The present disclosure relates to a cutting insert, a cutting tool used in machining, and a method for manufacturing a machined product. The cutting tool includes, for example, a rotating tool, a turning tool, and the like. The rotating tool includes, for example, a milling tool, an end mill, and the like.
As a cutting insert used in machining a workpiece made of metal or the like, a cutting insert disclosed in JP 2009-131943 A (Patent Document 1) is known. The cutting insert disclosed in Patent Document 1 includes a second chamfered face as a land face. The width of the second chamfered face is greatest on a bisecting line of a corner portion.
When the cutting insert described in Patent Document 1 is used in machining, of the corner portion thereof, a portion closer to one of adjacent sides tends to have a larger cutting edge angle than a portion positioned on the bisecting line. Therefore, there is a demand to increase the durability of a land face on the portion closer to one of the sides adjacent to the corner portion than the portion positioned on the bisecting line of the corner portion.
A cutting insert according to a non-limiting aspect of the present disclosure includes a first face, a second face, a third face, a virtual central axis, and a virtual reference face. The first face includes a first side, a second side, and a first corner positioned between the first side and the second side. The second face is positioned on an opposite side to the first face. The third face is positioned between the first face and the second face. The central axis is a virtual straight line that passes through a center of the first face and a center of the second face. The reference plane is a virtual plane that is positioned between the first face and the second face and is orthogonal to the central axis.
The first face includes a land face that is connected to the third face and is inclined further away from the reference plane as the land face is away from the third face. The land face includes a first land face connected to the first corner, a second land face connected to the first side, and a third land face connected to the second side. The first land face includes a first region connected to the second land face, and a second region connected to the third land face. Then, a second width of the second region is larger than a first width of the first region in a front view of the first face.
A detailed description will be given below of a cutting insert 1 of an embodiment (hereinafter also simply referred to as the insert 1), with reference to the drawings. However, for ease of explanation, each of the drawings referenced below may be simplified and may illustrate only the main constituent members needed to describe embodiments. Accordingly, the cutting tool disclosed below may be provided with any constituent member that is not illustrated in each of the referenced drawings. Further, the dimensions of the members in the drawings do not faithfully represent the actual dimensions of the constituent members, the dimension ratios of the members, or the like.
The insert 1 may be provided with a first face 3, a second face 5, a third face 7, a virtual central axis S1, and a virtual reference face S2. In a non-limited example illustrated in
The first face 3 may include a first side 9, a second side 11, and a first corner 13. The first corner 13 may be positioned between the first side 9 and the second side 11. In other words, each of the first side 9 and the second side 11 may extend from the first corner 13. As illustrated in
The first face 3 of the non-limited example illustrated in
The second face 5 may be positioned on a side opposite to the first face 3. The second face 5 of the non-limited example illustrated in
Note that the second face 5 may be polygonal in the same manner as the first face 3 but need not necessarily be the same size as the first face 3. For example, the second face 5 may be slightly smaller than the first face 3. Here, the polygonal shape does not strictly mean a shape of a polygon. For example, the four corners of the first face 3 need not necessarily each be a strict angle and may have a slightly rounded shape in a front view of the first face 3.
Also, the four sides need not necessarily be strictly linear in shape. In the non-limited example illustrated in
The third face 7 may be positioned between the first face 3 and the second face 5. The third face 7 may be connected to the first face 3, or another face may be positioned between the first face 3 and the third face 7. Similarly, the third face 7 may be connected to the second face 5, or another face may be positioned between the second face 5 and the third face 7. In the non-limited example illustrated in
A portion of the third face 7 connected to the first side 9 and a portion of the third face 7 connected to the second side 11 may each be flat surfaces. Further, the portion of the third face 7 connected to the first corner 13 may have a convex curved surface shape.
The central axis S1 may be a virtual straight line passing through the center of the first face 3 and the center of the second face 5. The center of the first face 3 can be identified by a center of gravity position of the first face 3 in a plan view, for example. The center of the second face 5 can be identified by a center of gravity position of the second face 5 in a plan view of the second face 5, for example.
