WO2024224816A1 - Cutting insert, cutting tool, and method for manufacturing machined product - Google Patents

Abstract

For the automation of insert replacement, there is a need for an insert that can be stably held. A cutting insert (1) based on an aspect of the present disclosure includes a body (3) that is detachably attached to a holder. The body includes: an upper surface (5); a lower surface (7) that is positioned opposite the upper surface; side surfaces (9) that are connected to the upper surface and the lower surface; a cutting edge (11) that is positioned at the intersection between the upper surface and the side surfaces; a fixing hole (17) that opens to the upper surface and the lower surface, and into which a fixing member for fixing the body to the holder can be inserted; and a plurality of through openings (19) that open to the upper surface and the lower surface, and are positioned away from the fixing hole.

Description

Method for manufacturing cutting insert, cutting tool, and machined product

The present disclosure relates to a cutting insert, a cutting tool, and a method for manufacturing a machined product. Examples of cutting tools include rotary tools and turning tools. Examples of rotary tools include milling tools. The turning tools can be used for milling processes such as face milling and end milling. Examples of turning tools include external diameter machining tools, internal diameter machining tools, grooving tools, and cut-off tools.

In recent years, with the growing demand for automation in production sites (so-called smart factories), there has been an increasing demand for automating the replacement of cutting inserts (hereinafter simply referred to as inserts). For example, Patent Documents 1 and 2 propose a configuration in which a recess is provided on the top surface of the insert in order to improve the positioning accuracy when attaching the insert to the holder.

International Publication No. WO 1998/029211 European Patent Publication No. 0599393

A cutting insert according to one aspect of the present disclosure has a body that is detachably attached to a holder. The body has an upper surface, a lower surface opposite the upper surface, a side surface connected to the upper surface and the lower surface, a cutting edge located at the intersection of the upper surface and the side surface, fixing holes that open on the upper surface and the lower surface and into which a fixing member for fixing the body to the holder can be inserted, and a plurality of through openings that open on the upper surface and the lower surface and are located away from the fixing holes.

FIG. 1 is a perspective view of a cutting tool according to an embodiment of the present disclosure. FIG. 2 is an enlarged view of region II shown in FIG. 2 is a plan view of the cutting tool shown in FIG. 1 as viewed from a first end side. FIG. FIG. 2 is a perspective view of an insert in the cutting tool shown in FIG. 1 . FIG. 5 is a top view of the insert shown in FIG. 4 . FIG. 6 is an enlarged view of region VI shown in FIG. 5 . FIG. 6 is a side view of the insert shown in FIG. 5 as viewed from the A1 direction. 8 is a cross-sectional view taken along line VIII-VIII of the insert shown in FIG. 5. FIG. 2 is a schematic diagram showing a step of a manufacturing method of a machined product according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram showing a step of a manufacturing method of a machined product according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram showing a step of a manufacturing method of a machined product according to an embodiment of the present disclosure.

In automating insert replacement, it is necessary not only to improve the positioning accuracy when attaching the insert to the holder, but also to stably hold the insert. However, the above-mentioned Patent Documents 1 and 2 make no mention of stably holding the insert. Therefore, there is a demand for an insert that can be stably held in automating insert replacement.

The cutting insert 1 (insert 1), cutting tool 101, and method for manufacturing a machined product according to the embodiments of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, each of the drawings referred to below shows a simplified version of only the components necessary for explaining the embodiments. Therefore, the insert 1, cutting tool 101, and method for manufacturing a machined product according to the embodiments of the present disclosure may include any components not shown in each of the drawings referred to. Furthermore, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of each member, etc.

<Cutting tools>
1, a cutting tool 101 according to an example of the present disclosure is a rotary tool used for turning. In addition to rotary tools, the cutting tool 101 may be a turning tool used for turning such as external diameter machining, internal diameter machining, and grooving.

The cutting tool 101 may have a holder 103 and an insert 1. The insert 1 in the cutting tool 101 is a member that comes into contact with a workpiece and cuts the workpiece. The holder 103 is a member that holds the insert 1 and is attached to a machine tool.

