JPH0418724Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a round throw-away tip.

[Prior art]

Conventionally, a circular plate-shaped throw-away tip 1 as shown in FIGS. 8 and 9 has been known. This round throw-away tip 1 has advantages such as high cutting strength due to its long cutting edge and a large number of usable corners, so it is used in a wide range of applications from cutting tools to cutters. When this round throw-away tip 1 is attached to the tool body (end mill body) 2 shown in FIGS. 6 and 7, the rotation center axis 3 and the tip 4 of the throw-away tip 1
They are separated by the distance E shown in the figure. The distance E can be made small enough to prevent the non-cutting part of the throw-away tip 1 from interfering with the workpiece while the end mill body 2 is rotating, and the number of teeth is generally
When the amount is large, it is said to have multiple blades, and when it is small, it is said to be single blade.

[Problems to be solved by the invention] However, in the conventional circular throw-away tip 1, since the outer circumference is circular,
For example, when cutting is performed by attaching this throw-away tip 1 to the end mill body 2 shown in Fig. 6, since the outer shape is circular, a force is applied to turn the throw-away tip 1 in the circumferential direction. Since the seating of the throwaway tip 1 is poor, it is necessary to use a clamping member 6 in addition to the mounting member 5 to increase the clamping strength of the throwaway tip 1 and improve the accuracy of the throwaway tip 1. is poor, the number of parts increases,
In addition, since the cutting edge is round, the length of the cutting edge is long, and because the cutting edge is subjected to a large impact due to interrupted cutting at once, there is a problem that the cutting edge is easily damaged or chipped.

In addition, the throw-away tip 1 during cutting
The cutting speed differs between the tip of the tip and the maximum cutting radius around the rotation center axis 3, which has a great effect on cutting performance. This problem is especially large when the amount of deviation (distance E) is small.

In addition, the smaller the amount of deviation (distance E) between the center of rotation axis 3 of the tool body 2 and the center of the throw-away tip 1, the slower the chip evacuation work will be. There was also a problem in that the tip of the throw-away tip 1 was easily damaged, especially the tip of the throw-away tip 1.

The object of the present invention is to provide a throw-away tip that solves the above-mentioned drawbacks of conventional tips.

[Means for solving problems]

The present invention has been made to solve the above-mentioned problems, and in a circular plate-shaped throw-away chip with a circular outer periphery, a A notch is formed which reaches the upper surface and has a substantially V shape when viewed in plan from a direction perpendicular to the top surface, and one wall surface of this notch is located at the intersection of the one wall surface and the outer periphery in plan view. formed into an inclined surface that gradually slopes toward the other wall surface of the notch with respect to a diameter line passing through the intersection of the one wall surface and the outer periphery of the throwaway chip as it goes toward the inner peripheral side, The intersection between one wall surface of the notch and the top surface is formed into a convex curved surface that smoothly continues with the one wall surface and the top surface when viewed from the outer circumferential side of the throw-away chip. This is a characteristic feature.

Note that the diameter line of the throw-away tip here refers to a straight line that passes through the center of the arc of the circularly formed outer periphery, and the diameter line that passes through the intersection of one wall surface of the notch and the outer periphery is There is only one of each for each chip.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. Reference numeral 11 in FIG. 1 is a round throw-away chip (hereinafter referred to as a chip), and this chip 11 has a circular outer circumference 12 and an upper surface 13.
It consists of a flat plate with a lower surface (bottom surface) 14 parallel to each other.

The chip 11 may be of a positive type, in which the outer periphery 12 forms an acute angle with the upper surface 13, as shown in FIG.

At the position dividing the outer periphery 12 of the chip 11 into three equal parts,
A plan view (first
Notch 1 that is approximately V-shaped in Figure 3A)
5 is formed. As a result, three cutting edges 16, 17, and 18 are formed on the outer periphery 12. As shown in FIG. 3A, one wall surface 19 of the notch 15 is located at the intersection 2 of the one wall surface 19 and the outer periphery 12 in a plan view from a direction perpendicular to the upper surface 13.
As you go from 0 to the inner circumferential side, the chip 11
The notch 15 is formed into an inclined surface that gradually slopes toward the other wall surface 23 side with respect to the diameter line 21 passing through the intersection 20 . In addition, the diameter line 21
is a straight line passing through the arc center P of each cutting edge 16, 17, 18.

