CN104582880A - Cutting insert, cutting tool and manufacturing method of cutting workpiece - Google Patents

Abstract

The cutting insert of one embodiment of the present invention is provided with an upper face, a lower face, a side face which is connected to both the upper face and the lower face, a through-hole which penetrates through the cutting insert from the upper face to the lower face, and a main cutting blade which is partially located at the line of intersection between the upper face and the side face and which has a circular arc shape in a plan view. In the plan view, the center of the through-hole is located so as to be offset further toward the side opposite the side where the circular arc-shaped main cutting blade is formed than the center of an imaginary circle, the outer periphery of which corresponds to the circular arc of the main cutting blade.

Description

Cutting insert, cutting tool and manufacturing method of cutting workpiece

technical field

The present invention relates to a cutting insert, a cutting tool and a manufacturing method of a cutting workpiece.

Background technique

As a cutting insert used for cutting a workpiece, there is known a throwaway insert described in Japanese Patent Application Laid-Open No. 7-15207 (Patent Document 1). Usually, such blades are screwed to the holder via a through hole formed in the center. The insert is used for cutting while being fixed to the tool holder. The insert described in Patent Document 1 has a circular outer periphery in plan view, and has a circular cutting edge, a chip breaker formed along the cutting edge, and a protrusion formed in the chip breaker. Cutting is performed by bringing a part of the circular cutting edge into contact with the workpiece.

In recent years, in order to perform fine cutting, small cutting inserts have been demanded. However, when simply downsizing the cutting insert, it is necessary to reduce the through hole or reduce the distance between the cutting edge and the through hole. When the through hole is excessively narrowed, it becomes difficult to stably fix the cutting insert to the holder. In addition, when reducing the distance between the cutting edge and the through hole, the chip breaker must be reduced. Therefore, it is difficult to make chips flow along the chip breaker groove.

Contents of the invention

A cutting insert according to one aspect of the present invention includes: an upper surface; a lower surface; side surfaces respectively connected to the upper surface and the lower surface; a through hole penetrating from the upper surface to the lower surface; The intersection between the upper surface and the side surface is partially provided, and is arc-shaped when viewed from above. In addition, when viewed from above, the center of the through hole is located on the main cutting edge formed with the arc shape toward the upper surface, compared with the center of an imaginary circle whose outer circumference corresponds to the arc of the main cutting edge. The position where one side of the blade is offset from the opposite side.

Description of drawings

Fig. 1 is a perspective view showing a cutting insert according to one embodiment of the present invention.

Fig. 2 is a plan view of the cutting insert shown in Fig. 1 .

Fig. 3 is a side view of the cutting insert shown in Fig. 1 .

Fig. 4 is a sectional view of the cutting insert shown in Fig. 2 along the A-A section.

Fig. 5 is a sectional view of the cutting insert shown in Fig. 2 along the B-B section.

Fig. 6 is a schematic diagram showing the outer periphery and through-holes of the cutting insert shown in Fig. 2 .

Fig. 7 is a schematic plan view of a first modified example of the cutting insert shown in Fig. 6 .

Fig. 8 is a schematic plan view of a second modified example of the cutting insert shown in Fig. 6 .

Fig. 9 is a schematic plan view of a third modified example of the cutting insert shown in Fig. 6 .

Fig. 10 is a perspective view showing a fourth modified example of the cutting insert shown in Fig. 1 .

Fig. 11 is a perspective view showing a cutting tool according to an embodiment of the present invention.

FIG. 12 is an enlarged perspective view of a region C of the cutting tool shown in FIG. 11 .

13 is a perspective view showing one step of the method of manufacturing a machined product according to the embodiment of the present invention.

14 is a perspective view showing one step of the method of manufacturing a machined product according to the embodiment of the present invention.

15 is a perspective view showing one step of the method of manufacturing a machined product according to the embodiment of the present invention.