In the example shown in FIG. 1, the holder 103 has a cylindrical shape extending from a first end 103a to a second end 103b along the rotation axis O1. In FIG. 1 and other figures, the direction of rotation about the rotation axis O1 is indicated by Y1. If the cutting tool 101 is a tool used for turning as described above, the rotation axis O1 may be replaced with the central axis.

The holder 103 may have a pocket 105 located on the side of the first end 103a. There may be only one pocket 105, or there may be multiple pockets 105 as in the example shown in FIG. 1. As in the example shown in FIG. 1, the multiple pockets 105 may each open to the outer circumferential surface of the holder 103 and the end face on the side of the first end 103a. As in the example shown in FIG. 3, when the cutting tool 101 is viewed from the front from the side of the second end 103b, the multiple pockets 105 may be arranged at equal or unequal intervals.

As is clear from FIG. 1 and other figures, the holder 103 has multiple pockets 105, so the holder 103 does not have to be cylindrical in the strict sense. The pockets 105 are spaces in which the insert 1 is positioned. The pockets 105 may also be used as spaces through which chips generated during cutting to manufacture machined products can flow.

The holder 103 may be made of steel, cast iron, or the like. For example, from the viewpoint of increasing the toughness of the holder 103, steel may be used among these materials.

The insert 1 is located in the pocket 105 and is removably attached to the holder 103 using a fixing member 107. Examples of the fixing member 107 include a clamp member and a screw. In a non-limiting example shown in FIG. 2, a screw is used as the fixing member 107, and the insert 1 is fixed to the holder 103 by the screw.

<Insert>
4 and 5 , the insert 1 according to the example of the present disclosure has a main body 3 that is detachably attached to a holder 103. The main body 3 has a polygonal plate shape and has an upper surface 5, a lower surface 7, a side surface 9, and a cutting edge 11, as in the example shown in FIG.

The upper surface 5 may be polygonal and have multiple corners 5a and multiple sides 5b. The upper surface 5 may be located relatively forward in the rotational direction Y1 of the insert 1 when the insert 1 is attached to the holder 103. The upper surface 5 may be shaped with 180° rotational symmetry with respect to the center of the upper surface 5, as in the example shown in FIG. 5. The center of the upper surface 5 can be identified, for example, by the intersection of the diagonals of the upper surface 5. The lower surface 7 may be located on the opposite side of the upper surface 5, and may be located relatively backward in the rotational direction Y1 of the insert 1 when the insert 1 is attached to the holder 103.

As shown in one example in FIG. 7, the side surface 9 of the insert 1 may be located between the upper surface 5 and the lower surface 7. The side surface 9 may be connected to each of the upper surface 5 and the lower surface 7. In the example shown in FIG. 5, since the upper surface 5 is polygonal, the side surface 9 has a flat surface area located along the edge 5b of the upper surface 5 and a convex surface area located along the corner 5a of the upper surface 5.

The example insert 1 shown in FIG. 4 has a generally rectangular plate shape, with the upper surface 5 and the lower surface 7 each being generally rectangular. When the upper surface 5 and the lower surface 7 have the above configuration, the side surface 9 has four flat surface areas and four convex surface areas. The shape of the insert 1 is not limited to the above configuration. For example, the upper surface 5 may not be rectangular, but may be, for example, generally triangular, generally pentagonal, or generally hexagonal.

The insert 1 has an upper cutting edge 13 as a cutting edge 11 located at the intersection of the top surface 5 and the side surface 9. The upper cutting edge 13 may be located over the entire intersection of the top surface 5 and the side surface 9, or may be located over only a portion of this intersection. When performing cutting using the upper cutting edge 13, since the top surface 5 is located forward in the rotation direction Y1, the top surface 5 can function as a scooping surface. In addition, at this time, the side surface 9 can function as a clearance surface.

In addition to the upper cutting edge 13, the insert 1 may have a lower cutting edge 15 as a cutting edge 11 located at the intersection of the lower surface 7 and the side surface 9. The lower cutting edge 15 may be located over the entire intersection of the lower surface 7 and the side surface 9, or may be located over only a portion of this intersection. When performing cutting using the lower cutting edge 15, since the lower surface 7 is located forward in the rotation direction Y1, the lower surface 7 can function as a scooping surface. In addition, at this time, the side surface 9 can function as a clearance surface.

