JP7036797B2 - Manufacturing method for drills and machined products - Google Patents

Description

This aspect relates to a method for manufacturing an insert, a drill, and a machined product used for drilling and the like.

As an example of a drill used for drilling a work material such as metal, a drill with a replaceable cutting edge described in Japanese Patent Application Laid-Open No. 2007-203454 (Patent Document 1) is known. The drill described in Patent Document 1 includes a drill body and two cutting inserts. One of the two inserts is located near the axis of rotation of the drill body and is used for cutting on the inner circumference side, and the other of the two inserts is located away from the axis of rotation of the drill body and is used for cutting on the outer peripheral side. Used for.

It is necessary to pay attention to the chip discharge property in the cutting on the inner peripheral side in the drilling process as compared with the general milling process. In the drill described in Patent Document 1, the opening of the through hole into which the screw for fixing the cutting insert to the holder is inserted has a convex shape. Since the opening has a convex shape as described above, the possibility that the chips come into contact with the screw is reduced, and the dischargeability of the chips is improved.

However, there are increasing demands for miniaturization and high efficiency of drills, and the drill described in Patent Document 1 is insufficient to meet these demands. This is because in order to meet the demands for miniaturization and high efficiency, it is necessary to secure an area of the rake face located along the cutting edge, and it is not possible to secure a space for making the opening convex. Responsible.

Therefore, there has been a demand for a cutting insert capable of improving the chip discharge property while securing the area of the rake face.

The drill based on one embodiment has a rod shape extending from the first end to the second end along the axis of rotation, and has an inner blade pocket and an outer blade pocket located on the side of the first end, respectively. It includes a holder, an inner blade insert attached to the inner blade pocket, and an outer blade insert attached to the outer blade pocket. The inner blade insert includes a first side, an upper surface having a first angle and a second angle adjacent to the first side, and a through hole opened in the upper surface. The first angle is located closer to the axis of rotation than the second angle. The first side includes a first part located in the center of the length of the first side, a second part located between the first part and the first corner, the first part and the second part. It has a third site located between the corners. The upper surface is located along the first portion and is inclined downward as the distance from the first portion is increased, and the upper surface is located along the second portion and away from the second portion. Therefore, it has a second region inclined downward and a third region located along the third portion and inclined downward as the distance from the third portion increases. Further, the upper surface is located between the second region and the opening portion of the through hole, and is located between the fourth region having a smaller inclination angle than the second region and the third region and the opening portion. Further, it has a fifth region having a smaller inclination angle than the third region. Further, the first region and the opening portion are connected. The second region has a second outer region and a second inner region located between the second outer region and the fourth region and having a larger inclination angle than the second outer region. There is. The third region has a third outer region and a third inner region located between the third outer region and the fifth region and having a larger inclination angle than the third outer region. There is. Then, in the cross section orthogonal to the third portion, the extension line of the surface of the third outer region intersects with the fifth region.

It is a perspective view which shows the cutting insert of an embodiment. It is a top view of the cutting insert shown in FIG. 1. It is a side view which looked at the cutting insert shown in FIG. 2 from the A1 direction. It is an enlarged view in the area A2 shown in FIG. It is sectional drawing of the B1-B1 cross section in the cutting insert shown in FIG. It is sectional drawing of the B2-B2 cross section in the cutting insert shown in FIG. It is sectional drawing of the B3-B3 cross section in the cutting insert shown in FIG. It is a perspective view which shows the cutting tool of an embodiment. It is a side view of the cutting tool shown in FIG. 8 as seen from the A3 direction. It is a side view which looked at the cutting tool shown in FIG. 8 from the A4 direction. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment.

Hereinafter, the cutting insert 1 of the embodiment will be described in detail with reference to the drawings. However, each figure referred to below is shown in a simplified manner only for the main members necessary for explaining the present embodiment for convenience of explanation. Accordingly, the insert may comprise any component not shown in each of the figures referenced herein. Further, the dimensions of the members in each drawing do not faithfully represent the dimensions of the actual constituent members and the dimensional ratio of each member.

<Insert>
The cutting insert 1 (hereinafter, also simply referred to as insert 1) is suitably used as an insert on the inner peripheral side in a drill with a replaceable cutting edge. For example, the insert 1 of the example shown in FIG. 1 includes an upper surface 3, a lower surface 5, a side surface 7, a cutting edge 9, and a through hole 11.

