RU2399463C2 - Engraving cutter - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to the field of machine-tool construction. Engraving cutter comprises cylindrical tail and working cutting part with front and main back planes, blunting surface with end cutting edge and auxiliary back conical surface with straight generatrix line. Generatrix line of auxiliary back conical surface is arranged in the form of circumference part. Blunting surface, front and main back surfaces are arranged in the form of part of cylinder surfaces, at the same time axes of symmetry in front and main back surfaces are perpendicular to axis of tail symmetry, and axis of blunting surface symmetry is parallel to end cutting edge.

EFFECT: invention makes it possible to reduce volume of polished material, to increase durability, to eliminate necessity of periodical straightening of abrasive tool.

2 cl, 5 dwg

Description

The invention relates to the machine tool industry, and in particular to types and forms of manufacturing cutting tools of milling machines, and is intended for engraving grooves and drilling conical holes, for example, for milling and drilling foil and non-foiled material of printed circuit boards, as well as for engraving inscriptions on metal products and dielectrics.

Known engraving cutter containing a cylindrical shank and a working cutting part with front and main rear planes, a blunt surface with an end cutting edge and an auxiliary rear conical surface with a straight generatrix (prototype).

The disadvantages of the prototype include low strength and stiffness of the cutter, low processability, manufacturing productivity and a small number of regrinds.

1. So, if the generatrix of the rear auxiliary conical surface of the cutter is a straight line, then at small cone angles the length of the side cutting edge is so large that the part of the cylindrical shank that is used to fasten the cutter in the collet of the machine spindle is cut off. With a standard length of the engraving cutter with a diameter of 3 mm (3.175 mm) 36 mm, the length of the cylindrical part of the cutter intended for fastening in the collet is 22.5 mm. 13.5 mm remain on the conical part. The minimum cone angle with a diameter at the end of 0.2-0.4 mm is 11-12 °. Therefore, engraving cutters of this design are produced with a minimum angle of 15 °.

2. When grinding an engraving cutter with a small angle of sharpening, more than half the mass of the workpiece is removed, which increases the processing time and wear of the abrasive tool.

3. With a large length of the generatrix of the cone, the resource decreases when re-regrinding the cutter.

4. At small angles of the cone of the cutter, the rigidity and strength of the tool are reduced.

In order to eliminate these drawbacks, the engraving cutter is characterized in that the generatrix line of the auxiliary rear conical surface is made as a part of a circle, the blunt surface, the front and main rear surfaces are made as part of the surfaces of the cylinders, while the axis of symmetry of the front and main rear surfaces are perpendicular to the axis of symmetry the shank, and the axis of symmetry of the blunting surface is parallel to the end cutting edge, while it is possible to perform an auxiliary rear surface of many hexagon that approximates a conical surface.

The essence of the proposal is illustrated by drawings.

Figure 1 shows an engraving cutter of known design (prototype). He has a front cutting and main back surfaces - flat. Auxiliary rear surface is conical. The blunting surface is also flat (not shown in the drawing).

Figure 2 shows the claimed design of the engraving cutter with the designations of the surfaces. Unlike the prototype, all forming surfaces are cylindrical. The advantages of this form - constructive, technological and operational - are given in the description of the application.

Figure 3 shows the inventive cutter, oriented so that the axis of symmetry of the front cutting cylindrical surface is perpendicular to the plane of the drawing and, therefore, perpendicular to the axis of the shank, which is in the plane of the drawing.

Figure 4 shows the cutter in a position where the axis of symmetry of the main rear cylindrical surface extends perpendicular to the plane of the drawing, i.e. also perpendicular to the axis of the shank. The axis of symmetry of the auxiliary rear cylindrical surfaces, as well as the main rear surface, are also perpendicular to the axis of the shank.

Figure 5 shows the cutter from the front cutting surface. The drawing shows that the end cutting edge is beveled, i.e. not perpendicular to the axis of the shank.

The engraving cutter has a smooth cylindrical shank 1, a cylindrical front surface 2, a main rear auxiliary cylindrical surface 3, a rear auxiliary surface 4 in the form of a radial smooth conical surface and a cylindrical blunt plane 5.

When the front surface intersects with the main rear surface, a side cutting edge 6 is formed, and with the blunting plane, an end cutting edge 7 is formed.

The angle between the planes forming the cutting edges is selected depending on the material of the cutter, cutting conditions and the material being processed. This information is contained in the recommendations of tool manufacturers and technology manuals.

In order to improve the manufacturability of the engraving cutter manufacturing process, the conical surface is made in the form of an approximated polyhedral surface 8. The number of faces is chosen so that the approximated polyhedral surface differs little from the conical. For example, for a cutter with a tail diameter of 3 mm, 12-18 faces (360 °) are enough.

The advantage of the multi-faceted shape of the auxiliary back surface is that when grinding each face, the abrasive wheel works “on the way out” and therefore wears evenly, automatically retaining its cylindrical shape. Due to this, the circle does not need periodic editing throughout the entire life cycle up to complete wear.

To increase the resistance of the cutter, it is mainly made of fine-grained hard alloys, for example, VK6-OM grade. As an abrasive tool, discs with a diamond-containing working part are used.

The inventive step is confirmed by the fact that (according to the claims) the front and main rear surfaces, as well as the blunt surface, are made cylindrical with a radius of curvature equal to the radius of the abrasive tool (abrasive wheel) sharpening the cutter, and the symmetry axis of the cylindrical front and main rear of surfaces are perpendicular to the axis of the shank, the axis of symmetry of the blunting surface is parallel to the end cutting edge, and the line forming the auxiliary rear conical surface The tee has the form of a segment of a circle whose radius is equal to the radius of the abrasive tool, and the positive (technical) effect is as follows:

- the volume of polished material is reduced;

- increases the vitality (resource) of the abrasive tool;

- eliminates the need for periodic editing of the abrasive tool;

- the length of the working part of the cutter is reduced and, as a result, the number of potential regrinds increases;

- increases the rigidity of the cutter and resistance to chipping during the milling process.

Information sources

1. Engraving cutter type HGS-3. Catalog "Equipment of the company ROLAND". 1991, p. 1 (Internet: www.Roland.ru) / prototype /.

Claims (2)

1. An engraving cutter containing a cylindrical shank and a working cutting part with front and main rear planes, a blunting surface with an end cutting edge and an auxiliary rear conical surface with a straight generatrix, characterized in that the generatrix line of the auxiliary rear conical surface is made as a part of a circle , the blunt surface, the front and main rear surfaces are made as part of the surfaces of the cylinders, while the axis of symmetry of the front and main rear surfaces Tey are perpendicular to the axis of symmetry of the shank and an axis of symmetry parallel to the end surface of the blunting of the cutting edge. 2. Engraving cutter according to claim 1, characterized in that the auxiliary rear surface is multifaceted, approximating a conical surface.

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