JPH0717401U - Cutting tools - Google Patents

Abstract

(57) [Summary] [Structure] A tip mounting seat 4 is formed at the tip of the shank 1, and a throw-away tip 5 is detachably mounted. The throw-away tip 5 is attached to the tip mounting seat 4.
Mounting seat bottom surface 4A to which the lower surface 5C of the mounting seat wall 4B closely contacts, and a mounting seat wall surface 4B on which the peripheral surface 5B of the throw-away tip 5 abuts against the mounting seat bottom surface 4A, and this mounting seat wall surface 4B.
Of the mounting seat bottom surface 4A side of the escape portion 4 provided along the edge
C and are provided. Further, the shank 1 is provided with a cutting oil supply hole 8 from the base end side toward the tip end, and the tip end of the supply hole 8 is opened in the tip mounting seat 4 and communicated with the escape portion 4C. There is. [Effect] The cutting fluid can be concentratedly supplied to the cutting portion to reduce the cutting resistance and efficiently cool the cutting portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cutting tool such as a boring bar used for the inner circumference machining of a prepared hole formed in a work material.

[0002]

[Prior art]

 In this type of boring bar, a chip pocket is formed on the head at the tip of a cylindrical shaft-shaped shank made of steel or cemented carbide, and at the intersection of the bottom of this chip pocket and the head tip surface and outer peripheral surface. It is known that a cutting blade is provided on the formed mounting seat by, for example, detachably attaching a throw-away tip. The head may be molded integrally with the shank, or may be removable from the shank. In such a boring bar, the base end of the shank is attached to and held by a holding table of the machine tool, and the head is inserted into the prepared hole of the work material that is also rotatably supported by the machine tool. Then, the inner peripheral surface of the prepared hole is cut by the cutting blade provided in the head.

[0003]

[Problems to be solved by the device]

 By the way, not only in the inner circumference machining of the prepared hole using such a boring bar, but also in the cutting machining with a cutting tool, the friction between the work material and chips generated during cutting and the tool is reduced to reduce the cutting resistance. In general, in order to prevent the decrease in hardness of the cutting edge by taking away the heat generated by this friction, the cutting oil is generally supplied while working.

Particularly in the inner circumference machining of the prepared hole by the boring bar, the protrusion amount of the shank from the tool post is often relatively long, so that the cutting resistance acting on the cutting blade causes the shank to run out. Since chattering easily causes deterioration of machining accuracy, etc., and the heat generated during cutting is easily trapped in the prepared hole and the temperature of the cutting part easily becomes high. The supply of oil is an essential and indispensable factor. However, in such inner circumference machining, the cutting part is located inside the pilot hole, so it is not always easy to supply the oil agent, and it is necessary to simply feed the oil agent into the pilot hole. It is difficult to efficiently and evenly deliver the cutting fluid only to a large cutting area, and thus it is inevitable that the use of the cutting fluid becomes inefficient.

The present invention has been made in view of such circumstances, and an object of the present invention is to supply cutting fluid intensively around the cutting portion in the inner circumference of the prepared hole to reduce cutting resistance. It is intended to provide a cutting tool capable of effectively cooling a cutting portion.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention has a chip mounting seat formed on the bottom of a chip pocket formed at the tip of a shaft-like shank so as to be recessed from the bottom, and a flat throwaway member is mounted on the chip mounting seat. In a cutting tool in which a tip is removably mounted, a bottom surface of the attachment seat where the lower surface of the throw-away tip is closely attached to the tip attachment seat, and a circumference of the throw-away tip that stands upright with respect to the bottom surface of the attachment seat. Surface is in contact with the mounting seat wall surface, and is provided along the edge of the mounting seat wall surface on the bottom surface side of the mounting seat to prevent interference between the lower part of the peripheral surface of the throw-away tip and the tip mounting seat. The shank is provided with a cutting oil supply hole from the base end side in the axial direction toward the tip, and the tip of this supply hole is opened in the tip mounting seat. Shimete wherein the communicating with the relief portion.

[0007]

[Action]

 In the cutting tool having such a configuration, the cutting fluid is supplied to the tip side through the supply hole formed in the shank and is ejected from the opening of the supply hole formed in the tip mounting seat. Here, the throw-away tip is mounted on this tip mounting seat, but at the same time, the tip mounting seat has a relief part formed at the lower part of the wall surface of the mounting seat, and the supply hole is connected to this relief part. Therefore, the supplied cutting fluid passes through this relief part and squirts from the opening of the relief part outside the shank. However, this relief is formed along the wall surface of the mounting seat against which the peripheral surface of the throw-away tip comes into contact, and the opening on the outside of the shank of the relief is also formed adjacent to the throw-away tip. The cutting fluid can be efficiently supplied to the cutting site and effective cooling can be achieved.

Here, the throw-away tip is formed in a polygonal flat plate shape, and the tip mounting seat is provided with a plurality of mounting seat wall surfaces and relief portions, and a cutting fluid supply hole is formed in these mounting seat wall surfaces. The cutting fluid supplied to the tip passes through the above-mentioned multiple relief parts by opening the hollow part formed at the intersection and communicating with the above-mentioned relief parts. Since it is jetted out substantially evenly from the opening on the outside of the shank adjacent to, the oil agent can be supplied to the cutting site more efficiently. In addition, a groove is formed along the intersection of the bottom surface of the mounting seat and the relief to increase the amount of oil supplied to the cutting site and improve the cooling effect. Can be planned.

