Cutting tool and method for manufacturing cut workpiece

Abstract

This cutting tool has a holder, a cutting insert, a clamper, and a screw. The holder has a pocket positioned on the front end side. The screw extends from the front end side toward the rear end side along a third axis; the clamper is slidable in a direction along the third axis; and the pocket has a seating surface extending along the third axis.

Description

Cutting tool and method for manufacturing machined product

[0001] The present disclosure relates to a cutting tool used when cutting a workpiece such as a metal.

[0002] BACKGROUND ART Cutting tools used for cutting workpieces such as metals are known, for example, from Japanese Patent Application Laid-Open No. 2003-129994 and Japanese Patent Application Laid-Open No. 2003-129994.

[0003] The cutting tools described in Patent Documents 1 and 2 each include a holder, a cutting insert, a clamping member, and a screw. The holder has a pocket, and the cutting insert is installed in the pocket. In the cutting tools described in Patent Documents 1 and 2, the clamping member is slid using the screw to fix the cutting insert to the holder.

[0004] Japanese Patent Publication No. 2015-523229 Japanese Patent Publication No. 2017-159450

[0005] A cutting tool according to one aspect of the present disclosure has a shape extending along a first axis from the tip end to the rear end, and includes a holder having a pocket located on the tip side, a cutting insert located in the pocket and having a through hole opening in a direction along a second axis perpendicular to the first axis, a clamper inserted into the through hole and capable of restraining the cutting insert to the holder, and a screw located on the tip side and capable of being biased against the clamper, wherein the screw extends along a third axis from the tip side to the rear end side, the clamper is slidable in a direction along the third axis, and the pocket has a seat surface extending along the third axis.

[0006] 5 is an exploded perspective view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure. FIG. 6 is a perspective view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure. FIG. 7 is a top view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure. FIG. 8 is a view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure, viewed from the tip side in the direction of a first axis. FIG. 9 is a side view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure. FIG. 10 is an enlarged side view of a cutting insert and its surroundings. FIG. 11 is a cross-sectional view taken along VII-VII of FIG. 5. FIG. 12 is a schematic view showing a cross section of another example of a clamper, perpendicular to the third axis. FIG. 13 is a schematic view comparing the cross-sectional area of ​​a second portion in a cross section perpendicular to the second axis and the cross-sectional area of ​​a first portion in a cross section perpendicular to the third axis, of yet another example of a clamper. FIG. 14 is a top view showing a first step in a method for manufacturing a machined product according to a second embodiment of the present disclosure. FIG. 15 is a top view showing a first half of a second step in a method for manufacturing a machined product according to a second embodiment of the present disclosure. FIG. 16 is a top view showing a second half of a second step in a method for manufacturing a machined product according to a second embodiment of the present disclosure. FIG. 10 is a top view showing a third step in the method for manufacturing a machined product according to the second embodiment of the present disclosure.

[0007] The pocket has a seating surface that extends in a direction parallel to the central axis of the holder. In the cutting tools described in Patent Documents 1 and 2, the central axis of the screw is significantly inclined with respect to the seating surface.

[0008] Therefore, the force applied from the screw to the clamping member when tightening the screw tends to press the cutting insert against the seating surface. This means that the force of tightening the screw is dispersed, which may result in an insufficient force to restrain the cutting insert by the clamping member.

[0009] According to one aspect of the present disclosure, the cutting insert can be restrained with sufficient force by the clamper.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present disclosure. For convenience of explanation, the same reference numerals are used to designate components having the same functions as those previously described, and the description thereof may not be repeated.

[0011] For the sake of convenience, the drawings referred to below show only the main components necessary for explaining each embodiment in a simplified manner. Therefore, for example, the cutting tool 101 may include any components not shown in the drawings. The dimensions of the components in the drawings do not faithfully represent the dimensions and dimensional ratios of the actual components. These points are the same for both the cutting tool 101 and the method for manufacturing the machined product 301.

