JP2003275916A - Edge exchangeable cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an edge exchangeable cutting tool with an edge smoothly removable from a tool body, achieving easy miniaturization with a less number of parts and lower cost. <P>SOLUTION: A through-hole 117 ranging from the outer periphery face of the tool body 110 to a mounting hole 112 is formed obliquely to the direction of an axial line O which tends to the rear end in the direction of the axial line O as tending to the radially inward direction. A pull-in bolt 120 having a recessed portion 125 with a further smaller outer diameter at a front end portion 122 is screwed into the through-hole 117. A pull-in member 150 is provided with a fitting portion 160 having a protruded portion 163 corresponding to the recessed portion 125. The front end portion 122 of the pull-in bolt 120 and the fitting portion 160 of the pull-in member 150 are fitted to each other in such a manner that the recessed portion 125 and the protruded portion 163 thereof are fitted to each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade-interchangeable cutting tool in which a blade is detachably attached to a tool body.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of blade-interchangeable cutting tool, a rear end side portion of a blade portion having a cutting portion having at least one cutting blade and a retracting member (retracting portion) are detachable. By connecting the blade portion and the retractable member which are coupled to each other so as to be inserted into the mounting hole formed in the tool body, and the retractable member is retracted toward the rear end side in the axial direction of the tool body, In some of the blades, a blade portion connected to a retracting member is retracted to the rear end side in the axial direction of the tool body and is detachably mounted.

For example, Japanese Patent Publication No. 11-504269 and US
There is a blade-interchangeable cutting tool as disclosed in 2001 / 0009636A1, in which a retracting member connected to the blade is screwed into a tool body in a direction inclined with respect to an axial direction. The blade and the retracting member are retracted toward the rear end side in the axial direction by being pressed by the front end surface of the bolt, and the retracting member is disposed on the rear end side in the axial direction. A spring that presses toward is provided.

In such a cutting tool with exchangeable blade portion, when the pulling bolt is loosened to release the pressing force to the pulling member, the pulling member is returned to the axial line by the restoring force of the spring provided at the rear end side of the pulling member. The blade portion can be removed from the tool body by being pushed out toward the tip end in the direction and then releasing the connection between the blade portion and the retracting member. However, since the pushing force for pushing the retracting member toward the tip end side in the axial direction depends only on the restoring force of the spring, for example, a tapered portion is formed in the blade portion and a tapered hole is formed in the mounting hole, When the blade part is mounted on the tool body and the taper part of the blade part is tightly tightened by the taper hole of the mounting hole, the restoring force of this spring alone will not provide sufficient pushing force, resulting in a smooth operation. There is a possibility that the blade part cannot be removed.

Here, when removing the blade portion from the tool body, it is possible to solve the shortage of the pushing force applied to the retracting member toward the tip end in the axial direction, for example, as shown in FIG. 5, WO98 / 50187. There is a blade-interchangeable cutting tool 10 disclosed in US Pat. This is because the pulling member 30 is screwed into the tool body 11 so as to pass through the through hole 31 of the pulling member 30 housed in the mounting hole 12 of the tool body 11, and the pulling member 30 is moved toward the rear end side in the direction of the axis O. It is pulled in or pushed out to the tip side in the direction of the axis O.

The retracting bolt 20 is formed with two tapered surfaces 21 and 21 whose outer diameter is gradually reduced toward the central portion in the longitudinal direction, while the retracting member 30 has a through hole 31. Has an elliptical shape in which the positions of the axes are eccentric to each other in the vicinity of the two openings, and the taper holes 32 become larger toward the radially outer side.
32 is formed. Then, by screwing the pull-in bolt 20 into the tool body 11, one tapered surface 21 of the pull-in bolt 20 presses one tapered hole 32 in the through hole 31 of the pull-in member 30 to move the pull-in member 30 in the axis O direction. By pulling it toward the rear end side and loosening the pull-in bolt 20 from the tool body 11, another tapered surface 21 of the pull-in bolt 20 presses another tapered hole 32 in the through hole 31 of the pull-in member 30, The pull-in member 30 is pushed out toward the tip side in the direction of the axis O.

[0007]

However, in such a blade-interchangeable cutting tool 10 as shown in FIG. 5 (b), the retracting bolt 20 cannot be integrally formed, so that a plurality of parts are required. Since it is necessary to configure the retractable bolt 20 by combining them, the number of parts constituting the blade-interchangeable cutting tool is increased, which leads to an increase in cost, and the blade-interchangeable cutting tool itself can be miniaturized. It was difficult.

The present invention has been made in view of the above problems, and the blade portion can be smoothly removed from the tool body, the number of parts is small, the cost can be suppressed, and the blade can be easily miniaturized. An object is to provide a part exchange type cutting tool.

[0009]

[Means for Solving the Problems] By solving the above problems,
In order to achieve such an object, the blade-interchangeable cutting tool according to the present invention has a drawing-in portion of a blade portion having a cutting portion provided with at least one cutting blade in an attachment hole formed in a tool body. When being inserted, the retracted portion is retracted toward the rear end side in the axial direction of the tool body, so that the blade portion having this retracted portion is retracted toward the rear end side in the axial direction of the tool body and is removable. A blade-interchangeable cutting tool to be mounted on the tool body, wherein a through hole is formed in the tool body from the outer peripheral surface thereof to the mounting hole in a direction inclined with respect to the axial direction. A draw-in bolt having a concave portion with a smaller outer diameter or a convex portion with a larger outer diameter in the tip side portion is screwed into the hole, and the outer peripheral surface of the pull-in portion is cut out by the cut-in portion of the draw-in bolt. Portion having a convex portion corresponding to the portion or a concave portion corresponding to the convex portion of the pull-in bolt is formed, and the tip side portion of the pull-in bolt and the fitting portion of the pull-in portion are concave portions formed in them. And projections are fitted to each other so as to fit each other, and by screwing the pull-in bolt so as to move to one direction side in the longitudinal direction of the through hole, the concave portion or the convex portion of the pull-in bolt is The wall surface facing the rear end side in the axial direction abuts against and presses the wall surface facing the front end side in the axial direction in the convex portion or the concave portion of the retracting portion, and the retracting portion is retracted toward the rear end side in the axial direction. On the other hand, by screwing the pull-in bolt so as to move it to the other direction side in the longitudinal direction of the through-hole, the axial direction in the concave portion or the convex portion of the pull-in bolt is increased. The wall surface facing the front end side abuts against and presses the wall surface facing the rear end side in the axial direction of the convex portion or the concave portion of the retracting portion, and the retracting portion is pushed out to the front end side in the axial direction. It is what In the blade portion exchangeable cutting tool of the present invention having such a configuration, when the blade portion is removed from the tool body, the pull-in bolt is screwed (loosened) toward the other direction side in the longitudinal direction of the through hole. , The wall surface of the recessed portion or the protruding portion of the leading end portion of the draw-in bolt that faces the tip end side in the axial direction contacts the wall surface of the protruding portion or the recessed portion of the fitting portion that faces the rear end side in the axial direction and presses. By doing so, this retracted portion can be pushed out toward the distal end side in the axial direction with a sufficient pushing force, and the step of removing the blade portion can be smoothly performed. Moreover, when the leading end side portion of the retractable bolt and the fitting portion of the retracted portion are fitted to each other, the retractable bolt is screwed into the through hole and the retracted portion is inserted into the mounting hole at the same time. The front end side portion and the fitting portion of the retracting portion can be fitted to each other by fitting the concave portion and the convex portion formed therein, and as in the conventional case, the retracting bolt can be attached to a plurality of members. It is not necessary to combine them, the number of parts does not increase, the cost is suppressed, and the size can be easily reduced.

