JPS5841060Y2 - 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 will be momentarily applied to the cutting edge of the insert, causing breakage or chipping of the cutting edge.
The depth of cut or feed rate may be limited, and excessive vibration may occur.

Since the cutting edge is straight, the chips are relatively large, and no force is applied to actively remove the chips.
There are disadvantages such as chips being trapped between the cutting edge and the workpiece, which causes chipping of the cutting edge, roughening of the cutting surface, and further reduction of cutting efficiency.

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

) is formed.

As shown in the figure, the angle formed between the upper surface 2 and each of the surfaces 4, 5.6 intersecting the upper surface 2 is set to less than 90° so that each of these surfaces 4.5, 6 serves as a relief surface. ing.

Further, in the figure, reference numeral 12 denotes 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. 5 shows the tip 1 attached to the shank 13. The tip of the shank 13 is cut out at a predetermined angle with respect to its axis to form a chip evacuation section, which is also cut out in a similar manner. A chip mounting seat 14 is formed by cutting out the chip at an angle.

The tip 1 is arranged such that the apex 0 where the cutting edge 11 and the lower surface 3 intersect is located on the central axis S of the shank 13, and the cutting edge 11 slightly protrudes in the radial direction from the outer peripheral surface of the tip of the shank 13. The chip 1 is placed on the chip mounting seat 14, and in this state, by inserting the set screw 15 into the mounting hole 12 bored in the chip 1 and screwing it into the shank 13, the chip 1 is mounted on the chip mounting seat 14. 14, the left side surface 4 and the lower surface 8 of the notch 7 are brought into contact with the two wall surfaces of the chip mounting seat 14, and the chip mounting seat 14 is pressed.
Fixed.

In this case, the arcuate surface 6, which is very difficult to bring into line or surface contact with the chip mounting seat 14 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 14. Since the lower surface 8, which can be bent, is brought into contact with the wall surface of the chip mounting seat 14, 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 13 is attached to the main shaft of an appropriate machine tool,
This is indicated by arrow A in Figure 5 (arrow B in Figure 6).
) direction.

In this case, the end mill performs interrupted cutting, and the cutting edge 11 first has a portion near the apex 0 of the workpiece (
(not shown), and then the remaining portion of the cutting edge 11 gradually bites into the workpiece, and since the cutting edge 11 has an uneven shape, the portion located on the front side in the rotational direction of the end mill, i.e. The convex part first bites into the workpiece, and then the plan view of the part 1 on the rear side, Fig. 2 is its front view, Fig. 3 is its right side view, and Fig. 4
The figure is a sectional view taken along the line IV-EV in FIG. 1.

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 substantially concave half-circle arc surface 6 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 end surface 4 and the rear end surface 5 and between the distal end surface 5 and the left side surface 4, respectively. There is.

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 chip 1 to the shank 13, as will be described later.
The mounting on the chip mounting seat 14 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 lower surface 3, and a convex curved surface 9 is formed there.

A plurality of recesses 10 are formed at the corners formed by the convex curved surface 9 and the upper surface 2, the left side surface 4, the circular arc surface 6, and the rear end surface 5, and are spaced apart from each other in the direction along the corners. The ridgeline is formed in an uneven shape.

A cutting edge 11 is formed on this uneven ridgeline.

It should be noted that in FIG.
The two wall surfaces are also similar, and a plurality of recesses 10 are formed at the corners formed by the convex curved surface 9 and the upper surface 2, the right side surface 4, the arcuate surface 6, and the tip surface 5, so that the cutting edge 11 has an uneven shape. In other words, the concave portion bites into the cutting edge 11.
No large load is applied to the device at once, and almost no vibration occurs.

Therefore, it is possible to make a deep cut and to apply a fast feed, and as a result, cutting can be carried out efficiently.

Since the cutting edge 11 has an uneven shape, the chips are divided into small pieces corresponding to the unevenness of the cutting edge 11.
Chips generated by cutting at a portion corresponding to the concave portion 10 are formed into a thin spiral shape on the inner surface of the concave portion 10, which is the rake surface of the portion. Since the cutting blade 10 is pressed against the cutting edge 10, the generated chips are discharged very well, and the cutting chips produced by the cutting blade 10 are not obstructed.