As shown in FIG. 2, the upper surface 3 is a polygonal shape having a plurality of corners and sides. The upper surface 3 in the example shown in FIG. 2 has a substantially quadrangular shape and has four corners and four sides. The four corners and the four sides are positioned so as to be rotationally symmetric at 90 ° with respect to the central axis X1 in the front view (top view) of the upper surface 3.

The polygonal shape does not mean that the shape is strictly a polygon. For example, the four angles of the upper surface 3 in the example shown in FIG. 2 are not exact angles. The four corners may each have a rounded shape in top view, in other words, an outwardly convex curved shape. Further, each of the four sides does not have to have a strict linear shape. For example, in the example shown in FIG. 2, each of the four sides is slightly convex toward the outside.

One of the four sides is the first side 3a, and the two corners adjacent to the first side 3a are the first corner 3b (the corner located at the lower left in FIG. 2) and the second corner 3c (the right in FIG. 2). The corner located below). When the insert 1 is used as an insert on the inner peripheral side of the drill, the insert 1 is attached to the holder so that the first corner 3b is located closer to the rotation axis of the drill than the second corner 3c.

The first side 3a of the example shown in FIG. 2 has a first part 3aa, a second part 3ab, and a third part 3ac. The first portion 3aa is located so as to include the center of the first side 3a. In other words, the first portion 3aa is located at the center of the length of the first side 3a. The second site 3ab is located between the first site 3aa and the first corner 3b. The third site 3ac is located between the first site 3aa and the second angle 3c. That is, in the example shown in FIG. 2, the second portion 3ab, the first portion 3aa, and the third portion are directed from the end on the side of the first corner 3b on the first side 3a toward the end on the side of the second corner 3c. 3acs are lined up in order.

As shown in FIG. 3, the lower surface 5 is a surface located on the opposite side to the upper surface 3, and may function as a seating surface for the pocket when the insert 1 is attached to the holder. The lower surface 5 may have a polygonal shape like the upper surface 3. At this time, the lower surface 5 may have a shape that is one size smaller than the upper surface 3. In the example shown in FIG. 3, since the lower surface 5 has a shape one size smaller than the upper surface 3, the outer peripheral edge of the lower surface 5 is obscured by the upper surface 3.

The shapes of the upper surface 3 and the lower surface 5 are not limited to the above-mentioned form. In the example shown in FIG. 1, the upper surface 3 and the lower surface 5 are substantially quadrangular, but for example, the upper surface 3 and the lower surface 5 may be triangular, pentagonal, hexagonal, or octagonal, respectively. Further, although the upper surface 3 in the example shown in FIG. 1 is substantially square, the shape of the quadrangle is not limited to such a shape. The upper surface 3 may be, for example, a rhombus or a rectangle.

As shown in FIG. 3, the side surface 7 is located between the upper surface 3 and the lower surface 5, and may be connected to the upper surface 3 and the lower surface 5. As described above, when the lower surface 5 is one size smaller than the upper surface 3, the shape of the side surface 7 when viewed from the front (hereinafter, also referred to as side view) is trapezoidal. In other words, as shown in FIG. 3, the vertical side of the side surface 7 in the side view may be inclined so as to approach the central axis X1 from the side of the upper surface 3 toward the side of the lower surface 5.

The maximum width of the upper surface 3 when viewed from above may be set to, for example, 6 to 25 mm. Further, the height from the lower surface 5 to the upper surface 3 may be set to, for example, 1 to 10 mm. Here, the height from the lower surface 5 to the upper surface 3 means the length in the direction parallel to the central axis X1 between the upper end of the upper surface 3 and the lower end of the lower surface 5.

The configuration of the upper surface 3, the lower surface 5, and the side surface 7 is not limited to the above configuration. For example, the lower surface 5 may have the same shape as the upper surface 3, and the outer circumference of the lower surface 5 may overlap with the outer circumference of the upper surface 3 when viewed through a plane. In this case, the side surface 7 may be positioned so as to be orthogonal to the lower surface 5.

Further, the relative positional relationship between the upper surface 3, the lower surface 5 and the side surface 7 is not limited to the above configuration. Specifically, the upper surface 3 is not always located upward when the surface 3 is mounted on the drill or is being machined. Further, the lower surface 5 is not always located downward when the lower surface 5 is mounted on the drill or is being machined.

