JPH10138033A - Throw away tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throw away tip for a rotary tool such as a face milling cutter reducible of cutting resistance, excellent in chip discharging and harmless of chipping resistance. SOLUTION: A land 8 width is formed wider at the minor cutting edge 6 portion than the major cutting edge 5 portion with a face 3 formed with a slope 9, which is connected to the land 8 and formed so that not only it gradually becomes low inward but the inclination becomes steeper as it becomes more distant from the corner and its length of inclination becomes the longest at the central part of the angle side ridge of the major cutting edge 5. A breaker wall 11 erecting with an inclination is provided further inward of the slope 9 and formed so that it may be shaped in a wave along the level viewed major cutting edge 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away insert, and more particularly to a throw-away insert for a rotary tool having a rake face having an uneven surface serving as a breaker.

[0002]

2. Description of the Related Art In the case of indexable inserts incorporated in turning tools, which are continuous cutting, breaker grooves as chip control are one of the important technical issues. However, for turning tools such as face mills and end mills. In recent years, with the aim of reducing the cutting resistance and improving chip control, quite complicated uneven surfaces have been formed on the rake surface. As an example, the one disclosed in JP-A-2-95508 will be introduced here. This relates to a so-called negative type insert insert that does not have a clearance angle on the outer surface.In order to reduce the cutting force, the cutting edge must be inclined so that the center of the main cutting edge is lower than the corner. By providing the negative tip, the disadvantage of the negative tip that the axial rake angle must be set to a negative value when mounted on the rotary tool is improved, and at the same time, the width of the land is made wider at the corner portion than at the main cutting edge portion. Thus, the strength of the cutting edge at the corner is increased. A non-parallel and straight breaker wall is provided along the cutting edge to improve chip control.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to a positive-type indexable insert having a positive axial rake angle. Generally, the cutting resistance is reduced by only the positive type as compared with the negative type, but an object of the present invention is to further improve the cutting resistance to improve the cutting performance. However, simply increasing the rake angle for the purpose of suppressing the cutting resistance has a contradictory technical problem of deteriorating the fracture resistance. The present invention is intended to provide a throw-away tip that suppresses deterioration of fracture resistance and is excellent in sharpness.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is a so-called positive type throwaway in which a clearance angle is provided on an outer surface connecting a seating surface and a rake surface of a chip body. A land is formed in contact with the main cutting edge, which is the outer peripheral edge of the rake face, and a sub-cutting edge is formed at each corner of the rake face by being chamfered. In a throw-away insert for a rotary tool, wherein a corner blade formed by being rounded or formed in an arc shape is formed, the width of the land is formed wider at the corner portion than at the main cutting blade portion, and Connected to form a sloping surface that becomes gradually lower toward the inside of the rake surface, and this sloping surface is formed so that the inclination becomes steeper as it goes away from the corner, and the main cutting edge Inclined length is formed so that the maximum in the central portion of the Sumihenryo.

[0005] Further, a breaker wall that rises with an inclination is provided further inside the inclined surface of the rake surface,
Further, the present invention is characterized in that the breaker wall has a wavy shape along the main cutting edge in plan view.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 5 show a first embodiment, in which a chip body 1 has a square flat plate, and an outer surface 4 connecting a seating surface 2 and a rake surface 3 is provided with a clearance angle. This is a positive type throwaway tip composed of a flank. The outer peripheral edge of the rake face 3 becomes the main cutting edge 5, but the corner portion is cut out in a chamfered shape, and the sub cutting edge 6 is formed at the intersection of the rake face 3 and the outer face 4. Therefore, the indexable insert is generally used by being attached to a rotary tool such that the main cutting edge 5 is an outer peripheral edge and the sub cutting edge 6 is a frontal edge.
A mounting hole 7 is formed in the center of the chip main body 1 to open as a countersunk hole. The countersunk screw inserted into the mounting hole 7 allows the chip to be freely attached to and detached from the seat of the rotary tool.

The rake face 3 has a main cutting edge 5 and a sub cutting edge 6.
The land 8 is formed inscribed in the
The rake face 3 has an inclined surface 9 that gradually becomes lower inward.
Is formed. Main cutting edge 5 and sub cutting edge 6
Are at the same height, and as shown in FIGS. 3 and 4, the inclination of the inclined surface 9 is formed so as to become gradually tighter as the distance from the sub cutting edge 6 is increased. Has the maximum slope at the center of each side edge. At the same time, since the inclination length is formed to be the longest at the maximum inclined portion, the lower end of the inclination is the deepest, and therefore, the surface further on the center side than the inclined surface 9 is the same as the curved surface 10 having a concave depression. Become.