Detailed ways

<Cutting Insert>

Hereinafter, a cutting insert 1 according to one embodiment will be described in detail using the drawings. However, in each of the drawings referred to below, for convenience of description, only main components necessary for describing the present invention among the components of the embodiment are shown in simplified form. Therefore, the cutting insert of the present invention may include arbitrary components not shown in the drawings referred to in this specification. In addition, the dimensions of the components in the drawings do not faithfully represent the dimensions of the actual components, the dimensional ratios of the components, and the like.

As shown in FIGS. 1 to 6 , the cutting insert 1 of this embodiment has an upper surface 3 , a lower surface 5 , and side surfaces 7 . The side surfaces 7 are respectively connected to the upper surface 3 and the lower surface 5 . The cutting insert 1 has a through hole 9 penetrating from the upper surface 3 to the lower surface 5 . In addition, the cutting insert 1 has an axis X perpendicular to the upper surface 3 and the lower surface 5 . The through hole 9 is parallel to the axis X and formed along the axis X. As shown in FIG.

The through hole 9 is provided for inserting a screw when the cutting insert 1 is screwed to the holder of the cutting tool. It should be noted that, as a method of fixing the cutting insert 1 to the holder, a method using a clamp structure may be employed instead of the method of screw fixing.

In the present embodiment, the penetration direction of the through hole 9 is defined as the vertical direction. In other words, let the extending direction of the axis X be the up-down direction. Furthermore, among the surfaces of the opening of the through-hole 9 , the surface on which the cutting edge is formed is referred to as the upper surface 3 , and the surface on which the cutting edge is not formed is referred to as the lower surface 5 . Therefore, the vertical direction of the cutting insert 1 of the present embodiment described in detail below does not necessarily coincide with the vertical direction when the cutting insert 1 is used.

In the cutting insert 1 of this embodiment, the maximum width of the upper surface 3 and the lower surface 5 is 5 to 20 mm. In addition, the height from the lower surface 5 to the upper surface 3 is 2 to 5 mm. Here, the height from the lower surface 5 to the upper surface 3 refers to the width in the direction parallel to the axis X between the upper end of the upper surface 3 and the lower end of the lower surface 5 .

An upper cutting edge is formed at the intersection of the upper surface 3 and the side surface 7 . The cutting insert 1 includes a major cutting edge 11 and a minor cutting edge 13 as an upper cutting edge. A major cutting edge 11 and a minor cutting edge 13 are partially provided at the intersection of the upper surface 3 and the side surface 7 . Specifically, the major cutting edge 11 is located on one end side (the left side in FIG. 2 ) of the upper surface 3 . In addition, the minor cutting edge 13 is located on the other end side (the right side in FIG. 2 ) of the upper surface 3 .

It should be noted that at this time, the intersection of the upper surface 3 and the side surface 7 is not a strict line shape formed by the intersection of the two surfaces. If the line of intersection between the upper surface 3 and the side surface 7 is sharply formed at an acute angle, the durability of the upper cutting edge will decrease. Therefore, a so-called honing process is performed on a portion where the upper surface 3 intersects with the side surface 7, and this portion becomes slightly curved.

In addition, the intersection portion has a pair of linear portions 15 in addition to the major cutting edge 11 and the minor cutting edge 13 . The minor cutting edge 13 and the major cutting edge 11 are continuous with a pair of linear portions 15 interposed therebetween. Specifically, the pair of linear portions 15 are continuous with both ends of the major cutting edge 11 . In addition, the pair of linear portions 15 are continuous with both ends of the minor cutting edge 13, respectively. In other words, one end portion of each of the pair of linear portions 15 is connected to the major cutting edge 11 . In addition, the other end portion of each of the pair of linear portions 15 is connected to the minor cutting edge 13 .

The major cutting edge 11 and the minor cutting edge 13 each have an arc shape in plan view. The center of the arc-shaped major cutting edge 11 is located at one end portion (the leftmost portion in FIG. 2 ) of the upper surface 3 . In addition, the center of the arc-shaped minor cutting edge 13 is located at the other end portion (the rightmost portion in FIG. 2 ) of the upper surface 3 . The radius of curvature of the arcuate major cutting edge 11 is larger than the radius of curvature of the arcuate minor cutting edge 13 . That is, the major cutting edge 11 draws a gentler curve than the minor cutting edge 13 .