The retracting portion of the blade portion is a retracting member that is detachably connected to the rear end side portion of the blade portion, and the blade portion and the retracting member thus connected are inserted into the mounting hole. In addition, by pulling the retracting member toward the rear end side in the axial direction of the tool body, the blade portion connected to this retracting member is retracted toward the rear end side in the axial direction of the tool body and is removable. It is preferable to be attached to.
With such a configuration, since the fitting portion into which the tip end side portion of the pull-in bolt is fitted is formed in the pull-in member that is separate from the blade portion, the blade portion is unnecessarily enlarged to form this fitting portion. Since the pressing force of the pull-in bolt does not directly act on the blade portion, eccentricity of the blade portion does not occur.

Further, the blade portion has a taper portion having a substantially truncated cone shape whose outer diameter gradually decreases toward the rear end side.
The mounting hole has a tapered hole of a substantially truncated cone shape whose inner diameter gradually decreases toward the rear end side, and the outer peripheral surface of the tapered portion of the blade portion is the inside of the tapered hole of the mounting hole. It is preferable that the blade portion is detachably mounted by pressing the peripheral surface. With such a configuration, as the retracted portion is retracted toward the rear end side in the axial direction, when the blade portion is retracted toward the rear end side in the axial direction of the tool body, the outer periphery of the tapered portion of the blade portion The surface can uniformly press the inner peripheral surface of the tapered hole of the mounting hole without deviation, and it becomes possible to align the axis of the blade part with the axis of the tool body to perform centering, The tapered hole of the mounting hole allows the tapered portion of the blade portion to be firmly tightened, so that the mounting rigidity of the blade portion can be kept high. And, even though the blade portion is firmly tightened in this way, when it is removed from the tool body, the pull-in portion can be surely pushed out by a sufficient pushing force given from the pull-in bolt,
The blade can be removed smoothly.

Further, the fitting portion of the pull-in portion has a wall surface facing the circumferential direction of the tool body, and the tip side portion of the pull-in bolt and the fitting portion of the pull-in portion are fitted to each other. At this time, the outer peripheral surface of the leading end portion of the retracting bolt and the wall surface of the fitting portion of the retracting portion facing in the circumferential direction are arranged to face each other, and the retracting portion relative to the tool body in the circumferential direction. Rotation is preferably prevented. With such a configuration, when the blade is attached to the tool body, the retracted portion is not rotated relative to the tool body in the circumferential direction, and the blade is stably attached. can do.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the blade-interchangeable cutting tool 100 according to the present embodiment includes a tool body 110 that is rotated around an axis O and a tool body 1 that is rotated.
A blade portion 130 that is detachably attached to and fixed to
The drawing member 150 is used to mount the blade portion 130 on the tool body 110 and forms a drawing portion of the blade portion 130.

As shown in FIGS. 1 and 2, the tool main body 110 is made of, for example, steel and has a front end portion with a small outer diameter and a rear end portion with a large outer diameter directed toward the rear end side in the axis O direction. The tapered surface 110 whose outer diameter gradually increases in accordance with
It is formed in a substantially multi-stage cylindrical shape centered on the axis O connected by A, and a mounting hole 112 centered on the axis O is bored from the front end surface 111 toward the rear end side.

The mounting hole 112 has a taper hole 113 having a substantially truncated cone shape in which the inner diameter gradually decreases from the front end surface 111 of the tool body 110 toward the rear end with a constant gradient, and the taper hole 113. A substantially cylindrical hole-shaped first storage hole 11 which is continuous with the rear end side and extends toward the rear end side with a constant inner diameter.
4 and a substantially cylindrical column which is continuous to the rear end side of the first storage hole 114 and which extends toward the rear end side with a constant inner diameter smaller than the inner diameter of the first storage hole 114 and opens to the rear end surface 116 of the tool body 110. It is composed of a hole-shaped second storage hole 115.

The tool body 110 includes the tool body 1
10 from the tapered surface 110A on the outer peripheral surface to the mounting hole 11
A through hole 117 that penetrates to the second storage hole 115 in No. 2 is formed with an internal thread portion 118 on its inner peripheral surface. The direction of the axis P of the through hole 117 (longitudinal direction)
Is inclined with respect to the axis O direction so as to be directed toward the rear end side in the axis O direction according to the radially inward direction,
When the axis P extends radially inward (toward the rear end in the axis O direction), the axis P intersects the axis O.

Into the through hole 117, a pull-in bolt 120 having a substantially multi-stage cylindrical shape centered on the axis P of the through hole 117.
And the female screw portion 118 of the through hole 117 is inserted.
On the other hand, the male screw portion 121 formed on the outer peripheral surface of the rear end side portion of the pull-in bolt 120 is screwed in, and the front end side portion 122 of the pull-in bolt 120 is projected into the second storage hole 115 in the mounting hole 112. Has been.

Further, the tip side portion 12 of the pull-in bolt 120
2 is formed in a substantially cylindrical shape having an outer diameter slightly smaller than the outer diameter of the rear end side portion where the male screw portion 121 is formed. Further, a small-diameter portion 124 having an outer diameter smaller than the outer diameter of the tip side portion 122 is formed on the tip side portion 122 at a position spaced apart from the tip surface 123 of the retractable bolt 120 by a predetermined distance. This allows
The recess 12 that is recessed one step from the outer peripheral surface of the tip side portion 122
5 will be formed.

