JP6660049B1 - End mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an end mill capable of simultaneously chamfering both ends of a cutting hole and improving working efficiency and working accuracy. A shank body (11) that rotates in an axial direction (P) is provided, and the shank body (11) has a milling part (A1) provided at an end thereof and a chamfering part (A2) provided on an outer peripheral surface thereof. The processed portion A2 has a constricted shape and is characterized in that in the axial direction P, the diameter is gradually reduced from both ends thereof toward the center thereof. [Selection diagram] Fig. 1

Description

  The present invention relates to an end mill.

  2. Description of the Related Art Conventionally, an end mill has been frequently used as a tool mounted on a milling machine or the like to perform cutting.

  The end mill is provided with a cutting edge at its tip and around the axis, and by rotating around the axis, it can perform various cutting processes such as peripheral cutting, shoulder cutting, grooving, curved surface cutting, and hole cutting. .

  As an invention relating to such an end mill, for example, Patent Literature 1 discloses an end mill having two pedestals extending axially forward from one end of a shank main body, a tip fixed to the tip of one of the pedestals, and an end mill blade. An end mill with a chamfered blade, in which the end mill blade and the chamfered blade are formed separately by forming a chamfered cutting portion having a chamfering blade by forming a cutting portion and fixing a chip to the tip of the other pedestal, is described. ing.

  Japanese Patent Application Laid-Open No. H11-163873 discloses a first all-blade provided with a cutting blade for cutting the bottom and side surfaces of a keyway, and a stepped shape inclined at an upper portion of the first all-blade. A method of processing a scroll member using an end mill integrally configured with a second cutting blade having a chamfering cutting blade for cutting is described.

  Further, in Patent Document 3, a chamfered blade insertion hole is formed in a cylindrical frame having an inner diameter through which an end mill can penetrate and provided with a set screw for fixing the end mill, and the chamfered blade insertion hole is chamfered. An end mill-mounted chamfering tool is disclosed in which a bar-shaped chamfering blade having a cutting blade portion is removably inserted and provided with a set screw for fixing the chamfering blade to a frame.

JP 2005-238414 A JP 2003-139074 A Japanese Patent No. 4016069

  The inventions described in Patent Documents 1 to 3 described above are related to an end mill capable of simultaneously performing milling and chamfering.

  By the way, such a conventional end mill can simultaneously perform the milling process and the chamfering process only on one surface on which the starting end of the cutting hole is formed.

  Therefore, for example, when a through hole is provided in a plate material and chamfering is performed on both ends of the through hole, a user of the end mill is required to re-position the end mill with respect to a surface on which the starting end of the cutting hole is not formed. , Milling and chamfering.

That is, in such a case, the user is forced to divide the processing steps into two steps, resulting in deterioration of processing efficiency.
In addition, re-positioning of the end mill causes an error in the processing position of each surface, resulting in deterioration of processing accuracy.

  The present invention has been made in view of the above situation, and provides an end mill capable of simultaneously performing chamfering on both ends of a cutting hole and improving machining efficiency and machining accuracy. Make it an issue.

In order to solve the above problems, the present invention provides:
Equipped with a shank body that rotates in the axial direction,
The shank body has a milling portion provided at an end thereof and a chamfered portion provided on an outer peripheral surface thereof,
The chamfered portion has a constricted shape, and is gradually reduced in diameter in the axial direction from both end portions toward a central portion thereof.

  According to the present invention, the chamfered portion has a constricted shape, and is gradually reduced in diameter in the axial direction from both ends thereof to the center thereof, so that the length of the chamfered portion is substantially the same as the axial length. If the members are the same or have a thickness smaller than the length in the axial direction, it is possible to simultaneously chamfer the through holes and the upper and lower ends of the end faces provided in the members.

  In a preferred embodiment of the present invention, a plurality of the chamfered portions are provided along the axial direction.

  With such a configuration, even when the blade of one chamfered portion is deteriorated, the sharpness during the chamfering can be maintained for a long time by using another chamfered portion. .

  In a preferred aspect of the present invention, the plurality of chamfered portions have different thicknesses in the axial direction.

  With such a configuration, it is possible to perform chamfering on members having different thicknesses with one end mill according to the present invention.

  In a preferred embodiment of the present invention, a maximum diameter of the chamfered portion is equal to or less than a maximum diameter of the milled portion.

  With such a configuration, the milling process and the chamfering process can be performed smoothly. That is, with such a configuration, the end mill according to the present invention can be inserted into the through hole provided in the member by moving the milling portion straight in the axial direction. Thus, the chamfering can be performed immediately.

  In a preferred embodiment of the present invention, in a cross section orthogonal to the axial direction of the chamfered portion, the chamfered portion is bisected in the axial direction by a plane passing through the cross section having a minimum cross-sectional area. It is characterized by.

