CN115135440B

CN115135440B - End mill and method for manufacturing cut product

Info

Publication number: CN115135440B
Application number: CN202180016346.9A
Authority: CN
Inventors: 黑田雅彦
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2020-02-28
Filing date: 2021-02-25
Publication date: 2024-08-13
Anticipated expiration: 2041-02-25
Also published as: JPWO2021172414A1; WO2021172414A1; JP7417707B2; CN115135440A

Abstract

The end mill has a body extending along an axis of rotation from a first end to a second end. The main body has: a chisel edge at the first end; a first cutting edge extending from the chisel edge toward the outer periphery; a first relief surface connected to the first cutting edge at a rear side of the rotation direction of the rotation shaft; a first cutter groove connected to the first cutting edge at the front in the rotation direction; and a discharge slot located closer to the second end than the first sipe. The first pocket has a bottom, a first wall surface located between the bottom and the first cutting edge, and a second wall surface located forward in the rotational direction with respect to the bottom. The first wall extends to a position closer to the second end than the second wall.

Description

End mill and method for manufacturing cut product

Cross-reference to related applications

The present application claims priority from japanese patent application 2020-033543, filed on 28 months 2 in 2020, and the entire disclosure of this prior application is incorporated herein by reference.

Technical Field

The present disclosure relates generally to rotary tools used in rotary cutting machining of a workpiece. The rotary cutter may be, for example, an end mill. Examples of the end mill include a square end mill and a ball end mill.

Background

As a cutting tool used for performing a rotary cutting process on a workpiece, for example, a ball nose end mill described in japanese patent application laid-open No. 2010-105093 (patent document 1) is cited. The ball nose end mill described in patent document 1 is an example of an end mill. The end mill described in patent document 1 has a cutting edge, a first center groove portion, a second center groove portion, and a chip discharge groove. The first central groove part and the second central groove part are respectively in the shape of V-shaped grooves.

In patent document 1, the first and second central groove portions have V-groove shapes. Therefore, the chip may not pass over the first center groove portion and may be blocked in the first center groove portion at a position distant from the cutting edge.

Disclosure of Invention

An end mill of an undefined aspect of the present disclosure has a body extending along an axis of rotation from a first end to a second end. The main body has: a chisel edge at the first end; a first cutting edge and a second cutting edge extending from the chisel edge toward the outer periphery, respectively; a first flank surface connected to the first cutting edge at a rear side of the rotation direction of the rotation shaft; a second flank surface connected to the second cutting edge at a rear side of the rotation direction of the rotation shaft; a first pocket connected to the first cutting edge in front of the rotation direction; and a discharge slot located closer to the second end than the first sipe. The first sipe has: a bottom; a first wall surface located between the bottom and the first cutting edge; and a second wall surface located forward of the rotation direction with respect to the bottom. The first wall extends to a position closer to the second end than the second wall.

Drawings

Fig. 1 is a perspective view showing an end mill according to an undefined embodiment.

Fig. 2 is a plan view of the end mill shown in fig. 1, as seen from a first end side.

Fig. 3 is a side view of the end mill shown in fig. 2, as viewed from the A1 direction.

Fig. 4 is a side view of the end mill shown in fig. 2, as viewed from the A2 direction.

Fig. 5 is a side view of the end mill shown in fig. 2, as viewed from the A3 direction.

Fig. 6 is a side view of the end mill shown in fig. 2, as viewed from the A4 direction.

Fig. 7 is an enlarged view of the region B1 shown in fig. 3.

Fig. 8 is an enlarged view of the same region as that shown in fig. 7.

Fig. 9 is a cross-sectional view of a section IX of the end mill shown in fig. 8.

Fig. 10 is a cross-sectional view of an X-section of the end mill shown in fig. 8.

Fig. 11 is a cross-sectional view of section XI of the end mill shown in fig. 8.

Fig. 12 is a cross-sectional view of the XII cross-section of the end mill shown in fig. 8.

Fig. 13 is an enlarged view of the region B2 shown in fig. 5.

Fig. 14 is a schematic view showing a step in a method for manufacturing a machined product according to an embodiment, which is not limited.

