KR20060135212A - Cutting insert - Google Patents

Abstract

A cutting insert is provided to improve processing precision without an additional apparatus for adjusting the position of the cutting insert by directly assembling the cutting insert with a milling cutter, and to use the cutting insert at both sides by forming cutting blades in upper and lower parts. A polygonal cutting insert(100) includes an upper surface(20), a lower surface(30) having a support surface(25) placed in a support part of a cutter and a sides(40) surrounding the upper surface and the lower surface. The perpendicular processing cutting insert has a cutting blade(50) formed between the upper surface and the side. The cutting blade is inclined downward at both ends around a virtual straight line for a side of a polygon. A center of the cutting blade is formed of a curve around the center of the cutting insert or a virtual straight line for the polygonal side. The support surface is formed of a horizontal plane, and the side is vertically formed to the support surface.

Description

Cutting insert

1 is a perspective view showing a triangular cutting insert of the conventional wedge coupling method.

FIG. 2 is a perspective view of the cutting insert shown in FIG. 1 coupled to the milling cutter in a wedge manner. FIG.

Figure 3 is a perspective view showing a triangular cutting insert of the conventional screw coupling method.

4 is a perspective view showing that the cutting insert shown in FIG. 3 is coupled to the milling cutter in a threaded manner;

Figure 5 is a perspective view of a rectangular cutting insert of the conventional threaded method.

6 is a perspective view showing that the cutting insert shown in FIG. 5 is coupled to the milling cutter in a threaded manner;

7 is a perspective view of a cutting insert according to the present invention.

8 is a front view of a cutting insert according to the present invention.

9 is a plan view of a cutting insert according to the invention.

10 is a perspective view showing that the cutting insert according to the invention is coupled to the milling cutter in a threaded manner.

<Description of the symbols for the main parts of the drawings>

100: cutting insert 20: upper surface

25: support surface 30: lower surface

40: side 50: cutting edge

55: rake surface 60: fastening hole

FIELD OF THE INVENTION The present invention relates to cutting inserts for use in cutting tools, and more particularly to cutting inserts for milling, in particular right angle, for ease of use.

In general, milling refers to processing steel or cast iron by a cutting insert that is coupled to a rotating cutting tool or a cutter, and the cutting insert (hereinafter referred to as 'insert'). Is usually made of cemented carbide.

The insert is generally formed in a polygonal shape and is provided with a cutting edge for cutting only between the side and the upper surface, and the lower surface forms a support surface on which the insert is supported by the cutting tool.

Hereinafter, a conventional insert for right angle machining will be described with reference to FIGS. 1 to 6.

1 to 2, the conventional wedge clamp type insert 1 includes a lower surface 3 and an upper surface 2 serving as reference surfaces, and the lower surface and the upper surface. It consists of three sides 4 surrounding the face.

Here, a cutting edge 5 is provided between the upper surface 2 and the side surface 4, the cutting is made through the cutting edge. In addition, the angle formed by the side surfaces and the bottom surface is formed larger than the right angle so that the cutting edge has a positive cutting angle.

The insert 1 shown in FIG. 1 has three cutting edges 5, which are first engaged with a locator 11 and then pockets 13 formed at predetermined angular intervals at the outer periphery of the milling cutter 10. It is seated on). Thereafter, the locator 11 and the insert 1 are fixedly coupled to the milling cutter 10 by a wedge 12.

Of course, FIG. 2 shows that the insert 1 is coupled to the milling cutter 10 through the locator 11, but the insert may be directly coupled to the milling cutter without passing through the locator.

After that, the milling cutter 10 is rotated in the R direction with respect to the central axis 15, and the right angle processing through the cutting edge.

As shown in FIGS. 3 to 4, the conventional screw on type insert 1 includes a lower surface 3 and an upper surface 2 serving as reference planes as in the conventional insert described above. It consists of three sides 4 surrounding the lower and upper surfaces. However, unlike the conventional insert described above, the fastening hole 6 for screwing is further provided at the center portion.

The insert 1 can be screwed into the locator first and then fixedly coupled to the pocket 13 of the milling cutter. In FIG. The coupling through 14 is shown.

