JPH0740035U - Indexable cutting tool - Google Patents

Abstract

(57) [Summary] [Structure] The central axis O parallel to the central axis X of the prepared hole H.
Main cutting edge 1 for machining the inner peripheral surface of the prepared hole H at the tip of the tool body 11 that is revolved around the axis X while being rotated around
The throw-away tip 16 for prepared hole processing provided with 6B is detachably mounted, and at the base end side of the throw-away tip 16 for prepared hole processing, a screw S is provided on the inner peripheral surface of the prepared prepared hole H. A thread processing throw-away tip 17 having a thread cutting edge 17B for forming a thread is detachably attached. [Effect] A pilot hole machined by the pilot hole machining throw-away tip 16 and a thread machining throw-away tip 1
The screw S formed by 7 can be accurately coaxial with each other without eccentricity, and it is possible to easily form a high-precision and high-quality screw hole having a uniform screw over the entire circumference. Further, the pilot hole processing and the screw processing can be performed in one process, and the processing efficiency can be improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention particularly relates to a throw-away type cutting tool used for forming a screw hole.

[0002]

[Prior art]

When forming a relatively large-diameter screw hole in a workpiece, first, as shown in FIG. 2, a throw-away tip having a cutting edge 1 is provided in a prepared hole H formed in a workpiece W by a drill or the like. processing 2 is indexable end mill 3 attached, inserted into the central axis O ₁ direction while rotating the center axis O ₁ about twice the inner circumference of the pilot hole H by the cutting edge 1 to a predetermined diameter To do. Then, as shown in FIG. 3, a threading throw-away type cutting tool 5 equipped with a thread cutting throw-away tip 4 is used, and its central axis O ₂ is the central axis O _{1 of the} above-mentioned throw-away type end mill 3. While being rotated about the central axis O ₂ so as to be coaxial with the position of, the insert is inserted into the prepared hole H processed by the feed according to the pitch of the screw to be formed, and the above-mentioned thread cutting throwaway tip The screw S is formed in the prepared hole H by the cutting blade 6 of 4.

[0003]

[Problems to be solved by the device]

However, in this case, the rotation center axis O ₁ of the indexable end mills 3 of processing the inner periphery of the prepared hole H, between the rotating centric axis O ₂ of the screw machining indexable cutting tool 5 If there is a slight deviation, the screw hole formed in this prepared hole H is eccentric with respect to the prepared hole H machined to a predetermined inner diameter, and it becomes impossible to form a uniform screw S. Specifically, a deep-valley screw S is formed on the side where the central axis O ₂ is eccentric with respect to the central axis O _1, whereas the valley of the screw S is shallow on the opposite side. Will end up. In addition, when the above-described processing method is adopted, the number of processing steps is two, so there is a limit in improving the processing efficiency. Further, in the machining method as shown in FIGS. 2 and 3, the cutting edges 1 and 6 of the throw-away tips 2 and 4 are continuous cutting in which they are always in contact with the inner circumference of the prepared hole H. If the material is such that the chips are easily stretched, the continuously extending chips may become entangled with the throw-away type end mill 3 and the cutting tool 5, hindering smooth machining and damaging the machined surface. Therefore, continuous automatic processing is difficult, and it becomes necessary to provide a chip breaker on the cutting blades 1 and 6.

[0004]

[Means for Solving the Problems]

 The present invention has been made to solve such a problem, and the inner circumference of the prepared hole is formed at the tip of the tool body which is rotated around the central axis while being rotated around the axis parallel to the central axis. The throw-away tip for drilling the surface is detachably attached, and at the base end of this throw-away tip for drilling, a screw is formed on the inner peripheral surface of the drilled hole. The feature is that a throw-away tip for screw processing is attached detachably.

[0005]

[Action]

 In the throw-away cutting tool with such a configuration, one tool body has a throw-away tip for drilling holes on the tip side and a throw-away tip for screw machining on the base end side. First of all, by rotating around the center axis and also around an axis parallel to the center axis, and further inserting the tool body into the prepared hole along the center axis with a feed according to the screw pitch, Use the insert throw-away tip to machine the pilot hole to a specified inner diameter, and then use the thread throw-away tip to form a screw on the inner circumference of the machined pilot hole. That is, the throwaway tip for drilling holes and the throw-away tip for screw machining always rotate integrally around the central axis to cut the pilot hole, so the pilot hole and the screw to be cut by each throwaway tip are screwed. There is no eccentricity with the hole, and it is possible to form a uniform screw over the entire circumference of the prepared hole. Further, since the process of forming the prepared hole to a predetermined inner diameter and the process of forming the screw in the prepared prepared hole can be continuously performed in one process, it is possible to improve the processing efficiency. it can. Furthermore, according to the throw-away type cutting tool of the present invention, the cutting edge is an intermittent cut in which the contact and separation are repeated with respect to the inner circumference of the prepared hole, so that chips are not continuously long and smooth cutting is performed. be able to.

