JP7344321B2 - Manufacturing method for rotating tools and cutting products - Google Patents

Description

Cross-reference of related applications

This application claims priority to Japanese Patent Application No. 2020-013389 filed on January 30, 2020, and the entire disclosure of this earlier application is hereby incorporated by reference.

TECHNICAL FIELD The present disclosure generally relates to a rotary tool used for milling a workpiece. Rotary tools may include, for example, drills and end mills.

A rotary tool can be mentioned as a cutting tool used when turning a work material. The drill described in Japanese Patent Publication No. 2019-501787 (Patent Document 1) is an example of a rotating tool. The drill described in Patent Document 1 has a groove adjacent to the cutting blade. The groove has a function as a chip breaker.

In Patent Document 1, of the portions of the cutting blade along the groove, the portion located near the rotation axis has a lower rotational speed than the portion located on the outer peripheral side. Therefore, there is a risk that the chips generated in the portion located on the outer circumferential side described above may clog the bottom of the groove.

A rotary tool according to one non-limiting aspect of the present disclosure has a body that extends from a first end to a second end along an axis of rotation and is rotatable about the axis of rotation. The main body has a cutting blade located on the first end side, a recess connected to the cutting blade, a groove extending from the recess toward the second end, and an outer peripheral surface. The cutting edge includes a first blade and a second blade located closer to the outer circumferential surface than the first blade. The recess has a concavely curved bottom surface, a first plane located closer to the rotation axis than the bottom surface, and a second plane located closer to the outer circumferential surface than the bottom surface. The first plane is connected to the first blade, and the second plane is connected to the second blade.

1 is a perspective view of a rotary tool (drill) according to a non-limiting embodiment of the present disclosure; FIG. FIG. 2 is a plan view of the rotary tool shown in FIG. 1 viewed from the first end side. FIG. 2 is a plan view of the rotary tool shown in FIG. 1 viewed from the first end side. FIG. 3 is a side view of the rotary tool shown in FIG. 2 when viewed from direction A1. FIG. 3 is a side view of the rotary tool shown in FIG. 2 when viewed from direction A2. FIG. 2 is an enlarged perspective view of the first end side of the rotary tool shown in FIG. 1. FIG. FIG. 2 is an enlarged plan view of the first end side of the rotary tool shown in FIG. 1; FIG. 2 is an enlarged plan view of the first end side of the rotary tool shown in FIG. 1; FIG. 2 is an enlarged plan view of the first end side of the rotary tool shown in FIG. 1; 10 is an enlarged view of the X section of the rotary tool shown in FIG. 9. FIG. 10 is an enlarged view of the XI cross section of the rotary tool shown in FIG. 9. FIG. 10 is an enlarged view of the XII cross section of the rotary tool shown in FIG. 9. FIG. 10 is an enlarged view of the XIII cross section of the rotary tool shown in FIG. 9. FIG. FIG. 2 is an enlarged plan view of the first end side of the rotary tool shown in FIG. 1; 15 is an enlarged view of the XV cross section of the rotary tool shown in FIG. 14. FIG. 15 is an enlarged view of the XVI cross section of the rotary tool shown in FIG. 14. FIG. 15 is an enlarged view of the XVII cross section of the rotary tool shown in FIG. 14. FIG. 15 is an enlarged view of the XVIII cross section of the rotary tool shown in FIG. 14. FIG. FIG. 2 is a schematic diagram illustrating one step in a method for manufacturing a cut workpiece according to a non-limiting embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating one step in a method for manufacturing a cut workpiece according to a non-limiting embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating one step in a method for manufacturing a cut workpiece according to a non-limiting embodiment of the present disclosure.

<Rotary tools>
Hereinafter, a rotary tool 1 according to a non-limiting embodiment of the present disclosure will be described in detail using the drawings. However, in each figure referred to below, only main members necessary for explaining the embodiment are shown in a simplified manner for convenience of explanation. Therefore, the rotary tool 1 may include any constituent members not shown in the respective figures referred to. Furthermore, the dimensions of the members in each figure do not faithfully represent the dimensions of the actual constituent members or the dimensional ratios of each member.

