JP2019055449A - Cutting tools and processing methods - Google Patents

Abstract

An object of the present invention is to reduce the time required to replace a cutting tool and also reduce the time required for drilling and chamfering. A cutting tool 10 has a plurality of carbide tips disposed at a tip 12 of a cylindrical main body 11, and the plurality of carbide tips include at least a hole-drilling tip 15 and a chamfering tip 16, A drilling tip 15 is disposed at the tip 32 of the main body 11, and a chamfering tip 16 is disposed at a position recessed from the tip 12. Chamfering of the corner 3 between the side surface 2b of the bottomed hole 2 drilled by the hole-drilling tip 15 and the top surface 1a of the workpiece 1 is started by the tip 16, and the drilling and chamfering are finished at the same time. Therefore, there is no need to change the cutting tool for drilling to a cutting tool for chamfering when performing chamfering, and the machining time can be reduced because both drilling and chamfering can be performed with one cutting tool 10. Can be shortened. [Selection diagram] Figure 2

Description

  The present invention relates to a cutting tool for processing a workpiece and a processing method for processing a workpiece using the cutting tool.

  For example, as a tool for drilling a workpiece, there is a cutting tool in which cemented carbide tips are arranged at equal intervals in the circumferential direction (see, for example, the following patent document). This cutting tool can increase the cutting force because a plurality of cemented carbide tips are arranged at equal intervals on the same circumference. That is, a hole having a predetermined depth can be formed by drilling a workpiece with a circle having the outermost diameter in which the carbide tip moves circularly.

JP 2012-131027 A

  When drilling a workpiece with the above cutting tool, the angle between the upper surface of the workpiece into which the cemented carbide chip cuts and the inner surface of the drilled hole is formed at right angles. After the drilling process, the cutting tool for drilling is replaced with a cutting tool for chamfering to chamfer the corners. For this reason, it takes time to replace the cutting tool, and the working efficiency is poor. In addition, since the drilling process and the chamfering process are performed separately, there is a problem that the processing time becomes long.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the machining time between the drilling process and the chamfering process while omitting the replacement time of the cutting tool.

  According to the present invention, a cutting tool in which a plurality of carbide tips are disposed at the tip of a cylindrical body and a workpiece are relatively rotated about the axis of the cutting tool and moved relatively in the axial direction. A cutting tool for cutting a workpiece with the cemented carbide chip, wherein the plurality of cemented carbide chips include at least a drilling chip and a chamfering chip, and the drilling hole is formed at the tip of the main body. A chip is disposed, the chamfering chip is disposed at a position retracted from the tip, and the chamfering chip drills the hole with the chamfering chip immediately before the drilling chip is drilled to a predetermined depth. The chamfering process of the corner between the side surface of the hole with the bottom and the upper surface of the workpiece is started, and the drilling process and the chamfering process can be finished simultaneously.

  The present invention is also a method for machining a hole with a bottom using the cutting tool, wherein the cutting tool and the workpiece are moved relative to each other in the axial direction of the cutting tool. Cutting a hole-forming tip, and immediately before the hole-forming tip is drilled to a predetermined depth, the side surface of the bottomed hole and the workpiece to be drilled with the hole-forming chip by the chamfering chip. The chamfering process of the corner with the upper surface is started, and the drilling process and the chamfering process can be finished simultaneously.

  Furthermore, the present invention is a method of machining a hole with a bottom using the cutting tool, wherein the cutting tool and the workpiece are moved relative to each other in the axial direction of the cutting tool. Cutting a hole-forming tip, and immediately before the hole-forming tip is drilled to a predetermined depth, the side surface of the bottomed hole and the workpiece to be drilled with the hole-forming chip by the chamfering chip. A chamfering process of a corner with the upper surface is started, and a first machining process for forming the bottomed hole having the predetermined depth is fixed, and the axial position of the cutting tool is fixed after the first machining process. The cutting tool and the workpiece are moved relatively in a direction perpendicular to the axial direction, and the bottomed hole is made into a long hole and the corner formed at the time of forming the long hole is chamfered. You may make it provide the 2nd processing process chamfered with the chip | tip for a work.

