JPS59110563A - Diamond cutting grindstone - Google Patents

Abstract

PURPOSE:To raise the reliability of the captioned grindstone on its application by respectively forming plural steps of slots into different depths on a substrate peripheral edge and attaching antifriction chips corresponding to these depths, in a grindstone for concrete cutting, etc. CONSTITUTION:Slots 12-14 differing in their depths into three steps are repetitively arranged on a substrate 11, and sintered hard alloy chips 15-17 possessing the lengths corresponding to the respective depths are brazed into the respective slots. Thereby, the substrate 11 is protected from wear, and undercutting just under a segment is prevented. Further, although a tendency is not avoided that wear is easily yielded along a circular wheel making contact with the bottom of the slots 12-14 on the substrate 11, the degree of wear concentration is reduced down to 1/3, and the width of a concentrated flow passage is substantially enlarged to three times since the wear is dispersed to three circular wheels, so that local wear is greatly suppressed. In such a manner, the possibility of rupture of the grindstone caused due to undercutting is eliminated along with the improvement of the reliability, presenting a prolonged term of endurance time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention, as shown in FIG. This invention relates to a diamond cutting whetstone constructed by attaching a diamond whetstone body (segment) to a divided circumferential portion between each slot 3, 3.

This type of diamond cutting grindstone is widely used for cutting stone, concrete, etc., grooving, etc., but there is a drawback that the substrate 1 is worn out directly under the segment S, that is, an undercut occurs. That is, initially, the thickness of the substrate 1 is constant over the entire surface, but as the area directly below the segment wears out, the thickness of the substrate 1 decreases in the area 6 that holds the segment 5, as shown in Figure 1. The grinding wheel breaks due to breakage.

As a measure to prevent undercuts, as shown in FIG. 3, a method is used in which a chip 7 made of a wear-resistant material such as cemented carbide is attached to the front side of the slot portion 3 of the substrate in the direction of rotation of the grinding wheel (arrow a). This causes wear directly under the segment 6.
However, as shown in Figure i+, abrasion 9 occurs along the circumference below the bottom edge of the chip (see Figure 9), and the problem of undercuts has not been completely solved. As the performance of the grinding wheel j has improved and its life has become longer, the wear resistance of the substrate l is relatively insufficient and the problem of undercuts has emerged.

In particular, the substrate of a grindstone for cutting concrete is thin, whereas the material to be cut, concrete, is highly abrasive, resulting in noticeable undercuts. The same applies to grindstones for cutting asphalt for road pavement.

An object of the present invention is to provide a diamond cutting wheel that prevents undercutting and can withstand normal use until the segments are exhausted. In order to achieve the above object, the present invention has been developed as follows.

It is clear that substrate wear occurs due to chips generated during the cutting process. The chips flow through a small gap between the cut surface of the material to be cut and the substrate, and the force υF exerted by the chips has a large relative speed to the high-speed rotating substrate, which causes the steel substrate to wear out. The chips generated mainly in the cage at the outermost periphery of the grinding wheel temporarily stay in the slot JIC, and then flow out into the gap between the workpiece and the substrate as described above. The parts wear out first, producing wear grooves along the outermost periphery of the substrate l. - When a groove is formed, this becomes a flow path for chips and the flow is concentrated in this groove, so the groove rapidly develops and reaches the state shown in FIG. 26.

In the cutting wheel shown in FIG. 3, the wear-resistant tip 7 reinforces the substrate and prevents the above-mentioned initial wear, which has the effect of suppressing undercuts directly under the segments. However, since there is no barrier made of wear-resistant material at the bottom 10 of the slot, a wear groove develops in this region during the layering process described above, resulting in an undercut as shown in the cross-sectional view of FIG.

As described above, undercutting occurs as a result of the flow of chips discharged through the gap between the workpiece and the substrate being concentrated along a circular ring of a constant radius on the substrate. If this concentration is avoided and the flow of chips is dispersed, undercuts will not occur. The diamond cutting grindstone of the present invention realizes this state.

FIG. S shows an embodiment of the present invention, in which the substrate llK
is a slot with three different depths/2. /3゜lt are repeatedly arranged, and each slot has a cemented carbide tip ljs of a length corresponding to the respective depth, /6. /7 is brazed. These wear-resistant tips protect the board from wear and prevent undercuts directly under the segments, which is the same as the conventional structure shown in Figure 3, but the depth of the slots is different, so the length of the wear-resistant tips is different. The difference is that it is not constant but varies in three stages.

In the present invention, there is an unavoidable tendency for wear to occur along the circular ring that is placed on the board and contacts the bottom of the slot, but this is avoided from concentrating on a certain circular ring and is spread over three circular rings. Because of the dispersion, the degree of concentration is dramatically reduced, and the width of the concentration channel is effectively increased by a factor of three, so localized wear is greatly suppressed, and until the diamond wheel segment is exhausted. Virtually no wear groove formation or undercuts are observed.

As described above, the diamond cutting grindstone of the present invention has no fear of damage due to undercuts, is highly reliable in use, and has a long service life, so it is particularly suitable for cutting concrete, asphalt, etc. This is much more advantageous than the conventional method.

In the embodiment shown in FIG. 5, the depth of the slot is in three stages, but the present invention is not limited to this number, and a plurality of stages may be adopted as appropriate depending on the purpose, conditions of use, etc. Further, in the same embodiment, cemented carbide was used as the wear-resistant material for the tip 7, but it goes without saying that any suitable wear-resistant material may be used.

[Brief explanation of drawings]

Figure M1 is a front view of a commonly used diamond cutting wheel, Figure 2 is a sectional view of part of the same as above, Figure 3 is a front view of a part of a known diamond cutting wheel with a wear-resistant material attached to the slot part, Fig. q is a sectional view of the same as above, and Fig. S is a front view of the diamond cutting grindstone according to the present invention. l/... Board, /2, 13, /Hiro... Slot, /! ;, /l, /7... Wear-resistant tip patent applicant Asahi Diamond Airi Co., Ltd. agent
Tanu Fukiyoshi

Claims (1)

[Claims] Slots are formed on the periphery of the substrate at required intervals, and a diamond grinding wheel body is attached to the divided circumferential portions formed between the slots, wherein the slots are formed in a plurality of stages to different depths, A diamond cutting grindstone characterized in that a wear-resistant tip corresponding to the depth of each slot is attached to the slot.