JP2012179685A - Head exchange type cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head exchange type cutting tool in which a cutting head and a holder can be accurately and simply centered without making a manufacturing process complicated.SOLUTION: The head exchange type cutting tool includes: a cutting head 2 having a cutting edge; a holder 3 on which the cutting head 2 is attachably/detachably mounted; and a pin member 4 which fixes the cutting head 2 onto the holder 3 by screwing. The cutting tool is characterized in that the holder 3 is provided with a cylinder part 5 which is made coaxial with the center axis C1 of the holder 3 and which is elastically deformable outward in the radial direction perpendicular to the center axis C1, that the cutting head 2 is arranged outward in the radial direction of the cylinder part 5 and is provided with a contact part 8C on which the cylinder part 5 can be abutted, and that the pin member 4 is provided with an expanding part 4C which comes into contact with the cylinder part 5 internally in the radial direction to elastically deform the cylinder part 5 outwardly in the radial direction.

Description

  The present invention relates to a head exchangeable cutting tool.

  Conventionally, as this type of head-exchangeable cutting tool, for example, as shown in Patent Document 1 below, a replacement blade (cutting head) having a cylindrical shape and having a cutting edge on its outer peripheral surface, and a shaft-shaped tip portion thereof. A shank (holder) on which a replacement blade is detachably mounted and a mounting screw (pin member) for fixing the replacement blade to the shank by screwing is known.

  In the head replaceable cutting tool of Patent Document 1, the fitting shaft provided on the mounting screw is fitted into the fitting hole provided in the exchange blade and the fitting hole provided in the shank. The replacement blade and the shank are positioned coaxially (concentrically) via the fitting shaft portion.

JP 2007-167777 A

However, the conventional head exchangeable cutting tool has the following problems.
That is, in order to accurately and coaxially position the cutting head and the holder, it is necessary to polish the fitting portion of the pin member (the fitting shaft portion), the fitting hole of the cutting head, and the fitting hole of the holder with high accuracy. The manufacturing process was complicated. In particular, the cutting head is made of a hard cemented carbide or the like, and is difficult to polish.

  The present invention has been made in view of such circumstances, and provides a head replaceable cutting tool capable of accurately and easily aligning a cutting head and a holder without complicating the manufacturing process. It is aimed.

In order to achieve the above object, the present invention proposes the following means.
That is, the present invention provides a head replacement comprising a cutting head having a cutting edge, a holder to which the cutting head is detachably mounted, and a pin member for fixing the cutting head to the holder by screwing. The holder is coaxial with a central axis of the holder, and has a cylindrical portion that is elastically deformable outward in a radial direction perpendicular to the central axis. The cylindrical portion has an abutting portion that is disposed on the outer side in the radial direction and on which the cylindrical portion can abut, and the pin member abuts on the cylindrical portion from the inner side in the radial direction. It has a push-expansion part which elastically deforms toward the outward of the radial direction.

The head exchangeable cutting tool of the present invention has the following effects.
That is, when the cutting head is mounted on the holder, the expanded portion of the pin member abuts against the cylindrical portion of the holder from the inside in the radial direction and elastically deforms the cylindrical portion toward the outside in the radial direction. , Expand. Thereby, the central axis of the pin member and the central axis of the holder are positioned coaxially.
Furthermore, the elastically deformed cylinder part comes into contact with the contact part of the cutting head located outward in the radial direction. Thereby, the central axis of the holder and the central axis of the cutting head are positioned coaxially.

  In this way, the cylindrical portion of the holder is elastically deformed and brought into contact with the contact portion of the cutting head, so that the centering (centering) between the holder and the cutting head is performed. Unlike centering, according to the head replaceable cutting tool of the present invention, high-precision polishing is not required for the cylindrical portion, the abutting portion, and the expanded portion. Specifically, according to the head exchangeable cutting tool, only rough polishing or no polishing can be performed with respect to the cylindrical portion, the abutting portion, and the expanded portion. In particular, it is excellent in that polishing is unnecessary for a cutting head made of a hard cemented carbide or the like, and the state after sintering can be used for cutting as it is.