1 to 18, a drill is shown as a non-limiting example of the rotary tool 1. Note that the rotary tool 1 is not limited to a drill, and may be, for example, an end mill.

The rotary tool 1 may have a main body 3, as in a non-limiting example shown in FIG. The main body 3 may extend from the first end 3a to the second end 3b along the rotation axis O1. More specifically, the main body 3 may have a rod shape extending from the first end 3a to the second end 3b along the rotation axis O1. Generally, the first end 3a is called the "tip" and the second end 3b is called the "rear end." Further, the main body 3 may be rotatable around the rotation axis O1. Note that the arrow Y1 in FIG. 1 and the like indicates the rotation direction of the rotation axis O1.

The main body 3 may have a shank portion 5 and a cutting portion 7. The shank portion 5 may be a portion that can be gripped by a rotating spindle of a machine tool. The shank portion 5 may be designed according to the shape of the spindle in the machine tool.

The cutting part 7 may be located on the first end 3a side with respect to the shank part 5. The cutting part 7 is a part that can come into contact with the workpiece and can play a major role in cutting the workpiece.

The outer diameter D of the cutting portion 7 is not limited to a specific value. For example, the maximum value of the outer diameter D may be set to 4 to 50 mm. Further, the length L of the cutting portion 7 in the direction along the rotation axis O1 may be set to L=1.5D to 12D.

As in a non-limiting example shown in FIG. 6, the main body 3 may have a cutting edge 9, a recess 11, a groove 13, and an outer peripheral surface 15. The cutting edge 9 may be located on the first end 3a side. The recess 11 may be connected to the cutting edge 9. The groove 13 may extend from the recess 11 toward the second end 3b. Note that the cutting edge 9, the recess 11, the groove 13, and the outer peripheral surface 15 may be located in the cutting part 7.

The cutting blade 9 can be used to cut a workpiece during cutting. The cutting blade 9 may have a first blade 17 and a second blade 19. The second blade 19 may be located closer to the outer peripheral surface 15 than the first blade 17.

The first blade 17 is also called the main cutting edge. As in a non-limiting example shown in FIG. 2, the first blade 17 may have a linear shape when viewed from the front toward the first end 3a. Further, the first blade 17 may be separated from the rotation axis O1.

The number of first blades 17 may be one or more. When the number of first blades 17 is plural, the number may be 2 to 5. These points also apply to the second blade 19. Note that the rotary tool 1 in a non-limiting example shown in FIG. 1 is a so-called two-blade drill.

When the number of first blades 17 is plural, the plurality of first blades 17 may be positioned so as to be rotationally symmetrical with respect to the rotation axis O1 when viewed from the front toward the first end 3a. . Specifically, as in the non-limiting example shown in FIG. 2, when the number of first blades 17 is two, two first blades 17 rotate when viewed from the front toward the first end 3a. It may be located so as to have rotational symmetry of 180 degrees with respect to the axis O1. In this case, the rotary tool 1 has high straightness when cutting the workpiece. These points also apply to the second blade 19.

The second blade 19 is also called the main cutting edge. The second blade 19 may have a linear shape when viewed from the front toward the first end 3a. The length of the second blade 19 may be the same as the length of the first blade 17, or may be different. As in a non-limiting example shown in FIG. 2, the length of the second blade 19 may be longer than the length of the first blade 17. Note that the first blade 17 and the second blade 19 may be connected to each other, or another blade may be located between them.

The groove 13 can be used to discharge chips generated by the cutting edge 9 to the outside. The groove 13 may extend parallel to the rotation axis O1, or may extend spirally around the rotation axis O1. Further, from the viewpoint of smoothly discharging chips to the outside, the groove 13 may have a concave curved shape in a cross section perpendicular to the rotation axis O1. The number of grooves 13 may be one or more. The number of grooves 13 may be the same as the number of cutting edges 9.

Note that the groove 13 and the recess 11 may be connected to each other, or another portion may be located between them. When the grooves 13 and the recesses 11 are connected to each other, as in the non-limiting example shown in FIG. 6, the direction in which chips generated by the cutting edge 9 are discharged is stabilized.

