RU2262420C1 - Cutter to number program controlled machine - Google Patents

Abstract

FIELD: metal working in number program controlled machines.

SUBSTANCE: cutter includes active portion and stem. Cutter apex is arranged in its axis belonging to front surface. Main and trailing back faces are equally inclined relative to cutter axis and they cross front surface by positive back angles relative to main and trailing cutting edges having their own angles in plan view. Trailing back surfaces form second pair of surfaces inclined by the same angles relative to cutter axis. Inclination angles of main and trailing back surfaces relative to cutter axis is determined by value of back angle of main cutting edge. Trailing back surfaces are inclined by less angles relative to cutter axis. Active portion of cutter has at least with two chamfers equally inclined relative to cutter axis.

EFFECT: enhanced strength of cutter, improved stability of manufacturing process.

5 cl, 19 dwg

Description

The proposal relates to metal processing on a CNC machine and is intended, in particular, for engraving in the manufacturing process of drawings on metallographic forms used in the creation of printed products with a high degree of protection against counterfeiting.

Known cutter according to GOST 13288-76 of the USSR, having a shank and a working part, the tip of the cutter is located on its axis belonging to the front surface. The main and auxiliary rear surfaces are defined by the angles in terms of the main and auxiliary cutting edges, as well as by the rear corners of these edges in planes perpendicular to them. Moreover, the aforementioned rear surfaces forming the tip of the cutter are sharpened at different positions of its axis, which leads to unacceptable errors in the location of the tip of the cutter relative to this axis.

Also known is the incisor listed in the book of V.P. Shatin and Yu.V. Shatin. "Handbook of the designer-toolmaker", Moscow, "Mechanical Engineering", 1975, pp. 8 and 9. The working part of this cutter is characterized in that its apex is reinforced with a chamfer made on the main rear surface with the formation of a transition cutting edge adjacent to the main cutting edge. In this case, the tip of the cutter is made with an offset from the axis of the cutter, which is unacceptable with multi-pass planing with the rotation of the cutter around its axis.

The closest proposal for a technical substance (prototype) is a tool for machining according to the patent of the Russian Federation No. 2179094, having a working part and a shank. On the axis of the incisor belonging to the front surface is its top, which is formed with the help of all its rear surfaces, including additional ones.

The rear surfaces are made at the same angle to the axis of the cutter, each in its own plane, which passes through the axis of the cutter and is oriented relative to the front surface. In this case, the main and auxiliary rear surfaces intersect the front surface at positive rear angles relative to the main and auxiliary cutting edges, which are located at their own angles in the plan.

The cross section of the working part of the cutter has the shape of a versatile polygon, in particular a pentagon, in which the ratio of height to width is less than 0.5. This, as well as the value of the angle in terms of the main cutting edge, determines structurally the angle of inclination to the axis of the cutter of its rear surfaces.

The design feature of the cutter also consists in the fact that its working part is formed without taking into account the values of the rear angles of its cutting edges, which are not possible to take into account when manufacturing the cutter. However, the obtained value, in particular, of the trailing angle of the main cutting edge, is at least twice as large as the highest recommended for such cutting conditions.

At the same time, the angle of the cutting wedge in the plane passing through the top of the cutter is significantly reduced. These features of the dimensional parameters of the cutter, determined by its design, lead to a decrease in the resistance of the cutter, reduce the strength of its tip and thereby increase the likelihood of breakage of the cutter.

The task solved by the proposal is to increase the resistance of the cutter and the reliability of the process.

To do this, in the cutter for machining with a working part and a shank, in which the apex is located on its axis belonging to the front surface, the main and auxiliary rear surfaces are made with equal inclination to the axis of the tool and intersect the front surface at positive rear angles relative to the main and auxiliary cutting edges located at the same time at their own angles in the plan, and additional rear surfaces make up the second pair of surfaces made with equal inclination to the axis of the cutter, according to The main and auxiliary rear surfaces are made at an angle to the axis of the cutter, which is determined by the value of the rear angle of the main cutting edge, and additional rear surfaces are made at a smaller angle to the axis of the tool, and its working part is provided with at least two chamfers made with equal tilt to the axis of the cutter.