In one cutting process, either the upper cutting edge 13 or the lower cutting edge 15 is used. For example, when the lower surface 7 of the insert 1 abuts against the pocket 105, the upper cutting edge 13 is used for cutting. If the upper cutting edge 13 wears down to a predetermined amount or more, the insert 1 may be removed from the pocket 105, turned upside down (front and back), and then reattached to the pocket 105. In this case, the upper surface 5 of the insert 1 abuts against the pocket 105, and the lower cutting edge 15 can be used for cutting.

The main body 3 may also have a fixing hole 17 and a plurality of through openings 19. These fixing holes 17 and the plurality of through openings 19 are through holes that open on the upper surface 5 and the lower surface 7, respectively.

The fixing hole 17 in the insert 1 is a portion into which a fixing member 107 can be inserted to fix the insert 1 (main body 3) when attaching or detaching the insert 1 to the holder 103 (see FIG. 2). In the example shown in FIG. 8, the fixing holes 17 open at the center of the upper surface 5 and at the center of the lower surface 7. In the cutting tool 101 described above, a screw, which is the fixing member 107, is inserted into the fixing hole 17 and fixed to the pocket 105, thereby fixing the insert 1 to the holder 103.

The end of the fixing hole 17 on the side of the upper surface 5 may be tapered so that the inner diameter increases as it approaches the upper surface 5. Similarly, the end of the fixing hole 17 on the side of the lower surface 7 may be tapered so that the inner diameter increases as it approaches the lower surface 7. In this case, the fixing member 107 can easily come into contact with the tapered portion, and the insert 1 can be stably fixed to the holder 103.

As shown in the example in FIG. 3, the pocket 105 in the holder 103 has a restraining seat 109 against which the lower surface 7 of the insert 1 abuts, and a restraining side surface 111 against which the side surface 9 of the insert 1 abuts. For example, the restraining seat 109 may be a square shape corresponding to the lower surface 7, and the restraining side surface 111 may be composed of two flat surface areas corresponding to the two flat surface areas on the side surface 9.

The restraining seat 109 may also be provided with a screw hole into which a fixing member 107 (screw) is screwed. The screw hole includes the central axis of the fixing hole 17 in the insert 1 and extends in a direction along the central axis. When a screw is used as the fixing member 107, the screw is inserted into the fixing hole 17 in the insert 1 and screwed into a screw hole formed in the restraining seat 109 of the pocket 105 in the holder 103.

<Through-hole>
The multiple through openings 19 in the insert 1 are portions that can be used to grip the insert 1 when attaching or detaching the insert 1 to or from the holder 103. By having such multiple through openings 19, the main body 3 can be gripped when attaching or detaching the main body 3 to or from the holder 103. For example, a gripping member such as a pin can be inserted into at least two of the multiple through openings 19 to pinch the main body 3.

Furthermore, in the example shown in FIG. 5, each of the multiple through openings 19 is located away from the fixing hole 17. Therefore, a distance can be secured between the gripping member that grips the main body 3 and the robot hand that attaches and removes the fixing member. This allows the fixing member 107 to be removed while gripping the main body 3, allowing for stable automation of the replacement of the insert 1. Hereinafter, each of the multiple through openings 19 will also be simply referred to as multiple through openings 19.

Here, since the multiple through openings 19 are through holes that open on both the upper surface 5 and the lower surface 7, the main body 3 can be gripped when attaching or detaching the main body 3 to the holder 103 regardless of whether the upper cutting edge 13 or the lower cutting edge 15 is being used. Also, the portion for gripping the main body 3 is not formed by the side surface 9 but by the multiple through openings 19 described above. Therefore, the cutting tool 101 is highly versatile for the following reasons.