  Therefore, according to the present invention, the cutting head and the holder can be aligned accurately and easily without complicating the manufacturing process.

  In the head exchangeable cutting tool of the present invention, the cylindrical portion may have a plurality of wall portions formed so as to be divided along a circumferential direction around the central axis of the holder.

  In this case, since the cylindrical portion has a plurality of wall portions formed so as to be divided in the circumferential direction, when the pin member pushes the cylindrical portion outward in the radial direction, the cylindrical portion The part is more likely to be elastically deformed, and more easily contact the contact part. Therefore, the above-described operational effects can be obtained stably.

  Further, in the head replaceable cutting tool of the present invention, the expanding portion is gradually outward in the radial direction as it is separated from a screw portion formed at one end of the pin member and screwed into the holder toward the other end. It is good also as having a taper surface which inclines toward the direction.

  In this case, since it becomes easy to insert the pin member into the tube portion and the tube portion is elastically deformed so as to be inclined with respect to the central axis of the holder, the tube portion and the contact portion are more likely to contact each other. Become.

  Further, in the head replaceable cutting tool of the present invention, the cutting head and the holder are provided on a surface facing the central axis direction of the cutting head and a surface facing the central axis direction of the holder facing the surface. And a rotation restricting portion that restricts relative rotation around the central axis.

  In this case, since the rotation restricting portion for restricting the relative rotation of the cutting head and the holder around the central axis is formed on the surface of the cutting head and the surface of the holder facing the central axis direction, In the contact portion between the contact portion of the head and the cylindrical portion of the holder, the structure for restricting the relative rotation is not necessary. In other words, since the part that regulates the relative rotation and the part to be centered can be arranged at different places, each action at each part is stably and accurately performed.

  According to the head exchangeable cutting tool of the present invention, the cutting head and the holder can be easily and accurately aligned without complicating the manufacturing process.

It is a perspective view showing a head exchange type cutting tool concerning one embodiment of the present invention. It is a fragmentary sectional side view which shows the principal part of the head exchange type cutting tool of FIG. It is a perspective view which shows the front-end | tip shape of the holder of the head exchange type cutting tool of FIG. It is a side view which shows the front-end | tip shape of the holder of the head exchange type cutting tool of FIG. It is a front view which shows the front-end | tip shape of the holder of the head exchange type cutting tool of FIG. It is a perspective view which shows the cutting head of the head exchange type cutting tool of FIG. It is a side view which shows the cutting head of the head exchange type cutting tool of FIG. It is the front view which looked at the cutting head of the head exchange type cutting tool of FIG. 1 from the front end side. It is the rear view which looked at the cutting head of the head exchange type cutting tool of FIG. 1 from the holder side. It is a perspective view which shows the pin member of the head exchange type cutting tool of FIG. It is the front view which looked at the pin member of the head exchange type cutting tool of FIG. 1 from the front end side. It is a side view which shows the pin member of the head exchange type cutting tool of FIG. In the head exchange type cutting tool of FIG. 1, it is a figure explaining the centering of a pin member, a holder, and a cutting head performed when inserting a pin member in the cylinder part of a holder.

Hereinafter, a head replaceable cutting tool 1 according to an embodiment of the present invention will be described with reference to FIGS.
The head replaceable cutting tool 1 of the present embodiment is a head replaceable end mill.

1 and 2, the head exchangeable cutting tool 1 includes a cutting head 2 having a cutting edge, a holder 3 to which the cutting head 2 is detachably mounted, and a cutting head 2 that is screwed into the holder 3. And a pin member 4 to be fixed.
Here, the holder 3 has an axial shape, and the cutting head 2 has a cylindrical shape. The cutting head 2 is disposed coaxially with the holder 3 at one end along the direction of the central axis C1 of the holder 3. Yes. In the following description, the cutting head 2 side along the central axis C1 direction of the holder 3 is referred to as the distal end side, and the side opposite to the cutting head 2 is referred to as the proximal end side. Further, a direction perpendicular to the central axis C1 of the holder 3 is referred to as a radial direction, and a direction around the central axis C1 is referred to as a circumferential direction.

