
m, height 12 mm.

The guide chip 4 has an epoxy resin as a main material, and a hollow glass filler having an outer diameter of 50 μm as a filler is added thereto at a ratio of 20% by weight with respect to the resin as the main material, and is used as an abrasive material. GC abrasive grains are added at a ratio of 10% by weight, and the length in the radial direction of the substrate is 56 mm and the width is 7 m.
m, height 12 mm. The guide chip 5 is made of the same material as the guide chip 4, and has a length of 14 mm and a width of 7 in the circumferential direction of the substrate.
mm and height 3 mm.

The guide tip 4 is arranged at a distance of 4 mm from the peripheral wall on the front and rear sides of the segment tip 2 in the grindstone rotation direction, and the guide chip 5 is arranged at a distance of 4 mm from the inner peripheral wall of the segment tip 2 in the radial direction of the substrate. I have set up.

Since the guide tip 4 and the guide tip 5 are arranged away from the peripheral wall of the segment tip 2 in this way, the portion of the gap G serves as a passage for cooling water and a passage for discharging chips, and reaches the polishing point. The cooling water supply property and the chip discharge property are improved. Further, since the inner part of the guide chip 4 in the radial direction of the substrate and the outer part of the segment chip 3 of the inner peripheral part in the radial direction of the substrate are arranged so as to overlap in the region in the circumferential direction of the substrate, the peripheral part of the substrate is Not only the segment chips 2 but also the segment chips 3 on the inner peripheral portion of the substrate are prevented from being worn unevenly in the radial direction of the substrate, the wear of the segment chips on the outer peripheral portion and the inner peripheral portion is made uniform, and vibration of the substrate and scraping of the material to be polished are performed. Leaving can be prevented.

In the above embodiment, the guide chips 4 and 5 are arranged at the positions facing the front and rear sides of the segment chip 2 in the grindstone rotation direction and the inner peripheral wall in the radial direction of the substrate. However, the arrangement is not limited to this example, and the arrangement shown in FIG. 2 may be adopted. (A) of the figure is an example in which the guide tip 4 is arranged only on the front side of the segment tip 2 in the grindstone rotation direction,
(B) of the figure shows an example in which the guide tip 4 is arranged on the front side of the segment tip 2 in the grindstone rotation direction, and the guide tip 5 is arranged on the inner side in the radial direction of the substrate. (C) of the figure shows the guide tip 4 This is an example in which the guide chips 5 are arranged on the front side and the rear side of the segment tip 2 in the grindstone rotation direction, respectively, inside and outside in the radial direction of the substrate.

[Test Example] As shown in FIG. 1, a polishing grindstone in which segment chips 2 and 3 are arranged on a substrate, and guide chips 4 and 5 facing the peripheral wall of the segment chip 2 are arranged,
Abrasive grindstone (invention 1) in which resin: hollow filler of resin: hollow filler was added to the resin of the guide tip at a ratio of 8: 2, and GC: resin: GC: 9 A polishing process test was conducted under the following conditions using the polishing grindstone (Invention product 2) added at a ratio of 1: 1 and the conventional grinding grindstone (conventional product) shown in FIG. 5C.

[0023] Test condition   Processing machine: Automatic polishing machine for stone processing   Material to be polished: Material Granite Dimensions 800 mm x 500 mm

The test results are shown in FIGS. 3 and 4. FIG. 3 is a diagram showing sharpness, and shows power consumption, which is an index showing sharpness, as a relative index with the conventional product as 100. As can be seen from FIG. 3, the grindstones of the invention products 1 and 2 have a sharpness index improved by about 1.8 times as compared with the conventional grindstone, and in particular, the grindstone of the invention product 2 to which GC is added as an abrasive has a sharpness. Are better.

FIG. 4 is a view showing the degree of wear of the outer segment tip and the inner segment tip. The outer segment and the inner segment after being machined by using the segment tip after grinding until the residual height becomes about 8 mm. Shows the height. As can be seen from FIG. 4, in both the inner segment tip and the outer segment tip, the grindstones of the invention products 1 and 2 have the tip height after machining of about 8.2 mm, and there is no difference in height, and they are uniformly worn. Recognize. In the conventional grindstone, the inner segment tip is about 8.4 mm, but the outer segment tip is 9 mm, which shows that the segment tip is worn to the inner height. This difference in chip height causes vibration of the grindstone and uncut residue of the material to be polished.

[0026]

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

(1) By arranging the guide chips at intervals from the peripheral wall on the front side or both peripheral walls on the front side and the rear side of the grinding segment chips radially arranged in the grindstone rotating direction, the entire surface of the substrate is filled and maintained. The contact area with the material to be polished is smaller than that of a conventional grinding wheel filled with a shape material, so that the resistance is also small and the sharpness is improved. Further, since the guide tip is arranged away from the peripheral wall on the front side or the front side on the front side in the rotation direction of the segment tip, this gap portion serves as a passage for cooling water and a discharge passage for cutting chips, and supplies cooling water to the polishing point. And good chip discharge performance.

(2) By appropriately setting the gap between the peripheral wall of the segment tip and the guide tip, good supply of cooling water and discharge of chips can be obtained, and
It is possible to prevent chipping of the material to be polished and the segment chips when the material to be polished comes into contact with the material to be polished.

(3) The guide tip is made of a resin, and the filler is added to the resin to promote the wear of the guide tip, which has the effect of facilitating the formation of the cutting edge due to the receding of the bond layer. . In addition, the addition of the abrasive has the effect that the secondary abrasive grains that drop off during processing abrade the bond layer of the abrasive grain layer and dress the abrasive grain layer during processing.

[Brief description of drawings]

FIG. 1 is a diagram showing a polishing grindstone according to an embodiment of the present invention, in which (a) is a plan view showing an arrangement of guide tips;
(B) is the figure which looked at the guide tip of (a) from the A direction.

FIG. 2 is a diagram showing another arrangement example of guide chips.

FIG. 3 is a diagram showing a processing test result.

FIG. 4 is a diagram showing a processing test result.

FIG. 5 is a diagram showing an example of a conventional grinding wheel.

[Explanation of symbols]

1 substrate 2,3 segment tip 4,5 guide tip 10 Polishing whetstone D Grindstone rotation direction G gap

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3C063 AA02 AB05 BA03 BA08 BB02                       BC02 FF06 FF16 FF20

Claims (4)

[Claims] 1. A polishing grindstone in which a plurality of segment chips composed of an abrasive grain layer are radially arranged on one surface of a disk-shaped substrate, wherein a peripheral wall of the segment chips on the front side in the grindstone rotating direction or front and rear sides in the grindstone rotating direction. A polishing grindstone, characterized in that guide chips facing the peripheral walls are provided at a distance from both peripheral walls. 2. The polishing grindstone according to claim 1, wherein a gap between the peripheral wall of the segment tip and the guide tip is 2 to 6 mm. 3. The guide chip is made by adding one or both of a filler and an abrasive to a resin.
Alternatively, the grinding wheel according to item 2. 4. The polishing grindstone according to claim 3, wherein the filler is a hollow filler of glass or resin, and the abrasive is an abrasive having an average particle size smaller than the average particle size of the abrasive grains in the abrasive layer.