JPS5841061Y2 - Throwaway tip - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an indexable tip for use in cutting, and particularly to an indexable tip for use in a milling cutter such as an end mill.

Conventionally, various tools such as bits, milling cutters, and drills have been used to cut metal, but with the advancement of technology related to cemented carbide, cemented carbide tips have been used as the cutting edge of the tools mentioned above. has come to be used.

This cemented carbide insert has less hardness loss at high temperatures than cutting edges made of other materials, and has excellent wear resistance, but it is expensive, so it is formed as a small piece and is not attached to the tool body. Generally, they are detachable and replaceable.

By the way, most of these conventionally used tips have straight cutting edges formed on appropriate ridge lines, and the same is true for tips for end mills. In a conventional end mill, one or more chips are attached to the shank so that the cutting edge is in line with the radial direction of the end mill, and the tip is rotated from the center of rotation to the outer circumference every half rotation. All of the cutting blades up to the part cut into the object to be cut at the same time.

Therefore, there is a risk that a large impact force is instantaneously applied to the cutting edge of the insert, causing breakage or chipping of the cutting edge, and vibration of the housing becomes large, making it impossible to perform good cutting.

Furthermore, since the cutting edge is straight, the chips are relatively large and there is no force acting on the chips to actively remove them. Therefore, when cutting, the chips get entangled with the tool. , or it may get caught between the cutting edge and the workpiece, which may cause chipping of the cutting edge, roughness of the cutting surface, or
Furthermore, there are drawbacks such as a decrease in cutting efficiency.

This invention was made in view of the above circumstances, and the purpose is to provide an indexable insert that has improved cutting performance and improved chip evacuation.

An embodiment of this invention will be described below with reference to the drawings.

Furthermore, Figure 1 shows the indexable tip (
Hereinafter, it may be abbreviated as a chip.

) 1 is a plan view, FIG. 2 is a front view thereof, and FIG. 3 is a left side view thereof.

The whole chip 1 is formed into a flat plate shape, and between its upper surface 2 and lower surface 3, there is a negative side surface 4 and a negative side surface 4.
Another side surface 5 formed at a predetermined interval in the circumferential direction from
and a half-time circular arc surface formed from the side surface 4 to the other side surface 5 in a symmetrical manner.

For convenience of explanation, in the following, the negative side surface 4 on the right side in FIG. The - side surface 4 is referred to as the left side surface 4, and the other side surface 5 that is in the same group as this left side surface 4 and is located on the upper end side is referred to as the rear end surface 5.

A cutout 7 having a substantially V-shaped cross section extending from the upper surface 2 toward the lower surface 3 is formed between the right side surface 4 and the rear end surface 5 and between the front end surface 5 and the left side surface 4, respectively. .

Of the two wall surfaces that define the notch 7 formed between the right side surface 4 and the rear end surface 5, that is, the notch 7 located above in FIG. has been done.

This lower surface 8 connects the tip 1 to the shank 12 as will be described later.
The mounting on the chip mounting seat 13 is performed using a reference surface.

On the other hand, the intersection between the wall surface on the rear end surface 5 side and the upper surface 2 is cut off from the upper surface 2 toward the center of the wall surface, and a convex curved surface 9 is formed there.

A cutting edge 10 is formed on the ridge formed by the convexly curved surface 9 button, the upper surface 2, the left side surface 4, the arcuate surface 6, and the rear end surface 5.

Note that the notch 7 on the lower side of FIG. ing.

In addition, as shown in the figure, the angle formed by the upper surface 2 and the convex curved surface 9 and the above-mentioned surfaces 4, 5.6 that intersect with these is less than 90° so that each of these surfaces 4.5.6 serves as a relief surface. is set to .

Additionally, reference numeral 11 in the figure is a mounting hole drilled in the center of the chip 1, and the upper surface 2 side of the mounting hole is counterbore.

Next, a case will be described in which the indexable tip 1 formed as described above is used in an end mill.

FIG. 4 shows the state in which the tip 1 is attached to the shank 12. The tip of the shank 12 is cut out at a predetermined angle with respect to its axis to form a chip evacuation part, and this part is also cut out in a similar manner. A chip mounting seat 13 is formed by cutting out the chip at an angle.

The tip 1 has an apex 0 where one cutting edge 10 intersects with a wall surface adjacent to the convex curved surface 9 of the notch 7, and the apex 0 is located on the central axis S of the shank 12, and this apex O is defined as one end. The cutting blade 10 is placed on the tip mounting seat 13 so as to slightly protrude from the outer peripheral surface of the tip of the shank 12 in the radial direction, and in this state, the set screw 14 is inserted into the mounting hole drilled in the tip 1. 11 and insert it into the shank 1.
2, the chip 1 is attached to the chip mounting seat 1.
3, and is fixed to the chip mounting seat 13 with the left side surface 4 buttons and the flat surface 8 of the notch 7 in contact with the two wall surfaces of the chip mounting seat 13.