  The cutting tool according to the present invention has a plurality of cemented carbide tips disposed at the tip of a cylindrical main body, and the plurality of cemented carbide tips include at least a drilling tip and a chamfering tip, and a hole is formed at the tip of the main body. An opening tip is arranged, the chamfering tip is arranged at a position retracted from the tip, and the drilling tip is drilled by the chamfering tip with the chamfering tip immediately before drilling a predetermined depth. Chamfering of the corner between the side of the hole with the bottom and the top surface of the workpiece is started, and the drilling and chamfering can be completed at the same time, so when performing chamfering, a cutting tool for drilling There is no need to replace with a chamfering cutting tool. In addition, since it is possible to perform drilling and chamfering with a single cutting tool, the processing time can be shortened.

  Further, the processing method according to the present invention is a method for processing a hole with a bottom using the above cutting tool, and the side surface of the bottomed hole with a chamfering tip immediately before a predetermined depth is drilled with a drilling tip. When the chamfering of the corner between the workpiece and the upper surface of the workpiece is started and a bottomed hole with a predetermined depth is formed in the workpiece, the drilling and chamfering are completed simultaneously with one cutting. Drilling and chamfering can be performed with a tool, and processing time can be shortened.

  Furthermore, the processing method according to the present invention is a method for processing a hole with a bottom using the above cutting tool, wherein the side surface of the hole with the bottom is chamfered by a chamfering tip immediately before a predetermined depth is drilled by a drilling tip. Chamfering of the corner between the workpiece and the upper surface of the workpiece is started, and a bottomed hole formed in the first processing step is formed into a long hole by forming a bottomed hole having a predetermined depth. And the second machining step of chamfering the corners formed when forming the long holes with a chamfering tip, it is possible to efficiently form a long hole with a predetermined depth with one cutting tool, and the processing time Can be shortened.

It is a bottom view which shows the structure of a cutting tool. It is the perspective view which looked at the cutting tool of FIG. 1 from the A direction side. It is a top view which shows the positional relationship of the chip | tip for drilling, and the chip | tip for chamfering. It is a side view which shows the state immediately after the start of drilling. It is a side view which shows the state in which the drilling process advanced and the bottomed hole was formed in the workpiece. It is a side view which shows the state which chamfering was started and the corner | angular of the side surface of a hole with a bottom and the upper surface of a to-be-processed object was chamfered. It is a side view which shows the state which the drilling process and the chamfering process were complete | finished simultaneously. It is the top view and side view which show a 1st process process. It is the top view and side view which show the state immediately after the start of a 2nd process process. It is the top view and side view which show the state which expands a hole with a bottom in a horizontal direction among 2nd processing processes. It is the top view and side view which show the state which made the hole with a bottom into the long hole by the 2nd processing process. It is a bottom view which shows the structure of the modification of a cutting tool. It is the perspective view which looked at the cutting tool of FIG. 12 from the A direction side. It is the perspective view which looked at the cutting tool of FIG. 12 from the B direction side. It is the perspective view which looked at the cutting tool of FIG. 12 from the C direction side. It is a top view which shows the positional relationship of the chip | tip for hole making, the chip | tip for chamfering, and the chip | tip for side shaping. It is a side view which shows immediately after the start of drilling and side shaping. It is a side view which shows the state which the chamfering process was started in parallel with the drilling process and the side surface shaping process, and the angle | corner of the side surface of a hole with a bottom and the upper surface of a workpiece was chamfered. It is a side view which shows the state which the drilling process, the side shaping process, and the chamfering process were complete | finished simultaneously. It is a partially enlarged view showing a state of a side surface shape of a hole with a bottom when drilling is performed only with a chip for drilling. It is a partially expanded view which shows the state of the side surface shape of a hole with a bottom at the time of performing side surface shaping with the side surface shaping chip.

