JP2001062609A - 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 pressing part 31 provided on the tip of a clamp 22 is formed in a nearly mountain shape at a section view projected toward the upper surface upper 14a of a tip 13. A cross ridgeline 31A in parallel with a tip center line extending along the longitudinal direction of the tip 13 is formed by crossing a first pressing surface 31a for constituting the pressing part 31 with a second pressing part 31b. The cross ridgeline 31A out of the pressing part 31 is arranged so as to approach to the upper surface 14a of the tip 13 at the lowest position lowerside in Fig. and so as to orthgonally crossing with the tip axis P under such state that the bolt 26 is not tightened threadedly into a bolt mounted hole 28. The pressing part 31 is contacted with the upper surface 14a of the tip 13 at the cross ridgeline 31A under such state that the bolt 26 is tightened threadedly into the bolt mounted hole 28 so that the tip 13 is pressed and fixed by the cross ridgeline 31A.

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. 5 is a side view of the indexable cutting tool according to an example of the above-described prior art, FIG. 6 is a plan view of the indexable cutting tool shown in FIG. 5, and FIG. 7 is an indexable cutting tool shown in FIG. FIG. 8 is a sectional view of the tool taken along line AA, and FIG. 8 is a front view of the indexable cutting tool shown in FIG.

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 a hard material such as a cemented carbide, for example, 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. 6, the chip 13 is formed 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 formed at both ends in the longitudinal direction, which protrude toward the tip end of the tool body 11, can be 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 main body 11, and is provided so as to protrude from one end of the both ends at a position shifted from the axis O in the width direction at the front end of the tool body 11 toward the front end side. As shown in FIG. 6, the indexable cutting tool 10 is formed so as to be substantially L-shaped in plan view in the vicinity of the distal end portion thereof. That is, the pedestal portion 21 has a shorter length in the width direction (left-right direction in FIG. 8) than the tool body 11 in a cross-sectional view with respect to the axis O of the tool body 11 shown in FIG. The length (in the vertical direction in FIG. 8) orthogonal to the axis O and the width direction is shorter than the tool body 11.

Accordingly, as shown in FIG. 5, 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. Furthermore, as shown in FIG. 6, one of the two pedestal side surfaces 21B, 21B facing each other in the width direction of the tool main body 11 has two pedestal side surfaces 21B facing each other in the width direction of the tool main 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. 8, among the pedestal upper surface 21C and the pedestal lower surface 21D facing each other in a direction orthogonal to the axis O and the width direction of the tool main body 11, the pedestal lower surface 21D is smooth on the bottom surface 11D 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. 8, a chip mounting seat 23 is formed on the pedestal portion upper surface 21 </ b> C.
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. As shown in FIG. 5, a clearance 23c is formed on the base end side of the tip mounting seat 23.

As shown in FIG. 6, 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 which 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. 5) toward the distal end side from the indentation 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. 5) from the base side to the front end side, and the base 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. 5 and 7, 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.
5, and furthermore, as shown in FIG. 5, the side surface 14 c on the base 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. 6 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. 5 and 6, the fulcrum β in the clamp mechanism 12 is approximately located on the axis O near the base of the clamp portion 22, ie, 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. 6, the fulcrum β is located on the axis O of the tool main body 10a, 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 is not located on the plane T including the straight line L connecting the fulcrum β and the action point γ and parallel to the central axis Q of the bolt 26, and the screw portion 26c of the bolt 26 is inserted into the bolt mounting hole 28. 8, a torsional moment M around a straight line L as shown in FIG. 8 is generated, and the clamp portion 22 descends from the straight line L toward the power point α, and is orthogonal to the center axis Q of the bolt 26. Horizontal plane H
Is twisted at an inclination angle θ.

[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. 8) of the pressing portion 25 is the end on the center axis Q side of the bolt 27, and this end contacts 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 the chip axis P orthogonal to the chip center line R toward the chip side surface 14c, as shown in the 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
3 is flat, and the first contact portion ε1 at which the two contact with each other due to the torsional moment M of the clamp portion 22 is at a position greatly deviated from the chip axis P. And the third contact portions ε2 and ε3 are symmetrical with respect to the chip axis P,
And the third contact portions ε2 and ε3 exert a large imbalance in the resistance acting from the chip mounting seat 23, that is, the resistance against the force of the pressing portion 25 pressing the upper surface 14a of the chip 13 in the first contact portion ε1. 25, the clamping state of the chip 13 becomes unstable, for example, chatter vibration is likely to occur during the processing of the work, and the processing accuracy of the work is reduced. For example, the chip 13 falls off from the chip mounting seat 23 during the cutting processing. There is a risk of doing it. The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a clamp mechanism for a throw-away tip that can stably fix the throw-away tip by improving the clamp state of the throw-away 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 In a clamp mechanism of a throw-away tip, comprising a fastening member for displacing the pressing portion toward the tip mounting seat by fastening with a tool body, the pressing portion extends along a longitudinal direction of the throw-away tip. A projection protruding toward the center line, at which the pressing portion presses the throw-away tip. It is a symptom.

