Replaceable head cutting tool

Technical Field

This invention involves a kind of such as a seat for the edge of the cutting head and cutting head is connected and to maintain the head of the cutter seat, and the like more replaceable cutting tool.

Background Art

As this kind of head replaceable cutting tool, in Patent document 1 there is a recorded in the replaceable cutting head, to be inserted into a seat formed in the knife and the mounting hole in the mounting thread a spiral is solid , this is mounted to the loading and unloading, the replaceable cutting head a by the following structure: the cutting head body, is composed of a hard material, and the edge at the front end part of the set, is arranged in the rear end part and is inserted into the mounting hole of the mounting part in, and has a recess in the inner peripheral surface of the connecting hole; and coupling member, than the above-mentioned hard material having a hardness of the low hardness of a metal material, and is inserted into the above-mentioned linking hole and the outer peripheral surface and inner peripheral surface so as to be matched to the front end of the shaft part, and the above-mentioned installation of the threaded part of the head of the screw threaded portion, and in the above-mentioned head screw thread portion and the front end of the front end of the shaft in order to move along the inside of the center line of the shaft hole is formed in a manner, the coupling member is connected to the cutting head body.

This replaceable cutting head, the front end of the connecting part of the shaft part is inserted into the cutting head after connecting hole of the main body, to the connecting part is pressed into the fastening hole of slightly more than the inner diameter of the outer diameter of the punch, the connecting part by the plastic deformation of the front end of the shaft expanding the same, and to make the outer peripheral surface of the connecting hole and the inner peripheral surface of the recess, whereby the cutting head body and a coupling member as a whole. In this, in the Patent document 1 in the cutting head with connecting hole of the main body is formed as a ring-shaped groove and the inner peripheral surface of the recess the technical, in addition, in Patent literature 1 of Figure 3 in, along the above-mentioned central line in the recess, on the section of the roughly in the shape of a circular arc shape.

Patent literature 1: Japanese Patent discloses 2011-143532, the

However, if it is this kind of cross section of the recess is of an arc shape, in order to improve the cutting head main body and the coupling member the matching strength, the front end of the connection part to the outer peripheral surface of the shaft the greater the amplitude of the increase in the recess of the recess when the width of the above-mentioned center line direction, will increase in the depth of the recesses, and the punch is pressed into the connecting part thread portion is screwed into the head of the mounting screw to the blade holder, or so installed on the cutter seat and replaceable cutting head used for the cutting of the cutting load, such as play a role, in the material is hard and brittle trend is also a relatively high cutting head body from the bottom of the recess to produce rhagadia, broken longitudunal.

On the other hand, if the depth of the recess is kept unchanged and form elongated circular arc the center line direction of the long section for half of the length of the recess of the round, the outer peripheral surface of the shaft at the front end of the plastic deformation amount is increased, but the punch is pressed into the connecting part when the shaft portion at the front end of the plastic deformation, the plastic deformation by a wide margin the outer peripheral surface of the shaft at the front end of the over-is firmly clamped in the recess side wall of the pressing-in direction, is applied to the punch is pressed into the direction of the rear side of the large load, there is danger of impairment of the punch. And, connecting hole of the body of the cutting head along the center line direction of the inner peripheral surface is significantly cut, the cutting head main body there are still the intensity of the danger of damage and damage.

Content of the invention

The invention is in this context that the completed, aims to provide a the same will not produce the material is hard and brittle trend is also strong and the shell of the head body of the tool body, such as the breakage of the damage and punch, and can improve the tool main body and the connecting part of the head of the fitting strength of the replaceable cutting tool.

In order to solve the above problem and to achieve this kind of purpose, the head of this invention in the replaceable cutting tool, will be low in hardness than the hard material of the metallic material of the cylindrical connection member is inserted into the mounting part, by the above-mentioned hard material formed in a main body of the tool has a concave part on the inner peripheral surface of the mounting hole, the mounting part with the expanding manner to the plastic deformation of the mounting portion and the outer peripheral surface of the inner peripheral surface of the mounting hole and with the above-mentioned recess, thereby making the above-mentioned tool main body and the above-mentioned linking member engages, wherein with the above-mentioned concave recess: section 1 the wall surface, toward the above-mentioned mounting part with inserted into the mounting hole and the insertion direction side toward the outer circumferential side; and 2 wall, and the section 1 towards the wall face of the insertion direction thereof and with the side and towards the inner peripheral side, in the above-mentioned paragraph 1 of the above-mentioned wall surface and the inner peripheral surface of the mounting hole of the above-mentioned on the cross position of the section 1 with the surface of the wall is perpendicular to the center line of the mounting hole formed by the plane of the section 1 is smaller than the inclination angle is set in the above-mentioned paragraph 2 of the above-mentioned wall surface and the inner peripheral surface of the mounting hole of the above-mentioned on the cross position of the section 2 with the above-mentioned surface of the wall of the vertical central line of the plane of the section formed by the 2 inclination angle.