With the above-described configuration, the indexable insert of the present invention can be used as shown in FIG.
And the main cutting edge 5 has a positive rake angle in both directions perpendicular to the main cutting edge 5 as shown in FIGS. 3 and 4, so that when mounted on a rotating tool, the seating portion of the rotating tool The large rake angle added to the axial rake angle and the central rake angle has an effect on cutting. The fact that the rake angle is larger toward the center of each side ridge of the main cutting edge 5 means that the magnitude of the cutting resistance is often judged as the cutting performance of the rotary tool. The reduction will work more effectively.
Furthermore, since the width of the inclined surface 9 is the largest at the center of the main cutting edge, no excessive deformation is applied to the chips at the time of the deep cutting, and the cutting resistance generated by the chip clogging and the chip deformation is reduced. The increase is suppressed.

In machining such as face milling, a cutting edge defect frequently occurs at a corner where the main cutting edge 5 and the sub cutting edge 6 meet. Since the probability of loss of the main cutting edge 5 is relatively low, there is no inconvenience as the rake angle is improved as described above and the width of the land 8 is kept narrow while giving priority to sharpness. On the other hand, increasing the width of the land 5 at the sub-cutting edge 6 is because the land 5 at the corner where the main cutting edge 5 and the sub-cutting edge 6 intersect.
Is also widened, so that fracture resistance is enhanced.

The rake angle of the inclined surface 9 at the center of the main cutting edge is selected from the range of 5 to 40 ° depending on the work material, and the rake angle on the side of the sub cutting edge is 3 to 20 ° smaller than the rake angle. To do it. According to the results of practical tests by the present inventors, by adopting the shape as described above, for example, in cutting with a coated cemented carbide chip for alloy steel or carbon steel, the conventional rake face has unevenness in chipping resistance. Compared to a throw-away insert without any curved surface, the cutting force was smaller than some conventional throw-away inserts, which had uneven surfaces and breaker grooves on the rake face.

FIGS. 7 to 9 show a second embodiment, and the same parts as those described above are denoted by the same reference numerals.
This throw-away chip is provided with a breaker wall 11 that rises with an inclination on a curved surface 10 on a rake face 3 of a chip body 1. Also breaker wall 11
Has a wavy shape along the main cutting edge 5 in plan view. The breaker wall 11 generates a curl-like deformation without turning the chips, thereby improving the dischargeability.
Chips and breaker wall 1 due to the wavy shape
1 is a point contact, so that an increase in cutting resistance due to the contact is minimized. The J-shape on the rake face 3 is a simple pattern formed by a very shallow depression from the surface.

FIG. 10 shows a third embodiment, and the same parts as those described above are denoted by the same reference numerals. This indexable insert differs from the second embodiment in the shape of the corner. That is, the corner blades 12 rounded in an arc shape are formed at four corners,
Also in such an embodiment, the probability of loss at the corner blade 12 and at the connection between the corner blade 12 and the main cutting blade 5 is high. Thus, the width of the land 8 is formed wider at the corner blade 12 than at the main cutting blade 5 to prevent loss.

[0013]

The indexable insert according to the present invention forms a substantially larger rake angle than the mounting angle of the rotary tool to reduce cutting resistance and suppress increase in contact resistance with chips. Chips with excellent dischargeability are discharged by the formed breaker wall, and lands having different widths at the main cutting edge and the corner portion improve fracture resistance while maintaining good sharpness.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 4 is an enlarged sectional view taken along the line BB of FIG. 1;

FIG. 5 is a sectional view taken along line CC of FIG. 1;

FIG. 6 is a perspective view showing a second embodiment of the present invention.

FIG. 7 is a plan view of FIG. 6;

FIG. 8 is an enlarged sectional view taken along line DD of FIG. 7;

FIG. 9 is an enlarged sectional view taken along line EE of FIG. 7;

FIG. 10 is a plan view showing a third embodiment of the present invention.

[Explanation of symbols]

 3 Rake surface 5 Main cutting edge 6 Secondary cutting edge 8 Land 9 Inclined surface 10 Curved surface 11 Breaker wall 12 Corner blade

Claims (3)

[Claims] 1. A clearance angle is given to an outer surface 4 connecting a seating surface 2 and a rake surface 3 of a chip body 1 forming a polygonal flat plate, and the rake surface 3 has a main cutting edge 5 as an outer peripheral edge. A land 8 is inscribed in the rake face 3 and each corner of the rake face 3 has a sub-cutting edge 6 cut in a chamfered shape or a rotary tool having a corner blade 12 rounded in an arc shape. In the indexable insert, the width of the land 8 is smaller than that of the main cutting edge 5 by the auxiliary cutting edge 6.
Alternatively, the rake face 3 is formed with a wide width at the corner blade 12, and the rake face 3 is formed with an inclined surface 9 which is connected to the land 8 and gradually lowers inward, and the inclined surface 9 is gradually moved away from the corner portion. A throw-away insert characterized in that the inclination is formed to be steep and the inclination length is formed to be the longest at the center of the corner edge of the main cutting edge 5. 2. Inside the inclined surface 9 provided on the rake surface 3, furthermore, a breaker wall 11 rising up with an inclination.
The indexable insert according to claim 1, wherein a tip is provided. 3. The main cutting edge 5 in a plan view is provided on the breaker wall 11.
The throw-away tip according to claim 2, wherein the tip has a wavy shape along the axis.