The depth of the groove 13 is not limited to a specific value. For example, the depth of the groove 13 may be set to 10 to 40% of the outer diameter of the main body 3 (cutting portion 7). The depth of the groove 13 may be a value obtained by subtracting the distance between the bottom of the groove 13 and the rotation axis O1 from the radius of the main body 3 (cutting portion 7) in a cross section perpendicular to the rotation axis O1. The bottom may refer to the portion of the groove 13 closest to the rotation axis O1.

The recess 11 can be used to curl chips generated by the cutting edge 9. Furthermore, the recess 11 can be used to control the direction in which chips generated by the cutting edge 9 flow. Note that the recess 11 may be depressed relative to the groove 13.

The recess 11 may have a bottom surface 21, a first plane 23, and a second plane 25, as in a non-limiting example shown in FIG. The bottom surface 21 may have a concave curved shape, as in a non-limiting example shown in FIG. The first plane 23 may be located closer to the rotation axis O1 than the bottom surface 21. The second plane 25 may be located closer to the outer peripheral surface 15 than the bottom surface 21. Note that the bottom surface 21 only needs to have a generally concave curved shape when visually observed, and does not strictly need to have a concave curved shape as a whole. Similarly, the first plane 23 and the second plane 25 only need to have an approximately planar shape when visually observed, and do not need to have a strictly planar shape as a whole.

Here, the first plane 23 may be connected to the first blade 17, as in a non-limiting example shown in FIG. Further, the second plane 25 may be connected to the second blade 19. In these cases, the direction in which chips are generated tends to change, and the fragmentation of chips is likely to be promoted. Therefore, the chip discharge performance is high.

Note that the bottom surface 21 and the first plane 23 may be connected to each other, or another surface may be located between them. This also applies to the bottom surface 21 and the second plane 25. In one non-limiting example shown in FIG. 16, the bottom surface 21 and the first plane 23 are connected to each other, and the bottom surface 21 and the second plane 25 are connected to each other.

As a non-limiting example shown in FIG. 7, the first plane 23 may have a first portion 27 and a second portion 29. The first portion 27 may have a constant width W1 in the direction along the rotation axis O1. The second portion 29 may be located closer to the outer peripheral surface 15 than the first portion 27 . Further, the width W2 of the second portion 29 in the direction along the rotation axis O1 may become smaller as the distance from the rotation axis O1 increases. In these cases, the width of W2 tends to become smaller on the outer circumferential side where the amount of cutting is greater. Therefore, clogging of chips is suppressed, and chip discharge performance is high.

Note that "constant" only needs to be approximately constant, and does not need to be constant in a strict sense. Constant may include a range of ±1 mm. The first portion 27 and the second portion 29 may be connected to each other, or another portion may be located between them. In one non-limiting example shown in FIG. 7, first portion 27 and second portion 29 are connected to each other. Further, the area of the second portion 29 may be smaller than the area of the first portion 27.

The first plane 23 may have a linear edge 23a located on the second end 3b side. The edge 23a may extend away from the cutting blade 9 (first blade 17) as it approaches the outer circumferential surface 15.

As in a non-limiting example shown in FIG. 6, the cutting blade 9 may further include a third blade 31. The third blade 31 may be connected to the outer peripheral surface 15. Further, as in a non-limiting example shown in FIG. 8, the inclination angle θ3 of the third blade 31 with respect to the rotation axis O1 may be smaller than the inclination angle θ2 of the second blade 19 with respect to the rotation axis O1 when viewed from the side. . As in a non-limiting example shown in FIG. 7, the end 31a of the third blade 31 that is closer to the rotation axis O1 is located closer to the rotation axis O1 than the end 29a of the second portion 29 that is closer to the rotation axis O1. Good too.

When the inclination angle θ3 is smaller than the inclination angle θ2, the thickness of chips produced by the third blade 31 tends to be thinner than the thickness of chips produced by the second blade 19. Therefore, the direction in which chips generated by the third blade 31 flow tends to become unstable. When the end 31a of the third blade 31 that is closer to the rotation axis O1 is located closer to the rotation axis O1 than the end 29a of the second portion 29 that is closer to the rotation axis O1, chips generated by the third blade 31 are , can easily contact the first portion 27. The width W1 of the entire first portion 27 in the direction along the rotation axis O1 is wider than the width W2 of the entire second portion 29 in the direction along the rotation axis O1. That is, when chips that are generated by the third blade 31 and tend to flow in an unstable direction come into contact with the first portion 27 having a wide width W1 as a whole, the chips can be stably curved. As a result, chips are less likely to become clogged.