The insert 1 may have a through hole 11 that opens on the upper surface 3. The through hole 11 shown in FIG. 1 is formed from the center of the upper surface 3 toward the center of the lower surface 5. The through hole 11 may be used for inserting a screw when screwing and fixing the insert 1 to the holder of the drill. The lower surface 5 may be a flat surface, and the extending direction of the through hole 11, in other words, the penetrating direction may be orthogonal to the lower surface 5. The opening of the through hole 11 on the upper surface 3 is hereinafter referred to as a first opening 11a.

The cutting edge 9 may be located at least a part of the ridgeline where the upper surface 3 and the side surface 7 intersect. The cutting edge 9 can be used for cutting the work material in the cutting process. In the example shown in the figure, the cutting edge 9 is located at least on the first side 3a. The cutting edge 9 may be located on each side and each corner of the upper surface 3 including the first side 3a.

The upper surface 3 may have a first region 13, a second region 15, a third region 17, a fourth region 19, and a fifth region 21. The first region 13 in the example shown in FIG. 2 is located along the first portion 3aa and is inclined downward as the distance from the first portion 3aa is increased. The second region 15 in the example shown in FIG. 2 is located along the second portion 3ab and is inclined downward as the distance from the second portion 3ab is increased. The third region 17 in the example shown in FIG. 2 is located along the third portion 3ac and is inclined downward as the distance from the third portion 3ac is increased.

As described above, the first region 13, the second region 15, and the third region 17 are each inclined downward as they move away from the first side 3a, and can function as a so-called rake surface. ..

Further, the fourth region 19 in the example shown in FIG. 2 is located between the second region 15 and the first opening 11a, and the fifth region 21 in the example shown in FIG. 2 is the third region 17 and the first opening. It is located between 1 openings 11a. At this time, in the example shown in FIG. 2, the inclination angle of the fourth region 19 is smaller than that of the second region 15, and the inclination angle of the fifth region 21 is smaller than that of the third region 17.

As described above, the fourth region 19 and the fifth region 21 having relatively small inclination angles may be located between the second region 15 and the third region 17 and the first opening 11a, respectively. When the upper surface 3 has the fourth region 19 and the fifth region 21 as described above, it is possible to improve the chip discharge property while securing the region of the rake face.

When the insert 1 of the embodiment is used as an insert on the inner peripheral side of the drill and cutting is performed by the cutting edge 9 located on the first side 3a, the chips are straight in the direction orthogonal to the first side 3a. It is easy to be curled into a conical shape instead of advancing.

This is because when the first angle 3b is located closer to the rotation axis of the drill than the second angle 3c, the rotation speed of the third part 3ac is faster than the rotation speed of the second part 3ab. ing. Since the amount of chips generated at the third site 3ac is larger than the amount of chips generated at the second site 3ab, the chips are likely to be curled into a conical shape due to the difference in these amounts. In a chip curled into a conical shape, both ends in the width direction of the chip are easily hangnailed, so that the outer peripheral end of the chip may come into contact with the screw or the first opening 11a, and the chip may be clogged.

However, in the insert 1 of the embodiment, the fifth region 21 having a smaller inclination angle than the third region 17 is located between the third region 17 and the first opening 11a. Therefore, when the chips generated at the third portion 3ac come into contact with the fifth region 21, the end portion of the chips is less likely to come into contact with the screw and the first opening 11a.

Further, in the insert 1 of the embodiment, since the fourth region 19 having a smaller inclination angle than the second region 15 is located between the second region 15 and the first opening 11a, the cutting edge 9 has a cutting edge 9. Along with ensuring the wall thickness, it is possible to secure a wide space that can function as a rake face. Therefore, clogging of chips due to a small curl diameter of chips is unlikely to occur.

For the above reasons, the insert 1 of the present embodiment can improve the chip discharge property while securing the area of the rake face. Since the fourth region 19 may have a smaller inclination angle than the second region 15, it may be a flat surface parallel to the lower surface 5. Since the fifth region 21 also needs to have a smaller inclination angle than the third region 17, it may be a flat surface parallel to the lower surface 5. That is, the inclination angles of the fourth region 19 and / or the fifth region 21 may be 0 °, respectively.

