Cutting tool and method of manufacturing a machined product

Abstract

A cutting tool (1), comprising: a holder (2) which has a shape extending from a first end (2a) to a second end (2b), and a cutting insert (3) which is arranged on one side of the first end (2a) of the holder (2), wherein the cutting insert (3) has a first surface (31) which has a corner (311) and a first side (312) which extends from the corner (311) towards a side of the second end (2b), a second area (32) adjacent to the first area (31) and a cutting edge (33) which is arranged on at least part of the corner (311) and the first side (312) on a comb part (34) on which the first surface (31) cuts the second surface (32), the holder (2) has a flow path (4) which has a first flow path (41) which has a first outflow outlet (61), is arranged above the cutting insert (3) and extends along a first central axis (S1), and a second flow path (42) which has a second outflow outlet (62), is arranged above the cutting insert (3) and extends along a second central axis (S2), a line which is obtained by extending a first central axis (S1) starting from the first outlet (61) towards the outside of the holder (2), is referred to as a first virtual line (X1), and a line which is obtained by extending the second central axis (S2) starting from the second outlet (62) towards the outside of the holder (2), is referred to as a second virtual line (X2), the first virtual line (X1) is inclined downwards, as it moves away from the first outlet (61), the second virtual line (X2) is inclined downwards, as it moves away from the second outlet (62), a tilt angle of the first virtual line (X1) relative to the first surface (31) is designated as a first angle (Θ1) and a tilt angle of the second virtual line (X2) relative to the first surface (31) is designated as a second angle (Θ2), the first angle (Θ1) is equal to the second angle (Θ2), in a top view an interface of the first virtual line (X1) and the second virtual line (X2) is arranged outside the cutting insert (3), the first virtual line (X1) intersects the corner (311) or the first side (312) and the second virtual line (X2) intersects the first side (312) on a side closer to the second end (2b) than the first virtual line (X1), and in a top view, a distance L1 starting from the first outlet (61) to an interface of the first virtual line (X1) and the comb part (34) is smaller than a distance L2 starting from the second outlet (62) to an interface of the second virtual line (X2) and the comb part (34).

Description

Technical area

[0001] The present disclosure relates to a cutting tool and a method of manufacturing a machined product. background

[0002] As a cutting tool for use in cutting a workpiece such as metal, a cutting tool described in Japanese Unexamined Patent Publication No. 6-254705 (Patent Document 1) is known. The cutting tool described in Patent Document 1 includes a tool body (holder) and a cutting insert, and is applicable to a turning operation such as outer diameter machining.

[0003] The cutting tool described in Patent Document 1 has a plurality of spray outlets. At least one of the plurality of spray outlets is directed toward a front side of a chip, and at least one of the remaining spray outlets is directed toward a rear side of the chip. The chip can be cooled by a cooling liquid (coolant) sprayed from the spray outlet.

[0004] In cases where the coolant is sprayed from both the front and back sides of the chip, stable chip winding may be hindered depending on individual spray angles. In particular, the chip moves rapidly and becomes unstable based on a chip generation point, and tangling or coiling may occur because the coolant sprayed from the spray outlet to the back side of the chip reaches the chip after its generation.

[0005] For example, EP 3 199 273 A1 discloses a cutting tool comprising: a holder extending from a first end to a second end, and a cutting insert arranged on one side of the first end of the holder. The cutting insert has a first surface having a corner and a first side extending from the corner toward one side of the second end, a second surface adjacent to the first surface, and a cutting edge arranged on at least part of the corner and the first side at a ridge portion at which the first surface intersects the second surface.The holder has a flow path including a first flow path having a first outflow outlet, disposed above the cutting insert, and extending along a first central axis, and a second flow path having a second outflow outlet, disposed above the cutting insert, and extending along a second central axis. A line obtained by extending a first central axis from the first outflow outlet toward the outside of the holder is referred to as a first virtual line, and a line obtained by extending the second central axis from the second outflow outlet toward the outside of the holder is referred to as a second virtual line.The first virtual line is inclined downward as it moves away from the first exhaust outlet, the second virtual line is inclined downward as it moves away from the second exhaust outlet, an inclination angle of the first virtual line relative to the first surface is referred to as a first angle and an inclination angle of the second virtual line relative to the first surface is referred to as a second angle, the first angle is equal to the second angle, in a plan view, an intersection of the first virtual line and the second virtual line is located outside the cutting insert, the first virtual line intersects the corner or the first side, and the second virtual line intersects the first side at a side closer to the second end than the first virtual line.

[0006] It is an object of the present invention to further improve cutting tools with regard to their cutting performance. Brief explanation