[0006]

【Example】

 FIG. 1 shows an embodiment of the present invention. In this embodiment, the tool body 11 is made of steel or the like and has a substantially columnar shape, and its base end portion is a shank 12 for mounting the tool body on the spindle end of a machine tool such as a machining center. On the other hand, on the outer periphery of the tip of the tool main body 11, a chip pocket 13 is extended in parallel to the central axis O of the tool main body 11, and the tip pocket 13 has a wall surface 13A facing the tool rotation direction. A pair of tip mounting seats 14 and 15 are formed side by side along the central axis O so as to be recessed one step rearward from the wall surface 13A in the tool rotation direction. Among these tip mounting seats 14 and 15, the tip mounting seat 14 located on the tip side of the tool body 11 is opened to the tip surface of the tool body 11, the outer peripheral surface, and the tip pocket 13 and is used as a pilot hole. It is a mounting seat to which the processing throw-away tip 16 is mounted, and the tip end mounting seat 15 on the base end side is opened to the outer peripheral surface of the tool body 11 and the chip pocket 13, and the thread processing throw-away tip 17 is provided. It is used as a mounting seat.

[0007] In the present embodiment, the prepared hole processing throwaway tip 16 mounted on the tip mounting seat 14 on the tip side of the tool body 11 is made of a hard material such as cemented carbide and has a substantially parallelogram flat plate shape. The quadrangular surface is used as a rake surface 16A facing the tool rotating direction, and is attached to the chip mounting seat 14 by means of a clamp screw 18 in a removable manner. A main cutting edge 16B is formed on the long side of the quadrangle formed by the rake face 16A, and a sub cutting edge 16C is formed on the short side so as to be continuous with the main cutting edge 16B. In the throw-away tip 16 for preparing a hole, the main cutting edge 16B is made to project in parallel to the central axis O and slightly outward from the outer peripheral surface of the tip of the tool body 11, and the sub cutting is performed. The blade 16C is fixed by slightly protruding from the tip surface of the tool body 11.

On the other hand, the threading throw-away tip 17 mounted on the tip mounting seat 15 on the base end side of the tool main body 11 is also made of cemented carbide in the present embodiment, similar to the above-mentioned prepared hole throwing-away tip 16. It is formed of a hard material such as, and has a substantially rectangular flat plate shape, and is detachably attached to the chip attachment seat 15 by a clamp screw 19. Here, on the long side portion of the rake face 17A of the thread processing throw-away tip 17, a thread cutting blade 17B having a substantially corrugated shape is formed in accordance with the cross-sectional shape of the screw to be formed. The throw-away tip 17 for screw machining projects this thread cutting edge 17B from the outer peripheral surface of the tip portion of the tool body 11 to the outer peripheral side, and the outer peripheral side of the main cutting edge 16B of the above-mentioned prepared hole machining throw-away tip 16 is provided. It is fixed so that it is located at.

The throw-away cutting tool having such a configuration is such that the center axis O 1 of the tool body 11 is parallel to the center axis X of the prepared hole H and the eccentric distance from the axis X to the center axis O is large. And the radius of gyration of the main cutting edge 16B and the thread cutting edge 17B around the central axis O, the inner diameter (radius) of the inner peripheral machining to be performed on the prepared hole H and the inner diameter (radius) of the screw S to be formed. Is attached to and held by a spindle end of a working machine such as a machining center via the shank 12 so as to be equal to. However, the turning radii around the central axis O of the main cutting edge 16B and the thread cutting edge 17B are set to be smaller than the inner diameter of the prepared hole H.

Then, the tool main body 11 is rotated around its central axis O and revolves around the above-mentioned axis X while being fed in parallel to the central axis O and inserted into the prepared hole H, The prepared hole H is machined by the prepared hole processing throw-away tip 16 and the threaded processing throw-away chip 17. That is, the tool body 11 is fed and inserted into the prepared hole H from the tip side thereof, so that the inner circumference of the prepared hole H 1 is first made to have a predetermined diameter by the main cutting edge 16B of the prepared throw-away insert 16. The threading throw-away tip 17 is inserted into the prepared hole H that has been machined and then machined by the main cutting edge 16B, and the tool main body 11 is fed in accordance with the pitch of the screw S to be formed, thereby cutting the thread. The screw 17 is formed by the blade 17B.

