JP2001062608A - Clamp mechanism of throwaway tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the clamp state of a throwaway tip. SOLUTION: In this clamp mechanism, a bolt hole 31 for string the head of a bolt 26 is formed on the part formed on the thick part of a clamp 22. A receiving surface slanted by a prescribed angle from a horizontal surface is formed in the bolt hole 31 so as to contact with one part of the lower surface of the bolt head. The receives surface of the bolt hole 31 is formed so as to rise and slant toward the cross point V1 of the plane T in parallel with the center axis Q including a straight line L with the outer periphery of the bolt head lower surface from the center axis Q of the bolt 26 relative to the straight line L for connecting a fulcrum β in the clamp mechanism 12 positioning on the axis O of a tool main body 11 at the base of the clamp 22 to an action point γ positioning on the tip center line R on the upper surface of the tip 13 which is a contact point of the pressing part of the clamp 22 with the tip 13 and the cross point V1 of the plane T with the outer periphery of the lower surface of the bolt head is made to a force point α on the clamp mechanism 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp mechanism for a throw-away insert in a throw-away type cutting tool used for cutting such as grooving.

[0002]

2. Description of the Related Art Conventionally, for example, as a cutting tool for performing grooving or parting-off processing on a rotating work, a chip made of a cemented carbide is detachably clamped and held at a tip end portion of a tool body. A throw-away type cutting tool is known. This throw-away type cutting tool is supported by the main spindle of a machine tool such as a lathe or a machining center, and is moved relatively to the workpiece while the throw-away tip is pressed against the workpiece rotating at high speed. Thus, the outer surface and the end surface of the work are cut by the cutting blade formed on the throw-away tip. 6 is a side view of the indexable cutting tool according to an example of the above-described prior art, FIG. 7 is a plan view of the indexable cutting tool shown in FIG. 6, and FIG. 8 is an indexable cutting tool shown in FIG. 9 is a front view of the indexable cutting tool shown in FIG. 6 as viewed from the tip.

In this throw-away type cutting tool 10, a throw-away tip (hereinafter simply referred to as a tip) 13 is attached to and detached from a clamp mechanism 12 provided on the tip side of a tool body 11 gripped by a chuck or the like of a machine tool. It is configured to be clamped and held as possible. The tip 13 is made of, for example, a hard material such as a cemented carbide, and is formed in, for example, a substantially pentagonal prism shape in cross section as shown in FIG.
3, a top surface 14a to be a rake face, and a bottom portion 14 facing the upper surface 14a to form a seating surface.
b, and a side surface 14c formed between the upper surface 14a and the bottom portion 14b. And the upper surface 14a
A cutting edge 15 is formed at the intersection ridge line between the side surface 14c. The bottom portion 14b is formed in a substantially mountain shape in cross section in which the first lower surface 14d and the second lower surface 14e intersect at a substantially obtuse angle. The side surface 14c is inclined outward from the bottom portion 14b toward the upper surface 14a, so that the upper surface 14a to be a rake surface is formed.
The clearance angle is taken to make it a flank. In addition,
As shown in FIG. 7, the chip 13 is formed so as to be symmetrical with respect to the center position in the longitudinal direction,
By changing the mounting direction of the clamp mechanism 12, the cutting blades 15 protruding toward the distal end of the tool body 10a among the cutting blades 15 formed at both ends in the longitudinal direction can be replaced and used.

A clamp mechanism 12 for a throw-away tip
Is configured to include a pedestal portion 21 and a clamp portion 22. At the tip of the tool main body 11, one end of both ends in the width direction of the tool main body 11 (direction orthogonal to the axis O). Only from the position offset from the axis O in the width direction so as to protrude toward the tip of the indexable cutting tool 10, that is, with a width smaller than the width of the tool body 11, and to the tip side of the indexable cutting tool 10. It is formed so as to protrude, and is configured to clamp and hold the chip 13 at a position shifted from the axis O. The pedestal portion 21 includes the tool body 11
Is formed in a substantially rectangular plate shape having a width smaller than the width of the tool body 11, and protrudes toward the distal end from one of the two ends that are shifted from the axis O in the width direction at the distal end of the tool body 11. As shown in FIG. 7, the cutting tool 10 is formed so that the vicinity of the distal end of the indexable cutting tool 10 becomes substantially L-shaped in plan view. That is, the base 21 has a shorter length in the width direction (left-right direction in FIG. 9) of the tool main body 11 than the tool main body 11 in a cross-sectional view with respect to the axis O of the tool main body 11 shown in FIG. The length (in the vertical direction in FIG. 9) orthogonal to the axis O and the width direction is shorter than the tool body 11.

