JP2557737Y2 - Cutting tool cutter body and cutting tool - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cutting tool having a detachable tip mounted on a tip mounting seat of a cutter body.

[0002]

2. Description of the Related Art As a cutting tool for machining a metal material such as cast iron, a throw-away tip made of a hard material such as a cemented carbide is mounted on a tip mounting seat of a cutter body having a shank serving as a mounting portion to a machine tool. Hereinafter, it is abbreviated as a chip.)
There has been known a throw-away type cutting tool in which a cutting tool is detachably attached. This type of cutting tool has a characteristic that stress is concentrated on a portion where the bottom surface and side wall of the tip mounting seat of the cutter body and the surface of the cutter intersect with each other, and cracks are easily generated. Therefore, for example, Japanese Patent Application No. 61-121794.
As described in the above item, stress concentration is formed by forming a chamfered surface which is depressed inward of the cutter body at a portion where the bottom surface and the side wall of the chip mounting seat and the outer peripheral surface of the cutter body intersect each other. There has been proposed one that avoids cracking. However, the one that relies on such a chamfered surface is effective in avoiding stress concentration in the immediate vicinity of the cutter surface, but at the position where it enters from the cutter surface, the intersection between the chip mounting seat bottom surface and the side wall still exists. May intersect in an edge shape, stress may be concentrated and cracks may occur.

Therefore, as shown in FIGS. 8 to 10, for example, the intersections 5 and 6 between the bottom surface 2 and the side walls 3 and 4 of the chip mounting seat 1 are connected to the cutter surfaces 7 and 8, respectively. by forming the cross section arcuate cutout grooves 9 and 10 from a position intersecting extending a predetermined length toward the inside of the cutter body H _1, these intersection portions 5 and 6 from the intersection 5,6 eliminates the edge There is provided one in which cracking of the steel is prevented. Then, in the cutter body H ₁ shown in these drawings, by cutting into the straight drill along the intersection 5,6 from the cutter surface 7,8, to form a cutout groove 9,10.

[0004]

Meanwhile [devised SUMMARY], the cutter body H ₁ shows a conventional 8 to 10 described above, even if effective in preventing cracking of the intersection 5,6, cutout groove 9,10
As a result, the intersections 5 and 6 are largely scraped off, so that the amount of back metal behind the bottom surface 2 and the side walls 3 and 4 may decrease, and the strength of the cutter body may be impaired. When the thus insufficient strength of the cutter body H ₁ is, because can not be increased load during cutting, there was a significant impact on the performance of a cutting tool such as the machining efficiency during roughing fall. The present invention has been made under such a background, and it is possible to prevent a crack at an intersection between a bottom surface and a side wall of a chip mounting seat and increase the strength of the cutting tool and the cutter body. An object of the present invention is to provide a cutting tool having a high cutting performance using the same.

[0005]

In order to solve the above-mentioned problems, a cutter body according to the present invention has a bottom surface intersecting at least one cutter surface, and a side wall rising from the bottom surface and intersecting the cutter surface. in the cutter body of the cutting tool tip mounting seat is provided, at the intersection between the bottom surface and the side wall of the chip mounting seat, from the cutter surface to cross the bottom and side walls, along the intersection above notched groove extending inwardly of the cutter body is formed, the depth from the depth and the side wall from the bottom surface of the notched groove, and from the cutter surface to cross the bottom and side walls along said intersection above It is characterized in that it gradually decreases as it goes inward of the cutter body. Then, in order to enhance the effect of preventing cracking at the intersection between the bottom surface and the side wall of the chip mounting seat, the wall surface of the notch groove may be formed in an arc-shaped cross section.

Further, in the cutting tool of the present invention, a throwaway tip having a cutting edge is brought into close contact with the bottom surface of the tip mounting seat on the tip mounting seat of the cutter body, and the side surface thereof is connected to the side surface of the cutting tool. The chip mounting seat is detachably attached to the side wall of the chip mounting seat.

[0007]

According to the cutter body having the above construction, since the notch groove is formed at the intersection between the bottom surface and the side wall of the tip mounting seat, the bottom surface and the side wall do not intersect in the form of an edge. The stress generated in the part is reduced. And since the depth of the notch groove decreases toward the inside of the cutter body, the volume at which the intersection of the bottom surface and the side wall of the chip mounting seat is cut off by the notch groove gradually decreases, and as a result, the chip mounting seat is reduced. The back metal behind the intersection increases. Further, by forming the wall surface of the notch groove into an arc-shaped cross section, stress concentration in the notch groove can be avoided.