[0007] The object is achieved by a cutting tool having the features according to claim 1, 2 or 3. The object is further achieved by a method of producing a machined product having the features of claim 11. Further embodiments of the cutting tools are described in the dependent claims. Short description of the drawings Fig. 1 is a side view showing a cutting tool in one of the embodiments of the present disclosure, Fig. Fig. 2 is a side view showing a state in which a flow path or the like in the cutting tool shown in the Fig. 1 is shown translucent, Fig. 3 is an enlarged view on one side of the first end of the cutting tool shown in the Fig. 2 is shown, Fig. 4 is a plan view of the cutting tool used in the Fig. 1 is shown, Fig. Figure 5 is an enlarged view on one side of the first end of the cutting tool shown in the Fig. 4 is shown, Fig. Figure 6 is an enlarged view on one side of the first end of the cutting tool shown in the Fig. 4 is shown, Fig. Figure 7 is an enlarged view on one side of the first end of the cutting tool shown in the Fig. 4 is shown, Fig. Fig. 8 is an enlarged sectional view taken along the line AA in a state obtained by removing the cutting insert in the Fig. 6, Fig. Fig. 9 is an enlarged sectional view taken along the line BB in a state obtained by removing the cutting insert in the Fig. 6, Fig. 10 is a front view showing, in an enlarged manner, the first end of the cutting tool used in the Fig. 1 is shown, Fig. 11 is an enlarged view on one side of the first end of the cutting tool shown in the Fig. 2 is shown, Fig. 12 is a schematic diagram showing a step in the method of manufacturing a machined product in one of the embodiments of the present disclosure, Fig. 13 is a schematic diagram showing a step in the method of manufacturing a machined product in one of the embodiments of the present disclosure, and Fig. 14 is a schematic diagram showing a step in the method of manufacturing a machined product in one of the embodiments of the present disclosure. EmbodimentsCutting tools

[0008] The cutting tools in various embodiments of the present disclosure are described below in detail with reference to the drawings. For descriptive purposes, each of the following referenced drawings shows, in a simplified form, only major elements necessary for describing the embodiments. Therefore, the cutting tools of the present disclosure may include any structural elements not shown in the referenced drawings. Dimensions of the elements in each of the drawings are not those that faithfully show dimensions of actual structural elements and dimensional relationships of these elements. These points also apply to a method of manufacturing a machined product, which will be described later.

[0009] As it is in the Fig. As shown in Figure 1, the cutting tool 1 in one embodiment is a tool for use in a turning operation. The cutting tool 1 comprises a holder 2 and a cutting insert 3 (hereinafter also referred to as an "insert 3").

[0010] The holder 2 has a shape that extends from a first end 2a to a second end 2b. In other words, the holder 2 has a columnar shape. The holder 2 in one of the embodiments has a quadrangular, prismatic shape. The term "quadrilateral, prismatic shape" is a concept that encompasses not only a strictly quadrangular, prismatic shape, but also those with slight irregularities or curvatures. The shape of the holder 2 is not limited to the quadrangular, prismatic shape.

[0011] The holder 2 in the embodiment has a head 21 located on one side of the first end 2a and a shank 22 located on one side of the second end 2b. The head 21 is a portion that allows the insert 3 to be attached. The shank 22 is a portion designed to be held by a machine tool.

[0012] The holder 2 has a pocket 23 which is arranged on one side of the first end 2a in one of the embodiments, as shown in the Fig. 3 and Fig. 10. The pocket 23 corresponds to a portion where the insert 3 is arranged, which is a recessed portion in the head 21. Specifically, the pocket 23 is provided recessed to be open in an upper surface 27, an end surface 28 on one side of the first end 2a, and a side surface 29 in the holder 2 in one of the embodiments. The pocket 23 has a screw hole 231 that can engage with a screw 7 described later. The term "the upper surface 27" is used for the purpose of simplicity and does not denote an up-down direction. For example, the upper surface 27 does not have to be a surface that faces upward when the cutting tool 1 is used. This also applies to a lower surface 26, which will be described later.

[0013] For example, steel, cast iron and an aluminum alloy can be used as a material for the holder 2.

[0014] Dimensions of the holder 2 can be adjusted to the following values. A length of the holder 2 in a direction parallel to a longitudinal direction “a” of the holder 2, which is in the Fig. 1 is, for example, 60 to 200 mm. A width of the holder 2 in a direction perpendicular to the longitudinal direction "a" is, for example, 6 to 50 mm.

[0015] The insert 3 is arranged on one side of the first end 2a of the holder 2. The insert 3 has, in one of the embodiments, a plate shape and has a first surface 31, a second surface 32 and a cutting edge 33, as shown in the Fig. 3 and Fig. 7 is shown.

[0016] At least a portion of the first surface 31 is capable of acting as a chip surface along which chips flow during a cutting operation. The first surface 31 has a corner 311 and a first side 312 extending from the corner 311 toward one side of the second end 2b. Alternatively, the first surface 31 may further have a second side 313 extending from the corner 311.

[0017] The first surface 31 has a quadrilateral shape in one of the embodiments. Specifically, in one of the embodiments, the first surface 31 has an approximately rhombus shape, one side of which is the first side 312. The first side 312 has the same length as the second side 313. The term "quadrilateral shape" does not have to refer to a strict quadrilateral shape, as long as it has an approximately quadrilateral shape. The shape of the first surface 31 is not limited to a quadrilateral shape, but can have other shapes. Examples of other shapes include triangles, pentagons, hexagons, and octagons.

[0018] At least a portion of the second surface 32 is capable of acting as a flank surface during the cutting process. In one embodiment, the second surface 32 is connected to the first surface 31. In one embodiment, the second surface 32 is formed from four surface regions corresponding to four sides of the quadrangular first surface 31.

