JPS6059084B2 - Throwaway tip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a throw-away tip that is removably attached to, for example, a tool holder.

In general, indexable tips, which form the cutting edge of cutting tools, have a lower cost per cutting edge than resharpened brazed tips, and it requires less effort to replace worn tips with new ones. , the positional relationship between the tool holder and tip after replacement is reproducible.
Widely used in industry. However, this throw-away chip has the disadvantage that it is very expensive because it is made of expensive materials such as tungsten and cobalt. FIG. 1a is a perspective view of such a conventional throw-away tip in relation to a cutting tool holder.

As shown in FIG. 1a, the throw-away tip 1 has a mounting hole 5 into which a tip fixing pin 4 attached to the shim 3 of the cutting tool holder 2 is fitted. When the tip 1 is to be attached to the tool holder 2, the tip fixing pin 4 is inserted into the attachment hole 5, the tip 1 is placed on the shim 3, and the tightening screw 6 is tightened. Then, the fixing pin 4 is tilted toward the side wall surface 7 of the chip seat, and the chip 1 is tilted toward the side wall surface 7 of the chip seat.
It is pressed into place and fixed. In this way, the tool holder 2
Cutting is carried out by bringing the throw-away tip 1 attached to the workpiece into contact with the workpiece. In normal cutting, the flank surface 1a and rake surface forming the cutting edge of the tip 1, as shown in FIG. lb, flank wear Ba and rake face wear 8b occur. In particular, the width VB of flank wear Ba, which is directly related to the dimensional accuracy of the workpiece and the roughness of the top surface.
is narrow, usually less than O,5Tfrfn, and a relatively small amount of cutting edge wear occurs in a very limited portion of the tip 1. Furthermore, in terms of cutting theory, for example, as shown in FIG.
can be decomposed into principal force P, feed force P2, and backward force Pa, and the ratio of their magnitudes is determined by the material of the workpiece 9 and the tip 1.
10 depending on the shape of the tool holder 2, cutting conditions, etc.
0:35:2 You can think of it as the second day of the week.

From this, it can be seen that the tip・1 in the direction in which the feed component force P2 acts
It can be seen that the dimension, ie, the width, is not as necessary as the dimension, ie, the thickness, of the chip 1 in the direction in which the principal force P acts. However, in the conventional tip 1, the width is usually larger than the thickness of the tip 1 due to the fixing mechanism to the tool holder 2, compatibility, etc. For example, in the conventional round piece throwaway tip 10 shown in FIGS. 3A and 3B,
Diameter of the tip 10 A1 Diameter of the mounting hole 11 into which the tip fixing pin provided on the tool holder is inserted D1 Tip 1
The relationship between the thickness T10 and the width E of the chip 10 is usually the first
The values are as shown in the table.

In the above-mentioned round piece-shaped chip 10, the diameter A of the chip 10 is approximately 25 times the diameter d of the mounting hole 11, as shown in Table 1.

As described above, there has been no conventional throw-away chip in which the volume of the chip is actively reduced as much as possible in order to rationally save resources, taking into account wear patterns and cutting resistance. This invention was made based on the above-mentioned circumstances, and takes into consideration the location where wear occurs, its degree, the magnitude of cutting resistance, and the direction in which it acts.This invention is an inexpensive and effective method that does not reduce strength or cutting performance. Provides a throw-away tip that is compatible with conventional tips. The porpose is to do.

Hereinafter, an embodiment of the present invention will be explained as shown in FIGS. 4 and 5.
This will be explained with reference to the figures.

Figure 4 is an exploded perspective view showing the throw-away tip of this embodiment in relation to the tool holder. and the fifth
The figure is a plan view of the throw-away tip of this embodiment.

In FIGS. 4 and 5, 12 is a triangular throw-away chip made of a material such as tungsten or cobalt.

The thrower way tip 12 has a cylindrical shape having a triangular cavity 13 having a shape similar to or similar to the shape of its outer periphery and having the same distance from each corresponding side. Reference numeral 14 denotes an insert body to be inserted into the cavity 13 of the throwaway tip 12, and the ring part has a shape similar to or similar to the shape of the cavity 13.

This insert 14 has a mounting hole 15 into which a tip fixing pin 4 attached to the shim 3 of the tool holder 2 is inserted. In addition, in order to securely and easily fix the tip 12 to the tool holder 2, and to improve the machinability and workability of the tip 12, the cavity 13 of the tip 12 and the insert body 1 are
The mounting holes 15, chip fixing pins 4, etc. are chamfered at necessary locations. When attaching the throw-away tip 12 having such a configuration to the tool holder 2, first fit the insert 14 into the cavity 13 of the tip 12 to integrate the two, and then fit the insert 14 into the mounting hole 15 of the insert 14 for fixing the tip. Insert pin 4.

In this state, when the tightening screw 6 is tightened, the fixing pin 4 tilts toward the chip seat side wall surface 7, and the insert 14
The chip 12 into which the insert body 14 is fitted is pressed against the chip seat side wall surface 7 and fixed. As described above, according to this embodiment, the wear pattern of the tip and the cutting resistance P.

After taking into consideration, the hollow part 1 has a shape similar to or similar to the shape of the outer periphery and the distance from each corresponding side is equal.
3, the size of the cavity 13 is much larger than the conventional mounting hole 5, and the tip 12 can be formed using less material than before without degrading strength or cutting performance. can be produced. Therefore, the amount of expensive tungsten and cobalt used is reduced,
It will be cheaper than before. Further, an insert body 14 is formed, the ring portion of which has a similar or similar shape to the shape of the cavity 13 of the throw-away chip 12 and a mounting hole 15 into which the chip fixing pin 4 is inserted. Insert 1
4 can be fitted to fix them to the tool holder 2, so the following effects can be obtained.

