JP2005022003A - Rotary cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary cutting tool of high work efficiency in cutting work such as boring of a cutting material or finish-machining of a bore, and in chamfering work of both end faces of the bore. <P>SOLUTION: This rotary cutting tool is provided with a shank, a body part continuous with the shank, and a cutting edge formed at the anti-shank side tip part of the body part. The body part is provided with a first chamfering edge reduced in diameter toward the shank side from the cutting edge side, and a second chamfering edge positioned on the shank side from the first chamfering edge and enlarged in diameter toward the shank side from the cutting edge side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Industrial application fields]
The present invention relates to a rotary cutting tool for performing a cutting process and a chamfering process such as drilling or hole finishing on a workpiece.
[0002]
[Prior art]
Conventionally, when drilling and chamfering both ends of a hole in a workpiece, first, a hole is drilled in the workpiece, and then one side opening and the other side of the hole drilled in the workpiece are opened. It was performed in the process of chamfering the part. Referring to FIG. 5 in detail, first, as shown in FIG. 5A, from the shank 104, the main body portion 102 continuous from the shank 104, and the cutting blade 103 formed at the end opposite to the shank of the main body portion 102. A rotating cutting tool such as a drill 101 for drilling is attached to a spindle (not shown) of a machining center, and a hole 132 which is a through hole is formed from one side 133 of the workpiece 131 fixed on the mounting table. Drilling is performed, and then the drill 101 is retracted from the hole 132 of the workpiece 131 and removed from the spindle of the machining center. Subsequently, as shown in FIG. 5A, the shank 144 and the main body portion 142 continuing from the shank 144 and the opposite end of the main body portion 142 are inclined so that the diameter increases from the end toward the shank 144. A chamfering tool 141 having a chamfering blade 143 is attached to the spindle of the machining center, and the chamfering blade 143 of the chamfering tool 141 is brought into contact with the inner peripheral surface of one side opening 134 for inserting the rotary cutting tool. I do. Finally, chamfering is performed on the inner peripheral surface of the other opening 134 of the workpiece 131. At this time, if the workpiece 131 can be easily inverted, the workpiece 131 is inverted, Chamfering is performed on the inner peripheral surface of the other opening 135 with the same chamfering tool 141 as the inner peripheral surface of the one opening 134. However, in a machining center or the like, when the workpiece 131 once fixed is reversed, the work man-hour increases because the workpiece 131 must be once removed from the mounting table and inverted and then fixed again on the mounting table. Further, depending on the shape of the work to be cut, a chamfering tool may be inserted only from one side opening. Therefore, as shown in FIG. 5C, the shank 146 and the main body 147 and the main body 147 continuous from the shank 146 are provided. The other side chamfering tool 145 having the other side chamfering blade 147 that is inclined so as to have a smaller diameter from the end on the side opposite to the shank of the portion 147 toward the shank 146 is provided in the hole 132 of the workpiece 131 on the one side opening 134. Inserting from the inner periphery, chamfering of the inner peripheral surface of the other opening 135 was performed. The same applies to the case where chamfering is performed after a hole is formed in advance in the workpiece by cutting the inner peripheral surface of the hole with a rotary cutting tool such as an end mill and finishing. After finishing the inner peripheral surface of the hole of the workpiece with an end mill, the inner peripheral surface of the one side opening was chamfered with a chamfering tool, and then the inner peripheral surface of the other side opening was chamfered. .
[Problems to be solved by the invention]
[0003]
In the cutting process in which holes are cut or chamfered after drilling or finishing of the workpiece as described above, it is necessary to change the rotary cutting tool according to the processing content during each machining. there were. Therefore, before chamfering, remove the rotary cutting tools such as drills and end mills that were previously machined from the workpiece and remove them from the main spindle of the machining center, and then install the chamfering tools. Since it had to be done, the work man-hours increased and the work efficiency decreased.
[0004]
Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a rotary cutting tool having high work efficiency of cutting work such as drilling or finishing of a workpiece and chamfering both ends of a hole. .
[0005]
[Means for Solving the Problems]
The present invention has the following configuration.
[0006]
1. In a rotary cutting tool comprising a shank and a main body continuous from the shank and a cutting blade formed at the tip end on the anti-shank side of the main body, the main body has a first chamfer with a small diameter from the cutting blade side toward the shank. A blade, and a second chamfering blade positioned on the shank side from the first chamfering blade and having a larger diameter from the cutting blade side toward the shank side.
[0007]
2. The axial length between the first chamfering blade and the second chamfering blade is substantially the same as the axial length between the chamfered portions of the workpiece.
