JP3111276U - Chamfering end mill - Google Patents

Abstract

[PROBLEMS] A conventional chamfering end mill has a twist angle of a twisting blade that is at most 30 °, so that the load on the cutting edge and workpiece is still large, and there are restrictions on manufacturing, and the number of twisting blades is three. However, there was a return or burr at the end of the cutting surface, the life was short, and it was difficult to increase the processing speed.
A chamfering end mill 10 according to the present invention is a chamfering end mill in which a chamfered portion P is provided on a workpiece W. The chamfering end mill 10 has four outer peripheral blades 11 having a twist angle of 45 ° and a tip diameter 13 of about 2 mm.
[Selection] Figure 1

Description

  The present invention relates to a chamfered end mill. More specifically, the present invention suppresses damage to the cutting surface due to cutting edge burrs, burrs, and cutting waste, and provides a finished surface with a smooth chamfered portion, and also improves cutting ability and durability. The present invention relates to a chamfering end mill that can be used.

  A conventional chamfering end mill of this type has an outer peripheral blade at an outer peripheral surface and an end portion, and rotates to cut an end portion of a workpiece to provide a predetermined chamfered portion. The peripheral blade type includes a straight blade type and a twisted blade type. It is known that a twisted blade type and a stronger twist angle have an effect of finishing the cutting surface more smoothly than a straight blade type. It is also known that a larger number of outer peripheral cutting edges is suitable for high-speed machining. Usually, as a chamfering end mill, one having two or three outer peripheral blades is known.

  Since the contact portion between the outer peripheral cutting edge and the workpiece of the straight edge type chamfered end mill is simultaneously contacted from the end mill side to the shank side, the cutting resistance (load) is large. Therefore, the finished surface of the chamfer is difficult, and there is a drawback that the end of the surface is likely to return and burrs, and that the outer peripheral cutting edge wears out quickly and wears out. In this respect, the chamfered end mill of the twisted blade type always moves from the end mill tip side to the shank side at the contact part of the outer peripheral cutting edge, and the cutting resistance is small. Can be suppressed, and the finished surface can be smoothed, while wear of the outer peripheral cutting edge and wear such as chipping can be suppressed.

  However, in the conventional chamfering end mill, the twist angle of the twisting blade is 30 ° at most, so the load on the cutting edge and the workpiece is still large, and there are restrictions on manufacturing, and the number of twisting blades is three. It was the limit, and there was a return and burr at the end of the cutting surface, the life was short, and it was difficult to increase the processing speed.

  The present invention has been made to solve the above-described problems, and can remarkably suppress the return of the end of the cutting surface and burrs, and can prolong the service life, thereby increasing the processing speed. It aims to provide a chamfered end mill that can be used.

  A chamfering end mill according to claim 1 of the present invention is a chamfering end mill in which a chamfered portion is provided on a workpiece, and has a plurality of outer peripheral blades having a twist angle of at least 45 °.

  A chamfering end mill according to claim 2 of the present invention is a chamfering end mill in which a chamfered portion is provided on a workpiece, and has four outer peripheral blades having a twist angle of at least 45 °.

  A chamfering end mill according to claim 3 of the present invention is a chamfering end mill in which a chamfered portion is provided on a workpiece, and has four outer peripheral blades having a twist angle of at least 45 °, and a tip diameter of about 2 mm. It is characterized by.

  According to the invention described in claims 1 to 3 of the present invention, it is possible to remarkably suppress the return of the end portion of the cutting surface and burrs, and to extend the life, thereby increasing the processing speed. A chamfered end mill can be provided.

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. In each figure, FIG. 1 is a view showing an embodiment of a chamfering end mill of the present invention, (a) is a side view thereof, (b) is a plan view thereof, and FIG. 2 is shown in FIG. FIG. 3 and FIG. 4 are sectional views showing a state in which a chamfered portion is provided on a workpiece using the chamfering end mill shown in FIG.