Fig. 15 is a schematic view showing a step in a method for manufacturing a machined product according to an embodiment, which is not limited.

Fig. 16 is a schematic view showing a step in a method for manufacturing a machined product according to an embodiment, which is not limited.

Detailed Description

The end mill 1 according to an undefined embodiment will be described in detail with reference to the drawings. In the non-limiting embodiment, a ball nose end mill may be used as an example of the end mill. However, the end mill is not limited to the ball end mill, and may be, for example, a square end mill.

In the drawings referred to below, only the main components among the components constituting the non-limiting embodiment are shown for the sake of convenience of description. Accordingly, the end mill 1 may include any constituent member not shown in the drawings referred to in the present specification. The dimensions of the components in the drawings do not faithfully show the actual dimensions of the constituent components and the dimensional ratios of the components. These are also the same in the method for producing a machined product described later.

As shown in fig. 1 and the like, the end mill 1 may be provided with a cylindrical body 3 having a rotation axis R1 and extending from a first end 3a to a second end 3 b. In general, the first end 3a is referred to as a "front end" and the second end 3b is referred to as a "rear end".

The end mill 1 in the non-limiting example shown in fig. 1 may have a rod-shaped body 3 extending along the rotation axis R1 from the first end 3a to the second end 3 b. The main body 3 is rotatable in the direction of arrow R2 around a rotation axis R1 as in the non-limited example shown in fig. 1 during cutting of a workpiece for manufacturing a cut product.

In the non-limiting example shown in fig. 1, the lower left end of the main body 3 may be a first end 3a, and the upper right end may be a second end 3b. In the non-limiting example shown in fig. 3 to 6, the left end of the main body 3 may be the first end 3a, and the right end may be the second end 3b.

Fig. 3 to 6 are views showing a state in which the end mill 1 shown in fig. 2 is rotated by a predetermined angle in the rotation direction R2. Fig. 3 is a view of the end mill 1 shown in fig. 2 as seen from the A1 direction. Fig. 4 is a view of the end mill 1 shown in fig. 2 as seen from the A2 direction. Fig. 4 is a view from a direction offset by 90 ° with respect to fig. 3. Fig. 5 is a view of the end mill 1 shown in fig. 2 as seen from the A3 direction. Fig. 5 is a view from a direction offset by 90 ° with respect to fig. 4. Fig. 6 is a view of the end mill 1 shown in fig. 2 as seen from the A4 direction. Fig. 6 is a view from a direction offset by 90 ° with respect to fig. 5.

The main body 3 in the non-limiting example shown in fig. 1 may have a cylindrical shape. The columnar shape includes not only a columnar shape in a strict sense but also a shape having minute irregularities, curves, or the like. The shape of the main body 3 is not limited to a cylindrical shape.

The outer diameter D of the body 3 may be set to, for example, 4mm to 25mm. When the length of the main body 3 along the direction of the rotation axis R1 is L, the relationship between L and D can be set to l=4d to 15D, for example. At this time, the outer diameter of the main body 3 may be constant from the first end 3a side to the second end 3b side, or may be variable. For example, the outer diameter of the main body 3 may be smaller from the first end 3a side to the second end 3b side.

The main body 3 may have a chisel edge 5, a first cutting edge 7, a second cutting edge 9, a first flank 11, a second flank 13, a first pocket 15, and a first discharge groove 17.

The chisel edge 5 may be located at the first end 3a of the body 3. The chisel edge 5 may intersect the rotation axis R1. In other words, the chisel edge 5 may include the rotation axis R1 in front view from the first end 3a in the direction along the rotation axis R1. The front view from the first end 3a along the direction of the rotation axis R1 is also generally referred to as a front view.

The first cutting edge 7 and the second cutting edge 9 may be located near the first end 3a, respectively, and may also extend from the chisel edge 5 toward the outer periphery, respectively. The first cutting edge 7 may be connected to one end of the chisel edge 5, and the second cutting edge 9 may be connected to the other end of the chisel edge 5. The workpiece can be cut by the chisel edge 5, the first cutting edge 7, and the second cutting edge 9.