Examples of the material of the insert 1 include cemented carbide and cermet. Examples of the composition of the cemented carbide include WC-Co, WC-TiC-Co and WC-TiC-TaC-Co. Here, WC, TiC, and TaC are hard particles, and Co is a bonded phase.

Cermet is a sintered composite material in which a metal is composited with a ceramic component. Specifically, examples of the cermet include a titanium compound containing titanium carbide (TiC) or titanium nitride (TiN) as a main component.

The surface of the insert 1 may be coated with a coating using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the coating include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN) and alumina (Al ₂ O ₃ ).

As already shown, the upper surface 3 may have a first region 13, a second region 15, a third region 17, a fourth region 19, and a fifth region 21. Here, in the front view of the upper surface 3, the minimum value of the width W1c of the third region 17 in the direction orthogonal to the third region 3ac is the minimum value of the width W1b of the second region 15 in the direction orthogonal to the second region 3ab. It may be narrower. When the minimum value of the width W1c is narrower than the minimum value of the width W1b, the chip discharge property is further high.

When the width W1c of the third region 17 is narrower than the width W1b of the second region 15, the fifth region 21 is likely to be secured wider than the fourth region 19. When the first corner 3b is located closer to the rotation axis of the drill than the second corner 3c, the amount of chips generated at the third part 3ac is larger than the amount of chips generated at the second part 3ab, and the third part The traveling direction of chips generated in 3ac tends to be unstable. When the fifth region 21 is wider than the fourth region 19, the fifth region 21 is likely to come into contact with the chips generated in the third region 3ac. Therefore, the dischargeability of chips can be further improved.

The heights of the fourth region 19 and the fifth region 21 do not have to be limited to a specific value. However, when the fourth region 19 and the fifth region 21 are located on the same virtual plane, the chip discharge property is further high.

When these flat surfaces are located on the same virtual plane and at the same height position, the chips generated on the first side 3a are located on either the fourth region 19 or the fifth region 21. It is easy to come into contact with both the fourth region 19 and the fifth region 21. As a result, both ends of the chip are less likely to come into contact with the screw and the first opening 11a, so that the chip dischargeability is further improved. Note that the fact that the fourth region 19 and the fifth region 21 are located on the same virtual plane does not mean that these flat surfaces are exactly located on the same virtual plane, and the fourth region is not required to be located on the same virtual plane. The height positions of the regions 19 and the fifth region 21 may be displaced by about 3% with respect to the height from the lower surface 5 to the upper surface 3 of the insert 1.

As already shown, the first side 3a in the example shown in FIG. 2 has a first part 3aa, a second part 3ab, and a third part 3ac. At this time, the widths of the first site 3aa, the second site 3ab, and the third site 3ac are not limited to specific values. When the width W2a of the first portion 3aa is narrower than the widths W2b and W2c of the second portion 3ab and the third portion 3ac, the fourth region 19 and the fifth region 21 are likely to be widely secured. As a result, both ends of the chip are likely to come into contact with the fourth region 19 and the fifth region 21, and are less likely to come into contact with the screw or the first opening 11a, so that the possibility of the chip being clogged is further reduced.

The shapes of the first site 3aa, the second site 3ab, and the third site 3ac are not particularly limited. For example, as shown in FIG. 3, the third portion 3ac may have a concave shape in the side view. When the third portion 3ac has a concave shape, the chips tend to be curved so as to correspond to the concave shape of the third portion 3ac. Therefore, it is difficult for the outer peripheral end of the chip to come into contact with the screw or the first opening 11a.

As shown in FIG. 3, the third portion 3ac may have a concave shape in the side view, while the third portion 3ac may have a convex shape in the top view as shown in FIG. Coupled with the effect that the third portion 3ac has a concave shape in the side view, the chips are more likely to be curved. Therefore, it is more difficult for the outer peripheral end of the chip to come into contact with the screw or the first opening 11a.

Further, as shown in FIG. 3, the second portion 3ab may have a linear shape in the side view. When the first angle 3b is located closer to the rotation axis of the drill than the second angle 3c, the rotation speed of the second part 3ab is relatively slow as compared with the first part 3aa and the third part 3ac. Therefore, it is desired that the second portion 3ab has higher machinability than the first portion 3aa and the third portion 3ac. When the second portion 3ab has a linear shape in the side view, the work material can be smoothly cut because the second portion 3ab has high machinability.