[0019] The cutting edge 33 is arranged on at least one ridge portion 34 where the first surface 31 intersects the second surface 32. In particular, the cutting edge 33 is arranged on at least a part of the corner 311 and the first side 312 on the ridge portion 34. In one embodiment, the cutting edge 33 is arranged on the entire corner 311 and most of the first side 312 in the ridge portion 34. Alternatively, the cutting edge 33 may be further arranged on at least a part of the second side 313 in the ridge portion 34. The insert 3 is arranged on the pocket 23 in a state in which the cutting edge 33 protrudes to one side of the first end 2a of the holder 2.

[0020] The insert 3 in one of the embodiments has a through-hole 35 extending through the insert 3 in a thickness direction thereof. The through-hole 35 is a portion that allows insertion of a fixing member for fixing the insert 3 to the holder 2. The fixing member is a screw 7 in one of the embodiments. That is, the cutting tool 1 has the screw 7 as the fixing member. The insert 2 is fixable to the holder 3 by inserting the screw 7 into the through-hole 35 and into a screw hole 231 of the pocket 23 in this order and by fastening them to each other. The fixing member may be another fixing member instead of the screw 7. Examples of other fixing members include a clamping member. The insert 3 may not have the through-hole 35 depending on a fixing method of the fixing member.

[0021] As a material of the insert 3, for example, cemented carbide and cermet are usable. Examples of cemented carbide include WC-Co, WC-TiC-Co, or WC-TiC-TaC-Co. WC-Co is produced by adding cobalt powder (Co powder) to tungsten carbide (WC), followed by sintering. WC-TiC-Co is produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is produced by adding tantalum carbide (TaC) to WC-TiC-Co. Cermet is a sintered composite material obtainable by combining metal and a ceramic component. Examples of cermets include those mainly formed of a titanium composition, such as titanium carbide (TiC) or titanium nitride (TiN).

[0022] A surface of the insert 3 can be coated with a coating layer. Examples of the composition of the coating layer include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3). For example, chemical vapor deposition (CVD) and physical vapor deposition (PVD) methods can be used as a method for depositing a coating layer.

[0023] The dimensions of the insert 3 can be adjusted to the following values, for example. A length of one side of the square first surface 31 is, for example, 3 to 54 mm. A thickness of the insert 3 is, for example, 1 to 10 mm. The insert 3 can be either a positive type or a negative type.

[0024] As it is in the Fig. 2 and Fig. As shown in Fig. 4, the holder 2 has a flow path 4. The flow path 4 is disposed within the holder 3 and serves as a part that allows a coolant to flow. Examples of the coolant include water-insoluble cutting fluids and water-soluble cutting fluids. Examples of the water-insoluble cutting fluids include oil-based cutting fluids, inert extreme pressure-based cutting fluids, and active extreme pressure-based cutting fluids. Examples of the water-soluble cutting fluids include emulsion types, soluble types, and solution types of cutting fluids. Alternatively, the coolant may be a gas, such as an inert gas, instead of a liquid.

[0025] The flow path 4 has an inlet 5 and an outlet 6.

[0026] The inflow inlet 5 serves as a portion that allows the coolant supplied from the outside to flow into the flow path 4. At least one or a plurality of the inflow inlets 5 are required. If there are a plurality of inflow inlets 5, the inflow inlet 5 to be used can be selectable depending on a machine tool. The inflow inlet 5, for which use is not required, must be closed by a detachable sealing member. The flow path 4 has three inflow inlets 5 in one of the embodiments, that is, a first inflow inlet 51, a second inflow inlet 52, and a third inflow inlet 53. The first inflow inlet 51 is open at an end surface 24 on one side of the second end 2b of the holder 2.The second inlet 52 and the third inlet 53 are open on a side surface 25 of the holder 2 in a sequence starting from a side of the second end 2b. The number of inlet ports 5 is not limited to three. The positions at which the inlet ports 5 are open are not limited to the above-mentioned positions.

[0027] The outflow outlet 6 serves as a section which allows the coolant to flow out towards the insert 3. The flow path 4 has a first outflow outlet 61 and a second outflow outlet 62 as the outflow outlet 6, as shown in the Fig. 3. In particular, the flow path 4 includes a first flow path 41 and a second flow path 42. The first flow path 41 includes the first outflow outlet 61 as the outflow outlet 6. The second flow path 42 includes a second outflow outlet 62 as the outflow outlet 6. The first outflow outlet 61 may be located on one side of the second end 2a, and the second outflow outlet 62 may be located closer to one side of the second end 2b than the first outflow outlet 61.

[0028] The first flow path 41 is arranged above the insert 3. The second flow path 42 is arranged above the insert 3. The expression that “the first flow path 41 and the second flow path 42 are arranged above the insert 3” can be determined, for example, based on the lower surface 26 of the holder 2 or a central axis S of the holder 2, which will be described later. That is, the height can be determined by viewing one side of the insert 3 as an upper side and one side of the lower surface 26 of the holder 2 as a lower side in a direction perpendicular to the above base. Specifically, the fact that, for example, the first flow path 41 and the second flow path 42 are arranged above the insert 3 means that, in a side view of the holder 2, the first flow path 41 and the second flow path 42 are arranged above the insert 3, as shown in the Fig. 3. Determination of the "upper side" and the "lower side", which will be described later, can be performed in the same manner as the above determination.