According to the clamp mechanism for a throw-away tip having the above-described structure, the pressing portion is provided with a projection projecting toward the center line along the longitudinal direction of the throw-away tip. When the clamp portion is displaced toward the tip mounting seat, when the clamp portion is displaced toward the tip mounting seat, for example, around a straight line connecting the fulcrum and the action point, such as when the force point of the clamp mechanism is not in a plane including the fulcrum and the action point. Even if the torsion moment acts and the pressing portion abuts on the throw-away tip in an inclined state, the protruding portion will abut on the vicinity of the center line along the longitudinal direction of the throw-away tip. It is prevented from abutting at a position far away from the vicinity of the center line of the throw-away tip, such as the end of the 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 tip mounting seat for mounting the throw-away tip is formed at the tip of the tool body of the cutting tool, and the tip is pressed against the throw-away tip. A base end side of a clamp having a pressing portion to be fixed at the distal end is connected to the tool body so as to be elastically deformable, and the pressing portion faces the chip mounting seat by fastening the clamp portion and the tool body. In the clamp mechanism of a throw-away tip including a fastening member that displaces the throw-away tip, the throw-away tip includes a tip protrusion that projects toward the pressing portion at a center line along a longitudinal direction of the throw-away tip. The pressing portion presses the throw-away tip through the tip protrusion. There.

According to the clamp mechanism for a throw-away tip having the above-described structure, a tip projecting portion is provided at the center line along the longitudinal direction of the throw-away tip so as to project toward the pressing portion. When the clamp portion is displaced toward the tip mounting seat because of contact with the portion, around the straight line connecting the fulcrum and the action point, for example, when the force point of the clamp mechanism is not in a plane including the fulcrum and the action point Even if the torsional moment acts on the pressing portion and the pressing portion abuts against the throw-away tip, the point of action is located near the center line along the longitudinal direction of the tip projecting portion, that is, the throw-away tip. There is no point of action at a position far away from the vicinity of the centerline of the throwaway tip, such as the end of the throwaway tip. And would it have been prevented.
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.

[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 front view of a throw-away type cutting tool according to an embodiment of the clamp mechanism for a throw-away tip of the present invention, as viewed from the tip. FIG. 2 is an enlarged front view of a main part of the throw-away type cutting tool shown in FIG. 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, the pressing portion 31 provided at the tip of the clamp portion 22 is formed in a substantially mountain shape in cross section projecting toward the upper surface 14 a of the chip 13, and has a first pressing surface 31.
a intersects the second pressing surface 31b, for example, the tip 13
Are formed at the intersection ridges (projections) 31A extending parallel to the chip center line R extending in the longitudinal direction of the chip. The crossing ridgeline portion 31A of the pressing portion 31 is the lowest (see FIG. 1).
And the upper surface 14 of the chip 13 at the position (lower side in FIG. 2).
The cross ridge 31A is arranged to be orthogonal to the chip axis P in a state where the bolt 26 is not screwed and tightened into the bolt mounting hole 28.
That is, when the bolt 26 is screwed and tightened into the bolt mounting hole 28, the pressing portion 31 and the upper surface 14 a of the chip 13 abut at the intersection ridge 31 A, and the intersection ridge 31 A
A becomes the first contact portion ε1.