Further, as shown in more detail in FIG. 2, the intersection between the wall surface 19 and the upper surface 13 of the chip 11 is smoothly continuous with the one wall surface 19 and the upper surface 13 when viewed from the side from the outer periphery 12 side of the chip 11. It is formed into a convex curved surface 22. In forming this convex curved surface 22, a stepped portion 24 is formed on the upper surface 13 by extending the other wall surface 23 of the notch 15. The angle between the wall surface 23 and the tangent to the outer periphery 12 is an obtuse angle, and the intersection between the wall surface 23 and the outer periphery 12 is a nose 25. Note that 26 is a mounting hole.

Next, an end mill using the throw-away tip 11 of this invention will be explained based on FIGS. 4 and 5. In these figures, numeral 31 is a tool body (end mill body) having a tip pocket 32, and the tip pocket 32 has a tip seat 33 formed therein. A protrusion 34 is provided at a predetermined location on the chip seat 33.

The chip 11 has its wall surfaces 19, 23 in contact with the projection 34, and the distance between the tip (cutting start point) 35 of the chip 11 and the rotation center axis 36 (the distance between the rotation center axis 36 and the center of the chip 11). E is a predetermined dimension (preferably about 1/18th of the outer diameter of the chip 11, and the larger the distance E, the better the machinability).
During cutting, the non-cutting part 37 is placed on the chip seat 33 so as not to interfere with the workpiece 38 as shown in FIG. 33 with a positive axial angle.

According to this embodiment, the tip 11 can be attached to the tool body 31 by bringing the wall surfaces 19 and 23 into contact with the protrusion 34 of the tool body (end mill body) 31, so that the tip 11 can be mounted in the circumferential direction. The tip 11 does not turn stably even when a force is applied to turn it, can sufficiently withstand interrupted cutting, has good seating comfort, is easy to operate, and requires a small number of parts.

In addition, since the V-shaped notch 15 is provided on the outer periphery, the length of the cutting edge is shortened, and this notch 15
Since the intersection between one wall surface 19 and the upper surface 3 of the chip 11 is formed into a convex curved surface 22, the cutting load gradually increases as cutting progresses.
Even in interrupted cutting, it does not receive a large impact all at once, so it has good cutting performance and durability, and can prevent chipping and chipping of the cutting edge. In addition, since the convex curved surface 22 is formed, the discharge of cutting chips is greatly improved, and it is possible to prevent deterioration of the cutting surface due to entrainment or collision of chips, and to prevent breakage and chipping of the chip 11. Rotation center shaft 36 and chip 1
The distance E from the center of 1 can be increased, which further improves chip evacuation and cutting performance.

In addition, as shown in FIG. 3B, in the chip 11, one wall surface 19 of the notch 15 is
A diameter line 21 passing through the intersection 20 of and the outer periphery 12
Since the chip 1 is tilted relative to
The cutting edge angle of each cutting edge 16, 17, 18 in a plan view from the direction orthogonal to the upper surface 13 of the blade 1, that is, the tangent line m ₁ at the cutting edge position and the extension line m ₂ of the wall surface 19
The angle θ formed by the two ends is an obtuse angle, and the strength of the cutting edge is high.

Moreover, since one wall surface 19 of the notch 15 is inclined with respect to the diameter line 21, the convex curved surface 22 is also inclined from the diameter line 21 along the wall surface 19. Therefore, as shown in _FIG . Top surface 1 toward the inner circumference
It gradually protrudes toward the chip upper surface 13 side from the parallel line H ₂ with 3. Therefore, the cutting edge 16,1
The cutting edge angle θ in a cross-sectional view orthogonal to the upper surface 13 of the cutting edges 16, 17, 18 is larger in the portion extending along the convex curved surface 22 than in the portion extending along the upper surface 13 of these cutting edges 16, 17, 18, which particularly prevents chipping. The strength of the edge of the cutting edge, where this is likely to occur, has been further increased.