The first face 3 and the second face 5 may be orthogonal to the central axis S1 or may be inclined with respect to the central axis S1. The first face 3 may have rotational symmetry with respect to the central axis S1. For example, as illustrated in
The reference plane S2 may be a virtual plane positioned between the first face 3 and the second face 5 and may be orthogonal to the central axis S1. The first face 3 and the second face 5 may be parallel to the reference plane S2 or may be inclined with respect to the reference plane S2. When a direction along the central axis S1 is used as a height, the reference plane S2 may be used as a reference of a position for evaluating the height of each of the portions configuring the first face 3.
The maximum width of the first face 3 in the front view may be from 6 mm to 25 mm, for example. Further, the height from the first face 3 to the second face 5 may be from 1 mm to 10 mm, for example. Here, the height from the first face 3 to the second face 5 may refer to a maximum value of a gap between the first face 3 and the second face 5 in the direction parallel to the central axis S1.
The insert 1 may include a cutting edge 15. The cutting edge 15 may be positioned to include at least a part of a ridge at which the first face 3 and the third face 7 meet. As illustrated in the non-limited example in
The insert 1 may include a through hole 17 that opens in the first face 3. For example, as illustrated in
The through hole 17 can be used to insert a fixing member when fixing the insert 1 to a holder. A screw may be an example of the fixing member. When fixing the insert 1 to the holder, a clamping member may be used instead of the screw, for example. The through hole 17 may be formed from the center of the first face 3 toward the center of the second face 5, but the through hole 17 is not limited to such a configuration. For example, each of regions facing each other in the third face 7 may be open as each opening of the through hole 17.
The first face 3 may include a land face 19. The land face 19 may be a narrow band surface region positioned on a peripheral portion of the first face 3 and may be connected to the third face 7. The land face 19 may be used to increase the strength of the cutting edge 15 positioned on the ridge at which the first face 3 and the third face 7 meet. Thus, the land face 19 may be positioned to include the portion of the ridge described above that is used as the cutting edge 15. The width of the land face 19 may refer to a width in a direction orthogonal to the ridge described above in the front view.
The land face 19 may be inclined further away from the reference plane S2 as the further the land face 19 is away from the third face 7. In other words, in the non-limited example illustrated in
The land face 19 in the non-limited example illustrated in
As illustrated in
The first land face 21 in the non-limited example illustrated in
In the non-limited example illustrated in
In a case where the cutting edge angle of the second portion 13b is larger than the cutting edge angle of the first portion 13a, a large cutting load may be more likely to be applied to the second region 21b than to the first region 21a. In the insert 1, the second width W12 of the first land face 21 in the second region 21b may be larger than the first width W11 of the first land face 21 in the first region 21a, and the durability of the portion to which the relatively large cutting load is likely to be applied may be high. Therefore, the durability of the insert 1 as a whole may be high.
Also, in the insert 1, a width W1 of the first land face 21 may not be large throughout a whole, and the second width W12 of the second region 21b may be relatively large, while the first width W11 of the first region 21a is relatively small. Therefore, it may be easy to avoid an excessive deterioration in cutting performance. As a result, for example, chatter vibration may be easily suppressed.
In this way, the insert 1 can achieve favorable machining both a case where the cutting edge angle of the second portion 13b is larger than the cutting edge angle of the first portion 13a, and a case where the first corner 13 is used as a flat cutting edge.
The first width W11 of the first region 21a and the width second W12 of the second region 21b are not limited to particular values. The first width W11 of the first region 21a can be set from 0.1 mm to 1 mm, for example. The second width W12 of the second region 21b can be set from 0.2 mm to 1.5 mm, for example. A ratio W12/W11 of the first width W11 of the first region 21a and the second width W12 of the second region 21b can be set from 1.1 to 3, for example.
A first inclination angle θ1 of the first region 21a with respect to the reference plane S2 may be the same as a second inclination angle θ2 of the second region 21b with respect to the reference plane S2. In this case, a change in the inclination angle of the first land face 21 may be small. As a result, variations in the strength of the insert 1 in the first land face 21 may be easily suppressed to be small. In addition, chips may tend to flow smoothly during machining.
