RU2519449C1 - Diamond cutoff wheel - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention can be used in manufacturing of diamond cutoff wheels for cutting of hard and brittle materials such as ruby, sapphire, ceramics. A wheel comprises a disk casing with grooves for the depth of (0.05-0.1) of the diamond wheel width being made on its side surfaces. The grooves profile is shaped according to a curve specified by an equation which defines a current curve angle read from the curve start on the wheel periphery, depending on the current curve radius, diamond wheel radius, curve end radius and diamond layer height. Afterwards the diamond layer is electrodeposited on the wheel casing.

EFFECT: increased durability of a diamond cutoff wheel by 2 times as compared to a known wheel.

3 dwg, 1 tbl

Description

The invention relates to the field of tool industry, in particular to diamond cutting wheels for cutting hard and brittle materials (e.g. ruby, sapphire, ceramics).

The prior art diamond cutting segment wheel containing a disk casing with radial working diamond-containing segments located on its periphery (GOST 16115-88, "Diamond cutting wheels of forms 1A1RSS / C1 and 1A1RSS / C2. Technical conditions").

A disadvantage of the known technical solution is the uneven wear of the points of the end cutting edges of the diamond wheel due to a change in cutting speed along the edge and leading to a decrease in the resistance of the diamond wheel.

The closest technical solution to the proposed invention is a diamond segmented cutting wheel with inter-segment cuts, made in the form of a housing with a thickened stepped rim, on the periphery of which a diamond-bearing layer is fixed (USSR Author's Certificate No. 1133077, B24D 5/12, 1985).

A disadvantage of the known technological solution is also the uneven wear of the points of the end cutting edges of the diamond wheel, due to a change in cutting speed along the edge and leading to a decrease in the resistance of the diamond wheel.

The technical task of the invention is to increase the resistance of the diamond wheel by aligning the projection of the cutting speed vector of the points of the end cutting edges to the normal to the end cutting edge, which leads to the alignment of wear of the points of the end cutting edges.

The problem is solved by the fact that in the diamond cutting wheel containing a disk case with grooves on the side surfaces, with a diamond layer attached to it, according to the invention, the grooves are made to a depth of a = (0.05 - 0.1) T, where T - the width of the diamond wheel, and the profile of the grooves is made according to the curve defined by the following equation:

$$\mu =\arcsin \left(\frac{R_{\mathrm{one}}}{R}\right)+\frac{\sqrt{R^2-R_{\mathrm{one}}{}^2}}{R_{\mathrm{one}}}-\arcsin \left(\frac{R_{\mathrm{one}}}{r}\right)-\frac{\sqrt{r^2-R_{\mathrm{one}}{}^2}}{R_{\mathrm{one}}}$$

Where:

µ is the current angle of the curve, measured from the beginning of the curve on the periphery of the circle;

r is the current radius of the curve;

R is the radius of the diamond wheel;

R ₁ = R - (1,1 ... 1,5) h is the radius of the end of the curve;

h is the height of the diamondiferous layer.

The invention is illustrated by drawings, where:

- figure 1 is a view in plan of a diamond cutting wheel;

- figure 2 is a section aa in figure 1;

- figure 3 - the design of the grooves and the components of the vector of the cutting speed of the points of the end cutting edge,

where respectively are depicted:

1 - disk enclosure;

2 - groove;

3 - diamondiferous layer;

4 - end cutting edge;

5 - point of the end cutting edge;

6 - cutting speed vector at the point of the end cutting edge;

7 - projection of the cutting speed vector at the point of the end cutting edge on the normal to the end cutting edge;

8 - normal to the end cutting edge;

9 is a projection of the cutting speed vector at the point of the end cutting edge onto the tangent line to the end cutting edge;

10 - tangent line to the end cutting edge.

The declared diamond cutting wheel contains a disk casing 1, on the side surfaces of which grooves 2 are made to a depth of a = (0.05 - 0.1) T, where T is the width of the diamond wheel. The profile of the grooves 2 is performed along the curve AB defined by the following equation:

$$\mu =\arcsin \left(\frac{R_{\mathrm{one}}}{R}\right)+\frac{\sqrt{R^2-R_{\mathrm{one}}{}^2}}{R_{\mathrm{one}}}-\arcsin \left(\frac{R_{\mathrm{one}}}{r}\right)-\frac{\sqrt{r^2-R_{\mathrm{one}}{}^2}}{R_{\mathrm{one}}}$$

Where:

µ is the current angle of curve AB, counted from the beginning of curve A at the periphery of the circle;

r is the current radius of the curve;

R is the radius of the diamond wheel;

R ₁ = R - (1,1 ... 1,5) h - radius of the end of the curve AB;

h is the height of the diamond layer 3.

Then, the diamondiferous layer 3 is plated onto the body 1 in a galvanic manner. The geometry of the end cutting edges 4 is determined by the curve AB.

At the production site of FSBEI HPE MSTU "STANKIN" the tests of the proposed design, namely a diamond cutting wheel with a radius of R = 125 mm, a thickness of T = 2.5 mm, containing 23 grooves, with a diamond layer height h = 7 mm intended for cutting granite and ceramic tiles.

The diamond cutting wheel was a disk casing 1, on the side surfaces of which grooves 2 were made to a depth of a = 0.25 mm. The profile of the grooves 2 was performed according to the curve AB defined by the following equation:

, $$\mu ={91.44}^{\circ }-\arcsin \left(\frac{114.5}{r}\right)-\frac{\sqrt{r^2-{114.5}^2}}{114.5}$$

,

Where:

µ is the current angle of point 5 of curve AB, counted from the beginning of curve A of AB at the periphery of the circle;

r is the current radius of point 5 of the curve AB,

moreover, the end B of curve AB lay on a circle with a radius R ₁ = 114.5 mm.