In this case, the process of cutting is the same as the process described with reference to FIGS. 1 and 2.

5 to 6 show a rectangular insert 1 of a conventional insert. As shown in the drawing, the rectangular insert 1 has a quadrangular shape, and two cutting edges 5 are provided between the upper surface 1 and the side surfaces 4, and the side edges 4 having the cutting edges are provided. ) Is formed longer than the side surface 7 without a cutting edge.

In addition, the angle between the side surface 4 and the lower surface 3 is formed larger than the right angle so that the cutting edge 5 is a positive cutting angle, the cutting edge 5 is the lower surface ( The thickness of the part where the cutting is made thicker based on 3) is formed in an oblique form, and strength reinforcement is made.

The insert 1 is coupled through the milling cutter 10 and the screw 14 through the fastening hole 6 formed in the center as shown in Figure 6, the machining through the milling cutter is the same as described above It is done.

As described with reference to FIGS. 1 to 6, the conventional right angle insert has a triangular shape. That is, in the case of a triangular shape, since three cutting edges are provided, it uses more than a rectangle. Of course, if a very high cutting resistance is required due to its geometrical shape, a rectangular insert may be used, and other types of polygonal inserts may also be used.

The above-mentioned conventional inserts are coupled to a milling cutter by a method of directly inserting an insert into a milling cutter and a method of joining the milling cutter to a locator and then joining the milling cutter. The latter is called indexable clamp type.

In the case of the direct coupling method, the insert can be easily combined and disassembled with the milling cutter, and the coupling and disassembly takes less time, but it is very difficult to adjust the position of the insert.

On the other hand, in the case of the indexable coupling method, since the insert is coupled to the locator and then coupled to the milling cutter, the coupling and disassembly takes a long time. However, by adding the position adjusting device of the insert to the locator, It has the advantage of being able to enable precise machining.

Therefore, in the case of taking the direct joining method instead of the indexable type insert joining method, there is a need for an insert capable of satisfying the required machining precision without a separate device for adjusting the position of the insert.

On the other hand, conventional inserts for right angle machining have cutting edges provided only between the upper surface and the side surface, so that the durability is shortened. Therefore, there is a need for a cutting insert having a cutting edge not only on the upper surface but also on the lower surface, so that both sides can be used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an insert which enables more precise machining, and to provide an insert that is easy to use by increasing durability.

In order to achieve the above object, the present invention comprises a top surface, a lower surface with a support surface that is seated on the support of the cutter and a polygonal cutting for polygonal processing is made including a side surface surrounding the upper surface and the lower surface. In the insert, a cutting edge is provided between the upper surface and at least one or more of the side surfaces, wherein the cutting edges are inclined downward in the horizontal direction from the center to both ends with respect to an imaginary straight line forming the sides of the polygonal shape. Provided is a cutting insert for shoulder machining in a shape.

Here, the center of the cutting edge may be a portion having a curve having a predetermined radius of curvature with respect to the center of the cutting insert or a portion of an imaginary straight line forming the sides of the polygonal shape.

In addition, the downwardly inclined shape of the cutting insert may be formed of at least one curved line or at least one straight line, and the support surface is preferably a horizontal plane, and the side surface is perpendicular to the support surface. Do.

On the other hand, the upper surface may further include a rake surface between the cutting edge and the support surface inclined downward toward the support surface from the cutting edge to discharge the cut chips, the lower surface and the upper surface The lower surface and the center of the upper surface may be made of a triangular shape that can be used on both sides symmetrical with respect to the virtual horizontal plane.

In addition, a fastening hole for coupling with the cutter is provided at the center of the insert, and the insert and the cutter may be screwed.

In addition, at least two or more side surfaces at which cutting is not currently performed may be provided with an auxiliary support surface seated on the side support of the cutter. This side support is to prevent the insert from rotating during cutting.

Hereinafter, an insert according to the present invention will be described in detail with reference to the accompanying drawings.

7 is a perspective view of a cutting insert according to the present invention, and FIG. 8 is a front view of the cutting insert according to the present invention.

