JP2005186224A - Throw-away drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away drill, having excellent workability and cost performance in replacing a throw-away tip, and preventing lowering of strength even in the case of a small-diameter type. <P>SOLUTION: In this throw-away drill 1, a substantially plate-like throw-away tip 3 is removably held and fixed in a recessed part 6 of the forward end of a holder 2 having a rotating shaft in common to the throw-away tip 3. In the holder 2, the inner wall of the forward end recessed part 6 has two clamping wall surfaces 4 opposite to each other and inclined to gradually decrease in spacing as they go toward the forward end of the holder 2. The throw-away tip 3 includes two cutting blades 11 at the forward end; and two clamped wall surfaces abutting on the clamping wall surfaces 3 at the main surface part, wherein the forward end space Y<SB>s</SB>of the clamped wall surface 5 is larger than the forward end space X<SB>s</SB>of the clamping wall surfaces 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a throw-away drill in which a throw-away tip having a rotation axis common to a holder tool main body is detachably mounted.

  Conventionally, as a throw-away drill in which a throw-away tip having a rotation axis common to the holder tool body is detachably mounted, a flat throw-away tip is sandwiched at the tip of the holder, and the side surface of the holder is fastened with screws. The configuration is generally known (for example, see Patent Document 1).

Further, there is also known a configuration in which a screw structure is provided on the holder and the throw-away tip itself as disclosed in Patent Document 2 and these are connected and fixed to each other.
Japanese translation of PCT publication No. 2002-522233 Special table 2003-505261

  However, in the configuration disclosed in Patent Document 1, a through-hole for passing a screw through the throw-away tip must be provided, and particularly when the throw-away tip is used with a small-diameter throw-away drill, There was a problem that the strength was insufficient and it was easily damaged. In addition, since a screw is used, there is a disadvantage that the replacement work of the throw-away tip becomes complicated.

  On the other hand, the configuration disclosed in Patent Document 2 does not have the above-described problem, but the shape of the holder and the throw-away tip becomes extremely complicated, and thus there is a problem that the manufacturing cost is remarkably increased. It was.

  The present invention has been made in order to solve such a problem of the prior art, and in a throw-away drill in which a throw-away tip having a coaxial rotation shaft common to a holder is detachably mounted, the throw-away tip is replaced. It is an object of the present invention to provide a throw-away drill that is excellent in workability and cost performance, and that does not decrease in strength even if it is a small diameter type.

  In order to solve the above-mentioned problem, the throw-away drill according to claim 1 is a throw in which a substantially plate-shaped throw-away tip is detachably clamped and fixed in a tip recess of a holder having a rotation axis common to the throw-away tip. In the away drill, the holder includes two holding wall surfaces that are opposed to each other and inclined so that a surface interval gradually decreases toward the holder tip side, on the inner wall of the tip recess, The tip includes two cutting edges at positions symmetrical to the rotation axis of the tip portion, and two sandwiched wall surfaces that contact the sandwich wall surface at the main side surface portion, and the tip of the sandwich wall surface It is characterized in that the tip end interval of the sandwiched wall surface is larger than the interval.

  According to such a configuration, since the throw-away tip is inserted and attached to the recessed portion at the tip so as to spread the two sandwiched wall surfaces, the sandwiched wall surface presses the sandwiched wall surface by the elastic force of the holder as a reaction. Although the throw-away tip is clamped and fixed in the recess at the tip of the holder, no screw is used to mount the throw-away tip, so the throw-away tip can be used without reducing the strength of the throw-away tip, especially in small-diameter types. Workability at the time of replacement can be improved. In addition, since both the holder and the throw-away tip have a relatively simple structure, the manufacturing cost can be reduced.

  The throw-away drill according to claim 2 is characterized in that a positioning member for the throw-away tip is provided in the tip recess.

  According to such a configuration, since the center position of the throw-away tip can be easily determined, the workability at the time of replacing the throw-away tip can be improved, and the accuracy of the machining hole can also be improved.

  The throw-away drill according to claim 3 is characterized in that at least a part of a bottom surface of the tip recess is a sliding inclined bottom surface that is inclined from one side to the other side of the sandwich wall surface.

  According to such a configuration, the rear end side shape of the throw-away tip is configured to engage with the sliding inclined bottom surface, so that the throw-away tip can be smoothly inserted into the tip recess of the holder using the sliding inclined bottom surface as a guide. Therefore, the workability when the throw-away tip is mounted can be improved.