The recess 125 stands upright on the curved surface 126 forming the outer peripheral surface of the small-diameter portion 124, and in a direction orthogonal to the axis P direction from the curved surface 126, and the tip side portion 122.
And a pair of wall surfaces 127, 128 which intersect the outer peripheral surface of the shaft P and face one direction side (the lower right direction in FIG. 1) and the other direction side (the upper left direction in FIG. 1) of the axis P and which face each other. There is.

Here, the axis P is inclined with respect to the direction of the axis O toward the rear end side in the direction of the axis O toward the inner side in the radial direction. The wall surface 127 that faces the one side in the direction becomes the wall surface 127 that faces the rear end side in the axis O direction in general, and the wall surface 128 that faces the other side in the direction of the axis P in the recess 125 generally extends in the direction of the axis O. Wall 12 facing the tip side
It becomes 8.

Further, as shown in FIG. 2, on the tip surface 111 of the tool main body 110 having a substantially ring shape due to the mounting hole 112 being provided, the positions are opposite to each other with respect to the axis O. Then, a pair of keys 119A and 119B protruding toward the tip side in the direction of the axis O is formed. One of the pair of keys 119A and 119B (key 119A) is different from the other (key 119B).
The width in the circumferential direction is long, and the pair of keys 119A,
The sizes 119B are different from each other.

As shown in FIG. 3, the blade portion 130 is made of, for example, cemented carbide, and has a cutting portion 131 in which at least one cutting edge is formed at the tip, and a step portion on the rear end side of the cutting portion 131. And a taper portion 132 having a substantially circular truncated cone shape whose outer diameter gradually decreases with a constant gradient as it goes toward the rear end side, and a rear end side portion connected to the rear end side of the taper portion 132. 133, and is formed around the axis O. It should be noted that the taper portion 132 has a one-sided taper angle θ set in a range of 2 to 25 °.

Since the cutting portion 131 of the blade portion 130 is connected to the taper portion 132 connected to the rear end side through a step, the cutting portion 131 stands upright from the outer peripheral surface of the taper portion 132. A wall surface 131A that intersects with the outer peripheral surface of the cutting portion 131 and faces the rear end side in the axis O direction is formed.

On the wall surface 131A of the cutting portion 131 facing the rear end side in the direction of the axis O, the pair of keys 119A and 119B formed on the tip surface 111 of the tool body 110 are aligned with each other with respect to the axis O. A pair of key grooves 141A and 141B that are located on the opposite side and are recessed toward the tip side in the direction of the axis O and open to the outer peripheral surface of the cutting portion 131 are formed. These pair of keyways 141A, 141B
Also, as for (1) (the key groove 141A), the width in the circumferential direction is longer than that of the other (the key groove 141B),
The pair of key grooves 141A and 141B have different sizes.

The rear end portion 133 of the blade portion 130
Is a substantially cylindrical shaft portion 135 connected to the rear end side of the tapered portion 132 via a step portion, and an end portion 136 connected to the rear end side of the shaft portion 135 and forming the rear end portion of the blade portion 130. That is, the hook portion 134.

The end portion 136 of the hook portion 134, when viewed toward the tip side in the direction of the axis O so as to face the flat end surface 137 (the rear end surface of the blade portion 130) of FIG. As shown in FIG. 3, each of the three corner portions 138 of the end portion 136 having a substantially triangular shape has a step toward the radially outer side with respect to the outer peripheral surface of the shaft portion 135. It is projected. The three side surfaces 139 of the end 136 are flat surfaces, and the three corner portions 1 where the three side surfaces 139 intersect with each other.
38 ... Three notch surfaces 139A ... Are formed by notching a portion near the flat surface.

Here, the three corners 138 ... At the end 136 of the hook portion 135 project one step radially outward from the outer peripheral surface of the shaft 135, so that these corners 138 ... Stands upright from the outer peripheral surface of the shaft portion 135, and the side surface 139 of the end portion 136 and the cutout surface 139A.
Wall 1 that intersects with and faces the tip side in the direction of the axis O
40 ... are formed.

The axis O at these corners 138 ...
The wall surfaces 140, which face the front end side in the direction, are formed as curved surfaces with the axis O as the center and the apexes of which form part of the peripheral surface of a virtual substantially conical body that faces the front end side in the direction of the axis O. It is inclined toward the rear end side in the direction of the axis O according to the outward direction.

In addition, the wall surfaces 140 of the corner portions 138 facing the tip side in the direction of the axis O are hook portions 134.
The radius of curvature is set to 0.02 to 0.2 mm when viewed in a cross section (a cross section orthogonal to the outer peripheral surface of the shaft portion 135 and parallel to the axis O) with respect to the outer peripheral surface of the shaft portion 135. Are smoothly connected via curved surfaces 140A ... Which have a substantially arc shape (or a substantially elliptical arc shape). In addition, this hook portion 13
The entire hook portion 134 including the end portion 136 of No. 4 has an axis O
Is rotationally symmetric with respect to the three-fold axis. (Here, rotational symmetry refers to the property that the same figure is repeated by rotation of 2π / n radian (n is a positive integer) when a symmetry operation of rotating a figure around one axis is performed, The rotation axis is called n-axis.)

As shown in FIG. 4, the pull-in member 150 is made of, for example, steel and has a substantially columnar front end portion 151 and a front end portion 151 which is connected to the rear end side of the front end portion 151. The rear end portion 152 has a substantially columnar shape and has an outer diameter one step smaller than the outer diameter, and is formed around the axis O. Retracting member 15
A hook hole 154 that opens to the end surface 153 (the front end surface of the retracting member 150) is formed in the front end side portion 151 of 0, and the axis O is connected so as to communicate with the rear end side of the hook hole 154. A hook accommodating hole 155 having a substantially cylindrical hole shape with a constant inner diameter at the center is formed.

The hook hole 154 is formed in the tip side portion 1
When viewed toward the rear end side in the direction of the axis O so as to face the end surface 153 of 51, as shown in FIG.
It has a substantially equilateral triangle shape. Three inner wall surfaces 1 forming the inner peripheral surface 156 of the hook hole 154 having the substantially equilateral triangle shape.
57 ... Have flat surfaces respectively, and three corner portions 158 where these three inner wall surfaces 157 ... Cross each other.
The vicinity is constituted by an arcuate inner wall surface 157A having an arcuate cross section, and the intersecting portions of the inner wall surfaces 157 ... Are smoothly connected.