As shown in FIGS. 7 and 9, the insert according to the present invention has an upper surface 20, a lower surface 30 having a support surface seated on a support of a milling cutter, and a side surface surrounding the upper surface and the lower surface. Including 40. In addition, the polygonal shape of the insert is determined according to the number of the side surfaces, in which a triangular insert 100 having three sides is shown.

In addition, a cutting edge 50 is provided between the upper surface 20 and the at least one side surface 40. Here, the cutting edge is in direct contact with the workpiece to perform the function of cutting the workpiece.

Preferably, the insert 100 is symmetrical with respect to the virtual horizontal plane in the center between the upper surface 20 and the lower surface 30. Here, the upper surface and the lower surface are symmetrical with each other. Therefore, the cutting edge 50 and the support surface 25 are also formed symmetrically on the upper surface and the lower surface, respectively.

Therefore, the support surface is provided on the lower surface 30 corresponding to the support surface 25 of the upper surface 20, and the surface supported by the cutting tool is changed as the insert is turned upside down.

On the other hand, the support surface 25 is preferably a horizontal plane of a single plane. This is because it consists of a horizontal plane that is a single plane is easy in the machining surface for insert manufacturing and cutter manufacturing, it is easy to disperse reaction forces generated during cutting. It is also suitable for a symmetrical structure for enabling the insert to be used on both sides.

Here, the support surface 25 may be formed of a plurality of horizontal planes that are radially symmetric with respect to the center of the insert. FIG. 7 shows, for example, that these support surfaces 25 are formed at three of the upper surfaces 20 of the insert.

In addition, the side surfaces 40 may be formed to be perpendicular to the support surface 25 so as to be connected to the upper surface 20 and the lower surface 30. That is, a cutting edge is provided between the side surfaces and the upper surface or the lower surface, preferably at right angles to increase the strength of the cutting force transmitted through the cutting edge.

Here, the side surface 40 is preferably configured to increase the area toward both ends as shown in FIG. This is because a cutting force is applied to the cutting edges respectively provided on the upper and lower portions of both end portions of the side surface during machining. Therefore, in order to reinforce strength with respect to the portion where the cutting force is large, it is preferable that the central portion of the side surface is formed relatively thin and both ends are relatively thick.

Since the insert according to the invention is also aimed at being able to use on both sides, the cutting edges are provided on the upper and lower surfaces, and the precision of the support surface 25 on which the insert is supported by the cutting tool is very important.

That is, in the case of a cross-section insert, when the surface corresponding to the support surface of the upper surface is damaged by machining, it does not directly affect the machining precision. However, in the case of a double-sided insert, when the support surface is damaged, the support surface is damaged when it is turned over and processed through another surface, so that the position of the insert may be changed, thereby affecting the machining precision.

Therefore, the insert according to the present invention preferably further comprises a rake surface 55 inclined downward from the cutting edge toward the support surface.

Here, the chip cut through the cutting edge is discharged through the rake surface. That is, even if the rake surface is damaged by the chip is discharged, it is possible to minimize the effect of the chip on the support surface (25).

In addition, it is preferable that the inclination angle of the rake surface is approximately 5 ° to 15 ° with respect to the support surface 25 which is the horizontal plane in order to have a positive axial angle. That is, the cutting is made at a positive angle within the above range to facilitate the discharge of the chip. However, if the inclination angle of the rake surface is further increased, the strength of the cutting edge may be weakened. If the inclination angle is made smaller, the positive clearance angle must be maintained at a predetermined angle, so the cutting is performed at a negative angle. This can be done.

On the other hand, between the rake surface and the support surface may be provided with a step forming a constant height difference. In other words, a constant step portion may be formed between the rake surface and the support surface. It will be apparent that the chip discharged through the rake surface through the stepped portion can further reduce the influence on the support surface.

And, the insert according to the present invention is preferably provided with a fastening hole 60 in the center in order to be coupled to the cutting tool. The fastening hole is formed perpendicular to the seating surface 25, through which the insert can be screwed with the milling cutter. Of course, it would also be possible to be secured by a wedge to the cutting tool.

