JP2007301669A - Throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away tip capable of favorably handling wide-width and thin cutting chips in an undercut turning. <P>SOLUTION: This throw-away tip used for a profile turning is so formed that a chip breaker projection erecting upward from a rake face 21 includes a first breaker projection 30 extending along a bisector B of a corner cutting edge 22a, a second breaker projection 40 extending between the corner cutting edge 22a or a side cutting edge 22b and the first breaker projection 30; and the second breaker projection 40 is upward formed into a crest shape across the whole length of the extending direction on a cross section orthogonal to its extending direction and gradually rising to the rake face 21 on the cross section along the extending direction, is formed into the crest shape toward the corner cutting edge 22a or the side cutting edge 22b in the plan view, and makes the pointed part 41 of the crest shape approach to the corner cutting edge 22a or the side cutting edge 22b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a throw-away tip used for profile turning, and more particularly to a throw-away tip suitable for improving chip disposal in thinning turning.

  In the profile turning process of the inner diameter part of the part, in consideration of avoiding interference at the corner in the machining of the inner diameter part and avoiding interference when inserting and assembling other parts into the inner diameter part, In some cases, corner turning is performed. In this case turning, the throw-away insert is in contact with the work material over a wide area extending from the corner cutting edge formed in the nose and a pair of side cutting edges extending from the corner cutting edge. Chatter vibration was likely to occur because it received a higher load than peripheral turning, end face turning or profile turning. In hand turning, the feed amount was set to be relatively small to prevent chatter vibration. When the feed amount is small, the width and thickness of the chips are reduced, so that the chips are elongated and may get entangled with the bite body or damage the work surface.

  FIG. 7 shows a throw-away tip for the purpose of achieving reliable chip processing in a copying process in which the width and outflow direction of chips change sequentially. As shown in the figure, this throw-away tip has a rake face 2 formed on the polygonal surface of the polygonal flat plate main body 1, and a ridge portion of the polygonal face on which the rake face 2 is formed. A pair of cutting edges 4 and 4 extending from the corner portion C of the polygonal surface are formed. Further, the rake face 2 is inclined so as to be gradually depressed as the rake face 2 is separated from the cutting edge 4, and a land 7 is formed on the cutting edge 4 along the cutting edge 4. The angle of inclination of the rake face 2 and the land 7 is inclined from the tip of the corner portion C to the cutting edge 4 with the inclination angle smaller than the inclination angle of the surface 2 so as to be gradually depressed as the distance from the cutting edge 4 increases. The main dots 8 are formed in a convex spherical shape on the protruding end side of the corner portion C on the rake face 2 with a space between the cutting edge 4 and the rake face 2. And at least a pair of second dots 9 and 9 each having a convex spherical shape are formed at positions spaced apart from the main dot 8 along the pair of cutting edges 4 and 4, respectively (see FIG. For example, see Patent Document 1).

  The throw-away tip shown in FIG. 8 is provided with a corner cutting edge and a side cutting edge 7 connected to both ends of the corner cutting edge in the nose portion 5, and a breaker raised portion 10 on the rake face. The breaker ridge 10 is brought close to the tip of the nose 5 so that the distance d from the tip of the nose 5 to the rising boundary of the breaker ridge 10 is 0.03 mm to 0.20 mm, and its rake angle β is 10 ° to 22 °, and a portion having a rising angle γ of 43 ° to 52 ° in front of the breaker raised portion 10 facing the tip of the nose portion is provided (for example, see Patent Document 2).

  The throw-away tip shown in FIG. 9 has a planar polygonal shape, and a cutting edge 11 is formed on the outer edge of the upper surface. The first rake face 12 is inclined downward from the cutting edge 11, and the inclination is larger than the first rake face 12. The second rake face 13 is continuously formed, and a raised breaker 15 is provided on the upper surface in the vicinity of the nose part 14, and the first rake face 12 in the vicinity of the nose part 14 is provided. An auxiliary protrusion 16 having a mountain shape is formed toward the breaker 15, the inclination angle θ of the ridge line 16 a of the auxiliary protrusion 16, the inclination angle θ 1 of the first rake face 12, and the second rake face. The inclination angle θ2 of 13 satisfies the condition of θ1 <θ <θ2 (see, for example, Patent Document 3).