Chamfers can be made between additional rear surfaces in the form of faces opposite the front surface, while the main and auxiliary rear surfaces form the tip of the cutter, near which intersecting pairs of surfaces of the working part of the cutter form a convex contour.

In another embodiment, the chamfer cutter is made on additional rear surfaces, one of which intersects the main and the other auxiliary rear surfaces; chamfers can form the top of the cutter together with the main and auxiliary rear surfaces.

In another embodiment, the chamfers intersecting the main and auxiliary rear surfaces also intersect the front surface and form the tip of the cutter and transition cutting edges, one of which is adjacent to the main cutting edge, and the other to the auxiliary.

Figure 1, 2, 3 presents the proposed cutter for planing a V-groove, side views, top, front;

In Fig.4, 5 - section AOA and BOB in Fig.3;

In Fig.6, 7 - section B ₁ O ₁ B ₂ and GG in figure 2;

In Fig.8 - place "M" in Fig.1;

In Fig.9 is a section DV- ₂ in Fig.2;

In Fig.10, 11, 12 - section EE, KK and LL in Fig.8;

On Fig - contour processed by the cutter grooves;

On Fig, 15 presents the proposed cutter for planing a V-groove, side and front views, version 2;

In Fig.16 - section P ₁ SP ₂ in Fig.15;

On Fig, 18, 19 presents the proposed cutter for roughing planing, side views, top and front.

The cutter (1, 2, 3) contains a shank 1 and a working part 2 with a vertex 3 on the axis 4, which belongs to the front surface 5. The main 6 and auxiliary 7 rear surfaces (figure 4) are made to the axis of the cutter at an angle δ, which is determined by the value of the trailing angle of the main cutting edge α:

δ = arctan (ctgα cosφ sinψ),

Where

The above dependences are obtained using figure 2, 4, 6, 9.

The value of the rear angle α ₁ (Fig. 7) depends on α and φ-φ ₁ , and for φ = φ ₁ α ₁ = α.

Additional rear surfaces 8 and 9 are made at an angle δ ₁ to the axis of the cutter (figure 5), where δ ₁ <δ.

The working part 2 of the cutter is equipped with chamfers 12 and 13 (Fig. 3), which are made between surfaces 8 and 9 with equal inclination to the axis of the cutter in the form of faces opposite the front surface 5, while the values of angle θ and size m are provided (Fig. 1 )

Pairs of surfaces 8-9 and 12-13 are located so that they intersect the axis 4 of the cutter above its peak at points 17 and 18 (Fig. 8).

The values of the angles α and α ₁ provide a sufficiently large angle of sharpening β ₀ in the axial plane passing through the top of the cutter 3 (Fig. 8), near which pairs of opposite faces form a convex contour from segments 14, 15 and 16.

The cross section of the working part has the shape of a versatile heptagon, in which, near the shank, the ratio of height to width is less than 0.5 (Fig. 9), and as it approaches the tip of the cutter, this ratio increases, i.e.

(фиг.9, 12, 11, 10).

(Fig. 9, 12, 11, 10).

Near the tip of the cutter, the number of sides forming a cross section of the working part decreases from seven to five, and then to three (Figs. 12, 11, 10).

10, 11, 12, taken together, illustrate the steps of sequentially cutting a cutter into a workpiece; it is shown that this cutter can be used to process a groove whose radius of curvature along its inner contour

r _min ≥0.25 in ₀ ,

where at ₀ is the value of the width of the machined groove (Fig).

With this cutter, the groove of the V-shaped profile is processed in the form of the number "8" on the CNC machine, which provides movement along the coordinates X, Y, Z, C. Before processing, the cutter is fixed on the support of the machine and orientated by turning it along coordinate C, as shown in Fig, where a thin line shows the contour of the cross section of the working part of the cutter. By movements along the coordinates X, Y, Z, the cutter is moved to point C ₁ until the moment when its top touches the workpiece.