  The chamfering end mill 10 of the present embodiment is formed of an outer peripheral blade 11 and a shank 12 as shown in FIGS. 1A and 1B, for example, and a chamfered portion having a 45 ° tapered surface is provided on the workpiece W. Used when. As shown in FIG. 1 (a), the outer peripheral blade 11 has a taper half angle of 45 ° from the tip side toward the shank 12, and the shank from the tip side as shown in FIG. It is formed to be spirally twisted at an angle of 45 ° toward the outer peripheral surface of the plate. Four outer peripheral blades 11 are formed at equal intervals in the circumferential direction. Further, a tip surface 13 having a tip diameter of 2 mm, for example, is formed at the tip on which the four outer peripheral blades 11 are formed.

  Between each outer peripheral blade 11, a blade groove 14 is formed in a spiral shape along each outer peripheral blade 11, and the cutting waste generated by the outer peripheral blade 11 is discharged to the shank 12 side through these blade grooves 14. is there. The blade groove 14 gradually increases in width from the tip surface side toward the shank 12 side and gradually increases in depth at a constant ratio, and each outer peripheral blade 11 extends from the tip surface 13 toward the shank side. The width is formed so as to gradually increase at a constant ratio. For this reason, as for the cross-sectional shape orthogonal to the axial direction from the front end surface 13 to the shank 12, the width and depth of each blade groove 14 and the width of each outer peripheral blade 11 are shown in FIG. Thus, it is formed at the same ratio as the front end surface 13.

  The cutting edge 11 </ b> A of the outer peripheral blade 11 protrudes in the outer peripheral direction, and its inner surface is curved to form a rake face 11 </ b> B of the blade groove 14. This rake face 11B scoops up the cutting waste generated when the workpiece (see FIGS. 3 and 4) W is cut by the cutting edge 11A of the outer peripheral edge 11, and discharges the scraped cutting waste from the blade groove 14 to the shank 12 side. To do. Further, the outer peripheral rake angle θ of the rake face 11B can be appropriately set within a range of, for example, −3 ° to + 12 ° in accordance with the characteristics of the workpiece W as shown in FIG. Thus, by setting the outer peripheral rake angle θ in accordance with the hardness of the workpiece W and the like, the machinability and the durability of the cutting edge 11A can be improved. The outer peripheral rake angle θ shown in FIG. 2 is an angle indicating a positive magnitude.

  Now, in this embodiment, since the outer peripheral blade 11 is formed with a 45 ° twist angle, the workpiece W can be cut much more smoothly than the conventional case of 30 °. The load on the workpiece W is also significantly reduced, and the occurrence of returns and burrs can be significantly suppressed. In addition, since the chamfered end mill 10 has four outer peripheral blades 11, the workpiece W can be cut by the four outer peripheral blades 11 while the chamfering end mill 10 rotates once, and compared with the one having less than four outer peripheral blades. In addition, the generation amount of cutting waste per outer peripheral blade is small, and a large twist angle of 45 ° is more powerful than the conventional case of 30 °, because the cutting waste is strongly discharged to the shank 12 side. It is possible to significantly reduce damage to the workpiece cutting surface due to cutting waste, and to form a smooth finished surface.

  Next, a case where the chamfered portion P is provided in the groove T formed in the workpiece W using the chamfered end mill 10 of the present embodiment will be described with reference to FIG.

  First, in a state where the chamfering end mill 10 is rotated at a high speed via a rotation drive mechanism (not shown), the outer peripheral edge 11 of the chamfering end mill 10 is applied to the corner of the groove T of the workpiece W with a predetermined pressure as shown in FIG. When contacted, the outer peripheral blade 11 that rotates at a high speed cuts into the corner of the groove T and cuts the workpiece W.

  The outer peripheral blade 11 is cut into the corner of the groove T from the tip side to the shank 12 side with a helix angle of 45 ° which is much larger than the conventional one, thereby smoothly cutting the corner of the groove T. At this time, since the torsion angle of the outer peripheral blade 11 is large, the load on the outer peripheral blade 11 is small and the load on the workpiece W is also small. The cutting waste generated by cutting from the front end side of the outer peripheral blade 11 to the shank 12 side is scooped into the rake face 11B of the outer peripheral blade 11, and this cutting waste obtains a large centrifugal force from the outer peripheral blade 11 to 45 °. The spiral blade groove 14 is smoothly discharged to the shank 12 side.

