JPH07112371A - Super abrasive grain grinding wheel and grinding method - Google Patents

Abstract

PURPOSE:To provide super abrasive grain grinding wheel and a grinding method wherein grinding is practicable even at a limited space and a grinding work is practicable in succession for a long time. CONSTITUTION:In a grinding wheel having a super abrasive grain layer 5 and a base layer 6, the base layer is formed in a manner to protrude from the super abrasive grain layer toward the work (a chip 10) side. In grinding, the base layer 6 is first collided with the work and the surface of the base layer is deleted approximately by an amount of a cut work. Grinding of the work is effected by the super abrasive grain layer 5 protruded through deletion. The shearing force of the base layer is set to 0.4-1.2kg/mm<2> so that deletion of the base layer 6 is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to civil engineering such as a tip saw,
TECHNICAL FIELD The present invention relates to a superabrasive grindstone used for producing a tool for processing metal and a grinding method using the grindstone.

[0002]

2. Description of the Related Art For example, as shown in FIGS. 2A and 2B, a tip saw used for cutting metal has a plurality of grooves 9 formed on the outer peripheral end surface of a body 8 made of a steel disk, each of which is made of cemented carbide. , A chip 10 made of sintered diamond or CBN sintered body is brazed.

Each of the brazed chips 10 is uniformly and entirely ground by a superabrasive grindstone 4 using superabrasive grains such as diamond grains.

This grinding is to make the grinding uniform, and at the same time, to give a required sharp tip shape, and therefore, it must be carried out from both sides, tip surface and scooping surface of the chip 10.

As shown in FIGS. 3A and 3B, in the side surface grinding and the tip surface grinding, the superabrasive grain layer 5 of the cup-shaped superabrasive grain grindstone 4 is brought into contact with the surface of the tip 10 to be ground and slid in rotation. Meanwhile, the whetstone is moved back and forth in the direction of the arrow. When moving the grindstone as well as moving it forward and backward, the grindstone always comes into contact with only one side of the body 8 which is the work or one surface of the tip 10 that is most protruded from the outer peripheral end surface, so that there is no spatial restriction and the movement width can be set freely. it can.

[0006]

However, in the grinding of the scooping surface, as shown in FIG. 3C, the grindstone must penetrate the groove 9 of the body 8 and slide on the scooping surface of the chip 10. The moving width of the advance / retreat is absolutely limited by the size of the groove, and the feed is also affected by it.

Moreover, the size of the groove 9 is, for example, as shown below, in a cemented carbide tip saw having a body diameter of 305 mm and 100 chips, the width from the inner peripheral edge of the tip 10 to the groove bottom of the body 8 is There is only a few mm, and conversely the superabrasive layer 5 of the grindstone 4
It is said that it is preferable to go over the scooping surface of the chip 10 at the most advanced end and to leave the chip 10, that is, to remove it completely, so the width of the superabrasive grain layer 5 must be reduced to a few mm or less. Body diameter Chip width Body thickness Shaft hole diameter Number of chips 305mm × 2.0mm × 1.6mm × 32mm × 100

Further, as described above, since the body thickness is as thin as 1.6 mm, there is chattering near the ground portion, but chatter occurs due to sliding. Therefore, the width of the superabrasive grain layer 5 is also from this surface. It is necessary to make it smaller and weaken the grinding resistance.

As described above, because of the large spatial and grinding restrictions, the grindstone has a small dish-shaped superabrasive grain layer 5 and a small bonding area as shown in FIG. 3C.

However, as a grinding condition, in order to shorten the grinding time, one-pass processing by deep cutting or grinding by a quick stroke is desired.
The wear of the superabrasive layer is so severe that it cannot meet this demand.

FIG. 4 is a proposal for improving this, in which there is a superabrasive grain layer 5 provided on the outer periphery through a base layer 6, but a step 7 with the base layer has a step 7 of the superabrasive grain layer 5. It disappears due to the reduction due to grinding, and heat and chatter are generated due to friction with the base layer. Therefore, it is necessary to repeatedly grind the base layer during grinding to maintain a step, and it is not possible to improve grinding efficiency.

[0012]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems and to provide a new grindstone which goes beyond the conventional concept of a grinding grindstone and a grinding method using the grindstone. .

That is, in a grindstone having a superabrasive grain layer and a base layer, for example, a diamond wheel, a base layer having a constant value lower than the shearing force of a general base layer is provided on the outermost peripheral side, and the superabrasive grain layer is provided on the inner peripheral side. Is provided.

With this configuration, the base layer first contacts the work during grinding, and the surface of the base layer is scraped off by the low shearing force by an amount substantially equal to the cutting depth of the work, and the grinding is performed by the superabrasive grain layer protruding by the scraping. Can be advanced.