[0012] [Embodiment 1] Fig. 1 is an exploded perspective view showing a schematic configuration of a cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 2 is a perspective view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 3 is a top view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 4 is a view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure, viewed from the tip 5 side in the direction of the first axis A1. Fig. 5 is a side view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure.

[0013] The cutting tool 101 is used in cutting a workpiece to manufacture a machined product 301 (see FIG. 13 ), which will be described later. The cutting tool 101 may include a holder 1, a cutting insert 2, a clamper 3, and a screw 4.

[0014] The holder 1 may have a shape extending along the first axis A1 from the leading end 5 to the rear end 6. The shape may be a rod shape. In this application, the term "along" is not limited to two members extending parallel to each other, and the two members may extend at an inclination of 5° or less relative to each other. The holder 1 can be used to hold the cutting insert 2. The holder 1 may have a body 7 and a pocket 8. The leading end 5 and the rear end 6 may be the leading end and the rear end of the holder 1, respectively.

[0015] Examples of the shape of the main body 7 include a cylindrical shape and a polygonal prism shape. Examples of the material of the main body 7 include steel, cast iron, and aluminum alloy.

[0016] The size of the main body 7 may be set appropriately depending on the size of the workpiece. For example, the length of the main body 7 in the direction of the first axis A1 may be approximately 60 mm or more and 3500 mm or less. For example, the width of the main body 7 in a direction perpendicular to the first axis A1 may be approximately 6 mm or more and 250 mm or less. For example, if the main body 7 is cylindrical, the width of the main body 7 in the direction perpendicular to the first axis A1 may be interpreted as the diameter of the main body 7 in the direction perpendicular to the first axis A1.

[0017] The pocket 8 may be located on the side of the tip 5. The pocket 8 is a portion of the holder 1 to which the cutting insert 2 is attached. The cutting insert 2 can be attached to the pocket 8. The pocket 8 may be a recess formed on the side of the tip 5 of the main body 7 before the cutting insert 2 is attached.

[0018] The number of pockets 8 may be one or more. When there are more than one pockets 8, the number may be 2 to 10. In FIG. 1 and the like, one pocket 8 is formed for the main body 7.

[0019] The cutting insert 2 may be located in the pocket 8. The cutting insert 2 may have a through hole 9 that opens in a direction along a second axis A2 that is perpendicular to the first axis A1. The cutting insert 2 has a function of contacting a workpiece and cutting the workpiece.

[0020] 6 is an enlarged side view of the cutting insert 2 and its surroundings. An example of the shape of the cutting insert 2 includes, but is not limited to, a polygonal plate shape. The cutting insert 2 may have a leading end surface 10 located on the leading end 5 side, an upper surface 11 extending from the leading end surface 10 toward the rear end 6, a side surface 12 adjacent to the leading end surface 10 and the upper surface 11, and a cutting edge 13 located at the intersection of the leading end surface 10 and the upper surface 11. The cutting insert 2 may be positioned in the pocket 8 so that the cutting edge 13 protrudes on the leading end 5 side.

[0021] The cutting tool 101 can perform cutting by bringing the cutting edge 13 into contact with the workpiece. Protruding the cutting edge 13 laterally is advantageous in that only the cutting edge 13 and its vicinity can be brought into contact with the workpiece.

[0022] Examples of the material of the cutting insert 2 include cemented carbide and cermet.

[0023] Examples of cemented carbide compositions include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co may be produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering the mixture. WC-TiC-Co may be produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co may be produced by adding tantalum carbide (TaC) to WC-TiC-Co.

[0024] The cermet may be a sintered composite material in which a ceramic component is combined with a metal. Specifically, the cermet may be a cermet containing a titanium compound as a main component. Examples of the cermet containing a titanium compound as a main component include titanium carbide (TiC) and titanium nitride (TiN).