The side view in the above paragraph (the side view when evaluating the inclination angle of the cutting edge 9) refers to the side view when viewed from a direction perpendicular to the rotation axis O1 and perpendicular to the first straight line L1 in the non-limiting example shown in FIG. It can also mean when something happens. The first straight line L1 may be a virtual straight line connecting the end 9a of the cutting blade 9 close to the outer peripheral surface 15 and the rotation axis O1 when viewed from the front toward the first end 3a. FIG. 8 is a side view from a direction perpendicular to the first straight line L1 and perpendicular to the rotation axis O1. Note that, as in a non-limiting example shown in FIG. 8, when evaluating the inclination angle of the cutting blade 9, a line L2 parallel to the rotation axis O1 may be used as a reference.

The inclination angle θ2 of the second blade 19 and the inclination angle θ3 of the third blade 31 are not limited to specific values. For example, the inclination angle θ2 may be set to 10 to 25 degrees. Further, the inclination angle θ3 may be set to 15 to 30°. The inclination angle θ1 of the first blade 17 is also not limited to a specific value. For example, the inclination angle θ1 may be set to 15 to 35 degrees.

The second blade 19 and the third blade 31 may be connected to each other, or another blade may be located between them. In one non-limiting example shown in FIG. 7, the second blade 19 and the third blade 31 are connected to each other. Further, the length of the third blade 31 may be shorter than the length of the second blade 19. The third blade 31 may have a linear shape or a curved shape when viewed from the side. As in a non-limiting example shown in FIG. 7, the third blade 31 may have a convex curved shape when viewed from the side.

The second plane 25 may be connected to the third blade 31. In this case, the chips generated by the third blade 31 are likely to be pulled by the chips generated by the second blade 19. Therefore, the direction in which the thin chips generated by the third blade 31 flow can be stabilized.

The second plane 25 may have a third portion 33 . The width W3 of the third portion 33 in the direction along the rotation axis O1 may increase as the distance from the rotation axis O1 increases. In this case, the chips generated on the outside are less likely to cause resistance within the second plane 25, and the effect of dividing the chips according to the cutting amount of the front blade (cutting blade 9) can be stably obtained.

As in a non-limiting example shown in FIGS. 11 and 12, the bottom surface 21 may have a fourth portion 35. The fourth portion 35 may have a constant width W4 in the direction along the rotation axis O1. In this case, the resistance received by the first plane 23 increases on the outer circumferential side where the curl diameter of the chips tends to increase, so that division of the chips can be promoted.

Note that the radius of curvature in the fourth portion 35 may be constant. Further, the bottom surface 21 may extend away from the cutting edge 9 as it approaches the outer circumferential surface 15.

As in a non-limiting example shown in FIG. 3, the radial rake β1 of the first blade 17 may be smaller than the radial rake β2 of the second blade 19. In this case, chips generated by the first blade 17 and chips generated by the second blade 19 tend to flow away from each other. Therefore, separation of chips can be promoted. The radial rake β1 of the first blade 17 and the radial rake β2 of the second blade 19 are not limited to specific values. For example, the radial rake β1 may be set to −60° to −20°. Further, the radial rake β2 may be set to -15 to 15 degrees.

The radial rake may refer to the inclination angle of the rotation axis O1 with respect to the radial direction when viewed from the front toward the first end 3a. For example, as in a non-limiting example shown in FIG. 3, the radial rake β1 at the point 17A on the first blade 17 is defined by a virtual straight line passing through the rotation axis O1 and the point 17A, and a tangent to the first blade 17 at the point 17A. It may also mean an intersecting angle. Furthermore, the radial rake β2 at point 19A on second blade 19 may mean the angle at which a virtual straight line passing through rotation axis O1 and point 19A intersects with a tangent to second blade 19 at point 19A.