However, according to the throw-away type cutting tool having the above-mentioned structure, the pilot hole machining throw-away tip 16 and the screw machining throw-away tip 17 are mounted on one tool main body 11 and have the same central axis. Since the tool body 11 is integrally rotated around O and revolves around the axis X to form the prepared hole H and the screw S, the main feature of the throw-away tip 16 for prepared hole processing is shown. The rotation center of the cutting edge 16B and the rotation center of the thread cutting edge 17B of the thread cutting insert 17 do not deviate from each other, and therefore the thread cutting is performed with respect to the inner diameter of the prepared hole H machined by the main cutting edge 16B. The inner diameter of the screw S formed by the cutting blade 17B does not decenter. That is, since the screw S is coaxially and accurately formed with respect to the prepared hole H machined to a predetermined diameter by the prepared hole processing throw-away tip 16, the valley on one side of the screw hole is different from the conventional one. It is possible to prevent a situation where a deep screw is formed or the valley of the screw becomes shallower on the opposite side, and it is easy to make a uniform screw S over the entire circumference of the screw hole. Since it can be formed, it is possible to perform screw processing with high precision and quality.

Further, conventionally, a step of inserting a throw-away type end mill for processing a prepared hole to process the prepared hole H to a predetermined inner diameter, and a step of extracting the throw-away type end mill from the prepared hole H In contrast to the two steps of inserting the throw-away type cutting tool for threading into the prepared hole H and performing thread cutting, the slow-away type cutting tool of the above configuration By rotating (spinning) the main body 11 about the central axis O and revolving about the axis X and inserting the main body 11 into the prepared hole H, the inner diameter processing of the prepared hole H and the formation of the screw S are continuously performed in one step. Can be done. Therefore, it is possible to reduce the number of steps, reduce the time and labor required for tool exchange and alignment between steps, and significantly improve the machining efficiency.

Further, in the present embodiment, as described above, the tool body 11 is rotated about its central axis O and revolves around the above-mentioned axis X, so that the throwaway chips 16 and 17 are turned off. Intermittent cutting is performed in which the blades 16B and 17B perform cutting while repeating contact and separation with respect to the inner circumference of the prepared hole H of the workpiece W. Therefore, even if the material of the workpiece W is such that the chips are relatively liable to grow, the chips are always divided into a certain length to be generated and the chip disposability is improved. According to this, such chips do not get entangled with the tool body 11 or damage the machined surface, and continuous automatic machining can be easily performed. Further, it is not necessary to provide a chip breaker on the cutting blades 16B and 17B. In this embodiment, the tool body 11 is equipped with the pair of prepared hole processing throw-away tips 16 and the screw processing throw-away tips 17, but, for example, even if a plurality of at least one of these is mounted. Good. Further, in the present embodiment, both throw-away tips 16 and 17 are mounted in one tip pocket 13 so as to be aligned in the direction of the central axis O. However, a plurality of tip pockets are formed in the tool main body 11 to form a prepared hole in each. A processing throw-away tip or a thread processing throw-away tip may be attached.

[0014]

[Effect of device]

 As described above, according to the present invention, the eccentricity of the prepared hole processed by the prepared hole processing insert and the screw formed by the threaded processing insert into the prepared prepared hole are eccentric. It is possible to form the coaxial accurately without doing so, and thus it becomes possible to easily form a highly accurate and high-quality screw hole having a uniform screw over the entire circumference. In addition, it is possible to perform high-precision screw machining in a single process in this way, and it is possible to greatly improve machining efficiency, while improving chip disposability and facilitating continuous automatic machining, etc. It can be possible.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view of a throw-away type end mill 3 used for conventional pilot hole machining.

FIG. 3 is a side view of a throw-away type cutting tool 6 used for conventional thread processing.

[Explanation of symbols]

 11 Tool Main Body 13 Chip Pocket 14, 15 Chip Mounting Seat 16 Throw-away Tip for Pilot Hole Processing 16B Main Cutting Edge 17 Throw-away Tip for Screw Machining 17B Cutting Edge for Thread W Workpiece H Pilot Hole S Screw O Tool Body 11 Center axis X Center axis of pilot hole H

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Baemi Ito, Kobe Town, Anha-gun, Gifu 1528 Nakanishi, Yokoi, Kyoto, Japan Mitsubishi Materials Corporation Gifu Factory (72) Inventor Yoshihisa Yano Kobe Town, Anha-gun, Gifu Prefecture Daiji Yokoi Nakasita 1528 Address Mitsubishi Materials Corporation Gifu Factory

Claims (1)

[Scope of utility model registration request] 1. A throw-away tip for drilling a hole for processing an inner peripheral surface of a pilot hole is attached to and detached from a tip of a tool body which is rotated around a central axis while being rotated around the central axis. In addition to being freely installed, a thread processing throw-away tip that forms a screw on the inner peripheral surface of the processed pilot hole is detachably attached to the base end side of this pilot hole processing throw-away tip. A throw-away type cutting tool characterized by having.