The present disclosure relates to a cutting tool and a cutting device. The present application claims the priority benefit of Japanese Patent Application No. 2015-224035 filed on Nov. 16, 2015, the contents of which are incorporated herein by reference in its entirety.
For example, Japanese Patent Laying-Open No. 2015-54385 (PTD 1) discloses a valve finisher capable of coaxially finish machining a hole in a stem guide of a cylinder head in an engine and machining an inner peripheral surface of a valve seat. The valve finisher includes a plurality of cutting inserts which are disposed on the outer periphery of a main body.
PTD 1: Japanese Patent Laying-Open No. 2015-54385
A cutting tool according to one aspect of the present disclosure includes a main body and a cutter. The main body has an outer peripheral surface with one end and the other end. The cutter is fixed to the main body. The main body is provided with a hole extending in a direction from a region surrounded by the one end toward a region surrounded by the other end. When viewed from this direction, the shape of the opening of the hole is circular, and the hole is provided inner than the outer peripheral surface. The cutter has a member disposed inside the hole.
According to the valve finisher, a part of the outer periphery of the main body is cut off so as to form a pocket in the outer periphery, and each cutting insert is disposed in the pocket. Since the outer peripheral portion of the main body is cut off so as to form a pocket therein, the strength and the rigidity of the main body are reduced. Therefore, it is difficult to hold a large number of cutting inserts (cutter) in the main body. As a result, it is necessary to cut a workpiece with a small number of cutters, which consequently deteriorates the durability of cutting edges.
An object of one aspect of the present disclosure is to provide a cutting tool and a cutting device capable of improving the durability of cutters.
According to one aspect of the present disclosure, there is provided a cutting tool and a cutting device capable of improving the durability of cutters.
First, aspects of the present disclosure will be described briefly hereinafter.
(1) A cutting tool 100 according to one aspect of the present disclosure includes a main body 10 and a cutter 20. The main body 10 has an outer peripheral surface 30 with one end 16 and the other end 17. The cutter 20 is fixed to the main body 10.
The main body 10 is provided with a hole 6 extending in a direction from a region 15 surrounded by one end 16 to a region 18 surrounded by the other end 17. When viewed from the above direction, the shape of the opening 19 of the hole 6 is circular, and the hole 6 is provided inner than the outer peripheral surface 30. The cutter 20 has a member disposed inside the hole 6.
After extensive researches for a solution to improve the durability of cutters, the inventors of the present disclosure have achieved the following findings, and thereby established one aspect of the present disclosure. In order to improve the durability of the cutter, it is effective to use a large number of cutters so as to reduce the load of each cutter. In order to use a large number of cutters, it is required to improve the strength of the main body. After extensive studies, the inventors have conceived the idea of providing the cutters inner than the outer peripheral surface of the main body other than on the outer periphery of the main body. As a result, compared with the case where the outer periphery of the main body is cut off to form a pocket, the volume to be cut off the main body is smaller, which makes it possible to improve the strength of the main body.
When a location for disposing the cutter is provided inner than the outer peripheral surface of the main body, it is required to machine the main body in the axial direction instead of in the radial direction. Normally, the shape of a shank for holding a cutting edge is rectangular in plan view. However, in order to form a rectangular hole in the main body along the axial direction in plan view, it is required to perform, for example, electric discharge machining. Compared with machining by a combination of drill machining and subsequent reamer finishing, the electric discharge machining is lower in machining accuracy and longer in machining time, and thereby it is difficult to form a rectangular hole in plan view. Therefore, in the present disclosure, drill machining and subsequent reamer finishing, for example, are used to form a hole having a circular opening in the main body in plan view.
According to the cutting tool 100 according to one aspect of the present disclosure, the shape of the opening 19 of the hole 6 provided in the main body 10 is circular, and the hole 6 is provided inner than the outer peripheral surface 30, which makes it possible to improve the strength of the main body 10. As a result, a large number of cutters 20 can be attached to the main body 10, which makes it possible to improve the durability of each cutter 20.