The first land face 21 may include a third region 21c. The third region 21c in the non-limited example illustrated in
A third width W13 of the third region 21c may be larger than the first width W11 of the first region 21a and smaller than the second width W12 of the second region 21b in the front view. The third width W13 may be a width of the first land face 21 in the third region 21c. In a case where the width W1 of the first land face 21 changes in a stepwise manner as described above, the width W1 of the first land face 21 may be larger in the region where the cutting edge angle is larger. As a result, the durability of the insert 1 as a whole may be even higher while avoiding an excessive deterioration in the cutting performance.
The width W1 of the first land face 21 may increase from the first region 21a toward the second region 21b in the front view. In a case where the width W1 of the first land face 21 changes as described above, the width W1 of the first land face 21 may be larger in the region where the cutting edge angle is larger. As a result, the durability of the insert 1 as a whole may be even higher while avoiding an excessive deterioration in the cutting performance.
In a case where the first land face 21 includes the third region 21c, a third inclination angle θ3 of the third region 21c with respect to the reference face S2 may be the same as the first inclination angle θ1 of the first region 21a. In this case, a change in the inclination angle of the first land face 21 may be small. As a result, variations in the strength of the insert 1 in the first land face 21 may tend to be reduced and easily suppressed. In addition, the chips may tend to flow smoothly during machining.
The second land face 23 may include a fourth region 23a. The fourth region 23a in the non-limited example illustrated in
For example, during a case of machining in which the cutting edge angle of the second portion 13b is larger than the cutting edge angle of the first portion 13a, the large cutting load may be more likely to be applied to the cutting edge 15 positioned on the first corner 13 than to the cutting edge 15 positioned on the first side 9. As such, a relatively large cutting load may be likely to be applied to the fourth region 23a, which is the portion of the second land face 23 positioned near the first land face 21, in comparison to other portions of the second land face 23.
In a case where the fourth width W21 of the fourth region 23a positioned relatively close to the first land face 21 is constant, the load may be easily distributed over a wide range of the second land face 23. Therefore, the durability of the second land face 23 may be high.
The third land face 25 may include a fifth region 25a. The fifth region 25a in the non-limited example illustrated in
For example, if the first corner 13 is used as the flat cutting edge, surface roughness may be small and surface accuracy of the machined surface may be high. If a portion of the first side 9 connected to the fifth region 25a is used as part of the flat cutting edge, cutting resistance of the above-described portion on the first side 9 may be suppressed to be small.
The first face 3 may include a rake face 27. The rake face 27 in the non-limited example illustrated in
The rake face 27 may include a first rake face 29, a second rake face 31, and a third rake face 33. In the non-limited example illustrated in
As illustrated in
During the machining of the workpiece, the flow direction of chips generated at the first corner 13 may be more likely to be unstable than that of the chips generated at the first side 9 and the second side 11. However, if the inclination angle φ1 is larger than the inclination angle φ2 and the inclination angle φ3, the flow direction of the chips generated at the first corner 13 may be easily controlled at the first rake face 29. As a result, the chips may be easily processed in a stable manner.
The first rake face 29 may include a first section 35, a second section 37, and a third section 39. In the non-limited example illustrated in
The third section 39 may be a region positioned on the bisector L3 of the first corner 13. Specifically, the third section 39 in the non-limited example illustrated in
As illustrated in
During the machining of the workpiece, the flow direction of the chips generated at the first corner 13 may be more likely to be unstable than that of the chips generated at the first side 9 and the second side 11. In particular, the flow direction of the chips generated at the center of the first corner 13 positioned on the bisector L3 of the first corner 13 may easily become unstable. However, if the inclination angle φ13 is larger than the inclination angle φ11 and the inclination angle φ12, the direction of flow of the chips generated at the center of the first corner 13 may be easily controlled in the third section 39. As a result, the chips may be easily processed in a stable manner.