The replaceable cutting tool head, the tool mounting portion is inserted in the mounting hole of the main body into the insertion direction of the connecting part to the mounting part when the diameter of the punch head of a plastic deformation of the press-in direction, but towards the insertion direction with the side facing the insertion direction and toward the outer peripheral side of the section of the recess 1 to the wall surface of the installation hole of the center line of the section 1 is smaller than the inclination angle is set to the section 1 towards the wall face of the insertion direction side of the drilling but toward the inner circumferential side of the section 2 with respect to the above-mentioned plane of the wall surface of the section 2 tilt angle, relative to the center line of the mounting hole or the inner peripheral surface of the case of the angle of incidence of the formed by the, section 2 is less than the wall section 1 wall.

Therefore, if the section 1 and the wall surface of the inner peripheral surface of the mounting hole on the cross position of the section 1 with the surface of the wall of the mounting hole is perpendicular to the center line of the section of the plane of the 1 angle of incidence with the Patent literature 1 is recorded in the head of the recess of the cutting tool, and replacing the same, even if the depth of the recesses is the same, because the section 2 formed by the wall surface of the the slope of the line is relatively slow, the center line of the recess can also be correspondingly increasing width in the direction of, so as to increase when the punch is pressed into the outer peripheral surface of the mounting part of the plastic deformation amount. And, as with the recess portion is a semi-cross-section compared with situations such as a long round, also can reduce the part of the tool main body is cut.

Furthermore, located in the direction of the side of the punch press in section 2 as described above with respect to the mounting hole wall in the inner peripheral surface of the inclined relatively slow, this will not take place by the plastic deformation of the outer peripheral surface of the mounting region of excessive firmly lock the section 2 of the wall, can be pressed in the direction of the applied to the punch to the rear side of the load is relatively small to prevent punch produce damage. Moreover, with respect to the section 2 the wall surface, the mounting portion is inserted into the mounting hole in the rear section of the insertion direction of the 1 wall surface of the center line of the mounting hole and the inner peripheral surface of the steeper inclined, therefore can be firmly locked at substantially the outer peripheral surface of the mounting portion of the plastic deformation and improve the matching strength, thus can make the drawing relative to the resistance of the connecting part of the enhanced.

In this, the above-mentioned paragraph 2 inclination angle is preferably set to 45° or more. If the section 2 inclination angle of less than 45 °, subsection 2 wall surface of the mounting hole or the inner peripheral surface of the center line of the steeper the slope of the, pressed into the mounting portion of the plastic deformation of the punch head the circumference surface card stops of the section 2 stops the strength of the wall is too strong and reliably preventing the punch is no danger of damage. However, because the section 2 toward the mounting portion with the wall surface of the inserted into the mounting hole and the insertion direction side towards the inner circumferential side, therefore section 2 inclination angle does not exceed 90°.

Furthermore, section 2 wall can be as follows: along the center line of the mounting hole and is in a linear-shaped cross section of the cross the inner peripheral surface of the mounting hole, but can also be in this section to the above-mentioned on the inner circumferential side of the mounting hole proeminent raised tune linear. In this case, can further reduce the installation of the plastic deformation of the outer peripheral surface.

And, the above-mentioned paragraph 1 inclination angle is preferably set as 45° the following. If the section 1 tilt angle is increased to more than 45 °, relative to the center line of the mounting hole and the inner peripheral surface of the reduced inclination excessive, could not be reliably improve the matching strength longitudunal. However, because the section 1 with the wall surface of the mounting portion is inserted into the mounting hole and the insertion direction side toward the outer circumferential side, therefore section 1 inclination angle of no less than 0° and become negative, that is, section 1 will not be in the wall of the mounting hole on the inner peripheral surface of the the cross position of the side towards the above-mentioned insertion direction and towards the inner circumferential side.