The main cutting edge 11 in the cutting insert 1 of the present embodiment is a portion that functions as a main cutting edge in cutting, unlike a small curved cutting edge such as a so-called corner cutting edge. Therefore, the width L1 (width in the vertical direction in FIG. 2 ) of the major cutting edge 11 in the present embodiment is larger than the width L2 of the through hole 9 . In addition, the width between both ends of the major cutting edge 11 is also larger than the width L2 of the through hole 9 .

In addition, in this embodiment, the above-mentioned "width" means the distance in the direction orthogonal to the line segment which connects one end part of the upper surface 3, and the other end part. In addition, let the distance in the direction parallel to the line segment which connects the one end part of the upper surface 3, and the other end part be a "length."

The upper surface 3 and the lower surface 5 have substantially the same shape. That is, the outer periphery of the lower surface 5 is constituted by a relatively large arc, a relatively small arc, and a pair of linear portions continuous with these arcs. In this embodiment, the upper surface 3 and the lower surface 5 are similar in shape, but not the same size. The lower surface 5 is one size smaller than the upper surface 3 . As shown in FIG. 3 , the side surface 7 is formed so as to approach the axis X as it goes from the upper surface side to the lower surface side in a side view.

The side surface 7 is connected to the upper surface 3 and the lower surface 5 respectively, and functions as a flank. The side surface 7 has a curved region 7a and a planar region 7b. The curved region 7 a is connected to arc-shaped portions in the outer peripheries of the upper surface 3 and the lower surface 5 . The planar area 7 b is connected to a pair of linear portions 15 in the outer peripheries of the upper surface 3 and the lower surface 5 .

In the cutting insert 1 of the present embodiment, the intersection portion has a pair of straight line portions 15 respectively continuous with both ends of the main cutting edge 11 , and the side surface 7 has a planar region 7 b connected to the straight line portions 15 . With such a planar region 7b, the cutting insert 1 can be stably fixed to the holder.

When the cutting insert 1 is screwed to the holder with screws, the rotation of the cutting insert 1 around the central axis of the through hole 9 can be suppressed by bringing the planar region 7 b into contact with the holder. In addition, even when the cutting insert 1 is used, when a large force is applied to the cutting insert 1 in the direction of rotation, the cutting insert 1 and the holder are in surface contact in the region 7b, so the cutting can be stably suppressed. Insert 1 rotates.

In order to suppress the rotation of the cutting insert 1 more stably, it is preferable that the area of the planar region 7b in the side surface 7 is large. Therefore, it is preferable that the ratio occupied by the pair of linear portions 15 is high in the intersecting portion between the upper surface 3 and the side surface 7 . Specifically, it is preferable that the lengths of the pair of linear portions 15 are respectively longer than the inner diameter L2 of the through hole 9 .

In addition, to more stably suppress the rotation of the cutting insert 1 , it is preferable that the included angle θ between a pair of imaginary straight lines passing through the pair of straight line portions 15 in plan view is an acute angle. This is because, in such a case, the pair of linear portions 15 can be located away from the central axis of the through hole 9 .

In the cutting insert 1 of the present embodiment, as shown in FIG. 6 , the center 9a of the through hole 9 is located at It is a position offset from the side opposite to the side on which the arcuate major cutting edge 11 is formed in the upper surface 3 . In other words, when an imaginary circle R1 including the arc of the major cutting edge 11 is projected onto the upper surface 3, the center 9a of the through hole 9 is positioned closer to the upper surface 3 than the center R11 of the imaginary circle R1. The position of the other end of the surface 3. In FIG. 6 , the center 9 a of the through hole 9 is located on the right side of the center R11 of the virtual circle R1 .