JP 2003-220503 A JP 2000-246516 A JP 2001-47306 A

  However, in the throw-away tip described in Patent Document 1, the wide and thin chips in the fillet turning process come into contact with only one point of the convex spherical surface of the main dot and the sub dot, so that the chip is restrained. There is a problem that chips are elongated for a long time because they cannot be curled or divided.

  In the throw-away tip described in Patent Document 2, the wide and thin chips in the fillet turning are preferentially curled only at the portion that comes into contact with the front surface of the breaker bulge portion 10, so that the other portion is the breaker bulge portion 10. There was a risk that the tool would not come into contact with the side surfaces of the tool and curled and split as a whole, and could become stretched and entangled with the tool.

  In the throw-away tip described in Patent Document 3, since the inclination angle θ of the ridge line 16a of the auxiliary protrusion 16 is larger than the inclination angle θ1 of the first rake face 12, the above-mentioned auxiliary protrusion is used in the thinning turning with a low feed amount. Since 16 does not contact the chips sufficiently and the chips cannot be guided toward the breaker 15, the chips may curl and divide sufficiently and may entangle with the tool.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a throw-away tip capable of satisfactorily treating a wide and thin chip in the fillet turning process.

  In order to solve the above problems, the present invention provides a rake face (21) formed on at least one polygonal surface of a chip body (10) having a polygonal flat plate shape, and a corner portion (12) of the polygonal surface. The corner cutting edge (22a) having an arcuate shape formed on the corner cutting edge (22a), the horizontal cutting edge (22b) formed on a pair of ridge sides extending from the corner cutting edge (22a), and the corner section (12) In the throw-away tip provided with the tip breaker projection rising upward from the internal rake face (21), the tip breaker projection is arranged along the bisector (B) of the corner cutting edge (22a). ) A first breaker protrusion (30) extending from the inside toward the corner cutting edge (22a), the corner cutting edge (22a) or the side cutting edge (22b), and the first breaker protrusion (30). Extending between The second breaker protrusion (40) includes a second breaker protrusion (40), and the second breaker protrusion (40) has a cross-sectional shape cut along a plane orthogonal to the extending direction, and is directed upward over the entire length in the extending direction. The breaker ridge line portion (44) that connects the tops of the mountain shape with respect to the rake face (21) as it forms a mountain shape and is separated from the cutting edge of the corner cutting blade (22a) in the extending direction. When gradually viewed from above, when viewed in plan, it forms a mountain shape toward the corner cutting edge (22a) or the side cutting edge (22b), and the peak portion (41) of the mountain shape is the corner cutting edge (22a) or The throw-away tip is characterized in that it is close to the horizontal cutting edge (22b) and a root portion (42) is formed close to or connected to the first breaker protrusion (30).

According to the present invention, the second breaker protrusion (40) deforms the thin and wide chips in the fillet turning process so as to follow the mountain shape of the cross-sectional shape, and the second breaker protrusion (40). Guide along the side and contact the side surface of the first breaker projection (30) to ensure curling. In the chips curled in this way, cracks are generated in the parts deformed into the above-mentioned mountain shape, and it becomes easy to divide by the cracks, so that it is suppressed that the chips are elongated and entangled with the tool, and good chip treatment is performed. Realize.
In addition, the second breaker protrusion (40) gradually rises upward with respect to the rake face (21) as it goes from the tip (41) to the root (42), so that the width of the second breaker protrusion (40) in the corner turning process is wide. The chips are surely guided to the first breaker protrusion (30) without causing the chips to curl abruptly, thereby enabling the above-described good chip treatment.

  In the above invention, the first breaker protrusion (30) is cut into a corner by taking into account that the chips guided to the second breaker protrusion (40) are surely brought into contact with the first breaker protrusion (30) to be curled and divided. It extends along the bisector (B) of the blade (22a) from the inside of the chip body (10) to a position closer to the corner cutting edge (22a) from the center of the arc of the corner cutting edge (22a). It is desirable.