Next, the operation of the clamp mechanism 12 when the tip 13 is mounted on the tool body 11 will be described. First, the bottom portion 14b of the chip 13 is attached to the chip mounting seat 23.
, And positioned between the tip mounting seat 23 and the pressing portion 31 of the clamp portion 22. The bolt 26 is inserted through 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. Then, the lower surface 26b of the bolt head and the receiving surface 27a of the bolt hole 27 come into surface contact with each other, and the receiving surface 27a is pressed by the lower surface 26b of the bolt head. The tip 13 is pressed toward the seat 23, and the tip 13 is pressed and fixed. At this time, the point of action γ in the clamp mechanism 12 is the first contact portion ε1 between the pressing portion 31 and the upper surface 14a of the chip 13.
The power point α of the clamp mechanism 12 approximately located on the center axis Q of the bolt 26 includes the straight line L connecting the fulcrum β located at the base of the clamp portion 22 and the action point γ. When the screw portion 26c of the bolt 26 is screwed and tightened in the bolt mounting hole 28 without being located in the plane T parallel to the axis Q, a torsional moment M around a straight line L as shown in FIG. Numeral 22 is inclined downward from the tip 13 toward the bolt 26, and a twist of an inclination angle θ is generated with respect to a horizontal plane H orthogonal to the central axis Q of the bolt 26.

Here, the pressing portion 31 is located on the upper surface 1 of the chip 13.
While being displaced in the direction approaching to 4a and tilting with respect to the chip 13 due to the torsional moment M,
Since the intersection ridgeline portion 31A of the first and second pressing surfaces 31a and 31b of the pressing portion 31 is located at the lowest position, the first contact portion ε1 at which the pressing portion 31 and the upper surface 14a of the chip 13 are in contact is Even at a position shifted from the center line R toward the center axis Q of the bolt 26, the position is near the chip center line R as shown in FIG. In this case, the clamp 2
The first contact portion ε1 at which the second pressing portion 25 contacts the upper surface 14a of the chip 13 is not located at a position greatly deviated from the chip center line R, and therefore, is disposed at a symmetrical position with the chip axis P interposed therebetween. The drag acting from the tip mounting seat 23 at the second and third contact portions ε2 and ε3,
At the contact portion ε1, the pressing portion 25 is
There is no large imbalance in the resistance to the pressing force of a, and the pressing portion 25 stably holds the tip 13 by clamping.

As described above, according to the clamp mechanism 10 of the indexable tip of the present embodiment, when the clamp portion 22 is displaced toward the tip mounting seat 23, the crossing ridge 31A of the pressing portion 25 is Since the chip 13 is in contact with the vicinity of the chip center line R along the longitudinal direction, the stability when the chip 13 is pressed and held by the pressing portion 31 and clamped can be improved. As a result, it is possible to prevent problems such as a reduction in the processing accuracy of the work, and a problem such as the chip 13 falling off from the chip mounting seat 23 during cutting.

In the present embodiment, the pressing portion 31 provided at the tip of the clamp portion 22 is formed in a substantially mountain shape in cross section projecting toward the upper surface 14a of the chip 13, and has a first pressing surface. 31a and the second pressing surface 31b intersect, for example, an intersection ridge line portion 31A parallel to the chip center line R
Is formed, but the present invention is not limited to this.
The pressing portion 41 is, for example, a flat pressing surface 41, as shown in a first modified example of a main part enlarged front view of the indexable cutting tool according to the present embodiment shown in FIG.
A and a projecting portion 42 having a substantially rectangular shape in cross section, for example, projecting from the pressing surface 41A toward the chip center line R of the upper surface 14a of the chip 13. Further, as shown in FIG. 3 (b), which shows a second modified example of a main part enlarged front view of the throw-away type cutting tool according to the present embodiment viewed from the tip, the pressing portion 51 has, for example, a flat surface shape. And a projecting portion 52 that projects from the pressing surface 51A toward the chip center line R of the upper surface 14a of the chip 13, for example, is substantially semicircular in cross section. In short, when the chip 13 is clamped and held, each of the pressing portions 41 and 51 and the upper surface 1 of the chip 13
4a may be in contact with the projections 42, 52.

Further, in the present embodiment, the pressing portion 31 provided at the tip of the clamp portion 22 is formed in a substantially mountain shape in cross section projecting toward the upper surface 14 a of the chip 13, and has a first pressing surface. 31a and the second pressing surface 31b intersect, for example, an intersection ridge line portion 31A parallel to the chip center line R
Is formed, but the present invention is not limited to this.
As shown in (a), a view showing a third modified example of a main part enlarged front view of the indexable cutting tool according to the present embodiment as viewed from the front end, a flat surface pressing portion 2 is provided at the front end of the clamp portion 22.
5 may be provided, and the upper surface 61 of the chip 13 may be formed to have a substantially mountain shape in cross section in which the first chip upper surface 61a and the second chip upper surface 61b intersect so as to protrude toward the pressing portion 25. . In this case, the first and second chip upper surfaces 61
The chip projection 61A formed by the intersection of the a and 61b only needs to intersect the chip axis P. Further, as shown in FIG. 4B, a fourth modification of the main part enlarged front view of the throw-away type cutting tool according to the present embodiment viewed from the front end is shown in FIG.
A chip protruding portion 72, for example, having a substantially rectangular shape in cross section, protruding from the flat upper surface 71 of the chip 13 toward the pressing portion 25.
Further, as shown in FIG. 4 (c), as shown in a fifth modified example of a main part enlarged front view of the throw-away type cutting tool according to the present embodiment as viewed from the front end, as shown in FIG. The portion 73 may be formed, for example, in a substantially semicircular cross section.