Therefore, the distance between the major cutting edge 11 and the through hole 9 can be ensured to be large without excessively reducing the through hole 9 . In this embodiment, the side of the upper surface 3 on which the arc-shaped major cutting edge 11 is formed corresponds to one end side, and the side of the upper surface 3 farther from the arc-shaped major cutting edge 11 corresponds to the other end side. corresponding to the end side.

Specifically, it is preferable that the center 9a of the through hole 9 is located on the opposite side from the center R11 of the imaginary circle R1 at a distance of about 10 to 80% of the radius of the imaginary circle R1, that is, the radius of curvature of the major cutting edge 11. biased position. For example, when the radius of curvature of the major cutting edge 11 in the cutting insert 1 of the present embodiment is 3 mm, it is preferable that the center 9 a of the through hole 9 is located at the other end from the center R11 of the imaginary circle R1 The side of the head is offset by about 0.3-2.4mm. It should be noted that R2 indicates a virtual circle whose outer circumference corresponds to the arc of the minor cutting edge 13 in plan view.

In the cutting insert 1 of the present embodiment, the arc-shaped major cutting edge 11 is formed larger than a semicircle. In addition, the pair of linear portions 15 are smoothly continuous with the end portion of the arc-shaped major cutting edge 11 . Therefore, the width between the pair of straight portions 15 becomes narrower as it moves away from the main cutting edge 11 . Therefore, it is possible to suppress an excessive increase in the overall volume of the cutting insert 1 and ensure a large width of the main cutting edge 11 .

In the present embodiment, the distance between the pair of linear portions 15 becomes smaller as the distance between the pair of linear portions 15 increases from the main cutting edge 11 in plan view. In such a case, the distance between the portions of the side surface 7 connected to these linear portions 15 becomes smaller as going from one end portion side to the other end portion side.

Therefore, when the cutting insert 1 is fixed to the holder, the position of the cutting insert 1 can be easily determined. Specifically, when the cutting insert 1 is attached to the holder, positioning can be easily achieved by bringing the cutting insert 1 into contact with the holder in a direction from the major cutting edge 11 toward the minor cutting edge 13 in plan view.

In particular, in the present embodiment, the regions connected to the pair of linear portions 15 in the side surface 7 form a pair of planar regions 7b. Therefore, when the cutting insert 1 is fixed to the holder, the positioning of the cutting insert 1 can be performed more easily, and the cutting insert 1 can be more stably fixed to the holder.

At this time, the center 9 a of the through hole 9 is located closer to one end of the upper surface 3 than both ends of the major cutting edge 11 . Specifically, the center 9 a of the through hole 9 is located on one end side of the upper surface 3 than the line segment connecting both ends of the major cutting edge 11 . The closer the center 9 a of the through hole 9 is located to the other end, the greater the distance between the major cutting edge 11 and the through hole 9 can be increased.

In the present embodiment, the width between the pair of linear portions 15 becomes narrower as the distance from the main cutting edge 11 increases. Therefore, by forming the through-hole 9 at the above-mentioned position, it is possible to suppress an excessive decrease in the interval between the through-hole 9 and the pair of linear portions 15 . Thereby, the durability of the cutting insert 1 can be improved.

Cutting is performed by bringing one end side of the cutting insert 1 into contact with a workpiece in a state protruding from the holder of the cutting tool. Therefore, when performing fine cutting, the width of the cutting insert 1 is required to be small, but it is not necessarily required to reduce the length of the cutting insert 1 .

The upper surface 3 has a land surface 17 , a chip breaker 19 and a main surface 21 . The land surface 17 is located on the outer periphery of the upper surface 3 and is connected with the upper cutting edge. Specifically, land surfaces 17 are respectively provided on the inside of the major cutting edge 11 and the minor cutting edge 13 so as to be continuous with the major cutting edge 11 and the minor cutting edge 13 .

The chip breaker 19 is located closer to the center of the upper surface 3 than the land surface 17 is. The chip breaker groove 19 has a concave shape formed of surfaces including the first inclined surface 19a and the second inclined surface 19b. The height of the first inclined surface 19 a decreases toward the center of the upper surface 3 . The second inclined surface 19 b is located closer to the center than the first inclined surface 19 a, and increases in height toward the center of the upper surface 3 . The main surface 21 is located closer to the center than the chip breaker 19 . In addition, the main surface 21 is a flat surface perpendicular to the axis X. As shown in FIG.