The vector of cutting speed 6 at any point 5 of the end cutting edge 4 was determined by two components - the projection 7 of the vector of cutting speed 6 on the normal 8 to the end cutting edge 4 and the projection 9 of the vector of cutting speed 6 on the tangent line 10 to the end cutting edge 4. During the cutting process the wear of points 5 of the end cutting edge 4 was determined mainly by the projection 7 of the cutting speed vector 6 on the normal 8 to the end cutting edge 4, because the second component of the cutting speed vector 6 is the projection 9 of the cutting speed vector 6 on the tangent line 10 to the end cutting edge 4 during the cutting process corresponded to the movement of the section of the cutting edge 4 at point 5 along itself along the tangent line 10, which did not lead to the removal of the allowance and wear of the cutting edge 4 at point 5.

Due to the indicated design of the grooves 2, the projection 7 of the cutting speed vector 6 on the normal 8 to the end cutting edge 4 at any of its point 5 was constant and amounted to 0.916 v, where v (m / min) is the cutting speed specified by the modes, therefore, the wear of the end faces cutting edge 4 was constant. The end cutting edge 4 did not contain a section or sections with increased wear compared to the rest of the sections. The presence of sections of the end cutting edge 4 with increased wear determines the low resistance of the known diamond cutting wheel, which was defined as the total cut area of the machined parts and amounted to 0.5-0.6 m ² .

The durability of the declared circle was determined by the wear of all sections of the end cutting edge 4 and amounted to 1.0-1.2 m ² , which exceeds the durability of the known circle by 2 times.

Thus, the claimed combination of essential features set forth in the claims, allows to increase the durability of the diamond cutting wheel by 2 times compared with the known circle.

Below is a table that confirms the materiality of the intervals claimed in the claims.

Table The radius of the end In the curve AB R ₁ Groove depth a Task to be solved R - 1,0 h 0.15 T The height of the groove 2 is R - R ₁ = h, i.e. is equal to the height h of the diamondiferous layer 3. The lower point of the end cutting edge 4 lies on the bottom of the groove 2. When cutting, the coolant moves to the periphery of the circle along the groove 2, its speed at the bottom of the groove 2 is close to zero, therefore, the lower parts of the end cutting edge 4 are not exposed exposure to coolant to the necessary extent, which leads to insufficient cooling and increased wear, which corresponds to marriage. Increasing the depth of the groove leads to a decrease in the thickness of the diamond wheel in the groove area, which leads to a decrease in its rigidity, which can lead to chipping of the housing elements under the action of cutting forces, which corresponds to marriage. R - 1.1 h 0.1 T Providing coolant exposure throughout the entire end cutting edge 4. The value of the groove depth ensures the unimpeded removal together with the coolant of the spent grains of abrasive material and material particles of the workpiece, and also provides cutting conditions at the end cutting edge 4. R - 1.2 h 0.085 T Providing coolant throughout the entire cutting edge 4.

The value of the depth of the groove provides unhindered removal together with the coolant of the spent grains of abrasive material and material particles of the workpiece, and also provides cutting conditions at the end cutting edge 4. R - 1.4 h 0.065 T Providing coolant exposure throughout the entire end cutting edge 4. The value of the groove depth ensures the unimpeded removal together with the coolant of the spent grains of abrasive material and material particles of the workpiece, and also provides cutting conditions at the end cutting edge 4. R - 1,5 h 0.05 T Providing coolant exposure throughout the entire end cutting edge 4. The value of the groove depth ensures the unimpeded removal together with the coolant of the spent grains of abrasive material and material particles of the workpiece, and also provides cutting conditions at the end cutting edge 4. R - 1,6 h 0.04 T The height of the groove 2 is R - R ₁ = 1.6 h, i.e. greater than the height h of the diamond layer 3. Such an increase in the height of the groove 2 reduces the rigidity of the cutting segments of the diamond wheel, which causes a risk of breaking off the segment, which corresponds to marriage. The depth of the groove is too small for unimpeded removal, together with the coolant, of the spent grains of abrasive material and particles of material of the workpiece, which can lead to a deterioration of the cutting conditions at the end cutting edge 4.

The analysis of the claimed technical solution for compliance with the conditions of patentability showed that the characteristics indicated in the independent claim are interrelated with each other with the formation of a stable set of necessary attributes unknown at the priority date from the prior art sufficient to obtain the required synergistic (over-total) technical result.

The properties regulated in the claimed invention by individual features are well known in the art and require no further explanation.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed technical solution:

- the object embodying the claimed technical solution, when implemented, is intended for use in the field of tool industry, for the manufacture of diamond cutting wheels for cutting hard and brittle materials;

- for the claimed object in the form described in the independent claim, the possibility of its implementation using the means and methods known from the prior art on the priority date on the priority date has been confirmed;

- the object embodying the claimed technical solution, when implemented, is able to ensure the achievement of the technical result perceived by the applicant.

Therefore, the claimed subject matter meets the requirements and patentability conditions of “novelty”, “inventive step” and “industrial applicability” under applicable law.

Claims (1)

A diamond cutting wheel containing a disk case with grooves on the side surfaces and with a diamond layer fixed on it, characterized in that the grooves are made to a depth of a = (0.05-0.1) T, where T is the width of the diamond wheel and the profile the grooves are made according to the curve given by the following equation:

,Where
µ is the current angle of the curve, measured from the beginning of the curve on the periphery of the circle;
r is the current radius of the curve;
R is the radius of the diamond wheel;
R ₁ = R- (1,1 ... 1,5) h is the radius of the end of the curve;
h is the height of the diamondiferous layer.

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