[Effect of idea]

As explained above, according to the present invention, in a circular plate-shaped throw-away chip with a circular outer periphery, the tip reaches from the top surface to the bottom surface of the throw-away chip at a position dividing the outer periphery into three equal parts, and ,
A notch is formed that is approximately V-shaped when viewed in plan from a direction perpendicular to the top surface, and one wall surface of this notch extends from the intersection of the one wall surface and the outer circumference toward the inner circumference side in the plan view. The groove is formed into an inclined surface that gradually slopes toward the other wall surface of the notch with respect to a diameter line passing through the intersection of the one wall surface and the outer periphery of the throwaway chip, and one side of the notch The intersection of the wall surface and the top surface is
Since it is formed into a convex curved surface that smoothly continues with the one wall surface and the upper surface when viewed from the side from the outer circumferential side of the throw-away tip, the following effects are achieved.

First, the throw-away tip can be attached to the tool body by bringing both walls of the V-shaped notch into contact with the protrusion provided on the tool body, thereby preventing the throw-away tip from rotating. The seating of the throw-away tip on the tool body is greatly improved, it can withstand interrupted cutting, it improves operability, and it requires fewer parts.

In addition, since the V-shaped notch is provided, the length of the cutting edge is shortened, and since the convex curved surface is formed, the cutting load gradually increases as cutting progresses, and It can prevent large impact forces from being applied all at once, improving machinability and durability, greatly improving chip evacuation, and preventing deterioration of the cut surface due to chip entrainment or contact. ,
As a result, cutting performance can be further improved, and breakage and chipping of the throw-away tip, which were particularly common in the past, can be reliably prevented.

Furthermore, since one wall surface of the notch is made into an inclined surface, the cutting edge angle of each cutting edge when viewed in plan from the top surface of the chip becomes an obtuse angle, increasing the strength of the cutting edge. The angle of the cutting edge in a cross-sectional view perpendicular to the upper surface is increased, and the strength of the cutting edge is further increased.As a result, breakage of the cutting edge, especially at the cutting edge portion, can be more reliably prevented and the life of the chip can be greatly improved.

[Brief explanation of drawings]

Figure 1 is a front view showing one embodiment of the present invention;
The figure is a side view, and Figure 3A is a diagram showing the positional relationship between the throw-away tip and the workpiece during cutting.
Figure B is an enlarged view of the cutting edge of the throw-away tip, Figure C is a sectional view taken along the diameter line 21 of Figure B,
Figure 4 is a front view showing the throw-away tip of the present invention attached to the end mill body, Figure 5 is a side view of Figure 4, and Figure 6 is the conventional throw-away tip attached to the end mill body. 7 is a side view of FIG. 6, FIG. 8 is a front view of a conventional round throw-away tip, and FIG. 9 is a side view of a conventional round throw-away tip. 12...Outer circumference, 13...Top surface, 14...Bottom surface (bottom surface), 15...Notch, 19...One wall surface,
20... Intersection between one wall surface and the outer periphery, 21...
Diameter line, 22... convex curved surface, 23... other wall surface.

Claims (1)

[Claims for Utility Model Registration] In a throw-away chip 11 having a round plate shape with a circular outer periphery 12, from the upper surface 13 to the lower surface 14 of the throw-away chip 11, the outer periphery 12 is divided into three equal parts. A notch 15 is formed which extends to the top and has a substantially V-shape when viewed in plan from a direction perpendicular to the upper surface 13, and one wall surface 19 of this notch 15 is connected to the outer periphery of the other wall surface 19 in the plan view. 12, the other side of the notch 15 is connected to the diameter line 21 passing through the intersection 20 between the one wall surface 19 and the outer periphery 12 of the throwaway chip 11. It is formed into an inclined surface that gradually slopes toward the wall surface 23 side, and is formed on one wall surface 19 of the notch 15 and the upper surface 1.
The intersection with 3 is the throwaway tip 11
1. A throw-away chip characterized in that it is formed into a convex curved surface 22 that smoothly continues with the one wall surface 19 and the upper surface 13 when viewed from the side from the outer periphery 12 side.