The first cutting edge 7 and the second cutting edge 9 may be located at positions where the rake surface and the flank surface (the first flank surface 11 and the second flank surface 13) intersect. On the other hand, the chisel edge 5 may be located where the flank surfaces 11, 13 intersect. The cutting edge formed by the chisel edge 5, the first cutting edge 7, and the second cutting edge 9 may have a shape rotationally symmetrical by 180 ° about the rotation axis R1 when viewed from the tip.

In the case where the end mill 1 is a ball end mill as in the non-limited example shown in fig. 1, the first cutting edge 7 and the second cutting edge 9 may have a convex curve shape when viewed from the side as shown in fig. 3 and the like. In the case where the end mill 1 is a square end mill as described above, the first cutting edge 7 and the second cutting edge 9 may have a straight line shape extending in a direction orthogonal to the rotation axis R1.

The first flank 11 may be connected to the first cutting edge 7 rearward of the rotation direction R2 of the rotation shaft R1. The first flank surface 11 may be a flat surface or may be a curved surface. When the first flank 11 is a plane, the first flank 11 may be formed of 1 plane, or may be formed of a plurality of planes.

The second flank surface 13 may be connected to the second cutting edge 9 rearward of the rotation direction R2 of the rotation shaft R1. The second flank surface 13 may be a flat surface or a curved surface, as in the first flank surface 11. In the case where the second flank surface 13 is a plane, the second flank surface 13 may be formed of 1 plane, or may be formed of a plurality of planes.

The first pocket 15 may also be connected to the first cutting edge 7 in front of the rotation direction R2. That is, the first cutting edge 7 may be located at a position where the first flank 11 intersects the first pocket 15. The first sipe 15 may have a function of improving the strength of the first cutting edge 7.

The first sipe 15 may extend from the outer peripheral surface of the main body 3 substantially toward the rotation axis R1. At this time, the first sipe 15 may be closer to the first end 3a toward the rotation axis R1. As shown in the figure, the first sipe 15 may be a V-groove shape, and may have a first bottom 19, a first wall surface 21, and a second wall surface 23.

The first wall surface 21 may also be located between the first bottom 19 and the first cutting edge 7. Here, the first wall surface 21 may be connected to the first cutting edge 7 in front of the rotation direction R2. In this case, the first wall surface 21 may also function as the rake surface. The second wall surface 23 may be located forward of the first bottom 19 in the rotation direction R2. In this case, the second wall surface 23 may also function as a chip breaking wall for bending chips. The first bottom 19 may be positioned between the first wall surface 21 and the second wall surface 23.

In the case where the first sipe 15 having a V-groove shape is viewed in a cross section orthogonal to the extending direction of the first sipe 15, the first wall surface 21 may be a straight line or may be a curved line. The second wall surface 23 may be a straight line or a curved line in the same cross section. Moreover, in the same cross section, the first bottom 19 may also be a concave curve. In this case, since cracks due to cutting load are less likely to occur in the first bottom portion 19, the durability of the end mill 1 can be improved.

The V-groove-shaped first sipe 15 may extend straight, or may extend spirally around the rotation axis R1 as in the non-limited example shown in fig. 1. The torsion angle of the first sipe 15 in the case where the first sipe 15 extends in a spiral shape is not limited to a specific value, and may be set to 5 ° to 60 °. In the case where the first sipe 15 extends in a spiral shape, the first wall surface 21 and the second wall surface 23 may be curved surfaces, respectively, and may be represented by straight lines in the cross section.

The first discharge groove 17 may be located closer to the second end 3b than the first sipe 15. The first discharge flute 17 may have a function of discharging the chips generated by the first cutting edge 7 toward the second end 3b and discharging the chips to the outside. The first discharge groove 17 extends toward the second end 3b, but need not extend to the second end 3b, and may be located away from the second end 3b.

The first discharge groove 17 may extend straight toward the second end 3b, or may extend spirally around the rotation axis R1 as in the non-limited example shown in fig. 1. The torsion angle of the first discharge groove 17 in the case where the first discharge groove 17 extends in a spiral shape is not limited to a specific value, and may be set to 5 ° to 60 °.