Accordingly, as shown in FIG. 6, the pedestal 21 has two pedestal end faces 21 opposed in the longitudinal direction.
A and 21A have one pedestal end face 21A facing the distal end side of the throw-away type cutting tool 10 and the other pedestal end face 21A abutting on the distal end face 11A of the tool body 11. Further, as shown in FIG. 7, of the two pedestal side surfaces 21B, 21B opposed in the width direction of the tool body 11, two pedestal side surfaces 21B, one of which is opposed in the width direction of the tool body 11, One of the side surfaces 11B of the tool body 11B is smoothly connected to one of the side surfaces 11B of the tool body, and the other side surface 21B of the pedestal portion is disposed so as to intersect with the front end surface 11A of the tool body 11. Further, as shown in FIG. 9, of the pedestal portion upper surface 21 </ b> C and the pedestal portion lower surface 21 </ b> D opposed in the direction orthogonal to the axis O and the width direction of the tool main body 11, the pedestal lower surface 21 </ b> D is smooth on the bottom surface 11 </ b> D of the tool main body 11. And the pedestal portion upper surface 21C is connected to the tool body 1
1 and is disposed so as to intersect with the front end face 11A. And
As shown in FIG. 9, a chip mounting seat 23 is formed on the upper surface 21 </ b> C of the pedestal portion.
The seating surface 23a and the second seating surface 23b are formed in a substantially V-shaped cross-sectional groove formed by intersecting the first seating surface 2a.
3a is a first lower surface 14d of the throw-away tip 13,
The second seating surface 23b is configured to abut on the second lower surface 14e. In addition, as shown in FIG. 6, a clearance 23 c is formed on the base end side of the tip mounting seat 23.

As shown in FIG. 7, the clamp portion 22 is formed in a substantially L-shape in plan view, and has a length in the width direction of the tool body 11 that is equal to the length of the tool body 11. An end 22a and a clamp tip 2 having the same length as the pedestal 21 shorter than the tool body 11
2b. The base portion 22a of the clamp portion is arranged so as to face the tip portion of the tool body 11, and the tip portion 22b of the clamp portion is arranged so as to face the pedestal portion 21, respectively. That is, one clamp portion base end side surface 22C of the two clamp portion base end side surfaces 22C and 22C of the clamp portion base end portion 22a opposed in the width direction of the tool main body 11 is located in the width direction of the tool main body 11. One of the two clamp portion tip side surfaces 22D, 22D of the opposing clamp portion tip portion 22b is smoothly connected to one clamp body tip side surface 22D and one tool body side surface 11B of the tool body 11. Clamp tip side 22
D, 22D, the other clamp portion tip side surface 22D
Are arranged to intersect with the clamp portion proximal end surface 22E of the clamp portion proximal end portion 22a. It should be noted that the other clamp portion proximal end side surface 22C of the clamp portion proximal end side surface 22C is connected to the other tool body side surface 1 of the tool body 11.
1B is smoothly connected.

[0007] As shown in FIG.
The base end side of a is connected to the tool main body 11, and a predetermined interval is provided between the lower surface 22A of the base end of the clamp part of the base part 22a of the clamp and the upper surface 11C of the front end of the tool main body 11. In other words, a slit 24 is provided which is cut so as to be substantially parallel to the tip mounting seat 23 from the distal end side to the proximal end side of the tool body 11. Further, the lower surface 22B of the clamp portion distal end portion 22b of the clamp portion distal end portion 22b is provided to be inclined downward (downward in FIG. 6) toward the distal end side from the recess 22d formed on the proximal end side. Then, a tip 1 is attached to the tip of the clamp portion tip lower surface 22B.
For example, a flat pressing portion 25 that presses a substantially intermediate portion of the upper surface 14 a of the chip 3 is provided substantially parallel to the upper surface 14 a of the chip 13. The base portion 22a of the clamp portion is formed to be thick so as to protrude upward (upward in FIG. 6) from the base end side to the distal end side, and the base end side, that is, the base portion of the clamp portion 22 is thin. The flat portion-shaped pressing portion 25 provided at the distal end of the clamp portion distal end portion 22 b is elastically deformed with the base portion as a fulcrum, in a direction approaching the tip mounting seat 23. It is arranged so that it can be displaced.