(2) In the cutting tool 100 according to the above (1), the cutter 20 may include a cutting edge 21 and a shank 22 configured to hold the cutting edge 21. The shank 22 may be disposed inside the hole 6. The cutting edge 21 may be exposed from the hole 6. Thereby, it is possible to improve the durability of the cutting edge 21.
(3) In the cutting tool 100 according to the above (2), when viewed from the above direction, the shank 22 has a first side face 24 which is linear and a second side face 23 which is arc-shaped and provided contiguous to the first face 24. Since the arc-shaped second side face 23 contacts the inner peripheral surface of the hole 6, it is possible to improve the positioning accuracy of the shank 22 in the radial direction, which contributes to the improvement of the cutting accuracy.
(4) The cutting tool 100 according to the above (3) may further include a fastening member 41 configured to fix the shank 22 to the main body 10. The fastening member 41 may be in contact with the first side face 24. As a result, it is possible to suppress the rotation of the shank 22, which makes it possible to firmly fix the shank 22 to the main body 10.
(5) The cutting tool 100 according to the above (3) or (4) may further include a position adjusting member 42 configured to adjust the position of the cutter 20 in the above direction. The shank 22 may include a third side face 25 which is a flat surface inclined with respect to the above direction and provided contiguous to the first side face 24. The position adjusting member 42 may be in contact with the third side face 25. Thereby, it is possible to adjust the position of the cutter 20 in the above direction with high accuracy, which contributes to the improvement of the cutting accuracy.
(6) In the cutting tool 100 according to any one of the above (2) to (5), the shank 22 may have a head portion 221 configured to hold the cutting edge 21 and a root portion 222 opposite to the head portion 221. When viewed from the above direction, the root portion 222 may be completely surrounded by the main body 10. As a result, it is possible to suppress the inclination of the shank 22 with respect to the above direction.
(7) In the cutting tool 100 according to any one of the above (2) to (6), the cutting edge 21 may contact the main body 10, which makes it possible to suppress the vibration of the cutting edge 21 during machining.
(8) The cutting tool 100 according to any one of the above (1) to (7) may further include a reamer 52 provided on the one end side. As a result, it is possible to machine the inner peripheral surface of the valve seat with the cutter 20 while performing finish machining of a hole in the stem guide with the reamer, for example.
(9) In the cutting tool 100 according to any one of the above (1) to (8), the cutter 20 may include six or more cutter members separated from each other. As a result, the resistance to each cutter 20 is reduced, which makes it possible to further improve the durability of the cutters 20.
(10) In the cutting tool 100 according to any one of the above (1) to (9), the cutter 20 may include a first cutter member 20a, a second cutter member 20b and a third cutter member 20c. The first cutter member 20a may include a first cutting edge portion 21a having a first angle θ1, and a first shank portion 22a configured to hold the first cutting edge portion 21a. The second cutter member 20b includes a second cutting edge portion 21b having a second angle θ2 larger than the first angle θ1, and a second shank portion 22b which is configured to hold the second cutting edge portion 21b and is shorter than the first shank portion 22a. The third cutter member 20c includes a third cutting edge portion 21c having a third angle θ3 larger than the second angle θ2, and a third shank portion 22c which is configured to hold the third cutting edge portion 21c and is shorter than the second shank portion 22b. Thereby, it is possible to form an article having an inner peripheral surface whose angle changes along the above direction.
(11) In the cutting tool 100 according to any one of the above (1) to (9), the cutter 20 may include a first cutter member 20a, a second cutter member 20b, and a third cutter member 20c. The first cutter member 20a, the second cutter member 20b and the third cutter member 20c may each have a corresponding cutting edge portion 21a, 21b and 21c. Each cutting edge portion includes a first portion 31 having a first angle θ1, a second portion 32 having a second angle θ2 larger than the first angle θ1, and a third portion 33 having a third angle θ3 larger than the second angle θ2. Thereby, it is possible to form an article having an inner peripheral surface with different angles.
