JPH06210510A - Positive throwaway tip - Google Patents

Abstract

(57) [Summary] [Structure] A main cutting edge 44 is formed on the ridge line between the rake face 28 and the flank 30 on which the breaker is formed, and the flank 30 is formed in a multi-step surface shape by a plurality of continuous constituent planes. The first cutting edge 4 which inclines the main cutting edge 44 toward the lower surface at a predetermined angle.
4a and a second cutting edge 44b continuous with the first cutting edge 44a
It consists of and. [Effect] It is possible to improve the sharpness while ensuring the necessary cutting edge strength for each part of the main cutting edge, and to improve the chip discharge performance and reduce the cutting resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive indexable insert (hereinafter referred to as "chip") used for a throw-away type cutting tool (hereinafter referred to as "cutting tool") such as an end mill.

[0002]

2. Description of the Related Art FIGS. 17 to 19 show a conventional cutting tool equipped with a tip, in which reference numeral 2 indicates a tool body. This tool body 2
Is a substantially cylindrical shape whose base end is held rotatably around the axis X by a drive source such as an end mill, and a tip part of which is largely removed toward the outer circumference. A pocket 4 and a chip mounting surface 6 that faces the rotation direction of the tool body 2 are formed. A chip mounting seat 8 is formed on the chip mounting surface 6, and a chip 10 is removably mounted on the chip mounting seat 8.

As shown in FIGS. 20 to 22, the chip 10 has a substantially diamond-shaped appearance, and has a lower surface (seat surface) 12 which is a flat surface and an upper surface 14 thereof. Is taken as a scoop. A convex curved main cutting edge 18 is formed on the ridge portion between the upper surface 14 and the side surface 16. In such a conventional tip, since the upper surface 14 has a convex curved surface to ensure a large cutting edge angle, it has excellent cutting edge strength, and is mainly suitable for heavy cutting such as when the work material is steel.

However, when a soft and low melting point material such as aluminum is to be cut by using the above-mentioned tip, the requirement for the cutting edge strength as described above is not so large, and rather, the cutting edge angle is large, which is preferable. However, there are problems such as not being able to obtain a good sharpness, and that aluminum or the like is likely to be continuous chips and the chip discharging property is deteriorated to easily cause welding. For such problems, it is possible to increase the axial rake angle and improve the sharpness by inclining the tip mounting seat of the tool body. Since the thickness gradually decreases toward the base end side of the tool body, there is a problem that the strength of the tool body must be sacrificed.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to obtain good sharpness and chip discharging property even for a soft material such as aluminum.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a chip which is formed into a polygonal flat plate shape and has a lower surface which is a flat surface and which is removably attached by abutting the lower surface against a chip seat formed in a tool body. In, the main cutting edge is formed on the ridge portion between the upper surface which is a rake surface and the side surface which is a flank while the breaker is formed, and the flank surface is a multi-step surface formed by a plurality of continuous constituent planes. Shaped, the main cutting edge is composed of a first cutting edge that is inclined toward the lower surface at a predetermined angle, and at least one or more linear cutting edges that are continuous with the first cutting edge. It is characterized by The main cutting edge may be formed in a straight line when viewed in the normal direction of the lower surface, and when viewed in the normal direction of the lower surface, the first cutting edge is a cutting line that is continuous with the first cutting edge. It may be formed so as to be inclined toward the inside of the chip with respect to the blade. At least one of the cutting edges forming the main cutting edge may be formed parallel to the lower surface. Further, a linear sub-cutting edge extending in a direction substantially orthogonal to the flank may be formed at the tip of the first cutting edge of the main cutting edge. It may be formed parallel to the lower surface. Further, the clearance angle of each of the cutting edges connected to the first cutting edge may be increased with respect to the clearance angle of the first cutting edge of the main cutting edge.

[0007]

According to the above construction, the flank surface which is continuous with the main cutting edge is formed in a multi-step surface, and the cutting edge angle of the tip can be appropriately changed stepwise from the tip side to the base side of the tool body. The sharpness can be improved while ensuring the necessary cutting edge strength for each part of the cutting edge, and the chip discharge performance can be improved to reduce the cutting resistance.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, with reference to FIGS. 7 and 8, a state in which the insert according to the embodiment is mounted on a rolling tool will be described.
In these drawings, reference numeral 20 is a tip according to one embodiment, and reference numeral 22 is a tool body of an end mill. However, the illustration of the tool body 22 is simplified.

