JP3792741B2 - Throw-away cutter - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a throw-away cutter used in a milling machine operation.
[0002]
[Prior art]
As the throw-away tip of the throw-away type cutter, those using a triangle or a tetragon are generally put into practical use. In a cutter using a triangle / quadrature throw-away tip, the outer peripheral side of the throw-away tip also has a balance with the amount of cutting in the axial direction. In general, no constraining surface is provided. Examples of hexagonal and octagonal tips are used in roughing end mills and the like. The (Kokoku 3-75285 discloses as an example), take a lot of number of angles is shorter the length of one side, to shorten the insert cutting edge length in the case of acting as a cutting edge to edge itself, cutting This type of end mill is effective in maintaining rigidity because the resistance is dispersed and the tool diameter is small.
[0003]
[Problems to be solved by the invention]
In order to more firmly fix the throw-away tip, especially during high-speed cutting, the tip receives a force in a direction to penetrate to the outer peripheral side due to centrifugal force accompanying rotation, radial component force accompanying cutting, etc. It is necessary to provide a stopper. Further, in order to further reduce the radial component force during cutting, it is necessary to shorten the cutting edge length and reduce the cutting resistance applied to one chip.
[0004]
[Means for solving problems]
Therefore, in the present invention, in the throw-away type cutter in which a large number of throwaway tips are detachably fixed in the tip seat of the outer periphery of the tool body tip, and both the radial rake angle and the axial rake angle are negative angles, the throw-away tip has a number of angles of substantially regular hexagon or higher, the contact surface when the fixed chip seat, so the two sides of the outer peripheral portion of the axial and radial directions, said axial those contact surface 6 is substantially disposed in parallel with the perpendicular of the tool axis of rotation, using an eccentric screw in the fixing of the chip, that has been fixed so as to contact the abutment surface 7 of the outer peripheral portion of the radial The throwaway cutter is characterized by a tool body made of ductile cast iron.
[0005]
[Action]
First, in order to ensure the strength and rigidity of the chip holding portion, it is necessary to form the bottom surface of the chip seat so as to hold the chip at a position where the rake angle in the axial direction / radial direction is 0 degree to negative. Further, when fixed to the chip seat, the substantial restraint surface is arranged so that the axial direction of the chip is the upper part and the radial direction is the outer peripheral part, and in particular, is in contact with the centrifugal force direction. For this reason, the cutting amount is restricted, but by setting the throw-away tip to a hexagon or more, adjacent outer peripheral cutting edges can act as cutting edges for the length.
Next, an eccentric screw is used to fix the chip, and the tip is fixed so as to abut on the outer peripheral portion in the radial direction . In addition, structural steel is sufficient for the tool body, but if it is made of ductile cast iron, it has a vibration-proofing effect against vibration, chatter, etc., and can be selected according to the work material, the purpose of cutting, and the like.
Hereinafter, it demonstrates in detail based on an Example.
[0006]
【Example】
1 and 2 show examples of a throw-away cutter and a chip according to an embodiment of the present invention. The throw-away cutter has a throw-away tip 3 fixed at three locations on the outer periphery of the shank portion 1 and the tool body 2 by eccentric screws 4. The throw-away tip 3 has a substantially regular hexagonal shape, the side 5 of the tip is a cutting edge , the side 6 of the tip is an axial direction, and the side 7 of the tip is a constraining surface for loosening in the radial direction. The direction rake angle is set to -4 degrees and the radial direction rake angle is set to -3 degrees.
In this example, since the tool body is made of ductile cast iron, it has a rounded shape suitable for casting, but in order to maintain more rigidity, it is a material that combines steel, cemented carbide, etc. You may form by.
[0007]
Next, an approximately regular octagonal throw-away tip is shown in FIGS. When a regular octagonal tip is used, it is more advantageous than a regular hexagon. In the regular octagon, as can be seen from FIG. 3, the surface that is in contact with the outer periphery is parallel to the axial direction and is the optimum angle for contact with centrifugal force.
[0008]
【The invention's effect】
As described above, according to the present invention, when the throw-away tip is fixed to the tip seat, the substantial restraint surface is set at two locations on the outer peripheral portion in the axial direction and the radial direction, so that the tip is securely fixed. Can be done.
[Brief description of the drawings]
FIG. 1 shows an example of a throw-away cutter according to the present invention.
FIG. 2 shows a throw-away tip used in FIG.
FIG. 3 shows another embodiment of the present invention.
FIG. 4 shows the throw-away tip used in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shank part 2 Tool body 3 Throw away tip 4 Eccentric screw 5 Tip edge ( cutting edge )
6 Tip side (Axial contact surface)
7 Tip side (radial contact surface)

Claims (3)

In a throw-away cutter in which a large number of throw-away tips are detachably fixed in a tip seat at the outer periphery of the tool body tip, and the rake angle in the radial direction and the rake angle in the axial direction are both negative angles, the throw-away tip is approximately has a number of angles of the regular hexagon or higher, the contact surface when the fixed chip seat, so the two sides of the outer peripheral portion of the axial and radial contact surface 6 of the shaft direction, the tool substantially arranged parallel to the perpendicular line of the rotation center line, using eccentric screw to fix the said tip, indexable, characterized in that the fixed so as to contact the abutment surface 7 of the outer peripheral portion of the radial Cutter.   2. The throw-away cutter according to claim 1, wherein the tool body is made of ductile cast iron.   The throwaway cutter according to claim 1 or 2, wherein the throwaway tip is formed of a substantially regular octagon.

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