JPH1128704A - Milling cutter with land on cutting edge - Google Patents

Abstract

(57) [Summary] [Purpose] The cutting edge made of a high-hardness sintered material has a land formed in a short time without harmful chipping,
Provided is a milling machine that can be attached to a main shaft of a processing machine without impairing the peripheral runout accuracy. [Constitution] The center of the inner circumference circle of the main shaft hole 11 of the milling machine 10,
The land is formed with high precision by bringing the cutting edge 12 into contact with the electrode 22 of the electric discharge machine while rotating the milling machine around the axis of the work axis 21 so as to coincide with the center of the work axis 21 of the electric discharge machine. In use, the accuracy of the run-out of the outer periphery of the milling cutter can be maintained at a high accuracy within 0.01 mm. Therefore, in milling, even if the feeding speed is increased, the knife mark does not stand out,
The processing efficiency can be improved without lowering the processing quality. In addition, although a high hardness sintered body is used as a cutting blade material, since the lands are formed by using electric discharge machining, processing can be performed in a short time without generating harmful chips. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a milling cutter having a cutting edge made of a high-hardness sintered body used for wood processing, processing similar to wood processing, metal processing, and the like, and a land formed on the cutting edge.

[0002]

2. Description of the Related Art For example, when processing wood using a woodworking machine, it was possible to improve the processing efficiency by increasing the material feeding speed. As shown in FIG. 10, the pitch P of the knife marks 2 on the surface of the workpiece 1 becomes large, so that the knife marks 2 themselves become conspicuous, and the commercial value of the workpiece 1 is reduced. This pitch P is, when the feeding speed is constant, the number of rotations N of the milling cutter and the number of teeth Z.
Affected by That is, the pitch P decreases as the rotation speed N increases, but there is a limit to the increase in the rotation speed N due to factors such as the rigidity of the milling cutter. Also, the pitch P becomes smaller as the number of blades Z increases, but the increase in the number of blades is limited because the cutting radius of each blade must match with high accuracy in order to increase the number of blades. is there.

On the other hand, conventionally, a milling machine is mounted on a main shaft of a machine using a milling machine, for example, a woodworking machine, and the grindstone is brought into contact with the cutting edge of the cutting blade 12 while rotating the milling cutter 10, thereby cutting the cutting edge. As shown in FIG. 1, a land 13 (width w = about 0.05 to 1 mm) formed of an arc-shaped surface centered on the rotation axis of the milling cutter is formed on the cutting edge so that the cutting radius of each cutting blade can be increased. Milling cutters that match the accuracy are known. Either a rotating circular stone or a non-rotating block stone is used as the grindstone. By forming a land on the cutting edge using the above method, the outer peripheral runout of the milling cutter (radial error of each cutting edge)
Δr can be suppressed within 0.01 mm.

When the milling cutter is used continuously for machining without being detached from the main spindle even after the above-mentioned land is formed, a high accuracy of the peripheral runout Δr is guaranteed, but the milling cutter is mounted on the main spindle. When the state is released, the accuracy of the run-out of the outer periphery of the milling cutter cannot be guaranteed when the tool is mounted on the spindle again.

On the other hand, in recent years, a high-hardness sintered body such as a diamond sintered body or a boron nitride sintered body has been widely used as a cutting blade material for a milling cutter. When a land is formed on the cutting edge, a diamond grindstone whose abrasive grains are diamond is used as a grindstone. However, since the cutting edge material has a high hardness, even if a diamond grindstone is used, it takes a long time to machine the cutting edge to form a land, and furthermore, the cutting edge material is brittle due to its high hardness. For this reason, there is also a problem that harmful chipping often occurs at the cutting edge by forming the land.

The present invention is intended to solve the above-mentioned problem, and has a land formed without harmful chips and in a short time on the cutting edge of a cutting blade using a high-hardness sintered material,
An object of the present invention is to provide a milling machine that can be mounted on a main shaft of a processing machine without impairing the run-out accuracy.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, a structural feature of the invention according to the first aspect is a milling cutter having a land on a cutting edge of a cutting blade made of a high hardness sintered body. In the above, the milling cutter is mounted on the work axis of the electric discharge machine in a state where the axis of the main spindle hole of the milling machine and the axis of the work axis coincide with each other. Is brought into contact with the electrode of the electric discharge machine, so that the land is formed on the cutting edge in an arc shape centering on the axis of the milling cutter.