The second rake face 31 may include a fourth section 41. The fourth section 41 in the non-limited example illustrated in
During the machining of the workpiece, the flow direction of the chips generated at the first side 9 may be more likely to be stable than that of the chips generated at the first corner 13. In a case where the inclination angle φ4 decrease as the fourth section 41 is away from the first rake face 29, the inclination angle φ2 may be easily made smaller while avoiding abrupt changes in the inclination angle φ1 and the inclination angle φ2. As a result, the flow of chips generated at the first side 9 may tend to be smooth.
The third rake face 33 may include a fifth section 43. The fifth section 43 in the non-limited example illustrated in
During the machining of the workpiece, the flow direction of the chips generated at the second side 11 may be more likely to be stable than that of the chips generated at the first corner 13. In a case where the inclination angle φ5 decrease as the fifth section 43 is away from the first rake face 29, the inclination angle φ3 may be easily made smaller while avoiding abrupt changes in the inclination angle φ1 and the inclination angle φ3. As a result, the flow of the chips generated at the second side 11 may tend to be smooth.
Examples of a material of the insert 1 may include cemented carbide alloy and cermet. Examples of the composition of the cemented carbide alloy may include WC—Co, WC—TiC—Co, and WC—TiC—TaC—Co. Here, WC, TiC, and TaC may be hard particles, and Co may be a binder phase.
In addition, the cermet may be a sintered composite material obtained by combining a metal with a ceramic component. Specifically, examples of the cermet may include titanium compounds in which one of titanium carbide (TiC) and titanium nitride (TiN) is the main component. However, it goes without saying that the material of the insert 1 is not limited to the composition described above.
The surface of the insert 1 may be coated with a coating film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the coating film include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), alumina (Al2O3), and the like.
Next, a cutting tool 101 of a non-limiting embodiment will be described using
The cutting tool 101 may be used for milling processing. The cutting tool 101 may be provided with the holder 103 and the insert 1, as illustrated in
There may be only one of the pockets 105, or as in a non-limited example illustrated in
The pocket 105 may be open to an outer circumferential face of the holder 103 and an end face nearer on the first end 103a. In a case where the holder 103 includes the plurality of pockets 105, these pockets 105 may be positioned at equal intervals or may be positioned at unequal intervals about the rotation axis Y1. As is clear from the fact that the holder 103 includes the pocket 105 and the like, the holder 103 does not have a strictly cylindrical shape.
The insert 1 may be mounted in the pocket 105 such that at least a part of the cutting edge 15 protrudes from the holder 103. Specifically, the insert 1 may be mounted on the holder 103 such that the cutting edge is positioned further to the outside than the outer peripheral surface of the holder 103.
In the cutting tool 101, the second face 5 and the third face 7 of the insert 1 abut the holder 103.
The insert 1 may be mounted in the pocket 105 using the screw 107. Specifically, the screw 107 may be inserted into the through hole 17 in the insert 1, the leading end of the screw 107 may be inserted into a screw hole formed in the pocket 105, and the insert 1 may be mounted on the holder 103 by fixing the screw 107 into the screw hole.
Steel, cast iron, or the like can be used as the holder 103. Among these materials, steel may be used in particular, from the viewpoint of increasing toughness of the holder 103.
Next, a description will be given of a method for manufacturing a machined product according to a non-limiting embodiments with reference to
(1) rotating the cutting tool 101;
(2) bringing the cutting tool 101 that is rotating into contact with the workpiece 201; and
(3) separating the cutting tool 101 from the workpiece 201.
More specifically, first, as illustrated in
The workpiece 201 may be fixed and the cutting tool 101 may be brought close to the workpiece 201. In addition, in
For example, in step (1), the work piece 201 may be brought close to the cutting tool 101. In the same manner, in step (3), the work piece 201 may be moved away from the cutting tool 101. In a case in which the machining is to be continued, steps of bringing the cutting edge 15 of the insert 1 into contact with different locations on the workpiece 201 may be repeated while maintaining the rotating state of the cutting tool 101.
Here, representative examples of the material of the workpiece 201 may include carbon steel, alloy steel, stainless steel, cast iron, non-ferrous metals, and the like.
Number | Date | Country | Kind |
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2018-205561 | Oct 2018 | JP | national |