Rotary tool and method for manufacturing machined product

Abstract

A rotating tool according to one non-limiting aspect of the present disclosure comprises: a holder that has a pocket which is positioned on a tip end side and extends along a rotation shaft and from the tip end to a rear end; a cutting insert that is positioned in the pocket; and a screw that fixes the cutting insert to the holder. The pocket has seating surface which faces forward in the rotation direction of the rotation shaft, and a screw hole which extends rearward in the rotation direction from the seating surface and in which the screw is fixed. The holder further has a connection hole that is connected to the screw hole. The connection hole has an opening that is open at an outer surface of the holder and a connection part that is connected to the screw hole. The opening is positioned rearward of the connection part in the rotation direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2022-039024, filed on March 14, 2022, the entire disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a rotary tool and a method for manufacturing a machined product. An example of a rotary tool is a so-called milling tool. The milling tool can be used for milling processes such as face milling and end milling. [Background technology]

[0003] A known example of a rotary tool is a rotary tool (milling tool) described in Japanese Utility Model Application Laid-Open Publication No. 7-033517 (Patent Document 1). The rotary tool described in Patent Document 1 has a holder (tool body), a cutting insert (throw-away tip), and a screw. The holder has a screw hole into which the screw is threaded and a countersink communicating with the screw hole. The countersink is a part that makes it easier to discharge dust that tends to accumulate at the bottom of the screw hole to the outside.

[0004] However, in the rotary tool described in Patent Document 1, there is a risk that the removal of dust accumulated at the bottom of the screw hole may be insufficient. This is because, in the rotary tool described in Patent Document 1, dust is likely to enter from the opening of the countersink toward the bottom of the screw hole. Summary of the Invention

[0005] A non-limiting one-sided rotary tool of the present disclosure includes a holder extending from a front end to a rear end along a rotation axis and having a pocket located on the front end side, a cutting insert located in the pocket, and a screw for fixing the cutting insert to the holder. The pocket has a seat surface facing forward in the rotation direction of the rotation axis and a screw hole extending from the seat surface toward the rear in the rotation direction and into which the screw is fixed. The holder further has a connection hole connected to the screw hole. The connection hole has an opening that opens in the outer surface of the holder and a connection portion connected to the screw hole. The opening is located rearward of the connection portion in the rotation direction. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view of a non-limiting one-sided rotary tool of the present disclosure. [Figure 2] FIG. 2 is the same perspective view as FIG. 1, showing the screw holes and the connection holes in a see-through manner. [Figure 3] FIG. 2 is a perspective view of the rotary tool shown in FIG. 1, seen from another direction. [Figure 4] 4 is the same perspective view as FIG. 3, showing the screw holes and the connection holes in a see-through manner. [Figure 5] FIG. 2 is a plan view of the rotary tool shown in FIG. 1 as viewed from the tip side. [Figure 6] FIG. 6 is the same plan view as FIG. 5, showing the screw holes and connection holes in a see-through view. [Figure 7] FIG. 7 is a side view of the rotary tool shown in FIG. 6, as viewed from a direction VII. [Figure 8] FIG. 3 is a perspective view of a holder in the rotary tool shown in FIG. 2. [Figure 9] 9 is a perspective view of the holder shown in FIG. 8, seen from another direction. [Figure 10] FIG. 9 is a plan view of the holder shown in FIG. 8 as viewed from the tip end side. [Figure 11] 11 is a side view of the holder shown in FIG. 10 as viewed from the XI direction. [Figure 12]FIG. 1 is a perspective view of a non-limiting rotary tool of the present disclosure, showing the screw holes and connecting holes. [Figure 13] 13 is a perspective view of the rotary tool shown in FIG. 12 as seen from another direction, in which the screw holes and the connecting holes are not seen through. FIG. [Figure 14] FIG. 13 is a plan view of the rotary tool shown in FIG. 12 as viewed from the tip side. [Figure 15] FIG. 1 is a perspective view of a non-limiting rotary tool of the present disclosure, showing the screw holes and connecting holes. [Figure 16] FIG. 16 is a side view of the rotary tool shown in FIG. 15, and corresponds to FIG. [Figure 17] 16 is a perspective view of the rotary tool shown in FIG. 15, seen from a different direction, in which the screw holes and the connecting holes are not seen through. FIG. [Figure 18] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. [Figure 19] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. [Figure 20] 1 is a schematic diagram showing a step in a non-limiting method of manufacturing a one-sided machined product according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] <Rotary tools> A non-limiting aspect of the rotary tool 1 of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining the embodiment in a simplified form. Therefore, the rotary tool 1 may include any components not shown in the drawings referred to. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0008] The rotary tool 1 may include a holder 3, a cutting insert 5, and a screw 7, as a non-limiting example shown in FIGS.