  The head-exchangeable cutting tool 1 is configured such that the end portion (base end portion) on the base end side of the holder 3 is detachably supported by the main shaft of the machine tool and is rotated about the central axis C1 to This is a head-exchangeable turning tool that cuts a workpiece with a cutting edge.

  The holder 3 is formed of a steel material, and a cross section perpendicular to the central axis C1 has a circular shape. The holder 3 is a cylindrical holder main body made of cemented carbide and a columnar cylindrical body on which the cutting head 2 is mounted by joining to an end portion (tip end portion) of the holder main body made of steel by brazing. A holder head portion.

  In FIG. 2, the tip 3A of the holder 3 is formed to have a smaller diameter than the other part (main body part) 3B. The distal end portion 3A of the holder 3 has a female screw hole 3D that opens in the radial center of the distal end surface 3C facing the distal end side and extends from the distal end surface 3C toward the proximal end side on the central axis C1. It has been drilled. The inner peripheral surface of the female screw hole 3D is subjected to female screw processing (not shown), and the female screw hole 3D is formed so as to be able to be screwed into a male screw portion 4A of the pin member 4 described later. .

  Further, the tip surface 3C of the holder 3 has a cylindrical shape that is smaller in diameter than the tip portion 3A and protrudes from the tip surface 3C toward the tip side, and is coaxial with the center axis C1 of the holder 3, A cylindrical portion 5 is formed which is elastically deformable outward in the radial direction perpendicular to the axis C1. An inner diameter of the cylindrical portion 5 is formed slightly larger than a male screw portion 4A of the pin member 4 described later. The base end portion (the portion corresponding to the tip surface 3C portion along the direction of the central axis C1) on the inner peripheral surface of the cylindrical portion 5 is the tip portion (the opening corresponding to the tip surface 3C portion) on the inner peripheral surface of the female screw hole 3D. Edge).

  As shown in FIGS. 3 to 5, the cylindrical portion 5 has a plurality of wall portions 5 </ b> A formed so as to be divided along the circumferential direction around the central axis C <b> 1 of the holder 3. These wall portions 5A are arranged at intervals in the circumferential direction around the central axis C1, and each wall portion 5A has an arcuate cross section perpendicular to the central axis C1. As described above, the plurality of wall portions 5A are arranged in the circumferential direction around the central axis C1, so that the tubular portion 5 has a cylindrical shape as a whole.

  A concave groove 5B extending along the circumferential direction is formed at the base end portion of the outer peripheral surface of the wall portion 5A. By forming such a concave groove 5B, the base portion of the wall 5A is thin.

  Further, the surface of the cylindrical portion 5 facing inward in the radial direction, that is, the inner peripheral surface of the wall portion 5A is gradually inclined outward in the radial direction along the central axis C1 toward the tip side of the holder 3. An inclined surface 5C is formed. The inclined surface 5C is formed at the tip of the inner peripheral surface of the wall 5A (tubular portion 5).

  The front end surface 3C of the holder 3 is formed with a plurality of concave portions 6 that are recessed toward the proximal end side and convex portions 7 that protrude toward the distal end side, and these are centered on the central axis C1. Are alternately arranged in the circumferential direction.

As shown in FIGS. 3 and 5, the concave portion 6 is a fan-shaped hole, and the convex portion 7 is a fan-shaped projection. 3 C of front-end | tip surfaces are made into the uneven | corrugated shape by arranging these recessed part 6 and the convex part 7 adjacent to the circumferential direction continuously.
The radially inner end of the recess 6 is continuous with the opening edge of the female screw hole 3D. A wall portion 5 </ b> A is erected at the radially inner end of the convex portion 7.

2 and 6 to 9, the cutting head 2 is made of cemented carbide, and has a tip surface 2A facing the tip side in the direction of the center axis C2, and a center axis C2 adjacent to the tip surface 2A. A plurality of cutting edges (not shown) are provided on the outer peripheral surface 2B facing radially outward in the direction perpendicular to the radial direction. The outer diameter of the cutting head 2 is slightly larger than the outer diameter of the tip 3A of the holder 3 (see FIG. 2).
Here, since the central axis C2 of the cutting head 2 is coaxial with the central axis C1 in a state where the cutting head 2 is mounted on the holder 3, the central axes C1 and C2 in the head replaceable cutting tool 1 are They are common axes.

