JPH10315009A - Rotary cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary cutting tool in which attaching/detaching of a cutting tool is easy, there is no possibility of moving of a workpiece during the cutting work, the machining accuracy can be held for many hours, and an accurate taper angle can be obtained even in the case of a small workpiece. SOLUTION: A rotary cutting tool 1 is a cutting tool obtained by machining the tip end part of a piece of round, bar-shaped member 2, and two-in-a-set cutting edges 3, 3 are formed in a point-symmetrical manner and as an integrated body. Cutting edges 4, 4 facing to each other are inclined in the same inclination as that of a finished surface in the axial direction, and intersection part of the cutting edges 4a is connected with each other in a curve. In addition, a rake face 5 has an expanded-width part 5a for discharging chips, whose width is expanded toward the base part of the bar-shaped material 2. Since cutting at a high speed revolution can be carried out only by advancing or retreating the rotary cutting tool 1, a conical workpiece having higher accuracy can be obtained more quickly (than usual), and attaching/detaching of the tool 1 can be done easily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cutting tool which is fixed to a supporting member which performs a rotating operation and which cuts a leading end of a guided workpiece into a conical shape by abutting a cutting blade.

[0002]

2. Description of the Related Art Conventionally, when a tip of a workpiece such as a metal bar is cut into a conical shape, a cutting tool is brought into contact with a workpiece to be rotated and held, and the cutting tool is slid at the same gradient as a finished surface. While cutting.

[0003] As a device for performing cutting while rotating the cutting tool itself, for example, a rotary cutting machine described in Japanese Patent Application Laid-Open No. 3-202201 has been proposed. In this rotary cutting machine, a bite support member that rotates around a metal rod guided to an internal cutting space and a cutting edge fixed to the bite support member for cutting the metal rod are provided in the cutting space. It had a plurality of cutting tools protrudingly arranged, and the cutting edge of each cutting tool was arranged along the rotation axis direction such that the tip of the metal rod was located on the surface of the conical surface to be cut. .

In this rotary cutting machine, a metal bar is fixed to a support table, and a plurality of cutting tools are rotationally cut from the tip of the metal bar in a conical shape by the rotation of the spindle as the slide table advances. Also, the cutting tools are arranged at positions shifted stepwise along the axial direction of the metal bar, and are arranged radially at equal intervals in each row.

[0005] Since the cutting edge portion of the same row of cutting tools simultaneously contributes to the cutting process on the outer peripheral surface of the metal rod, there is an effect that the cutting amount per one cutting tool is averaged. Further, by inserting a metal rod into the row of cutting edges of a plurality of rotating cutting tools, the number of cutting tools sequentially contributing to cutting is increased, thereby shortening the processing time.

[0006]

However, in the conventional cutting method in which a cutting tool is brought into contact with a work to be held in rotation, if the work is not completely fixed, the work may escape in the opposite direction to the cutting tool during machining. In particular, in the case of small articles, the accuracy tends to be poor. Also, when the tip is rounded, chattering or the like may occur and the workpiece may be broken.

Further, in the case of a conventional rotary cutting machine, since a plurality of cutting edges are machined, it is troublesome to fix a large number of cutting edges at predetermined positions. It was also difficult to realize. In addition, it is not suitable for processing small items, and it cannot be cut with a rounded tip.

[0008] The present invention solves the above-mentioned problems, the work of attaching and detaching a cutting tool is easy, the work does not move during cutting, the processing accuracy can be maintained for a long time, and a small work can be obtained. It is an object of the present invention to provide a rotary cutting tool capable of obtaining an accurate taper angle even if it is provided. Another object of the present invention is to provide a rotary cutting tool capable of easily performing a cutting process in which a tip portion of a cone is rounded, and capable of cutting even when a blade angle is 90 degrees and a rake angle and a clearance angle are 0 degrees. I have.

[0009]

In order to solve the above-mentioned problems, a rotary cutting tool according to the present invention is fixed to a supporting member for performing a rotating operation, has a cutting space in which a cutting tool is projected, and has a guide. In a rotary cutting tool for cutting a processed workpiece into a conical shape by abutting a cutting blade, the cutting tool includes a pair of cutting edges integrally formed in a point-symmetric arrangement at a tip end of a single rod-shaped member. The opposed cutting blades are inclined at the same gradient as the finished surface in the axial direction, and each rake surface has a widened portion for chip discharge from the intersection of the cutting blades toward the base of the rod-shaped member. . The rotary cutting tool according to claim 2 is
The cutting edge intersection of the cutting edge is connected by a curve, the blade angle is 90 degrees,
The rake angle and the clearance angle are 0 degrees.

This rotary cutting tool advances while rotating the two blades fixed to the support member, and cuts the fixed work to be inserted into the cutting space in a manner that the opposed cutting blades hold. In addition, stable cutting can be performed without causing the workpiece to fall. Therefore, the accuracy of the perfect circle of the conical cross section is high, and the taper angle of the finished surface coincides with the angle of the cutting edge, so that no variation occurs.

The widened portion provided on one rake face intersects with the flank extension of the other cutting edge. The shape of the flank extension forms a curved surface so that chips can be smoothly discharged.