The end mill 1 of the non-limited example shown in fig. 1 is a tool used in right rotation, and therefore the first gash 15 and the first discharge gash 17 are twisted right, but the end mill 1 is not limited thereto. For example, even if the cutter is used in the left rotation and the first sipe 15 and the first discharge groove 17 are left-twisted, there is no problem.

As an example, which is not limited, as shown in fig. 7, the first wall surface 21 may extend to a position closer to the second end 3b than the second wall surface 23. In this case, the chips flowing on the first wall surface 21 easily advance toward the portion located forward of the first sipe 15 in the rotation direction R2 in the region of the first wall surface 21 located closer to the second end 3b than the second wall surface 23. Therefore, the chips in the first sipe 15 are not likely to be clogged, and the chip discharge performance is high. As a portion located forward of the first sipe 15 in the rotational direction R2, for example, a first discharge groove 17 and a second sipe 25 described below as an undefined example shown in fig. 7 may be mentioned.

The first wall surface 21 may be connected to the first discharge groove 17, and the second wall surface 23 may be separated from the first discharge groove 17. In this case, chips flowing through the first sipe 15 easily advance toward the first discharge groove 17. In addition, as will be described later, when the main body 3 has the second sipe 25, chips flowing through the first sipe 15 are likely to advance to the second sipe 25 in addition to the first discharge groove 17.

The second wall surface 23 may have a portion where the width W becomes smaller as approaching the second end 3 b. The entire second wall surface 23 may be configured such that the width W becomes smaller as it approaches the second end 3 b. In the case where the width W at the portion of the second wall surface 23 located near the first end 3a, in other words, near the cutting edge is relatively large, the chip can be stably bent at the second wall surface 23.

Further, in the case where the second wall surface 23 has a portion whose width W becomes smaller as approaching the second end 3b, the width W becomes smaller at a portion of the second wall surface 23 located in the vicinity of the second end 3 b. Therefore, the chips can be easily passed over the second wall surface 23 while being stably bent. The width W may be the width of the rod-shaped body 3 in the radial direction. As shown in fig. 9, the width W may be evaluated in a cross section perpendicular to the rotation axis R1.

The width W may continuously decrease at a portion of the second wall surface 23 where the width W decreases as it approaches the second end 3 b. When the width W is continuously reduced and the edge does not exist at the upper end of the second wall surface 23, the abrasion of the second wall surface 23 is less likely to develop, and the second wall surface 23 is less likely to be chipped. Therefore, the end mill 1 can be used stably for a long period of time.

The first pocket 15 may be connected with the second flank 13. In this case, chips generated by the chisel edge 5 and the first cutting edge 7 can flow into the first sipe 15 stably. Therefore, chips are less likely to be jammed in the vicinity of the chisel edge 5 and the first cutting edge 7.

At this time, the ridge line L1 where the second flank surface 13 intersects with the second wall surface 23 may have a portion inclined rearward in the rotation direction R2 as it is away from the rotation axis R1 when viewed from the front end, that is, when viewed from the front end of the first end 3a. In this case, the amount of the first sipe 15 located in front of the direction in which the cutting load is applied to the second cutting edge 9 can be reduced, and the wall thickness of the portion of the main body 3 located in front of the direction in which the cutting load is applied to the second cutting edge 9 can be ensured to be thick. Therefore, durability against the cutting load applied to the second cutting edge 9 is high.

The body 3 may also have a second sipe 25 in addition to the first sipe 15. As an example, which is not limited to the one shown in fig. 7, the second sipe 25 may be connected to the first sipe 15 in front of the rotation direction R2. Here, the first wall surface 21 may be connected to the second sipe 25 at a position closer to the second end 3b than the end of the second wall surface 23 on the second end 3b side.

In this case, the chips flowing on the first wall surface 21 easily advance toward the second sipe 25 located forward of the first sipe 15 in the rotation direction R2 in the region of the first wall surface 21 located closer to the second end 3b than the second wall surface 23.

The first sipe 15 and the second sipe 25 may be portions called a center groove, respectively. For example, the first sipe 15 may be positioned as a first center groove, and the second sipe 25 may be positioned as a second center groove.

