JPH08294814A - Cutting tool - Google Patents

Abstract

PURPOSE: To stably and firmly position an installing position of a tool tip and its holder with high accuracy, and also lengthen a service life of the tool tip. CONSTITUTION: A tool tip 1 to perform cutting work and a tool holder to hold the tool tip 1 are arranged so as to be freely mountable and demountable. Cutting edges 2 are formed in both end parts of the tool tip 1, and on both obverse and reverse planes, step differences 6 are formed on respective surfaces so as to cross each other in a V shape on a plane of projection. Inverse step differences to engage with the step differences 6 of the tool tip 1 are also arranged on tip installing surfaces sandwiching the tool tip 1 on the tool holder side so as to cross each other on a plane of projection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool such as a so-called throw-away type drill or end mill.

[0002]

2. Description of the Related Art Conventionally, many drills and end mills have been generally used in the production of various machine parts and molds.
In these processes, cutting tools with higher wear resistance have been required in recent years, but the corresponding tool material cost is also high, and the blade part and shank part are integrated with the same material. The so-called solid type cutting tool has a problem that the tool cost is considerably high.
On the other hand, a cutting tool has been made in which an inexpensive shank material is used and only the blade part is formed of a tool material, and both are brazed with silver solder, but this also causes the blade part to gradually wear out after several regrinds. In addition, advanced technology has been required for regrinding.

Therefore, a so-called mechanical clamp type cutting tool for mechanically fixing the tip blade portion to a shank has been developed. The blade tip is given a shape by the tool maker, and the user re-creates it as a throw-away type tool tip. Some are disposable without the need for grinding. Among these general turning inserts and face milling inserts, some inserts can be used several times by utilizing several ridges and corners depending on the shape of the tool insert.

[0004]

However, in high value-added drills for drilling holes and ball end mills, a cutting edge is provided only on one side of the tip, and the other end is attached to a holder and for positioning. The shape was formed.

Further, if cutting edges can be provided at both ends of the throw-away tip of a drill or an end mill, the tool material cost is almost the same as that of a conventional single-headed tip, and the cutting edge machining cost is slightly increased, but both end portions are increased. Since it becomes a cutting edge, the tool cost per blade can be cut in half.

However, when both ends are cutting blades, the cutting blade at the other end of the cutting blade is on the fixed side of the holder, so the cutting blade is used for positioning for fixing, and the sharp cutting blade is damaged. In addition, there is a problem in that when a cutting edge that is worn or chipped due to cutting is directly used on the fixed side, the positioning and mounting accuracy is reduced and the positioning becomes extremely unstable.

The present invention is to provide a cutting tool that can position the throw-away type tool tip and its holder firmly and stably with high precision and has a long tool tip life. To aim.

[0008]

SUMMARY OF THE INVENTION The present invention is a cutting tool in which a tool tip for performing a cutting process and a tool holder for holding the tool tip are detachably provided, and both ends of the tool tip are provided. Is formed with a cutting edge 2, and a step is formed on each of the front and back planes so as to intersect each other in a V shape on the projection plane, and a chip mounting surface for sandwiching the tool chip on the tool holder side. In addition, the cutting tool is provided with a reverse step which engages with the above-mentioned gap so as to intersect with each other on the projection plane.

Further, according to the present invention, the step is formed on both the front and back planes of the tool tip so as to correspond to the cutting edges at both ends and to be vertically arranged so as to intersect each other in a V shape on the projection plane at both upper and lower ends. It is formed on both ends and each surface, and is further formed linearly in rotational symmetry with each other.