[0029] In cases where the insert 3 has the through-hole 35, "the upper side" and "the lower side" may be determined based on a central axis of the through-hole 35 instead of the lower surface 26 of the holder 2. Specifically, the direction perpendicular to the lower surface 26 of the holder 2 may be replaced by a direction along the central axis of the through-hole 35. In this case, a direction extending along the central axis and outward from the insert 3 on one side of the first surface 31 may be referred to as "the upper side," and a direction extending along the central axis and outward from the insert 3 on a side opposite to the first surface 31 may be referred to as "the lower side."

[0030] The first flow path 41 extends along a first central axis S1. The second flow path 42 extends along a second central axis S2. The first central axis S1 can be obtained by, for example, considering that a center of an inner diameter is continuous on a side of the first outflow outlet 61 of the first flow path 41. Similarly, the second central axis S2 can be obtained by, for example, considering that a center of an inner diameter is continuous on a side of the second outflow outlet 62 of the second flow path 42. Both the first outflow outlet 61 side of the first flow path 41 and the second outflow outlet 62 side of the second flow path 42 extend in a rectilinear shape. In one of the embodiments, the first flow path 41 and the second flow path 42 extend in the rectilinear shape as a whole.

[0031] A line obtainable by extending outwardly the first central axis S1 of the holder 2 from the first discharge outlet 61 is referred to as a first virtual line X1, as shown in the Fig. 8. A line obtained by extending outwardly the second central axis S2 of the holder 2 from the second discharge outlet 62 is referred to as a second virtual line X2, as shown in the Fig. 9. The first virtual line X1 corresponds to a flow direction of the fluid flowing out of the first outflow outlet 61. Similarly, the second virtual line X2 corresponds to a flow direction of the fluid flowing out of the second outflow outlet 62.

[0032] The first virtual line X1 is inclined downwards as it moves away from the first discharge outlet 61, as shown in the Fig. 8. The second virtual line X2 is inclined downward as it moves away from the second discharge outlet 62, as shown in the Fig. 9. In other words, the first virtual line X1 and the second virtual line X2 are inclined toward the insert 3 as they move away from their respective exhaust outlets 61 and 62.

[0033] A first angle Θ1 is equal to a second angle Θ2 in the case that the first angle Θ1 is an inclination angle of the first virtual line X1 relative to the first surface 31 and the second angle Θ2 is an inclination angle of the second virtual line X2 relative to the first surface 31, as shown in Fig. 8 and Fig. 9. The first angle Θ1 must be substantially equal to the second angle Θ2. There may be a slight difference between the two angles. In particular, there may be a difference of, for example, ±3° between the two angles. The first angle Θ1 and the second angle Θ2 are, for example, 5 to 30°. The first angle Θ1 and the second angle Θ2 can be determined, for example, based on an arbitrary line Y parallel to the lower surface 26 of the holder 2 or the central axis S of the holder 2. For the purpose of easy determination, the dimensions of the first angle Θ1 and the second angle Θ2 are determined in a front view, as shown in the Fig. 10 is shown.

[0034] As it is in the Fig. 5, in a plan view, an interface P of the first virtual line X1 and the second virtual line X2 is arranged outside the insert 3.

[0035] As it is in the Fig. 6, in a plan view, the first virtual line X1 intersects the corner 311 or the first side 312. In one embodiment, the first virtual line X1 intersects the first side 312. The second virtual line X2 intersects the first side 312 at a side closer to the second end 2b than the first virtual line X1.

[0036] With the above configuration, the following effects can be obtained. In the above configuration, two coolant injections are designed not to interfere with the insert 3 because the interface P is located outside the insert 3, and the two coolant injections have identical spray angles because the first angle Θ1 is the same as the second angle Θ2. This configuration ensures that the two coolant injections individually come into direct contact with the chips at the same angle. Therefore, generated chips can stably spiral through the two coolant injections, resulting in good chip discharge performance. The cutting tool 1 is thus capable of both good chip discharge performance and good cooling effect.

[0037] As it is in the Fig. As shown in Figure 6, a distance L1 from the first discharge outlet 61 to the intersection P1 of the first virtual line X1 with the comb part 34 may be smaller than a distance L2 from the second discharge outlet 62 to an intersection P2 of the second virtual line X2 with the comb part 34. When this configuration is satisfied, the distance L1, which concerns supplying a coolant to the vicinity of the corner 311, is relatively small, and the distance L2, which concerns supplying the coolant to the first side 312, is relatively large. With this configuration, it is possible to increase the accuracy of spraying near the corner 311 (low and medium cutting depth), and it is also possible to distribute the coolant to the first side 312 (medium and larger cutting depth). This results in a good cooling effect under a wide range of cutting conditions. The distance L1 is, for example, 3 to 30 mm. The distance L2 is, for example, 4 to 31 mm.

[0038] The first discharge outlet 61 and the second discharge outlet 62 may be arranged closer to a side of the first end 2a than an end portion 36 on a side of the second end 2b in the insert 3. When this configuration is satisfied, the distances L1 and L2 are smaller, resulting in improvements in chip discharge performance and cooling effect.

[0039] A height of the first discharge outlet 61 from the first surface 31 may be equal to a height of the second discharge outlet 62 from the first surface 31. When this configuration is satisfied, the spray heights of the two coolant injections can be equal. This, together with the fact that the first angle Θ1 is equal to the second angle Θ2, ensures that the two coolant injections contact the chips at an identical height position and at an identical angle. It is therefore possible to stably wind the chips generated by the two coolant injections, resulting in good chip discharge performance. The heights of the first discharge outlet 61 and the second discharge outlet 62 must be substantially the same. There may be a slight difference between the two heights. In particular, a difference of ±3 millimeters between the two heights may exist.