(a) By using the insert 14, it can be attached to a conventional tool holder 2 and is compatible with conventional tips.

(b) Since the insert 14 does not wear out due to direct involvement in the cutting action, inexpensive materials can be used and it can be used repeatedly.

Next, another embodiment of the present invention will be described with reference to FIGS. 6A and 6B.

FIGS. 6a and 6b are a plan view and a side view of a circular piece-shaped throw-away tip.

The circular piece-shaped throw-away tip 16 of this embodiment has a cylindrical shape with a cavity 17 concentric with the outer shape, and the diameter of the tip 16 is set at the center of the A1 cavity 17. When the diameter is D,
The diameter D is defined so that A/D is 2 or less (A/D × 2).

An example of the dimensions of such a chip is shown in Table 2. In addition,
In Table 2, T is the thickness of the chip and E is the width of the chip.

The fact that A/D is defined as 2.0 or less in this embodiment means that when the outer diameter of the round piece chip 16 is the same as the conventional one, the diameter of the cavity 17 is the same as the diameter of the conventional mounting hole 11! This means that the size has also increased by about 20% or more.

This is the wear condition of the tip 16 and the cutting resistance P. This shape is designed to actively reduce the volume of the chip in order to save resources, taking into consideration the size and orientation of the chip. When fixing the above-mentioned circular piece-shaped throw-away tip 16 to a tool holder, it can also be fixed using an insert that fits into the cavity 17 of the tip 16, as in the embodiment described above. As shown in FIG. 7, there is a flange 20 for holding the tip 16 against the shim 19 of the tool holder 18, and a flange 20 for holding the tip 16 against the shim 19 of the tool holder 18. An insert 22 having a breaker 21 may be fitted into the cavity 17, and a screw 23 may be inserted into the insert 22 and the shim 19 to fix it. Alternatively, as shown in FIG. 8, the tip 16 is placed on a shim 26 fixed to the tool holder 24 with a screw 25 without using an insert, and the tip breaker 2
7 is attached with a screw 28, the optimum chip breaker width is determined by arbitrarily selecting the position of the serration 30, and the presser fitting 29 is attached to the tool holder 24 with the screw 31, and the tip 16 is fixed. Good too.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and for example, the following modifications are possible.

(a) Chips 32a to 32d as shown in FIG. 9 a to d.
The shape may be a rhombus, a parallelogram, a boat, an ellipse, etc. In addition, the cavities 33 of these chips 32a to 32d
The inserts 34a to 34d that fit into the inserts a to 33d do not need to have attachment holes that fit into the chip fixing pins as shown in the figure. (b) The distance from the cavity to the outer shape, that is, the width of the chip, may be any width that allows a chip breaker to be provided on its surface, and in normal cases, it may be less than the thickness of the chip. The reason for this is that, as shown in FIGS. 1A and 1B, the area where rake face wear 8b occurs is usually a few minutes from the main cutting edge ridgeline of the insert. This is because it is smaller than the chip breaker. Moreover, the cutting resistance P explained in FIG. From the magnitude of each component force and the direction of action, the thickness in the width direction of the chip on which the feed component force P2 acts is:
It can be seen that the thickness may be smaller than the thickness of the chip in the direction in which the principal force P1 acts. (C) The chip fixing pin itself may have a similar or similar shape to the cavity of the chip, and may also serve as an insert.

(d) Although the above embodiments have been explained using throw-away tips for turning as an example, the present invention can also be applied to throw-away tips used for cutting tools of all types and shapes, such as for milling, polling, and drilling. Throwaway tips and inserts can be applied. It goes without saying that various other modifications can be made without departing from the gist of the invention.

As explained above, according to the present invention, the wear area,
Taking into consideration the magnitude of the cutting force and the direction in which it acts, we formed it into a cylindrical shape whose inner shape is similar to or similar to the outer shape, so it can be used without reducing strength or cutting performance - inexpensively and compared to conventional We can provide throw-away tips that are compatible with the tip.

[Brief explanation of drawings]

Fig. 1a is a perspective view showing a conventional throw-away tip in relation to a tool holder and shows the wear condition of the tip, Fig. 1b is a partial sectional view showing the wear condition of the tip, and Fig. 2 is a cylindrical tip. A perspective view showing the direction and magnitude of cutting resistance when three-dimensionally cutting the outer circumference of a shaped workpiece, Figures 3A and b
4 is a plan view and a side view showing a conventional round piece tip, FIG. 4 is an exploded perspective view showing a throw-away tip in an embodiment of the present invention in relation to a tool holder, and FIG. 5 is an embodiment of the present invention. FIGS. 6A and 6B are plan views of the throw-away tip and insert body in the example, and FIGS.
The figure is a cross-sectional view showing an example of how the tip is attached to the tool holder in the embodiment of the present invention, and FIGS. 9A to 9D are plan views showing modified examples of the throw-away tip and the insert body in the present invention. 2...Bite holder, 4...Tip fixing pin, 12...Triangular throw-away tip, 13...Cavity part, 14... - Insert body, 15... Mounting hole, 16... Round piece-shaped throw-away tip, 17... Hollow part.

Claims (1)

[Claims] 1. In an indexable tip that is removably attached to the tip attachment part of a cutting tool, a cavity with a profile similar to or similar to the profile of the tip is provided in the center of the tip, and a cavity with a profile similar to or similar to the profile of this cavity is provided. 1. A throw-away tip, characterized in that an insert having a contoured shape and made of a material different from the tip material is inserted into the cavity and detachably attached to a tip attachment part of a cutting tool.