Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
  • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
  • B23B27/16—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B51/00—Tools for drilling machines

Definitions

• Patent Document 1 discloses a cutting tool having two replaceable cutting inserts.
• the first cutting insert has a rake face, a flank face continuous with the rake face, and a bottom surface continuous with the flank face.
• the flank face has four flank face portions.
• a recess is formed at the boundary between each of the four flank face portions and the bottom surface.
• the first pocket has a first side surface connected to the front end surface, a second side surface connected to the front end surface, located radially outward from the first side surface and facing the first side surface, a third side surface located between the first and second side surfaces and the rear end surface in the direction along the axis, and a seating surface with which the bottom surface contacts.
• Fig. 1 is a schematic perspective view showing the configuration of a drilling tool according to a first embodiment.
• Fig. 2 is a schematic plan view showing the configuration of the drilling tool according to the first embodiment.
• the drilling tool 5 has a main body 100, a first cutting insert 10, a second cutting insert 20, a first fastening screw 3, and a second fastening screw 4.
• the first cutting insert 10 is attached to the main body 100 using the first fastening screw 3.
• the second cutting insert 20 is attached to the main body 100 using the second fastening screw 4.
• the first cutting insert 10 is replaceable.
• the second cutting insert 20 is replaceable.
• the drilling tool 5 according to the first embodiment is a cutting edge-indexable drilling tool 5.
• Axis A is parallel to the direction from the rear end face 114 toward the front end face 113.
• the direction from the rear end face 114 toward the front end face 113 is considered to be the forward direction.
• the direction from the front end face 113 toward the rear end face 114 is considered to be the rearward direction.
• the second groove surface 116 is provided between the second cutting insert 20 and the rear end face 114.
• the second groove surface 116 discharges chips cut by the second cutting insert 20.
• a portion of the second cutting insert 20 is located forward of the front end face 113.
• Figure 3 is a schematic plan view showing the configuration of the first cutting insert 10.
• Figure 4 is a schematic perspective view showing the configuration of the first cutting insert 10.
• the first cutting insert 10 has a center cutting edge 17, a first rake face 16, a first flank face 19, and a first bottom surface 15.
• the first rake face 16 is continuous with the first flank face 19.
• the ridge between the first rake face 16 and the first flank face 19 forms the center cutting edge 17.
• the first inscribed circle E1 is inscribed in the central cutting edge 17.
• the diameter of the first inscribed circle E1 is defined as the first diameter D1.
• the first diameter D1 is, for example, 6.9 mm.
• the first diameter D1 may be 5.9 mm or greater and 7.9 mm or less.
• a recess is formed at the boundary between each of the four flank portions and the first bottom surface 15.
• the first recess 31 is formed at the boundary between the first flank portion 11 and the first bottom surface 15.
• the second recess 32 is formed at the boundary between the second flank portion 12 and the first bottom surface 15.
• the third recess 33 is formed at the boundary between the third flank portion 13 and the first bottom surface 15.
• the fourth recess 34 is formed at the boundary between the fourth flank portion 14 and the first bottom surface 15.
• Each of the first recess 31, second recess 32, third recess 33, and fourth recess 34 is spaced apart from the first through hole 18.
• Figure 5 is a schematic plan view showing the configuration of the second cutting insert 20.
• Figure 6 is a schematic perspective view showing the configuration of the second cutting insert 20.
• the second cutting insert 20 has a peripheral cutting edge 27, a second rake face 26, a second flank face 29, and a second bottom surface 25.
• the second rake face 26 is continuous with the second flank face 29.
• the ridge between the second rake face 26 and the second flank face 29 forms the peripheral cutting edge 27.
• the second bottom surface 25 is located opposite the second rake surface 26.
• the second bottom surface 25 is continuous with the second flank surface 29.
• the second cutting insert 20 has a second through hole 28.
• the second through hole 28 passes between the second rake surface 26 and the second bottom surface 25.
• a second fastening screw 4 is disposed in the second through hole 28.
• the second bottom surface 25 When viewed in the direction in which the second through hole 28 passes, the second bottom surface 25 has, for example, a rectangular shape.
• the second cutting insert 20 does not have a recess recessed toward the second through hole 28 at the boundary between the second bottom surface 25 and the second flank surface 29.
• the second inscribed circle E2 is inscribed in the peripheral cutting edge 27.
• the diameter of the second inscribed circle E2 is the second diameter D2.
• the second diameter D2 is, for example, 6.3 mm.