The tip 20 has a lower surface (a seating surface) 24.
Is a flat surface, and in a state where the lower surface 24 is in close contact with the chip mounting seat 26 formed on the tool body 22, the mounting surface is removably mounted by a mounting screw (not shown). In this state, the axis X of the tool body 22 is parallel to the lower surface 24. Further, a main cutting edge, which will be described later, formed on the tip 20 has its tip portion projected to the outside in the radial direction of the tool body 22 and the tip side in the direction of the axis X, and is provided with a rising amount of k1 (Fig. 8).

Next, referring to FIGS. 1 to 6, the chip 20 will be described.
The shape of will be described. The chip 20 has a rhombic plate-like appearance, and has a basic shape including a lower surface 24, an upper surface 28, and side surfaces 30 and 32 inclined with respect to these. A chip mounting hole 34 is formed in the center of the chip 20.

The upper surface 28 is separated from the lower surface 2 by the ridge 36 as a boundary.
4 and a flat surface 40 (see FIG. 3) that is connected to both sides of the flat surface 38 and that slopes upward (see FIG. 3). It's a breaker. The upper surface 28 is a rake surface, and a main cutting edge 44 is formed on the ridge portion between the upper surface 28 and the side surface 30.

The side surface (relief surface) 30 on the side exposed radially outward of the tool body 22 is a flat surface 46 connected to the lower surface 24.
And a flat surface 48 continuous with the flat surface 46, and a ridge side portion (between AB) of the flat surface 48 and the flat surface 40 is a first cutting edge 44a, and a ridge side of the flat surface 46 and the flat surface 38. The portion (the portion between BC) is the second cutting edge 44b. The first cutting edge 44a and the second cutting edge 44b form a straight line as shown in FIG. 1 when viewed from the normal direction of the lower surface 24, and when viewed from the side surface 30 side, as shown in FIG. Cutting edge 4
4a has a shape inclined upward.

Further, a flank 48 continuous with the first cutting edge 44a.
The first clearance angle α1 (see FIG. 4) formed by the second cutting edge 44b
The second clearance angle α2 formed by the flank surface 46 connected to the
It is made smaller. Then, the cutting edge angle of the main cutting edge 44 of the tip 20 having the above-described shape is more positive on the first cutting edge side than on the second cutting edge side.

The tip 20 configured as described above is attached to a tool body 22 as shown in FIGS. 7 and 8 and used as an end mill. When the work W is cut by this end mill, the cut shape of the work W is as shown in FIG. That is, the cutting surface S1 formed by the second cutting edge 44b parallel to the tool axis X has a linear cross section over the section of the length L1, and the cutting surface S2 formed by the first cutting edge 44a is larger than the cutting surface S1. It becomes a convex curved surface that is depressed outward in the direction. In this way, by making the flank 30 into a multi-step surface shape and changing the shape of the main cutting edge 44 of the tip 20 variously,
The shape of the cutting surface of the work material W can be changed to improve the accuracy of the standing wall. For example, if the main cutting edge is divided into three, the shape of the cutting surface also becomes three steps, and the shape of each section can be set variously.
Further, since the cutting edge angle can be changed according to the shape of the flank, the cutting edge strength required for each part of the main cutting edge can be secured and the sharpness can be improved.

Further, the chip shape may be a shape as shown in FIGS. The chip shown in the figure is obtained by modifying the chip shape shown in FIGS. 1 to 6 described above, and the same components are designated by the same reference numerals and the description thereof will be omitted. The tip shown in these figures differs from the tip shown in FIGS. 1 to 6 described above in the shapes of the auxiliary cutting edge 50 and the main cutting edge 44 formed at the tip of the main cutting edge 44.

The sub cutting edge 50 extends linearly in a direction substantially orthogonal to the first cutting edge 44a and is formed parallel to the lower surface 24. Further, as shown in FIG. 10, the main cutting edge 44 has the first cutting edge 4 in the normal direction of the lower surface 24.
4a is formed so as to be inclined to the inside of the chip by an angle θ with respect to the second cutting edge 44b.

When the chip as described above is attached and cut as shown in FIGS. 15 and 16, the cutting surface of the work material W by the first cutting edge 44a becomes S3 shown by an imaginary line in FIG. Therefore, by changing the angle .theta. To various values according to the cutting application, the amount of radial protrusion and the amount of squeezing of the cutting surface S3 can be set to a desired state. Also,
The sub cutting edge 50 can improve the finishing accuracy of the bottom surface.