As shown in FIGS. 6 and 8, a bolt head 26 of the bolt 26 is formed near the axis O of the tool body 11 in a thick portion of the base portion 22a of the clamp portion.
a receiving hole 27a is formed in the bolt hole 27 for contacting the lower surface (contact surface) 26b of the bolt head of the bolt head 26a. A bolt mounting hole 28 into which the screw portion 26 c of the screw 26 is screwed is formed coaxially with the bolt hole 27.
2 through the slit 24 to penetrate the tip of the tool body 11.

Next, a method of mounting the tip 13 on the tool body 11 by the above-described clamp mechanism 12 will be described. First, the bottom portion 14b of the chip 13 is attached to the chip mounting seat 23.
6, and furthermore, as shown in FIG. 6, the side surface 14 c on the proximal end side of the tip 13 is brought into contact with the tip of the tool body 11, so that the tip mounting seat 23 and the pressing portion 25 of the clamp portion 22 are interposed. Position. Then, the bolt 26 is inserted into the bolt hole 27 and the bolt mounting hole 28, and the screw portion 26 c is screwed and tightened into the bolt mounting hole 28, so that the bolt head lower surface 26 is formed.
By pressing the receiving surface 27a of the bolt hole 27 with the b, the chip 13 is pressed toward the chip mounting seat 23 by the pressing portion 25 of the clamp portion 22, and the chip 13 is pressed and fixed.

[0010]

By the way, according to the clamp mechanism 12 of the throw-away tip 13 according to one example of the prior art, the lower surface 26b of the bolt head and the bolt hole 27 are provided.
The lower surface 26b of the bolt head presses against the receiving surface 27a to make contact with the receiving surface 27a provided on the
2 is pressed against the chip mounting seat 23.
7a is applied almost evenly over the entire contact surface with the bolt head lower surface 26b. Therefore, as shown in FIG. 7 and FIG.
The force point for pressing a, that is, the force point α in the clamp mechanism 12 is approximately located on the center axis Q of the bolt 26. Further, as shown in FIGS. 6 and 7, the fulcrum β in the clamp mechanism 12 is approximately located on the axis O near the base of the clamp portion 22, that is, near the base end of the slit 24, and the action point γ is Pressing part 2 of part 22
Located at 5. In this case, in the plan view shown in FIG. 7, the fulcrum β is located on the axis O of the tool body 10 a, the action point γ is a contact point between the pressing portion 25 of the clamp portion 22 and the chip 13, and the upper surface of the chip 13 It will be located on the chip center line R including the center point at 14a and extending along the longitudinal direction. Therefore, the power point α of the clamp mechanism 12 does not lie on a plane parallel to the center axis Q of the bolt 26 and including the straight line L connecting the fulcrum β and the action point γ,
When the screw 6c is screwed and tightened in the bolt mounting hole 28, a torsional moment M around a straight line L as shown in FIG. 9 is generated, and the clamp portion 22 is inclined downward from the straight line L toward the power point α. A torsion with an inclination angle θ occurs with respect to a horizontal plane H orthogonal to the central axis Q.

[0011] Here, the flat-surface-shaped pressing portion 25 is attached to the chip 1.
3 is provided substantially in parallel with the flat upper surface 14a, so that the clamping portion 22
The lowermost portion (lower side in FIG. 9) of the pressing portion 25 is an end portion on the center axis Q side of the bolt 27, and this end portion is in contact with the pressing portion 25 and the upper surface 14a of the chip 13. It becomes the first contact portion ε1. Thus, the first contact portion ε1
Is a position shifted from a chip axis P orthogonal to the chip center line R toward the chip side surface 14c as shown in a cross-sectional view with respect to the chip center line R shown in FIG.
Is located in the vicinity of the intersection ridge line between the upper surface 14a and the chip side surface 14c, and the first contact portion ε1 newly becomes an action point γ in the clamp mechanism 12. Further, the bottom portion 14b of the chip 13 and the chip mounting seat 23 are
The second contact portion ε2 is located at the intersection of the upper surface of the first, ie, the first seating surface 23a and the side surface of the pedestal portion 21, and the third contact portion is located at the intersection ridge portion of the second seating surface 23b and the side surface of the pedestal portion 21. and ε3.