• the second diameter D2 may be 5.3 mm or greater and 7.3 mm or less.
• the third side surface 43 faces forward. In the direction along the axis A, the third side surface 43 is located between each of the first side surface 41 and the second side surface 42 and the rear end surface 114. From another perspective, in the direction along the axis A, the third side surface 43 is located between the front end surface 113 and the first groove surface 115.
• the first curved surface 45 connects the first side surface 41 and the third side surface 43.
• the second curved surface 46 connects the second side surface 42 and the third side surface 43.
• a first convex portion 51 is formed on the first side surface 41.
• the first convex portion 51 is inserted into a recess provided in the first cutting insert 10.
• a second convex portion 52 is formed on the second side surface 42.
• the second convex portion 52 is inserted into a recess provided in the first cutting insert 10.
• the third side surface 43 does not have a convex portion that fits into the recess provided in the first cutting insert 10. From another perspective, the third side surface 43 is continuous with the first seating surface 44.
• the third side surface 43 may be flat.
• Figure 8 is a schematic plan view showing the configuration of the first pocket 1.
• the plane shown in Figure 8 is parallel to the first seating surface 44 of the first pocket 1.
• first direction 91 the direction from the center of the first convex portion 51 (first center C1) to the center of the second convex portion 52 (second center C2) is defined as the first direction 91.
• the center of a convex portion is defined as the center of the tip of the convex portion.
• the direction parallel to the axis A and from the rear end surface 114 to the front end surface 113 is defined as the second direction 92.
• the angle formed by the first direction 91 and the second direction 92 is defined as the first angle ⁇ 1.
• the first angle ⁇ 1 is greater than 45° and less than 135°.
• the first angle ⁇ 1 is, for example, 82°.
• the first angle ⁇ 1 may be greater than or equal to 70° and less than or equal to 95°.
• the first angle ⁇ 1 may be greater than or equal to 75°, or greater than or equal to 80°.
• the first angle ⁇ 1 may be less than or equal to 90°, or less than or equal to 85°.
• Figure 9 is a schematic cross-sectional view taken along line IX-IX in Figure 8.
• the cross section shown in Figure 9 is along the first direction 91 and perpendicular to the first seating surface 44 of the first pocket 1.
• the first convex portion 51 is located at the boundary between the first side surface 41 and the first seating surface 44.
• the height of the first convex portion 51 relative to the first seating surface 44 is defined as a first height H1.
• the second convex portion 52 is located at the boundary between the second side surface 42 and the first seating surface 44.
• the height of the second convex portion 52 relative to the first seating surface 44 is defined as a second height H2.
• the width of the upper surface of the first convex portion 51 along the first direction 91 is defined as a first width W1.
• the width of the upper surface of the second convex portion 52 along the first direction 91 is defined as a second width W2.
• the value obtained by dividing the first height H1 by the first diameter D1 is, for example, 0.05 or greater and 0.15 or less.
• the value obtained by dividing the first height H1 by the first diameter D1 may be 0.07 or greater, or 0.09 or greater.
• the value obtained by dividing the first height H1 by the first diameter D1 may be 0.13 or less, or 0.11 or less.
• the value obtained by dividing the second height H2 by the first diameter D1 is, for example, 0.05 or greater and 0.15 or less.
• the value obtained by dividing the second height H2 by the first diameter D1 may be 0.07 or greater, or 0.09 or greater.
• the value obtained by dividing the second height H2 by the first diameter D1 may be 0.13 or less, or 0.11 or less.
• the value obtained by dividing the first height H1 by the second diameter D2 is, for example, 0.054 or more and 0.185 or less.
• the value obtained by dividing the first height H1 by the second diameter D2 may be, for example, 0.074 or more, or 0.094 or more.
• the value obtained by dividing the first height H1 by the second diameter D2 may be, for example, 0.165 or less, or 0.145 or less.
• FIG. 12 is a schematic plan view showing the configuration of the main body 100 of the drilling tool 5 according to the second embodiment.
• a third convex portion 53 is formed on the third side surface 43.
• the third convex portion 53 is inserted into the recess of the first cutting insert 10.
• the third convex portion 53 is disposed between the first convex portion 51 and the second convex portion 52.
• the shape of the third convex portion 53 is substantially the same as the shapes of the first convex portion 51 and the second convex portion 52.
• the height of the third convex portion 53 is substantially the same as each of the first height H1 and the second height H2. Note that the height of the third convex portion 53 may be different from each of the first height H1 and the second height H2.