  The cutting head 2 is formed with multi-stage mounting holes 8 extending along the central axis C <b> 2 and penetrating the cutting head 2. In FIG. 7, the inner peripheral surface of the mounting hole 8 has a central portion 8A having the smallest diameter along the direction of the central axis C2, and a distal end portion 8B located on the distal end side (the upper side in FIG. 7) of the central portion 8A. And the inner diameter of the base end portion (contact portion) 8C located on the base end side (lower side in FIG. 7) of the central portion 8A are substantially the same as each other, and from the inner diameter of the central portion 8A Large diameter.

  As shown in FIG. 2, the base end portion 8 </ b> C of the inner peripheral surface of the mounting hole 8 is disposed outward in the radial direction of the cylindrical portion 5 in a state where the cutting head 2 is attached to the tip of the holder 3. . The base end portion 8 </ b> C has a cylindrical hole shape corresponding to the cylindrical portion 5. Further, the inner diameter of the base end portion 8 </ b> C is slightly larger than the outer diameter of the cylindrical portion 5. And when the pin member 4 mentioned later is inserted in the cylindrical part 5 at the base end part 8C of the cutting head 2, this cylindrical part 5 is elastically deformed outward in the radial direction. 5 can be contacted. That is, the base end portion 8 </ b> C on the inner peripheral surface of the mounting hole 8 is an abutting portion on which the outer peripheral surface of the cylindrical portion 5 can abut.

  In addition, a portion of the central portion 8A on the inner peripheral surface of the mounting hole 8 that is located on the distal end side is an inclined surface 8D that gradually inclines outward in the radial direction along the central axis C2 direction toward the distal end side. It has become. Further, the mounting hole 8 has a ring shape so as to face the base end side in the direction of the central axis C2 and to connect the peripheral end edge on the base end side of the central portion 8A and the peripheral end edge on the front end side of the base end portion 8C. A surface 8E is formed. As shown in FIG. 2, a slight gap is formed between the annular surface 8 </ b> E and the surface facing the distal end side of the cylindrical portion 5 in a state where the cutting head 2 is attached to the distal end of the holder 3.

  The surface 2C facing the base end side of the cutting head 2 is formed with a plurality of concave portions 9 that are recessed toward the distal end side and convex portions 10 that protrude toward the base end side. They are alternately arranged in the circumferential direction around the central axis C2.

  As shown in FIGS. 6 and 9, the concave portion 9 is a fan-shaped hole, and the convex portion 10 is a fan-shaped projection. The concave portion 9 and the convex portion 10 are continuously arranged adjacent to each other in the circumferential direction, so that the surface 2C has an uneven shape.

  In FIG. 1 and FIG. 2, the concave portion 9 formed on the surface 2 </ b> C facing the proximal end side of the cutting head 2 and the distal end surface 3 </ b> C of the holder 3 with the cutting head 2 attached to the distal end of the holder 3. The convex portions 7 are in contact with each other. Further, the convex portion 10 formed on the surface 2 </ b> C facing the base end side of the cutting head 2 and the concave portion 6 formed on the distal end surface 3 </ b> C of the holder 3 are in contact with each other. Thereby, the recessed part 9 and the convex part 7 engage, and the convex part 10 and the recessed part 6 engage.

  In the head exchange type cutting tool 1, the relative rotation around the central axes C <b> 1 and C <b> 2 between the cutting head 2 and the holder 3 is restricted by engaging the concave portions 6 and 9 and the convex portions 7 and 10 as described above. ing. In this way, the surface 2C facing the central axis C2 direction of the cutting head 2 and the surface (front end surface) 3C facing the central axis C1 direction of the holder 3 facing the surface 2C are recessed portions 6 that engage with each other, 9 and a rotation restricting portion 11 having convex portions 7 and 10 are formed.