According to the first aspect of the present invention, the land is formed with high precision by bringing the electrode of the electric discharge machine into contact with the cutting edge while rotating the milling mill about its axis. Therefore, it is possible to maintain the accuracy of the peripheral runout of the milling cutter with high accuracy. In addition, when forming a land on the cutting edge of the cutting blade, the milling cutter is attached to the work axis of the electric discharge machine with the axis of the main spindle hole of the milling machine and the axis of the workpiece axis aligned. When the machine is removed from the processing machine and then mounted on the main shaft of the processing machine again, by using a centering mechanism or the like, the milling machine can be mounted in a state where the axis of the main shaft hole and the workpiece axis coincide. . Therefore, even after the land is formed, the land forming accuracy of the milling cutter can be maintained, and the outer peripheral runout accuracy can always be maintained at a high accuracy.

As a result, in milling using this milling machine, even if the feeding speed is increased, the knife mark is not conspicuous on the workpiece, so that the machining efficiency is improved without lowering the machining quality. Can be. Also,
As a cutting blade material, a high-hardness sintered body such as a diamond sintered body or a boron nitride sintered body is used. However, since lands are formed using electric discharge machining, harmful chipping occurs at the cutting edge. Land processing can be performed in a short time without any problems.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the milling cutter 10 has a cutting edge 12 made of a high-hardness sintered body such as a diamond sintered body, and has an arc-shaped surface centered on the rotation axis of the milling cutter. Has a land 13 having a thickness T in the axial direction of about 0.05 to 1 mm. Hereinafter, formation of the land 13 will be described.

As shown in FIGS. 2 and 3, the milling machine 10 is provided with a work shaft 21 provided on a table of an electric discharge machine 20.
Attach to Here, the milling shaft 10 is
A mechanism (centering mechanism) for matching the center of the inner circumferential circle of the main shaft hole 11 with the center of the work shaft 21 is provided.
Alternatively, a sleeve having a centering mechanism (Japanese Patent Publication No. Sho 5)
No. 7-49324). The discharge surface 22a of the block-shaped electrode 22 of the electric discharge machine is arranged facing the work axis 21, and the
When there is an outer peripheral runout, the discharge surface 22a is moved to a position slightly (for example, 0.03 mm) inside the radius of the cutting edge having the largest cutting edge radius.

While the electric discharge machine is in operation, the milling cutter 10 is rotated so that the cutting edge
When pressed against 2a, a land 13 composed of an arc-shaped surface is formed on the cutting edge. At the same electrode 22 position, milling 10
By machining all the cutting edges, a radius error of 0.
A land 13 surface located on the same circle within 01 mm can be formed. Milling 10
If the runout of the outer periphery of the
a is slightly moved further toward the work shaft 21 side,
The same processing may be repeated.

As described above, the center of the inner circumference of the main shaft hole 11 of the milling machine 10 is made to coincide with the center of the work shaft 21 of the electric discharge machine, and the milling machine 10 is rotated about its axis. The land 13 is formed with high precision by bringing the cutting edge of the cutting blade 12 into contact with the electrode 22 of the electric discharge machine. When the milling machine 10 is mounted on a main shaft of a processing machine, in order to suppress an outer peripheral runout error, by using a main shaft or a sleeve having the centering mechanism,
When using, the runout accuracy of the milling cutter is 0.01mm
Within a high accuracy.

As a result, in milling using the milling cutter 10, even when the material feeding speed is increased, the knife mark does not stand out, so that the machining efficiency can be improved without lowering the machining quality. In addition, although a high-hardness sintered body is used as a cutting blade material, since the lands 13 are formed using electric discharge machining, machining can be performed in a short time without causing harmful chipping. it can.

In the above embodiment, when the electric discharge machining consumes the discharge surface 22a of the electrode 22 and a machining error occurs between the cutting edges 12, the electrode 22 is moved in accordance with the consumption of the discharge surface 22a by the arrow in FIG. By processing each cutting edge by moving in the M direction, processing errors can be minimized.

When the milling machine 30 is a flat milling machine for plane machining, as shown in FIG. 4, even if the thickness t of the electrode 22 is less than the thickness T of the cutting edge 31 of the milling cutter, As shown by an arrow R in FIG. 5, each of the cutting edges is machined while repeating the normal and reverse rotations of the milling cutter 10 at the vicinity of contact with the cutting edge of the cutting blade 31, and at the same time, the electrode 22 is moved to the work axis 21.
By relatively moving in the direction (arrow S), the land can be processed. Alternatively, it is also possible to perform a partial processing of each cutting edge while rotating the milling machine 30 in a fixed direction, and at the same time, to add a movement for relatively moving the electrode 22 in the direction of the work axis 21.

When the milling cutter 40 is a full-form milling cutter, it is necessary to use a discharge surface 50a of the electrode 50 which is formed into a full-shape corresponding to the cutting edge 41, as shown in FIG. Further, in the case of the full-form milling cutter, an electrode 60 having a substantially V-shaped convex tip as shown in FIG. 7 is used. At the same time as processing the blade 41, the electrode 60 is relatively moved in the direction of the work axis as shown by the arrow S, and the distance between the electrode 60 and the work axis is adjusted so as to correspond to the shape of the entire mold. Become. Alternatively, partial cutting of each cutting edge 41 is performed while rotating the milling cutter 40 in a fixed direction, and at the same time, the distance between the electrode 60 and the work axis is adjusted so as to correspond to the shape of the entire mold while relatively moving the electrode 60 in the work axis direction. This also allows the land to be processed.