Here, since the hook hole 154 has a substantially equilateral triangle shape as described above, the blade portion 13 is formed.
0 has a shape corresponding to the end portion 136 of the hook portion 134, and the end portion 136 of the hook portion 134 and the shaft portion 1
35 is set to have a size that allows passage, and opens on the end surface 153 of the front end portion 151 of the retracting member 150.

Further, the hook hole 154 having a substantially equilateral triangle shape is formed.
Since the hook portion storage hole 155 having a substantially cylindrical hole shape is formed so as to be continuous with the rear end side, the hook portion storage hole 1
55 from the inner peripheral surface of the hook hole 154.
Six wall surfaces 159, which intersect the three inner wall surfaces 157 of 6 and face the rear end side in the axis O direction, are formed so as to be located around the hook hole 154.

The wall surfaces 159 located around the hook hole 154 and facing the rear end side in the direction of the axis O are shown in FIG.
As shown in (c), the end portion 1 of the hook portion 134 described above.
The peripheral surface of an imaginary substantially conical body with the apex facing the front end side in the axis O direction so as to correspond to the shape of the wall surface 140 ... Is formed as a curved surface forming a part of the above, and is inclined toward the rear end side in the direction of the axis O along the radially outward direction. In addition, this hook hole 154
Further, the entire tip end side portion 151 of the retracting member 150 including the hook storing hole 155 is rotationally symmetric with the axis O as the axis of three times.

At the rear end side portion 152 of the retracting member 150,
By cutting out the outer peripheral surface, the tip side portion 122 of the pull-in bolt 120 can be fitted, and the convex portion having a shape corresponding to the concave portion 125 formed in the tip side portion 122 of the pull-in bolt 120. Fitting part 1 having 163
60 is formed.

As shown in FIG. 4C, the fitting portion 160 is centered on an axis P1 which is parallel to the axis P of the through hole 117 and intersects with the axis O in the same manner as the axis P. It has a shape that is cut out obliquely by a virtual multi-stage cylindrical body that has substantially the same shape.

More specifically, the fitting portion 160 has a first concave curved surface 161 curved around the axis P1 with a size corresponding to the outer peripheral surface of the male screw portion 121 located at the rear end side portion of the pull-in bolt 120. The first concave curved surface 161 is connected to the rear end side and is curved about the axis P1 by a size corresponding to the outer peripheral surface of the front end side portion 122 of the retracting bolt 120, and
The second concave curved surface 16 slightly protruding from the concave curved surface 161
2 and a convex portion that is continuous with the rear end side of the second concave curved surface 162 and has a size corresponding to the small diameter portion 124 of the front end side portion 122 of the retracting bolt 120, and that further protrudes from the second concave curved surface 162. And 163.

The convex portion 163 of the fitting portion 160 is curved about the axis P1 with a size corresponding to the outer peripheral surface of the small diameter portion 124 of the tip side portion 122 of the retracting bolt 120, that is, the curved surface 126 of the concave portion 125. The curved surface 164 extends in a direction orthogonal to the direction of the axis P1 to form a rear end surface of the retracting member 150, intersects the curved surface 164, and intersects with the axis P.
A wall surface 165 that faces one direction in one direction (the lower right direction in FIG. 4C) and stands upright from the second concave curved surface 162 in a direction orthogonal to the direction of the axis P1 and intersects the curved surface 164 to intersect the axis P1. And a wall surface 166 facing the other direction (upper left direction in FIG. 4C).

Here, the direction of the axis P1 is parallel to the direction of the axis P and is inclined with respect to the direction of the axis O toward the rear end side of the direction of the axis O along the radially inward direction. Therefore, the wall surface 165 of the convex portion 163, which faces the one direction side of the axis P1 direction, generally becomes the wall surface 165 which faces the rear end side of the axis O direction, and also faces the other side of the convex portion 163 direction of the axis P1 direction. The wall surface 166 generally has an axis O.
The wall surface 166 faces the tip side in the direction.

Further, the fitting portion 160 is provided with the pull-in bolt 1
A first concave curved surface 16 that is curved about the axis P1 and has a shape that is cut out obliquely by an imaginary multi-stage cylindrical body having an axis P1 that is substantially the same shape as 20.
Since it has the curved surface 164 of the 1st, 2nd concave curved surface 162 and the convex part 163, it has a wall surface which faces the circumferential direction around the axis O.

In the state where the blade portion 130 having the above-mentioned structure is attached to the tool body 110, the blade portion 13
End portion 13 of the hook portion 134 forming the rear end side portion 133
6 is inserted into and passed through a hook hole 154 formed in the front end side portion 151 of the retracting member 150, and is housed in a hook portion housing hole 155 located on the rear end side of the hook hole 154.

At this time, the hook portion 1 having a substantially equilateral triangle shape.
From the axis O at the end 136 of 34, three corners 138
The direction going to one of the ... and the direction going from the axis O in the hook hole 154 having a substantially equilateral triangle shape to one of the three corners 158 ... intersect at an intersection angle of about 60 °. That is, the blade portion 130 and the retracting member 150 are out of phase with each other by about 60 °.

The wall surfaces 140 of the three corners 138 of the end 136 of the hook portion 134, which face the front end side in the direction of the axis O, face the rear end side of the hook hole 154 in the direction of the axis O. By being arranged so as to face the wall surfaces 159 ... And being in close contact with each other,
The relative movement of the blade portion 130 and the retracting member 150 in the direction away from each other in the axis O direction is prevented.

Here, the wall surface 14 facing the tip side in the direction of the axis O in the corners 138 of the end 136 of the hook portion 134.
0 and the wall surface 159 located around the hook hole 154 and facing the rear end side in the direction of the axis O are formed as a curved surface forming a part of the peripheral surface of the virtual substantially conical body as described above. Therefore, these contact surfaces also form a curved surface with the axis O as the center and the apexes thereof become a part of the peripheral surface of a virtual substantially conical body that faces the tip side in the direction of the axis O, and the outer surface in the radial direction. Inclining toward the rear end side in the direction of the axis O as it goes toward the side.