Further, according to the cutting tool having the above-described structure, the strength of the cutter body is high and breakage is unlikely to occur, so that the feed amount and the cutting depth during cutting can be made large.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 to 5, the cutter body H ₂ according to the present embodiment is provided with a cylindrical shank 20 to be mounted on a machine tool, and coaxially formed by reducing the diameter of the shank 20 by one step at the tip side. And a formed chip mounting portion 21. The chip mounting section 21, the second cutter body H ₂
A chip pocket 24 is formed on one surface, i.e., an outer peripheral surface 22 and a distal end surface 23.
A chip mounting seat 25 is formed on one side in the circumferential direction of 4. Chip mounting seat 25, the outer peripheral surface 22 of the cutter body H ₂
And a bottom surface 26 intersecting with the tip surface 23, a first side wall 27 rising from the bottom surface 26 and intersecting the outer peripheral surface 22,
And a second side wall that rises from the bottom surface and intersects the tip surface.

Then, the intersection 2 between the bottom surface 26 and the side wall 27
The 9, and the these bottom surface 26 and sidewalls 27 from the outer peripheral surface 22 that intersect, cutout grooves 30 extending a predetermined length radially inwardly of the cutter body H ₂ along the intersecting portion 29 is formed. Similarly, the intersections 31 between the bottom 26 and the side wall 28, a predetermined length from the distal end surface 23 and these bottom surface 26 and side walls 28 intersect along the intersection 31 in the axial direction inwardly of the cutter body H ₂ An extended notch groove 32 is formed.

As shown in more detail in FIGS. 2 and 3, the notches 30 and 32 have wall surfaces having an arcuate cross section. And the depth from the bottom surface 26 and the side wall 27 of the notch groove 30 is
The cutter body H ₂ extends along the intersection 29 from the outer peripheral surface 22.
Gradually decreases toward the inside in the radial direction. Similarly, the depth of the notch groove 32 from the bottom surface 26 and the side wall 28 is
The cutter body H ₂ extends from the tip surface 23 along the intersection 31.
Gradually decreases toward the inside in the axial direction. In addition,
In the figure, reference numeral 33 denotes a screw hole for mounting a chip, and 34 denotes a screw hole for preventing interference between an intersection between the side walls 27 and 28 and a corner of a chip mounted on the chip mounting seat 25 and at the intersection. An escape portion for preventing stress concentration.

Here, the notch groove 30 is formed by various methods. In this embodiment, as shown in FIGS. 3 and 4, a small-diameter end mill M is obliquely inclined with respect to the intersection 29. Is formed by cutting the end mill M in the radial direction. Incidentally, the degree of inclination of the end mill M may be changed according to the shape of the notch groove 30, but in the illustrated example, inclined obliquely tip mounting seat 25 by θ with respect to the bottom surface 26 from the tip end of the cutter body H ₂ When looking at it (Fig. 4)
The axis S is set to be inclined by φ with respect to the bottom surface 26,
These set angles θ and φ are θ = 45 ° and φ = 15 °.

[0013] In the cutter body H ₂ configured as described above, as shown in FIGS. 5-8, to the chip mounting seat 25, the chip mounting seat 25 chip 41 and the lower surface 42 having a cutting edge 40 The clamp screw 4 is inserted into the mounting hole 45 in a state in which the bottom surface 26 is in close contact with the side surfaces 43 and 44 of the chip mounting seat 25 and the side surfaces 43 and 44 are in contact with the side walls 27 and 28.
It is fastened at 6 and attached detachably. The end mill E of this embodiment is configured by attaching the tip 41. Note that the chip 41
It is a well-known material in which a hard material such as a cemented carbide or a cermet is formed into a flat plate shape having a parallelogram in plan view.

In the cutter body H ₂ of this embodiment, notches 30 and 32 are formed at intersections 29 and 31 between the bottom surface 26 of the chip mounting seat 25 and the side walls 27 and 28, so that these bottom surfaces 26 and Since the side walls 27 and 28 do not intersect in an edge shape, cracks from the intersections 29 and 31 are prevented in the same manner as in the conventional example shown in FIG. Moreover, since the wall surfaces of the notch grooves 30 and 32 are rounded in an arcuate cross section, there is no possibility that stress concentration occurs in the notch grooves 30 and 32, and the effect of preventing cracks is further enhanced. Also, the notch grooves 30, 32
Because There is shallower as it goes inward of the cutter body H _2, intersections 29, 31 by these notched grooves 30 and 32
Is reduced compared to the conventional case. Therefore, an increase in back metal amount left behind these bottom surface 26 and side walls 27 and 28, increasing the strength of the cutter body H ₂ is.