In the indexable cutting tool 10 as described above, it is necessary to suppress chatter (vibration) of the chip 13 due to cutting resistance when cutting the work, and to improve the processing accuracy of the work. Must be firmly fixed to the tool body 11. However,
As described above, the pressing portion 25 of the clamp portion 22 and the tip 1
If the first contact portion ε1 that makes contact with the upper surface 14a of the third member 3 is shifted from the chip axis P, the second and third contact portions ε2 and ε3 are symmetrical with the chip axis P interposed therebetween. Position, the second and third contact portions ε2,
A large imbalance occurs in the resistance acting from the chip mounting seat 23 at ε3, that is, the resistance of the first contact portion ε1 to the force of the pressing portion 25 pressing the upper surface 14a of the chip 13, so that the pressing portion 25 clamps the chip 13. Becomes unstable, and, for example, chatter vibration is likely to occur during processing of the work, and the processing accuracy of the work is reduced. For example, the chip 13 may fall off from the chip mounting seat 23 during cutting. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a clamp mechanism of a throw-away tip which can improve a clamp state of the throw-away tip and can stably fix the tip.

[0013]

In order to solve the above-mentioned problems and to achieve the object, a clamp mechanism of a throw-away tip according to the present invention is provided with a throw-away tip at a tip end of a tool body of a cutting tool. A tip mounting seat for mounting a tip is formed, and a base end side of a clamp portion having a pressing portion for pressing and fixing the throw-away tip at a distal end is connected to the tool body so as to be elastically deformable, and the clamp portion and the A clamping member for displacing the pressing portion toward the chip mounting seat by fastening with a tool body, the clamping portion including a fulcrum when the clamp portion elastically deforms and a center point of the fastening member. A plane parallel to the direction in which the clamp portion is displaced, and the fulcrum and the pressing portion include an action point where the clamp portion is displaced. In a clamp mechanism of a throw-away tip, which intersects with a plane, a force point at which the fastening member presses the clamp portion is disposed on a plane including the fulcrum and the action point and parallel to a direction in which the clamp portion is displaced. It is characterized by being.

According to the throw-away tip clamping mechanism having the above structure, the plane parallel to the direction in which the clamp is displaced, including the fulcrum when the clamp is elastically deformed and the action point where the pressing part presses the throw-away tip. Since the power points at which the fastening member presses the clamp portion are arranged, for example, when a power point is not included in this plane, the generation of a torsional moment generated around a straight line connecting the fulcrum and the action point is reduced. When pressing the clamp portion toward the chip mounting seat by tightening the fastening member, it is possible to prevent the pressing portion of the clamp portion from abutting against the chip mounting seat in a twisted state, and the pressing portion The point where the clamp mechanism contacts with the throw-away tip, that is, the point of action of the clamp mechanism, is shifted to, for example, the end of the throw-away tip. The teeth can be positioned in the vicinity of the center of the throw-away tip. Thereby, it is possible to improve the stability at the time of holding the clamp by pressing the throw-away tip by the pressing portion, for example, chatter vibration is likely to occur at the time of processing the work, and the processing accuracy of the work is reduced, For example, it is possible to prevent the problem that the throw-away tip falls off from the tip mounting seat at the time of cutting.

Further, in the clamp mechanism for a throw-away tip according to the present invention, a receiving surface of the clamp portion that is in contact with the fastening member and pressed by the fastening member is abutting against the fastening member. It is formed so as to be inclined with respect to the contact surface, and a position where the contact surface and the receiving surface contact each other is defined as the force point. According to the clamp mechanism of the throw away tip having the above configuration,
The contact surface of the fastening member comes into point contact with the receiving surface of the clamp portion, and this contact point includes a fulcrum and an action point when the clamp portion is elastically deformed, and is a plane parallel to the direction in which the clamp portion is displaced. , It is possible to improve the stability of pressing and holding the throw-away tip by clamping.