In this way, the blade portion 130 and the retracting member 150, which are in a connected state by being prevented from moving relative to each other in the direction of the axis O, are inserted into the mounting hole 112 formed in the tool body 110. The substantially frustoconical taper portion 132 of the blade portion 130 is housed in the substantially frustoconical taper hole 113 of the mounting hole 112, and the rear end side portion 133 (hook portion 134) of the blade portion 130 is formed. The leading end side portion 151 of the retracting member 150 and the mounting hole 112 have a substantially cylindrical hole shape.
It is accommodated in the accommodating hole 114, and the rear end side portion 152 of the retracting member 150 is inserted so as to be accommodated in the second accommodating hole 115 having a substantially cylindrical hole shape of the mounting hole 112.

Further, the tool main body 11 is fitted to the pair of key grooves 141A and 141B formed on the wall surface 131A of the cutting portion 131 of the blade portion 130 facing the rear end side in the direction of the axis O.
A pair of keys 119A, 1 formed on the front end surface 111
19B are fitted to each other to prevent relative rotation of the blade portion 130 in the circumferential direction around the axis O with respect to the tool body 110. The pair of keyways 141A, 141
The larger key groove 119A of the pair of key grooves 119A and 119B is fitted to the larger key groove 114 of B, and the smaller key 119B is fitted to the smaller key groove 141B. Has been made.

Then, the rear end portion 15 of the retracting member 150.
The fitting body 160 formed on the tool body 110
The front end side portion 122 of the pull-in bolt 120 screwed into the through hole 117 is fitted. At this time, the first concave curved surface 161 of the fitting portion 160 is not attached to the pull-in bolt 120.
Is arranged so as to face the outer peripheral surface of the male screw portion 121 of
The second concave curved surface 162 of the fitting portion 160 is arranged so as to face the outer peripheral surface of the tip end side portion 122 of the retracting bolt 120, and the convex portion 163 of the fitting portion 160 is a recessed portion of the tip end side portion 122 of the retracting bolt 120. It is in a state of being fitted in 125.

In a state where the tip end side portion 122 of the pull-in bolt 120 is fitted into the fitting portion 160 of the pull-in member 150 and the concave portion 125 and the convex portion 163 formed therein are fitted in each other, the convex portion 163 is formed. Is arranged so as to face the curved surface 126 of the concave portion 125, and the wall surface 165 of the convex portion 163 facing the rear end side in the axis O direction faces the wall surface 128 of the concave portion 125 facing the front end side in the axis O direction. And the wall surface 166 of the convex portion 163 facing the front end side in the direction of the axis O is the concave portion 125.
Is arranged so as to face the wall surface 127 facing the rear end side in the direction of the axis O in FIG.

Here, the curved surface 16 of the first concave curved surface 161, the second concave curved surface 162, and the convex portion 163 forming the fitting portion 160.
4 has a wall surface that is curved so as to follow the outer peripheral surface of the draw-in bolt 120 and faces the circumferential direction, and the outer peripheral surface of the male screw portion 121, the outer peripheral surface of the tip end side portion 122, and the convex portion 125 in the draw-in bolt 120. By being arranged so as to face the curved surface 126 of and contacting each other,
The front end side portion 122 of the retracting bolt 120 is the retracting member 150.
In the state of being fitted in the fitting portion 160 of the
The relative rotation of 50 in the circumferential direction about the axis O with respect to the tool body 110 is prevented.

Further, the retracting bolt 120 is the tool body 110.
The lead-in bolt 120 is screwed toward the one side of the axis P direction (lower right direction in FIG. 1), that is, the rear end side in the axis O direction with respect to the through hole 117 formed in. Are moved to one side of the through hole 117 in the axis P direction and to the rear end side in the axis O direction.

Then, the tip side portion 1 of the pull-in bolt 120
The wall surface 127 of the concave portion 125 formed in 22 facing the rear end side in the direction of the axis O is the fitting portion 160 of the retracting member 150.
The retracting member 150 is retracted toward the rear end side in the axis O direction by abutting against and pressing the wall surface 166 of the convex portion 163 formed in the direction facing the tip side in the axis O direction, and the retracting member 150 is retracted. The blade portion 140 having the rear end side portion 133 connected to the front end side portion 151 is also drawn into the mounting hole 112 toward the rear end side in the direction of the axis O.

As a result, the tapered portion 132 of the blade portion 130 is formed.
The substantially entire outer peripheral surface of the tool presses substantially the entire inner peripheral surface of the tapered hole 113 of the mounting hole 112, and the axis O of the blade portion 130 and the axis O of the tool body 110 are aligned with each other to perform centering. That is, the blade portion 130 is detachably attached and fixed to the tool body 110.

Next, the process of mounting the blade portion 130 on the tool body 110 will be described. First, the mounting hole 1 of the tool body 110
12, the retracting member 150 is inserted toward the rear end side in the direction of the axis O, and the through hole 1 of the tool body 110 is inserted.
The pull-in bolt 120 is screwed into 17 so as to be inserted toward one side in the axis P direction, that is, toward the rear end side in the axis O direction.

Then, the fitting portion 160 of the retracting member 150 and the tip side portion 122 of the retracting bolt 120 inserted into the mounting hole 112 and the through hole 117 having the axes O and P inclined to each other are formed therein. Concave portion 125 and convex portion 16
3 and 3 are fitted to each other so as to fit each other, and the relative rotation of the retracting member 150 with respect to the tool body 110 in the circumferential direction is blocked.

After that, a hook hole 154 having a substantially equilateral triangle shape that opens into the end surface 153 of the retracting member 150 inserted into the mounting hole 112 and an end portion 136 having a substantially equilateral triangle shape of the hook portion 134 of the blade portion 130. The blade portion 130 is inserted toward the rear end side of the attachment hole 112 in the direction of the axis O while the blade portion 130 and the retracting member 150 are in phase.

As a result, the end portion 136 of the hook portion 134 is
An end 136 of the hook portion 134 is inserted into and passed through a hook hole 154 that is formed to have a size that allows the end portion 136 of the hook portion 134 to be located in the hook portion storage hole 155, and , The shaft portion 1 of the hook portion 134
35 is located in the hook hole 154.

Then, the blade portion 130 is rotated relative to the retracting member 150 in the circumferential direction about the axis O by a predetermined angle (about 60 ° in this embodiment), whereby the blade portion 130 is rotated.
And the phase difference between the retracting member 150 and the retracting member 150 is about 60 °. At this time, the tip surface 11 of the tool body 110
Keys 119A and 119B formed on the blade 1 and the blade portion 130
The keyways 141A and 141B formed in the wall surface 131A of the cutting portion 131 facing the rear end side in the direction of the axis O,
The corresponding sizes are arranged so as to face each other.

