JP3033166B2 - Rotary tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to diamond and cubic boron nitride (CB).
The present invention relates to a rotary tool having a cutting edge formed of a hard sintered body mainly composed of N) or the like.

[Conventional technology and its problems]

Conventionally, a hard sintered body used for this type of cutting blade has a fifth shape.
As shown in FIG. 6 and FIG. 6, a hard layer 22 made of diamond or CBN, and a support layer 23 made of a hard metal,
It is formed as a flat plate-shaped material, and is fixed to the tool body 20 by brazing the support layer and the seat surface in a state where the support layer 23 is grounded to the seat surface provided on the tool body 20.

However, when the flat hard sintered body 21 is directly attached to the tool body 20 and used as a cutting edge of a rotary tool such as an end mill or a reamer as described above, the shape of the cutting edge is limited by the shape of the sintered body. There is a problem that a sharp design cannot be made.

In other words, in a structure in which a plate-shaped hard sintered body is mounted in alignment with the axis of a tool, or is mounted with a slight inclination to make a rake angle, the cutting edge can have a large rake angle without twisting. There is a problem that sharpness cannot be significantly improved because it cannot be performed.

On the other hand, a method of twisting the rake face of the hard layer 22 of the sintered body to give a rake angle is also conceivable, but in order to make a rake angle on a long cutting edge in the axial direction, a sufficient thickness is required for the hard layer. become. However, the thickness of the conventional hard layer is only about 1 mm, and there is a drawback that only a small rake angle can be formed even if a lead is attached to the cutting blade within this thickness range.

Note that if the thickness of the hard layer is increased, the rake angle can be increased in accordance with the thickness, but in a structure in which the hard layer 22 and the support layer 23 are arranged so as to overlap in the rotation direction as shown in FIG. Increasing the thickness of the hard layer 22 inevitably reduces the thickness of the support layer 23, and has a disadvantage in that the fixing force between the hard sintered body and the tool body is reduced. Therefore, there is a problem that the support layer 23 cannot be made too thin, and the effective thickness of the hard layer 22 cannot be increased.

An object of the present invention is to solve the above-mentioned problem and to provide a structure capable of forming a twisted blade twisted at a large angle with respect to a hard sintered body.

[Means for solving the problem]

In order to solve the above problems, the present invention forms a twist groove which is circumferentially twisted on the outer periphery of a tool body, and laminates the hard sintered body with a hard layer and a support layer holding the hard layer in a tool radial direction. The hard layer and the support layer are formed into a structure in which the hard layer and the support layer are twisted along the twist groove, and the hard sintered body is oriented such that the support layer is on the rotation center side of the tool and the hard layer is on the outer circumference side of the tool. Thus, a twisted blade having a twist angle of 10 ° or more along the twisted groove was formed in the hard layer.

[Action]

In order to form the rotary tool having the above configuration, first, the hard sintered body is cut along the twist groove from the hard layer toward the support layer, and the twisted sintered body having a uniform thickness in a state where the hard layer is continuous. To form

Next, the sintered body is attached to the torsion groove of the tool body so that the hard layer faces outward, and the inner support layer and the tool body are brazed and fixed, and then the upper surface of the hard layer is twisted. A rake face is formed, and a twist blade is formed between the rake face and a side surface of the hard layer.

In the above structure, a hard layer that can be twisted with a uniform thickness along the torsion groove can be formed, so that a cutting edge that can be twisted at a large rake angle over the entire length even with a long cutting edge length can be formed.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the tool body 1 is made of a steel material such as an alloy steel formed in a cylindrical shape, and has a plurality of chips discharged in the axial direction from the end at the tip thereof. Notches 2 and 2 are formed. On the bottom surfaces of the notches 2, 2, there are formed torsional grooves 3, 3 which are circumferentially twisted from the tip toward the axial direction.
The hard sintered body 4 is grounded.

The hard sintered body 4 mounted on the tool body 1 is formed by integrally forming a hard layer 5 of diamond or CBN and a support layer 6 made of a cemented carbide by simultaneous sintering. Is formed in a plate material twisted so as to conform to the shape of.

The hard sintered body 4 is arranged such that the support layer 6 is disposed on the inner peripheral side and the hard layer 5 is disposed on the outer peripheral side, and is grounded to the torsion groove 3 of the tool body 1, and the support layer 6 and the torsion groove 3 are brazed. Is fixed.

A rake surface 7 that is twisted with a large rake angle is formed on the upper surface of the hard layer 5 facing the outer peripheral side, and a twist blade 8 is formed at a boundary between the rake surface 7 and the side surface.

The twist angle forming the above-mentioned twist blade 8 ranges from 10 ° to 60 °.
It is desirable to set within the range of ゜. That is, if the twist angle is not more than 10 °, the performance as a torsion blade, which reduces contact resistance, cannot be sufficiently exerted. Conversely, if the angle is more than 60 °, the twist is too large to produce a remarkable effect. Since a layer is required, there is a problem that leads to an increase in cost.

Next, a method of cutting the hard sintered body 4 from a material will be described.

FIG. 3 (a) is a side view as viewed from the axial cross section of a tool for conceptually showing a method of cutting a hard sintered body.
FIG. 3B is a plan view, and FIG. 3C is a front view.