[0025] The clamper 3 may be inserted into the through hole 9. The clamper 3 may be capable of restraining the cutting insert 2 to the holder 1. The screw 4 may be located on the side of the front end 5 and capable of biasing the clamper 3. Specifically, when the screw 4 is attached to the holder 1, the screw 4 may come into contact with the clamper 3 and may push the clamper 3 from the side of the front end 5 toward the side of the rear end 6.

[0026] The screw 4 may extend along a third axis A3 from the front end 5 toward the rear end 6. The clamper 3 may be slidable in a direction along the third axis A3, and the pocket 8 may have a seat surface 14 extending along the third axis A3.

[0027] Although the bearing surface 14 is illustrated as extending along the third axis A3 in a side view of the cutting tool 101, this is not limiting. The bearing surface 14 may extend along the third axis A3 in a side view of the cutting tool 101 or in another specific viewpoint. In other words, the normal direction of the bearing surface 14 is not particularly limited.

[0028] A first hole 15, a second hole 16, an opening 17, and a space 18 are formed on the tip 5 side of the holder 1. The first hole 15 opens along the third axis A3. The second hole 16 opens along the second axis A2. The opening 17 is formed closer to the rear end 6 than the first hole 15 and at a position along the third axis A3 relative to the first hole 15, and opens along the third axis A3. The space 18 is formed at a position surrounded by the first hole 15, the second hole 16, and the opening 17.

[0029] The cutting insert 2 can be fixed to the clamper 3 by fitting the clamper 3 into the through hole 9. The first condition is that the cutting insert 2 is fixed to the clamper 3.

[0030] The clamper 3 is introduced into the space 18 through the second hole 16. The screw 4 is inserted into the first hole 15. When the screw 4 inserted into the first hole 15 is tightened while the clamper 3 is introduced into the space 18, the screw 4 urges the clamper 3. As a result, the clamper 3 slides from the front end 5 toward the rear end 6 in the direction along the third axis A3 and fits into the opening 17. The second condition is that the clamper 3 is fitted into the opening 17.

[0031] When both the first condition and the second condition are satisfied, the clamper 3 can restrain the cutting insert 2 relative to the holder 1. In a state in which the clamper 3 restrains the cutting insert 2 relative to the holder 1, the seating surface 14 may correspond to a surface on which the cutting insert 2 is installed (placed).

[0032] To release the clamper 3 from restraining the cutting insert 2 relative to the holder 1, the screw 4 inserted into the first hole 15 is loosened. This causes the clamper 3 to slide from the rear end 6 toward the front end 5 in the direction along the third axis A3, thereby releasing the second condition.

[0033] After careful consideration, the inventors of the present application discovered that when fixing the cutting insert 2 to the holder 1 using a screw 4, the force that fixes the holder 1, cutting insert 2, and clamper 3 to each other is more effective than the force that presses the cutting insert 2 against the seat surface 14.

[0034] According to the cutting tool 101, most of the force generated when the screw 4 is tightened acts in a direction along the third axis A3. From the above-described operating mechanisms of the holder 1, cutting insert 2, clamper 3, and screw 4, it can be seen that in the cutting tool 101, the force in the direction along the third axis A3 can be effectively utilized as a force to fix the holder 1, cutting insert 2, and clamper 3 to each other. Therefore, according to the cutting tool 101, the clamper 3 can restrain the cutting insert 2 with sufficient force.

[0035] When the cutting tool 101 is viewed from the side, the third axis A3 may be parallel to the first axis A1 or may be inclined with respect to the first axis A1. When the cutting tool 101 is viewed from the side, if the third axis A3 is parallel to the first axis A1, dispersion of the force generated when the screw 4 is fastened is suppressed, and the cutting insert 2 can be easily firmly fixed toward the rear end 6.