[0008]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0009]
FIG. 1A shows a drill 1 which is a rotary cutting tool according to an embodiment of the present invention. Reference numeral 4 denotes a rod-shaped shank, and the main body 2 extends continuously from the shank 4. A cutting blade 3 for drilling the workpiece 31 is provided at the tip of the main body 2 on the side opposite to the shank, and the diameter of the cutting blade 3 is smaller than the cutting blade 3 toward the shank 4 from the cutting blade 3 toward the shank 4. The 1st chamfering blade 5 which inclines so that it may become is provided. A second chamfering blade 6 is provided on the shank 4 side of the first chamfering blade 5 so as to be inclined so as to increase in diameter from the cutting blade 3 direction toward the shank 4 direction. A straight portion 7 is formed between the first chamfering blade 5 and the second chamfering blade 6, and the straight portion 7 has a maximum width t larger than the maximum width T of the cutting blade shown in FIG. It is set small and formed so as not to interfere with the inner peripheral surface of the hole 32 when the workpiece 31 is chamfered. Reference numeral 8 denotes a scrap relief groove which is recessed parallel to the axis of the drill 1.
[0010]
The drilling process of the workpiece 31 using the drill 1 as described above and the process of chamfering both ends of the hole will be described with reference to FIG. First, the shank 4 of the drill 1 is mounted on the spindle (not shown) of the machining center, and the workpiece 31 is placed on a plate-like mounting table and fixed, and then the drill 1 is rotated to the workpiece 31. Move forward. As shown in FIG. 2A, the drill 1 abuts against one side surface 33 of the workpiece 31, starts drilling, and forms a hole 32 that is a through hole having a desired diameter. At this time, the axis of the drill 1 is located on the same axis as the center of the hole 32. After forming the hole 32, the drill 1 is further advanced as shown in FIG. The center position C of the drill 1 is slightly decentered with respect to the center c of the hole 32 in a state in which the center of the drill 1 protrudes outward from the other side opening 35 of the workpiece 31. Subsequently, as shown in FIG. 2C, the first chamfering blade 5 is brought into contact with the inside of the other side opening 35 and is fed along an inner circumference of the other side opening 35 to chamfer the other side opening 35. I do. Finally, as shown in FIG. 2D, the drill 1 is further advanced so that the second chamfering blade 6 is brought into contact with the inner peripheral surface of the one side opening 34 of the hole 32 of the workpiece 31 and the one side opening 34. A circular arc is fed along the inner periphery of the inner surface, and the one side opening 34 is chamfered. Thereafter, the eccentric drill 1 is returned to the center position of the hole 32 of the workpiece 31, the drill 1 is retracted, and the machining is completed.
[0011]
Therefore, according to the drill 1 as described above, the shank 4, the main body portion 2 continuous from the shank 4, and the cutting blade 3 provided at the tip end on the anti-shank side of the main body portion 2 are provided. On the side, a first chamfering blade 5 having a small diameter from the cutting blade 3 direction toward the shank 4 direction is provided, and the first chamfering blade 5 is closer to the shank 4 side and is larger from the cutting blade 3 direction toward the shank 4 direction. Since the second chamfering blade 6 having a diameter is provided, it is possible to perform drilling and chamfering on the workpiece 31 with the same rotary cutting tool.
[0012]
Next, another embodiment will be described with reference to FIGS. FIG. 3 shows a throw-away end mill 51 which is another rotary cutting tool. The end mill 51 has a shank 54 and a holder 52 that is continuous from the shank 54 and corresponds to the main body. A first tip 61 having a substantially parallelogram is attached to the tip of the holder 52 on the side opposite to the shank. The first tip 61 has a cutting edge 53 formed on one tip side, and a first chamfering edge 55 that is inclined so as to have a small diameter from the cutting blade 53 side toward the shank 54 side on the other rear end side. Yes. On the side of the shank 54 from the first tip 61 of the holder 52, there is a substantially triangular second tip 62 in which a second chamfering blade 56 that is inclined so as to increase in diameter from the cutting blade 53 side toward the shank 54 side is formed. It is attached. As shown in FIG. 4A, the axial length L between the first chamfering blade 55 of the first tip 61 and the second chamfering blade 56 of the second tip 62 is substantially equal to the axial length l of the workpiece 31. The length in the direction perpendicular to the axis from the axis of the end mill 51 at the end of the first chamfering blade 55 on the side of the cutting blade 53 and the end of the second chamfering blade 56 on the shank 54 is the tip side of the cutting blade 53. It is shorter than the length in the direction perpendicular to the axis from the axis of the end mill 51 at the end.