As shown in FIG. 3, the second portion 3ab may have a linear shape in the side view, and the third portion 3ac may have a linear shape in the top view as shown in FIG. When the second portion 3ab has a linear shape when viewed from above, the work material can be smoothly cut because the second portion 3ab has high machinability.

The first region 13 on the upper surface 3 is inclined downward as the distance from the first side 3a increases. At this time, the first region 13 may be composed of one flat surface region, or may be composed of a plurality of surface regions having different inclination angles from each other. The second region 15 and the third region 17 are also inclined downward as they move away from the first side 3a, respectively. At this time, the second region 15 and the third region 17 may each be composed of one flat surface region, or may be composed of a plurality of surface regions having different inclination angles from each other.

If the tilt angle in the target region is not constant, the maximum value of the tilt angle in the target region is evaluated as the “tilt angle”.

The first region 13 located between the second region 15 and the third region 17 may be separated from the first opening 11a or may be connected to the first opening 11a. When the first region 13 is connected to the first opening 11a, a large space of the first region 13 that can function as a rake face can be secured.

In the examples shown in FIGS. 2 and 4, the first region 13, the second region 15, and the third region 17 are each composed of a plurality of surface regions. Specifically, the first region 13 is located between the first outer region 13a, the first outer region 13a, and the first opening 11a, and has a larger inclination angle than the first outer region 13a. It has an inner region 13b. The second region 15 has a second outer region 15a and a second inner region 15b located between the second outer region 15a and the fourth region 19 and having a larger inclination angle than the second outer region 15a. is doing. Further, the third region 17 is located between the third outer region 17a and the third outer region 17a and the fourth region 19, and has a larger inclination angle than the third outer region 17a with the third inner region 17b. have.

When the first region 13, the second region 15 and the third region 17 are each composed of a plurality of surface regions as described above, chips are chipped in the first region 13, the second region 15 and the third region 17. Since it is possible to reduce the contact area, the chip discharge property is high.

Further, as in the example shown in FIG. 7, the second virtual straight line X3 in contact with the third outer region 17a may intersect the fifth region 21 in the cross section orthogonal to the third portion 3ac. When the upper surface 3 has the above configuration, the chips generated at the third portion 3ac easily come into contact with the fifth region 21. Therefore, the dischargeability of chips is even higher.

The inclination angles of the first outer region 13a, the first inner region 13b, the second outer region 15a, the second inner region 15b, the third outer region 17a, and the third inner region 17b on the upper surface 3 are limited to specific values, respectively. Although it is not a thing, for example, it may be set as follows.

As an example shown in FIG. 6, the inclination angle θ2b of the second inner region 15b may be larger than the inclination angle θ3b of the third inner region 17b shown in FIG. 7. When the inclination angles of the second inner region 15b and the third inner region 17b are set as described above, the chip discharge property is further high. This is because when the inclination angle θ2b of the second inner region 15b is relatively large, it is difficult for chips to come into contact with the second inner region 15b.

At this time, the inclination angle θ1b of the first inner region 13b may be smaller than the inclination angle θ2b of the second inner region 15b and larger than the inclination angle θ3b of the third inner region 17b. When the inclination angle θ1b of the first inner region 13b is set as described above, the inclination angle suddenly changes between the first inner region 13b, the second inner region 15b, and the third inner region 17b. It is unlikely that the strength of the cutting edge 9 will decrease due to the above. Therefore, the durability of the insert 1 is high.

Further, as in the example shown in FIG. 6, the inclination angle θ2a of the second outer region 15a may be larger than the inclination angle θ3a of the third outer region 17a shown in FIG. 7. When the inclination angles of the second outer region 15a and the third outer region 17a are set as described above, the chip discharge property is high. Since the inclination angle θ2a of the second outer region 15a is relatively large, the traveling direction of chips generated at the second portion 3ab located near the rotation axis of the drill is stabilized. Further, since the inclination angle θ3a of the third outer region 17a is relatively small, chips tend to smoothly advance toward the fifth region 21. For these reasons, chip evacuation is even higher.

At this time, the inclination angle θ1a of the first outer region 13a may be smaller than the inclination angle θ2a of the second outer region 15a and larger than the inclination angle θ3a of the third outer region 17a. When the inclination angle θ1a of the first outer region 13a is set as described above, the inclination angle suddenly changes between the first outer region 13a, the second outer region 15a, and the third outer region 17a. It is less likely that the chips will be clogged due to the above. Therefore, the dischargeability of chips is even higher.