As explained above, according to the present invention, can prevent the damage of the tool main body and such as the breakage of the punch press, at the same time improve the tool main body and the connecting component the matching strength, and can reliably prevent the coupling member from the tool main body is drawing.

Description of drawings

Figure 1 is a side view of the invention of the head main body of the embodiment.

Figure 2 is an elevational view of the embodiment shown in Figure 1.

Figure 3 is a side view of a manufacturing 1 of the embodiment shown in the head the head of the main body the main raw material.

Figure 4 is a cross-sectional view of the head main body is the raw material is shown in Figure 3.

Figure 5 is a side view of the partial sectioning the connecting member is inserted to the Figure 1 is shown in the head body of the raw material and the plastic deformation of the punch.

Figure 6 is the amplifying a cross-sectional view of the recess of the embodiment shown in Figure 1.

Figure 7 is enlarged a cross-sectional view of said Figure 6 the deformation of the concave recess of the shown embodiment.

Note the Figure mark

1-the head main body (tool body), 1A-head the main raw material, 2-coupling member, 11-edge, 12-engaging part, 13-conical shaft, 16-mounting hole, 17-annular groove (recess), 17a-section 1 wall, 17b-section 2 wall, 21-mounting portion, 22-external screw thread portion, O-mounting hole 16 of the center line, S-with a plane perpendicular to the center line O, P-punch, F-pressed in the direction (mounting portion 21 is inserted into the mounting hole 16 in the insertion direction of the), w-annular groove 17 (recess) O width in the direction of the center line of the, h-plastic deformation amount, α-1 tilt angle, β-section 2 inclination angle.

Mode of execution

Figure 1 to Figure 6 is graph of the said can be detachably installed on the cutter seat, the head of the milling cutter is established as the structure of the replaceable cutting head of the cutting tool of the invention in one embodiment. As shown in Figure 1, the cutting head in the head main body 1 engaging on the coupling member 2, the head main body 1 as a hard alloy and metal-ceramic, ceramic, and the like are integrally formed of the hard material in this embodiment the tool body, the connecting part 2 forming the head than a hardness of the main body 1 of the above-mentioned hard material such as stainless steel and cast steel and the like, and can be of the plastic deformation of a metal material.

The cutting head of the milling cutter construction establishment such as the latter, via the above-mentioned connecting part 2 with the head main body 1 of the center line O (in this embodiment to the latter a centerline of a mounting hole) become connected with the coaxial way of not illustrated and mounted on the cylinder shaft of the front end of the cutter, the cutter seat is mounted on the main shaft of the lathe head about the center line O and the direction of rotation of the milling cutter rotating T, usually at the same time with the center line O-sent in the direction of, the workpiece by the cutting processing.

As shown in Figure 1, in the head main body 1 is, from the front side (in the Figure 1 to the left) towards the rear end side (in the Figure 1 to the right) are formed in this order: the edge part 11, formed with a cutting edge; engaging part 12, when the replacement of the cutting head with the wrench; and taking a center line O as the center of the truncated cone of the conical shaft section 13, than the outer diameter of the blade portion 11 and engaging part 12 is smaller, and as the outer diameter gradually decreases toward the rear end side. Furthermore, the conical shaft section 13 to the periphery surface of the angle of inclination of the central line O imaged by the preferably 1 °-20 ° in the range of, more preferably is provided at 1 °-5 ° in the range of, further preferably is provided at 1 °-3 ° in the range of, in this embodiment is set to 2°.

The edge part 11 along the circumferential direction of the outer periphery of the formed by a plurality of (in this embodiment is 4 bar) flutes 14, the flutes 14 from the head main body 1 towards the rear end side of the front end of the head of the milling cutter about the axis O T the rear side of the rotation direction of the spiral, in these flutes 14 formed with the side of the periphery of the edge circumference edge 15a as the above-mentioned cutting edge, in the front-end side of the same edge and formed with a bottom edge 15b as a cutting edge. Furthermore, the embodiment of a vertical milling cutter is radius end mill, in these circumference edge 15a and bottom edge 15b cross-cutter head formed with a circular arc part is 1/4 of the arc and arc-blade cutter head linear raised tune 15c, therefore by these circumference edge 15a, bottom sunblade 15b and bit arc-blade 15c form a plurality of (4 bar) cutting edge formed on the head main body 1 is.