1 First Embodiment [Cutting Tool]
A cutting tool 10 shown in FIG. 1 and FIG. 2 is a cutting tool for cutting a workpiece, and includes a cylindrical main body 11 and a plurality of cemented carbide tips disposed at a distal end 12 of the main body 11. . FIG. 2 shows the main body 11 with the tip 12 facing upward, but in practice, the workpiece is cut with the tip 12 facing downward.

  The plurality of carbide tips include at least a drilling tip 15 and a chamfering tip 16. As shown in FIG. 2, the hole-forming tip 15 is composed of, for example, a cutting blade formed in a rhombus shape, and machining surfaces 150 and 151 for cutting a workpiece in the axial direction to perform a hole-drilling process, and a blade edge 152. And have. The chamfering tip 16 is made of, for example, a rectangular cutting blade, and has a machining surface 160 that performs chamfering to remove the corners between the inner side surface of the hole formed by drilling and the upper surface of the workpiece. have. Note that the shape, size, material, and the like of the punching chip 15 and the chamfering chip 16 are not limited to the configuration shown in the present embodiment.

  The front end 12 of the main body 11 has an end face 12a. The end surface 12 a is recessed near the rotation center 100, which is the axis of the cutting tool 10, and is a surface inclined toward the outside of the main body 11. The tip 12 on the arrow A direction side is formed with a notch 120 for discharging chips of the workpiece. On the rear side of the notch 120 shown in FIG. 2, a pocket 13 formed according to the outer shape of the punching chip 15 is provided. A female screw (not shown) is formed on the side wall 122 connected to the pocket 13. When attaching the drilling tip 15 to the tip 12 of the main body 11, the drilling tip 15 is disposed in the pocket 13, and is screwed into the female screw formed on the side wall 122 by the male screw 17 and fastened. Thus, the hole-forming tip 15 can be fixed to the tip 12.

  A notch 121 is formed on the outer peripheral side of the tip 12 of the main body 11 shown in FIG. The notch 121 is provided with a pocket 14 formed according to the outer shape of the chamfering chip 16. Although not shown, the pocket 14 is connected to a side wall on which a female screw is formed. The chamfering chip 16 can be fixed at a position retracted from the distal end 12 by disposing the chamfering chip 16 in the pocket 14 and screwing and fastening the chamfering chip 16 to the female screw with the male screw 18. In the example of FIG. 2, the position retracted from the tip 12 is a position retracted rearward (downward in the illustrated example) from the position of the machining surface 150 of the punching chip 15 and the end surface 12 a of the tip 12. Therefore, the chamfering tip 16 is positioned at a position where it does not contact the workpiece immediately after the start of drilling by the drilling tip 15. Further, the machining surface 160 of the chamfering tip 16 is inclined obliquely as compared with the machining surface 150 of the drilling tip 15. A motor (not shown) is connected to the main body 11, and the hole-forming chip 15 and the chamfering chip 16 can be circularly moved by rotating the main body 11.

  When the workpiece is cut with the cutting tool 10 to form a hole with a bottom having a predetermined depth, the chamfering tip 16 is formed immediately before the hole with the bottom with a predetermined depth is formed with the drilling tip 15. The chamfering is started by contacting the corner between the inner side surface of the bottomed hole and the upper surface of the workpiece. That is, since the height position of the chamfering tip 16 is lowered as the drilling progresses, the chamfering tip 16 comes into contact with the corner of the machining surface 160 immediately before the bottomed hole reaches a predetermined depth. The chamfering process is started in parallel with the drilling process. When the depth of the hole with the bottom reaches a predetermined depth, the drilling process and the chamfering process can be finished at the same time. Detailed processing operations for forming a bottomed hole having a predetermined depth in the workpiece will be described in a processing method described later. The cutting tool 10 can also form a through-hole penetrating in the thickness direction of the workpiece in addition to the bottomed hole in the workpiece.