Hereinafter, the shape of the cutting edge of the insert according to the present invention will be described in detail with reference to FIG. 9, and FIG. 9 illustrates a plane of a triangular insert as an example, and may be any polygonal insert.

The enlarged portion shown in FIG. 9 represents the cutting edge 50 portion. Here, the triangular insert 100 has a cutting edge is formed on each of the three sides of the upper and lower, the triangle is preferably an equilateral triangle so that the cutting edge can be used alternately. Therefore, the portion shown by the dotted line represents an imaginary straight line (hereinafter referred to as 'dotted line') of the sides of the equilateral triangle.

Here, the cutting edge of the insert according to the present invention is preferably formed in a shape that converges toward the center of the insert toward both ends from the center with respect to the dotted line which is an imaginary straight line forming the sides of the triangular shape, for example.

In other words, in the enlarged view shown in FIG. 9, the cutting edge has a shape inclined upward toward the center of the insert toward both ends with respect to the dotted line. Of course, in this case, the center of the insert is located above the dotted line, and when the insert is rotated so that the center of the insert is located below the dotted line, the cutting edges move toward both ends of the dotted line. It is made of a shape inclined downward toward the center of the insert.

When the insert is mounted on a cutting tool, that is, a cutter, the cutting is performed with one cutting edge, it is preferable that two neighboring side surfaces are seated and supported by the side support of the cutter. That is, the side of the cutter is preferably provided with an auxiliary support surface which is seated on the side support of the cutter.

By the support through such an auxiliary support surface it is possible to prevent the insert from being rotated during the cutting process to increase the processing precision.

In the perpendicular processing, the cutting edge of the insert is formed in the outer peripheral portion of the cutter in parallel with the axis of rotation of the cutter. Here, by the rotation of the cutter the cutting edge is to process the side of the workpiece perpendicular to the horizontal plane.

Therefore, in order to assure maximum machining accuracy close to the ideal orthogonal machining, the insert should be coupled to the cutter such that the cutting edge of the insert is parallel to the axis of rotation of the cutter. In other words, the angle of the cutting edge should be coupled perpendicular to the horizontal plane of the workpiece.

This vertical degree is closely related to the geometric precision of the side support of the cutter and the auxiliary support surface of the insert seated on the side support.

In other words, if an error occurs in a portion supporting the side of the insert, the verticality of the cutting edge loses the precision, thereby lowering the machining accuracy. Of course, as described above, a separate device for finely adjusting the position of the cutting edge may be provided, but the present invention can improve the precision of the cutting edge geometry.

For example, when the cutting edge is in a straight line when the cutting edge is viewed in a plane, when the insert is inclined at a predetermined angle to be coupled to the cutter, that is, the cutting edge has a certain error angle and is larger than the horizontal plane of the workpiece and perpendicular to the workpiece. When combined at small angles, the error angle directly affects machining accuracy.

However, when the cutting edge is not made in a straight line but converges toward the center of the insert from the center to both ends of the straight line, the effect of the error angle can be offset.

Here, it is preferable that the side surface constituting the center of the cutting edge is an auxiliary support surface seated on the side support of the cutter as a single plane. That is, it is preferable that the side support of the insert is also symmetrical due to the characteristics of the milling process. In this case, the center of the cutting edge becomes a part of the dotted line.

Of course, the center of the cutting edge may be made of a curve having a predetermined radius of curvature. In other words, it has a predetermined radius of curvature at the center of the insert. In this case, however, the side support of the cutter supporting the side of the insert also needs to be machined to fit the curved shape.

On the other hand, the cutting edge portion converged toward the center of the insert 100 with respect to the center of the cutting edge 50 may be made of a curved line, it may be made of a straight line having a predetermined angle with the dotted line. Of course, it would also be possible to combine curves and straight lines.

9 shows that the cutting edge 50 has a predetermined angle a with respect to the dotted line which is an imaginary straight line, and a straight line having the angle a is possible.