[0010]

According to the cutting tool of the present invention, the wedge-shaped portions formed by the steps formed on both sides of the tool tip do not damage the cutting edge and are worn by the cutting edge during mounting and positioning fixing to the tool holder. And when chipping occurs,
It can be fixed independently of the cutting edge. Further, since the tool tip is attached by pressing it against the wedge surface, it can be attached with high accuracy even when the same tip is repeatedly attached. Further, since the cutting blades are provided on the upper and lower sides and the upper and lower sides and the front and back sides are formed in rotational symmetry, one tool tip is
It can be used twice and can be easily installed without worrying about the direction.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cutting tool according to an embodiment of the present invention will be described below with reference to the drawings. In the cutting tool of this embodiment, as shown in FIGS. 1A and 1B, cutting blades 2 are symmetrically formed at both upper and lower ends of a plate-shaped tool tip 1 and a through hole 4 is formed therebetween. It is formed in a symmetrical position. Further, a step 6 is formed on each of the two surfaces at an irrelevant position that does not affect the cutting edge 2 so as to correspond to the cutting edge 2 and form one side of the wedge shape. The step 6 is formed on both sides of the tool tip 1 so as to be rotationally symmetrical to each other in the vicinity of the cutting edge 2 corresponding to the upper and lower cutting edges 2, and as shown in FIG. The step 6 formed toward the center of the tip of the cutting blade 2 is formed obliquely so that the projection lines intersect with each other near the tip. That is, the wedge shape is formed by the steps 6 on the front and back surfaces.
Further, the upper and lower steps 6 are used for positioning when mounting a pair of steps 6 distant from the cutting edge 2 on the side to be used.

Step 6 provided on both sides of the tool tip 1
Is set according to the size of the tool tip 1, etc.
It is set to about 0.3 mm to 0.6 mm, and is formed to be 0.5 mm for the φ20 ball end mill of this embodiment.

As shown in FIGS. 3 to 5, the tool holder 8 to which the tool tip 1 of this embodiment is attached is such that the tool tip 1 is clamped by the tip attachment portion 9 at the tip of the tool holder 8. A pair of mounting surfaces 9a is formed with a gap. On the tip mounting surface 9a, reverse steps 10 capable of engaging with a pair of front and back steps 6 on one end side of the tool tip 1 are rotationally symmetrical to each other and are obliquely formed so as to intersect each other at a constant interval. Has been formed. The reverse step 10 is formed to be substantially equal to the height of the step 6.

Mounting holes 11 and 12 for fixing the tool tip 1 are formed in the tip mounting portion 9, respectively. As shown in FIG. 5, screws 14 and 16 are respectively inserted into the mounting holes 11 and 12 from opposite directions, and the mounting holes 11 and 12 are screwed into female screw portions 15 formed in the chip mounting portion 9 on the opposite side.

In the method of mounting the cutting tool according to this embodiment, first, as shown in FIG. 3, the tool tip 1 is fitted into the tip mounting portion 9 of the tool holder 8. As a result, the tool tip 1
4, a wedge surface formed in a relatively convex V-shape by a step 6 provided on both surfaces on the lower end side and an inverted step 1 of a tip mounting portion 9 of a tool holder 8 as shown in FIG.
The relatively concave V-shaped wedge surfaces formed by 0 abut each other and are positioned. The positions of the tool tip 1 and the tool holder 8 are not stable except on the corresponding wedge surfaces.

Next, as shown in FIG. 5, the tool tip 1 is fixed to the tool holder 8 by the fixing screw 14 and the positioning screw 16. First, the positioning screw 16 that is inserted through the one through hole 4 provided in the tool tip 1 is tightened. At this time, the female screw portion 15 of the mounting hole 12 provided in the tool holder 8
The center line a of the positioning screw 16 and the center line b of the through hole 4 of the tool tip 1 positioned are eccentric to each other, and the center line a of the positioning screw 16 is 0.1 to the shank side of the tool holder 8. It is provided about 0.3 mm away. Therefore, the taper 18 of the head of the positioning screw 16 eccentrically contacts the holder shank side, and the step 6 of the tool tip 1 is contacted.
The tool tip 1 and the tool holder 8 are accurately positioned by exerting a force so that the tool tip 8 is pressed against the wedge surface by the reverse step 10 of the tool holder 8. Next, when the chip fixing screw 14 is tightened, the tool chip 1 is firmly fixed so as to sufficiently withstand the cutting resistance.