Next, by further inserting the blade portion 130 into the tool body 110 toward the rear end side in the axis O direction, the cutting portion 131 of the blade portion 130 faces the rear end side in the axis O direction. Key groove 141 formed on the wall surface 131A
A and 141B and keys 119A and 119B formed on the tip surface 111 of the tool body 110 are fitted to each other with corresponding sizes, and the circumference of the blade portion 130 around the axis O with respect to the tool body 110 is fitted. Relative rotation in the direction is prevented.

After that, while maintaining the state that the phase difference between the blade portion 130 and the retracting member 150 is about 60 °, the retracting bolt 120 screwed into the through hole 117 of the tool body 110 is inserted into the retracting bolt 120. 120 so that it moves to one direction side of the axis P (lower right direction in FIG. 1), that is,
Further screwing is performed so as to move to the rear end side in the direction of the axis O.

Then, the tip side portion 1 of the pull-in bolt 120
The wall surface 127 of the concave portion 125 formed in 22 facing the rear end side in the direction of the axis O is the axis O in the fitting portion 160 of the retracting member 150 into which the tip side portion 122 is fitted.
The wall surface 166 facing the front end side in the direction is generally pressed toward the rear end side in the direction of the axis O, and the retracting member 150 causes the tool body 1 to move.
It is drawn toward the rear end side in the direction of the axis O with respect to 10.

In this way, when the retracting member 150 is retracted toward the rear end side in the direction of the axis O, the retracting member 150 is passed through the hook hole 154 formed in the retracting member 150 and is inserted into the hook portion accommodating hole 155. The wall surface 140 of the end portion 136 of the hook portion 134, which is in the accommodated state, facing the front end side in the axis O direction is the wall surface 159 located around the hook hole 154 and facing the rear end side in the axis O direction. By contacting each other, relative movement of the blade portion 130 and the retracting member 150 in the direction of separating from each other in the direction of the axis O is blocked, and the blade portion 130 and the retracting member 150 are connected.

As it is, the through hole 11 of the lead-in bolt 120.
By continuing to screw in 7, the pull-in member 150
By further pulling the blades into the mounting hole 112 toward the rear end side in the axis O direction, the blade portion 130 connected to the pulling member 150 and prevented from moving relative to each other in the axis O direction is also a tool. The blade portion 130 is drawn toward the rear end side in the axis O direction in the mounting hole 112 with respect to the main body 110.
The outer peripheral surface of the tapered portion 132 presses the inner peripheral surface of the tapered hole 113 of the mounting hole 112, and the blade portion 130 is attached to the tool body 110 and is detachably fixed.

On the other hand, in the step of removing the blade portion 130 from the tool body 110, first, the through hole 1 of the tool body 110
Loosen the pull-in bolt 120 screwed in 17 so that the pull-in bolt 120 moves to the other direction side in the axis P direction (upper left direction in FIG. 1), that is, to move to the tip side in the axis O direction. Go (screw in).

Then, the tip side portion 1 of the pull-in bolt 120
The wall surface 128 of the concave portion 125 formed in 22 facing the front end side in the axis O direction is the axial O direction in the convex portion 163 formed in the fitting portion 160 of the retracting member 150 with which the front end portion 122 is fitted. Wall surface 165 facing the rear end side
Is pushed toward the tip side in the axis O direction, and the retracting member 150 is pushed toward the tip side in the axis O direction with respect to the tool body 110.

In this way, when the retracting member 150 is pushed out toward the rear end side in the direction of the axis O, the retracting member 15
Axis O located around the hook hole 154 formed in 0
Wall surface 159 facing the rear end side in the direction, and wall surface 140 facing the front end side in the direction of the axis O in the end portion 136 of the hook portion 134 of the blade portion 130 that has been in close contact with the wall surface 159.
A gap is created between the taper portion 13 and the blade portion 130.
The pressing of the mounting hole 112 by the outer peripheral surface of No. 2 against the inner peripheral surface of the tapered hole 113 is released.

Further, as the retracting member 150 is pushed out toward the tip side in the direction of the axis O, the hook portion accommodating hole 15 is formed.
5 bottom surface 155A (wall surface facing the tip side in the direction of the axis O)
And the distance between the end surface 137 of the end 136 of the hook portion 134 accommodated in the hook portion accommodation hole 155 is gradually reduced, and finally the bottom surface 1 of the hook portion accommodation hole 155 is obtained.
55A comes into contact with the end surface 137 of the end portion 136 of the hook portion 134 and presses it toward the tip side in the direction of the axis O, so that the blade portion 130
Are extruded toward the tip side in the direction of the axis O.

The key grooves 141A and 141B formed on the wall surface 131A of the cutting portion 131 of the blade portion 130 facing the rear end side in the direction of the axis O and the keys 119A and 119B formed on the tip surface 111 of the tool body 110. Until the fitting is released, the blade portion 130 is pushed toward the tip side in the axis O direction with respect to the tool body 110, and then the blade portion 130 and the retracting member 150 are circumferentially separated by a predetermined angle (the first embodiment). When rotated relative to each other by about 60 ° in the form, the blade portion 130
And the retracting member 150 are in phase with each other.

As a result, the hook portion 134 of the blade portion 130 is formed.
It becomes possible to pull out the end portion 136 of the tool from the hook hole 154 of the retracting member 150, and the blade portion 130 is moved to the tool body 11
Can be removed from scratch.

In the blade-interchangeable cutting tool 100 having such a structure, the rear end side of the tool body 110 is attached to the rotary shaft of the machine tool and rotated about the axis O, so that the blade portion 130 is rotated. The work is cut by the cutting edge formed in the cutting portion 131.

In the blade-interchangeable cutting tool 100 according to the present embodiment configured as described above, the pulling-out bolt 120 pushes the pull-in bolt 120 toward the axial line P of the through-hole 117 in the axial direction P ( The other side of the longitudinal direction (Fig. 1
Upper left direction), that is, by loosening the lead-in bolt 120 so as to move to the tip side in the direction of the axis O, the recess 125 of the tip-side portion 122 of the lead-in bolt 120.
At the wall surface 128 facing the tip end side in the direction of the axis O in the axis O of the projection 163 of the fitting portion 160 of the retracting member 150.
This is performed by pressing the wall surface 165 facing the rear end side in the direction. Therefore, in the step of removing the blade portion 130, the retracting member 150 connected to the blade portion 130 is pushed toward the tip side in the axis O direction with sufficient pushing force toward the tip side in the axis O direction. This makes it possible to smoothly perform the step of removing the blade portion 130.