  Further, in consideration of sufficiently drawing out the function of the second breaker protrusion (40), the second breaker protrusion (40) extends along the bisector (B) of the corner cutting edge (22a). At least one of the breaker protrusions (40a) or one or more breaker protrusions (40b, 40c) extending in the direction in which the angle (β) formed with the bisector (B) direction is in the range of 20 ° to 90 °. It is desirable to include one.

  Further, at least one second breaker protrusion (40) extending in a direction in which the angle (β) formed with the bisector (B) direction of the corner cutting edge (22a) is in the range of 20 ° to 90 °, One or more breakers extending in a parallel direction with reference to the second breaker protrusion (40) and arranged in parallel at a pitch interval of 0.05 mm or more and 1.0 mm or less on the side away from the corner cutting edge (22a) In the case of including the third breaker protrusion (50) made of the protrusions (50a, 50b), the action of curling the chips and generating cracks in the portion deformed into the mountain shape is further effective. Chip disposal becomes possible.

  Further, since a positive rake angle (α) is added to the rake face (21), the sharpness of the corner cutting edge (22a) and the side cutting edge (22b) is improved and the cutting resistance is reduced. The occurrence of chatter during the operation is suppressed. In addition, the chips are guided to the second breaker protrusion (40), and the action of the second breaker protrusion (40) can be pulled out more strongly.

  Further, the second breaker protrusion (40) and the third breaker protrusion (50) are cut from the rising start position (41a) of the tip (41) of the corner cutting edge (22a) or the side cutting edge (22b). And the rising angle (δ2, δ3) from the rake face (21) in the extending direction is greater than 0 ° and not more than 30 °. It is preferable that it is in the range in terms of chip disposal. When the distance (L) is less than 0.01 mm, the chips are strongly rubbed against the tip (41) of the second breaker projection (40), which may increase the cutting resistance, and when the distance exceeds 0.20 mm. There exists a possibility that a chip | tip may extend without contacting a 2nd breaker protrusion (40). On the other hand, when the rising angle (δ2, δ3) is 0 ° or less, the function of guiding the chips to the first breaker protrusion (30) becomes weak, and when the rising angle (δ2, δ3) exceeds 30 °, the chips Is strongly rubbed against the second breaker protrusion (40), resulting in an increase in cutting resistance or curling in the second breaker protrusion (40) and may not contact the first breaker protrusion (30).

  Furthermore, the rising angle (γ1, γ2, γ3) of the side surface (43a, 53a) of the first breaker protrusion (30), the second breaker protrusion (40) and the third breaker protrusion (50) with respect to the rake face (21) is 10 It is preferably in the range of not less than 60 ° and not more than 60 °. This is because in the first breaker protrusion (30), when the rising angle (γ1) is less than 10 °, the function of curling the chips becomes weak, and when it exceeds 60 °, clogging of the chips may occur. In the second breaker protrusion (40) and the third breaker protrusion (50), when the rising angle (γ2, γ3) is less than 10 °, the tops of the mountain-shaped cross sections of these breaker protrusions (40, 50) are sharp. This is because the chip cannot be deformed and the chip cannot be deformed, and if it exceeds 60 °, the top is too sharp and may be lost due to contact with the chip.

  Hereinafter, a first embodiment of a throw-away tip according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a corner portion of a throw-away tip according to a first embodiment to which the present invention is applied. FIG. 2 is an end view taken along line S1-S1 in FIG. FIG. 3 is an end view taken along line S2-S2 in FIG. FIG. 4 is an end view taken along line S3-S3 in FIG. The chip body 10 of the present throwaway chip 1 has a substantially rhombic flat plate shape, a rake face 21 is formed on at least one of the opposing rhomboid faces 11, and a pair of acute corner portions 12 on the diagonal of the rhombus face 11. As shown in FIG. 1, a corner cutting edge 22a having an arc shape and a pair of horizontal cutting edges 22b extending linearly from the corner cutting edge 22a are formed on the peripheral edge of each. The rake face 21 is a rake face 21 with a positive rake angle α that gradually becomes lower as the distance from the corner cutting edge 22a and the side cutting edge 22b increases. Corner flank surfaces 23a and side flank surfaces 23b are formed on the side surfaces 13 extending from the corner cutting blades 22a and the side cutting blades 22b, respectively. The corner flank 23 a and the side flank 23 b are flank surfaces having a flank angle of 0 ° intersecting the rhombus surface 11 at a right angle. The chip body 10 is made of a hard material such as cemented carbide or cermet, and a boss surface 24 made of a flat surface higher than the corner cutting edge 22a and the side cutting edge 22b is formed at the center of the rhombus surface 11 thereof. In addition, a mounting hole 25 is provided in the central portion of the rhombus surface 11 (not shown) that penetrates in the thickness direction of the chip body 10. The boss surface 24 functions as a seating surface when the throwaway tip is attached to a shank of a bite (not shown), and the mounting hole 25 is associated with fixing means such as a clamp lever, a clamp pin, and a mounting bolt. To match.