[0009] The holder 3 may extend from the front end 3a to the rear end 3b along the rotation axis O1 and may have a pocket 9 located on the front end 3a side. The holder 3 is rotatable around the rotation axis O1. Note that the arrow Y1 in Figure 1 and other figures may indicate the rotation direction of the rotation axis O1, or may indicate the rotation direction of the holder 3 around the rotation axis O1.

[0010] The cutting insert 5 can be attached to the pocket 9. The pocket 9 may be open on the tip 3a side of the outer surface 11 of the holder 3. There may be only one pocket 9, or there may be multiple pockets 9.

[0011] When the holder 3 has a plurality of pockets 9, these pockets 9 may be positioned at equal intervals around the rotation axis O1, or may be positioned at uneven intervals. When there are a plurality of pockets 9, the number of pockets 9 may be approximately 2 to 20.

[0012] The size of the holder 3 is not limited to a specific value. For example, the length of the holder 3 in the direction along the rotation axis O1 may be set to approximately 40 to 100 mm. The width (diameter) of the holder 3 in the direction perpendicular to the rotation axis O1 may be set to approximately 40 to 350 mm.

[0013] The cutting insert 5 may simply be referred to as the insert 5. The insert 5 can be used to cut a workpiece in a cutting process. The insert 5 may be located in a pocket 9. When the holder 3 has a plurality of pockets 9, the rotary tool 1 may have a plurality of inserts 5, and one insert 5 may be located in each pocket 9.

[0014] The insert 5 may have a cutting edge 13. The rotary tool 1 is capable of performing cutting by bringing the cutting edge 13 of the insert 5 into contact with a workpiece. The insert 5 may be positioned in the pocket 9 such that at least a portion of the cutting edge 13 protrudes from the holder 3.

[0015] The insert 5 may be in the shape of a polygonal plate. The insert 5 may also have a through hole 15. The through hole 15 may penetrate the insert 5 in the thickness direction. The through hole 15 can function as a portion into which the screw 7 is inserted.

[0016] The screws 7 may be members that fix the inserts 5 to the holder 3. The number of the screws 7 may be the same as the number of the inserts 5.

[0017] The pocket 9 may have a seat 17 and a screw hole 19, as shown in a non-limiting example in FIG.

[0018] The seating surface 17 may face forward in the rotational direction Y1 of the rotation axis O1. The seating surface 17 can abut (contact) the insert 5 when the insert 5 is attached to the holder 3.

[0019] The seating surface 17 may be flat. Note that "flat" does not necessarily mean flat in the strict sense. If the seating surface 17 is flat, it may be roughly flat, and it may be slightly curved or have slight irregularities that are not noticeable when the holder 3 is viewed as a whole. If the seating surface 17 is flat, the seating surface 17 may have slight irregularities of about several tens of μm.

[0020] The screw hole 19 may extend rearward in the rotational direction Y1 from the seat surface 17. A screw 7 may be fixed in the screw hole 19 (see FIG. 4). The screw hole 19 may open in the seat surface 17. The insert 5 can be fixed to the holder 3 by inserting the screw 7 into the through hole 15 of the insert 5 and fixing the screw 7 in the screw hole 19.

[0021] The holder 3 may further have a connection hole 21. The connection hole 21 may be connected to the screw hole 19. The connection hole 21 may also be called a countersink.