Therefore, no work for removing the surface of the base layer is required at the beginning of the grinding or during the grinding, the thickness of the superabrasive grain layer can be made sufficiently large, and the necessary minimum level difference can always be maintained. The details will be described below with reference to the illustrated embodiment.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a longitudinal sectional side view of a portion of a dish type grindstone of the present invention, in which 1 is an aluminum alloy body having a shaft hole 2 and 6 is a base made of a porous phenol resin adhered to an outer peripheral end surface 3 of the body. Layers 5 are superabrasive layers in which diamond abrasive grains adhered to the inner surface of the base layer are hardened with a phenol resin. The abrasive grain was a metal-coated synthetic diamond with a grain size of 200, and the concentration was 100. The grindstone diameter is 130 mm,
The thickness X of the superabrasive grain layer 5 on the outer peripheral edge side is 1 mm, the thickness X'of the base layer 6 is 1.5 mm, the width W of the superabrasive grain layer 5 is 1.5 mm, the length L is 15 mm, and the composition of the base layer 6 is The shearing force is shown in Table 1. Although the thickness X'of the base layer 6 is increased as it goes to the inner circumference, the strength is increased, but it may be the same.

[0017]

[Table 1]

The composition of the base layer 6 having the structure shown in FIG. Grinding stones of 1 to 12 types were produced, and the scooping surface of the cemented carbide tip saw having the configuration shown in FIG. 2 was ground under the following conditions. It was possible to carry out grinding continuously. Grinding wheel peripheral speed Vs = 26m / S, work sliding Vw = 120mm / min Depth of cut a = 0.1mm / pass Grinding liquid JIS W2 type

FIG. 1B shows that the base layer 6 has the chip 10 at the beginning of grinding.
A chain line Y that touches the (workpiece) and hits the cut amount of the chip 10
Of the superabrasive grain layer 5 which is cut off and thereby projected
This is a schematic illustration of the progress of grinding by. Further, in Table 1, the numerical value in the column of grinding resistance shows the grinding resistance of only the base layer, and sliding measurement was carried out with a width of 1 mm of the base layer projected.

As shown in Table 1, the shearing force of the base layer becomes smaller as the volume of the porous phenol resin increases and the amount of graphite added becomes smaller, and the contact portion with the chip is easily scraped off, resulting in the cutting of the work. The removal of the base layer, which roughly corresponds to the amount, is smooth. However, on the other hand, since the reinforcing strength of the superabrasive grain layer decreases, 0.4 to 1.2 kg / mm ² preferably 0.7 to 1.
2kg / mm ² should be selected.

It is preferable that both the superabrasive grain layer and the base layer are made of a phenol resin as in the above-mentioned embodiment in view of the adhesive strength in manufacturing, but other resins or other materials may be used in some cases. is there. In each case, since it is difficult to maintain uniform shaving through continuous pores in the porous formation in the base layer, minute independent pores of several microns to 100 microns are generated, and the density is set to about 0.2 g / cm ³ . It is preferable.

[0022]

As described above, in the grindstone of the present invention, the base layer is provided so as to project from the superabrasive grain layer toward the work side, and the length can be made longer than the width of the superabrasive grain layer. Moreover, since the base layer has the required reinforcing strength, low shearing force, and good machinability, it hits the work during grinding and is scraped off by approximately the cut amount of the work. Since the grinding progresses by the layer, it is not necessary to cut off the base layer with a cutting tool or a stick of a general grindstone to project the superabrasive grindstone during grinding as in the conventional case, and the life of the grindstone is extended.

Therefore, it is possible to carry out continuous grinding work in a narrow place, save man-hours and proceed with automatic grinding.

[Brief description of drawings]

1A and 1B show an embodiment of the present invention, in which A is a partially longitudinal side view of a grindstone, and B is a schematic view for explaining a grinding state.

2A and 2B respectively show a front view and a side view of a part of a conventional tip saw ground by a grindstone of the present invention.

3A, 3B, 3C and 3D are schematic views illustrating a method of grinding a side surface, a tip end surface and a scooping surface of a tip in a tip saw, respectively.

FIG. 4 is a partial vertical sectional side view of a grindstone showing a conventional proposal example.

[Explanation of symbols]

 1 Aluminum alloy body 2 Body shaft hole 3 Body outer peripheral edge surface 4 Superabrasive grindstone 5 Superabrasive grain layer 6 Base layer 7 Step between base layer and superabrasive grain layer X Superabrasive grain layer thickness X'of base layer Thickness W Width of super-abrasive grain layer L Length of super-abrasive grain layer Y Cut-off part of base layer 8 Body of tip saw 9 Groove provided on outer peripheral edge of body 10 Tip brazed to the tip of groove

Claims (2)

[Claims] 1. A grindstone comprising a superabrasive grain layer and a base layer holding the superabrasive grain layer, wherein the base layer is provided so as to project from the superabrasive grain layer toward the work side, and the shearing force of the base layer is 0.4.
Super abrasive grain whetstone characterized by ~ 1.2kg / mm ² . 2. In grinding, the base layer of the grindstone first hits the work, and the surface of the base layer is removed by an amount substantially equal to the cut amount of the work, and the work is ground by the superabrasive grain layer protruding by the removal. A grinding method using a superabrasive grindstone.