In the cutting tool of this embodiment, since the wedge-shaped portions formed by the steps 6 formed on both sides of the tool tip 1 are provided independently of the cutting edge 2, the tool holder 8 shown in FIG. Cutting blade 2 when mounting and positioning and fixing
Since it can be fixed independently of the cutting edge 8 even if the cutting edge 2 is worn or chipped, it does not cause a problem in the mounting accuracy.

Further, in this cutting tool, the tool tip 1 and the tool holder 8 are in principle in contact with each other on the wedge surface, and the tool tip 1
By applying a force to press the wedge against the wedge surface,
Repeated mounting accuracy of the same tip is 10 in peripheral runout value.
13 μm or less, when attaching different chips arbitrarily
It has become possible to reduce it to less than μm. Further, since the cutting edges 2 are formed at both upper and lower end portions of the tool tip 1 and the step 6 is formed rotationally symmetrically on the upper and lower sides, the tool holder 8 can be easily attached and the upper and lower end portions of the tool tip 1 can be easily attached. By using the cutting edge 2, the life of one tool tip 1 can be doubled, and the cost can be significantly reduced.

Further, according to the cutting tool of this embodiment,
Since only the cutting edge 2 of the tool tip 1 can be used as the tool material, it is possible to use a cartridge type tip brazed with diamond, CBN or other tool material, which is very effective in reducing the tool cost. To be

The cutting tool of the present invention is not limited to the shape of the above-mentioned embodiment, but can be appropriately set according to the application, and the step 6 and the reverse step 10 may be convex on either side. It is a good one. Further, the positioning structure between the tool tip and the tool holder can be applied to many cutting tools such as a drill, a counterbore cutter, a chamfering cutter, a ball end mill, and a taper end mill.

[0021]

According to the cutting tool of the present invention, the mounting position of the tool tip and its holder can be stably and firmly positioned with high precision, and the mounting precision does not drop even if it is attached or detached or replaced. It can be anything. Moreover, this tool tip can be formed with cutting edges at both ends, the upper and lower cutting edges can be replaced with the same tool tip, and the life of the tool tip can be extended.
The cost can be reduced by about half.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment (A) and another embodiment (B) of a tool tip of a cutting tool of the present invention.

FIG. 2 is a front view of an embodiment of the tool tip of the cutting tool of the present invention.

FIG. 3 is a front view showing an embodiment of the tool holder of the cutting tool of the present invention.

FIG. 4 is a partially cutaway perspective views (A) and (B) of the tool holder of the embodiment of the cutting tool according to the present invention, showing the tip mounting portion from different directions.

FIG. 5 is a vertical cross-sectional view of the cutting tool of the present invention.

[Explanation of symbols]

 1 Tool Tip 2 Cutting Edge 6 Edge 8 Tool Holder 9 Tip Attachment 9a Tip Attachment Surface 10 Reverse Edge

Claims (5)

[Claims] 1. A cutting tool in which a tool tip for cutting and a tool holder for holding the tool tip are detachably provided, and a step is provided on a surface other than the cutting edge forming portion of the tool tip, A cutting tool, characterized in that a tip mounting surface for holding the tool tip on the tool holder side is also provided with a reverse step that engages with the step to hold the tool tip in the tool holder. 2. The step on the tool tip side is linearly formed on the front and back surfaces of the tool tip so as to be rotationally symmetrical to each other, and the reverse step on the tool holder side is also rotationally symmetrical to each other. The cutting tool described. 3. A tip for holding the tool tip on the tool holder side, wherein the step is formed on each of the front and back planes of the tool tip so as to intersect each other in a V shape on the projection plane. The cutting tool according to claim 1 or 2, wherein the mounting surface is also provided with a reverse step which engages with the gap so as to intersect with each other on the projection surface. 4. The cutting tool according to claim 1, wherein the tool tip has cutting edges formed at both upper and lower ends thereof, and the step is formed corresponding to each of the cutting edges. 5. The upper and lower end portions of each of the upper and lower planes of the tool tip are formed on both front and back planes of the tool tip so as to intersect each other in a V-shape on the projection plane, corresponding to the cutting edges of the both ends. 5. Formed and rotationally symmetrical to each other.
The cutting tool described.