[0040] The height of the first outflow outlet 61 and the height of the second outflow outlet 62 can be determined, for example, based on the bottom surface 26 of the holder 2 or the central axis S of the holder 2. In particular, in one of the embodiments, the holder 2 has the flat bottom surface 26. With this configuration, dimensions from the bottom surface 26 of the holder 2 to a center of the first outflow outlet 61 and a center of the second outflow outlet 62 can be determined as heights of the first outflow outlet 61 and the second outflow outlet 62, respectively. When the central axis S of the holder 2 is used as a level, dimensions from the central axis S of the holder 2 to the centers of the first outflow outlet 61 and the second outflow outlet 62 can be determined as heights of the first outflow outlet 61 and the second outflow outlet 62, respectively.In one of the embodiments, the central axis S of the holder 2 is a central axis of the shaft 22. The central axis of the shaft 22 is an axis which extends to both ends of the shaft in a direction parallel to the longitudinal direction “a” of the holder 2.

[0041] As it is in the Fig. As shown in Fig. 7, in a plan view, a straight line X4 connecting the first discharge outlet 61 and the second discharge outlet 62 may be parallel to the first side 312. When this configuration is satisfied, the first discharge outlet 61 and the second discharge outlet 62 are arranged parallel to the first side 312, on which a part of the cutting edge 33 is located. Therefore, it is possible to effectively inject the coolant into chips at equal angles from the first flow path 41 and the second flow path 42. Therefore, the chips can be stably curved to improve chip discharge performance.

[0042] The straight line X4 is a straight line passing through the centers of the first exhaust outlet 61 and the second exhaust outlet 62. The straight line X4 may be substantially parallel to the first side 312. For example, the straight line X4 may have an error of approximately ±3° relative to the first side 312.

[0043] A flow velocity in the second discharge outlet 62 may be larger than a flow velocity in the first discharge outlet 61. When this configuration is satisfied, a flow velocity of the coolant injected from the second discharge outlet 62 becomes relatively large, which is intended to disperse the coolant near the first side 312. This contributes to improving the effect of stably bringing the coolant injected, which are respectively injected from the first discharge outlet 61 and the second discharge outlet 62, into contact with the chips, thereby improving the chip discharge efficiency.

[0044] The flow velocity in the first outflow outlet 61 denotes a velocity of a fluid flowing from the first outflow outlet 61. Similarly, the flow velocity in the second outflow outlet 62 denotes a velocity of a fluid flowing from the second outflow outlet 62. Specifically, for example, the flow velocity in the first outflow outlet 61 denotes an exit velocity of the fluid flowing from the first outflow outlet 61, and the flow velocity in the second outflow outlet 62 denotes an exit velocity of the fluid flowing from the second outflow outlet 62. The flow velocity in the first outflow outlet 61 is, for example, 20 to 40 m / s. The flow velocity in the second outflow outlet 62 is, for example, 30 to 50 m / s.Flow velocity adjustments can be made, for example, by adjusting a pressure loss in each of the first flow path 41 and the second flow path 42.

[0045] As it is in the Fig. 6, in a plan view, a third angle Θ3 formed by the first virtual line X1 and the first side 312 may be larger than a fourth angle Θ4 formed by the second virtual line X2 and the first side 312. When this configuration is satisfied, there is an arrangement such that the coolant splashes from the second discharge outlet 62, which is located on a side closer to the second end 2b than the first discharge outlet 61, go to one side of the first end 2a relatively. This makes it easier for the generated chips to be pushed away from one side of the first end 2a. This leads to a further improvement in chip discharge performance. The third angle Θ3 is, for example, 16 to 86°. The fourth angle Θ4 is, for example, 15 to 85°.

[0046] As it is in the Fig. 5, in a plan view, a fifth angle Θ5 formed by the first virtual line X1 and the second virtual line X2 may be smaller than each of the third angle Θ3 and the fourth angle Θ4. When this configuration is satisfied, there is a small balance between a force to push the chips outward by the coolant splashing from the first discharge outlet 61 and a force to push the chips outward by the coolant splashing from the second discharge outlet 62. It is therefore possible to efficiently push the generated chips toward one side of the first end 2a. The fifth angle Θ5 is, for example, 1 to 15°.

[0047] As it is in the Fig. 7, a third virtual line X3 may intersect the second side 313 when the third virtual line X3 is a line obtained by extending an inner edge 411 on one side of the first end 2a in the first flow path 41 from the first discharge outlet 61 toward the outside of the holder 2. When this configuration is satisfied, it is possible to inject the coolant to chips generated near the corner 311 on one side of the second side 313.

[0048] In one of the embodiments, the flow path 4 further comprises a third flow path 43, a fourth flow path 44 and a fifth flow path 45, as shown in the Fig. 3. The third flow path 43 is connected to the first flow path 41 and extends downwards from the first flow path 41. The fourth flow path 44 is connected to the second flow path 42 and extends downwards from the second flow path 42. The fifth flow path 45 is connected to the inlet 5 and extends from one side of the second end 2b towards one side of the first end 2a, as shown in the Fig. 2 and Fig. 4. The third flow path 43 is connected to the fifth flow path 45, and the fourth flow path 44 is connected to the fifth flow path 45 on a side closer to the second end 2b than the third flow path 43, as shown in the Fig. 3 is shown.