Furthermore, in the clamp mechanism for a throw-away tip according to the present invention, a receiving surface which is in contact with the fastening member and is pressed by the fastening member is formed in the clamp portion. An intermediary member is disposed between the receiving surface and the contact surface of the fastening member, and the intermediary member has an inclined surface that inclines and contacts the receiving surface or the contact surface. The point of contact between the inclined surface and the receiving surface or the contact surface is the force point. According to the clamp mechanism of the throw-away tip having the above configuration, the contact surface of the fastening member or the receiving surface of the clamp portion comes into point contact with the inclined surface of the intermediate member, and this contact point causes the clamp portion to be elastically deformed. Since it is included in the plane parallel to the direction in which the clamp portion is displaced, including the fulcrum and the action point at that time, it is possible to improve the stability when the throw-away tip is pressed and held by the clamp.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a clamp mechanism for a throw-away tip according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view of a throw-away type cutting tool according to an embodiment of the clamp mechanism of a throw-away tip of the present invention, and FIG. 2 is a cross-sectional view of the throw-away type cutting tool shown in FIG. FIG. 3 shows FIG.
FIG. 2 is a front view of the indexable cutting tool shown in FIG. Note that the same reference numerals are assigned to the same parts as those in the above-described conventional technology, and the description will be simplified or omitted. The throw-away type cutting tool 30 including the clamp mechanism of the throw-away tip according to the present embodiment includes a tool body 11, a clamp mechanism 12, and a throw-away tip (chip) 13, and the tip 13 is used. The clamp mechanism 12 for holding the clamp includes a pedestal 21 and a clamp 22.

Here, as shown in FIGS. 1 and 3, a bolt head 26 of the bolt 26 is formed near the axis O of the tool body 11 in a thick portion of the base portion 22a of the clamp portion.
a, and a bolt hole 31 for accommodating the bolt head 31 a is formed in the bolt hole 31.
a predetermined angle δ with respect to the horizontal plane H so as to contact a part of
Receiving surface 31a that is only inclined is formed.
Bolt mounting hole 2 into which screw portion 26c of bolt 26 is screwed
8 is a tool body 1 through the slit 24 from the clamp portion 22 such that the center axis Q of the bolt 26 is orthogonal to the horizontal plane H.
1 is penetrated so as to penetrate. here,
The receiving surface 31a of the bolt hole 31 is formed in a substantially circular shape, and as shown in FIGS.
The fulcrum β in the clamp mechanism 12 located on the axis O of the tool body 11 at the base of the a, and the contact point between the pressing portion 25 of the clamp portion 22 and the chip 13 and the chip center line R on the upper surface 14a of the chip 13 With respect to a straight line L connecting the action point γ located above,
6 in a plane T parallel to the central axis Q of the bolt head lower surface 26.
The force point α of the clamp mechanism 12 formed by the contact between the outer periphery of b and the receiving surface 31a is arranged. That is, the receiving surface 31a is formed so as to be inclined upward from the central axis Q of the bolt 26 toward the power point α of the clamp mechanism 12, and is formed in a direction from the central axis Q of the bolt 26 toward the power point α of the clamp mechanism 12. The end W of 31a is located at the uppermost position (upper side in FIG. 2). In FIG. 1, the outer periphery of the bolt head lower surface 26b and the plane T intersect at two intersections V1 and V2. In this case, the intersection V1 on the action point γ side becomes the power point α of the clamp mechanism 12. Is set to Thus, the power point α, the fulcrum β, and the action point γ of the clamp mechanism 12 are arranged in the same plane T parallel to the displacement direction of the clamp portion 22.

Next, a method of mounting the chip 13 on the tool body 11 by the above-described clamp mechanism 12 will be described. First, the bottom portion 14b of the chip 13 is attached to the chip mounting seat 23.
3, and furthermore, as shown in FIG. 3, the side surface 14 c on the proximal end side of the tip 13 is brought into contact with the tip of the tool body 11, so that the tip mounting seat 23 and the pressing portion 25 of the clamp portion 22 are interposed. Position. Then, the bolt 26 is inserted into the bolt hole 31 and the bolt mounting hole 28, and the screw portion 26 c is screwed and tightened into the bolt mounting hole 28, so that the bolt head lower surface 26 is formed.
By pressing part of the receiving surface 31a of the bolt hole 31 with b, the chip 13 is pressed toward the chip mounting seat 23 by the pressing part 25 of the clamp part 22, and the chip 13 is pressed and fixed. In this case, the power point α of the clamp mechanism 12
Is located in a plane T that includes a straight line L connecting the fulcrum β and the action point γ and is parallel to the displacement direction of the clamp portion 22, and that the screw portion 26 c of the bolt 26 is screwed and tightened into the bolt mounting hole 28. Even if the pressing portion 25 is displaced in a direction approaching the chip mounting seat 23,
No torsional moment is generated around the straight line L connecting the fulcrum β and the action point γ.

