JPH031138Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a throw-away tip suitable for use in a throw-away ball end mill.

[Prior Art] Figs. 21 and 22 show a conventional throw-away tip (hereinafter abbreviated as a tip) used in a single-blade throw-away ball end mill.

This chip 1 is plate-shaped with a lower surface 2 serving as a seating surface, and a ridgeline portion of the upper surface 3 serving as a rake surface, which is located on the outer peripheral side of the tool body 4 of the ball end mill, has a substantially arc-shaped part. An outer circumferential cutter 5 having a convex curve is formed. Further, a linear bottom side 6 is formed on the ridgeline portion of the upper surface 3 of the peripheral cutter 5 located on the tip end side of the tool body 4. As shown in FIG. 22, this chip 1 is
It is attached to the tool body 4 with its bottom blade 6 spaced apart from the axis O of the tool body 4.

By the way, when attempting to perform axial cutting with the ball end mill equipped with the conventional tip 1, since the bottom blade 6 is separated from the axis O of the tool body 4, there is an uncut portion of the workpiece at the center of rotation. A cylindrical core is formed, and this core hits the chip 1 itself. Therefore, this chip 1
In some cases, there was a disadvantage that axial cutting could not be performed.

For this reason, a tip 8, as shown in FIGS. 23 and 24, has been proposed in which a bottom cutting edge 7 is formed so as to cross the axis O of the tool body 4. According to this chip 8, no core is formed at the center of rotation of the tool body 4, and therefore both lateral cutting and axial cutting can be performed.

[Problems to be solved by the invention] However, in the conventional chip 8 shown in FIGS. 23 and 24, the bottom blade 7 is
The cutting speed of the part located near the axis O of the tool body 4 is extremely low, and when cutting in the axial direction, a large thrust load acts on this part. There was a problem that the portion near O was easily damaged. In addition, since the bottom blade 7 is formed so as to cross the axis O of the tool body 4 to which it is attached, as the diameter of the tool body 4 increases, the dimensions of the tip 8 must also increase. There was a problem that it was uneconomical due to the soaring prices.

[Purpose of the invention] This invention was made in view of the above circumstances.
The purpose of the present invention is to provide an economical chip that can perform both lateral cutting and axial cutting with just one chip, and does not cause an increase in size even when the diameter of the tool body increases. It is something.

[Means for solving the problem] The tip of this invention has a lower surface as a seating surface and an upper surface as a rake surface, and is mounted on a tip mounting seat on the outer periphery of the tip of a tool body that rotates around an axis.
In a throw-away tip in which cutting edges are formed on the outer and inner circumferential sides of the tool body on the upper surface so that cutting is performed simultaneously with the outer and inner edges, the tip mounting seat of the tool body is on the lower surface. A contact surface is formed that engages with the contact surface formed on the chip and receives a component force applied to the chip in a direction parallel to the seating surface during cutting.

[Example] Figures 1 to 7 show a first example of the chip of this invention, and the same components as those of the conventional chip shown in Figures 21 to 24 are given the same reference numerals. The explanation will be omitted.

1 to 4, this chip 10 has an inner circumferential cutting edge 11 formed on the ridgeline portion of the upper surface 3 located on the inner circumferential side when mounted on the tool body. Further, a groove portion 12 having a U-shaped cross section is formed in the center of the lower surface 2 of the tip 10 along the axial direction of the tool body. The side surface of this groove portion 12 facing the inner peripheral blade 11 side is
It serves as an abutment surface 13 for receiving the feed force of cutting by the outer peripheral blade 5 during cutting. Further, the side surface of the groove portion 12 facing the contact surface 13 serves as a contact surface 14 for receiving the feed force of the cutting by the inner circumferential cutter 11 during cutting.

As shown in FIGS. 5 to 7, this chip 10 is constructed by positioning its outer circumferential cutter 5 and inner circumferential cutter 11 on the outer circumferential side and inner circumferential side of the tool body 4 of the ball end mill, respectively. It is detachably mounted on a chip mounting seat on the outer periphery of the tool body 4, which is spaced apart from the axis O of the tool body 4. Here, the chip 10 is fixed by engaging a groove 12 formed on its lower surface 2 with a convex part 15 formed on the chip mounting seat. On the other hand, a core storage recess 16 having a predetermined depth is bored in the center of the tip of the tool main body 4 along the direction of the axis O from the tip surface. This core storage recess 16 is used to hold the chip 10 during cutting.
This is to accommodate a cylindrical core that is created in the material to be cut due to the separation of the core from the axis O.
The tip 10 is mounted with its inner circumferential blade 11 exposed in the core storage recess 16 of the tool body 4.