[0049] There is no particular limitation on the shape of the flow path 4 as long as a coolant can flow therethrough. The shape of the flow path 4 in a cross section orthogonal to the flow direction of the coolant is a circular shape in one of the embodiments. An inner diameter of the flow path 4 is, for example, 0.1 to 10 mm. Specifically, an inner diameter of the first flow path 41 is, for example, 0.1 to 2 mm. An inner diameter of the second flow path 42 is, for example, 0.1 to 2 mm. An inner diameter of the third flow path 43 is, for example, 0.5 to 5 mm. An inner diameter of the fourth flow path 44 is, for example, 0.5 to 5 mm. An inner diameter of the fifth flow path 45 is, for example, 1 to 10 mm. The inner diameter of the flow path 4 decreases gradually as it moves from the inflow inlet 5 to the outflow outlet 6 in one of the embodiments.

[0050] The flow path 4 can be formed, for example, by drilling using a drill or the like. A portion of the hole formed by the drilling process that does not serve as the first flow path 4 must be sealed with a sealing element to prevent coolant leakage. Examples of the sealing element include solder, resin, and screw elements.

[0051] As it is in the Fig. 8 and Fig. As shown in Fig. 9, the holder 2 may have a first wall surface 201 perpendicular to the first central axis S1 and in which the first discharge outlet 61 is open, and a second wall surface 202 perpendicular to the second central axis S2 and in which the second discharge outlet 62 is open. When this configuration is satisfied, the fluid is uniformly sprayed along the central axes S1 and S2 and around the central axes S1 and S2 in the discharge outlets 61 and 62, making it easier for the fluid to accurately reach the target positions (the corner 331 of the first side 32). This leads to improvements in chip discharge performance and cooling effect.

[0052] The first wall surface 201 must be substantially perpendicular to the first central axis S1. For example, the first wall surface 201 may have an error of approximately ±2° relative to the first central axis S1. Similarly, the second wall surface 202 must be substantially perpendicular to the second central axis S2. For example, the second wall surface 202 may have an error of approximately ±2° relative to the second central axis S2.

[0053] Alternatively, the holder 2 may have a first surface 203 which is parallel to the first central axis S1 and connected to the first wall surface 201, and a second surface 204 which is parallel to the second central axis S2 and connected to the second wall surface 202, as shown in the Fig. 8 and Fig. 9. When this configuration is satisfied, a path of the fluid discharged from each of the discharge outlets 61 and 62 can be guided in a desired direction, and it becomes easier for the fluid to accurately reach the target position. This thus leads to improvements in chip discharge efficiency and cooling effect.

[0054] The first surface 203 must be substantially parallel to the first central axis S1. For example, the first surface 203 may have an error of approximately ±2° relative to the first central axis S1. Similarly, the second surface 204 must be substantially parallel to the second central axis S2. For example, the second surface 204 may have an error of approximately ±2° relative to the second central axis S2.

[0055] As it is in the Fig. 5, the interface P in an extending direction of the holder 2 (the longitudinal direction "a") of the first virtual line X1 and the second virtual line X2 may be farther away from the second end 2b of the holder 2 than from the first end 2a of the holder 2. When this configuration is satisfied, the generated chips can be easily pushed out to one side of the first end 2a.

[0056] As it is in the Fig. As shown in Fig. 11, the interface P of the first virtual line X1 and the second virtual line X2 may be arranged below the first surface 31. The injected coolant comes into contact with the chips above the insert 3. In cases where the interface P is arranged as described above, even if a flow direction of the chips pushed out from the interface P by the coolant becomes unstable, the chips pushed out from the interface P are less likely to affect the above contact. This leads to an improvement in chip discharge performance. Method of manufacturing a machined product

[0057] Methods of manufacturing a machined product in various embodiments of the present disclosure are described below with reference to the Fig. 12 to 14 described in detail.

[0058] The method of manufacturing the machined product in one of the embodiments comprises the following steps: (1) Rotating a workpiece 100 as shown in Fig. 12 is shown, (2) Bringing the cutting tool 1 into contact with the workpiece 100 which is rotated as shown in the Fig. 13 is shown, and (3) separating the cutting tool 1 from the workpiece 100, as shown in the Fig. 14 is shown.

[0059] In particular, as it is in the Fig. 12, the workpiece 100 is first rotated based on a rotation axis O. Examples of the material of the workpiece 100 include carbon steel, steel alloys, stainless steel, cast iron, and non-ferrous metals.

[0060] Subsequently, the cutting tool 1 is brought relatively close to the workpiece 100, which is rotated by moving the cutting tool 1 in an arrow direction Z1.

[0061] As it is in the Fig. 13, the workpiece 100 is then cut by bringing the cutting edge 33 of the cutting tool 1 into contact with the workpiece 100 while rotating. Here, the workpiece 100 can be cut while causing the coolant to flow out of the first discharge outlet 61 and the second discharge outlet 62.