Further, as in the example shown in FIGS. 6 and 7, the second inner region 15b and the second outer region 15a may be connected, and the third inner region 17b and the third outer region 17a may be connected. Then, the maximum value L12 of the height from the fourth region 19 at the boundary between the second inner region 15b and the second outer region 15a is from the fifth region 21 at the boundary between the third inner region 17b and the third outer region 17a. It is higher than the maximum height L13. When the second region 15 and the third region 17 are configured as described above, the second inner region 15b and the third outer region 17a are respectively widely secured, so that the chip discharge property is further high.

Since the second inner region 15b having a larger inclination angle than the second outer region 15a is secured widely, the traveling direction of the chips generated at the second portion 3ab located near the rotation axis of the drill is stable. Further, since the third outer region 17a having an inclination angle smaller than that of the third inner region 17b is widely secured, chips generated at the third portion 3ac can easily move toward the fifth region 21. For these reasons, chip evacuation is even higher.

The upper surface 3 may have a portion other than the above-mentioned region. For example, as shown in FIGS. 5 to 7, the first region 13, the second region 15, and the third region 17 may each have a land surface 23 in a region along the first side.

<Drill>
Next, the drill 101 of the embodiment will be described with reference to the drawings.

As shown in FIGS. 8 to 10, the drill 101 of the embodiment has a holder 103, an insert 105 for an inner blade, and an insert 107 for an outer blade. Hereinafter, an example in which the insert 1 of the embodiment is used for the insert 105 for the inner blade will be described.

The holder 103 has a main body 109, a first chip discharge groove 111 (hereinafter, also simply referred to as a first groove 111), and a second chip discharge groove 113 (hereinafter, also simply referred to as a second groove 113). is doing. The main body 109 has a rod shape that can rotate around the rotation axis Y1. The main body 109 in the example shown in FIG. 8 has a rod shape extending from the first end to the second end. The main body 109 rotates around the rotation axis Y1 around the rotation axis Y1 during cutting. In the following description, the first end is regarded as the tip and the second end is regarded as the rear end.

Although not particularly shown, when the drill 1 is viewed from the tip, the rotation locus of the cutting edge 9 in the insert 105 for the inner blade and the rotation locus of the cutting edge in the insert 107 for the outer blade partially overlap each other, and It overlaps with the whole body portion 109. Drilling is performed by the cutting edges of the insert 105 for the inner blade and the insert 107 for the outer blade thus formed.

The main body 109 in the embodiment has a grip 115 called a shank, which is gripped by a rotating spindle or the like of a machine tool (not shown), and a body located on the tip side of the grip 115. ) Is provided with a cutting portion 117. The grip portion 115 is a portion designed according to the shape of a spindle or the like in a machine tool. The cutting portion 117 is a portion to which the inserts 105 and 107 are mounted at the tip thereof, and is a portion having a main role in cutting the work material. The arrow Y2 indicates the rotation direction of the main body 109.

A first pocket 119 and a second pocket 121 are provided on the tip end side of the cutting portion 117 in the main body portion 109. The first pocket 119 is a recess provided on the center side of the tip of the cutting portion 117, and is a portion to which the insert 105 for the inner blade is mounted. The second pocket 121 is a recess provided on the outer peripheral side of the tip of the cutting portion 117, and is a portion to which the insert 107 for the outer blade is mounted. The first pocket 119 and the second pocket 121 are provided apart from each other so that the insert 105 for the inner blade and the insert 107 for the outer blade do not come into contact with each other.

The insert 105 is located in the first pocket 119 and the insert 107 is located in the second pocket 121. At this time, the insert 105 for the inner blade is mounted so that the second cutting edge of the insert 105 for the inner blade intersects the rotation axis Y1. In the present disclosure, an insert different from the above-mentioned insert 1 is used as the insert 107 for the outer blade, but the above-mentioned insert 1 may also be used as the insert 107 for the outer blade.

The first groove 111 extends spirally around the rotation axis Y1 from the insert 105 for the inner blade toward the rear end side of the main body portion 109. Further, the second groove 113 extends spirally around the rotation axis Y1 from the insert 107 for the outer blade toward the rear end side of the main body portion 109. In the embodiment, the first groove 111 and the second groove 113 are provided in the cutting portion 117 of the main body portion 109, and are not provided in the grip portion 115.