[0022] The connecting hole 21 may be inclined with respect to the screw hole 19, as in a non-limiting example shown in Figure 10. In this case, it is easy to identify the boundary between the screw hole 19 and the connecting hole 21. The connecting hole 21 may not have a thread groove on its inner wall surface. In this case, it is also easy to identify the boundary between the screw hole 19 and the connecting hole 21. In other words, if the connecting hole 21 does not have a thread groove on its inner wall surface, the portion of the cylindrical portion extending rearward in the rotational direction Y1 from the seat surface 17 where the thread groove is located may be considered to be the screw hole 19, and the portion where the thread groove is not located may be considered to be the connecting hole 21.

[0023] Here, the connection hole 21 may have an opening 23 and a connection portion 25, as in a non-limiting example shown in Figures 3 and 4. The opening 23 may open on the outer surface 11 of the holder 3. The connection portion 25 may be a portion connected to the screw hole 19. The opening 23 may be located rearward of the connection portion 25 in the rotation direction Y1. Note that the outer surface 11 of the holder 3 where the opening 23 opens may be the surface of the holder 3 that is exposed to the outside when the rotary tool 1 is in use.

[0024] In the rotary tool disclosed in Patent Document 1, the recessed hole (connection hole) opens forward in the rotation direction Y1, so that when the rotary tool rotates during use, debris (such as cutting chips) easily gets into the connection hole.

[0025] When the opening 23 is located rearward of the connecting portion 25 in the rotational direction Y1, the connecting hole 21 opens rearward in the rotational direction Y1. Therefore, dust (such as chips) is less likely to enter the connecting hole 21 when the rotary tool 1 is in use. Therefore, with the rotary tool 1, dust is less likely to accumulate at the bottom of the screw hole 19.

[0026] Furthermore, when the opening 23 is located further rearward in the rotational direction Y1 than the connecting portion 25, the thickness of the holder 3 between the pocket 9 and the opening 23 is likely to be ensured. Therefore, the durability of the holder 3 is high. Furthermore, when the opening 23 is located further rearward in the rotational direction Y1 than the connecting portion 25, the screw hole 19 and the connecting hole 21 are likely to intersect at an obtuse angle. Therefore, chips generated when forming the screw hole 19 are also likely to be removed.

[0027] 2, the connection hole 21 may extend rearward in the rotational direction Y1 from the connection portion 25 toward the opening 23. In this case, even if chips enter the connection hole 21 from the opening 23, the chips can be easily discharged from the opening 23.

[0028] The connection hole 21 may extend linearly rearward in the rotation direction Y1 from the connection portion 25 toward the opening 23. In this case, chips that have entered the connection hole 21 from the opening 23 can be easily discharged.

[0029] As a non-limiting example shown in Figure 3, the outer surface 11 of the holder 3 may have a tip surface 27 and an outer peripheral surface 29. The tip surface 27 may be located on the side of the tip 3a. The outer peripheral surface 29 may extend from the tip surface 27 toward the rear end 3b. The outer peripheral surface 29 may be located on the outer peripheral side of the tip surface 27.

[0030] The opening 23 may be located on the tip surface 27, as in a non-limiting example shown in Figure 3. In this case, chips are less likely to enter the connecting hole 21 through the opening 23.

[0031] 7, the connection hole 21 may extend from the connection portion 25 toward the tip 3a as it approaches the opening 23. In this case, even if chips enter the connection hole 21 from the opening 23, the chips can be easily discharged from the opening 23.

[0032] The connection hole 21 may extend linearly from the connection portion 25 toward the tip 3a as it approaches the opening 23. In this case, chips that have entered the connection hole 21 from the opening 23 can be easily discharged.

[0033] The insert 5 may have a peripheral cutting edge 31 located on the outer periphery, as shown in a non-limiting example in FIG. 7. In other words, the cutting edge 13 may have a peripheral cutting edge 31 located on the outer periphery. The peripheral cutting edge 31 may have a primary role in cutting the workpiece. The peripheral cutting edge 31 may also be called a main cutting edge. The peripheral cutting edge 31 may have a linear shape that approaches the tip 3a as it approaches the rotation axis O1.

[0034] 3, the opening 23 may be located closer to the rotation axis O1 than the peripheral cutting edge 31. In this case, the thickness of the holder 3 can be easily ensured behind the peripheral cutting edge 31 in the rotation direction Y1. Therefore, the durability of the holder 3 is high.