[0013]
A method of finishing and chamfering both ends of the hole 72 using the end mill 51 will be described with reference to FIG. First, the shank 54 of the end mill 51 is mounted on a headstock (not shown) of a machining center, and a workpiece 71 in which a hole 72 is formed in advance by rough machining is placed on a plate-like mounting table and fixed. Then, the end mill 51 is advanced toward the workpiece 71 while rotating. As shown in FIG. 4A, the end mill 51 is inserted into the inside of the hole 72 from the one side opening 74 of the hole 72 of the workpiece 71, and the cutting blade 53 is brought into contact with the inner periphery of the hole 72 by cutting. Finishing is started, and the end mill 51 advances by arc feed around the center of the hole 72 inside the hole 72 of the workpiece 71, and finishes the finishing inside the hole 72. At this time, the first chamfering blade 55 of the first tip 61 and the second chamfering blade 56 of the second tip 62 are not in contact with the inner peripheral surface of the hole 72 as shown in FIG. Next, the center of the end mill 51 is slightly moved to the inner peripheral surface side of the hole 72, and the first chamfering blade 55 of the first tip 61 is moved to the inner peripheral surface of the other opening 75 as shown in FIG. The second chamfering blade 56 of the second tip 62 is brought into contact with the inner peripheral surface of the one side opening 74 so that the end mill 51 is fed in an arc along the inner peripheral surface of the hole 72, and the inner peripheral surface of the other side opening 75 and A chamfering process is performed on the inner peripheral surface of the one-side opening 74. When the chamfering is completed, the center of the end mill 51 is moved to the center side of the hole 72 of the workpiece 71, and the end mill 51 is retracted in a state where the cutting blade 53 of the end mill 51 does not contact the inner peripheral surface of the hole 72. Finishing the inner peripheral surface of the hole 72 of the workpiece 71 and chamfering both ends of the hole 72 are finished.
[0014]
Therefore, according to the present invention as described above, the first tip having the shank 54 and the holder 52 that is continuous from the shank 54 and corresponds to the main body, and the cutting blade 53 is formed at the tip of the holder 52 opposite to the shank. 61 is attached, and a first chamfering blade 55 having a smaller diameter from the cutting blade 53 side toward the shank 54 side is formed on the shank 54 side of the cutting blade 53 of the first tip 61. Since a substantially triangular second tip 62 having a second chamfering blade 56 having a large diameter from the cutting blade 53 side toward the shank 54 side is attached to the shank 54 side, the workpiece is cut with the same rotary cutting tool. The finishing process of 71 holes 72 and the chamfering process of both ends of the holes 72 can be performed. In addition, when the axial length L between the first chamfering blade 55 and the second chamfering blade 56 is substantially the same as the axial length l of the hole 72 of the workpiece 71, the one-side opening 74 The chamfering of the other side opening 75 can be performed simultaneously.
[0015]
Note that the structure for simultaneously chamfering both ends of the hole is not limited to the end mill, and chamfering for both ends can be performed simultaneously with the same structure as the end mill in all rotary cutting tools such as drills.
[0016]
【The invention's effect】
As described above, according to the present invention, in the rotary cutting tool including the shank, the main body portion continuous from the shank, and the cutting blade formed at the distal end portion on the anti-shank side of the main body portion, the main body portion has the shank from the cutting blade side. The same chamfering tool is provided with a first chamfering blade having a smaller diameter toward the side and a second chamfering blade positioned on the shank side from the first chamfering blade and having a larger diameter from the cutting blade side toward the shank side. Since cutting and chamfering such as drilling and finishing of workpieces can be performed with, there is no need to change the rotary cutting tool in accordance with changes in machining content, so the increase in work man-hours is suppressed and work Increases efficiency. In addition, since the cutting blade, the first chamfering blade, and the second chamfering blade are individually formed, the hole and each chamfered portion of the workpiece can be formed at different taper angles at the time of processing.
[0017]
Further, if the axial length between the first chamfering blade and the second chamfering blade of the rotary cutting tool is substantially the same as the axial length between the chamfered parts of the workpiece, one of the workpieces Since the inner circumferential surface of the side opening and the inner circumferential surface of the other opening can be chamfered at the same time, an increase in work man-hours is further suppressed and work efficiency is increased.
[Brief description of the drawings]
1A and 1B show a rotary cutting tool according to a first embodiment of the present invention, in which FIG. 1A is a front view and FIG.
FIG. 2 is a partial cross-sectional front view showing a cutting process using a rotary cutting tool according to a first embodiment of the present invention.
FIG. 3 is a front view showing a rotary cutting tool according to a second embodiment of the present invention.
FIG. 4 is a partial sectional plan view showing a cutting process by a rotary cutting tool according to a second embodiment of the present invention.
FIG. 5 is a partial cross-sectional plan view showing a cutting process using a conventional rotary cutting tool.
[Explanation of symbols]
2 Main body 3 Cutting blade 4 Shank 5 First chamfering blade 6 Second chamfering blade 31 Workpiece 52 Main body 53 Cutting blade 54 Shank 55 First chamfering blade 56 Second chamfering blade 71 Workpiece L Axial length l Axial length

Claims (2)

A shank (4, 54), a main body portion (2, 52) continuous from the shank (4, 54), and a cutting blade (3, 53) formed at the tip end portion on the opposite side of the main body portion (2, 52) A first chamfering blade (5,55) having a small diameter from the cutting blade (3,53) side toward the shank (4,54) side of the main body (2,52). ) And the first chamfered blade (5, 55) located on the shank (4, 54) side, and has a larger diameter from the cutting blade (3, 53) side toward the shank (4, 54) side. A rotary cutting tool comprising a second chamfering blade (6, 56). The axial length (L) between the first chamfering blade (5, 55) and the second chamfering blade (6, 56) is the axis between the chamfered portions of the workpiece (31, 71). The rotary cutting tool according to claim 1, characterized in that it is substantially the same as the length (l) in the direction.

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