[0018]

As described above, according to the present invention, the polygonal flat plate is formed, and the lower surface is a flat surface, and the lower surface is attached to the tip seat formed on the tool body so as to be detachably attached. In the chip to be formed, the main cutting edge is formed on the ridge portion of the side face that is the flank and the upper face that is a rake face with the breaker formed, and the flank face is,
It is formed into a multi-step surface by a plurality of continuous configuration planes,
Since the main cutting edge is composed of a first cutting edge inclined at a predetermined angle toward the lower surface and at least one or more linear cutting edges continuous with the first cutting edge, The sharpness can be improved while ensuring the necessary cutting edge strength for each part of the main cutting edge, and the chip discharge performance can be improved to reduce the cutting resistance.

[Brief description of drawings]

FIG. 1 is a plan view showing a chip according to an exemplary embodiment of the present invention.

FIG. 2 is a view of the chip of FIG. 1 as seen from the direction II.

3 is a view of the chip of FIG. 1 as seen from the direction III.

FIG. 4 is a view from the direction of the arrow IV in FIG.

5 is a view of the chip of FIG. 1 as seen from the direction V. FIG.

6 is a view of the chip of FIG. 1 as seen from the direction VI.

FIG. 7 is a side view showing a mounting state of the chips shown in FIGS. 1 to 6 on a rolling tool.

8 is a view from the direction of the arrow VIII in FIG.

FIG. 9 is a diagram showing a cutting state of a work material.

FIG. 10 is a plan view showing a chip according to another embodiment of the present invention.

11 is a view of the chip of FIG. 10 as seen from the direction XI.

12 is a view of the chip of FIG. 10 as seen from the direction XII.

13 is a view of the chip of FIG. 10 as seen from the direction XIII.

14 is a view of the chip of FIG. 10 as seen from the direction XIV.

FIG. 15 is a view showing how the chips shown in FIGS. 10 to 14 are mounted on a rolling tool.

16 is a view from the direction of the arrow XVI in FIG.

FIG. 17 is a side view showing a conventional cutting tool equipped with a tip.

FIG. 18 is a side view of the same rolling tool.

FIG. 19 is a front view of the same rolling tool.

FIG. 20 is a plan view showing a conventional chip.

21 is a view of the chip of FIG. 20 as seen from the direction XXI.

22 is a view of the chip of FIG. 20 as seen from the direction XXII.

[Explanation of symbols]

 24 Lower surface 28 Upper surface (rake surface) 30 Side surface (flank surface) 42 Breaker 44 Main cutting edge 44a First cutting edge 50 Sub cutting edge

Claims (7)

[Claims] 1. A breaker is formed in a positive throw-away tip which has a polygonal flat plate shape and whose lower surface is a flat surface and which is removably attached by abutting the lower surface against a tip seat formed on a tool body. The main cutting edge is formed on the ridge portion of the side surface that is the rake surface and the side surface that is the flank, and the flank surface is formed in a multi-step surface shape by a plurality of continuous constituent planes, The main cutting edge is composed of a first cutting edge that inclines at a predetermined angle toward the lower surface, and at least one or more linear cutting edges that are continuous with the first cutting edge. Positive throwaway tip. 2. The main cutting edge is formed in a straight line when viewed from the normal direction of the lower surface.
Positive throwaway tip as described. 3. The main cutting edge is formed by inclining the first cutting edge toward the inside of the tip with respect to the cutting edge connected to the first cutting edge when viewed in the normal direction of the lower surface. The positive throw-away tip according to claim 1. 4. The positive throw-away tip according to claim 1, wherein at least one of the cutting edges forming the main cutting edge is formed parallel to the lower surface. 5. The tip of the first cutting edge of the main cutting edge is provided with
A linear sub-cutting edge extending in a direction substantially orthogonal to the flank is formed.
The positive throwaway tip according to 3 or 4. 6. The positive throw-away tip according to claim 5, wherein the sub cutting edge is formed parallel to the lower surface. 7. The clearance angle of each of the cutting edges connected to the first cutting edge increases with respect to the clearance angle of the first cutting edge of the main cutting edge. The positive throw-away tip according to 3, 4, 5 or 6.