In other words, when the insert 1 is attached to or detached from the holder 103, the side surface 9 of the insert 1 abuts against the pocket 105 (restraining side surface 111). If a portion for gripping the main body 3 is formed on the side surface 9, the area of the side surface 9 of the insert 1 that abuts against the pocket 105 is restricted in order to secure this portion. Also, in order to secure an area of the side surface 9 of the insert 1 that abuts against the pocket 105, the area for gripping the main body 3 is restricted.

In this way, when the portion that grips the main body 3 is formed on the side surface 9, either the area that abuts against the pocket 105 on the side surface 9 of the insert 1 or the portion that grips the main body 3 is necessarily restricted, resulting in restrictions on the structural design of the cutting tool 101. However, when the portion that grips the main body 3 is configured with multiple through openings 19 that open on both the upper surface 5 and the lower surface 7, the above restrictions do not occur, and the tool is highly versatile.

As shown in the example in FIG. 5, in the insert 1, the inner diameter of the multiple through openings 19 may be smaller than the inner diameter of the fixing hole 17. By making the inner diameter of the fixing hole 17 relatively large, the outer diameter of the portion of the fixing member 107 that is inserted into the fixing hole 17 can be made large. This increases the rigidity of the fixing member 107, and allows the insert 1 to be stably fixed to the holder 103. By making the inner diameter of the multiple through openings 19 relatively small, the second moment of area of the main body 3 is easily ensured. Therefore, even if multiple through openings 19 are provided, it is easy to avoid a significant decrease in the rigidity of the insert 1.

When attaching or detaching the main body 3 to or from the holder 103, for example, the main body 3 can be clamped by inserting a pin into the multiple through openings 19, but in view of the purpose of gripping the main body 3, high rigidity is not required for the pin. Therefore, even if the inner diameter of the multiple through openings 19 is relatively small, the purpose of gripping the main body 3 when attaching or detaching the main body 3 to or from the holder 103 can be achieved.

The multiple through openings 19 may extend linearly from the upper surface 5 to the lower surface 7, as in the example shown in FIG. 8. In this case, the gripping member can be inserted into the multiple through openings 19 at a sufficient length, and the main body 3 can be gripped stably. In addition, the pin does not get caught on the inner surface of the through opening 19, and the gripping member can be easily inserted.

In the above case, the entire through opening 19 may extend linearly from the upper surface 5 to the lower surface 7, or a portion of the through opening 19 may extend linearly from the upper surface 5 to the lower surface 7. For example, as shown in the example in FIG. 8, the end of the through opening 19 on the upper surface 5 side may have a tapered shape with an inner diameter that increases as it approaches the upper surface 5. Similarly, the end of the through opening 19 on the lower surface 7 side may have a tapered shape with an inner diameter that increases as it approaches the lower surface 7. In this case, the gripping member can be easily inserted into the through opening 19.

When the fixing hole 17 and the through opening 19 each have the tapered portion as described above, these portions are not limited to a specific size, and may have the following configuration, for example. As shown in the example in FIG. 8, the width H1 in the direction from the upper surface 5 to the lower surface 7, i.e., the height direction, of the tapered portion of the fixing hole 17 may be greater than the width H2 in the height direction of the tapered portion of the through opening 19.

The width H1 of the fixing hole 17 is relatively large, so that the insert 1 can be stably fixed to the holder 103. Furthermore, the width H2 of the through opening 19 is relatively small, so that the length of the linearly extending portion of the through opening 19 is easily ensured to be long. Therefore, the main body 3 can be stably gripped by the gripping member.

Also, as shown in the example in FIG. 5, the multiple through openings 19 have a first opening 21 and a second opening 23, and when the top surface 5 is viewed from the front, these first openings 21 and second openings 23 may be positioned rotationally symmetrically with respect to the fixing hole 17. When the top surface 5 is viewed from the front, these first openings 21 and second openings 23 may be positioned rotationally symmetrically with respect to the center of the fixing hole 17.

When the first opening 21 and the second opening 23 are positioned rotationally symmetrically with respect to the fixing holes 17 that open at the center of the upper surface 5 and the center of the lower surface 7, respectively, the center of gravity is located on an imaginary line connecting the first opening 21 and the second opening 23. Therefore, the insert 1 can be stably held when attaching and detaching the insert 1 to the holder 103. In addition, uneven loads applied to the holding member inserted into the first opening 21 and the holding member inserted into the second opening 23 are suppressed.