The land surface 17 is formed as a flat surface substantially parallel to the lower surface 5 or as an inclined surface having a lower height toward the center of the upper surface 3 . It should be noted that "approximately parallel" does not mean strictly parallel, but means a slight inclination of about ±5°. When the lower surface 5 is not flat and it is difficult to evaluate whether it is parallel to the lower surface 5 , it is only necessary to compare with the axis X instead of the lower surface 5 . That is, it only needs to evaluate whether the land surface 17 is perpendicular to the axis X or not.

An upper cutting edge is formed at the intersection of the land surface 17 and the side surface 7 . The land surface 17 is provided to increase the strength of the upper cutting edge. When there is no land surface 17 , an upper cutting edge is formed at the intersection of the first inclined surface 19 a of the chip breaker 19 and the side surface 7 . As described above, the first inclined surface 19 a positioned inside the land surface 17 is an inclined surface whose height decreases toward the center of the upper surface 3 . Therefore, the inner angle formed by the first inclined surface 19a and the side surface 7 is relatively small. However, the interior angle formed by the land surface 17 and the side surface 7 is larger than the interior angle formed by the first inclined surface 19 a and the side surface 7 . Therefore, by having the land surface 17, the strength of the upper cutting edge can be improved.

It should be noted that if the purpose is to improve the machinability of the upper cutting edge, a configuration in which the upper cutting edge is formed at the intersection of the first inclined surface 19 a and the side surface 7 without the land surface 17 may also be employed. This is due to the sharp shape of the upper cutting edge. The width of the land surface 15 is represented by the distance between the outer circumference of the upper surface 3 and the upper end of the first inclined surface 19a. The width of the land surface 17 is appropriately set according to cutting conditions, and is set within a range of 0.05 to 0.2 mm, for example.

The chip breaker 19 is located inside the land surface 17 . In the cutting insert 1 of the present embodiment, chip breakers 19 are respectively formed inside the land surface 17 connected to the major cutting edge 11 and inside the land surface 17 connected to the minor cutting edge 13 . The chip breaker 19 functions as a so-called rake face that picks up cut chips in the upper cutting edge. Therefore, the chips of the workpiece flow in such a manner as to be conveyed on the surface of the chip breaker 19 . In order to pick up chips well, the first inclined surface 19 a of the chip breaker 19 is an inclined surface whose height becomes lower toward the center of the upper surface 3 .

The inclination angle represented by the angle formed by the lower surface 5 and the first inclined surface 19a in a cross section perpendicular to the first inclined surface 19a may be set within a range of, for example, 10° to 50°. The height of the first inclined surface 19a only needs to decrease toward the center of the upper surface 3 . Therefore, it may be composed of a plurality of regions having different inclination angles when viewed in cross-section, and may also have a concave curved shape.

The second inclined surface 19b is located inside the first inclined surface 19a. The second inclined surface 19b functions to spirally curl the chips flowing on the first inclined surface 19a. By deforming the chips into a helical shape, the cutting insert 1 can exhibit excellent chip discharge performance. Therefore, the height of the region close to the main surface 21 among the second inclined surfaces 19b increases as the distance from the outer periphery increases.

Specifically, the second inclined surface 19b is an inclined surface having a higher height on the central side than on the outer peripheral side of the upper surface 3 . The inclination angle represented by the angle formed by the lower surface 5 and the inclined surface of the second inclined surface 19b in a cross section perpendicular to the second inclined surface 19b is set, for example, within a range of 5° to 50°.

In the cutting insert 1 of the present embodiment, the arcuate major cutting edge 11 is partially provided at the intersection of the upper surface 3 and the side surface 7 . Moreover, the center 9a of the through-hole 9 is located in the position offset to the other end part side rather than the center R11 of the imaginary circle R1. Therefore, the chip breaker 19 has a structure in which the width of the portion adjacent to the arcuate center of the major cutting edge 11 is larger than the width of the portion adjacent to the arcuate end of the major cutting edge 11 .