  The throw-away drill according to claim 4 is characterized in that at least one step is provided on the bottom surface of the tip recess portion from one side to the other side of the clamping wall surface.

  According to this configuration, the rear end side shape of the throw-away tip is shaped to engage with the step portion, so that the throw-away tip can be smoothly inserted into the tip recess of the holder using the step portion as a guide. Therefore, the workability when the throw-away tip is attached can be improved.

  According to the throw-away drill of the present invention, a generally plate-shaped throw-away tip is a throw-away drill that is detachably sandwiched and fixed to a tip recess of a holder having a rotation shaft common to the throw-away tip, The holder includes two sandwiching wall surfaces that are opposed to each other on the inner wall of the tip recess and are inclined so that a surface interval gradually decreases toward the holder tip side. Two cutting blades at positions symmetrical to the rotation axis, and two sandwiched wall surfaces in contact with the sandwiching wall surface at the main side surface portion, and the sandwiched portion is more than the tip interval of the sandwiching wall surface. The throwaway tip is inserted and installed in the tip recess so as to spread the two sandwiching walls by adopting a configuration in which the tip end of the wall is larger. As a reaction, the clamping wall surface presses the sandwiched wall surface due to the elastic force of the holder, and as a result, the throw-away tip is clamped and fixed in the recess at the tip of the holder, but no screw is used to mount the throw-away tip. Especially in the small-diameter type, it is possible to improve the workability when replacing the throw-away tip without reducing the strength of the throw-away tip, and the holder and the throw-away tip are relatively simple. Cost reduction during manufacturing can be achieved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 7 show an embodiment of the present invention. FIG. 1 is a perspective view of a tip portion of a throw-away drill (hereinafter abbreviated as a drill) according to a first embodiment of the present invention, and FIG. 1 is a side view of the tool holder in FIG. 1, FIG. 3 is a perspective view showing a state in which the throw-away tip (hereinafter abbreviated as a tip) 3 in FIG. 1 is being mounted, FIG. 4 is a front view of FIG. FIG. 6 to FIG. 9 are side views of the tip of a drill according to another embodiment of the present invention.

  In FIG. 1, the drill 1 by 1st embodiment of this invention becomes a structure by which the chip | tip 3 was attached to the front-end | tip part of the holder 2 so that attachment or detachment was possible. First, as a configuration of the holder 2, as shown in FIG. 2, a tip recess 6 having two sandwiching wall surfaces 4 facing each other is formed at the tip of the holder 2. Here, the sandwiching wall surface 4 is inclined so that the surface interval X gradually decreases toward the tip end side of the holder 2. The tip 2 has a substantially plate shape with two cutting edges 11 at the tip, and has a sandwiched wall surface 5 in contact with the sandwich wall surface 4 on its main side surface, and the sandwiched wall surface. 5 inclines so that chip | tip thickness (clamping surface space | interval) Y becomes small as it goes to a front end side from a rear end side.

Then, as shown in FIG. 3, the chip 3 to the tip recess 6, is inserted between the sides thereof of the two clamping walls 4, tip spacing X _S of the clamping wall 4 the of the tip 3 to be Since the tip interval Y _S (tip tip thickness) of the sandwiching wall surface 5 is smaller, the tip 3 is mounted so as to spread the two sandwiching wall surfaces 4 of the tip recess 6 as shown in FIG. The two sandwiched wall surfaces 5 of the chip 3 are pressed and fixed by the elastic force P of the holder 2. At this time, as described above, the sandwiching wall surface 4 is inclined so that the surface interval X becomes smaller toward the front end side of the holder 2, so that the tip 3 is caused by the component force of the elastic force P toward the holder rear end direction. It will be in the state pressed to the bottom face side of the front-end | tip recessed part 6. FIG. As a result, the drill 1 in which the tip 3 is firmly fixed to the tip recess 6 of the holder 2 can be obtained.

  Incidentally, when the chip 3 is inserted into the tip recess 6, the portion of the chip 3 that is first applied to the holder 2, that is, the edge portion 12 on the side of the sandwiched wall surface 5 that is inserted into the tip recess 6 performs smooth insertion. It is also effective to chamfer (not shown) such as a chamfer surface.

  In addition, since the drill 1 in this embodiment does not use a screw for mounting the tip 3 to the holder 2, especially in a small-diameter type drill, the workability at the time of tip replacement is reduced without reducing the strength of the tip 3. A good drill can be obtained. In addition, since both the holder 2 and the chip 3 have a relatively simple structure, the manufacturing cost can be reduced.