In the drill 101 of the embodiment, for example, the outer diameter of the cutting portion 117 is set to 6 mm to 42.5 mm. Further, in the drill 101 of the present embodiment, for example, when the length of the axis line (the length of the cutting portion 117) is L and the diameter (the outer diameter of the cutting portion 117) is D, L = 2D to 12D is set. Will be done.

As the material of the main body 109, steel, cast iron, aluminum alloy, or the like can be used. Steel is suitable in terms of high toughness.

The first groove 111 has a main purpose of discharging chips generated by the cutting edge of the insert 105 for the inner blade. At the time of cutting, the chips formed by the insert 105 for the inner blade are discharged to the rear end side of the main body 109 through the first groove 111. Further, the second groove 113 has a main purpose of discharging chips generated by the cutting edge of the insert 107 for the outer blade. At the time of cutting, the chips formed by the insert 107 for the outer blade are discharged to the rear end side of the main body 109 through the second groove 113.

The depth of each of the first groove 111 and the second groove 113 can be set to about 10 to 40% with respect to the outer diameter of the cutting portion 117. Here, the depth of the first groove 111 and the second groove 113 is the radius of the cutting portion 117, which is the distance between the bottom of the first groove 111 and the second groove 113 and the rotation axis Y1 in the cross section orthogonal to the rotation axis Y1. Means the value subtracted from. Therefore, the diameter of the core thickness (web thickness) indicated by the diameter of the inscribed circle in the cross section orthogonal to the rotation axis Y1 in the cutting portion 117 is set to about 20 to 80% with respect to the outer diameter of the cutting portion 117. Will be done. Specifically, for example, when the outer diameter D of the cutting portion 117 is 20 mm, the depths of the first groove 111 and the second groove 113 can be set to about 2 to 8 mm.

<Manufacturing method of machined product>
Next, the method of manufacturing the machined product according to the embodiment will be described in detail with reference to the case where the drill 101 according to the above-described embodiment is used as an example. Hereinafter, description will be made with reference to FIGS. 11 to 13. In FIGS. 11 to 13, the portion on the rear end side of the grip portion of the drill 101 is omitted.

The method for manufacturing a machined product according to an embodiment includes the following steps (1) to (4).

(1) A step of arranging the drill 101 above the prepared work material 201 (see FIG. 11).

(2) A step of rotating the drill 101 around the rotation axis Y1 in the direction of the arrow Y2 and bringing the drill 101 closer to the work material 201 in the Z1 direction (see FIGS. 11 and 12).

This step can be performed, for example, by fixing the work material 201 on the table of the machine tool to which the drill 101 is attached and bringing the drill 101 closer in a rotated state. In this step, the work material 201 and the drill 101 may be relatively close to each other, and the work material 201 may be brought close to the drill 101.

(3) By bringing the drill 101 closer to the work material 201, the cutting edge 9 of the rotating drill 101 is brought into contact with a desired position on the surface of the work material 201, and a machined hole is made in the work material 201. Step of forming 203 (see FIG. 12).

In this step, from the viewpoint of obtaining a good finished surface, a part of the cut portion of the drill 101 on the rear end side may be set so as not to come into contact with the work material 201. That is, by making this part of the region function as a region for chip discharge, it is possible to achieve excellent chip discharge through the region.

(4) A step of separating the drill 101 from the work material 201 in the Z2 direction (see FIG. 13).

In this step as well, as in the step (2) described above, the work material 201 and the drill 101 may be relatively separated from each other, and for example, the work material 201 may be separated from the drill 101.

By going through the above steps, a machined product having a machined hole 203 can be obtained.

When the work material 201 is cut a plurality of times as shown above, for example, when a plurality of machined holes 203 are formed in one work material 201, the drill 101 is rotated. The process of bringing the cutting edge 9 of the drill 101 into contact with different parts of the work material 201 while maintaining the state may be repeated.

Although the embodiments of the insert and the drill have been exemplified above, it is needless to say that the insert and the drill of the present disclosure are not limited to the above-described embodiment and may be arbitrary as long as they do not deviate from the gist of the present disclosure. stomach.