[0024]

As described above, according to the clamp mechanism of the throw-away tip of the first aspect of the present invention, the protrusion protrudes toward the center line along the longitudinal direction of the throw-away tip. Part is provided, and in order to abut the throw away tip at this protruding portion, the protruding portion comes into contact with the vicinity of the center line along the longitudinal direction of the throw away tip, and the pressing portion presses the throw away tip. Stability when holding the clamp can be improved.For example, chatter vibration is likely to occur when processing the work, and the processing accuracy of the work is reduced.For example, the indexable insert falls off the chip mounting seat during cutting. It is possible to prevent the occurrence of a problem such as the occurrence of a problem. Furthermore, according to the clamp mechanism of the throw-away tip of the present invention described in claim 2, a tip projecting portion that projects toward the pressing portion is provided at the center line along the longitudinal direction of the throw-away tip. Since the tip protruding portion is in contact with the pressing portion, the stability at the time of pressing and holding the throw-away tip by the pressing portion and clamping can be improved, and the throw-away tip of the present invention according to claim 1 described above. The same effect as the clamp mechanism can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a throw-away type cutting tool according to an embodiment of a clamp mechanism for a throw-away tip of the present invention, as viewed from the tip.

FIG. 2 is an enlarged front view of a main part of the indexable cutting tool shown in FIG.

FIG. 3A is a diagram showing a first modified example of a main part enlarged front view of the indexable cutting tool according to the embodiment shown in FIG. 1 as viewed from the tip, and FIG. It is a figure which shows the 2nd 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. 4A is a diagram showing a third modified example of the main part enlarged front view of the indexable cutting tool according to the present embodiment shown in FIG. 1 as viewed from the tip, and FIG. It is a figure which shows the 4th 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, and (c) is FIG.
It is a figure which shows the 5th modification of the principal part enlarged front view which looked at the throw-away type cutting tool which concerns on this embodiment shown in FIG.

FIG. 5 is a side view of a throw-away type cutting tool according to an example of the related art.

FIG. 6 is a plan view of the indexable cutting tool shown in FIG. 5;

FIG. 7 is a cross-sectional view of the indexable cutting tool shown in FIG.
FIG. 3 is a sectional view taken along line A.

FIG. 8 is a front view of the indexable cutting tool shown in FIG. 5 as viewed from the tip.

[Explanation of symbols]

 10, 30 Throw-away type cutting tool 11 Tool body 13 Throw-away tip (tip) 22 Clamp portion 23 Tip mounting seat 25, 31, 41, 51 Pressing portion 26 Bolt (fastening member) 31A Cross ridge portion 31A (projecting portion) 42 , 52 Projection 61A, 72, 73 Tip protrusion α Force point β Support point γ Action point M Torsional moment

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norio Aso 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. Mitsubishi Materials Corporation Tsukuba Works F-term (reference) 3C046 EE13 EE14 EE16

Claims (2)

[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. A clamp mechanism for a throw-away tip, comprising: a fastening member that displaces the pressing portion toward the tip mounting seat by fastening the clamp portion and the tool body. The pressing portion includes a protruding portion protruding toward a center line along a longitudinal direction of the throw away tip, wherein the pressing portion presses the throw away tip at the protruding portion. Tip clamping mechanism. 2. 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 formed on the tool body. A clamp mechanism for a throw-away tip, comprising: a fastening member that displaces the pressing portion toward the tip mounting seat by fastening the clamp portion and the tool body. The throw away tip includes a tip protrusion that projects toward the pressing portion at a center line along a longitudinal direction of the throw away tip, and the pressing portion places the throw away tip through the tip protrusion. A clamp mechanism for a throw-away tip characterized by pressing.