[0035] 6, the connecting hole 21 may extend away from the outer peripheral surface 29 as it approaches the opening 23 from the connecting portion 25. In this case, it is easier to ensure a sufficient thickness of the holder 3 at the rear of the peripheral cutting edge 31 in the rotation direction Y1. Therefore, the durability of the holder 3 is high.

[0036] The tip surface 27 may have an inclined surface 33, as shown in a non-limiting example in FIG. 3. The inclined surface 33 may approach the rear end 3b as it approaches the rotation axis O1. The inclined surface 33 may also be located closer to the rotation axis O1 than the peripheral cutting edge 31. The opening 23 may be located on the inclined surface 33. In these cases, space is easily secured between the processing surface (finishing surface) and the opening 23. Therefore, chips are less likely to enter the connecting hole 21 from the opening 23. Even if chips do enter the connecting hole 21, the chips are less likely to become caught between the rotary tool 1 and the workpiece.

[0037] The opening 23 may be circular. The inner diameter of the opening 23 may be the same as the inner diameter of the opening of the screw hole 19 located on the seat surface 17 (see FIG. 9). In this case, chips are less likely to enter the connecting hole 21 from the opening 23. Note that the inner diameter of the opening 23 being the same as the inner diameter of the opening of the screw hole 19 does not necessarily mean that the two values ​​are exactly the same. For example, there may be a difference of about 10% between the two values.

[0038] The connection hole 21 may further have a recess 35 including the hole bottom, which is located farther from the opening 23 than the connection portion 25. When the connection portion 25 has the recess 35, chips are less likely to get into the screw hole 19. This is because, even if chips get into the connection hole 21 from the opening 23, the chips are likely to remain in the recess 35.

[0039] In the direction along the central axis of the connection hole 21, the depth of the recess 35 may be shorter than the length from the opening 23 to the connection portion 25. In this case, it is easy to prevent excessive chips from remaining in the recess 35, and it is easy to ensure the rigidity of the holder 3.

[0040] Examples of materials for the holder 3 include steel and cast iron. When the material for the holder 3 is steel, the holder 3 has high toughness.

[0041] Examples of the material of the insert 5 include cemented carbide and cermet. Examples of the cemented carbide composition include 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.

[0042] The cermet may be a sintered composite material in which a ceramic component is combined with a metal. An example of a cermet is a titanium compound mainly composed of titanium carbide (TiC) or titanium nitride (TiN). It goes without saying that the material of the insert 5 is not limited to the above composition.

[0043] The surface of the insert 5 may be coated with a coating using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. The coating composition may include, for example, titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al2O3).

[0044] Next, a non-limiting aspect of a rotary tool 1A according to the present disclosure will be described with reference to FIGS. 12 to 14. The following mainly describes the differences between the rotary tool 1A and the rotary tool 1, and detailed description of the same configuration as the rotary tool 1 may be omitted. Therefore, the description of the rotary tool 1 may be used to understand the configuration of the rotary tool 1A. This also applies to the rotary tool 1B described below.

[0045] In the rotary tool 1A, the openings 23 may be located on the outer peripheral surface 29, as in the non-limiting example shown in FIGS. 12 to 14. There is a risk of chips getting caught between the workpiece and the openings 23 near the openings 23. When the openings 23 are located on the outer peripheral surface 29, it is easy to prevent chips from getting caught on the finished surface. Therefore, machining accuracy is easy to improve.

[0046] Next, a non-limiting yet another rotary tool 1B according to the present disclosure will be described with reference to FIGS.

[0047] In the rotary tool 1B, similarly to the rotary tool 1A, the opening 23 may be located on the outer peripheral surface 29 (see FIG. 15). As a non-limiting example shown in FIG. 16, the connecting hole 21 may extend from the connecting portion 25 toward the rear end 3b as it approaches the opening 23. In these cases, it is easy to prevent chips from getting caught in the workpiece near the opening 23. Therefore, machining accuracy is easy to improve.

[0048] 17, the opening 23 may be located closer to the rear end 3b than the peripheral cutting edge 31. In this case, the thickness of the holder 3 behind the peripheral cutting edge 31 in the rotation direction Y1 is easily ensured. Therefore, the durability of the holder 3 is high.

[0049] <Method of manufacturing machined products> Next, a non-limiting method for manufacturing the one-surface machined product 101 according to the present disclosure will be described with reference to FIGS.