  Since the workpiece W is cut by the four peripheral blades 11 while the chamfering end mill 10 rotates once, the cutting amount per peripheral blade is small, and the cutting waste is chamfered when the cutting waste is discharged from the blade groove 14. The chamfered portion P is hardly damaged by sliding on the P, and the chamfered portion P becomes an extremely smooth finished surface.

  As described above, since the load applied to the outer peripheral blade 11 at the time of cutting is remarkably small as compared with the conventional case, the return and the generation of burrs at the chamfered portion P, which is the cutting surface, can be remarkably suppressed and compared with the conventional case. Thus, the life of the chamfer end mill 10 can be remarkably increased, and the amount of cutting generated in the blade groove 14 is small, so that the smooth finished surface can be smoothly discharged to the shank 12 side through the blade groove 14. The chamfered part P which has can be formed. Furthermore, since the load applied to the outer peripheral blade 11 is much smaller than before, the rotational speed of the chamfered end mill 10 can be increased, and the processing speed of the chamfered portion P can be significantly increased.

  Although the case where the chamfered portion P is provided in the groove T has been described with reference to FIG. 3, the chamfered portion P can be similarly provided in the hole H formed in the workpiece W as shown in FIG. 4.

  Since the tip diameter of the chamfered end mill 10 of this embodiment is 2 mm, if the hole H has an inner diameter of 2 mm or more, the tip of the chamfered end mill 10 can be accurately positioned with respect to the hole H. The chamfered portion P can be provided with high accuracy by aligning the center of the chamfered portion P with the center of the hole H.

  As described above, according to the present embodiment, since there are four outer peripheral blades having a torsion angle of at least 45 °, the processing speed can be increased and the return and burr can be remarkably suppressed, and the finished surface of the chamfered portion P can be obtained. Further, the life of the chamfered end mill 10 can be significantly extended. In addition, since the load on each outer peripheral blade 11 is much smaller than the conventional one, the workpiece W can be processed at high speed.

  In addition, according to the present embodiment, since the tip diameter is 2 mm, when the chamfered portion P is provided for the hole H having a diameter of at least 2 mm, the axial centers of the hole H and the chamfered portion P are matched. Thus, the chamfered portion P can be formed with high accuracy.

  In the above-described embodiment, the chamfering end mill 10 having a twist angle of 45 ° and four outer peripheral blades 11 has been described. However, as the number of outer peripheral blades increases and the twist angle increases, one outer peripheral blade is obtained. It is preferable because the load at the time of the cutting is reduced and the amount of cutting waste generated in the blade groove is reduced. Further, the outer peripheral blades may be plural, and may be three less than four. Moreover, although the said embodiment demonstrated the chamfering end mill whose taper half angle is 45 degrees, this invention is applicable also to a chamfering end mill of 45 degrees or more (for example, 60 degrees). The present invention is not limited to the above embodiment, and can be appropriately modified as necessary.

  The present invention can be suitably applied when a chamfer is provided on various workpieces.

It is a figure which shows one Embodiment of the chamfering end mill of this invention, (a) is the side view, (b) is the top view. It is a top view which expands and shows the front end surface shown to (b) of FIG. It is sectional drawing which shows the state which provides a chamfering part in a hole using the chamfering end mill shown in FIG. It is sectional drawing which shows the state which provides a chamfering part in a hole using the chamfering end mill shown in FIG.

Explanation of symbols

10 Chamfering end mill 11 Peripheral blade 12 Shank 13 Tip surface W Workpiece

Claims (3)

  A chamfering end mill having a chamfered portion provided on a workpiece, the chamfering end mill having a plurality of outer peripheral blades having a twist angle of at least 45 °.   A chamfering end mill having a chamfered portion on a workpiece, the chamfering end mill having four outer peripheral blades having a twist angle of at least 45 °. A chamfering end mill having a chamfered portion on a workpiece, the chamfering end mill having four outer peripheral blades having a twist angle of at least 45 ° and a tip diameter of about 2 mm.

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