As described above, when the upper surface 5 has a polygonal shape having multiple corners 5a and the fixing hole 17 opens in the center of the upper surface 5, the multiple through openings 19 may be located between the fixing hole 17 and the corners 5a. Compared to between the fixing hole 17 and the sides 5b on the upper surface 5, a larger space is likely to be secured between the fixing hole 17 and the corners 5a on the upper surface 5. Therefore, even when multiple through openings 19 are provided, the durability of the insert 1 is unlikely to decrease significantly.

In this case, as shown in the example in FIG. 6, the multiple through openings 19 may be located closer to the fixing hole 17 than the corner 5a. In other words, the distance D2 between the through openings 19 and the fixing hole 17 may be smaller than the distance D1 between the through openings 19 and the corner 5a. In this case, even when multiple through openings 19 are provided, the durability of the insert 1 is less likely to decrease. This is because, in cutting the workpiece, a cutting load is applied to the cutting edge 11, and even when a cutting load is applied to the corner 5a where the cutting edge 11 is located, the distance D1 between the through openings 19 and the corner 5a is relatively large.

The shape of the multiple through openings 19 when the top surface 5 is viewed from the front is not limited to a specific configuration. For example, the multiple through openings 19 may be circular, or may be elongated in a direction along an imaginary straight line L1 connecting the fixing hole 17 and the nearest corner 5a among the multiple corners 5a, as in the example shown in FIG. 5. Chips generated when cutting a workpiece using the upper cutting edge 13 tend to flow along the top surface 5. When the multiple through openings 19 have an elongated shape as described above, the chips are less likely to get caught in the multiple through openings 19. In other words, the chips are less likely to clog, and chip discharge is improved.

As shown in the example in FIG. 6, the multiple through openings 19 have a first end 19a located closest to the fixing hole 17, and a second end 19b located farthest from the fixing hole 17. In FIG. 6, the first end 19a and the second end 19b are indicated by dots. Here, the length in the direction perpendicular to the imaginary straight line L2 connecting the first end 19a and the second end 19b is defined as the width W of the multiple through openings 19. The width W of the multiple through openings 19 may have a maximum value closer to the second end 19b than to the first end 19a.

When the multiple through openings 19 have the above configuration, the intervals between the gripping members inserted into each through opening 19 can be narrowed. This makes it easier to increase the gripping force of the multiple gripping members, so the insert 1 can be stably gripped by the multiple gripping members. In the example shown in Figures 5 and 6, the virtual straight lines L1 and L2 are the same.

The size of the insert 1 is not particularly limited. For example, the maximum width of the upper surface 5 may be set to approximately 3 to 20 mm. Also, the height from the upper surface 5 to the lower surface 7 may be set to approximately 5 to 20 mm.

The material of the insert 1 may be, for example, a cemented carbide or a cermet. The composition of the cemented carbide may be, for example, WC-Co, WC-TiC-Co, or WC-TiC-TaC-Co. Here, WC, TiC, and TaC are hard particles, and Co is the binder phase.

Cermets are sintered composite materials in which ceramic components are combined with metals. One example of a cermet is a titanium compound whose main component is titanium carbide (TiC) or titanium nitride (TiN). However, it goes without saying that the material of the insert 1 is not limited to the above composition.

The surface of the insert 1 may be coated with a coating by chemical vapor deposition (CVD) or physical vapor deposition ( _PVD ) techniques, with coating compositions including titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina ( _Al2O3 ).

<Method of manufacturing machined product>
Next, a non-limiting method for manufacturing a machined product having one surface according to the present disclosure will be described with reference to Figs. 9 to 11. Figs. 9 to 11 show a method for manufacturing a machined product 201 when cutting is performed using the above-mentioned cutting tool 101. In Figs. 9 to 11, a rotation axis O1 of the cutting tool 101 is indicated by a two-dot chain line. The machined product 201 is produced by cutting a workpiece 203.

