JPH042736Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the improvement of a cutting tool such as an end mill that performs cutting by feeding a cutter laterally.

[Prior art] Conventionally, as an end mill,
There is one shown in the figure. The end mill shown in these figures has three cutting tips 2 on the outer periphery of the tip of a tool body 1 that rotates around its axis.
a... are positioned point-symmetrically with each other across the axis,
and are arranged spaced apart from each other in the axial direction, and two cutting blade tips 2b are respectively arranged in the circumferential middle part of these cutting blade tips 2a... spaced apart from each other in the axial direction, Opposing ends of cutting blade tips 2a, 2a adjacent in the direction;
Both ends of the cutting blade tip 2b overlap in their rotation loci, and the cutting blade tips 2a, 2b
...The overall structure allows for flat cutting of the work material. In addition, the code 3 in the figure
are clamp screws for fixing the cutting blade tips 2a, 2b to the tool body.

With such an end mill, it is possible to cut a width much longer than the cutting edge length of a single cutting tip with a single feed.
This method has advantages such as being able to improve the processing efficiency of the cutting process and being able to perform the cutting process at a considerably deep part of the upper surface of the workpiece.

[Problems to be solved by the invention] Generally, when cutting is performed using an end mill, each cutting edge tip repeats cutting and non-cutting every time the cutter rotates once, resulting in an interrupted cutting process. Impact force is applied repeatedly to the chip. For this reason, the impact force is transmitted to the tool body, causing the cutter to vibrate, making the cutting edge of the cutting tip more likely to break. However, in the above-mentioned end mill, since the plurality of cutting tips are spaced apart from each other in the axial direction of the tool body, the length of the part of the tool body where the cutting tips are attached becomes long. ing. For this reason, a large impact force is applied to the tool body during cutting, which tends to cause chatter in the cutter. Therefore, in order to prevent damage to the cutting edge due to cutter chatter, there has been a problem in that cutting conditions must be significantly restricted, such as by limiting the material of the workpiece or reducing the depth of cut.

This idea was made in view of the above circumstances,
It is an object of the present invention to provide a cutting tool that can effectively prevent the cutting edge of a cutting tip from being damaged due to chatter of the cutter, and can therefore perform heavy cutting.

[Means for Solving the Problems] This invention achieves the object, and has at least one end opening in the outer peripheral surface of the tool body, and a direction perpendicular to the axis of the tool body. A hole extending in a direction along the tool body is formed, and a pin made of a metal having a higher elastic modulus than the tool body is integrally fitted into the hole.

[Function] In the cutting tool with the above configuration, a pin made of a metal with a higher elastic modulus than the tool body is fitted into the hole in the tool body, so the cutting tool itself resists torsional deformation. It has high rigidity and excellent damping ability. Therefore, even if the tool body receives a large impact force, it will not easily undergo elastic deformation, and even if chatter occurs, it can be absorbed.

[Example] Hereinafter, an example of this invention will be shown in Figures 1 to 5.
This will be explained with reference to the figures. 1 to 5 are diagrams showing an end mill according to an embodiment.

In FIG. 1, reference numeral 4 indicates a tool body. The tool body 4 has a cylindrical shape, and a plurality of cutting tips 2a, 2b, . There is. This tool body 4 has the same dimensions spaced apart from each other on opposite sides of the axis O, which are mutually shifted in the direction of the axis O, and which are arranged on opposite sides of the axis O.
Two holes (hole portions) 5, 5 extending in a direction perpendicular to
is formed. Further, in the wall portion on the rear end side of these holes 5, 5, holes (hole portions) 6, 6 extending in a direction perpendicular to the axial direction of the holes 5, 5 are formed in the same manner as described above. A pin 7 is fitted into each hole 5, 6, . . . .

The pin 7 is made of cemented carbide and has a diameter slightly larger than the inner diameter of the holes 5 and 6. Note that the pin 7 is fitted into the holes 5 and 6 by shrink fitting.

Such an end mill has holes 5 in the tool body 4,
Since the pins 6 made of cemented carbide are fitted in the pins 6, the pins 6 have high rigidity against torsional deformation and have excellent damping ability. Moreover, since the diameter of the pin 7 is slightly larger than the inner diameter of the holes 5 and 6, the inner circumferential surfaces of the holes 5 and 6 are pressed by the outer circumferential surface of the pin 7. Compressive and tensile forces are applied to the wall around the pin 7. Therefore, internal stress that resists the compressive force and the tensile force is generated inside the tool body 4, and the tool body 4 has high rigidity and excellent damping ability.

Therefore, in the above-mentioned end mill, not only does the tool body 4 not easily undergo elastic deformation even when subjected to a large impact force, but even if chatter occurs, it can be absorbed, making it suitable for heavy cutting. The end mill does not shake even when the cutting edge is cut with 2 tips.
Breakage of the cutting edges a, 2b, . . . can be effectively prevented.

In the above embodiment, the pin 7 is made of cemented carbide, but if it is made of ultra-hard sintered alloy such as CBN or tungsten-based sintered metal (so-called heavy alloy), the pin 7 can be used as an end mill. Its own rigidity and damping capacity can be further increased. Further, although the diameter of the pin 7 is larger than the inner diameter of the holes 5 and 6, a pin having a smaller diameter than the inner diameter is fitted inside the holes 5 and 6, and the two are joined by brazing. Good too. Furthermore, the present invention is not limited to end mills as in the above embodiments, but can be applied to milling cutters, boring bars, drills, etc. to obtain the same effects as in the above embodiments.

[Effects of the invention] As explained above, the cutting tool of this invention has the following effects:
A hole portion is formed in the tool body, and at least one end thereof is open to the outer circumferential surface of the tool body and extends in a direction perpendicular to the axis of the tool body. Since the cutting tool itself has a structure in which a pin made of a metal with high hardness is integrally fitted, the cutting tool itself has high rigidity against torsional deformation and also has excellent damping ability.
Therefore, even if the tool body receives a large impact force, it will not easily become elastically deformed, and even if chatter occurs, it can be absorbed, so the cutting tool will not vibrate even during heavy cutting. , it is possible to effectively prevent the cutting edge of the cutting edge from being damaged.

[Brief explanation of the drawing]

1 to 5 are views showing one embodiment of the present invention, in which FIG. 1 is a side view showing an end mill;
Fig. 2 is a view taken in the direction of Fig. 1, Fig. 3 is a view taken in the direction of Fig. 1, Fig. 4 is a sectional view taken along the - line in Fig. 1, and Fig. 5 is a - line view in Fig. 2. Sectional view, 6th
8 to 8 are views showing an example of a conventional cutting tool, in which FIG. 6 is a side view showing an end mill, FIG. 7 is a view taken in the direction of the arrow in FIG. 6, and FIG. FIG. 1... Tool body, 2a... Cutting tip, 2b...
...cutting blade tip, 4...tool body, 5...hole (hole), 6...hole (hole), 7...pin.

Claims (1)

[Scope of utility model registration request] A cutting tool in which a cutting tip is attached to the outer periphery of the tip of a tool body that is rotated around an axis, wherein at least one end is opened in the outer circumferential surface of the tool body and perpendicular to the axis. Forming a hole extending in the direction along the direction,
A cutting tool characterized in that a pin made of a metal having a higher elastic modulus than the tool body is integrally fitted into the hole.