  As described above, in the cutting tool 10 according to the present invention, the hole-forming tip 15 and the chamfering tip 16 are respectively disposed at the tip 12 of the main body 11, and the chamfering tip 16 is disposed at a position retracted from the tip 12. Therefore, it is not necessary to replace the cutting tool for drilling with the cutting tool for chamfering when chamfering is performed. In addition, since the drilling process and the chamfering process can be performed with one cutting tool 10, the processing time can be shortened compared to the conventional technique.

[First example of processing method using cutting tool]
Next, a machining method for forming a hole with a bottom in the workpiece 1 shown in FIG. 3 using the cutting tool 10 will be described. The workpiece 1 to be cut is not limited in material, size, thickness and the like. A rotation locus P indicated by a dotted line in the drawing is an area in which the outermost diameter (blade edge 152) of the drilling tip 15 moves circularly when the cutting tool 10 rotates about the rotation center 100 as an axis.

  As shown in FIG. 4, the body 11 is rotated by, for example, an arrow L direction by a motor (not shown), and the drilling chip 15 is cut by, for example, the lifting means 20 while circularly moving along the rotation locus P shown in FIG. By relatively moving the cutting tool 10 in the axial direction (−Z direction) between the tool 10 and the workpiece 1, the machining surface 150 of the drilling tip 15 is cut into the upper surface 1 a of the workpiece 1. The workpiece 1 is drilled in a circular shape.

  As shown in FIG. 5, when the drilling process proceeds by the processing surfaces 150 and 151 of the drilling tip 15, the bottomed hole 2 having the bottom 2 a is formed in the workpiece 1. The bottom 2a of the bottomed hole 2 in the illustrated example is a conical surface. When the drilling process proceeds and the bottomed hole 2 becomes deeper, a substantially right angle 3 is formed between the inner side surface 2b of the bottomed hole 2 and the upper surface 1a of the workpiece 1. At the time shown in the example of FIG. 5, the chamfering tip 16 is in a state of approaching the corner 3.

  As shown in FIG. 6, the side surface 2 b of the bottomed hole 2 and the workpiece 1, which are drilled with the chamfering chip 16 immediately before the drilling chip 15 performs a predetermined depth drilling with the drilling chip 15. The chamfering process of the corner 3 with the upper surface 1a is started. That is, as the drilling process progresses and the bottomed hole 2 becomes deeper, the position of the chamfering tip 16 also falls in the −Z direction. Therefore, at the timing immediately before the bottomed hole 2 reaches a predetermined depth. The machining surface 160 of the chamfering tip 16 contacts the corner 3. Then, by removing the corner 3 with the chamfering tip 16 that moves circularly along the rotation locus P shown in FIG. 3, the ring-shaped chamfered portion 4 is formed. The predetermined depth of the bottomed hole 2 is set to 1.5 mm, for example.

  As shown in FIG. 7, when the bottomed hole 2 reaches a predetermined depth, the cutting tool 10 is moved away from the workpiece 1 by moving the cutting tool 10 in the + Z direction by the lifting means 20, and the hole is drilled. Processing and chamfering are finished simultaneously. As described above, in the first example of the processing method according to the present invention, the side surface 2b of the bottomed hole 2 and the workpiece 1 are formed by the chamfering tip 16 immediately before drilling a predetermined depth by the drilling tip 15. When a chamfering process at a corner 3 with the upper surface 1a is started and a bottomed hole 2 having a predetermined depth is formed in the workpiece 1, a single cutting tool is used to finish the drilling process and the chamfering process at the same time. 10 can perform drilling and chamfering, and the processing time can be shortened.

[Second example of processing method using cutting tool]
Next, a second example of a processing method for forming a hole with a bottom in the workpiece 1A shown in FIG. 8 using the cutting tool 10 will be described. Also in the second example, the predetermined depth of the bottomed hole 2 is set to 1.5 mm, for example, as in the first example.