(12) A cutting device 200 according to one aspect of the present disclosure includes the cutting tool 100 according to any one of the above (1) to (9) and a driving unit 57 configured to rotate the cutting tool 100. Thereby, it is possible to provide the cutting device 200 capable of improving the durability of the cutter 20.
Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. It should be noted that in the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.
First, the structure of a cutting tool 100 according to the present embodiment will be described.
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The third main body region 13 is provided contiguous to the second main body region 12. The width of the third main body region 13 increases monotonically in the first direction A. Holes 4 and through holes 5 are provided in the third main body region 13. The fourth main body region 14 is provided contiguous to the third main body region 13. The width W3 of the fourth main body region 14 is constant in the first direction A. As illustrated in
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The fastening member 41 is configured to fix the shank 22 to the main body 10. As illustrated in
The position adjusting member 42 is configured to adjust the position of the cutter 20 in the first direction A. As illustrated in
By adjusting the height of the position adjusting member 42 in the direction along which the hole 4 extends (i.e., the vertical direction in
Each of the plurality of cutter members 20a, 20b and 20c may have a cutting edge portion having a different angle and a shank portion having a different length. Specifically, as illustrated in
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Hereinafter, the structure of the cutting device 200 according to the present embodiment will be described.
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As the main body 10 rotates, the plurality of cutters 20 provided along the circumferential direction of the main body 10 are driven to rotate around the axis line 1. As a result, the inner peripheral surface of the valve seat 53 is machined by the cutting edge 21 of each cutter 20. Similarly, as the reamer 52 held by the reamer holding member 55 is driven to rotate, a hole is machined in the stem guide 58 provided in the cylinder head 54. Since the reamer 52 and the main body 10 are driven to rotate about the same axis line 1, the inner peripheral surface of the valve seat 53 and the hole of the stem guide 58 are machined simultaneously.
Hereinafter, the functions and effects of the cutting tool and the cutting device according to the present embodiment will be described.
According to the cutting tool 100 of the present embodiment, when viewed from the first direction A, the shape of the opening 19 of the hole 6 provided in the main body 10 is circular, and the hole 6 is provided inner than the outer peripheral surface 30, which makes it possible to improve the strength of the main body 10. As a result, a large number of cutters 20 can be attached to the main body 10, which makes it possible to improve the durability of each cutter 20.
According to the cutting tool 100 of the present embodiment, the cutter 20 includes the cutting edge 21 and the shank 22 configured to hold the cutting edge 21. The shank 22 is disposed inside the hole 6. The cutting edge 21 is exposed from the hole 6. Thereby, it is possible to improve the durability of the cutting edge 21.
Moreover, according to the cutting tool 100 of the present embodiment, when viewed from the first direction A, the shank 22 has a first side face 24 which is linear, and a second side face 23 which is arc-shaped and provided contiguous to the first face 24. Since the arc-shaped second side face 23 contacts the inner peripheral surface of the hole 6, it is possible to improve the positioning accuracy of the shank 22 in the radial direction, which contributes to the improvement of the cutting accuracy.
Moreover, according to the cutting tool 100 of the present embodiment, there is further provided a fastening member 41 configured to fix the shank 22 to the main body 10. The fastening member 41 is in contact with the first side face 24. As a result, it is possible to suppress the rotation of the shank 22, which makes it possible to firmly fix the shank 22 to the main body 10.
Moreover, according to the cutting tool 100 of the present embodiment, there is further provided a position adjusting member 42 configured to adjust the position of the cutter 20 in the first direction A. The shank 22 includes a third side face 25 which is a flat surface inclined with respect to the above direction and provided contiguous to the first side face 24. The position adjusting member 42 is in contact with the third side face 25. Thereby, it is possible to adjust the position of the cutter 20 in the above direction with high accuracy, which contributes to the improvement of the cutting accuracy.
Moreover, according to the cutting tool 100 of the present embodiment, the shank 22 has a head portion 221 configured to hold the cutting edge 21 and a root portion 222 opposite to the head portion 221. When viewed from the first direction A, the root portion 222 is completely surrounded by the main body 10. As a result, it is possible to suppress the inclination of the shank 22 with respect to the first direction A.