[0036] The holder 1 is located behind the seating surface 14 in the attachment direction of the cutting insert 2 into the pocket 8, and has a side wall 19 that is approximately perpendicular to the seating surface 14. Figure 7 is a cross-sectional view taken along line VII-VII of Figure 5. When the cutting tool 101 is viewed from above, the third axis A3 may be inclined in a direction D1 that moves away from the seating surface 14 as it approaches the rear end 6. The direction D1 may be a direction from the upstream side to the downstream side in the attachment direction of the cutting insert 2 into the pocket 8. This causes the force generated by tightening the screw 4 to further act in a direction that presses the cutting insert 2 against the side wall 19, thereby firmly restraining the cutting insert 2.

[0037] The clamper 3 has a first portion 20 and a second portion 21. The first portion 20 extends along the third axis A3 and may be rod-shaped. The second portion 21 extends along the second axis A2 from the first portion 20 toward the through hole 9 of the cutting insert 2 and may be rod-shaped. The screw 4 may abut against an end 22 of the first portion 20 on the tip 5 side.

[0038] 8 is a schematic diagram showing a cross section perpendicular to the third axis A3 of another example of the clamper 3. The first portion 20 may have an elliptical shape in the cross section perpendicular to the third axis A3. When the shape of the first portion 20 in the cross section perpendicular to the third axis A3 is elliptical, the width of the first portion 20 is small in the minor axis direction D2 of the ellipse, allowing the holder 1 to be formed thick. Therefore, a high-strength holder 1 that is less susceptible to cracking in the minor axis direction D2 can be realized.

[0039] As described above, the cutting insert 2 may have a leading end surface 10 located on the leading end 5 side and an upper surface 11 extending from the leading end surface 10 toward the rear end 6. In the first portion 20, a width W1 in a direction parallel to the upper surface 11 may be smaller than a width W2 in a direction perpendicular to the upper surface 11 in a cross section perpendicular to the third axis A3.

[0040] It is desirable that the first hole 15, the second hole 16, the opening 17, and the space 18 be formed as close as possible to the seating surface 14. This is because the second portion 21 can be formed short along the second axis A2, thereby reducing the risk of the second portion 21 breaking. On the other hand, if the first hole 15, the second hole 16, the opening 17, and the space 18 are formed too close to the seating surface 14, it becomes difficult to form the holder 1 thick in the direction parallel to the upper surface 11.

[0041] Since the width W1 is smaller than the width W2, the holder 1 can be formed thick in the direction parallel to the upper surface 11, thereby reducing the risk of the second portion 21 breaking and realizing a high-strength holder 1.

[0042] 9 is a schematic diagram comparing the cross-sectional area S1 of the second portion 21 in a cross section perpendicular to the second axis A2 with the cross-sectional area S2 of the first portion 20 in a cross section perpendicular to the third axis A3 in yet another example of the clamper 3. The cross-sectional area S1 of the second portion 21 in a cross section perpendicular to the second axis A2 may be larger than the cross-sectional area S2 of the first portion 20 in a cross section perpendicular to the third axis A3. This reduces the risk of the second portion 21 breaking.

[0043] The cutting insert 2 has a rear end surface 23 located on the side of the rear end 6, and the pocket 8 has a wall surface 24 abutting the rear end surface 23, and the rear end surface 23 and the wall surface 24 may be inclined in a direction approaching the seat surface 14 as they approach the rear end 6.

[0044] [Embodiment 2] Fig. 10 is a top view showing a first step in a method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure. Fig. 11 is a top view showing a first half of a second step in the method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure. Fig. 12 is a top view showing a second half of the second step in the method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure. Fig. 13 is a top view showing a third step in the method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure.

[0045] The first step is a step of rotating the workpiece 201. The workpiece 201 may be rotated around a rotation axis A4 of the workpiece 201. Examples of materials for the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0046] The second step is a step of bringing the cutting tool 101 into contact with the rotating workpiece 201. The cutting tool 101 may be moved to bring the cutting tool 101 relatively close to the rotating workpiece 201. The cutting edge 13 of the cutting tool 101 may be brought into contact with the workpiece 201 to cut the workpiece 201.