• the drilling tool 5 of this embodiment when viewed along a straight line perpendicular to the first seating surface 44, if the direction from the center of the first convex portion 51 toward the center of the second convex portion 52 is defined as the first direction 91, and the direction parallel to the axis A and from the rear end face 114 toward the front end face 113 is defined as the second direction 92, the angle formed by the first direction 91 and the second direction 92 is greater than 45° and less than 135°.
• the gap between the bottom surface of the second cutting insert 20 and the seating surface of the first pocket 1 will be small. Conversely, if the height of the convex portion is excessively large, the depth of the recess formed in the second cutting insert 20 will need to be increased. If the depth of the recess is large, the area of the flank surface of the second cutting insert 20 will be small, and the contact area between the second cutting insert 20 and the main body portion 100 will be small. In this case, the second cutting insert 20 will not be firmly attached to the main body portion 100.
• a first convex portion 51 is formed on the first side surface 41, and a second convex portion 52 is formed on the second side surface 42. No convex portion is formed on the third side surface 43.
• Sample 2 corresponds to the drilling tool 5 according to the first embodiment. In sample 2, the midpoint between the first convex portion 51 and the second convex portion 52 coincides with the center of the first screw hole 47.
• a first convex portion 51 is formed on the first side surface 41
• a second convex portion 52 is formed on the second side surface 42
• a third convex portion 53 is formed on the third side surface 43.
• Sample 3 corresponds to the drilling tool 5 according to the second embodiment.
• the midpoint between the first convex portion 51 and the second convex portion 52 coincides with the center of the first screw hole 47.
• the second bottom surface 25 of the second cutting insert 20 is substantially parallel to the first seating surface 44.
• the gap between the bottom surface of the second cutting insert 20 and the first seating surface 44 is relatively large. This makes it easier for the operator to visually observe the gap.
• FIG. 14 is a schematic plan view showing a state in which the second cutting insert 20 is placed in the first pocket 1 and pressed against the main body portion 100 in the direction of arrow B. As shown in Fig. 14, the second flank surface 29 of the second cutting insert 20 is pressed against each of the first side surface 41 and the third side surface 43 of the first pocket 1. In this state, the center position of the second through hole 28 of the second cutting insert 20 does not coincide with the center position of the first screw hole 47 provided in the first seating surface 44 of the first pocket 1.
• a first convex portion 51 is formed on the first side surface 41
• a third convex portion 53 is formed on the third side surface 43. Therefore, when the second cutting insert 20 is pressed against the main body portion 100 in the direction of arrow B, the second bottom surface 25 of the second cutting insert 20 comes into contact with each of the first convex portion 51 and the third convex portion 53. Therefore, even if the second cutting insert 20 is mistakenly placed in the first pocket 1, the second cutting insert 20 will be stably placed in the first pocket 1. As a result, it is difficult for an operator to notice that the second cutting insert 20 has been mistakenly attached to the first pocket 1.
• the drilling tool 5 of sample 2 makes it easier for an operator to notice that the second cutting insert 20 has been mistakenly installed in the first pocket 1.
• Table 1 shows the relationship between the height of the convex portion and the second angle ⁇ 2 and the third angle ⁇ 3.
• Table 1 shows the relationship between the height of the convex portion and the second angle ⁇ 2 and the third angle ⁇ 3.
• Table 1 shows the relationship between the height of the convex portion and the second angle ⁇ 2 and the third angle ⁇ 3.
• the second angle ⁇ 2 and the third angle ⁇ 3 each increased.
• the first pocket 1 of the main body 100 of Sample 2 no convex portion is formed on the third side surface 43. Therefore, when a force is applied to the rear of the second cutting insert 20, the second cutting insert 20 tilts rearward. Therefore, if the second cutting insert 20 is mistakenly placed in the first pocket 1, the operator is likely to feel uncomfortable. As a result, the operator is likely to notice that the second cutting insert 20 has been mistakenly installed in the first pocket 1.
• the sum of the second angle ⁇ 2 and the third angle ⁇ 3 in the drilling tool 5 of Sample 2 is greater than the sum of the second angle ⁇ 2 and the third angle ⁇ 3 in the drilling tool 5 of Sample 3. Therefore, compared to the drilling tool 5 of Sample 3, the drilling tool 5 of Sample 2 makes it easier for an operator to notice that the second cutting insert 20 has been erroneously installed in the first pocket 1.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Drilling Tools (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (2)

Citations (6)

• 2024
  • 2024-04-04 JP JP2024551607A patent/JP7589428B1/ja active Active
  • 2024-04-04 WO PCT/JP2024/013905 patent/WO2025210818A1/ja active Pending

Patent Citations (6)

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