  With such a configuration, it is possible to chamfer the through holes provided in the member and the upper end and the lower end of the end face in the same shape.

  In a preferred embodiment of the present invention, the chamfered portion is formed to be curved in the axial direction.

  With such a configuration, it is possible to improve the processing efficiency and the processing accuracy of the R chamfering processing.

  ADVANTAGE OF THE INVENTION According to this invention, the chamfering process can be performed simultaneously to both ends of a cutting hole, and the end mill which can improve machining efficiency and machining accuracy can be provided.

It is a front view of the end mill concerning the embodiment of the present invention. It is a figure which shows the end mill which concerns on embodiment of this invention, Comprising: (a) It is a partial enlarged front view, (b) It is XX sectional drawing. FIG. 4 is a schematic perspective view illustrating a method of using the end mill according to the embodiment of the present invention. FIG. 4 is a schematic perspective view illustrating a method of using the end mill according to the embodiment of the present invention. FIG. 4 is a schematic perspective view illustrating a method of using the end mill according to the embodiment of the present invention. FIG. 4 is a schematic perspective view illustrating a method of using the end mill according to the embodiment of the present invention. It is a partial enlarged front view which shows the example of a change of the end mill which concerns on embodiment of this invention.

Hereinafter, an end mill according to an embodiment of the present invention will be described with reference to FIGS.
The embodiment described below is an example of the present invention, and the present invention is not limited to the following embodiment. In these figures, reference numeral 1 indicates an end mill according to the present embodiment.

As shown in FIG. 1, the end mill 1 includes a substantially cylindrical shank body 11 that rotates in the axial direction P.
The shank main body 11 includes a processing portion A in which a blade for processing a member is formed, and a shank main body B for attaching a tool (not shown) for rotating the shank main body 11 during the member processing. .

  The processing part A has a milling processing part A1 provided at an end thereof and a chamfering processing part A2 provided on an outer peripheral surface thereof.

  The milling portion A1 has a bottom edge formed as a ball end edge, but is not limited thereto, and may be a square end edge, a radius end edge, a drill edge, or the like, and is not particularly limited. Also, various shapes such as a normal blade, a tapered blade, and a roughing blade can be adopted for the outer peripheral blade.

The four chamfered portions A2 are provided along the axial direction P.
Here, the respective chamfered portions A2 are referred to as a first chamfered portion A2a, a second chamfered portion A2b, a third chamfered portion A2c, and a fourth chamfered portion A2d in order from the shank body main portion B side. And
The number of chamfered portions A2 is not limited to four, but may be any number.

More specifically, each of the chamfered portions A2a to A2d has a constricted shape and is formed to be curved in the axial direction P. The chamfered portions A2a to A2d have different axial thicknesses.
Here, the axial thicknesses of the chamfered portions A2a to A2d are referred to as thicknesses ta to td, respectively.

  As shown in FIG. 2A, the maximum diameter DA2 of the chamfered portion A2 is substantially the same as the maximum diameter DA1 of the milled portion A1.

FIG. 2B is a cross-sectional view taken along the line XX in FIG.
More specifically, the XX line coincides with the line connecting the vertices of the left and right arcs of the first chamfered portion A2a in FIG. 2A, and FIG. 2B passes through the XX line and extends in the axial direction. It is sectional drawing at the time of cutting by the plane orthogonal to P.

That is, the cross section S has the smallest cross sectional area among the cross sections obtained by cutting the first chamfered portion A2a along a plane perpendicular to the axial direction P.
The first chamfered portion A2a is configured to be bisected in the axial direction P by a plane passing through the XX line and orthogonal to the axial direction P.

  The above configuration is the same for the other chamfered portions A2b to A2d. In FIG. 2A, the respective arcs of the chamfered portions A2a to A2d are formed with the same radius of curvature.

In FIG. 2A, the size of the arc of each of the chamfered portions A2a to A2d, that is, the size of R, is not limited to this, and it is not necessary to sequentially reduce the size from the shank body main portion B side. For example, the shank main portion B may be formed sequentially larger from the main portion B side, or may be all the same size.
Also, the respective arcs of the chamfered portions A2a to A2d do not necessarily need to be formed with the same radius of curvature.

  Hereinafter, a method of using the end mill 1 will be described with reference to FIGS.

In the present embodiment, an example in which the substantially rectangular thin plate material Z shown in FIG. 3 is processed using the third chamfered processing portion A2c will be described.
It is assumed that the thickness Zt of the thin plate material Z is substantially the same or slightly smaller than the thickness tc of the third chamfered portion A2c.

  First, a user of the end mill 1 attaches a tool (not shown) for rotating the shank main body 11 to the shank main body B of the end mill 1, and rotates the end mill 1 (arrow a) while milling the part A1. Is pressed against the sheet material Z (arrow b).