The pin member 4 is formed of a steel material. As shown in FIGS. 2 and 10 to 12, the pin member 4 has a base end portion along the direction of the central axis C <b> 3 (the base end portion here is the pin member 4 attached to the holder 3. The end of the holder 3 on the base end side is inserted and is located at one end of the pin member 4) and is subjected to male screw processing (not shown) and is formed to be screwed into the female screw hole 3D. A small-diameter male screw portion (screw portion) 4A and a tip portion along the direction of the central axis C3 (here, the tip portion refers to the end portion on the tip side of the holder 3 of the pin member 4 attached to the holder 3). And the other end of the pin member 4), the head 4B having the largest diameter, and a cylindrical shape located between the male screw 4A and the head 4B. The cutting head 2 is a holder. 3, the cylindrical portion 5 is brought into contact with the cylindrical portion 5 from the inside in the radial direction so that the cylindrical portion 5 Toward the outside of direction includes a the spreading portion 4C to elastically deform, the.
Here, the central axis C3 of the pin member 4 is coaxial with the central axis C1 in a state where the pin member 4 is inserted into the cylindrical portion 5 of the holder 3 and the male screw portion 4A is screwed into the female screw hole 3D. Therefore, the central axes C1 and C3 in the head exchangeable cutting tool 1 are common axes. Since the central axes C1 and C2 are common axes as described above, the central axes C1, C2 and C3 are common axes (coaxial).

  Of the head portion 4B of the pin member 4, the portion located on the base end side (the lower side in FIG. 12, the male screw portion 4A side positioned at one end of the pin member 4) is the base end side along the direction of the central axis C3. It becomes the inclined surface 4D which inclines toward the inner side of radial direction gradually as it goes to. The amount of displacement (that is, the inclination) in the radial direction per unit length along the central axis C3 direction on the inclined surface 4D is the radial displacement per unit length along the central axis C2 direction on the inclined surface 8D of the cutting head 2. The amount of displacement is substantially the same, so that the inclined surface 4D and the inclined surface 8D are easily in surface contact with each other over a wide range.

  Further, the portion located on the base end side of the expanded portion 4C of the pin member 4 has a tapered surface 4E that gradually inclines inward in the radial direction along the direction of the central axis C3 toward the base end side. It has become. That is, the taper surface 4E is formed so as to be gradually inclined outward in the radial direction as it is separated from the male screw portion 4A located at one end of the pin member 4 toward the head portion 4B located at the other end. Yes.

Next, the operation (centering) of the head exchangeable cutting tool 1 of the present embodiment configured as described above will be described with reference to FIG.
In FIG. 13A, when the cutting head 2 is placed on the distal end portion of the holder 3, the cylindrical portion 5 of the holder 3 is inserted into the proximal end portion 8 </ b> C of the mounting hole 8 of the cutting head 2. Further, the surface 2C facing the base end side of the cutting head 2 and the distal end surface 3C of the holder 3 are in contact with each other, and the corresponding concave portions 6 and 9 and the convex portions 7 and 10 are engaged with each other.
From this state, the pin member 4 is inserted into the cylindrical portion 5 of the holder 3 through the mounting hole 8 of the cutting head 2. Here, the arrow in the figure indicates the direction in which the pin member 4 is pushed (screwed) into the holder 3. In the state shown in FIG. 13A, the central axis C1 of the holder 3, the central axis C2 of the cutting head 2, and the central axis C3 of the pin member 4 are at different positions.

  Next, in FIG. 13B, the male screw portion 4A of the pin member 4 is screwed into and screwed into the female screw hole 3D (not shown in FIG. 13) of the holder 3. As a result, the pin member 4 enters the base 3 toward the proximal end side with respect to the holder 3 and is inserted into the cylindrical portion 5. At this time, the expanded portion 4C of the pin member 4 abuts on the cylindrical portion 5 from the inside in the radial direction, and elastically deforms the cylindrical portion 5 toward the outside in the radial direction to expand the cylindrical portion 5. The pin member 4 moves in the radial direction so that its central axis C3 coincides with the central axis C1 of the holder 3, so that the central axis C3 of the pin member 4 and the central axis C1 of the holder 3 are positioned coaxially.