[0047] The third step is a step of separating the cutting tool 101 from the workpiece 201. The cutting tool 101 may be moved to separate the cutting tool 101 from the workpiece 201, thereby obtaining a machined product 301.

[0048] According to the manufacturing method of the machined product 301, the cutting tool 101 in which the cutting insert 2 is restrained with sufficient force by the clamper 3 is used, thereby reducing the risk of the cutting insert 2 becoming loose during manufacturing of the machined product 301. Therefore, according to the manufacturing method of the machined product 301, the workpiece 201 can be cut with excellent machining accuracy, and the machined product 301 having a highly accurate machined surface can be obtained.

[0049] In the second step, the workpiece 201 may be brought closer to the cutting tool 101. In the third step, the workpiece 201 may be moved away from the cutting tool 101. To continue the cutting process, the workpiece 201 may be kept rotating, and the step of bringing the cutting blade 13 into contact with different locations on the workpiece 201 may be repeated.

[0050] Although the cutting tool 101 and the method for manufacturing the machined product 301 have been exemplified above, this aspect is not limited to the above-described embodiment, and any method may be used as long as it does not deviate from the gist of this aspect.

[0051] The cutting tool 101 may be a turning tool, but may also be, for example, a milling tool. When the cutting tool 101 is a milling tool, the cutting tool 101 may be rotated in the first step of the manufacturing method of the machined product 301.

[0052] [Summary] A cutting tool according to aspect 1 of the present disclosure has a shape extending along a first axis from the tip end to the rear end, and includes a holder having a pocket located on the tip end side, a cutting insert located in the pocket and having a through hole opening in a direction along a second axis perpendicular to the first axis, a clamper inserted into the through hole and capable of restraining the cutting insert to the holder, and a screw located on the tip end side and capable of biasing the clamper, wherein the screw extends along a third axis from the tip end side to the rear end side, the clamper is slidable in a direction along the third axis, and the pocket has a seat extending along the third axis.

[0053] A cutting tool according to Aspect 2 of the present disclosure is the same as Aspect 1, but has the following features: the cutting insert has a tip surface located on the tip end side, an upper surface extending from the tip surface toward the rear end, side surfaces adjacent to the tip surface and the upper surface, and a cutting edge located at an intersection of the tip surface and the upper surface, and when viewed from the side, the third axis is parallel to the first axis.

[0054] A cutting tool according to Aspect 3 of the present disclosure has the following features: In Aspect 2, the third axis is inclined in a direction away from the bearing surface as it approaches the rear end, when viewed from above.

[0055] A cutting tool according to Aspect 4 of the present disclosure is any one of Aspects 1 to 3, and has the following feature: the clamper has a rod-shaped first portion extending along the third axis, and a rod-shaped second portion extending from the first portion toward the through hole of the cutting insert along the second axis.

[0056] A cutting tool according to Aspect 5 of the present disclosure is the cutting tool of Aspect 4, which has the following features: The screw abuts against an end portion of the first portion on the tip side.

[0057] A cutting tool according to Aspect 6 of the present disclosure is the cutting tool of Aspect 4 or 5, which has the following features: The first portion has an elliptical shape in a cross section perpendicular to the third axis.

[0058] A cutting tool according to Aspect 7 of the present disclosure is the cutting tool of Aspect 6, which has the following features: the cutting insert has a front end surface located on the front end side and an upper surface extending from the front end surface toward the rear end, and the first portion has a width in a direction parallel to the upper surface that is smaller than a width in a direction perpendicular to the upper surface in a cross section perpendicular to the third axis.

[0059] The cutting tool according to Aspect 8 of the present disclosure is the cutting tool of any one of Aspects 4 to 7, and has the following feature: A cross-sectional area of ​​the second portion in a cross section perpendicular to the second axis is larger than a cross-sectional area of ​​the first portion in a cross section perpendicular to the third axis.