Figure 3 and Figure 4 is the head the main raw material 1A, as shown in Figure of said such as forming the flutes 14 and circumference edge 15a, bottom sunblade 15b and bit arc-blade 15c before the head main body of the 1 head of raw materials of the main raw material 1A plan, of the hard material in the sintering of the as described above is produced, such as 5 shown, is inserted into the coupling member 2 and after joint, forming edge 11 of the flutes 14 and circumference edge 15a, bottom sunblade 15b and bit arc-blade 15c, so as to make the head main body 1. Furthermore, in fig. 3 to fig. 5 in, by way of illustration, in the head the main raw material 1A to be in the head main body 1 of the blade 11, engaging part 12 and conical shaft 13 is the same as the part of the Figure-mark.

As shown in Figure 4 and Figure 5 shows, in the head the main raw material 1A will be subject to the following on the outside of the recess, the cross section along the center line to center line O to O as the center in a circular way of the inner diameter of the formed with a mounting hole 16, the mounting hole 16 in the conical shaft 13 and the rear end face of the extending end of the forward side of the opening. Furthermore, in the installation hole 16 in the inner peripheral surface of the, as a recess in the this embodiment, as shown in Figure 4, from the conical shaft 13 and the rear mounting hole 16 in order to separate the interval of the interval are respectively formed with a plurality of (in this embodiment 8,) around the central line O surrounding annular groove 17, at least the tip side of the annular groove (in this embodiment a front side of the 2 strip annular groove) 17 O direction of the centre line is formed on the head to the main raw material 1A the head main body is in 1 the matching part of the 12 position.

On the other hand, as shown in Figure 5, coupling member 2 in the front-end side of the center line formed in a roughly cylindrical O as the center of the mounting part 21, and the rear end of the coaxial manner to the side of the formed integrally with diameter than that of the mounting portion 21 of the external screw thread portion 22, mounting portion 21 in the plastic deformation of the outer diameter of the lower slightly smaller than the state before the mounting hole 16 of the inner diameter, and, the male screw section 22 is set to larger than the outer diameter of the mounting hole 16 and smaller than the inner diameter of the conical portion 13 of the outer diameter of the rear end. Furthermore, the external screw thread portion 22 to the directions of spiral of the milling cutter above stands T in the direction opposite to the rotation direction.

And, a cylindrical mounting part 21 through the inner periphery of the threaded part 22 of the connecting member and 2 the rear end face of the opening. However, the coupling member 2 the inner peripheral part at least in fig. 5 shown in the state before the plastic deformation of the lower, in the above-mentioned mounting part 21 part, is of the groove is set smaller than the inner diameter of the threaded part 22 part more small. And, as shown in Figure 5, mounting portion 21 in the direction of the axis O is set to a ratio of the length of the mounting hole 16 in the short but the depth of the threaded part 22 with the front end of the conical shaft section 13 is connected with the rear end face of the block is more than under the state of the front ends of the annular groove 17 of the length.

On the mounting portion 21 is inserted in the header the main raw material 1A in the installation hole 16 as described above in the outer threaded portion 22 and the front end of the shaft 13 against the back end face of the state, as shown in Figure 5 is shown the arrowhead in the line, the punch P and the connecting member 2 is inserted into the mounting hole 16 is inserted in the same direction as the direction of press F are pressed into the this kind of coupling member 2 the inner peripheral part, the mounting portion 21 is plastically deformed in a manner to enlarge the mounting portion 21 with the outer peripheral surface of the mounting hole 16 to the inner peripheral surface of the, in the above-mentioned ring-shaped groove as a recess 17 on the position, as shown in Figure 6 is shown by a dashed line in the outer peripheral surface into the annular groove 17 and fitting, thus engaging the head and is arranged on the main raw material 1A the upper.

In this, in this embodiment, a punch P is higher than the connecting part 2 and a hardness of the head main body 1 the following hardness of the hardness of the tool steel and, for example, formed metal materials such as bearing steel, it also can be used with the head main body 1 likewise is composed of a hard alloy or metal-ceramic, ceramic, and the like formed of hard material. And, the punch P with the front end part of the cross section of O along the central line of the linear raised tune splenial Q, the pressing part has a Q greater than coupling member 2 before the plastic deformation of the mounting portion 21 of the inner peripheral part is smaller than the inner diameter of the threaded part 22 of the diameter of the inner diameter of the inner peripheral part. The connecting part 2 jointed to the head the main raw material 1A thereafter, punch P from the mounting portion 21 is pulled out of the inner peripheral part.