Compared with the arc-shaped end portion of the major cutting edge 11 , the center of the arc of the major cutting edge 11 is used as the main cutting edge region during cutting. At this time, since the width of the area adjacent to the above-mentioned portion in the chip breaker 19 is relatively large, the workpiece can be stably flowed into the chip breaker 19 .

A plurality of protrusions are formed in the chip breaker groove 19 . In the cutting insert 1 of this embodiment, as shown in FIG. A second protrusion 25 is formed in the flute 19 . The first protrusion 23 and the second protrusion 25 are formed to deform the chips and stabilize the flow direction of the chips.

The plurality of first protrusions 23 respectively protrude from the central side where the main surface 21 is located toward the outer peripheral side where the land surface 17 is located. At this time, the plurality of first protrusions 23 in this embodiment do not protrude outward from the center R11 of the imaginary circle R1, but each follows an imaginary straight line Z extending from the center 9a of the through hole 9 toward the main cutting edge 11. protrude.

The chips flow so as to be conveyed on the land surface 17, the first inclined surface 19a, and the second inclined surface 19b, and are spirally curled on the second inclined surface 19b. That is, chips flow toward the second inclined surface 19b. In the present embodiment, since the second inclined surface 19b is formed at a constant distance from the through hole 9 , the chip flow direction is the direction from the major cutting edge 11 toward the through hole 9 .

The protrusions in this embodiment protrude along an imaginary straight line Z extending from the center 9 a of the through hole 9 toward the major cutting edge 11 , so the flow direction of chips can be stably controlled by the protrusions.

Examples of the material of the cutting insert 1 include cemented carbide, cermet, and the like. As the composition of cemented carbide, there are, for example, WC-Co, which is sintered by adding cobalt (Co) powder to tungsten carbide (WC), and WC-TiC-, which is formed by adding titanium carbide (TiC) to WC-Co. Co, or WC-TiC-TaC-Co made by adding tantalum carbide (TaC) to WC-TiC-Co. In addition, cermets are sintered composite materials in which metal is compounded with ceramic components, and specifically, titanium compounds containing titanium carbide (TiC) or titanium nitride (TiN) as main components are mentioned.

The surface of the cutting insert 1 can also be coated with a film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the film include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), aluminum oxide (Al ₂ O ₃ ), and the like.

The cutting insert 1 of the present embodiment has the upper surface 3 having the above-mentioned shape, but the outer peripheral shape of the upper surface 3 is not limited thereto. In the cutting insert 1 of the present embodiment, the intersection portion is composed of the main cutting edge 11, the minor cutting edge 13, and a pair of linear portions 15. The curved portion connects the main cutting edge 11 and a pair of straight portions 15 .

In addition, for example, it may be the shape of the modification shown in FIGS. 7-10. In order to clarify the difference from the modified example of FIGS. 7 to 10 , FIG. 6 shows a schematic diagram showing the outer shape and the position of the through-hole 9 when the cutting insert 1 shown in FIG. 2 is viewed from above.

As shown in FIG. 7, the first modified example is the same as the cutting insert 1 shown in FIG. 6. The intersection portion has a circular arc-shaped main cutting edge 11 and a pair of straight line portions 15, but the intersection portion does not have an arc shape. secondary cutting edge. In the case where the upper surface 3 has such a structure, it is possible to secure a large area in the planar shape of the side surface 7 . Therefore, the cutting insert 1 can be more stably fixed to the holder.

In addition, as shown in FIG. 8, the second modified example is the same as the cutting insert 1 shown in FIG. 15. On the other hand, in the second modified example, the radius of curvature of the major cutting edge 11 is equal to the radius of curvature of the minor cutting edge 13, and the pair of linear portions 15 are substantially parallel to each other. When the intersection portion has such a structure, the minor cutting edge 13 can be used in the same way as the major cutting edge 11 . For example, when the major cutting edge 11 is worn due to repeated cutting, the minor cutting edge 13 can be used in the same manner instead of the major cutting edge 11 .