A groove is machined with simultaneous rotation of the cutter around its axis while maintaining an angle of 90 ° between the front surface 5 and tangent 40 to the trajectory, informing the cutter of the following movements:

- rotation around the axis O ₅ clockwise around a circle of radius R ₁ to point C ₂ with simultaneous movement along the Z coordinate to ensure a given groove depth;

- rotation around the axis O ₆ counterclockwise 360 ° around a circle of radius R ₂ with access to the point C ₂ ,

- rotation around the axis O ₅ clockwise 360 ° around a circle of radius R ₁ with access to point C ₂ ;

- moving along the Z coordinate from the workpiece and retracting the cutter to its original position.

In contrast to the first cutter described in the second embodiment (Figs. 14, 15), the chamfers 21 and 22 are made on additional rear surfaces 23 and 24, while the chamfer 21 intersects the main rear surface 25, and the chamfer 22 intersects the auxiliary rear surface 26.

The angle δ ₂ (Fig. 16) defines the inclination of the chamfers to the axis 28 of the cutter. The orientation relative to the front surface 20 of the chamfers and the surfaces on which they are made can be the same (angles ψ ₅ and ψ ₆ in Fig. 15). Chamfers 21 and 22 intersect the axis 28 of the incisor at point 27 and, together with the front surface 29 and surfaces 25 and 26, form the tip of the incisor. This cutter can be used to groove (Fig. 13) a V-shaped profile similar to the cutter proposed first.

In contrast to the first described in another embodiment of the cutter (Fig.17, 18, 19), the chamfers 31 and 32 are made on additional rear surfaces 33 and 34 so that they intersect the main 35, auxiliary 36 and front 37 of the surface of the working part 30. C Using these chamfers, a peak 38 and transition cutting edges 39 and 40 are formed, respectively, with the main 41 and auxiliary 42 cutting edges of the cutter.

This cutter can be used for pre-processing the grooves (Fig.13) of the V-shaped profile similarly to the cutter proposed first.

Thus, due to the fact that the vertex-forming main and auxiliary rear surfaces, in contrast to the prototype, are designed to provide a predetermined value of the trailing angle of the main cutting edge, the cutting wedge is increased both in the planes normal to the cutting edges and in the plane passing through the top of the cutter. However, in order to make it possible to process curved grooves with extremely small radii of curvature, a convex contour was created near the tip of the cutter using all the side surfaces of the working part of the cutter. The location of these surfaces is such that with approaching the tip of the cutter, the ratio of height to width in the cross section of the working part increases.

Compared with the prototype, the tip of the cutter is hardened, the heat removal from it is improved, the resistance of the cutter and the reliability of the process are increased.

High precision manufacturing of the cutter is ensured by processing intersecting pairs of surfaces with a constant position of its axis.

Claims (5)

1. The cutter for machining with a working part and a shank, the tip of the cutter is located on its axis belonging to the front surface, the main and auxiliary rear surfaces are made with equal inclination to the axis of the tool and intersect the front surface at positive rear angles relative to the main and auxiliary cutting edges, which at the same time are located at their own angles in the plan, and additional rear surfaces make up the second pair of surfaces made with an equal inclination to the axis of the cutter, characterized in that the main and auxiliary rear surfaces are made at an angle to the axis of the cutter, which is determined by the value of the rear angle of the main cutting edge, and additional rear surfaces are made at a smaller angle to the axis of the tool, and its working part is provided with at least two chamfers made with equal inclination to the axis cutter. 2. The cutter according to claim 1, characterized in that the said chamfers are made between additional rear surfaces in the form of faces opposite the front surface, while the main and auxiliary rear surfaces form the tip of the cutter, near which the intersecting pairs of surfaces of the working part form a convex contour. 3. The cutter according to claim 1, characterized in that the said bevels are made on additional rear surfaces, one of which intersects the main and the other auxiliary rear surfaces. 4. The cutter according to claim 1 or 3, characterized in that the said bevels together with the main and auxiliary rear surfaces form the tip of the cutter. 5. The cutter according to claim 1 or 3, characterized in that the said chamfers intersect the front surface and form the tip of the cutter and transition cutting edges, one of which is adjacent to the main cutting edge, and the other to the auxiliary.

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