When cutting in the axial direction with a ball end mill equipped with such a tip 10, the tip 1
An annular groove is cut into the material to be cut by the bottom blade 6 of 0. As a result, a core having a radius equal to the distance from the axis O to the inner peripheral end of the bottom blade 6 of the chip 10 is generated in the workpiece located at the center of rotation of the tool body 4. This core grows relatively as the ball end mill feeds and is stored in the core storage recess 16, and is then scraped off by the inner circumferential blade 11 of this chip 10 when performing cross cutting. go. In addition, when performing simple traverse cutting, cutting is performed by the outer circumferential cutter 5 of this chip 10.

However, when it comes to the tip 10 attached to such a throw-away ball end mill,
Inner peripheral blade 1 facing into core storage recess 16 of tool body 4
1, it is possible to perform both lateral cutting and axial cutting as described above. Moreover, by forming the inner circumferential cutter 11, it can be mounted on the outer circumference of the tool body 4 at a distance from the axis O thereof, so that the cutting speed at the inner circumferential end of the bottom cutter 6 becomes faster. An excessive thrust load is no longer applied to the inner circumferential end of the bottom blade 6, thereby preventing the bottom blade 6 from being damaged. Also, if the diameter of the ball end mill to be installed is large,
It can be used by being attached to the outer circumferential side of the tool body 4 as it is without increasing its dimensions.

Furthermore, in the case of this chip 10, a groove 12 is formed in the center of the lower surface 2, so that the contact surface 13 with the tool body 4 receives the feeding force of cutting by the outer peripheral cutter 5 and the inner peripheral cutter 11, respectively. , 14 are formed independently, even when cutting with a large cutting load, there is no deviation or rattling, and highly accurate cutting can be performed.

[Other Embodiments] FIGS. 8 to 11 show a second example of the chip of this invention. In the chip 20 of this example, two sets of the above-mentioned peripheral blades 5a, 5b bottom blades 6a, 6b and inner circumferential blades 11a, 11b are each formed to be rotationally symmetrical by 180 degrees. That is, in this chip 20, when one of the outer circumferential cutter 5a, bottom cutter 6a and inner circumferential cutter 11a is worn out due to cutting, the other outer circumferential cutter 5b, bottom cutter 6b and The inner peripheral cutter 11b can be used. Also, in this chip 20,
A groove 12 similar to that shown in the first example is formed in the center of the lower surface 2.

Moreover, FIGS. 12 to 19 show a third example of this invention.

12 to 16, the chip 25 of this example has, in addition to that of the second example shown in FIGS. 8 to 11, the upper surface 3 of the chip 25.
Each corner portion 26a, 26b between the bottom blade 6a, 6b and the inner peripheral blade 11a, 11b is connected to the top surface 3, respectively.
It is formed by an inclined surface in which the thickness between the upper and lower surfaces 2 and 3 gradually decreases from the center toward the respective corners 26a and 26b. And this chip 2
5, as shown in FIGS. 17 to 19, by positioning the tip of the upper surface 3 on the tip mounting seat of the tool body 4 above the axis O of the tool body 4, radial It is mounted and used with a negative rake angle.

Therefore, with the chips 20 and 25 of the second and third examples, in addition to being able to obtain the same effects as those shown in the first example, two sets of peripheral blades are also provided. 5a, 5b, bottom blade 6
a, 6b and the inner circumferential cutters 11a, 11b are formed in a 180° symmetrical shape, so when one of the outer circumferential cutters 5a etc. is worn out, by rotating it 180°, the above outer circumferential cutters 5a etc. Since it is possible to use the outer circumferential cutter 5b, etc., which are opposed to the outer circumferential cutter 5b, it is excellent in economical efficiency.

In addition, especially in the case of the tip 25 shown in the third example above, as shown in FIGS. Even when the radial rake angle at the peripheral edge 5a is negative, the 20th
As shown in the figure, since the corner portion 26a near the tip 27 of the inner circumferential cutter 11a is formed by an inclined surface, the radial rake angle at the tip 27 of the inner circumferential cutter 11a is indicated by the two-dot chain line in the figure. It does not increase in the positive direction and cause a second hit on the flank, unlike the conventional one shown in . Therefore, as shown in FIG. 18, a large amount of back metal H can be secured in the tool body 4, thereby increasing the tool rigidity of the tool body 4 to be mounted.