(1) First Machining Step As in the first example, the cutting tool 10 is lowered while the drilling tip 15 is circularly moved along the rotation locus P as shown in FIG. Thereby, as shown in FIG.8 (b), the hole 2 with a bottom is formed in the to-be-processed object 1. FIG. Similar to the first example, at the timing immediately before the bottomed hole 2 reaches a predetermined depth, the corner between the side surface 2b of the bottomed hole 2 and the top surface 1a of the workpiece 1A (see FIG. By removing (not shown), a ring-shaped chamfered portion 4 is formed. When the bottomed hole 2 reaches a predetermined depth, the first processing step is completed.

(2) Second machining step After performing the first machining step, the axial direction of the cutting tool 10 is fixed. That is, the movement of the cutting tool 10 in the axial direction by the elevating means 20 is stopped and the height position of the cutting tool 10 is fixed. Thereafter, as shown in FIGS. 9A and 9B, the cutting tool 10 and the object to be cut are moved by the horizontal moving means (not shown) while the hole-forming tip 15 and the chamfering tip 16 are circularly moved along the rotation locus P. By horizontally moving the workpiece 1A in a lateral direction (eg, + Y direction) that is relatively perpendicular to the axial direction, the side surface 2b of the bottomed hole 2 is laterally moved by the machining surface 151 of the drilling tip 15. I will sharpen it.

  As shown in FIGS. 10A and 10B, the horizontal width of the bottomed hole 2 is obtained by further moving the cutting tool 10 further in the + Y direction and further cutting the workpiece 1A in the lateral direction. Expand. At this time, since the height positions of the cutting tool 10 and the workpiece 1A are fixed, the bottomed hole 2 is elongated in the horizontal direction while maintaining a predetermined depth. Further, as shown in FIGS. 11A and 11B, the cutting tool 10 is horizontally moved in the + Y direction by a predetermined distance, and the drilling tip 15 cuts the side surface 2b and the bottom 5a of the bottomed hole 2. When the long hole 5 is formed and a corner (not shown) formed at the time of forming the long hole 5 is chamfered and removed by the chamfering tip 16, an oval chamfered portion 4 'is formed. The long hole 5 formed in the workpiece 1A has a predetermined depth, and its bottom 5a is finished to a flat surface. Thus, in the second example of the processing method according to the present invention, the first processing step for performing the drilling processing and the chamfering processing for forming the bottomed hole 2 having a predetermined depth, and the first processing step. Since the formed bottomed hole 2 is made into a long hole 5 and a second machining step for chamfering a corner formed at the time of forming the long hole 5 with a chamfering tip 16 is provided, a predetermined depth can be obtained with one cutting tool 10. The long hole 5 having a thickness can be formed efficiently, and the processing time can be shortened.

2 Second Embodiment [Modification of Cutting Tool]
A cutting tool 30 shown in FIGS. 12 to 15 is a modification of the cutting tool that forms a predetermined hole with a bottom by cutting a workpiece, and is disposed at a cylindrical main body 31 and a tip 32 of the main body 31. A plurality of cemented carbide tips. 13 to 15 illustrate the main body 31 with the tip 32 facing upward, but in practice, the workpiece is cut with the tip 32 facing downward.

  The plurality of cemented carbide chips in the modification include at least a drilling chip 36, a chamfering chip 37, and a side shaping chip 38. The side shaping tip 38 is made of, for example, a rectangular cutting blade, and has a machining surface 380 and a cutting edge 381 (see FIG. 15) for shaping the inner side surface of the bottomed hole drilled by the drilling tip 36. doing. The configurations of the drilling tip 36 and the chamfering tip 37 are the same as those of the cutting tool 10 described above. That is, the drilling tip 36 has processing surfaces 360 and 361 for performing drilling processing and a cutting edge 362, and the chamfering tip 37 has a processing surface 370 for performing chamfering processing. Note that the shape, size, material, and the like of the drilling tip 36, the chamfering tip 37, and the side shaping tip 38 are not particularly limited.