  The rake face 21 of the corner portion 12 rises above the rake face 21 and extends from the inside of the chip body 10 toward the corner cutting edge 22a along the bisector B of the corner cutting edge 22a. A first breaker protrusion 30 is formed. The first breaker protrusion 30 has a base portion 31 continuously connected to the boss surface 24 located inside the chip body 10 and has a substantially trapezoidal cross-sectional shape cut along a plane orthogonal to the extending direction. It is formed in a substantially triangular shape.

  Furthermore, a second breaker protrusion 40 extending along the bisector B is formed on the rake face 21 of the corner portion 12 between the corner cutting edge 22a and the first breaker protrusion 30. The second breaker projection 40 has a cross-sectional shape cut along a plane orthogonal to the extending direction, and forms a mountain shape upward over the entire length of the extending direction, and the corner cutting in the extending direction is performed. As the distance from the cutting edge of the blade 22a increases, the breaker ridge line portion 44 connecting the tops of the above-mentioned mountain shapes gradually rises with respect to the rake face 21, and when viewed in plan, forms a mountain shape toward the corner cutting edge 22a. A mountain-shaped point 41 is close to the corner cutting edge 22 a, and a root 42 is formed so as to be connected to the first breaker protrusion 30.

According to the throw-away tip 1 having the above-described configuration, the second breaker protrusion 40 deforms the thin and wide chip in the fillet turning so as to follow the mountain shape of the cross-sectional shape, and the second breaker projection 40 It guides along the protrusion 40 and contacts the side surface of the first breaker protrusion 30 to be surely curled. In the chips curled in this way, cracks are generated in the parts deformed into the above-mentioned mountain shape, and it becomes easy to divide by the cracks, so that it is suppressed that the chips are elongated and entangled with the tool, and good chip treatment is performed. Realize.
Further, since the second breaker protrusion 40 rises gently upward with respect to the rake face 21 as it goes from the tip part 41 to the root part 42, it does not abruptly curl wide chips in the fillet turning process. It is surely guided to the first breaker protrusion 30 to enable the above-described good chip disposal.

As shown in FIG. 1, if the tip 31 of the first breaker protrusion 30 is located slightly closer to the corner cutting edge 22a than the center of curvature of the corner cutting edge 22a, the first breaker protrusion 30 is guided to the second breaker protrusion 40. Since the chips reliably come into contact with the first breaker protrusions 30 and are curled and divided, an effective chip treatment can be performed.
Further, as shown in FIG. 2, the side surface 33 of the first breaker protrusion 30 is inclined upward with respect to the horizontal plane H in a cross section cut along a plane perpendicular to the corner cutting edge 22a and the horizontal cutting edge 22b. The rising angle γ1 is set in the range of 10 ° to 60 °. This is because when the rising angle γ1 is less than 10 °, the function of curling the chips becomes weak, and when it exceeds 60 °, clogging of chips may occur.

In the plan view shape illustrated in FIG. 1, the second breaker protrusion 40 has a distance L from the rising start position 41a at which the tip 41 starts rising from the rake face 21 to the cutting edge of the corner cutting edge 22a is 0.01 mm or more. It is formed so as to be within a range of 20 mm or less. This is because when the distance L is less than 0.01 mm, the chips are strongly rubbed against the tip 41 of the second breaker projection 40, and thus there is a risk of increasing cutting resistance. When the distance exceeds 0.20 mm, the chips are This is because there is a possibility that the two breaker protrusions 40 may extend without contacting.
Further, the root portion 42 of the second breaker protrusion 40 is connected to the side surface 33 of the first breaker protrusion 30 facing the corner cutting edge 22a. This is because the chips induced by the second breaker protrusion 40 are brought into contact with the side surface of the first breaker protrusion 30 to be curled and divided. Here, considering that the side surface 33 of the first breaker protrusion 30 is surely in contact with the chips, the side surface 33 is equidistant or higher than the highest point of the breaker ridge line portion 44 of the second breaker protrusion 40. It is desirable to be formed.