Further, by connecting the intersections of the cutting edges with a curved line, the tip of the cone can be rounded just by advancing the two blades. Further, since the opposed cutting blades sequentially cut from the end while clamping the workpiece, the blade angle is 90 °.
Even if the angle, rake angle, and clearance angle are 0 degrees, cutting is possible.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a perspective view of the rotary cutting tool of the present invention, FIG. 2 is a plan view of the rotary cutting tool, FIG. 3 is a front view of the rotary cutting tool, FIG. 4 is a left side view of the rotary cutting tool, and FIG. The rotary cutting tool 1 is a cutting tool obtained by processing the tip of one round rod-shaped member 2, and integrally forms a pair of cutting edges 3 and 3 in a point-symmetric arrangement. The opposed cutting edges 4 and 4 are inclined in the axial direction at the same gradient as the finished surface, the cutting edge intersections 4a are connected by a curve, and the rake face 5 is
Has a widened portion 5a for chip discharge toward the base direction.

The blade angle of the cutting edge 3 is β = 90 degrees, and the rake angle of the rake face 5 and the clearance angle of the flank 6 are 0 degree. One widened portion 5a intersects with the flank extension 6a of the other cutting edge 4, but the shape of the flank extension 6a is formed as a curved surface so that chips are smoothly discharged.

The rotary cutting tool 1 is fixed to a support member 8 of a spindle 7 connected to a motor (not shown) and rotates, and performs forward and backward operations by operating a slide table (not shown). On the other hand, a workpiece 9 such as a metal bar is fixed to a support table 10 and guides the workpiece 9 to a cutting space as the slide table advances, and comes into contact with the cutting blade 4 from the tip to form a cone. Cutting.

At this time, since the cutting edge intersections 4a are connected by a curve, the tip of the cone can be rounded only by moving the rotary cutting tool 1 forward. The opposite cutting edge 4,
Since the workpiece 4 is sequentially cut from the end while holding the workpiece 9, it is possible to cut even if the rake angle and the clearance angle are 0 degrees.
For this reason, manufacture of the rotary cutting tool 1 itself becomes easy,
This is advantageous in consideration of protection against impact, dissipation of cutting heat, and the like.

Further, since the cutting by high-speed rotation can be performed only by moving the rotary cutting tool 1 forward and backward, a work 9 with higher accuracy can be obtained faster. The material of the cutting edge 3 of the rotary cutting tool 1 is a cemented carbide, a natural diamond, or a Compax material. Further, the taper angle θ of the cutting blade 4 is desirably 20 to 40 degrees.

[0018]

As described above, the rotary cutting tool according to the present invention has a pair of cutting edges integrally formed in a point symmetric arrangement, and the opposite cutting edge is inclined at the same gradient as the finished surface. Therefore, the conical cutting can be performed only by advancing the rotary cutting tool. Further, since the workpiece is cut with the shape held by the opposing cutting blades, even a small workpiece can be stably cut without causing the workpiece to collapse. Therefore, the precision of the perfect circle of the conical cross section is high, and the taper angle of the finished surface matches the angle of the cutting edge, so that the dimensional accuracy of the workpiece can be maintained for a long time, and no variation occurs.

Further, since the rotary cutting tool only needs to make its axis coincide with the axis of the workpiece, the mounting and dismounting work becomes easy. Since each rake face has a widened portion for chip discharge from the intersection of the cutting blade toward the base of the bar-shaped member, chips are discharged smoothly.

In the rotary cutting tool according to the second aspect of the present invention, since the intersection of the cutting edges of the cutting edges is connected by a curved line, the tip of the cone can be easily rounded only by advancing the two blades. In addition, since the opposing cutting blades sequentially cut from the end while clamping the workpiece, cutting can be performed even when the blade angle is 90 degrees, the rake angle and the clearance angle are 0 degrees.

[0021]

[Brief description of the drawings]

FIG. 1 is a perspective view of a rotary cutting tool.

FIG. 2 is a plan view of the rotary cutting tool.

FIG. 3 is a front view of the rotary cutting tool.

FIG. 4 is a left side view of the rotary cutting tool.

FIG. 5 is a cross-sectional view showing a cutting state of the rotary cutting tool.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotary cutting tool 2 rod-shaped member 3 cutting edge 4 cutting blade 4a cutting blade intersection 5 rake face 5a widening part 6 flank

Claims (2)

[Claims] Rotational cutting which is fixed to a supporting member which performs a rotating operation, has a cutting space in which a cutting tool is protruded therein, and cuts a guided workpiece into a conical shape by abutting a cutting blade. In the tool, the cutting tool has a pair of cutting edges integrally formed in a point symmetrical arrangement at the tip of one rod-shaped member, and the opposing cutting edges are inclined in the axial direction at the same gradient as the finished surface. A rotary cutting tool, wherein each rake face has a widened portion for discharging chips from the intersection of the cutting blade toward the base of the rod-shaped member. 2. The rotary cutting tool according to claim 1, wherein the cutting edge has a cutting edge intersection connected by a curve, a cutting edge angle of 90 degrees, and a rake angle and a clearance angle of 0 degrees.