In this case, in the conventional structure shown in FIGS. 5 and 6,
The hard layer and the support layer are cut out from the material of the plate-shaped sintered body so that the hard layer and the support layer are vertically stacked within the range of A which shows the cutting edge cross section in FIG. 3 (a). Since the thickness of the hard layer that can be effectively used as a blade becomes small, a large rake angle cannot be formed on the hard layer.

On the other hand, in the structure of the present invention, the plate-shaped sintered body material 9 is considered as a part of a columnar hard sintered body with respect to the tool body 1, and the support layer 6 has a hard inner side. Layer 5
The lead is cut from the hard layer 5 along the torsion groove 3 by a means such as wire cutting in a state in which the outer side is arranged outside. Thereby, the hard sintered body 4 twisted with a uniform width over the entire length can be cut out.

The cut and twisted sintered body 4 is attached to the torsion groove 3 of the tool body 1, and the support layer 6 and the torsion groove 3 are fixed by brazing. Then, the rake face 7 of the hard layer 5 disposed outside is twisted to form the twist blade 3.

As described above, since the hard layer 5 is cut into a twisted shape and is formed with a uniform width over the entire length in the axial direction, a twisted blade twisted at a large angle over the entire cutting edge even when the cutting edge length is increased. Can be.

By the way, as shown in FIG. 3 (a), in the material 9 in which the hard layer and the support layer are formed in parallel, the hard layer 5 is cut off at the portion (a) crossing the tool outer diameter 10, and the cutting edge length However, this can be solved by forming the boundary surface 11 between the hard layer 5 and the support layer 6 by an arc surface along the tool outer diameter 10 as shown in FIG. Can be. That is,
In the above structure, since the cut-out line is parallel to the boundary surface, a hard sintered body twisted with a uniform thickness can be effectively produced even with a long dimension. FIG. 4 (a)
(B) and (c) are a side view, a plan view, and a front view, respectively, showing a hard sintered body cut out from a material.

Further, in the structure of the present invention, as shown in FIG. 2, the hard layer 5 is formed into a twisted shape with a uniform width, so that the width that can be effectively used as a cutting edge can be increased.
Therefore, as shown in FIG. 5, the hard layer is formed in a flat plate shape and the lead of the twisted blade must be absorbed only by the thickness of the hard layer. In the case of forming a twist blade twisted by the above, the thickness of the hard layer can be set thinner in the structure of the present invention.

Actually, for a 15 mm diameter end mill, when a cutting edge having a blade length of 15 mm is formed using a hard sintered body having a hard layer thickness of 2 mm, the structure of the present invention forms a torsion blade having a twist angle of 30 °. However, in the conventional structure, only the inclined blade having a rake angle of 2 ° to 5 ° could be formed.

In addition, the twisted blade end mill of the present invention and the conventional 2 mm-
An aluminum die-cast work material was cut with a 5 mm inclined edge end mill at a peripheral speed of 300 m / min, a radial cut of 0.2 mm, an axial cut of 13 mm, and a feed of 0.2 mm / rev. As a result, in the conventional inclined blade end mill, chatter occurs, cutting noise is large, and surface roughness is poor (Rmax 12
μ). On the other hand, in the end mill with a twisted blade, no chatter was obtained under the same conditions, the cutting noise was small, a stable cutting state was obtained, the surface roughness was good (Rmax 4μ), and beautiful finishing accuracy was obtained.

〔The invention's effect〕

As described above, according to the present invention, since the hard layer of the hard sintered body is arranged on the outer peripheral side and formed in a twisted shape, it is possible to form a hard layer having a uniform thickness over a long cutting edge length. Thus, a twisting blade twisted at a large rake angle can be effectively formed.

Therefore, by using the structure of the present invention, the hard sintered body can be provided with a twisting blade twisted at a large angle, and there is an effect that a rotary tool having both high wear resistance and good sharpness can be provided.

[Brief description of the drawings]

1 is a front view showing a rotary tool according to an embodiment, FIG. 2 is a perspective view thereof, FIG. 3 (a) is a side view showing a method for cutting a hard sintered body, and FIG. 3 (b) is a plan view thereof. FIG. 3 (c) is a front view, FIG. 4 (a) is a side view showing the cut hard sintered body, FIG. 4 (b) is a plan view thereof, and FIG. 4 (c). Is a front view, FIG. 5 is a front view showing a conventional example,
FIG. 6 is a side view thereof. DESCRIPTION OF SYMBOLS 1 ... Tool main body, 3 ... Torsion groove, 4 ... Hard sintered body, 5 ... Hard layer, 6 ... Support layer, 7 ... Rake face, 8 ... Torsion blade, 10 ... Tool outer diameter , 11 …… the boundary surface.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23C 5/10

Claims (1)

(57) [Claims] 1. A rotary tool for attaching a hard sintered body to a tool body and forming a cutting edge in the hard sintered body, wherein a torsion groove twisted in a circumferential direction is formed on an outer periphery of the tool body. The body has a structure in which a hard layer and a support layer holding the same are laminated and integrated in the tool radial direction, and further, the hard layer and the support layer are twisted along the twist groove to support the hard sintered body. The layer is fixed in the torsion groove with the direction of rotation of the tool on the rotation center side and the hard layer on the outer peripheral side of the tool, and a twist angle of 10 ° or more along the torsion groove is formed on the hard layer. Characterized rotary tool.