Further, as shown in FIG. 3, the side surface 43 of the second breaker protrusion 40 has a pair of side surfaces 43 rising upward from the rake face 21 in a cross section cut by a plane orthogonal to the extending direction. The rising angle γ2 with respect to the horizontal plane H is preferably in the range of 10 ° to 60 °. This is because when the rising angle γ2 is less than 10 °, the tops of the mountain-shaped cross sections of the breaker projections 40 are not sharp and the chips cannot be deformed, and when it exceeds 60 °, the tops are too sharp. This is because there is a risk of loss due to contact with chips. In the present embodiment, the top portion is rounded by an arc having an appropriate radius of curvature, but may not be rounded at all.
Furthermore, as shown in FIG. 4, in the cross section cut by a plane parallel to the extending direction, the breaker ridge line portion 44 gradually increases with respect to the rake face 21 as the distance from the cutting edge of the corner cutting edge 22 a increases. It is desirable that the rising angle δ2 be in the range of more than 0 ° and 30 ° or less. This is because, when the rising angle δ2 becomes 0 ° or less, the function of guiding the chips to the first breaker protrusion 30 becomes weak, and when the rising angle δ2 exceeds 30 °, the chips strongly rub against the second breaker protrusion 40. This is because the cutting resistance is increased, or there is a possibility that the cutting breaker 40 curls in the second breaker protrusion 40 and does not come into contact with the first breaker protrusion 30.

  Furthermore, since the rake face 21 connected to the corner cutting edge 22a and the side cutting edge 22b is formed of an inclined surface with a positive rake angle α, the corner cutting edge 22a and the side cutting edge 22b have excellent sharpness and low cutting resistance. For this reason, the occurrence of chatter when the turning turning process is performed is suppressed. Moreover, the chips are guided to the second breaker protrusion 40, and the function of the second breaker protrusion 40 is further enhanced.

  Next, a throw-away tip according to a second embodiment to which the present invention is applied will be described with reference to the drawings. 5 and 6 are plan views of the throw-away tip according to the second embodiment. 5 and 6, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 5, the second breaker protrusion 40 is the same as the breaker protrusion 40 a extending along the bisector B direction of the corner cutting edge 22 a (the same as the second breaker protrusion 40 of the first embodiment). ) And the bisector B direction is a direction in which the angle β is about 45 °, and the breaker protrusion 40b extends on the normal line of the corner cutting edge 22a. In the modification shown in FIG. 6, the second breaker protrusion 40 is symmetrical with respect to the bisector B and has an angle β of about 45 ° with the bisector B direction. And a pair of breaker protrusions 40b and 40c respectively extending on the normal line of the corner cutting edge 22a. The breaker protrusions 40a, 40b, and 40c constituting the second breaker protrusion 40 have a cross-sectional shape cut along a plane perpendicular to the extending direction and a cross-sectional shape cut along a plane parallel to the extending direction. The shape is the same as that described in the first embodiment.

According to the throw-away tip 1 having the above configuration, the second breaker protrusion 40 has three breaker protrusions 40a extending in directions in which the angles β formed with the bisector B direction of the corner cutting edge 22a are different from each other. , 40b, 40c, so that wide and thin chips in the fillet turning are guided to the first breaker projection 30 and curled, and a crack is formed in the portion deformed into a mountain shape by contact with the second breaker projection 40. Since the action to generate is increased, more effective chip disposal becomes possible.
Breaker projections 40b other than the breaker projections 40a extending along the bisector B, taking into account that the second breaker projections 40 can sufficiently obtain a function of guiding chips to the first breaker projections 30. The direction in which 40c extends is preferably such that the angle β formed with the bisector B direction is in the range of 20 ° to 90 °. This is because if the angle β is less than 20 °, the action of guiding the chips to the first breaker protrusion 30 is not strengthened, and if it exceeds 90 °, the flow of chips may be changed and hindered.