[0009]

【Example】

 1 and 2 show the tip of a boring bar which is an embodiment of the present invention. In these drawings, the shank 1 has a substantially cylindrical outer shape, and its tip portion is slightly enlarged in diameter to form a head 2. A tip pocket 3 is formed on the head 2 so as to open to the tip end surface and the outer peripheral surface thereof, and the bottom surface 3A of the tip pocket 3 is further recessed from the bottom surface 3A by one step, and the tip end surface of the head 2 is formed. Also, a chip mounting seat 4 that opens to the outer peripheral surface is formed. A throw-away tip 5 made of a hard material such as cemented carbide is attached to the tip mounting seat 4 so that the cutting edge 6 thereof projects toward the tip side and the outer peripheral side of the head 2 and is detachably mounted. It is fixed by screws 7.

Here, in the present embodiment, the throw-away chip 5 mounted on the tip mounting seat 4 has a substantially equilateral triangular flat plate shape in a plan view, and the upper surface 5A thereof is a rake surface, Further, the three peripheral surfaces 5B ... Are flanks, and the cutting edge 6 is formed on the ridge line portion where these peripheral surfaces 5B ... And the upper surface 5A intersect. The lower surface 5C is a seating surface for the tip mounting seat 4. On the other hand, the tip mounting seat 4 is formed as a recess conforming to the shape of the throw-away tip 5, and the mounting seat bottom surface 4A to which the lower surface 5C closely contacts and a pair of standing upright with respect to the mounting seat bottom surface 4A. It is defined by the mounting seat wall surfaces 4B and 4B. Further, the lower edge portions of the mounting seat wall surfaces 4B, 4B on the side of the mounting seat bottom surface 4A are provided with escape portions 4C, 4C retracting with respect to the mounting seat wall surfaces 4B, 4B. .. and the lower surface 5C of the peripheral surface 5B do not interfere with the chip mounting seat 4. Therefore, these escape portions 4C, 4C are arranged outside the peripheral surfaces 5B, 5B along the peripheral surfaces 5B, 5B when the throw-away tip 5 is mounted. Further, at a crossing portion between the pair of mounting seat wall surfaces 4B, 4B, a notch portion 4D for preventing interference between the crossing portion between the peripheral surfaces 5B of the throw-away tip 5 and the tip mounting seat 4 is formed. Has been done.

On the other hand, the shank 1 is provided with a cutting oil supply hole 8 along the central axis O from the base end side of the shank 1 toward the head 2 at the tip. Then, the tip of the supply hole 8 extends into the head 2 and opens to the one mounting seat wall surface 4B of the chip mounting seat 4, and to the escape portion 4C at the lower edge of the one mounting seat wall surface 4B. It is in communication. Here, since the tip mounting seat 4 is formed so as to open to the tip end surface and the outer peripheral surface of the head 2 as described above, the relief portions 4C and 4C of the tip mounting seat 4 have one end of the head 2 at each end. It is formed so as to open to the tip surface and the outer peripheral surface. Moreover, since these relief portions 4C, 4C are arranged along the peripheral surfaces 5B, 5B of the throw-away tip 5, their openings are also adjacent to the throw-away tip 5 and face the cutting edge 6. Will be installed.

In the boring bar having such a structure, as described above, the base end of the shank 1 is attached to and held by a holding stand of a machine tool, and the work piece is also rotatably supported by the machine tool. The head 2 is inserted into the prepared hole of the material, and the inner peripheral surface of the prepared hole is cut by the cutting blade 6. Here, a supply pipe for the cutting fluid attached to the machine tool is connected to the shank 1 base end side of the supply hole 8, and the cutting fluid is supplied with a supply pressure from the machine tool side during cutting. Are supplied to the supply hole 8. The cutting fluid thus sent to the supply hole 8 is sent to the tip side of the shank 1 through the supply hole 8 and flows into the escape portions 4C, 4C of the tip mounting seat 4, and It flows along the escape portions 4C, 4C, and jets from the openings of the tip surface and the outer peripheral surface of each head 2. However, since these openings are arranged so as to face the cutting edge 6 adjacent to the throw-away tip 5 as described above, according to the boring bar having the above-mentioned configuration, the cutting oil can be removed by the cutting edge 6. It can be sprayed intensively on and near the cutting site of the work material.

As described above, according to the boring bar having the above-described configuration, in the inner peripheral machining of the prepared hole formed in the work material, the oil agent can be easily supplied to the cutting site even during the cutting machining, whereby the cutting resistance And the cutting portion of the work material and the cutting edge 6 can be cooled. Moreover, as described above, since the cutting fluid is sprayed intensively on the cutting site by the cutting edge 6, the cutting fluid can be used efficiently and the resistance can be reduced more effectively. It becomes possible to cool the cutting site. As a result, it is possible to suppress the runout and chatter of the shank 1 and maintain the machining accuracy, and to quickly remove the heat generated during cutting and prevent this heat from trapping in the prepared hole. It is possible to perform stable cutting. In addition, according to the boring bar having the above-described configuration, the cutting oil supply hole 8 does not directly open to the outside of the head 2, so that the supply hole 8 is blocked by, for example, chips or the like, so that the oil supply can be performed. There is also an advantage that a stable supply of cutting fluid can be always provided without any hindrance.

