SU1247171A1 - Cutoff tool - Google Patents

Description

The invention relates to metal working.

The purpose of the invention is to increase tool life, increase reliability and expand the technological EYUZ cutter capabilities.

FIG. 1 shows the proposed cutter, a plan view; in FIG. 2 —A-A section 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 cross-section of the FIG. one; in fig. 6 - scheme of action of forces at the tip of the tool without reinforcement, chamfering; in fig. 7 the same, with reinforcing chamfer.

The cutter contains the main cutting edge 1, the leading angle 2 (f ″), the angle in plan 3 (f), the rear angle 4 (en), the front 5 and the rear surfaces of the blade 6, which form in the area of the cutting edge at the points of their crossed tip 7 8 cutter. At the tip 7 with the formed acute angle 9 (e), the reinforcing negative chamfer 10 uniformly decreasing with respect to the axis of symmetry of the cutter 10 with an inclination angle of 11 (I./) and negative rake angle 12 (Ul) - Chamfer 10 equal to half the width of the cutter in. The magnitude of the negative rake angle 12 of the chamfer 10 in the cross section, passing normally to the line 13 of the mating surface 14 of the chamfer with the front surface 5 of the tool, is equal to the value of the posterior angle 4 in the normal section area. Between the surface of the chamfer 14 and the rear surface 6, an angle of sharpening 15 (p) is formed.

5 5 o

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The chamfer B in the form of a bevel has a maximum surface area at the highest stress concentrations at the apex of the tool having an acute angle, which increases the brittle strength of the cutting wedge in the most dangerous sections. As the chamfer surface moves away from them, the effect of the radial component of the cutting force decreases.

The presence of a negative hardening chamfer 10 with a wedge 7 increases the angle of a sharpening 15 (P), which contributes to an increase in the brittle strength of the cutting wedge.

In addition, in the presence of a negative chamfer, the normal cutting force components, H ifiPn, acting on the front surface of the tool on the chamfer surface, under the action of PN / compressive stresses and non-tensile stresses, in its absence, which prevents chipping and cutting out at the entrance and exit of the tool from contact with the part during the cutting process.

The use of the proposed construction prevents the brittle fracture of the tool tips to the places of the highest stress concentrations and increases its reliability in operation.

In addition, hardening the tip of the cutter with an acute angle in the plan allows increasing the value of the rake angle to ensure favorable conditions of the cutting process when processing metals with different physicomechanical properties and expands its technological capabilities.

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Claims (1)

A CUTTING CUTTER with a main cutting edge, a rake angle, a 90 ° angle in the plan, a trailing angle, a front and a back surface of the blade, forming a cutting tip at the intersection of the cutting edge at the points of intersection thereof, with a negative reinforcing bevel, characterized in that, in order to increase durability, reliability and expand the technological capabilities of the cutting tool, a negative reinforcing bevel is located only at the apex with an acute angle in plan and is made in the form of a bevel uniformly decreasing from the apex to the axis of the sim etrii cutter, wherein the chamfer angle is associated with a rake angle of the chamfer, its amount and ratio of the width of the cutter tgX / = where λ} - chamfer angle of inclination; m is the normal distance from the tip of the cutter to the line of contact between the surface of the chamfer and the front surface of the cutter; y / _n is the rake angle of the chamfer in the normal secant plane passing _Λ through the tip of the cutter; § b - the width of the cutter. SU. „, 1247171 Fig. /