Moreover, according to the cutting tool 100 of the present embodiment, the cutting edge 21 contacts the main body 10, which makes it possible to suppress the vibration of the cutting edge 21 during machining.
Moreover, according to the cutting tool 100 of the present embodiment, there is further provided a reamer 52 on one end side. As a result, it is possible to machine the inner peripheral surface of the valve seat with the cutter 20 while performing finish machining of a hole in the stem guide with the reamer, for example.
Furthermore, according to the cutting tool 100 of the present embodiment, the cutter 20 includes six or more cutter members separated from each other. As a result, the resistance to each cutter 20 is reduced, which makes it possible to further improve the durability of the cutters 20.
Moreover, according to the cutting tool 100 of the present embodiment, the cutter 20 includes a first cutter member 20a, a second cutter member 20b, and a third cutter member 20c. The first cutter member 20a includes a first cutting edge portion 21a having a first angle θ1, and a first shank portion 22a configured to hold the first cutting edge portion 21a. The second cutter member 20b includes a second cutting edge portion 21b having a second angle θ2 larger than the first angle θ1, and a second shank portion 22b which is configured to hold the second cutting edge portion 21b and is shorter than the first shank portion 22a. The third cutter member 20c includes a third cutting edge portion 21c having a third angle θ3 larger than the second angle θ2, and a third shank portion 22c which is configured to hold the third cutting edge portion 21c and is shorter than the second shank portion 22b. Thereby, it is possible to form an article having an inner peripheral surface whose angle changes along the first direction A.
Furthermore, according to the cutting tool 100 of the present embodiment, the cutter 20 includes a first cutter member 20a, a second cutter member 20b, and a third cutter member 20c. The first cutter member 20a, the second cutter member 20b and the third cutter member 20c each has a corresponding cutting edge portion 21a, 21b and 21c. Each cutting edge portion includes a first portion 31 having a first angle θ1, a second portion 32 having a second angle θ2 larger than the first angle θ1, and a third portion 33 having a third angle θ3 larger than the second angle θ2. Thereby, it is possible to form an article having an inner peripheral surface with different angles.
The cutting device 200 according to the present embodiment includes the cutting tool 100 and a driving unit 57 configured to rotate the cutting tool 100. Thereby, it is possible to provide the cutting device 200 capable of improving the durability of the cutter 20.
It should be understood that the embodiments disclosed herein have been presented for the purpose of illustration and description but not limited in all aspects. It is intended that the scope of the present disclosure is not limited to the description above but defined by the scope of the claims and encompasses all modifications equivalent in meaning and scope to the claims.
1: axis line; 2: recess; 3, 4, 6, 7, 8: hole; 5: through hole; 9: inner peripheral surface; 10: main body; 11: first main body region; 12: second main body region; 13: third main body region; 14: fourth main body region; 15: one region; 16: one end; 17: the other end; 18: the other region; 19: opening; 20: cutter; 20a: first cutter member; 20b: second cutter member; 20c: third cutter member; 21: cutting edge; 21a: first cutting edge portion; 21b: second cutting edge portion; 21c: third cutting edge portion; 22: shank; 22a: first shank portion; 22b: second shank portion; 22c: third shank portion; 23, 23a, 23b, 23c: second side face; 24, 24a, 24b, 24c: first side face; 25: third side face; 30: outer peripheral surface; 31: first section; 32: second section; 33: third section; 35: projection member; 41: fastening member, 42: position adjusting member; 50: connection member; 51: screw; 52: reamer; 53: valve seat; 54: cylinder head; 55: reamer holding member; 56: screw hole; 57: driving unit; 58: stem guide; 59: protrusion; 100: cutting tool; 200: cutting device; 221: head portion; 222: root portion; A: first direction; B: second direction (radial direction); L11, L12, L13, L21, L22, L23: length; W1, W2, W3: width.
Number | Date | Country | Kind |
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2015-224035 | Nov 2015 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2016/080317 | 10/13/2016 | WO | 00 |