Moreover, the leading end portion 120 of the lead-in bolt 1
22 and the fitting portion 160 of the pull-in member 150, the pull-in bolt 120 is screwed into the through hole 117 and the pull-in member 150 is inserted into the mounting hole 112 at the same time, so that the pull-in bolt 120 can be inserted. Since the tip end side portion 122 and the fitting portion 160 of the retracting portion 150 can be fitted to each other by fitting the concave portion 125 and the convex portion 163 formed therein, the pull-in bolt can be mounted as in the conventional case. It is not necessary to combine a plurality of parts, the cost can be suppressed without increasing the number of parts, and the blade-interchangeable cutting tool 100 itself can be easily downsized.

Further, the rear end side portion 133 of the blade portion 130 and the retracting member 150 are detachably connected, and this retracting member 150 constitutes the retracting portion of the blade portion 130 and the front end portion 122 of the retracting bolt 120. Since it has the fitting portion 160 into which the fitting portion 160 is fitted, it is not necessary to unnecessarily increase the size of the blade portion 130 in order to form the fitting portion 160 on the blade portion 130, and moreover, in the direction of the axis O. Therefore, the pressing force of the pull-in bolt 120 screwed in the inclined direction does not directly act on the blade portion 130.

When the blade portion 130 is mounted on the tool body 110, the taper portion 1 of the blade portion 130 is
Since the outer peripheral surface of 32 presses the inner peripheral surface of the tapered hole 113 of the mounting hole 112, the drawing member 150 allows the blade portion 13 to be pressed.
When 0 is pulled to the rear end side in the axis O direction, the pull-in member 150 forms the pull-in portion of the blade portion 130 as described above, and the pressing by the pull-in bolt 120 does not directly act on the blade portion 130. , The end 136 of the hook portion 134 moves the axis O about n times (n ≧ 2, n in the first embodiment).
= 3), which is rotationally symmetrical, the force when the retracting member 150 retracts the blade portion 130 to the rear end side in the axis O direction can be along the axis O direction.

As a result, the tapered portion 132 of the blade portion 130 is formed.
The outer peripheral surface of the tool body 11 has a uniform and uniform force for pressing the inner peripheral surface of the tapered hole 113 of the mounting hole 112.
Since the eccentricity of the blade portion 130 with respect to 0 is not caused and the axis O of the blade portion 130 and the axis O of the tool body 110 are perfectly aligned and centered, in a cutting process that requires high accuracy. Can be sufficiently dealt with, and a good dynamic balance can be obtained.

Further, as described above, the outer peripheral surface of the tapered portion 132 of the blade portion 130 presses the inner peripheral surface of the tapered hole 113 of the mounting hole 112, and the taper angle θ at one side of the tapered portion 132 is , 2 to 25 °, the outer peripheral surface of the tapered portion 132 and the mounting hole 11
A proper pressing force is generated between the inner peripheral surface of the second tapered hole 113 and the tapered portion 132 of the blade portion 130 can be firmly tightened by the tapered hole 113 of the mounting hole 112. The rigidity can be kept high. Even though the blade portion 130 is firmly tightened as described above, when the blade portion 130 is detached from the tool body 110, the pulling member 120 and the blade portion 130 are securely attached to each other by a sufficient pushing force given by the pulling bolt 120. The blade can be pushed out, and it does not hinder the smooth removal of the blade.

Here, when the taper angle θ of the tapered portion 132 of the blade portion 130 becomes smaller than 2 °, the pressing force generated between the outer peripheral surface of the tapered portion 132 and the inner peripheral surface of the tapered hole 113 (due to the wedge effect). ) Too high, tapered hole 11
3 is expanded due to elastic deformation. Therefore, even when the blade portion 130 is not pulled in by the retracting member 150, the tapered portion 132 is tightened by the elastic force of the tapered hole 113, and the blade portion 130 is fixed to the tool body 1.
There is a risk that it will not come off from 10. On the contrary, even if the taper angle θ is larger than 25 °, the pressing force may be small and the blade portion 130 may not be held sufficiently.

Further, the leading end side portion 12 of the pull-in bolt 120
2 and the fitting portion 160 of the pull-in member 150 are fitted to each other, the wall surface of the fitting portion 160 of the pull-in member 150 facing the circumferential direction is the tip side portion 12 of the pull-in bolt 120.
Since the relative rotation of the retracting member 150 with respect to the tool main body 110 in the circumferential direction is prevented by being arranged so as to face the outer peripheral surface of the second concave portion 125 and the curved surface 126 of the concave portion 125 and abut against each other, the connection as described above. Even with the blade portion 130 and the retracting member 150 having the structure, the connection state between them is not adversely affected, and the stable mounting state of the blade portion 130 can be maintained.

In addition, when the blade portion 130 is mounted on the tool body 110, the pair of key grooves 141A and 141B and the pair of keys 141A and 141B are fitted to each other, and the blade portion 130 is attached to the tool body 110. Since the relative rotation in the circumferential direction is blocked, the blade portion 130 is attached to the tool body 1
When the blade portion 130 is mounted on the blade 10, the blade portion 130 can be easily positioned in the circumferential direction, so that the operability can be improved.

In particular, the pair of keyways 141A and 141B
Has a different size, and the pair of keys 119A and 119B have different sizes. Therefore, when the blade portion 130 is rotated relative to the tool body 110 by 180 ° in the circumferential direction, these keys are Groove 141
Since the A and 141B and the keys 119A and 119B cannot be fitted to each other, the operability can be further improved. The keyways 141A, 141
B is formed on the tip surface 111 of the tool body 110, and the keys 119A and 119B are the cutting portions 1 of the blade portion 130.
It may be formed on the wall surface 131 </ b> A facing the rear end side in the axis O direction of 31.

Further, in the present embodiment, the tool body 1
The through hole 117 formed in 10 is inclined with respect to the axis O direction toward the rear end side in the axis O direction as it goes radially inward, but conversely, the through hole 117 is formed.
May be inclined with respect to the axis O direction so as to be directed toward the tip end side in the axis O direction according to the radially inward direction.

Further, in the present embodiment, the recess 125 is formed in the front end side portion 122 of the retractable bolt 120 so that the outer diameter of the front end side portion 122 is reduced by one step, and the retractable bolt 120 is connected to the retractable member 150. Recess 125
Although the fitting portion 160 having the convex portion 163 corresponding to is formed, conversely, the tip side portion 122 of the retractable bolt 120 is formed.
A convex portion is formed on the tip end side portion 122 so that the outer diameter of the tip end side portion 122 is further increased.
A fitting portion having a concave portion corresponding to the convex portion of 0 may be formed.