In this embodiment, the intersections 29, 31
Since the notched grooves 30 and 32 are formed by obliquely pressing the outer peripheral side of the small-diameter end mill M with respect to the end mill M, a discontinuous edge corresponding to the tip angle of the drill is formed as shown in FIG. Not to be left in the mounting seat, notch grooves 30, 32
The ridge lines L ₁ , L ₂ of the intersection of the bottom 26 and the side walls 27, 28 smoothly curve. Therefore, the occurrence of cracks at the intersections 29 and 31 is more reliably prevented.

According to the end mill E using the cutter body H ₂ of the present embodiment, the cutter body H ₂ is prevented from cracking and the strength itself of the cutter body H ₂ is increased. In addition, the cutting depth can be increased as compared with the conventional case, thereby improving cutting performance.

[0017] Although particular forms a notched groove 30, 32 on both the side walls 27, 28 in this embodiment, the present invention is not limited thereto, for example, cutting load F of the cutter body H ₂ axes In the case of acting exclusively in the direction (see FIG. 5), the cutout groove 32 may be omitted because a large load is not applied to the side wall 28 side. Etc. When the cutting load in the opposite acts exclusively in a radial direction of the cutter body H ₂ is omitted cutout groove 30, it is either formed on only one or to form them in both the cross section 29 and 31, cutting conditions May be appropriately selected according to the conditions.

Further, although this embodiment is given an end mill as an example, other boring bars and bytes, etc., be used in all types of cutting tools is a matter of course.

[0019]

As described above, according to the cutter body of the present invention, cracks at the intersections between the bottom surface and the side walls of the chip mounting seat are prevented, and the intersections between these bottom surfaces and the side walls are notched grooves. As a result, an excellent effect of increasing the strength of the cutter body is obtained by increasing the back metal behind the tip mounting seat by reducing the volume scraped off as compared with the conventional case.
Moreover, by forming the wall surface of the notch groove into an arc-shaped cross section, stress concentration in the notch groove is avoided, and the effect of preventing cracks is further enhanced. According to the cutting tool using the cutter body, since there is little possibility that the cutter body is cracked and the strength itself of the cutter body is high, it is possible to increase a feed amount and a cutting amount at the time of cutting. Cutting performance is obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a cutter body according to an embodiment of the present invention as viewed from a direction I in FIG. 6;

FIG. 2 is a view as seen from an arrow II in FIG. 1;

FIG. 3 is a view as seen from the direction of arrow III in FIG. 1;

FIG. 4 is a view from arrow IV in FIG. 3;

FIG. 5 is a plan view of the end mill according to the embodiment of the present invention;

FIG. 6 is a view from arrow VI in FIG. 5;

FIG. 7 is a view as seen from the direction of the arrow VII in FIG. 6;

FIG. 8 is a view showing a state where a tip mounting seat of a cutter body of a conventional end mill is viewed from a side facing a bottom surface thereof.

FIG. 9 is a view as viewed from the direction IX in FIG. 8;

FIG. 10 is a view as seen from the X direction in FIG. 9;

[Explanation of symbols]

Reference Signs List 22 Outer peripheral surface of cutter body 23 Tip surface of cutter body 25 Chip mounting seat 26 Bottom of chip mounting seat 27, 28 Side wall 29, 31 of chip mounting seat Intersection between bottom surface and side wall 30, 32 Notch groove 40 Cutting blade 41 Throw side E end mill H ₂ cutter body of the lower surface 43, 44 cutting insert away tip 42 indexable

Claims (3)

(57) [Scope of request for utility model registration] 1. A cutter body of a cutting tool, comprising: a tip mounting seat having a bottom surface intersecting at least one cutter surface and a side wall rising from the bottom surface and intersecting the cutter surface. At the intersection of the bottom surface and the side wall of the seat,
From the cutter surface to cross the bottom and side walls, those
Notched groove extending inwardly of the cutter body is formed along the intersection difference portion, the depth from the depth and the side wall from the bottom surface of the notch groove from the cutter surface to cross the bottom and side walls cutter body of a cutting tool, characterized in that as it goes along the intersection inwardly of the cutter body, are gradually decreased. 2. The cutter body according to claim 1, wherein a wall surface of the notch groove is formed in an arc-shaped cross section. 3. The insert mounting seat of the cutter body according to claim 1 or 2, wherein a throw-away tip having a cutting edge is brought into close contact with the bottom surface of the tip mounting seat, and a side surface thereof is mounted on the tip mounting seat. A cutting tool which is detachably attached by being brought into contact with the side wall of the mounting seat.