The second sipe 25 may be a V-groove shape, and may also have a second bottom 27, a third wall 29, and a fourth wall 31. As an example, which is not limited to the one shown in fig. 7, the third wall surface 29 may be located relatively rearward of the rotation direction R2, the fourth wall surface 31 may be located relatively forward of the rotation direction R2, and the second bottom 27 may be located between the third wall surface 29 and the fourth wall surface 31.

Here, the first wall surface 21 of the first sipe 15 may extend to a position closer to the second end 3b than the second wall surface 23, and the third wall surface 29 and the fourth wall surface 31 of the second sipe 25 may extend to a position at the same distance from the second end 3 b. Since the second sipe 25 is located forward of the first sipe 15 in the rotation direction R2, a space for chip flow is large, and chips are less likely to be clogged in the second sipe 25 than in the first sipe 15. Therefore, even if the fourth wall surface 31 extends toward the second end 3b to the same extent as the third wall surface 29, the chip is less likely to be clogged, and the chip can be stably bent by the fourth wall surface 31.

The same degree means that the distance from the second end 3b to the third wall surface 29 is about 95 to 105% with respect to the distance from the second end 3b to the fourth wall surface 31.

The second cutting edge 9 has an inner end 9a connected to the chisel edge 5. In the front end view, a virtual straight line that is orthogonal to the tangent of the second cutting edge 9 at the inner end portion 9a and that passes through the inner end portion 9a is set as a reference line L3. At this time, the first sipe 15 may be located rearward of the reference line L3 in the rotational direction R2, and the second sipe 25 may intersect the reference line L3.

When the first sipe 15 is located rearward of the reference line L3 in the rotation direction R2, the thickness of the main body 3 can be ensured to be thick at a portion located forward of the direction in which the cutting load is applied to the second cutting edge 9 and at a portion located in the vicinity of the second cutting edge 9. Therefore, durability against the cutting load applied to the second cutting edge 9 is high.

Even when the second sipe 25 intersects the reference line L3, that is, when the second sipe 25 is located locally in front of the direction in which the cutting load is applied to the second cutting edge 9, the influence on the durability of the second cutting edge 9 is small. This is because the second sipe 25 is located forward of the first sipe 15 in the rotation direction R2. On the other hand, when the second sipe 25 is located locally in front of the direction in which the cutting load is applied to the second cutting edge 9, the space in which the chips generated in the first cutting edge 7 flow is ensured to be large. Therefore, the chip discharge performance is higher.

The angle at which the first sipe 15 intersects the second sipe 25 may also become smaller as it approaches the second end 3 b. Specifically, in a cross section orthogonal to the rotation axis X1, an angle at which the first sipe 15 and the second sipe 25 intersect is set to an angle θ. The angle θ may also become larger as it approaches the second end 3 b.

In the case where the angle θ at which the first sipe 15 intersects the second sipe 25 at the portion located near the first end 3a, of the ridge line L2 at which the first sipe 15 intersects the second sipe 25, is relatively small, the chip can be stably bent in the first sipe 15. In the case where the angle θ at which the first sipe 15 intersects the second sipe 25 at the portion located near the second end 3b is relatively large, of the ridge line L2 at which the first sipe 15 intersects the second sipe 25, the chips can be easily made to pass over the second wall surface 23.

Therefore, in the case where the angle θ at which the first sipe 15 intersects with the second sipe 25 becomes smaller as approaching the second end 3b, the chip can be stably bent and easily made to flow toward the second sipe 25.

The first sipe 15 may have a portion smoothly connected to the second sipe 25 on the second end 3b side. As an example, which is not limited, shown in fig. 11 and 12, of the ridge line L2 where the first sipe 15 and the second sipe 25 intersect, the angle θ of the portion located near the second end 3b is 180 °, that is, the first sipe 15 may have a portion smoothly connected to the second sipe 25. In this case, the chips can be more easily flowed into the second sipe 25.

The main body 3 may have a third sipe 33, a fourth sipe 35, and a second discharge groove 37.