Next, a third embodiment of the throw-away tip according to the present invention will be described with reference to the drawings. FIG. 7 is a plan view of the throw-away tip according to the third embodiment. In FIG. 7, the same components as those in the first embodiment and the second embodiment are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 7, the breaker extending along the bisector B of the corner cutting edge 22a is formed on the rake face 21 of the corner portion 12 between the first breaker projection 30 and the corner cutting edge 22a. A second breaker comprising a pair of breaker protrusions 40b and 40c that are symmetrical with respect to the bisector B and extend in a direction of 45 ° at an angle β formed between the bisector B and the bisector B direction. A protrusion 40 is formed. The pointed portion 41 of each breaker projection 40a, 40b, 40c constituting the second breaker projection 40 is close to the corner cutting edge 22a, and the root portion 42 is connected to the side surface 33 of the first breaker projection 30.
Furthermore, the pitch interval extends in the direction parallel to the pair of breaker protrusions 40b and 40c (the angle β with the bisector B direction is 45 °) and away from the corner cutting edge 22a. A third breaker protrusion 50 comprising a pair of breaker protrusions 50a, 50b arranged in parallel in a range of 0.05 mm or more and 1.0 mm or less is formed, and each pointed portion 51 of the pair of breaker protrusions 50a, 50b is a horizontal cutting edge. Each base portion 52 is connected to the side surface 33 of the first breaker protrusion 30 while being close to 22b.

The breaker protrusions 40a to 40c, 50a, 50b constituting the second breaker protrusion 40 and the third breaker protrusion 50 are the same as those in the first embodiment shown in FIG. 3 when viewed in a cross section orthogonal to the extending direction. As in the case of the second breaker protrusion 40, the first embodiment shown in FIG. 4 is formed when viewed from a cross section parallel to each extending direction, with the top of the inverted V-shaped mountain being rounded upward. As with the second breaker protrusion 40 in FIG. 4, the breaker ridges 44 and 54 are formed so as to be gradually higher with respect to the rake face 21 as they are separated from the cutting edge of the corner cutting edge 22a. Alternatively, an inverted V-shaped mountain shape is formed toward the horizontal cutting edge 22b, and the corner cutting is performed from the rising start position 51a at which the peak portions 41 and 51 of the mountain shape start rising from the rake face 21. 22a or side cutting distance L to the cutting edge of the blade 22b is formed to be in close positions in the range of 0.01mm or 0.20mm or less.
Furthermore, each breaker protrusion 40a-40c, 50a, 50b is set in the range whose rising angles (gamma) 2 and (gamma) 3 of those side surfaces 43 and 53 are 10 degrees or more and 60 degrees or less, and follows breaker ridgeline parts 44 and 54. The direction rising angles δ2 and δ3 are set in the range of 0 ° to 30 °.

  According to the third embodiment having the above configuration, the effect of the second embodiment described above is further enhanced by the addition of the third breaker protrusion 50. Furthermore, the number of breaker protrusions 50a and 50b constituting the third breaker protrusion 50 can be increased as appropriate along the direction of the side cutting edge 22b. In the case where chips are generated from a wide range of the horizontal cutting edge 22b at the time of turning, effective chip treatment can be performed.

It is a top view of the corner part of 1st Embodiment which concerns on this invention. It is the S1-S1 line end view in FIG. FIG. 2 is an end view taken along line S2-S2 in FIG. It is the S3-S3 line end view in FIG. It is a top view of the corner part of 2nd Embodiment which concerns on this invention. It is a top view which shows the modification of 2nd Embodiment. It is a top view of the corner part of 3rd Embodiment which concerns on this invention. It is a top view of the conventional throw away tip. It is a principal part perspective view of another conventional throwaway tip. It is a figure explaining the other conventional throwaway tip, (a) is a principal part top view, (b) is a principal part perspective view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throw away tip 10 Tip body 12 Corner part 21 Rake face 22a Corner cutting edge 22b Side cutting edge 23a Corner relief face 23b Lateral relief face 30 First breaker protrusion 40 Second breaker protrusion 43 Side surface of second breaker protrusion 50 Third breaker Protrusion 53 Side surface L of third breaker protrusion Distance from start point of rising edge of second and third breaker protrusions to blade edge α Rake angle β Bisecting direction of corner cutting edge and extending direction of second breaker protrusion Side angle γ1 formed by the first breaker protrusion side face rising angle γ2 Second breaker protrusion side face rising angle γ3 Third breaker protrusion side face rising angle δ1 First breaker protrusion side edge rising angle δ2 Second Rise angle δ3 of the breaker ridge line of the breaker protrusion Rise of the breaker ridge line of the third breaker protrusion Angle