Moreover, since the notch 7 becomes a chip pocket, chips will not get stuck in the tip of the indexable insert 1.
This can prevent the portion of the cutting edge 11 near the apex 0 from being damaged.

Note that cutting by any part of the cutting blade 11 is performed during 1800 rotations after that part bites into the workpiece, so that the part near the apex 0 of the cutting blade 11 as a whole is cut into the workpiece. After the blade has bitten into the blade, cutting will be performed while the blade rotates over 180°.

If cutting is performed in this manner and one of the cutting edges 11 becomes worn, remove the set screw 15 from the shank 13,
Rotate the chip 1 by 180° with respect to the chip mounting seat 14,
The other cutting edge 11 is positioned in the same manner as the one cutting edge 11 in FIG. 5, the tip 1 is fixed to the tip mounting seat 14 with the set screw 15, and cutting is performed in the same manner as described above.

Although the recess 10 in the above embodiment has a spherical shape as shown in the figure, its shape may be arbitrary, and therefore the cutting edge 11 may have a smoothly continuous wave shape.

In addition, although the above embodiment does not specifically mention the curvature of each arcuate surface 6 and convex curved surface 9, this curvature is arbitrary and does not need to be the same in all parts. It may also be something that has changed.

As explained above, according to the indexable tip according to the invention, a plurality of recesses are formed in the corners formed by the convex curved surface, the upper surface, the negative side surface, the circular arc surface, and the other side surface, so that the ridgeline of the corner is formed into an uneven shape, and the cutting edge is formed on the ridge line of this uneven shape, so cutting progresses gradually from the center side of the cutting edge to the outer circumference, and the convex part of the cutting edge and the concave part There is a difference in the timing of biting into the workpiece depending on the part.

Therefore, the cutting load increases gradually without impacting the cutting edge, so there is no problem such as chipping or vibration of the cutting edge. It can be done quickly.

In the past, cutting chips were divided into small pieces, some of which were formed into a thin spiral shape, and were then pressed in the radial and axial directions by the convex curved surface of the cutting edge. Cutting debris is discharged extremely efficiently and does not interfere with cutting by the cutting blade.

Furthermore, since one side of the notch forms a flat surface that serves as a reference surface for mounting, the indexable insert can be attached to the tool body (shank) with high precision and firmly, and the notch also has a chip pocket. Therefore, effects such as being able to prevent chip clogging and chipping of the cutting edge can be obtained.

[Brief explanation of drawings]

Figure 1 is a plan view showing one embodiment of this invention, Figure 2 is its front view, Figure 3 is its right side view, and Figure 4 is the I of Figure 1.
5 is a plan view showing the state attached to the shank, FIG. 6 is a view taken along the VI-VI line in FIG. 5, and FIG. 7 is a section in the state attached to the shank. FIG. 1... Throwaway tip, 2...
Top surface, 3...Bottom surface, 4......- side (
right side, left side), 5...other side (tip side,
rear end surface), 6... Arc surface, 7... Notch, 8... Plane, 9... Convex curved surface, 10
・・・・・・Concavity, 11 ・・・Cutting edge.

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 Notches 7 each extending from the upper surface 2 toward the lower surface 3 and having a substantially V-shaped cross section are formed between the other side surface 5 of the set and the negative side surface 4 of the other set. A lower surface 8 is formed as a reference surface for installation 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 is directed from the upper surface 2 to the lower surface 3. It is cut off to form a convex curved surface 9, and at the corner formed by this convex curved surface 9 and the upper surface 2, the negative side surface 4, the arcuate surface 6, and the other side surface 5, there are curved surfaces spaced apart from each other in the direction along this corner. A throw-away tip characterized in that a plurality of recesses 10 are formed, the ridgelines of the corners thereof are formed in an uneven shape, and a cutting edge 11 is formed on the ridgeline forming the uneven shape.