The manufacturing method of the machined product 201 may include the following steps:
(1) rotating a cutting tool 101 as typified by the above-described embodiment;
(2) contacting a rotating cutting tool 101 with a workpiece 203;
(3) removing the cutting tool 101 from the workpiece 203;
The present invention may also include:

Specifically, first, as shown in FIG. 9, the cutting tool 101 may be rotated in the Y1 direction around the rotation axis O1 while being brought relatively close to the workpiece 203. Next, as shown in FIG. 10, the cutting edge 11 of the cutting tool 101 may be brought into contact with the workpiece 203 to cut the workpiece 203. Then, as shown in FIG. 11, the cutting tool 101 may be moved relatively away from the workpiece 203.

The workpiece 203 may be fixed and the cutting tool 101 may be brought closer. Also, as in the example shown in Figures 9 to 11, the workpiece 203 may be fixed and the cutting tool 101 may be rotated around the rotation axis O1. Also, as in the example shown in Figure 11, the workpiece 203 may be fixed and the cutting tool 101 may be moved away. In the example shown in Figures 9 to 11, the workpiece 203 is fixed and the cutting tool 101 is moved in each process, but of course this is not limited to this form.

For example, in step (1), the workpiece 203 may be brought closer to the cutting tool 101. Also, in step (3), the workpiece 203 may be moved away from the cutting tool 101. To continue cutting, the cutting tool 101 may be kept rotating and the process of contacting the cutting edge 11 of the insert 1 with different locations on the workpiece 203 may be repeated.

Typical examples of materials for the workpiece 203 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

This 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 this disclosure.

1 Insert 3 Main body 5 Top surface 5a Corner 5b Side 7 Bottom surface 9 Side surface 11 Cutting edge 13 Upper cutting edge 15 Lower cutting edge 17 Fixing hole 19 Through opening 19a First end 19b Second end 21 First opening 23 2 opening 101 Cutting tool 103 Holder 103a First end 103b Second end 105 Pocket 107 Fixing member 201 Cutting workpiece 203 Work material

Claims (9)

A main body that is detachably attached to the holder;
The body includes:
The top surface and
a lower surface opposite the upper surface;
A side surface connected to the upper surface and the lower surface;
a cutting edge located at an intersection of the top surface and the side surface;
a fixing hole that opens on the upper surface and the lower surface and into which a fixing member for fixing the main body to the holder can be inserted;
a plurality of through openings opening at the upper surface and the lower surface and positioned away from the fastening hole. The plurality of through openings include a first opening and a second opening,
The cutting insert according to claim 1 , wherein when the top surface is viewed from the front, the first opening and the second opening are positioned rotationally symmetric with respect to the fixing hole. The upper surface has a polygonal shape having a plurality of corners,
The fixing hole opens at the center of the upper surface,
The cutting insert according to claim 1 or 2, wherein each of the plurality of through openings is located between the fixing hole and the corner portion. The cutting insert according to claim 3, wherein each of the plurality of through openings is located closer to the fixing hole than the corner portion. The cutting insert according to claim 3 or 4, wherein each of the plurality of through openings has an elongated shape in a direction along an imaginary straight line connecting the fixing hole and the nearest corner among the plurality of corners when the top surface is viewed from the front. When the upper surface is viewed from the front,
Each of the plurality of through openings comprises:
a first end located closest to the fastening hole;
a second end located furthest from the fastening hole;
A length in a direction perpendicular to a virtual line connecting the first end and the second end is a width of each of the through openings,
The cutting insert according to claim 1 , wherein a width of each of the through openings has a maximum value closer to the second end than to the first end. The cutting insert according to any one of claims 1 to 6, wherein the inner diameter of each of the plurality of through openings is smaller than the inner diameter of the fixing hole. a holder having a cylindrical shape extending from a first end to a second end along a rotation axis and having a pocket located on the first end side;
and a cutting insert according to claim 1 located in the pocket. Rotating the cutting tool of claim 8;
contacting the rotating cutting tool with a workpiece;
and removing the cutting tool from the workpiece.

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