In this case, the arcuate surface 6, which is very difficult to bring into line or surface contact with the chip mounting seat 13 and is easily brought into point contact, can be easily brought into line or surface contact without abutting against the wall surface of the chip mounting seat 13. Since the lower surface 8, which can be bent, is brought into contact with the wall surface of the chip mounting seat 13, it is possible to improve the accuracy and strength of the mounting of the indexable chip 1.

When cutting with an end mill configured in this way, the shank 12 is attached to the main shaft of an appropriate machine tool,
This is indicated by arrow A in Figure 4 (arrow B in Figure 5).
) direction.

In this case, the cutting edge 10 near the apex O of the housing is the workpiece (
(not shown), and then the remaining part of the cutting edge 10 gradually bites into the object to be cut and cuts it. Therefore, no large impact force is applied to the cutting edge 10, and therefore, the cutting edge 10 is damaged. There is no risk of chipping or chipping.

Moreover, since the angle between the convex curved surface 9 and the wall surface adjacent to the convex curved surface 9 of the notch 7 is an obtuse angle, the strength of the portion near the apex O of the cutting edge 100 is improved, thereby preventing chipping of the cutting edge 10. This can be prevented even more reliably.

By the way, if you move the lower surface 3 parallel to the upper surface 2 side and make the chip 1 into a shape such that the lower surface 3 includes the apex O, the apex 0
The angle of the portion becomes an acute angle, and the portion near the apex O of the cutting edge 10 is likely to be damaged.

In addition, the generated chips are guided toward the rear of the end wheel in the radial and axial directions along the convex curved surface 9, so that they are smoothly and quickly discharged.

Moreover, since the discharge of chips in this case is due to the free induction action by the convex curved surface 9 of constant curvature, it does not cause chatter vibration of the end mill.

Furthermore, since the notch 7 serves as a chip pocket, chips do not become lodged in the tip of the chip 1, thereby making it possible to more reliably prevent the portion of the cutting edge 10 from being damaged near the apex O.

In addition, if one cutting edge 10 is worn, set screw 1
4 from the shank 12, rotate the insert 1 1800 rotations with respect to the insert mounting seat 13, position the other cutting edge 10 in the same manner as one cutting edge 10 in FIG. It is fixed to the mounting seat 14 and cut in the same manner as described above.

As explained above, according to the indexable insert according to this invention, the cutting edge is formed on the ridge formed by the convex curved surface, the upper surface and the - side surface, the circular arc surface, and the other side surface, so that the cutting load is reduced. Since the cutting edge gradually increases without any impact acting on the cutting edge, chipping of the cutting edge can be prevented.

Moreover, since the chips generated by the cutting blade are guided by the convex curved surface, they are smoothly discharged without getting stuck between the cutting blade and the workpiece.

Since the convex curved surface is formed from the top surface of the housing toward the center of the wall surface on the other side of the notch, the angle between the convex curved surface and the wall surface is an obtuse angle, and the notch forms a chip pocket. Since chip clogging can be prevented, breakage of the cutting edge can be more reliably prevented.

Further, since a plane serving as a reference surface is formed on the wall surface on the negative side of the notch, effects such as the ability to accurately and firmly mount the indexable tip can be obtained.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of this invention, Fig. 2 is a front view thereof, Fig. 3 is a left side view thereof, Fig. 4 is a plan view showing the state in which it is attached to a shank, and Fig. 5 is a plan view thereof. V-V in Figure 4
A view taken along the line, and FIG. 6 is a partial sectional view showing the button attached to the shank. 1... Throwaway tip, 2...
Top surface, 3...Bottom surface, 4......- side (
right side, left side), 5...other side (tip side,
(rear end surface), 6...Circular surface, 7...Notch, 8...Bottom surface, 9...Convex curved surface, 10...
...cutting blade.

Claims (1)

[Scope of utility model registration request] The whole has a flat plate shape, and between the upper surface 2 and the lower surface 3, there is a − side surface 4, another side surface 5 formed at a predetermined interval in the circumferential direction from this − side surface 4, and these − side surfaces 4. It has two pairs of half-circular arc surfaces 6 formed from the side surface 5 to the other side surface 5 symmetrically, and between the − side surface 4 of one pair and the other side surface 5 of the other pair, and Cutouts 7 each extending from the upper surface 2 toward the lower surface 3 and having a cross-sectional shape of a square letter are formed between the other side surface 5 of the set and the minus side surface 4 of the other set. A lower surface 8 that serves as a reference surface for installation is formed on the wall surface on the - side 4 side of the defining wall surface, and the intersection between the wall surface on the other side 5 side and the upper surface 2 extends from the upper surface 2 to the center of the wall surface. A convex curved surface 9 is formed there by cutting off toward the
A throw-away tip characterized in that a cutting edge 10 is formed on the ridge formed by the convex curved surface 9, the upper surface 2, the negative side surface 4, the arcuate surface 6, and the other side surface 5.