Next, FIGS. 3 and 4 show another embodiment of the present invention. The same parts as those of the embodiment shown in FIGS. Omit it. In the embodiments shown in these figures, the cutting oil supply hole 8 extending to the head 2 is opened in the recessed portion 4D formed at the intersection of the pair of mounting seat wall surfaces 4B, 4B of the chip mounting seat 4. And is communicated with each of the relief portions 4C, 4C, and a recessed groove 10 having a substantially circular cross section is formed in each of the relief portions 4C, 4C along a line intersecting with the mounting seat bottom surface 4A. It is characterized by that.

Even in the boring bar having such a structure, however, the openings of the escape portions 4C, 4C on the outer side of the head 2 are arranged so as to be adjacent to the throw-away tip 5 and face the cutting edge 6. It is possible to spray the cutting oil intensively on the cutting site of the work material by the cutting edge 6 and its vicinity, and efficiently supply the cutting oil to effectively reduce the resistance and cool the cutting site. It will be possible. Further, in the present embodiment, the supply hole 8 is opened in the recessed portion 4D at the intersection of the pair of mounting seat wall surfaces 4B, 4B, and both of the relief portions 4C, 4C at the lower edges of these mounting seat wall surfaces 4B, 4B are provided. Since they are communicated with each other, the cutting oil can be supplied substantially evenly to both of the relief portions 4C and 4C and ejected from the opening, and the cutting oil can be supplied more efficiently. Is obtained. Further, in this embodiment, since the recessed groove 10 is formed in the relief portion 4C, the cross-sectional area of the cutting oil supply path from the supply hole 8 to the opening on the outside of the head 2 is enlarged to increase the cutting oil It is possible to increase the supply amount, thereby reducing the cutting resistance and further improving the effect of cooling the cut portion.

In each of the above-mentioned two embodiments, the case where the present invention is applied to the boring bar used for the inner circumference machining of the prepared hole has been described. However, other cutting tools, for example, a throw-away type bite, etc. May be used for. Further, in the above embodiment, the throwaway chip 5 is a positive throwaway chip, but it is of course possible to apply the present invention when using a negative throwaway chip.

[0017]

[Effect of device]

 As described above, according to the present invention, it becomes possible to intensively supply the cutting fluid to the cutting site located inside the pilot hole in the inner circumference machining of the pilot hole by the boring bar, etc. While improving efficiency, it is possible to reduce cutting resistance and effectively cool the cutting site, and maintain stable machining while enabling stable cutting.

[Brief description of drawings]

FIG. 1 is a plan view of a head 2 at the tip of a boring bar showing an embodiment of the present invention.

FIG. 2 is a YY sectional view of the embodiment shown in FIG.

FIG. 3 is a plan view of a head 2 at the tip of a boring bar showing another embodiment of the present invention.

FIG. 4 is a ZZ sectional view of the embodiment shown in FIG.

[Explanation of symbols]

 1 shank 2 head 3 chip pocket 3A chip pocket bottom 4 chip mounting seat 4A mounting seat bottom 4B mounting seat wall surface 4C relief 4D recessed portion 5 throwaway tip 5B throwaway tip 5 peripheral surface 5C throwaway tip 5 bottom surface 6 cut Blade 8 Supply hole 10 Recessed groove

Continued Front Page (72) Hiroyuki Takahashi 1511 Furumagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works

Claims (3)

[Scope of utility model registration request] 1. A tip mounting seat is formed on the bottom surface of a tip pocket formed at the tip of an axial shank so as to be recessed from the bottom surface, and a flat throwaway tip is detachably mounted on the tip mounting seat. In the cutting tool, the tip mounting seat has a mounting seat bottom surface to which the lower surface of the throw-away tip is in close contact, and a mounting seat wall surface against which the peripheral surface of the throw-away tip comes into contact. , A clearance portion provided along an edge portion of the mounting seat wall surface on the side of the mounting seat bottom surface and a relief portion for avoiding interference between the lower portion of the peripheral surface of the throw-away tip and the tip mounting seat, Further, the shank is provided with a cutting oil supply hole from the base end side in the axial direction toward the tip, and the tip of the supply hole is opened in the tip mounting seat to allow the escape. A cutting tool that is in communication with the barb. 2. The throw-away tip is formed in a polygonal flat plate shape, and the tip mounting seat is provided with a plurality of the mounting seat wall surfaces and escape portions. The cutting tool according to claim 1, wherein the cutting tool has an opening in a recessed portion of a wall surface of the mounting seat and is communicated with the relief portion. 3. The groove according to claim 1 or 2, wherein a groove is formed along the line of intersection between the bottom surface of the mounting seat and the relief. Cutting tools.