As described above, according to the clamp mechanism 30 of the indexable tip according to the present embodiment, the clamp mechanism 22 is located on the plane T that includes the fulcrum β and the action point γ and is parallel to the direction in which the clamp section 22 is displaced. Since the power point α is arranged, for example, when the power point α is not included in the plane T, it is possible to prevent the generation of a torsional moment generated around the straight line L. When pressing against the chip mounting seat 23, the pressing portion 25 of the clamp portion 22 is prevented from abutting against the chip mounting seat 23 in a twisted state,
The first contact portion ε1 between the pressing portion 25 of the clamp portion 22 and the chip 13 can be located on the chip center line R.
Thereby, the stability at the time of pressing and holding the chip 13 by the pressing portion 25 and holding it in a clamp state can be improved. For example, chatter vibration is easily generated at the time of processing the work, and the processing accuracy of the work is reduced. For example, it is possible to prevent the chip 13 from dropping off from the chip mounting seat 23 during cutting.

In the present embodiment, the receiving surface 31a of the bolt hole 31 is formed to be inclined with respect to the horizontal plane H. However, the present invention is not limited to this. As shown in the first modified example of the sectional view taken along the line BB of the away type cutting tool, the horizontal receiving surface 27a
However, an intermediate member such as a washer 32 may be inserted between the lower surface 26b of the bolt head and the receiving surface 27a.
In this case, the washer upper surface (inclined surface) 32 opposed to the washer lower surface 32a that comes into contact with the receiving surface 27a of the bolt hole 27.
b is formed so as to be inclined with respect to the bolt head lower surface 26b, for example, so that the force point α of the clamp mechanism 12 in which the outer periphery of the bolt head lower surface 26b contacts the washer upper surface 32b is located within the plane T. It is good to distribute to. In order to prevent the washer 32 from moving or rotating in the bolt hole 27, for example, an engaging portion (not shown) that locks the inner surface of the bolt hole 27 and the outer surface of the washer 32 in a state where both are positioned. ) May be provided.

In the present embodiment, the pressing portion 25 of the clamp portion 22 is formed as a flat surface. However, the present invention is not limited to this, and the pressing portion 25 according to the present embodiment shown in FIG. As shown in a second modified example of the main part enlarged front view of the throw-away type cutting tool viewed from the tip, a substantially mountain-shaped pressing portion 33 projecting toward the upper surface 14a of the tip 13 as shown in FIG.
May be formed. Here, the pressing portion 33 is formed by intersecting the first pressing surface 33a and the second pressing surface 33b, and the crossing ridge portion of the first and second pressing surfaces 33a, 33b is in contact with the chip axis P of the chip 13. Are to intersect. That is, the first contact portion ε1 at which the pressing portion 25 contacts the upper surface 14a of the chip 13 is set to be located on the chip axis P.

Further, in the present embodiment, the insert 13 has a prism shape of a substantially pentagonal cross section, but the present invention is not limited to this, and the indexable cutting tool according to the present embodiment shown in FIG. As shown in a third modified example of the main part enlarged front view as viewed from the front end, the cross-sectional view is a prismatic throw-away chip 34 having a substantially quadrangular cross-section, and an upper surface 34 a of the chip 34.
Each of the lower surface 34b and the lower surface 34b may be formed in a substantially V-shape in cross-section that is bent toward the inside of the chip 34. In this case, the chip mounting seat 35 is provided between the first seating surface 23a and the second seating surface 23a.
The seating surface 23b may be formed to have a substantially mountain shape in cross section formed by intersecting so as to protrude toward the chip 34. Then, the pressing portion 33 and the tip 34 having a substantially mountain shape in cross section are brought into contact with each other at the two first contact portions ε1, ε1 facing each other at a position symmetrical with respect to the tip axis P on the upper surface 34a of the tip 34, And the second and third contact portions ε2 facing each other at a position symmetrical with respect to the chip axis P on the lower surface 34b of the chip 34.
Contact will occur at ε3.