[0050] The machined product 101 may be produced by cutting a workpiece 103. A manufacturing method for the machined product 101 may include the following steps: (1) a step of rotating a rotary tool 1 typified by the above-mentioned non-limiting embodiment; (2) bringing the rotary tool 1 into contact with the workpiece 103; (3) a step of separating the rotary tool 1 from the workpiece 103; may have

[0051] Specifically, first, as in a non-limiting example shown in Fig. 18, the rotary tool 1 may be rotated in the Y1 direction and brought relatively close to the workpiece 103. Next, as in a non-limiting example shown in Fig. 19, the insert 5 (cutting edge 13) of the rotary tool 1 may be brought into contact with the workpiece 103 to cut the workpiece 103. Then, as in a non-limiting example shown in Fig. 20, the rotary tool 1 may be moved relatively away from the workpiece 103.

[0052] By going through the above steps, it is possible to obtain a machined product 101 with a highly accurate finished surface. Specifically, when the rotary tool 1 is used in the manufacturing method of the machined product 101, dust is less likely to accumulate at the bottom of the screw hole 19, and therefore excellent workability can be achieved. As a result, it is possible to obtain a machined product 101 with a highly accurate finished surface.

[0053] In the non-limiting example shown in FIGS. 18 to 20, the workpiece 103 is fixed and the rotary tool 1 is moved in each step, but the present invention is not limited to this configuration.

[0054] For example, in step (1), the workpiece 103 may be brought closer to the rotary tool 1. Similarly, in step (3), the workpiece 103 may be moved away from the rotary tool 1. When continuing the cutting process, the rotary tool 1 may be kept rotating, and the step of bringing the insert 5 (cutting edge 13) of the rotary tool 1 into contact with different locations on the workpiece 103 may be repeated.

[0055] Examples of the material of the workpiece 103 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0056] 18 to 20, a rotary tool 1 is used, but the present invention is not limited to this. For example, instead of the rotary tool 1, a rotary tool 1A or a rotary tool 1B may be used. [Explanation of symbols]

[0057] 1. Rotary tools 3. Holder 3a...Tip 3b...rear end 5. Cutting insert (insert) 7 screws 9 pockets 11...Outer surface 13 Cutting edge 15. Through hole 17···Seat 19 Screw hole 21 Connection hole 23. Opening 25 Connection 27...Tip surface 29...Outer surface 31...Peripheral blade 33...Slope surface 35. Recess 101...Cutting workpiece 103...Work material O1 Rotation axis Y1: Rotation direction

Claims

1. a holder extending from a front end to a rear end along a rotation axis and having a pocket located on the front end side; a cutting insert located in the pocket; a screw for fixing the cutting insert to the holder; The pocket is a bearing surface facing forward in the rotation direction of the rotation shaft; a screw hole extending from the seat surface toward the rear in the rotation direction and into which the screw is fixed, the holder further has a connection hole connected to the screw hole, The connection hole is an opening that opens in an outer surface of the holder; a connection portion connected to the screw hole, the opening is located rearward of the connection portion in the rotation direction and opens rearward in the rotation direction, The outer surface of the holder is a tip surface located on the tip side; an outer circumferential surface extending from the tip surface toward the rear end, The opening is located in the tip surface.

2. The rotary tool according to claim 1 , wherein the connection hole extends rearward in the rotation direction from the connection portion toward the opening.

3. The rotary tool according to claim 1 , wherein the connection hole extends from the connection portion toward the tip as it approaches the opening.

4. The cutting insert has a peripheral cutting edge located on the outer periphery side, The rotary tool according to claim 1 , wherein the opening is located closer to the rotation axis than the peripheral cutting edge.

5. The rotary tool according to claim 4 , wherein the connection hole extends so as to move away from the outer circumferential surface as it approaches the opening from the connection portion.

6. the tip end surface has an inclined surface that approaches the rear end as it approaches the rotation axis, The rotary tool of claim 1 , wherein the opening is located in the inclined surface.

7. A step of rotating the rotary tool according to any one of claims 1 to 6; bringing the rotary tool into contact with a workpiece; and removing the rotary tool from the workpiece.

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