Claims (8)

A rake face (21) formed on at least one polygonal surface of a chip body (10) having a polygonal flat plate shape, and an arcuate corner cutting edge formed on a corner portion (12) of the polygonal surface. (22a), a horizontal cutting edge (22b) formed on a pair of ridges extending from the corner cutting edge (22a), and a chip rising upward from the rake face (21) in the corner (12) In throw-away tip with breaker protrusion,
The chip breaker protrusion is a first breaker protrusion extending from the inside of the chip body (10) toward the corner cutting edge (22a) along a bisector (B) of the corner cutting edge (22a). 30) and a second breaker protrusion (40) extending between the corner cutting edge (22a) or the side cutting edge (22b) and the first breaker protrusion (30),
The second breaker protrusion (40) has a cross-sectional shape cut along a plane orthogonal to the extending direction, and forms a mountain shape upward over the entire length of the extending direction, and in the extending direction. The breaker ridge line portion (44) connecting the tops of the mountain-shaped portions gradually increases with respect to the rake face (21) as it is separated from the cutting edge of the corner cutting edge (22a) or the side cutting edge (22b),
When viewed in a plan view, it forms a mountain shape toward the corner cutting edge (22a) or the side cutting edge (22b), and the peak portion (41) of the mountain shape is the corner cutting edge (22a) or the side cutting edge. The throw-away tip is characterized in that it is close to (22b) and the base (42) is formed close to or connected to the first breaker projection (30). The first breaker protrusion (30) extends along the bisector (B) of the corner cutting edge (22a) from the inside of the chip body (10) to the corner cutting edge from the center of the arc of the corner cutting edge (22a). (22a) The throw-away tip according to claim 1, wherein the throw-away tip extends to a position closer to it. The throw according to claim 1 or 2, wherein the second breaker protrusion (40) includes a breaker protrusion (40a) extending along a bisector (B) of the corner cutting edge (22a). Away tip. One or more breakers extending in a direction in which an angle (β) between the second breaker protrusion (40) and a bisector (B) direction of the corner cutting edge (22a) is in a range of 20 ° to 90 ° The throw-away tip according to any one of claims 1 to 3, further comprising a protrusion (40b, 40c). At least one second breaker projection (40) extending in a direction in which the angle (β) formed with the bisector (B) direction of the corner cutting edge (22a) is in the range of 20 ° to 90 °, One or more breaker protrusions extending in a parallel direction with respect to the second breaker protrusion (40) and arranged in parallel at a pitch interval of 0.05 mm or more and 1.0 mm or less on the side away from the corner cutting edge (22a) The throwaway tip according to any one of claims 1 to 4, further comprising a third breaker projection (50) made of (50a, 50b). The throw-away tip according to any one of claims 1 to 5, wherein the rake face (21) is an inclined face with a positive rake angle (α). The second breaker protrusion (40) and the third breaker protrusion (50) are cut from the rising start position (41a) of the tip (41) of the corner cutting edge (22a) or the side cutting edge (22b). And the rising angle (δ1, δ2) with respect to the rake face (21) in the extending direction is in the range of greater than 0 ° and less than or equal to 30 °. The throw-away tip according to claim 1, wherein the throw-away tip is formed as described above. Rising angles (γ1, γ2, γ3) of the side surfaces (33a, 43a, 53a) of the first breaker protrusion (30), the second breaker protrusion (40) and the third breaker protrusion (50) with respect to the rake face (21) The throw-away tip according to any one of claims 1 to 7, wherein is in a range of more than 10 ° and not more than 60 °.

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