[0024]

As described above, according to the clamp mechanism of a throw-away tip of the present invention, the generation of a torsional moment generated around a straight line connecting a fulcrum and an action point when the clamp portion is elastically deformed is prevented. The pressing portion of the clamp portion is prevented from coming into contact with the tip mounting seat in a twisted state, and the action point of the clamp mechanism, which is the portion where the pressing portion and the throw away tip come into contact, is set to the throw away tip. In the vicinity of the central portion of Thereby, the stability at the time of pressing and holding the throw-away tip by the pressing portion and holding the clamp can be improved, and for example, it is possible to suppress occurrence of chatter vibration during processing of the work. Further, according to the clamp mechanism of the throw-away tip of the present invention, the contact point between the contact surface of the fastening member and the receiving surface of the clamp portion acts as a fulcrum when the clamp portion is elastically deformed. Since the clamp portion is included in a plane including the points and parallel to the direction in which the clamp portion is displaced, it is possible to improve the stability when the throw-away tip is pressed and held by the clamp. Further, according to the clamp mechanism of the throw-away tip of the present invention, the contact point between the contact surface of the fastening member or the receiving surface of the clamp portion and the inclined surface of the intermediate member is such that the clamp portion is elastically deformed. Since it is included in a plane that includes a fulcrum and an action point when the clamp portion is displaced and that is parallel to the direction in which the clamp portion is displaced, it is possible to improve the stability when the throw-away tip is pressed and held by the clamp.

[Brief description of the drawings]

FIG. 1 is a plan view of a throw-away type cutting tool according to one embodiment of a clamp mechanism of a throw-away insert of the present invention.

FIG. 2 is a cross-sectional view of the indexable cutting tool shown in FIG.
It is a B sectional view.

FIG. 3 is a front view of the indexable cutting tool shown in FIG. 1 as viewed from the tip.

FIG. 4 is a view showing a first modification of the sectional view taken along the line BB of the indexable cutting tool according to the embodiment shown in FIG. 1;

5 (a) is a view showing a second modified example of a main part enlarged front view of the indexable cutting tool according to the present embodiment shown in FIG. 1 viewed from the tip, and FIG. 5 (b) is a view showing FIG. It is a figure which shows the 3rd modification of the principal part enlarged front view which looked at the throw-away type cutting tool which concerns on this embodiment from the front-end | tip.

FIG. 6 is a side view of a throw-away type cutting tool according to an example of the related art.

FIG. 7 is a plan view of the indexable cutting tool shown in FIG. 6;

FIG. 8 is a cross-sectional view of the indexable cutting tool shown in FIG.
FIG. 3 is a sectional view taken along line A.

FIG. 9 is a front view of the indexable cutting tool shown in FIG. 6 as viewed from the tip.

[Explanation of symbols]

 10, 30 throw-away type cutting tool 11 tool body 12 clamp mechanism 13, 34 throw-away tip (tip) 21 pedestal portion 22 clamp portion 23 chip mounting seat 24 slit 25, 33 pressing portion 26 bolt (fastening member) 26b bolt head Lower surface (contact surface) 27, 31 Bolt hole 27a, 31a Receiving surface α Force point β Support point γ Application point M Torsion moment 32b Washer upper surface (inclined surface)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norio Aso 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. F-term in Mitsubishi Materials Corporation Tsukuba Works (reference)

Claims (3)

[Claims] 1. A tip mounting seat for mounting a throw-away tip is formed at a tip of a tool body of a cutting tool, and a base end side of a clamp portion having a pressing portion at a tip for pressing and fixing the throw-away tip is the tool body. And a fastening member for displacing the pressing portion toward the tip mounting seat by fastening the clamp portion and the tool body, and the clamp portion is elastically deformed. A plane parallel to the direction in which the clamp section is displaced, including the fulcrum and the center point of the fastening member, and a direction in which the clamp section is displaced, including an action point where the fulcrum and the pressing section press the throw-away tip. A clamp mechanism for a throw-away tip, which intersects a plane parallel to the plane, wherein the clamp portion is displaced including the fulcrum and the action point. Throw-away tip of the clamping mechanism, characterized in that the fastening member in a plane parallel to the direction is emphasis for pressing are arranged the clamping portion. 2. A receiving surface of the clamp portion, which is in contact with the fastening member and pressed by the fastening member, is formed so as to be inclined with respect to a contact surface of the fastening member. 2. The clamp mechanism for a throw-away tip according to claim 1, wherein a position at which the contact point contacts the receiving surface is the force point. 3. 3. The clamp portion has a receiving surface which is in contact with the fastening member and pressed by the fastening member, and an intermediate member is provided between the receiving surface and the contact surface of the fastening member. Is disposed, and the intermediary member has an inclined surface that is inclined and comes into contact with the receiving surface or the contact surface, and the inclined surface and the receiving surface or the contact surface come into contact with each other. 2. The clamp mechanism for a throw-away tip according to claim 1, wherein the position is the force point.