The third pocket 33 may be connected to the second cutting edge 9 in front of the rotation direction R2. That is, the second cutting edge 9 may be located at a position where the second relief surface 13 intersects the third pocket 33. The third pocket 33 may have a function of improving the strength of the second cutting edge 9.

The relationship of the third sipe 33 with respect to the second cutting edge 9 may be the same as the relationship of the first sipe 15 with respect to the first cutting edge 7. That is, the third sipe 33 may have the third bottom portion 39 as a surface corresponding to the first bottom portion 19 in the first sipe 15, the fifth wall surface 41 as a surface corresponding to the first wall surface 21 in the first sipe 15, and the sixth wall surface 43 as a surface corresponding to the second wall surface 23 in the first sipe 15.

As an example, which is not limited to the one shown in fig. 13, the fourth sipe 35 may be connected to the third sipe 33 in front of the rotation direction R2. The relationship of the fourth sipe 35 with respect to the second cutting edge 9 may be the same as the relationship of the second sipe 25 with respect to the first cutting edge 7. That is, the fourth sipe 35 may have the fourth bottom portion 45 as a surface corresponding to the second bottom portion 27 in the second sipe 25, the seventh wall surface 47 as a surface corresponding to the third wall surface 29 in the second sipe 25, and the eighth wall surface 49 as a surface corresponding to the fourth wall surface 31 in the second sipe 25. Here, the sixth wall surface 43 may be connected to the fourth pocket 35 at a position closer to the second end 3b than the end on the second end 3b side of the sixth wall surface 43.

Examples of the material of the body 3 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, taC is hard particles and Co is the binder phase. The cermet may be a sintered composite material obtained by compounding a metal and a ceramic component. Specifically, as the cermet, a titanium compound containing titanium carbide (TiC) or titanium nitride (TiN) as a main component is exemplified.

The surface of the body 3 may be coated with a film by a Chemical Vapor Deposition (CVD) method or a Physical Vapor Deposition (PVD) method. Examples of the composition of the coating film include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al ₂O₃). The thickness of the coating film may be set to, for example, 0.3 μm to 20 μm. The preferable range varies depending on the composition of the coating film.

While the end mill 1 of the embodiments has been described above, the present invention is not limited to this, and any method may be adopted without departing from the gist of the present invention.

< Method for producing machined product (machined product) >)

Next, a method for manufacturing the machined product 101 according to the non-limiting embodiment will be described in detail by taking as an example a case where the end mill 1 according to the non-limiting embodiment is used. Hereinafter, description will be given with reference to fig. 14 to 16. Fig. 14 to 16 illustrate a process of forming a hole in the workpiece 103 as an example of a method of manufacturing the machined product 101. In fig. 14 to 16, the workpiece 101 and the workpiece 103 are seen in cross section to facilitate visual understanding.

The method for producing the machined product 101 according to the non-limiting embodiment may include the following steps (1) to (3).

(1) The end mill 1 may be rotated in the direction of arrow R2 about the rotation axis R1, and the end mill 1 may be moved closer to the workpiece 103 in the Y1 direction (see fig. 14).

This step can be performed by, for example, fixing the workpiece 103 to a table of a machine tool to which the end mill 1 is attached, and bringing the end mill 1 closer to each other in a rotated state. In this step, the workpiece 103 may be relatively close to the end mill 1, or the workpiece 103 may be close to the end mill 1.

(2) The end mill 1 is brought into further proximity to the workpiece 103, and the rotating end mill 1 is brought into contact with a desired position on the surface of the workpiece 103, whereby the workpiece 103 is cut (see fig. 15).

In this step, the chisel edge, the first cutting edge, and the second cutting edge may be brought into contact with a desired position on the surface of the workpiece 103.

(3) The end mill 1 can be separated from the workpiece 103 in the Y2 direction (see fig. 16).

In this step, as in the step (1), the end mill 1 may be separated from the workpiece 103, for example, by separating the workpiece 103 from the end mill 1. The cutting process may be, for example, a hole process, a groove process, a milling process, or the like, which do not penetrate, in addition to the hole process shown in fig. 16.

Through the above steps, excellent workability can be exhibited.