  Specifically, the area where the outer peripheral surface of the expanded portion 4 </ b> C contacts the inner peripheral surface of each wall portion 5 </ b> A of the cylindrical portion 5 is distributed so as to be even in the circumferential direction, and the base of the pin member 4. The pin member 4 is arranged so that the amount of displacement of each wall portion 5A toward the outer side in the radial direction with respect to the amount of movement per unit length toward the end side (the amount of diameter expansion of the cylindrical portion 5) is uniform in the circumferential direction. The central axes C1 and C3 are made to coincide with each other by being moved in the radial direction. In the state shown in FIG. 13B, the central axis C1 of the holder 3 and the central axis C3 of the pin member 4 are thus coaxial, whereas the central axis C2 of the cutting head 2 is the central axis C1. , C3 is in a different position.

  Next, in FIG. 13C, when the pin member 4 is further screwed into the holder 3, the cylindrical portion 5 is further elastically deformed and is expanded outward in the radial direction. And the cylinder part 5 contact | abuts to the contact part (base-end part 8C of the attachment hole 8) of the cutting head 2 located in the radial direction outer side. By this contact, the cutting head 2 moves in the radial direction so that the central axis C2 thereof coincides with the central axis C1 of the holder 3, and the central axis C2 of the cutting head 2 and the central axis C1 of the holder 3 are coaxial. Is positioned.

  Specifically, of the outer peripheral surface of the cylindrical portion 5, the cutting head 2 is brought into contact with the proximal end portion 8 </ b> C from a portion relatively close to the proximal end portion 8 </ b> C, and further the diameter of the cylindrical portion 5 is increased so that the cutting head 2 Moved in the direction. Accordingly, the base end portion 8C is brought close to and comes into contact with a portion located on the outer circumferential surface of the cylindrical portion 5 on the opposite side of the circumferential direction from the portion. Such an action is performed at each part in the circumferential direction of the outer peripheral surface of the cylindrical part 5, so that the outer peripheral surface of the cylindrical part 5 uniformly contacts the inner peripheral surface of the base end part 8 </ b> C in the circumferential direction and the cutting head 2. The central axis C2 is made to coincide with the central axis C1 of the holder 3. In the state shown in FIG. 13C, the central axis C1 of the holder 3, the central axis C2 of the cutting head 2, and the central axis C3 of the pin member 4 are coincident with each other and are coaxial.

As shown in FIG. 2, when the pin member 4 is screwed into the holder 3 by a predetermined amount, the inclined surface 4D of the pin member 4 and the inclined surface 8D of the cutting head 2 come into contact with each other. Thereby, the cutting head 2 is clamped to the holder 3.
On the other hand, when the cutting head 2 subjected to the cutting process is replaced with another new cutting head 2, the pin member 4 is removed from the holder 3 by a procedure reverse to the above-described procedure. Thereby, the cylindrical portion 5 is restored and deformed, and is separated from the base end portion 8 </ b> C of the mounting hole 8 of the cutting head 2.

  As described above, according to the head-exchangeable cutting tool 1 of the present embodiment, the cylindrical portion 5 of the holder 3 is elastically deformed and brought into contact with the contact portion (base end portion 8C) of the cutting head 2. Since the centering (centering) of the holder 3 and the cutting head 2 is performed, the head-exchangeable cutting tool 1 is different from the centering by the conventional fitting in the cylinder part 5, the abutting part and the pushing part. High-precision polishing is not required for the expanded portion 4C. Specifically, according to the head-exchangeable cutting tool 1, only rough polishing or no polishing can be performed with respect to the cylindrical portion 5, the contact portion, and the expanded portion 4C. In particular, the cutting head 2 made of a hard cemented carbide is excellent in that polishing is unnecessary and the state after sintering can be used as it is for cutting.

  Thus, according to the present embodiment, the cutting head 2 and the holder 3 can be accurately and easily aligned without complicating the manufacturing process.

  Moreover, since it has the some wall part 5A formed so that the cylinder part 5 might be divided | segmented into the circumferential direction, when the pin member 4 pushes this cylinder part 5 outward toward a radial direction, it expands. The cylindrical portion 5 is more easily elastically deformed, and is more likely to come into contact with the contact portion. Therefore, the above-described operational effects can be obtained stably.

