SU1696176A1 - Multiflute drill for machining tetrahedral slots - Google Patents

Abstract

The invention relates to metal cutting. The purpose of the invention is to increase productivity. The countersink contains a tail part and a working part, which has a guide 1 and a cutting part 2. The guide part 1 is placed in a faceted conductor 3, the number of faces of which is equal to the number of sides of the groove to be machined. The guide part 1 is tubular with parallel envelopes of the outer and inner surfaces and has the shape of a curvilinear equilateral triangle in cross section. The cutting part 2 is made in the form of unidirectional cutting teeth located at the end and side surfaces of the extension of the guide part 1. In cross section, the envelope surface of the cutting edges of the end teeth 5 has the shape of curvilinear triangles located at the vertices of the guide part 1. Two sides of a curvilinear triangle are outlined by arcs of one radius equal to the radius of the arc of the outer envelope, and the third side is outlined by an arc whose radius does not exceed the radius of the arc on the outer envelope of the surface and the guide part 1. The center of the arc describing the third side of a curved triangle is located on the continuation of the bisector of the opposite angle so that the height of the curved triangle is made equal to the wall thickness of the guide part, which is equal to the width of the groove not machined. 5 il. SO with

Description

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The invention relates to metal cutting and can be used for machining tetrahedral grooves.

The aim of the invention is to increase productivity.

FIG. 1 shows a countersink, general view; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a section BB in FIG. one; in fig. 4 shows a section B-B in FIG. one; in fig. 5 is a view of FIG. one.

The countersink contains a tail part and a working part, which has a guide 1 and a cutting part 2. The guide part 1 is placed in a faceted conductor 3, the number of faces of which is equal to the number of sides of the groove to be machined. The guide part 1 is tubular with parallel envelopes of the outer and inner surfaces and has the shape of a curvilinear equilateral triangle - frame 4 in cross section. The cutting part 2 of the countersink is made in the form of unidirectional cutting teeth located on the end and lateral surfaces of the extension of the guide part 2 In cross section, the envelope surface of the cutting edges of the end teeth 5 has the shape of curvilinear triangles 6 located at the vertices of the guide part 2. Two sides of the triangle 6 o arcs of one radius equal to the radius of the arc of the outer envelope of guide part 2, and a third side outlined by an arc whose radius does not exceed the radius of the arc of the outer envelope of guide part 2. The center of the arc describing the third side of a curvilinear triangle is located on the extension of the bisector of the opposite angle so that the height of the curved triangle is made equal to the wall thickness of the guide part, which is equal to the width of the groove to be machined. The number of curvilinear triangles 6 is equal to the number of faces of the guiding part 1, i.e. three

The cutting teeth 5 are designed to perform the main cutting work, and the final teeth 7 and 8, located on the lateral outer and inner surfaces of the curvilinear triangles 6, are designed to perform the auxiliary cutting work. The cutting teeth on the face and the teeth 7 and 8 on the side surfaces are located at an angle of 90 °. The tooth 5 at the end of the cutting part 2 countersinks have a full profile and are sharpened at a positive rake angle y and a posterior angle a. On the anterior side of the tooth, there is a chip cavity to accommodate the bulk of the metal to be removed. Side cutting edges have incomplete

profile without chip cavities. They perform auxiliary cutting work and help reduce friction forces on the auxiliary surface of the cutting blade.

Part 2. The volume of metal removed by them is insignificant.

The end 5 and lateral 7 and 8 teeth are unidirectional, and the cutting edges of the end and side teeth coincide.

0, the pitch of the teeth on the outer and inner surfaces of the countersink cutting element is the same, and the pitch depends on the width of the groove 9 in the workpiece 10. The height of the cutting elements is made greater than the depth of the groove 9 to be machined. the surface of the cutting part 2 is made of a transverse groove 11 for the tool to exit, for example, firmware. The guide part 1 is rigidly connected, for example, the shank 12 is welded. The shank 12 of the countersink is welded to the multifaceted guide part 1 by means of

5 multi-sided flange, the size and configuration of which correspond to the size and configuration of the guide part 1 countersink. The dimensions of the guide 1 and the cutting 2 countersinker's parts according to the diameter of the inscribed

0 in the outline of its circumference profile and circumference circumscribed around it are determined by the known geometric ratios of the dimensions of the tetrahedral groove.

5 Zenker works as follows. To prepare the quadratic groove, no preliminary preparation of the groove cavity is required. The machining of the groove is mainly carried out on machines with

0 vertical spindle, for example, vertical drilling. The countersink shank is inserted into the floating cartridge 13, and the guide piece 1 passes through the faceted jig 3 ..

5 When countersinking, the countersink axis does not coincide with the axis of symmetry of the faceted groove and the conductor sleeve. Due to the misalignment of the axes during processing, a special floating cartridge 13 must be used.

0 The design of such a floating cartridge can be based on the application of the principle of the so-called Oltigame coupling. When countersinking, torque from the machine spindle through the top

5 of the cartridge is transferred to the lower part thereof by means of an intermediate washer. During the countersinking process, the lower part of the cartridge together with the countersink moves in the direction transverse to the axis, due to the shape of the conductor sleeve and the cross section of the counterpart working section. Countersinking is performed by gradually incising the countersink on each pass to the depth of cut according to the chosen mode. The cutting teeth 5 at the tip of the countersink perform the main cutting work and they accumulate the bulk of the metal to be removed, the side teeth 7 and 8 perform auxiliary cleaning work, and the volume of the metal to be removed is small resulting from the cleaning of the side surfaces of the groove. Since when rounding the quadrilateral groove, small rounding of corners is formed at the place of the ribs, then to achieve the exact shape of the polyhedral groove with pointed edges after the countersink, a calibration mandrel is produced.

Claims (1)

An invention of a countersink for treating tetrahedral grooves, comprising a shank, a cutting part and a guide part, the cross section of which envelope surface has the shape of a curvilinear equilateral triangle, characterized in that, in order to increase productivity, the guide part is made tubular with parallel envelopes of the outer and inner surfaces, and the cutting part is made in the form of unidirectional cutting teeth arranged at equal pitch on the end and side surfaces of the extension of the guide part, while the envelope surface the cutting edges of the end teeth have the shape of curvilinear triangles located at the vertices of the guide part, the two sides of which are outlined with arcs of one radius equal to the radius of the arc envelope of the guide part, and the third side is outlined by an arc whose radius does not exceed the radius of the arc of the outer envelope of the guide part, and the arc center describing the third side of the curvilinear triangle is located on the extension of the bisector of the opposite angle so that the height of the curvilinear triangle is equal wall thickness of the guide. Aa one Fm.z FI.4 Widg 5