In the case of performing the cutting process of the workpiece 103 shown above a plurality of times, for example, in the case of performing a plurality of cutting processes on 1 workpiece 103, the step of bringing the end mill 1 into contact with different portions of the workpiece 103 may be repeated while maintaining the state in which the end mill 1 is rotated.

Description of the reference numerals

End mill

Main body

First end @

Second end

5. Chisel edge

First cutting edge

Second cutting edge

Inner end portion

First flank surface

Second flank surface

First sipe

First discharge tank

First bottom

First wall surface

Second wall surface

Second sipe

Second bottom

Third wall surface

Fourth wall surface

Third sipe

Fourth sipe

Second discharge tank

Third bottom

Fifth wall surface

Sixth wall surface

45. Fourth bottom

Seventh wall surface

49. Eighth wall surface

Cutting product

Cut piece

R1. rotation axis

R2. direction of rotation

W. width

L1. edge line (second flank and second wall surface)

L2. edge line (first and second sipe)

L3. datum line

Angle (angle at which the first sipe intersects the second sipe).

Claims

1. An end mill, wherein,

The end mill has a body extending along an axis of rotation from a first end to a second end,

The main body has:

A chisel edge at the first end;

A first cutting edge and a second cutting edge extending from the chisel edge toward the outer periphery, respectively;

a first flank surface connected to the first cutting edge at a rear side of the rotation direction of the rotation shaft;

A second flank surface connected to the second cutting edge at a rear side of the rotation direction of the rotation shaft;

a first pocket connected to the first cutting edge in front of the rotation direction; and

A discharge slot located closer to the second end than the first sipe,

The first sipe has:

A bottom;

A first wall surface located between the bottom and the first cutting edge and connected to the discharge groove; and

A second wall surface which is located forward of the rotation direction with respect to the bottom portion and is separated from the discharge groove,

The first wall extends to a position closer to the second end than the second wall.

2. An end mill, wherein,

The main body has:

A chisel edge at the first end;

A discharge slot located closer to the second end than the first sipe,

The first sipe has:

A bottom;

a first wall surface located between the bottom and the first cutting edge; and

A second wall surface located forward of the rotation direction with respect to the bottom portion,

The first wall extends to a position closer to the second end than the second wall,

When the first end is viewed from the front, a ridge line intersecting the second flank surface and the second wall surface is inclined rearward in the rotation direction as being away from the rotation axis.

3. An end mill, wherein,

The main body has:

A chisel edge at the first end;

a first pocket connected to the first cutting edge in front of the rotation direction;

a second sipe connected to the first sipe in front of the rotation direction; and

A discharge slot located closer to the second end than the first sipe,

The first sipe has:

A bottom;

a first wall surface located between the bottom and the first cutting edge; and

The first wall surface is connected to the second pocket at a position closer to the second end than an end portion of the second wall surface on the second end side.

4. An end mill, wherein,

The main body has:

A chisel edge at the first end;

A discharge slot located closer to the second end than the first sipe,

The second cutting edge has an inner end connected to the chisel edge,

When the first end is viewed in front elevation,

An imaginary straight line orthogonal to a tangent of the second cutting edge at the inner end portion and passing through the inner end portion is a reference line,

The first sipe is located rearward of the reference line in the rotational direction, and has:

A bottom;

a first wall surface located between the bottom and the first cutting edge; and

The second sipe intersects the reference line.

5. An end mill, wherein,

The main body has:

A chisel edge at the first end;

A discharge slot located closer to the second end than the first sipe,

The first sipe has:

A bottom;

a first wall surface located between the bottom and the first cutting edge; and

The angle at which the first sipe intersects the second sipe becomes larger as approaching the second end.

6. The end mill according to claim 5, wherein,

The first sipe has a portion smoothly connected to the second sipe at the second end side.

7. The end mill according to any one of claims 1 to 6, wherein,

The width of the second wall surface becomes smaller as approaching the second end.

8. A method for manufacturing a machined product, wherein,

The method for manufacturing the machined product comprises the following steps:

a step of rotating the end mill according to any one of claims 1 to 7;

A step of bringing the rotating end mill into contact with a workpiece; and

And a step of separating the end mill from the workpiece.