  The front end 32 of the main body 31 has an end face 32a. The end surface 32 a is recessed near the rotation center 300, which is the axis of the cutting tool 30, and is inclined to the outside of the main body 31. Notches 320, 321, and 322 are formed on the outer peripheral side of the tip 32. As shown in FIG. 13, a pocket 33 formed in accordance with the outer shape of the punching chip 36 is provided on the rear side of the notch 320. Similar to the cutting tool 10, a female screw (not shown) is formed on the side wall 323 connected to the pocket 33. When attaching the drilling tip 36 to the tip 32 of the main body 31, the drilling tip 36 is disposed in the pocket 33, and is screwed into the female screw formed on the side wall 323 by the male screw 17 and fastened. Thus, the drilling tip 36 can be fixed to the tip 32. As shown in FIG. 14, the notch 321 is provided with a pocket 34 formed according to the outer shape of the chamfering tip 37. Similar to the cutting tool 10, a chamfering tip 37 is disposed in the pocket 34, and is screwed into a female screw formed on a side wall (not shown) by a male screw 18 and fastened to be chamfered at a position retracted from the tip 32. The chip 37 can be fixed.

  As shown in FIG. 15, a pocket 35 formed in accordance with the outer shape of the side shaping tip 38 is provided on the rear side of the notch 322. When the side shaping tip 38 is disposed in the pocket 35, the side shaping tip 38 can be fixed to the distal end 32 by screwing and fastening with a female screw formed on a side wall (not shown) with the male screw 19. In the cutting tool 30, the height of the cutting edge 381 of the side shaping tip 38 and the height of the cutting edge 362 of the drilling tip 36 coincide with each other as indicated by a dashed line. Moreover, in the cutting tool 30, as shown in FIG. 16, the side shaping tip 38 is disposed at a position opposite to the position where the drilling tip 36 is disposed, and the rotational balance of the cutting tool 30 is good. It has become.

[Machining method using a modification of cutting tool]
Next, a processing method for forming a hole with a bottom in the workpiece 1B shown in FIG. 16 using the cutting tool 30 will be described. A rotation locus P1 indicated by a dotted line in the drawing is a region in which the outermost diameter (cutting edge 362) of the drilling tip 36 moves circularly when the cutting tool 30 rotates about the rotation center 300, and side shaping. This is also the region where the outermost diameter (blade edge 381) of the cutting tip 38 moves circularly.

  As shown in FIG. 17, the cutting tool 30 and the workpiece 1B are moved relative to each other by, for example, the lifting means 20 while rotating the main body 31 in a direction indicated by an arrow L by a motor (not shown) to circularly move the drilling tip 36. Then, the cutting tool 30 is moved in the axial direction (−Z direction), and the drilling tip 36 is cut into the upper surface 1a of the workpiece 1B to make a circular hole. Thereby, as shown in FIG. 18, the hole 6 with the bottom which has the bottom 6a in the to-be-processed object 1B is formed. The bottom 6a of the bottomed hole 6 is a conical surface. At the timing just before the bottomed hole 6 reaches a predetermined depth, the side surface 6b inside the bottomed hole 6 drilled with the drilling tip 36 by the chamfering tip 37 and the upper surface 1a of the workpiece 1B. The chamfering process of the corner 7 is started, and the ring-shaped chamfered portion 8 is formed.

  Furthermore, in the cutting tool 30, the side shaping tip 38 located at a position facing the drilling tip 36 moves circularly along the rotation locus P1 shown in FIG. The side surface 6b of the hole 6 is shaved with the side surface shaping tip 38 and shaped. As a result, the surface state of the side surface 6b of the bottomed hole 6 is improved. Then, as shown in FIG. 19, when the bottomed hole 6 reaches a predetermined depth, the cutting tool 30 is moved away from the workpiece 1B by moving the cutting tool 30 in the + Z direction by the lifting and lowering means 20, Drilling, side shaping, and chamfering are completed simultaneously.