And, as shown in Figure 6, as mentioned above, by means of plastic deformation of the coupling member 2 a mounting portion 21 of the outer peripheral surface of, the embodiment of the concave recess of the annular groove 17 towards the with the mounting portion 21 is inserted into the mounting hole 16 in the insertion direction of the (former F pressed in the direction of P) toward the side of the outer peripheral side of the section 1 wall 17a, and with the 1 wall surface 17a and as the opposed facing the above-mentioned insertion direction side and toward the inner circumferential side of the section 2 wall 17b, in paragraph 1 wall surface 17a and a mounting hole 16 and the inner peripheral surface of the section on the cross position of the 1 wall 17a relative to the mounting hole 16 O a plane perpendicular to the central line of the imaged S section 1 are similarly set as the inclination angle α is less than in paragraph 2 wall surface 17b and a mounting hole 16 the cross position of the inner peripheral surface of the upper section 2 wall surface 17b of the imaged S relative to the plane of the section 2 inclination angle β.

Furthermore, in this embodiment, these section 1 wall 17a, paragraph 2 wall 17b in on the cross-section of O along the central line is in a linear-shaped and the mounting hole 16 in the inner peripheral surface of the cross, these linear with respect to the above-mentioned plane is set as the angle of the imaged S section 1 inclination angle α, paragraph 2 inclination angle β, and with these linear crossed annular groove 17 the trough bottom 17c in the section of the tangent to the two straight lines and a circular arc concave linear. Section 1 tilt angle α is preferably set as 45° the following, in this embodiment is set to 30 °, and, section 2 is preferably inclined angle β is set to 45° or more, in this embodiment is set to 65°. Of course, section 1 inclination angle α, section 2 will not tilt angle β becomes the 45°.

So, mounting a coupling member 2 in the head the main raw material 1A as mentioned above by forming flutes 14 and circumference edge 15a, bottom sunblade 15b and angle edge 15c into which the head main body 1, the head main body is so manufactured 1 in, coupling member 2 of the male screw portion 22 is screwed into the above-mentioned tool to the formed in the peripheral part in the front end part of the inner screw part, by the matching part 12 with the rear end face of the front end face of the joint, and the tapered shaft section 13 and the outer peripheral surface of the above-mentioned internal thread formed in the front end face of the knife towards the front end side with the between the gradually expanding to the inner peripheral surface of the tapered hole, thereby the knife base is connected with, and used for the cutting processing.

As the above-mentioned structure the replaceable the head of the cutting head of the cutting tool, as a ring-shaped groove of the recess 17 of the section 1 wall 17a with respect to a plane perpendicular to the center line O S section 1 inclination angle α less than 2 wall 17b S relative to the plane of the section 2 inclination angle β, on the contrary, with respect to the center line O and the on the central line O which extends parallel to the installation hole 16 in the inner peripheral surface of the case of the angle of incidence of, section 2 wall 17b less than 1 wall 17a. Therefore, even if not deepened annular groove 17 depth, as shown in Figure 6, it is possible to increase the annular groove 17 the width of the central line O direction w, and can increase the punch P is pressed into the connecting part 2 of the mounting portion 21 of the plastic deformation of the mounting portion 21 enters the outer peripheral surface of the annular groove 17 h the amount of plastic deformation of the.

Moreover, in so the greater the amount of plastic deformation of the mounting part to enter h 21 of an outer circumferential surface of the annular groove 17 in the direction of the above-mentioned press (mounting portion 21 is inserted into the mounting hole 16 in the insertion direction of the) F rear side, relative to the mounting hole is formed 16 steeper the inner peripheral surface of the section of the angle of incidence of the 1 wall 17a, are therefore able, through section 1 wall 17a so that the substantially into the annular groove 17 in the installation part 17 to the outer peripheral surface of the firm the card stops with increased intensity, as described above with respect to the to the drawing and is arranged on the knife seat and use for cutting machining of the coupling member 2 in the direction of the load, higher resistance can be obtained.

And, even if not deepened annular groove 17 is also able to increase width w, is thus able to ensure from the annular groove 17 the trough bottom 17c to the head main body 1 until the outer peripheral surface of the wall thickness, and the punch press is arranged on the knife and P the housing or cutting at the time of processing, the alloy is hard and hard material, such as brittle trend is also stronger the head main body 1 and head the main raw material 1A is, from the the bottom of the trench will not also 17c toward the outer peripheral surface of the lead to the creation of cracks and breakage. Furthermore, if the depth of the recesses is the same, and is of the recess portion is a semi-cross-section compared with the case of long round, it is able to reduce the head main body 1 and head the main raw material 1A the mounting hole 16 of the inner peripheral surface of the part is cut to ensure their strength.