By doing so, as shown in FIG. 4, a through hole H is formed in the thin plate material Z by the bottom blade and the outer peripheral blade of the milling portion A1.
FIG. 4 is a cross-sectional view taken along line YY in FIG. 3 for convenience of explanation.

  Next, the user moves the end mill 1 in the surface direction of the thin plate material Z to bring the third chamfered portion A2c into contact with the inner peripheral surface of the through hole H including the opening end (arrow c).

In this way, as shown in FIG. 5, the inner peripheral surface of the third chamfered portion A2c can be chamfered while expanding the area of the through hole H by the outer peripheral edge.
FIG. 5 is a sectional view taken along the line YY in FIG. 3, as in FIG.

  Further, the user can arbitrarily move the end mill 1 in the surface direction of the thin plate material Z to form a through hole of an arbitrary shape in the thin plate material Z while performing chamfering as shown in FIG. can do.

  In addition, the user makes the third chamfered portion A2c of the end mill 1 abut not only on the inner peripheral surface of the through hole H but also on each end surface of the thin plate material Z as shown in FIG. The thin sheet material Z can be machined into an arbitrary outer shape while chamfering.

  In the present embodiment, an example of processing using the third chamfered portion A2c has been described. However, other chamfered portions A2a, A2b, and A2d are naturally formed according to the thickness of the member to be processed and the processing content. Can be used.

  According to the present embodiment, each chamfered portion A2 has a constricted shape and is formed to be curved in the axial direction P, so that the through hole H provided in the thin plate material Z and the upper end of each end face and The lower end can be simultaneously chamfered.

  Further, since the plurality of chamfered portions A2a to A2d are provided along the axial direction P, even if the blade of one chamfered portion A2 is deteriorated, another chamfered portion A2 is used. This makes it possible to maintain the sharpness during chamfering for a long period of time.

  Further, since the thicknesses ta to td in the axial direction P of the chamfered portions A2a to A2d are different from each other, it is possible to perform chamfering on members having different thicknesses with one end mill 1.

Further, since the maximum diameter DA2 of the chamfered portion A2 is substantially the same as the maximum diameter DA1 of the milled portion A1, milling and chamfering can be performed smoothly.
That is, with such a configuration, the milling portion A1 is made to move straight in the axial direction P, so that the processing portion A can be inserted into the through hole H provided in the thin plate material Z. The chamfering process can be immediately performed on the hole H.

  Further, in a cross section orthogonal to the axial direction P of each of the chamfered portions A2a to A2d, each of the chamfered portions A2a to A2d is bisected in the axial direction P by a plane passing through a cross section having the smallest cross-sectional area. With this configuration, it is possible to chamfer the through hole H provided in the thin plate material Z and the upper end and lower end of each end face with the same R shape.

  It should be noted that the various shapes, dimensions, and the like of the respective components shown in the above-described embodiment are merely examples, and can be variously changed based on design requirements and the like.

For example, as shown in FIG. 7, each of the chamfered portions A2a to A2d may be formed in a tapered shape that gradually decreases in diameter at a constant gradient from each upper end and lower end toward each central portion, instead of a curved shape. .
Thereby, it becomes possible to improve the processing efficiency and the processing accuracy of the C chamfering processing.

Reference Signs List 1 end mill 11 shank main body A processing part A1 milling processing part A2 chamfering processing part A2a first chamfering processing part A2b second chamfering processing part A2c third chamfering processing part A2d fourth chamfering processing part B shank main part P axial direction Z thin Plate H Through hole

Claims (5)

Equipped with a shank body that rotates in the axial direction,
The shank body has a milling portion provided at an end thereof and a chamfered portion provided on an outer peripheral surface thereof,
The chamfered portion is provided in a plurality along the axial direction, has a constricted shape, in the axial direction, gradually reduces the diameter from both ends thereof toward the center thereof,
The plurality of chamfered portions are provided at intervals in the axial direction ,
The axial thicknesses of the plurality of chamfered portions are different from each other,
An end mill wherein the constricted shapes of the plurality of chamfered portions are similar in a front view . The end mill according to claim 1 , wherein a maximum diameter of the chamfered portion is substantially equal to a maximum diameter of the milling portion. Maximum diameter of the shank body provided between the maximum diameter and the plurality of chamfered portions of the plurality of chamfered portion is characterized by a maximum diameter substantially the same of the milling unit, according to claim 1 An end mill according to item 2 . In a cross section perpendicular to the axial direction of the chamfered portion, the chamfered portion is a plane through the cross sectional area is minimized, characterized in that it is bisected in the axial direction, claim The end mill according to any one of claims 1 to 3 . The end mill according to claim 1 , wherein the chamfered portion is formed to be curved in the axial direction.