It should be noted that the equal curvature radius is not limited to being strictly the same, but means that one radius of curvature is about 95% to 105% of the other radius of curvature. In addition, approximately parallel is not limited to being strictly parallel, and may have a deviation of about ±5°.

In addition, as shown in FIG. 9, the third modified example is the same as the cutting insert 1 shown in FIG. The end portion on the opposite side to the end portion connected to the main cutting edge 11 is connected by a straight line. When the intersection portion has such a structure, the length of the upper surface 3 can be shortened. In addition, since the region of the side surface 7 connected to the straight line connecting the pair of linear portions 15 has a planar shape, the cutting insert 1 can be more stably fixed to the holder by bringing this region into contact with the holder.

In addition, the cutting insert 1 shown in FIG. 1 has a structure in which a plurality of first protrusions 23 are formed in the chip breaker groove 19. However, as the protrusions, as shown in FIG. A third protrusion 27 structure.

<Cutting tool>

Next, a cutting tool 101 according to one embodiment of the present invention will be described using the drawings. It should be noted that FIG. 12 is an enlarged cross-sectional view of a portion where the cutting insert 1 is attached to the holder 103 in FIG. 11 .

As shown in FIGS. 11 and 12 , the cutting tool 101 according to the present embodiment includes: a tool holder 103 having an insert pocket 107 on the front end side; The cutting insert 1 represented by the above-mentioned embodiment.

The tool holder 103 is in the shape of an elongated rod. Furthermore, one insert pocket 107 is provided on the front end side of the tool holder 103 . The insert pocket 107 is a portion where the cutting insert 1 is mounted, and is open to the front end surface of the holder 103 . At this time, since the insert groove 107 is also open to the side surface of the holder 103, the cutting insert 1 can be easily attached. The insert pocket 107 has a seating surface parallel to the lower surface of the holder 103 and constraining side surfaces in a direction intersecting the seating surface.

The cutting insert 1 is installed in the insert pocket 107 . The cutting insert 1 is attached so that the cutting edge protrudes toward the front end side of the holder 103 . Specifically, the cutting insert 1 is attached to the holder 103 so that the arc-shaped main cutting edge 11 among the upper cutting edges protrudes outward from the front end of the holder 103 . The cutting insert 1 is attached to the insert pocket 107 so that the main cutting edge 11 of the above cutting edge is located at a position protruding most outward from the front end of the holder 103 .

In this embodiment, the cutting insert 1 is fixed to the holder 103 by screws 105 . That is, the screw 105 is inserted into the through hole 9 of the cutting insert 1, and the tip of the screw 105 is inserted into a threaded hole (not shown) formed in the insert pocket 107, so that the screw 105 is screwed into the threaded hole.

Steel, cast iron, etc. can be used for the tool holder 103 . In particular, it is preferable to use high toughness steel for these parts.

<Manufacturing method of machined product>

Next, a method of manufacturing a machined product according to an embodiment of the present invention will be described with reference to the drawings.

The cut workpiece is produced by cutting the workpiece 201 . The method of manufacturing a machined product in this embodiment includes the following steps. Right now,

(1) The process of rotating the workpiece 201;

(2) A step of bringing the main cutting edge 11 of the cutting tool 101 represented by the above-mentioned embodiment into contact with the rotating workpiece 201;

(3) A step of separating the cutting tool 101 from the workpiece 201 .

More specifically, first, as shown in FIG. 13 , the workpiece 201 is rotated in the Y1 direction around the axis Y. In addition, by moving the cutting tool 101 in the Y2 direction, the cutting tool 101 is brought relatively close to the workpiece 201 . Next, as shown in FIG. 14 , the main cutting edge 11 of the cutting tool 101 is brought into contact with the workpiece 201 to cut the workpiece 201 . And, as shown in FIG. 15 , by moving the cutting tool 101 in the Y3 direction, the cutting tool 101 is relatively separated from the workpiece 201 .