In addition, in all the above embodiments, the groove portion 12 is formed on the lower surface 2 of the chips 10, 20, 25,
Although contact surfaces 13 and 14 are formed on the side surfaces of this groove 12 to receive the feeding force due to cutting by the outer circumferential cutter 5 and the inner circumferential cutter 11, the present invention is not limited to this. The abutting surfaces may be formed on each side surface of the protrusion, and a groove in which the protrusion engages may be formed on the tool body 4 side.

[Effects of the invention] As explained above, in this invention, the lower surface is the seating surface and the upper surface is the rake surface. In a throw-away tip in which cutting edges are formed on the outer circumferential side and the inner circumferential side of the tool body on the upper surface so that the outer circumferential edge and the inner circumferential edge cut simultaneously, a tip mounting seat of the tool body is provided on the lower surface. A contact surface is formed that engages with the formed contact surface and receives a component of force applied to the chip in a direction parallel to the seating surface during cutting. Therefore, when the inner peripheral cutter is attached to a tool with a distance from the axis and both the outer peripheral cutter and inner peripheral cutter are used for cutting at the same time, the force applied to the chip in the radial direction of the tool body is applied to the tool. The chip can be received by the tool body through the surface, and even when machining with a large cutting load, there is no misalignment or play in the chip installation, and highly accurate cutting can be performed.

[Brief explanation of drawings]

Figures 1 to 4 show the first embodiment of the throw-away tip of this invention. Figure 1 is a front view, Figure 2 is a side view, and Figure 3 is A ₁ - A of Figure 1. ₁
The line view, Figure 4 is the A ₂ -A ₂ line view of Figure 3, Figure 5
The figure is a front view showing the state in which the tip is attached to the tool body, Figure 6 is a side view of the same, and Figure 7 is the same as Figure 6.
A ₃ - _{A 3} line view and Figures 8 to 11 show the second embodiment of this invention, Figure 8 is a front view, and Figure 9 is a front view.
The figure is a side view, Figure 10 is a view from line A ₄ - A ₄ of Figure 8,
Fig. 11 is a view taken along line _A5 - _A5 in Fig. 10, Figs. 12 to 16 show a third embodiment of this invention, Fig. 12 is a front view, and Fig. 13 is a side view. , 1st
Figure 4 is a view from line A ₆ - A ₆ in Figure 12, Figure 15 is a view from line A ₇ - A ₇ in Figure 12, and Figure 16 is a view from line A 7 - A 7 in Figure 14.
A ₈ - _{A 8} line view, Fig. 17 is a front view showing the above chip attached to the tool body, Fig. 18 is a side view of the same, and Fig. 19 is a view from A ₉ - A ₉ line of Fig. 18. Figure 20 is a schematic diagram showing the position of the tip of the inner peripheral blade of the tip, Figures 21 and 22 show a conventional throw-away tip, and Figure 21 shows the tip installed in the tool body. The front view shown in Fig. 22 is the second
A ₁₀ - A ₁₀ line view of Figure 1, Figures 23 and 24
The drawings show another conventional tip, in which Fig. 23 is a front view showing a state in which it is attached to a tool body, and Fig. 24 is a view taken along line A ₁₁ -A ₁₁ in Fig. 23. 10, 20, 25... Throwaway tip,
2...Bottom surface, 3...Top surface, 4...Tool body, 5,
5a, 5b...Outer peripheral blade, 6, 6a, 6b...Bottom blade, 11, 11a, 11b...Inner peripheral blade, 12...
Grooves, 13, 14...Abutment surfaces, 26a, 26b...
...Slope.

Claims (1)

[Claims for Utility Model Registration] (1) The lower surface is a seating surface and the upper surface is a rake surface, and the tool body is mounted on a tip mounting seat on the outer periphery of the tip of a tool body that rotates around an axis, and the tool body on the upper surface In the indexable tip, cutting edges are formed on the outer circumferential side and the inner circumferential side, respectively, so that the outer circumferential edge and the inner circumferential edge cut simultaneously. A throw-away tip characterized by being formed with an abutment surface that engages with the contact surface and receives a component of force applied to the tip in a direction parallel to the seating surface during cutting. (2) The upper surface has a corner portion sandwiched between the outer peripheral cutter and the inner peripheral cutter formed by an inclined surface in which the thickness between the upper and lower surfaces gradually decreases from the center of the upper surface toward the corner portion. 2. The throw-away tip according to claim 1, wherein the throw-away tip is formed as a polygon.