Next, a second embodiment will be described. In the present embodiment, the electrode shape of the electric discharge machine is changed to the disk-shaped electrode 70 instead of the block shape shown in the first embodiment. As shown in FIG. 8, the center axis (electrode axis) 71 of the electrode 70 was arranged parallel to the work axis 21, and the thickness of the electrode 70 was larger than the thickness of the milling cutter 10. After adjusting the distance between the two shafts 71 and 21, the cutting edge of the cutting blade 12 is pressed against the discharge surface 70a of the electrode 70 while rotating the milling cutter 10, and a land (not shown) having an arc-shaped surface is formed on the cutting edge. Was formed.

By forming the electrode 70 in a disk shape, the electrode can be continuously or intermittently rotated around the electrode axis depending on the state of wear of the electrode, so that the processing can be continued.
As shown in the embodiment, the entire cutting edge 1 of the milling cutter 10
A land surface located on substantially the same circle with a radius error of 0.01 mm or less can be formed on the second cutting edge. When the milling machine 10 is mounted on the main shaft of a processing machine, by using the main shaft and the sleeve having the centering mechanism, the outer peripheral runout accuracy of the milling machine 10 is maintained at a high accuracy within 0.01 mm during use. Can be.

As a result, in milling using the milling cutter 10, the knife mark is not noticeable even when the material feeding speed is increased, so that the machining efficiency can be improved without lowering the machining quality. Although a high-hardness sintered body is used as a cutting blade material of the milling cutter 10, since lands are formed by using electric discharge machining, the cutting blade 12 does not generate harmful chips and can be used for a short time. Can be processed.

When the milling machine 30 is a flat milling machine for plane machining, even if the thickness of the electrode is equal to or less than the thickness of the milling machine 30, the milling machine 30 is positioned near the electrode 70 in contact with the cutting edge. The land can be processed by processing the respective cutting edges while repeating the forward and reverse rotations and simultaneously moving the electrode 70 relative to the work axis direction.

When the milling cutter 40 is a full-form milling cutter,
What is necessary is just to make the discharge surface of the electrode 70 a shape corresponding to the overall shape. In the case of a full-form milling machine, as shown in FIG. 9, an outer periphery 81 uses a disk-shaped electrode 80 having a substantially V-shaped convex shape.
In the vicinity where the cutting edge comes into contact with 0, the respective cutting edges are machined while repeating the forward and reverse rotation of the milling machine 40, and at the same time, the electrode 70 is moved relative to the work axis direction while moving with the work axis so as to correspond to the shape of the entire mold. The land can be processed by adjusting the distance.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a part of a milling machine according to an embodiment of the present invention.

FIG. 2 is a plan view partially showing a processing state of the milling machine.

FIG. 3 is a side view partially showing a processing state of the milling machine.

FIG. 4 is a plan view partially showing a processing state of a flat milling machine.

FIG. 5 is a side view partially showing a processing state of a flat milling machine.

FIG. 6 is a plan view partially showing a processing state of the forming die milling machine.

FIG. 7 is a plan view partially showing a processing state of a mold milling machine having different electrode shapes.

FIG. 8 is a side view partially showing a milling process using a disk-shaped electrode according to a second embodiment.

FIG. 9 is a side view partially showing a processing state of a full-form milling machine using disk-shaped electrodes having different electrode shapes.

FIG. 10 is a perspective view schematically showing a surface state of a workpiece when the material feeding speed is increased by using a conventional milling machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Milling, 12 ... Cutting blade, 13 ... Land, 20 ... Electric discharge machine, 21 ... Work axis, 22 ... Electrode, 22a ... Electric discharge surface, 30 ... Flat milling, 31 ... Cutting blade, 40 ... Form milling machine, 41 ... Cutting blade, 50 ... Electrode, 50a ... Discharge surface, 60 ...
Electrode, 70: electrode, 70a: discharge surface, 71: central axis, 8
0 ... electrode.

Claims (1)

[Claims] 1. A milling machine having a land on a cutting edge of a cutting blade made of a high-hardness sintered body, wherein the milling cutter is provided on a work axis of an electric discharge machine, the axis of a main shaft hole of the milling machine and the axis of the work axis. The land is attached to the electrode of the electric discharge machine while rotating the milling cutter about its axis, so that the land is attached to the axis of the milling cutter. A milling cutter having a land on a cutting edge, wherein the milling cutter is formed in an arc shape with the center as a center.