[0060] A cutting tool according to Aspect 9 of the present disclosure is any one of Aspects 1 to 8, and has the following features: the cutting insert has a rear end surface located on the rear end side, the pocket has a wall surface abutting against the rear end surface, and the rear end surface and the wall surface are inclined in a direction approaching the seat surface as they approach the rear end.

[0061] A manufacturing method for a machined product according to aspect 10 of the present disclosure is in any of aspects 1 to 9, and includes the steps of rotating a workpiece, bringing the cutting tool into contact with the rotating workpiece, and removing the cutting tool from the workpiece.

[0062] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0063] DESCRIPTION OF SYMBOLS 1 Holder 2 Cutting insert 3 Clamp 4 Screw 5 Tip 6 Rear end 7 Body 8 Pocket 9 Through hole 10 Tip surface 11 Top surface 12 Side surface 13 Cutting edge 14 Seat surface 15 First hole 16 Second hole 17 Opening 18 Space 19 Side wall 20 First portion 21 Second portion 22 Tip side end portion of first portion 23 Rear end surface 24 Wall surface 101 Cutting tool 201 Workpiece 301 Machined product A1 First axis A2 Second axis A3 Third axis A4 Rotation axis of workpiece D1 Direction away from seat surface D2 Minor axis direction of ellipse S1, S2 Cross-sectional area W1, W2 Width

Claims

1. A holder having a shape that extends along a first axis from the tip to the rear end, and having a pocket located on the side of the tip, A cutting insert located in the aforementioned pocket and having a through hole that opens in a direction along a second axis perpendicular to the first axis, A clamper that is inserted into the through hole and can restrain the cutting insert to the holder, It has a screw located on the tip side that can bias the clamper, The screw extends along the third axis from the tip side toward the rear end side, The clamper is slidable in a direction along the third axis, The pocket is a cutting tool having a seating surface extending along the third axis.

2. The aforementioned cutting insert is The tip surface located on the side of the aforementioned tip, An upper surface extending from the aforementioned front surface toward the aforementioned rear end, The tip surface and the side surface adjacent to the top surface, It has a cutting edge located at the intersection of the tip surface and the upper surface, The cutting tool according to claim 1, wherein, when viewed from the side, the third axis is parallel to the first axis.

3. The cutting tool according to claim 2, wherein, when viewed from above, the third axis is inclined in a direction away from the seating surface as it approaches the rear end.

4. The aforementioned clamper is A rod-shaped first portion extending along the third axis, The cutting tool according to claim 1, further comprising: a rod-shaped second portion extending along the second axis from the first portion toward the through hole of the cutting insert.

5. The cutting tool according to claim 4, wherein the screw abuts against the end on the tip side of the first portion.

6. The cutting tool according to claim 4, wherein the first portion has an elliptical shape in a cross-section perpendicular to the third axis.

7. The aforementioned cutting insert is The tip surface located on the side of the aforementioned tip, It has an upper surface that extends from the front surface toward the rear end, The cutting tool according to claim 6, wherein the first portion, in a cross-section perpendicular to the third axis, has a width in a direction parallel to the upper surface that is smaller than the width in a direction perpendicular to the upper surface.

8. The cutting tool according to claim 4, wherein the cross-sectional area of ​​the second portion in a cross-section perpendicular to the second axis is greater than the cross-sectional area of ​​the first portion in a cross-section perpendicular to the third axis.

9. The cutting insert has a rear end surface located on the rear end side, The pocket has a wall surface that abuts against the rear end surface, The cutting tool according to claim 1, wherein the rear end surface and the wall surface are inclined in a direction that approaches the seat surface as they approach the rear end.

10. The process of rotating the workpiece, A step of bringing a cutting tool according to any one of claims 1 to 9 into contact with the rotating workpiece, A method for manufacturing a machined workpiece, comprising the step of separating the cutting tool from the workpiece.