[0062] Finally, the cutting tool 1 is relatively moved away from the workpiece 100 to obtain a machined workpiece 110 by moving the cutting tool 1 in an arrow direction Z2 as shown in the Fig. 14 is shown,

[0063] With the method of manufacturing a machined product in one of the embodiments, the use of the cutting tool 1 makes it possible to perform a cutting operation under a wide range of cutting conditions. It is therefore possible to obtain a machined product 110 having a highly accurate machined surface.

[0064] Although the machined product 110 can be obtained by moving the cutting tool 1 in one of the embodiments, it is not intended to be limited thereto. For example, in step (1), the workpiece 100 can be brought close to the cutting tool 1. Similarly, in step (3), the workpiece 100 can be moved away from the cutting tool 1. If it is desired to continue the cutting process, it is necessary to repeat the step of bringing the cutting edge 33 into contact with various portions of the workpiece 100 while continuing to rotate the workpiece 100.

[0065] Although the cutting tools 1 and the methods of manufacturing the machined product 110 in the embodiments of the present disclosure have been exemplified above, the present disclosure is not limited to the above embodiments. It is, of course, possible to implement any of them as long as they do not deviate from the scope of the present disclosure.

[0066] For example, even though in the above embodiments the cutting tools 1 are the tools for use in a turning operation, the cutting tools 1 may alternatively be tools for use in a milling operation.

[0067] In the previous embodiments, the first flow path 41 is connected to the third flow path 43, and the second flow path 42 is connected to the fourth flow path 44. In another embodiment, the first flow path 41 and the second flow path 42 may be connected to a single flow path. In other words, the single flow path may be arranged between the fifth flow path 45, the first flow path 41, and the second flow path 42.

[0068] Although the shape of the flow path 4 in the cross section orthogonal to the flow direction of the coolant is the circular shape in the foregoing embodiments, the shape of the flow path 4 in the cross section may alternatively be an elliptical shape.

[0069] The singular forms “a” and “the” include the plural forms thereof throughout the revelation, unless the context clearly indicates otherwise. List of reference symbols 1 cutting tool 2 holders 2a first end 2b second end 21 head 22 shaft 23 Bag 231 screw hole 24 End face 25 a side surface 26 lower surface 27 upper surface 28 End face 29 a side surface 201 first wall surface 202 second wall surface 203 first area 204 second area 4 Flow path 41 first flow path 411 inner edge 42 second flow path 43 third flow path 44 fourth flow path 45 fifth flow path 5 Inlet 51 first inlet 52 second inlet 53 third inlet 6 Outlet 61 first outlet 62 second outlet 3 cutting insert 31 first area 311 Corner 312 first page 313 second page 32 second area 33 Cutting edge 34 Comb part 35 through hole 36 final section 7 screw 100 workpieces 110 machined product S1 first central axis S2 second central axis X1 first virtual line X2 second virtual line X3 third virtual line Θ1 first angle Θ2 second angle Θ3 third angle Θ4 fourth angle Θ5 fifth angle