  Further, since the taper surface 4E is formed on the expanded portion 4C, the pin member 4 can be easily inserted into the cylindrical portion 5 and the wall portion 5A of the cylindrical portion 5 is located with respect to the central axis C1 of the holder 3. Since it is elastically deformed so as to be inclined, the tip of the wall portion 5A can easily come into contact with the contact portion. Therefore, the contact between the cylindrical portion 5 and the contact portion is reliably performed.

  In addition, since the inclined surface 5C is formed on the inner peripheral surface of the cylindrical portion 5, the pin member 4 is reliably guided into the cylindrical portion 5, and the pin member 4 is easily screwed into the holder 3.

  Further, on the surface 2C of the cutting head 2 and the front end surface 3C of the holder 3 facing in the direction of the central axis C1, a rotation restricting portion 11 that restricts the relative rotation of the cutting head 2 and the holder 3 around the central axis C1 is formed. Therefore, in the contact portion between the contact portion (base end portion 8C) of the cutting head 2 and the cylindrical portion 5 of the holder 3, the structure for restricting the relative rotation is not necessary. In other words, since the part that regulates the relative rotation and the part to be centered can be arranged at different places, each action at each part is stably and accurately performed.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

For example, in the above-described embodiment, the cylindrical portion 5 has a cylindrical shape as a whole, and the contact portion (base end portion 8C) of the cutting head 2 has a corresponding cylindrical hole shape. It is not limited. That is, the cylindrical part 5 has, for example, a polygonal cylindrical shape or an elliptical cylindrical shape having a non-circular cross section, and the abutting part of the cutting head 2 has a non-circular cross section corresponding to the shape of the cylindrical part 5, for example, Alternatively, it may have an elliptical column shape.
In this case, the cylindrical part 5 and the contact part have the effect of regulating the relative rotation between the cutting head 2 and the holder 3 in addition to the above-described centering effect.

In the above-described embodiment, the head replaceable cutting tool 1 is a head replaceable end mill. However, the present invention is not limited to this. For example, other head replaceable thread cutting tools (tap) are used. And so on.
In addition, although the cutting edge of the cutting head 2 is formed on the front end surface 2A and the outer peripheral surface 2B, the cutting edge may be formed on the front end surface 2A or the outer peripheral surface 2B.

DESCRIPTION OF SYMBOLS 1 Head exchange type cutting tool 2 Cutting head 2C The surface which faces the base end side of a cutting head (surface which faces the center axis direction of a cutting head)
3 Holder 3C Holder end surface (surface facing the center axis direction of the holder)
4 Pin member 4A Male screw part (screw part)
4C Expanding part 4E Tapered surface 5 Tube part 5A Wall part 8C Base end part (contact part) of mounting hole
11 Rotation restriction part C1 Center axis of holder

Claims (4)

A cutting head having a cutting edge;
A holder to which the cutting head is detachably mounted;
A pin member for fixing the cutting head by screwing to the holder, and a head replaceable cutting tool comprising:
The holder has a cylindrical portion that is coaxial with the central axis of the holder and is elastically deformable outward in the radial direction perpendicular to the central axis.
The cutting head has an abutting portion that is disposed on the outer side of the cylindrical portion in the radial direction and on which the cylindrical portion can abut,
The head-replaceable cutting tool, wherein the pin member has a push-out portion that abuts the cylindrical portion from the inside in the radial direction and elastically deforms the cylindrical portion toward the outside in the radial direction. . The head replaceable cutting tool according to claim 1,
The cylinder part has a plurality of wall parts formed so that it may be divided along the peripheral direction around the central axis of the holder, The head exchange type cutting tool characterized by things. The head replaceable cutting tool according to claim 1 or 2,
The said expansion part has a taper surface which inclines toward the outward of the said radial direction gradually as it separates toward the other end from the thread part which is formed in the end of the said pin member, and is screwed together in the said holder. Features a head-changing cutting tool. It is a head exchange type cutting tool as described in any one of Claims 1-3,
Relative rotation of the cutting head and the holder around the central axis is restricted on a surface facing the central axis direction of the cutting head and a surface facing the central axis direction of the holder facing the surface. A head exchangeable cutting tool, wherein a rotation restricting portion is formed.

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