As a non-limiting example shown in FIGS. 10-13, the axial rake α1 of the first blade 17 may be smaller than the axial rake α2 of the second blade 19. In this case, the tool rigidity increases at locations where the cutting speed is low, resulting in a tool that is resistant to chipping. Note that the axial rake α1 of the first blade 17 and the axial rake α2 of the second blade 19 are not limited to specific values. For example, the axial rake α1 of the first blade 17 may be set to 3 to 20 degrees. The axial rake α2 of the second blade 19 may be set to 15 to 45 degrees.

The recess 11 may extend toward the rear in the rotation direction Y1 of the rotation axis O1 as it approaches the outer peripheral surface 15. In this case, the strength of the outer peripheral end of the cutting blade 9 can be improved.

As in a non-limiting example shown in FIG. 2, the cutting blade 9 may further include a fourth blade 37 located between the first blade 17 and the second blade 19. The fourth blade 37 may have a concave curved shape. The fourth blade 37 may be connected to the first blade 17 and the second blade 19. The bottom surface 21 may be connected to the fourth blade 37.

Examples of the material of the main body 3 include cemented carbide and cermet. Compositions of the cemented carbide may include, for example, WC-Co, WC-TiC-Co and WC-TiC-TaC-Co. Here, WC, TiC, and TaC may be hard particles, and Co may be a binder phase.

Further, the cermet may be a sintered composite material in which a metal is combined with a ceramic component. Specifically, the cermet may include a titanium compound containing titanium carbide (TiC) or titanium nitride (TiN) as a main component. However, the above-mentioned materials are just examples, and the main body 3 is not limited to these materials.

The surface of the body 3 may 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 coating include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al ₂ O ₃ ).

<Method for manufacturing cut workpieces>
Next, a method for manufacturing the cut workpiece 101 according to a non-limiting embodiment will be described using the drawings.

The cut workpiece 101 may be produced by cutting a workpiece 103. A method for manufacturing the cut workpiece 101 in a non-limiting embodiment may include the following steps (1) to (4).

(1) Step of arranging the rotary tool 1 above the prepared workpiece 103 (see FIG. 19).
(2) A process of rotating the rotary tool 1 in the direction of the arrow Y1 around the rotation axis O1 and moving the rotary tool 1 closer to the workpiece 103 in the Y2 direction (see FIGS. 19 and 20).

In the steps (1) and (2), for example, the workpiece 103 is fixed on the table of a machine tool to which the rotary tool 1 is attached, and the rotary tool 1 is brought close to the workpiece 103 while being rotated. You may do so depending on the situation. In addition, in the step (2), the workpiece 103 and the rotary tool 1 may be brought relatively close to each other; for example, the workpiece 103 may be brought close to the rotary tool 1.

(3) By bringing the rotary tool 1 closer to the workpiece 103, the rotating rotary tool 1 is brought into contact with a desired position on the surface of the workpiece 103, and the machined hole 105 is formed in the workpiece 103. Forming step (see FIG. 20).

In the step (3), the cutting process may be performed such that at least a part of the cutting part 7 in the main body 3 is located in the machined hole 105. At this time, the shank portion 5 of the main body 3 may be set to be located outside the machined hole 105. Further, from the viewpoint of obtaining a good finished surface, a part of the cutting portion 7 on the second end 3b side may be set to be located outside the machined hole 105. It is possible to make the above part function as a margin area for discharging chips, and it is possible to achieve excellent chip discharging performance through this region.

(4) Step of separating the rotary tool 1 from the workpiece 103 in the Y3 direction (see FIG. 21).
In the step (4), as in the step (2) above, the workpiece 103 and the rotary tool 1 only need to be relatively separated. For example, the workpiece 103 may be separated from the rotary tool 1. good.

When the above steps are carried out, it is possible to exhibit excellent workability. Specifically, when using the rotary tool 1 in the method for manufacturing the cut workpiece 101 according to the non-limiting embodiment, since the rotary tool 1 has a high chip evacuation property, a cutter having a machined hole 105 with high accuracy It becomes possible to obtain the workpiece 101.

Note that when cutting the workpiece 103 as described above is performed multiple times, for example, when forming a plurality of machined holes 105 in one workpiece 103, the rotary tool 1 The process of bringing the cutting edge 9 of the rotary tool 1 into contact with different locations on the workpiece 103 while maintaining the rotated state may be repeated.