Claims

[1] A cutting tool (1), comprising: a holder (2) having a shape extending from a first end (2a) to a second end (2b), and a cutting insert (3) which is arranged on one side of the first end (2a) of the holder (2), wherein the cutting insert (3) has a first surface (31) having a corner (311) and a first side (312) extending from the corner (311) towards one side of the second end (2b), a second surface (32) adjacent to the first surface (31) and a cutting edge (33) arranged on at least a part of the corner (311) and the first side (312) on a comb part (34) at which the first surface (31) intersects the second surface (32), the holder (2) has a flow path (4) which has a first flow path (41) having a first outflow outlet (61), arranged above the cutting insert (3) and extending along a first central axis (S1), and a second flow path (42) having a second outflow outlet (62), arranged above the cutting insert (3) and extending along a second central axis (S2), a line obtained by extending a first central axis (S1) from the first outflow outlet (61) towards the outside of the holder (2) is referred to as a first virtual line (X1), and a line obtained by extending the second central axis (S2) from the second outflow outlet (62) towards the outside of the holder (2) is referred to as a second virtual line (X2), the first virtual line (X1) is inclined downwards as it moves away from the first outlet (61), the second virtual line (X2) is inclined downwards as it moves away from the second outlet (62), an inclination angle of the first virtual line (X1) relative to the first surface (31) is referred to as a first angle (Θ1) and an inclination angle of the second virtual line (X2) relative to the first surface (31) is referred to as a second angle (Θ2), the first angle (Θ1) is equal to the second angle (Θ2), in a plan view, an intersection of the first virtual line (X1) and the second virtual line (X2) is arranged outside the cutting insert (3), the first virtual line (X1) intersects the corner (311) or the first side (312) and the second virtual line (X2) intersects the first side (312) on a side closer to the second end (2b) than the first virtual line (X1), and in a plan view, a distance L1 starting from the first outflow outlet (61) to an intersection of the first virtual line (X1) and the comb part (34) is smaller than a distance L2 starting from the second outflow outlet (62) to an intersection of the second virtual line (X2) and the comb part (34). [2] A cutting tool (1) comprising: a holder (2) having a shape extending from a first end (2a) to a second end (2b), and a cutting insert (3) which is arranged on one side of the first end (2a) of the holder (2), wherein the cutting insert (3) has a first surface (31) having a corner (311) and a first side (312) extending from the corner (311) towards one side of the second end (2b), a second surface (32) adjacent to the first surface (31) and a cutting edge (33) arranged on at least a part of the corner (311) and the first side (312) on a comb part (34) at which the first surface (31) intersects the second surface (32), the holder (2) has a flow path (4) which has a first flow path (41) having a first outflow outlet (61), arranged above the cutting insert (3) and extending along a first central axis (S1), and a second flow path (42) having a second outflow outlet (62), arranged above the cutting insert (3) and extending along a second central axis (S2), a line obtained by extending a first central axis (S1) from the first outflow outlet (61) towards the outside of the holder (2) is referred to as a first virtual line (X1), and a line obtained by extending the second central axis (S2) from the second outflow outlet (62) towards the outside of the holder (2) is referred to as a second virtual line (X2), the first virtual line (X1) is inclined downwards as it moves away from the first outlet (61), the second virtual line (X2) is inclined downwards as it moves away from the second outlet (62), an inclination angle of the first virtual line (X1) relative to the first surface (31) is referred to as a first angle (Θ1) and an inclination angle of the second virtual line (X2) relative to the first surface (31) is referred to as a second angle (Θ2), the first angle (Θ1) is equal to the second angle (Θ2), in a plan view, an intersection of the first virtual line (X1) and the second virtual line (X2) is arranged outside the cutting insert (3), the first virtual line (X1) intersects the corner (311) or the first side (312) and the second virtual line (X2) intersects the first side (312) on a side closer to the second end (2b) than the first virtual line (X1), and in a plan view, a straight line connecting the first discharge outlet (61) and the second discharge outlet (62) is parallel to the first side (312). [3] A cutting tool (1) comprising: a holder (2) having a shape extending from a first end (2a) to a second end (2b), and a cutting insert (3) which is arranged on one side of the first end (2a) of the holder (2), wherein the cutting insert (3) has a first surface (31) having a corner (311) and a first side (312) extending from the corner (311) towards one side of the second end (2b), a second surface (32) adjacent to the first surface (31) and a cutting edge (33) arranged on at least a part of the corner (311) and the first side (312) on a comb part (34) at which the first surface (31) intersects the second surface (32), the holder (2) has a flow path (4) which has a first flow path (41) having a first outflow outlet (61), arranged above the cutting insert (3) and extending along a first central axis (S1), and a second flow path (42) having a second outflow outlet (62), arranged above the cutting insert (3) and extending along a second central axis (S2), a line obtained by extending a first central axis (S1) from the first outflow outlet (61) towards the outside of the holder (2) is referred to as a first virtual line (X1), and a line obtained by extending the second central axis (S2) from the second outflow outlet (62) towards the outside of the holder (2) is referred to as a second virtual line (X2), the first virtual line (X1) is inclined downwards as it moves away from the first outlet (61), the second virtual line (X2) is inclined downwards as it moves away from the second outlet (62), an inclination angle of the first virtual line (X1) relative to the first surface (31) is referred to as a first angle (Θ1) and an inclination angle of the second virtual line (X2) relative to the first surface (31) is referred to as a second angle (Θ2), the first angle (Θ1) is equal to the second angle (Θ2), in a plan view, an intersection of the first virtual line (X1) and the second virtual line (X2) is arranged outside the cutting insert (3), the first virtual line (X1) intersects the corner (311) or the first side (312) and the second virtual line (X2) intersects the first side (312) on a side closer to the second end (2b) than the first virtual line (X1), and a flow velocity in the second outlet (62) is greater than a flow velocity in the first outlet (61). [4] The cutting tool (1) according to any one of claims 1 to 3, wherein the first discharge outlet (61) and the second discharge outlet (62) are arranged closer to a side of the first end (2a) than an end portion on a side of the second end (2b) in the cutting insert (3). [5] The cutting tool (1) according to any one of claims 1 to 4, wherein a height of the first discharge outlet (61) from the first surface (31) is equal to a height of the second discharge outlet (62) from the first surface (31). [6] The cutting tool (1) according to any one of claims 1 to 5, wherein in a plan view, a third angle (Θ3) formed by the first virtual line (X1) and the first side (312) is larger than a fourth angle (Θ4) formed by the second virtual line (X2) and the first side (312). [7] The cutting tool (1) according to claim 6, wherein in a plan view, a fifth angle (Θ5) formed by the first virtual line (X1) and the second virtual line (X2) is smaller than each of the third angle (Θ3) and the fourth angle (Θ4). [8] The cutting tool (1) according to any one of claims 1 to 7, wherein the first surface (31) further comprises a second side (313) extending from the corner (311), and, a line obtained by extending an inner edge on one side of the first end (2a) in the first flow path (41) from the first outflow outlet (61) toward the outside of the holder (2) is referred to as a third virtual line (X3), the third virtual line (X3) intersects the second side (313). [9] The cutting tool (1) according to any one of claims 1 to 8, wherein in an extending direction of the holder (2), the intersection of the first virtual line (X1) and the second virtual line (X2) is farther away from the second end (2b) of the holder (2) than the first end (2a) of the holder (2). [10] The cutting tool (1) according to any one of claims 1 to 9, wherein the intersection of the first virtual line (X1) and the second virtual line (X2) is located below the first surface (31). [11] A method of manufacturing a machined product, comprising: Rotating a workpiece (100), Bringing a cutting tool (1) according to any one of claims 1 to 10 into contact with the workpiece (100) which is rotated, and Separating the cutting tool (1) from the workpiece (100).

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