Here, the radius of curvature of the curve forming the cutting edge and the angle formed by the dotted line should be appropriately selected in consideration of the size of the insert and the rotation radius of the cutter to which the insert is fixed. In this case, when the radius of curvature is made too small or the angle is made too large, the machining error is increased, and in the opposite case, the purpose of the cutting edge shape is canceled.

Accordingly, the radius of curvature of the cutting edge is generally preferably R100 to R800, and the angle that the cutting edge and the dotted line can make is preferably 0.5 ° to 3 °.

On the other hand, the cutting edge of this shape can reduce the error that may occur when the insert is seated and coupled to the side support of the cutter.

That is, the whole side surface of the insert does not become an auxiliary support surface seated on the side support portion of the cut, but only the center portion of the side surface can be the auxiliary support surface. And the auxiliary support surface can be configured in a single plane.

Therefore, when the cutting edge and the side portion are damaged by machining through the cutting edge, when the machining is to be processed through the other cutting edge, the area that is damaged and may cause an error when combined with the auxiliary support surface of the cutter is reduced. As a result, the machining accuracy can be improved. That is, since a constant gap is formed between both end portions of the side surface and the side support portion of the cutter, even if the damaged portion can be minimized the effect of causing an error when the insert is coupled.

Hereinafter, the use of the insert according to the present invention will be described in detail with reference to FIG. 10.

10 is a perspective view showing that the insert according to the invention is coupled to the milling cutter in a threaded manner.

First, the insert 1000 is coupled to a pocket 210 formed at a predetermined angle on the outer periphery of the milling cutter 200 such that the cutting edge portion is horizontal to the axis of rotation of the milling cutter, wherein the support surface of the insert is It is seated on the support 220 of the milling cutter, and the auxiliary support surface of the insert is seated on the side support 230 of the milling cutter, after which the female thread formed in the fastening hole 60 and the support of the insert ( The insert 100 is fixed to the milling cutter 100 by inserting the screw 240 into the 260.

As the milling cutter rotates in the R direction with respect to the rotary shaft 250, the workpiece is cut through the cutting edge of the insert.

The present invention is not limited to the above-described embodiments, and those skilled in the art can make modifications without departing from the spirit of the present invention, and such modifications are within the scope of the present invention.

According to the present invention described above,

First, it is possible to provide a cutting insert that satisfies the required machining precision in the case of directly inserting the insert into the milling cutter without the need for a separate device for adjusting the position of the insert.

Second, it is possible to provide a cutting insert that is provided on both sides as well as the upper surface as well as the lower surface.

Claims (9)

In the cutting insert for polygonal orthogonal shape machining comprising an upper surface, a lower surface with a supporting surface seated on the support of the cutter and side surfaces surrounding the upper surface and the lower surface, A cutting edge is provided between the upper surface and the at least one side; The cutting edge is a cutting insert for forming a right angle machining formed in the shape inclined downward in the horizontal direction toward the both ends from the center with respect to the imaginary straight line constituting the sides of the polygonal shape. The method of claim 1, And a center portion of the cutting edge is a portion having a predetermined radius of curvature with respect to the center of the cutting insert or a portion of an imaginary straight line forming the sides of the polygonal shape. The method according to claim 1 or 2, The inclined cutting insert of the cutting edge is formed of at least one curved line or at least one straight line. The method of claim 3, wherein Cutting support for a perpendicular processing, characterized in that the support surface is a horizontal surface. The method of claim 4, wherein And said side surface is perpendicular to said support surface. The method of claim 5, The upper surface is, And a rake surface disposed between the cutting edge and the support surface inclined downward from the cutting edge toward the support surface to discharge the cut chips. The method of claim 6, The cutting insert for square processing, The lower surface and the upper surface is a cutting insert for orthogonal machining, characterized in that the triangular shape is symmetrical to each other based on the virtual horizontal plane of the center of the lower surface and the upper surface can be used on both sides. The method of claim 7, wherein The cutting insert for a right angle machining is a cutting insert for a right angle machining, characterized in that the fastening hole for coupling with the cutter at the center portion. The method of claim 1, At least two side surfaces are provided with an auxiliary support surface which is mounted to the side support portion of the cutter.

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