  Here, when drilling is performed on the workpiece 1 with only the drilling tip 15 of the cutting tool 10, for example, as shown in FIG. 20, the side surface 2b of the bottomed hole 2 has irregularities. As a result, the surface condition becomes rough. On the other hand, by subjecting the side surface 6b of the bottomed hole 6 to the side surface shaping with the side surface shaping tip 38 immediately after the hole making tip 36 of the cutting tool 30 is drilled into the workpiece 1B, for example, As shown in FIG. 21, the side surface 6b of the bottomed hole 6 is shaped into a straight line. Thus, since the cutting tool 30 is provided with the drilling tip 36, the chamfering tip 37, and the side shaping tip 38 at the tip 32 of the main body 31, there are three types of cutting tools 30. Processing (drilling, chamfering and side shaping) can be performed in parallel, and in addition to chamfering of the corner 7 between the side surface 6b of the bottomed hole 6 and the top surface 1a, the shape of the side surface 6b of the bottomed hole 6 Can be finished in a good surface state.

1, 1A, 1B: Workpiece 1a: Top surface 2: Bottomed hole 2a: Bottom 2b: Side surface 3: Corner 4: Chamfered portion 5: Slotted hole 6: Bottomed hole 6a: Bottom 6b: Side surface 7: Corner 8: Chamfer 10: Cutting tool 100: Center of rotation 11: Main body 12: Tip 12a: End surface 120, 121: Notch 122: Side wall 13, 14: Pocket 15: Drilling insert 150, 151: Work surface 152: Cutting edge 16 : Chamfering tip 160: Processed surface 17, 18, 19: Male screw 20: Lifting means 30: Cutting tool 300: Center of rotation 31: Main body 32: Tip 32 a: End surface 320, 321, 322: Notch 323: Side wall 33 34, 35: Pocket 36: Drilling tip 360, 361: Machining surface 362: Cutting edge 37: Chamfering tip 370: Machining surface 38: Side shaping tip 380: Machining surface 3 1: cutting edge

Claims (3)

A cutting tool in which a plurality of cemented carbide tips are disposed at the tip of a cylindrical body and a workpiece are relatively rotated about the axis of the cutting tool and moved relatively in the axial direction. A cutting tool for cutting a workpiece with
The plurality of carbide tips include a drilling tip,
At least a chamfering tip,
The drilling tip is disposed at the tip of the main body, the chamfering tip is disposed at a position retracted from the tip,
Chamfering of the corner between the side surface of the bottomed hole drilled by the chamfering tip with the chamfering tip and the upper surface of the workpiece is started immediately before the chamfering tip is drilled to a predetermined depth. And
A cutting tool that terminates the drilling and chamfering simultaneously. A method for machining a hole with a bottom using the cutting tool according to claim 1,
The cutting tool and the workpiece are moved relative to each other in the axial direction of the cutting tool to cut the drilling tip into the workpiece, and the drilling tip is drilled to a predetermined depth. Immediately before the chamfering of the corner between the side surface of the bottomed hole drilled with the drilling tip and the upper surface of the workpiece is started by the chamfering tip,
A machining method for simultaneously finishing the drilling and the chamfering. A method for machining a hole with a bottom using the cutting tool according to claim 1,
The cutting tool and the workpiece are moved relative to each other in the axial direction of the cutting tool to cut the drilling tip into the workpiece, and the drilling tip is drilled to a predetermined depth. Immediately before the chamfering, the chamfering of the corner between the side surface of the bottomed hole drilled by the drilling tip and the top surface of the workpiece is started by the chamfering tip, and the bottomed hole of the predetermined depth is started. A first processing step to be formed;
After the first machining step, the axial position of the cutting tool is fixed, the cutting tool and the workpiece are moved relatively in a direction perpendicular to the axial direction, and the bottomed hole And a second processing step of chamfering a corner formed at the time of forming the long hole with the chamfering tip.

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