1 ... Cutting insert (insert)
3 ... Top surface 3a ... First side 3aa-First part 3ab-Second part 3ac-Third part 3b ... First angle 3c ... Second angle 5 ... Bottom surface 7 ... Side surface 9.・ ・ Cutting edge 11 ・ ・ ・ Through hole 11a ・ ・ First opening 13 ・ ・ ・ First area 13a ・ ・ First outer area 13b ・ ・ First inner area 15 ・ ・ ・ Second area 15a ・ ・ Second Outer region 15b ... 2nd inner region 17 ... 3rd region 17a ... 3rd outer region 17b ... 3rd inner region 19 ... 4th region 21 ... 5th region 23 ... Land surface 101 ... Drill 103 ... Holder 105 ... Insert for inner blade 107 ... Insert for outer blade 109 ... Main body 111 ... First chip discharge groove (first groove)
113 ... Second chip discharge groove (second groove)
115 ... Grip part 117 ... Cutting part 119 ... First pocket 121 ... Second pocket 201 ... Work material

Claims (12)

A holder having a rod shape extending from the first end to the second end along the rotation axis and having an inner blade pocket and an outer blade pocket located on the side of the first end, respectively.
The inner blade insert attached to the inner blade pocket and
A drill provided with an outer blade insert mounted in the outer blade pocket.
The insert for the inner blade is
A first side and an upper surface having a first corner and a second corner adjacent to the first side,
It is provided with a through hole that opens on the upper surface.
The first corner is located closer to the axis of rotation than the second corner.
The first side is
The first part located in the center of the length of the first side and
The first part and the second part located between the first corners,
It has a first part and a third part located between the second corners.
The upper surface is
A first region located along the first site and sloping downward as it moves away from the first site.
A second region located along the second site and sloping downward as it moves away from the second site.
A third region located along the third site and sloping downward as it moves away from the third site.
A fourth region located between the second region and the opening of the through hole and having a smaller inclination angle than the second region,
It has a fifth region located between the third region and the opening portion and having a smaller inclination angle than the third region.
The first region and the opening portion are connected to each other.
The second region has a second outer region and a second inner region located between the second outer region and the fourth region and having a larger inclination angle than the second outer region.
The third region has a third outer region and a third inner region located between the third outer region and the fifth region and having a larger inclination angle than the third outer region.
A drill in which an extension of the surface of the third outer region intersects the fifth region in a cross section orthogonal to the third portion. The drill according to claim 1, wherein the inclination angle of the second inner region is larger than the inclination angle of the third inner region. The first region has a first outer region and a first inner region located between the first outer region and the opening portion and having a larger inclination angle than the first outer region.
The drill according to claim 2, wherein the inclination angle of the first inner region is smaller than the inclination angle of the second inner region and larger than the inclination angle of the third inner region. The drill according to any one of claims 1 to 3, wherein the inclination angle of the second outer region is larger than the inclination angle of the third outer region. The first region has a first outer region and a first inner region located between the first outer region and the opening portion and having a larger inclination angle than the first outer region.
The drill according to claim 4, wherein the inclination angle of the first outer region is smaller than the inclination angle of the second outer region and larger than the inclination angle of the third outer region. The second inner region and the second outer region are connected, and the third inner region and the third outer region are connected.
The maximum value of the height of the boundary between the second inner region and the second outer region from the fourth region is the height of the boundary between the third inner region and the third outer region from the fifth region. The drill according to any one of claims 1 to 5, which is higher than the maximum value. Any of claims 1 to 6, wherein in the front view of the upper surface, the width of the third region in the direction orthogonal to the third portion is narrower than the width of the second region in the direction orthogonal to the second portion. Or the drill described in item 1 . The drill according to any one of claims 1 to 7, wherein the fourth region and the fifth region are located on the same virtual plane. The drill according to any one of claims 1 to 8, wherein the width of the first portion is narrower than the width of the second portion and the third portion. The lower surface located on the opposite side of the upper surface and the lower surface
Further having a side surface located between the upper surface and the lower surface,
The drill according to any one of claims 1 to 9, wherein the second portion has a linear shape and the third portion has a concave shape in a front view of the side surface. The drill according to claim 10, wherein the second portion has a linear shape and the third portion has a convex shape in a front view of the upper surface. The step of rotating the drill according to any one of claims 1 to 11.
The process of bringing the rotating drill into contact with the work material,
A method for manufacturing a machined product, comprising a step of separating the drill from the work material.

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