  Further, in the present embodiment, a locking portion 7 as a positioning member for the chip 3 is provided on the bottom surface of the tip recess 6, and a notch portion 8 is provided on the rear end side of the chip 3 to engage with the locking portion 7. Was provided. As a result, the center position of the chip 3 can be easily determined, so that the workability at the time of chip replacement can be improved and the accuracy of the processing hole can be improved. Incidentally, the positioning member is not limited to the configuration as in the present embodiment. For example, a component such as a commercially available spring plunger (not shown) is embedded in the bottom surface of the tip recess 6 of the holder 2 to insert the chip 3. It is also possible to adopt a configuration in which a recess that engages with the spring plunger is provided on the rear end face side.

  When the chip 3 is inserted into the tip recess 6 of the holder 2, a force pressed by each sandwiched wall surface 4 acts on the two sandwiched wall surfaces 5. In such a state, as shown in FIG. 4, the tip 3 is pushed into the tip recess 6 of the holder 2 while being inclined, so that the smooth mounting of the tip 3 is hindered and the sandwiching wall surface 4 of the holder 2 is damaged. There is a tendency to wear it. Here, as shown in FIG. 6, a part of the bottom surface of the tip recess 6 is provided with a sliding inclined bottom surface 9 that is inclined from one side to the other side of the clamping wall surface, and the bottom shape of the chip 3 is also the sliding shape. Since the chip 3 can be inserted using the sliding inclined bottom surface 9 as a guide by making the shape so as to contact the inclined bottom surface 9, the chip 3 is not inserted while being inclined and the chip 3 is mounted. Can be performed smoothly, and the life of the holder 2 can be extended. Incidentally, FIG. 7 shows another embodiment using the sliding inclined bottom surface 9.

  As another form as a guide when the chip 3 is inserted into the tip recess 6 of the holder 2, a step 10 may be provided on a part of the bottom surface of the tip recess 6 as shown in FIG. 8. As a result, the tip 3 is inserted with the stepped portion 10 as a guide, similarly to the sliding inclined bottom surface 9 described above, so that the tip 3 can be mounted smoothly without being inserted with the tip 3 tilted. In addition, the life of the holder can be extended. Incidentally, FIG. 9 shows another embodiment using the stepped portion 10.

  As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to the said embodiment, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the objective of invention.

It is a front-end | tip part perspective view of the throw away drill by 1st embodiment of this invention. It is a side view of the holder of FIG. It is a perspective view which shows the state in the middle of attachment of the throw away tip of FIG. FIG. 4 is a front view of FIG. 3. It is sectional drawing in the throwaway tip mounting state of FIG. It is a front-end | tip part side view of the throw away drill by other embodiment of this invention. It is a front-end | tip part side view of the throw away drill by other embodiment of this invention. It is a front-end | tip part side view of the throw away drill by other embodiment of this invention. It is a front-end | tip part side view of the throw away drill by other embodiment of this invention.

Explanation of symbols

1 Throw away drill (drill)
2 Holder 3 Throw away tip (chip)
4 clamping walls 5 clamped wall 6 tip recess 7 the locking portion 8 notch 9 sliding inclined bottom surface 10 step portion 11 cutting 12 edge portion X clamping wall surface interval _{X S} nipped wall of the tip distance Y chip thickness (clamped Wall spacing)
Tip spacing between the Y _S sandwiched wall surfaces (tip thickness at tip tip side)

Claims (4)

A throw-away drill in which a substantially plate-shaped throw-away tip is detachably sandwiched and fixed to a tip recess of a holder having a rotation axis common to the throw-away tip, and the holder is attached to an inner wall of the tip recess. Two sandwiching wall surfaces that face each other and incline so that the surface interval gradually decreases toward the front end side of the holder, and the throw-away tip is positioned symmetrically with respect to the rotation axis of the front end portion. Two cutting edges and two sandwiched wall surfaces that contact the sandwich wall surface on the main side surface portion, and the tip spacing of the sandwiched wall surface is larger than the tip spacing of the sandwich wall surface Characteristic throw-away drill. The throw-away drill according to claim 1, wherein a positioning member for the throw-away tip is provided in the tip recess. The throw-away drill according to claim 1 or 2, wherein at least a part of the bottom surface of the tip recess is a sliding inclined bottom surface that is inclined from one side to the other side of the clamping wall surface. The throw-away drill according to claim 1 or 2, wherein at least one step portion is provided on a bottom surface of the tip concave portion from one side to the other side of the clamping wall surface.

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