Further, in the present embodiment, the blade portion 13
0 and the retracting member 150 are connected by forming the hook portion 134 in the rear end side portion 133 of the blade portion 130 and forming the hook hole 154 in the retracting member 150, but the invention is not limited to this. Without being concerned, there is no question about the connection configuration between the blade portion 130 and the retracting member 150. In addition,
In the present embodiment, the rear end side portion 133 of the blade portion 130
By detachably connecting the retracting member 150 and the retracting member 150,
Although the retracting member 150 is used as the retracting portion of the blade portion 130, the invention is not limited to this, and it is conceivable that the fitting portion is directly formed on the rear end side portion of the blade portion 130.

[0083]

EFFECTS OF THE INVENTION According to the blade portion exchangeable cutting tool of the present invention,
When removing the blade from the tool body, screw the loosening bolt toward the other side of the through-hole in the longitudinal direction to loosen it so that the axial tip of the concave portion or convex portion of the leading end portion of the deepening bolt is in the axial direction. The wall surface facing the side abuts against the wall surface facing the rear end side in the axial direction of the convex portion or the concave portion of the fitting portion of the retracted portion to press the retracted portion toward the distal end side in the axial direction. It can be pushed out with a pushing force, and the blade part removal process can be performed smoothly. Moreover, when the leading end side portion of the retractable bolt and the fitting portion of the retracted portion are fitted to each other, the retractable bolt is screwed into the through hole and the retracted portion is inserted into the mounting hole at the same time. Since the tip end side portion and the fitting portion of the retracting portion can be fitted to each other by fitting the concave portion and the convex portion formed therein, as in the conventional case, the pulling bolt can be formed into a plurality of members. It is no longer necessary to combine the two with each other, the number of parts does not increase, the cost is suppressed, and the size can be easily reduced.

[Brief description of drawings]

FIG. 1 is a sectional side view of a blade-interchangeable cutting tool according to an embodiment of the present invention.

FIG. 2 (a) is a side view showing a tool body of a blade-interchangeable cutting tool according to an embodiment of the present invention, and FIG. 2 (b) is a front end view of the tool body.

FIG. 3A is a side view showing a blade of a blade-interchangeable cutting tool according to an embodiment of the present invention, and FIG. 3B is a rear end view of the blade.

FIG. 4 (a) is a perspective view showing a retracting member of the blade-interchangeable cutting tool according to the embodiment of the present invention, FIG. 4 (b) is a plan view of the retracting member, and FIG. Line cross section,
(D) It is a front view of the retracting member.

FIG. 5A is a sectional perspective view showing an example of a conventional blade-interchangeable cutting tool, and FIG. 5B is an exploded sectional view for explaining the blade-interchangeable cutting tool.

[Explanation of symbols]

100 exchangeable cutting tools 110 Tool body 112 mounting holes 113 taper hole 117 Through hole 120 retract bolt 122 Tip part 125 recess 130 blade 132 taper 150 Retractable member (retracted part) 160 Fitting part 163 convex O Tool body axis P Through hole axis

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toru Nakamura             1511 Furumagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture             Mitsubishi Materials Corporation Tsukuba Works F-term (reference) 3C022 FF01                 3C037 BB16

Claims (4)

[Claims] 1. A retracting portion of a blade portion having a cutting portion having at least one cutting blade is inserted into a mounting hole formed in a tool body, and the retracting portion is arranged in an axial direction of the tool body. A blade-interchangeable cutting tool in which the blade portion having this retracted portion is retractably attached to the rear end side in the axial direction of the tool body by being retracted to the rear end side, The main body is formed with a through hole penetrating from the outer peripheral surface to the mounting hole in a direction inclined with respect to the axial direction. A pull-in bolt having a convex portion with a large outer diameter is screwed in, and the outer peripheral surface of the pull-in portion is cut out to correspond to the concave portion of the pull-in bolt or the convex portion of the pull-in bolt. A fitting portion having a concave portion is formed, and the tip end side portion of the pull-in bolt and the fitting portion of the pull-in portion are fitted to each other so that the concave portion and the convex portion formed therein are fitted with each other. And, by screwing the pull-in bolt so as to move in one direction side in the longitudinal direction of the through hole, a wall surface of the recess or protrusion of the draw-in bolt that faces the rear end side in the axial direction is a protrusion of the pull-in portion. Of the recess or the recess in the longitudinal direction of the through hole while the retracting portion is retracted to the rear end side in the axial direction while abutting against and pressing the wall surface facing the tip side in the axial direction. The wall surface of the concave portion or convex portion of the pull-in bolt facing the tip end side in the axial direction of the concave portion or convex portion of the pull-in bolt has a convex portion or a concave portion of the pull-in portion. Wherein the wall surface facing the rear side in the axial direction abuts to press it, the blade portion replaceable cutting tool, wherein the pull portion is pushed out to the tip side of the axially definitive. 2. The blade-interchangeable cutting tool according to claim 1, wherein the retraction portion of the blade portion is a retraction member removably coupled to a rear end side portion of the blade portion, The blade portion and the retracting member are inserted into the mounting hole, and the retracting member is retracted toward the rear end side in the axial direction of the tool body, so that the blade portion connected to the retracting member is the tool. A blade-interchangeable cutting tool that is detachably attached by being pulled in to the rear end side in the axial direction of the main body. 3. The blade-interchangeable cutting tool according to claim 1, wherein the blade has a substantially frustoconical tapered portion whose outer diameter gradually decreases toward the rear end side. The mounting hole has a tapered hole in the shape of a truncated cone whose inner diameter gradually decreases toward the rear end side, and the outer peripheral surface of the tapered portion of the blade portion has a taper of the mounting hole. A blade portion exchangeable cutting tool, wherein the blade portion is detachably mounted by pressing the inner peripheral surface of the hole. 4. The blade-interchangeable cutting tool according to claim 1, wherein the fitting portion of the retracting portion includes a wall surface facing the circumferential direction of the tool body, When the tip end side portion of the draw-in bolt and the fitting portion of the draw-in portion are fitted to each other, the outer peripheral surface at the tip-end side portion of the draw-in bolt and the wall surface facing the circumferential direction at the fit-in portion of the draw-in portion are A blade-interchangeable cutting tool, which is arranged so as to face each other and prevents relative rotation of the retracted portion with respect to the tool body in the circumferential direction.