On the other hand, is located in the direction of the punch P F side of the press section 2 wall 17b because of its section 2 tilt angle β is set to the greater than section 1 inclination angle with respect to the mounting hole 16 of the inner peripheral surface of a relatively slow, so even if the above mounting portion 21 to the outer peripheral surface of a large plastic deformation amount h into the annular groove 17 the inner, nor will such as section 1 wall 17a firmly as seizing. Therefore, also can prevent the punch P is pressed into the press-in direction to stop the excessive firm F, and its reaction force, applied to the punch P F to the inserting direction of the rear side of the load is too high causing the punch P damage.

Furthermore, in this embodiment, the section 2 wall 17b and 1 wall surface 17a in on the cross-section of O along the central line is also a straight line, but on section 2 wall 17b, as shown in Figure 7 can also be the deformation example, is in this section to the mounting hole 16 of the inner circumferential side of the linear raised tune toward the inserting direction and with the (F pressed in the direction of the) side and toward the inner circumferential side. In the embodiment, the case is set to the section is convex curve section 2 wall surface 17b and the mounting hole 16 a of the angle of the inner peripheral surface of the cross, section 1 inclination angle α of the above-mentioned embodiment are similarly set to 30 °, paragraph 2 tilt angle β is set to 80°.

With this kind of deformation of the annular groove (recess) of the example 17 of the replaceable cutting tool in the head, section 2 wall 17b relative to the mounting hole 16 is inclined toward the inner peripheral surface of the section 2 wall surface 17b and the mounting hole 16 the cross position of the inner peripheral surface of it is gradually retarded, thus can further inhibit plastic deformation of the mounting portion 21 of the outer peripheral surface, but also can further reduce the load of the P the punch. And, the section 2 wall surface 17b is a cross-section compared with the case of a straight line shape, if the annular groove 17 is equal to the depth of (recess), can further reduce the head main body 1 and head the main raw material 1A the part is cut, the strength can be further enhanced.

Furthermore, in order to play these effects, such as the above-mentioned embodiment and its deformation example, section 1 tilt angle α is preferably set as 45° the following, and, section 2 is preferably inclined angle β is set to 45° or more. If section 1 inclination angle α is greater than 45 °, the section 1 wall 17a relative to the mounting hole 16 slow change of inclination of the inner peripheral surface, thereby preventing the plastic deformation of the mounting part 21 and the firm the card stops the outer peripheral surface of the fitting strength, if the article 2 inclination angle β less than 45 °, the section 2 wall 17b relative to the mounting hole 16 excessively steep inclination of the inner peripheral surface, so as to firmly lock the mounting portion 21 is pressed into the outer peripheral surface of the punch P and when the load becomes high.

And, in the above-mentioned embodiment and deformation embodiment, the mounting hole 16 is formed with the inner peripheral surface of the surrounding O around the central line of the annular groove 17 and division section 1 wall 17a, paragraph 2 wall 17b, but also can be cut apart along the circumferential direction 1 or more recess trough achievement. Furthermore, can also be a spiral groove and is not annular groove 17, in this case, the direction of spiral of the plurality of mutually different spiral grooves formed in a crossing pattern form or in a non-crossing manner. And, also can be the trough, but in the mounting holes 16 are dispersed and distributed and the inner peripheral surface of the of the form 1 to one or a plurality of the concave part is formed with the above section 1 the recess 17a, paragraph 2 wall surface 17b of the recess.

On the other hand, in the above-mentioned embodiment and deformation embodiment, the replaceable the head of the head main body of the cutting tool 1 as a tool for the coupling member and engaging the main body 2 by the, but also can the mounting the head main body 1 a of the holder main body is made of hard material as the tool body, and is arranged in the knife holder of the above-mentioned internally threaded portion formed in the coupling member and engaging the knife seat when the body is in the application of this invention. In this case, is inserted into the formed in the holder main body is in a mounting hole of the mounting portion of the connecting part is set to the inner diameter of the inner peripheral part is smaller than the inner diameter of the internal thread, through the punch, and then the punch press P the peripheral part to the mounting part and the mounting part, and the plastic deformation of the coupling member coupled to the knife holder main body.