In the present embodiment, the cutting tool 101 is approached while the axis Y is fixed and the workpiece 201 is rotated. In addition, in FIG. 14 , the workpiece 201 is cut when the main cutting edge 11 of the cutting insert 1 comes into contact with the rotating workpiece 201 . In addition, in FIG. 15 , the workpiece 201 is separated from the cutting tool 101 while being rotated. It should be noted that, in the cutting process of the manufacturing method of the present embodiment, in each step, the cutting tool 101 is moved to bring the cutting tool 101 into contact with the workpiece 201 or to separate the cutting tool 101 from the workpiece 201 , of course it is not limited to this method.

For example, in the step (1), the workpiece 201 may be brought close to the cutting tool 101 . Similarly, in the step (3), the workpiece 201 may be separated from the cutting tool 101 . To continue cutting, it is only necessary to repeat the process of bringing the main cutting edge 11 of the cutting insert 1 into contact with different positions of the workpiece 201 while keeping the cutting tool 101 rotated.

In addition, as a representative example of the material of the workpiece 201, carbon steel, alloy steel, stainless steel, cast iron, or a non-ferrous metal etc. are mentioned.

Explanation of reference signs

1…cutting insert

3…upper surface

5…lower surface

7…side

9...Through hole

11...main cutting edge

13...Auxiliary cutting edge

15...a pair of straight sections

17...Margin surface

19... Chipbreaker

21...the main side

23…first protrusion

25…second protrusion

27…third protrusion

101…Cutting tools

103…knife holder

105…Screw

107...insert groove

201...Cutting piece

Claims (11)

1. a cutting insert, is characterized in that, possesses:

Upper surface;

Lower surface;

The side be connected respectively with described upper surface and described lower surface;

From the through through hole to described lower surface of described upper surface;

Arrange in the local, intersection portion of described upper surface and described side, and be the main cutting edge of arc-shaped when top view,

When top view, with periphery with imaginary circle corresponding to the circular arc of described main cutting edge center compared with, being centrally located to biased position, the opposition side being formed with the side of the main cutting edge of described arc-shaped of described upper surface of described through hole.

2. cutting insert according to claim 1, wherein,

Described intersection portion has and the two ends of described main cutting edge continuous print a pair straight line portion respectively.

3. cutting insert according to claim 2, wherein,

Described intersection portion also has front cutting edge, described a pair straight line portion is clipped between described front cutting edge and described main cutting edge, described front cutting edge is continuous with described main cutting edge by described a pair straight line portion, and described front cutting edge is arc-shaped when top view.

4. cutting insert according to claim 3, wherein,

The radius of curvature of described front cutting edge is less than the radius of curvature of described main cutting edge.

5. cutting insert according to any one of claim 1 to 4, wherein,

Described upper surface has the chip-breaker formed along described main cutting edge and the multiple projections be formed in this chip-breaker.

6. cutting insert according to claim 5, wherein,

Described multiple projection is arranged along the imaginary line extended from the center of described through hole towards described main cutting edge.

7. cutting insert according to claim 2, wherein,

When top view, along with leaving from described main cutting edge, interval each other diminishes described a pair straight line portion in described intersection portion.

8. cutting insert according to claim 7, wherein,

The part being positioned at the below of a pair straight line portion of described side is flat shape.

9. cutting insert according to claim 7, wherein,

The length of described a pair straight line portion is respectively than path length in described through hole.

10. a cutting element, possesses:

Knife rest, its front has edge cutter groove;

Cutting insert according to any one of claim 1 to 9, it is installed on described edge cutter groove with described main cutting edge from the mode that the front end of described knife rest is outstanding.

The manufacture method of 11. 1 kinds of machining things, comprising:

Make the operation being cut part rotation;

Make the described main cutting edge of cutting element according to claim 10 and the operation being cut part described in rotation and contacting;

Make described cutting element from the described operation being cut part and leaving.