Examples of the material of the work material 103 include aluminum, carbon steel, alloy steel, stainless steel, cast iron, and nonferrous metals.

1...Rotary tool (drill)
3... Main body 3a... First end (tip)
3b...Second end (rear end)
5... Shank part 7... Cutting part 9... Cutting edge 9a... End part 11... Recessed part 13... Groove 15... Outer peripheral surface 17... First blade 19... Second blade 21...bottom surface 23...first plane 23a...edge 25...second plane 27...first portion 29...second portion 29a...end 31... Third blade 31a... End 33... Third part 35... Fourth part 37... Fourth blade 101... Cutting workpiece 103... Work material 105... Machining hole O1 ... Rotation axis Y1 ... Rotation direction

Claims (10)

having a main body extending from a first end to a second end along a rotation axis and rotatable around the rotation axis;
The main body is
a cutting blade located on the first end side;
a recess connected to the cutting edge;
a groove extending from the recess toward the second end;
having an outer peripheral surface;
The cutting edge is
The first blade and
a second blade located closer to the outer peripheral surface than the first blade;
The recess is
A concave curved bottom surface,
a first plane located closer to the rotation axis than the bottom surface;
a second plane located closer to the outer peripheral surface than the bottom surface;
the first plane is connected to the first blade,
the second plane is connected to the second blade ;
The first plane is
a first portion having a constant width in the direction along the rotation axis;
a second portion that is located closer to the outer circumferential surface than the first portion and whose width in the direction along the rotation axis becomes smaller as the distance from the rotation axis increases. having a main body extending from a first end to a second end along a rotation axis and rotatable around the rotation axis;
The main body is
a cutting blade located on the first end side;
a recess connected to the cutting edge;
a groove extending from the recess toward the second end;
having an outer peripheral surface;
The cutting edge is
The first blade and
a second blade located closer to the outer peripheral surface than the first blade;
The recess is
A concave curved bottom surface,
a first plane located closer to the rotation axis than the bottom surface;
a second plane located closer to the outer peripheral surface than the bottom surface;
the first plane is connected to the first blade,
the second plane is connected to the second blade ;
The second plane has a third portion that increases in width in a direction along the rotation axis as the distance from the rotation axis increases . The rotary tool according to claim 2 , wherein the bottom surface has a fourth portion having a constant width in a direction along the rotation axis. having a main body extending from a first end to a second end along a rotation axis and rotatable around the rotation axis;
The main body is
a cutting blade located on the first end side;
a recess connected to the cutting edge;
a groove extending from the recess toward the second end;
having an outer peripheral surface;
The cutting edge is
The first blade and
a second blade located closer to the outer peripheral surface than the first blade;
The recess is
A concave curved bottom surface,
a first plane located closer to the rotation axis than the bottom surface;
a second plane located closer to the outer peripheral surface than the bottom surface;
the first plane is connected to the first blade,
the second plane is connected to the second blade ;
The rotary tool , wherein the bottom surface has a fourth portion having a constant width in a direction along the rotation axis . The first plane is
a first portion having a constant width in the direction along the rotation axis;
and a second portion located closer to the outer circumferential surface than the first portion and whose width in the direction along the rotation axis decreases as the distance from the rotation axis increases. The rotary tool described in item 1 . The cutting edge further includes a third blade connected to the outer peripheral surface,
When viewed from the side, the angle of inclination of the third blade with respect to the axis of rotation is smaller than the angle of inclination of the second blade with respect to the axis of rotation,
The rotary tool according to claim 1 or 5 , wherein an end of the third blade closer to the rotation axis is located closer to the rotation axis than an end of the second portion closer to the rotation axis. The rotary tool according to claim 6 , wherein the second plane is connected to the third blade. The rotary tool according to any one of claims 1 to 7 , wherein the radial rake of the first blade is smaller than the radial rake of the second blade. The rotary tool according to any one of claims 1 to 8, wherein the recess extends toward the rear in the rotational direction of the rotary shaft as it approaches the outer peripheral surface. a step of rotating the rotary tool according to any one of claims 1 to 9;
a step of bringing the rotating rotary tool into contact with a workpiece;
A method for manufacturing a cut workpiece, comprising the step of separating the rotary tool from the workpiece.

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